99-3

Planning 

Report

Benefit Analysis of IGBT

Power Device Simulation

Modeling

Prepared by:

Research Triangle Institute

for

National Institute of

Standards & Technology

Program Office

Strategic Planning and

Economic Analysis Group

April 1999

U.S Department of Commerce

Technology Administration
RTI Project Number

7007-02

Benefit Analysis of IGBT Power

Device Simulation Modeling

Final Report

April 1999

Prepared for

Gregory Tassey, Ph.D.

National Institute of Standards and Technology

Acquisition and Assistance Division

Building 101, Room A1000

Gaithersburg, MD 20899-0001

Prepared by

Michael P. Gallaher, Ph.D.

Sheila A. Martin, Ph.D.

Research Triangle Institute

Center for Economics Research

Research Triangle Park, NC 27709
iii

Contents

Executive Summary ES-1

1. Introduction 1-1

1.1 Project Objectives............................................................. 1-2

1.2 Motivation for NIST’s Involvement .................................... 1-3

1.3 NIST’s Contributions to Mathematical Modeling of

IGBT Power Devices ......................................................... 1-4

1.4 Overview of Analysis Approach ........................................ 1-5

2. The IGBT Supply Chain 2-1

2.1 IGBT Power Devices ......................................................... 2-1

2.2 End-Use Applications........................................................ 2-2

2.2.1 Automotive Applications ....................................... 2-2

2.2.2 Motor Controls ...................................................... 2-4

2.2.3 Power Control Equipment...................................... 2-5

2.2.4 Lighting ................................................................. 2-7

2.2.5 Future Trends and Applications.............................. 2-7

2.3 IGBT Simulation Modeling Supply Chain .......................... 2-8

2.3.1 Software Companies............................................ 2-10

2.3.2 Device Manufacturers.......................................... 2-10

2.3.3 Applications Manufacturers ................................. 2-14

3. Technical Impacts of Simulation Modeling of

IGBT Devices 3-1

3.1 Impacts on R&D Efficiency................................................ 3-1

3.1.1 Description of the System Design Process

Without Simulation Modeling................................ 3-4
iv

3.1.2 Description of the System Design Process With

Simulation Modeling ............................................. 3-5

3.1.3 Summary of the Technical Impacts of

Simulation Modeling on System Design

Process.................................................................. 3-7

3.2 Impact on Transaction Costs.............................................. 3-7

3.3 Impact on Production Costs............................................... 3-8

3.4 Impact on Product Quality and Performance ..................... 3-8

4. Methodology for Estimating Economic Impacts 4-1

4.1 Economic Model............................................................... 4-1

4.1.1 Net Benefits from Simulation Modeling of

IGBTs.................................................................... 4-3

4.1.2 Net Benefits from NIST’s Contributions to

Simulation Modeling of IGBTs ............................... 4-4

4.2 Calculating Benefit and Cost Categories ............................ 4-5

4.2.1 Benefits Categories ................................................ 4-5

4.2.2 Cost Categories...................................................... 4-8

4.3 Aggregating Economic Impacts........................................ 4-10

4.3.1 Measures of Social Return to NIST

Expenditures........................................................ 4-12

4.4 Impact Measures............................................................. 4-12

4.5 Data Collection Procedures ............................................ 4-12

5. Analysis Results 5-1

5.1 Overview of Methodology and Taxonomy......................... 5-2

5.2 Summary of Interviews...................................................... 5-3

5.3 Technical and Economic Impacts of IGBT Simulation

Modeling .......................................................................... 5-4

5.3.1 R&D Efficiency Impacts ......................................... 5-4

5.3.2 Transaction Cost Impacts..................................... 5-11

5.3.3 Production Costs and Product

Quality/Performance Impacts............................... 5-12

5.4 Aggregate Design Impacts ............................................... 5-18

5.4.1 Research Facility-Level Benefits ........................... 5-19

5.4.2 Weighting Research Facility-Level Benefits to

National Benefits................................................. 5-21

5.4.3 Net Benefits to Industry ....................................... 5-22
v

5.5 Industries’ Assessment of NIST’s Contributions and

NIST’s Share of Total Benefits.......................................... 5-24

5.6 NIST’s Program Costs ...................................................... 5-25

5.7 Benefit-Cost Ratio and Social Rate of Return from the

NIST Program ................................................................. 5-28

6. Market Barriers and the Role of NIST 6-1

6.1 Barriers to the Development of Simulation Modeling

Software Products ............................................................. 6-2

6.1.1 Barriers to the Development and Incorporation

of IGBT Modeling Capabilities into Simulation

Software ................................................................ 6-2

6.1.2 Competition in the IGBT Simulation Modeling

Software Market .................................................... 6-5

6.2 Barriers to the Adoption of Simulation Modeling ............... 6-7

6.2.1 Assimilation and Overhead Costs........................... 6-7

6.2.2 Effort and Expense Required to Characterize

IGBT Models ......................................................... 6-7

6.2.3 Modeling Limitations Associated with

Confidential Information........................................ 6-8

6.2.4 Weak Models for Non-IGBT Components............ 6-10

6.2.5 Missing Analysis Capabilities in Simulation

Software .............................................................. 6-10

6.3 Future Adoption Trends and Issues .................................. 6-11

6.4 Future Roles for NIST ...................................................... 6-13

References R-1

Appendixes

A Background Information on IGBTs.....................................A-1

B Acceleration Effect ............................................................ B-1

C Survey Instrument: Applications Manufacturers ................C-1

D Survey Instrument: Device Manufacturers.........................D-1

E Survey Instrument: Software Developers............................E-1

F Completed Interviews ........................................................F-1
vi

Figures

Figure 2-1 Industry Relationships and NIST’s Role in Developing

Simulation Modeling Tools for IGBTs......................................... 2-9

Figure 2-2 Distribution of Harris Corporation Sales by Segment: 1997 ..... 2-13

Figure 2-3 Distribution of International Rectifier Sales by Product:

1997........................................................................................ 2-13

Figure 3-1 The Interaction of Design Activities Among Members of the

Supply Chain............................................................................. 3-3

Figure 3-2 System Design Process Without Simulation Modeling ................ 3-5

Figure 3-3 System Design Process with Simulation Modeling ...................... 3-6

Figure 4-1 Defining Benefits and Costs ....................................................... 4-2

Figure 4-2 Sampling Plan for Surveys........................................................ 4-14
vii

Tables

Table 1-1 Economic Sectors and Related Benefit Categories....................... 1-6

Table 2-1 Projected Applications for IGBTs by the Year 2000 .................... 2-8

Table 2-2 Company-Level Data for Major U.S. Manufacturers of IGBT

Devices ................................................................................... 2-11

Table 2-3 U.S. Automobile Manufacturers and Their Primary Device

Supplier................................................................................... 2-15

Table 2-4 Major U.S. Motor Control Manufacturers ................................. 2-15

Table 2-5 Selected Power Control Manufacturers..................................... 2-16

Table 2-6 U.S. Manufacturers of Compact Fluorescents ........................... 2-17

Table 3-1 Technical Impacts of Simulation Modeling of IGBT Devices....... 3-2

Table 4-1 Metrics for Estimating Economic Benefits ................................. 4-13

Table 5-1 Number of Interviews by Type and Sector.................................. 5-3

Table 5-2 Benefits—IGBT Modeling Cost Reductions for Automotive

Design Application .................................................................... 5-6

Table 5-3 Research Facility-Level Modeling User Costs for the

Automobile Design Application ................................................. 5-7

Table 5-4 Benefits—IGBT Modeling Cost Reductions for Motor

Control Applications (typical research facility)............................ 5-9

Table 5-5 IGBT Modeling User Costs for Motor Control Applications

(typical research facility) ............................................................ 5-9

Table 5-6 Benefits—IGBT Modeling User Cost Reductions for

Additional Applications ........................................................... 5-10

Table 5-7 IGBT Modeling Overhead Costs for Additional Applications..... 5-11

Table 5-8 Benefits for Device Manufacturers............................................ 5-12
viii

Table 5-9 Overhead Costs for Device Manufacturers ............................... 5-12

Table 5-10 Estimated Motor Electricity Usage and Potential ASD

Savings .................................................................................... 5-16

Table 5-11 Economic Sectors and Related Benefit Categories..................... 5-18

Table 5-12 Estimated Benefits and Costs to Industry from Simulation

Modeling of IGBTs in the System Design Process ..................... 5-21

Table 5-13 Net Benefits Generated by Industry—by Industry Group and

Year ($thousand 1998)............................................................. 5-23

Table 5-14a Actual NIST Program (Nominal) Expenditures by Year.............. 5-26

Table 5-14b Inflation Adjusted NIST Program (Real) Expenditures by Year

($thousands 1998) ................................................................... 5-27
ES-1

Executive Summary

The National Institute of Standards and Technology’s Electronic and

Electrical Engineering Laboratory (NIST/EEEL) program supports the

development of mathematical models for several classes of

semiconductor devices. This study presents the results from a

microeconomic impact assessment of the development of

mathematical models for the design of insulated-gate bipolar

transistor (IGBT) semiconductor power devices. NIST/EEEL’s IGBT

mathematical modeling program (referred to as the NIST IGBT

modeling program) has led to significant economic benefits. These

benefits include

Z improvements in R&D efficiency,

Z decreases in transaction costs,

Z decreases in production costs, and

Z improvements in product quality.

NIST’s activities have affected software companies, IGBT device

manufacturers, and manufacturers of products that employ IGBTs

(referred to as applications manufacturers). Software companies

have incorporated NIST’s mathematical models into their

commercial simulation modeling software. Device manufacturers,

such as Harris Semiconductors and International Rectifier, and

applications manufacturers, such as Ford Motor Company and

General Electric, use this software to design electrical systems

employing IGBTs. IGBTs are used in a wide range of applications,

such as automotive ignition systems and adjustable speed drives. In

the absence of NIST’s activities, industry experts stated that the

availability of IGBT simulation modeling software “would have

been delayed, and the modeling software developed would not

have been as accurate.”

NIST’s contributions to the

development of simulation

modeling tools for IGBT

power devices have led to

significant economic

benefits primarily through

increased R&D efficiency

and increased product

quality.
Benefit Analysis of IGBT Power Device Simulation Modeling

ES-2

This study quantifies the economic benefits associated with

improvements in R&D efficiency and reductions in transaction

costs. In addition, the study identifies and qualitatively describes

the impact of the NIST IGBT modeling program on production costs

and quality and performance of final products employing IGBTs.

Table ES-1 presents several measures of social return to NIST’s

investment in mathematical models of IGBTs. A range of social

returns to NIST’s investment is presented, reflecting the difficulties

in quantifying the quality and timing of the development of IGBT

modeling in the absence of NIST’s contributions.

Measure Estimate Range

Benefit-cost ratio 23.2 ±7.7

Social rate of return 76.5% ±9.1%

Net present value ($thousands,

1998)

$9,954 ±3,467

The returns in Table ES-1 are based on the value of improvements

in R&D efficiency, the savings to industry from decreased

transaction costs, and the NIST IGBT modeling program

expenditures. Actual economic impacts associated with NIST’s

contributions are likely to be larger than the estimates presented in

Table ES-1 because they do not include the economic impacts of

reduced production costs and improved product quality. Although

industry experts indicated that manufacturing costs and product

quality benefits do result from using simulation modeling in

designing IGBT systems, they were not able to quantify these

impacts.

ES.1 NIST’S ROLE AND MARKET BARRIERS TO

SOFTWARE DEVELOPMENT

In 1985 NIST’s Electronic and Electrical Engineering Laboratory

(EEEL) program initiated a project to support and promote

semiconductor power-device modeling. One of the main outputs

from the NIST Program was the development of mathematical

models for IGBT devices that simulate their performance. Several

Table ES-1. Measures of

Economic Benefits from

the NIST Program

The benefits of the NIST IGBT

modeling program are at least

15 times the cost.
Executive Summary

ES-3

industry experts and academics stated that NIST’s model is the

“universal standard for IGBT modeling.”

NIST’s mathematical models for IGBT devices were introduced into

commercial simulation software products in 1990. The automotive

industry was one of the first industries to integrate IGBT simulation

modeling into their design process, using it in the design of

electronic ignition systems and electronic vehicles. By late 1990s

these software products were widely used by IGBT device

manufacturers and by applications manufacturers producing motor

control, lighting, power control, and automotive products. Figure

ES-1 illustrates the path through which NIST’s mathematical models

have affected industry and end users of products employing IGBT

devices.

The development and verification of IGBT simulation modeling

software currently used by industry resulted from the combined

efforts of NIST, software companies, and device and applications

manufacturers. For example, Ford Motor Company and its device

supplier Motorola made important contributions to verifying and

incorporating NIST’s mathematical models into Analogy’s software

product SABER. In the process they generated significant

technology spillovers by making IGBT simulation tools available to

other applications manufacturers, such as manufacturers of motor

controls or power control equipment.

Industry experts indicated that NIST had a “significant” impact on

the development and use of IGBT simulation modeling tools. The

general consensus was that software for IGBT simulation modeling

may have been developed in the absence of NIST’s efforts;

however, industry experts acknowledge that NIST’s efforts in

developing and promoting the use of simulation modeling of IGBTs

have

Z increased the accuracy of simulation models for IGBTs used

in software products, such as SABER and PSPICE;

Z accelerated the adoption of simulation models and virtual

prototyping by system designers and device manufacturers;

and

Z lowered the cost of software development for simulation

software companies such as Analogy and Orcad.

NIST’s mathematical

models for IGBT

devices were

introduced into

commercial

simulation software

products in 1990.
Benefit Analysis of IGBT Power Device Simulation Modeling

ES-4

Figure ES-1. Industry Relationships and NIST’s Role in Developing Simulation Modeling Tools

for IGBTs

NIST collaborated with members of the semiconductor industry supply chain to develop and verify IGBT simulation

modeling software.

NIST Program

Device

Manufacturers

Applications

Manufacturers

End Users

Final

Products

Simulation Models

Simulation

Software

Model

Verification

Model

Verification

Mathematical

Modeling of

IGBTs

Software Companies

Market barriers contributed to the delay in the development of

IGBT capabilities in simulation modeling software. Two of the

main barriers are the following:

Z Software companies do not have the technology base to

develop, verify, and implement the required mathematical

algorithms.

Z Applications manufacturers that have the required technical

expertise are not able to appropriate the returns to these

R&D activities.

NIST’s role in the development and incorporation of IGBT

modeling capabilities into software products such as SABER was

motivated by these market barriers.
Executive Summary

ES-5

ES.2 IMPACT CATEGORIES AND ANALYSIS

RESULTS

The net present value (NPV) of the NIST program expenditures

related to the development and promotion of simulation modeling

for IGBT power devices is presented in Table ES-2. Program

expenditures began in 1985 and are projected to continue through

the year 2000 at current expenditure levels (Hefner, 1998). Labor

costs account for the largest share of program costs.

Categories

Expenditures

NPV (thousands, $1998)

Labor 363.4

Equipment 61.1

Miscellaneous costs 22.5

Total 477.0

As shown in Figure ES-1, NIST’s contributions to the development

of simulation modeling tools have generated benefits for several

sectors of the economy, including software companies, device

manufacturers, applications manufacturers, and end users of

products employing IGBT devices. Table ES-3 relates benefit

categories with associated economic sectors.

Table ES-3. Economic Sectors and Related Benefit Categories

NIST’s IGBT modeling program generated different benefits to each member of the supply chain.

Sectors

R&D

Efficiency

Transaction

Costs

Production

Costs

Product

Quality

Software companies X

Device manufacturers X

Applications manufacturers X XX

End users X

Table ES-2. NIST

Program Expenditures

The NPV of NIST’s IGBT

program expenditures from

1985 to 2000 is $477,000.
Benefit Analysis of IGBT Power Device Simulation Modeling

ES-6

Software companies benefited from the development of NIST’s

mathematical models of IGBT performance and from NIST’s model

verification activities with applications and device manufacturers.

These activities lowered the R&D costs for incorporating IGBT

simulation modeling capabilities into their software products.

Device manufacturers use NIST’s models to develop product

datasheets for the IGBT devices they manufacture. The datasheets

provide performance information to applications manufacturers and

support the comparison of competing IGBT devices. The use of

NIST’s model for developing datasheets reduces transaction costs

by increasing the quantity and quality of information available to

applications manufacturers and by lowering the cost for device

manufacturers to generate the information.

Applications manufacturers use simulation software incorporating

NIST’s model in the design of electrical systems employing IGBTs.

Simulation models are used to develop virtual prototypes that

reduce the R&D cycle design time, lower labor cost, and reduce

material costs associated with developing physical prototypes.

The end users of products that employ IGBTs benefit from NIST’s

models because their use in the systems design process also

increases the quality of final products employing IGBTs. For

example, the use of simulation modeling for designing ignition

switches increased the fuel efficiency of automobiles, and the use

of simulation modeling for designing adjustable speed drives (ASDs)

decreased energy consumption of electric motors. The potential

benefits to society from increased product quality are very large.

The quantitative analysis of the economic benefits from the NIST

IGBT modeling program focused on changes in R&D efficiency for

applications manufacturers and transaction costs for device

manufacturers. Table ES-4 presents the NPV of benefits to these

industry sectors in 1998 dollars. The table includes aggregated

benefits from 1990 to 2003. The design of motor controls, such as

ASDs account for 63 percent of quantified benefits.

The quantitative analysis does not include benefits due to reduced

production costs and improved product quality. However, we did

conduct a qualitative analysis of these benefit categories. All of the

modeling and design engineers interviewed said that simulation

modeling leads to improved performance of the final product

The quantitative

analysis of the

economic benefits

from the NIST IGBT

modeling program

focused on changes

in R&D efficiency

for applications

manufacturers and

transaction costs for

device

manufacturers.
Executive Summary

ES-7

Table ES-4. The NPV to Industry of Quantified Benefits from Simulation Modeling of IGBTs

(thousands, $1998)

These benefits include projected benefits through the year 2003 and are presented in 1998 dollars.

Industry Segment R&D Efficiency Transaction Costs

Quantified

Benefits

Device manufacturers 1,301 1,301

Applications manufacturers 

Automotive ignition systems 1,547 1,547

Automotive electric vehicles 588 588

Motor controls 10,859 10,859

Lighting 363 363

Power control 8,673 2,675

Sum 16,033 1,301 17,334

employing the IGBT device. However, no one was able to provide

an accurate estimate of the magnitude of these impacts. In

addition, most contacts said that the use of simulation modeling

leads to material savings in the production process. However, they

could not quantify these savings either.

In several instances, we assessed the potential magnitude of

benefits associated with product quality improvements by

developing example product improvement scenarios. For example,

industry experts indicated that simulation modeling of IGBTs could

increase the efficiency of automobile ignition systems, potentially

leading to a 0.05 percent increase in automobile fuel efficiency.

Based on current automobile fuel consumption, a 0.05 percent

increase in fuel efficiency would decrease fuel expenditures by

$33.5 million per year.

ES.3 FUTURE TRENDS AND BARRIERS TO

ADOPTION

The use of IGBT simulation modeling is still gaining momentum

and will continue to expand into new product areas. Many

applications manufacturers are in the process of adopting IGBT

simulation modeling, and the benefits will be realized in the near

future. Future penetration of IGBT simulation modeling will be
Benefit Analysis of IGBT Power Device Simulation Modeling

ES-8

driven by factors such as the increasing complexity of electrical

systems and the spread of IGBTs into lower voltage applications.

All industry experts interviewed as part of this study acknowledged

the “potential” benefits associated with simulation modeling of

IGBTs in the design process; however, they also indicated that

certain factors are limiting widespread adoption of IGBT simulation

modeling. The most commonly mentioned barriers to the adoption

of IGBT simulation modeling were

Z overhead costs associated with purchasing and maintaining

software and staff training,

Z effort and expense required to characterize IGBT models,

Z modeling limitations and related costs associated with

confidential information,

Z weak models for non-IGBT components, and

Z missing complementary analysis capabilities in simulation

software.

Future activities NIST may want to consider to promote the

adoption of IGBT simulation modeling and enhance its benefits are

Z identifying weak links in the simulation modeling chain and

supporting model development,

Z supporting a standardized modeling language,

Z supporting development of capabilities to model the

distribution of failures resulting from variability in parts, and

Z enhancing systems for patenting semiconductor device

characteristics.
1-1

1 Introduction

The field of power electronics has experienced substantial growth

in recent years due to the introduction of and improvements in

controllable switches. Controllable switches can significantly

enhance the performance of products because they have the

capability to sense voltages, currents, and temperatures and to

provide functions such as load diagnostics and short-circuit

protection. Insulated-gate bipolar transistors (IGBT) semiconductor

devices are the dominant controllable switches for devices ranging

from 200 to 1,500 volts.

The increased performance requirements and general technical

sophistication of end products employing IGBTs have led to the

need for advanced modeling tools to support the custom design of

IGBT power devices. However, the technical infrastructure

necessary to support custom design of IGBTs systems has not

developed as rapidly as the demand for products using IGBTs. In

particular, the development and commercialization of

mathematical models of IGBTs have been slow because of the

infrastructure-type market failures associated with design tools.

The National Institute of Standards and Technology (NIST) provides

measurement infrastructure support to U.S.-based industries for the

purpose of promoting economic growth. The broad, economywide portfolio of technologies for which these infratechnologies are

provided creates a demanding strategic planning challenge for

NIST. In response, NIST requires economic assessments of

technologies, industries, and market structure to
Benefit Analysis of IGBT Power Device Simulation Modeling

1-2

Z project or document the returns from NIST’s laboratory

research programs and

Z provide information that NIST can use to improve the

selection and management of its portfolio of projects.

This project furthers NIST’s objectives for economic analysis by

examining NIST’s contributions to the mathematical modeling of

IGBT power devices. Mathematical modeling of IGBTs (also

referred to as simulation modeling) allows designers to use “virtual”

prototypes when designing electrical systems that incorporate IGBT

power devices. In the past, IGBT system designs relied primarily on

constructing physical test circuitry and failing (destroying) the

circuitry to analyze extreme conditions. In comparison, using

mathematical modeling to develop virtual prototypes is faster and

less expensive and leads to superior designs.

This section introduces the project by outlining its objectives,

discussing the motivation for NIST’s involvement, summarizing

NIST’s contributions to the development of IGBT mathematical

models and software tools, and presenting an overview of the

analysis approach. Section 2 provides background information on

IGBT power devices, product applications, and manufacturers in

the supply chain. Sections 3 and 4 describe the technical impacts

associated with using simulation modeling of IGBTs in the system

design process and our methodology for estimating economic

impacts. Analysis results are presented in Section 5, and market

barriers to the development and adoption of IGBT simulation

modeling are discussed in Section 6 along with potential future

roles for NIST.

1.1 PROJECT OBJECTIVES

The objective of this project was to conduct a microeconomic

impact assessment of NIST’s contributions to mathematical

modeling of IGBT power devices. The focus of the analysis was to

evaluate the social benefits from incorporating NIST’s mathematical

modeling capabilities for IGBTs into commercially available

simulation software products. The analysis included

Z a quantitative analysis of the impact of IGBT simulation

modeling on applications manufacturers’ R&D efficiency

and on device manufacturers’ transactions costs and,

This project furthers

NIST’s objectives for

economic analysis

by examining NIST’s

contributions to the

mathematical

modeling of

insulated-gate

bipolar transistor

(IGBT) power

devices.
Section 1 — Introduction

1-3

Z a qualitative analysis of IGBT simulation

modeling’s impact on changes in production

costs and on increased product quality and

performance of final products employing IGBT

devices.

This study includes both retrospective and prospective

analyses of NIST’s contributions to date on existing

products employing IGBTs. In addition, we identify

NIST’s impact on future products employing IGBTs, such

as electric cars and advanced medical applications.

1.2 MOTIVATION FOR NIST’S INVOLVEMENT

The potential benefits to society from the use of simulation

modeling in the design of products employing IGBT power devices

are large. Industry benefits from increased R&D efficiency, reduced

transaction costs, and decreased production costs. Consumers

benefit from increased product quality at decreased prices. In

addition, environment benefits are generated from the increased

energy efficiency of products employing IGBTs.

The versatility of IGBT devices places increased demand on

designers to modify devices to meet the specific technical

requirements of each new application. The technical infrastructure

necessary to support efficient custom design includes technology

tools such as

Z mathematical models, test methods, and standards for

simulating device performance;

Z component libraries containing scientific and engineering

data that specify design parameters; and

Z model verification parameters and techniques to provide

measurements, comparisons, and test circuits for verifying

that device models are performing properly.

These tools have infratechnology characteristics because they

improve the efficiency of R&D and advance industry’s

technological opportunities. Mathematical models, test methods,

and standards allow researchers to build on previous work using

terminology and measurements common to their colleagues. In

addition, the replication and verification of research results are

essential to building component libraries and to verifying models.

These infratechnologies in the semiconductor power-device

industry also enhance the efficiency of the production process and

The focus of the analysis was

to evaluate the social benefits

from incorporating NIST’s

mathematical modeling

capabilities for IGBTs into

commercially available

simulation software products.
Benefit Analysis of IGBT Power Device Simulation Modeling

1-4

the characteristics of products by providing tools for quality

assurance and process control.

Because modeling capabilities possess many of the characteristics

of public goods, social returns on investments in infratechnologies,

such as mathematical modeling, are often greater than private

returns. In the instances where private returns are not large enough

to stimulate investment (i.e., the private return is not greater than

industries’ hurdle rate of return), this leads to a market failure and

underinvestment by the private sector.1

1.3 NIST’S CONTRIBUTIONS TO MATHEMATICAL

MODELING OF IGBT POWER DEVICES

In 1985 NIST’s Electronic and Electrical Engineering Laboratory

(EEEL) program initiated a project to support and promote IGBT

semiconductor power-device modeling (referred to as the NIST

IGBT modeling program). Dr. Allen Hefner at NIST is the project

manager and the principal scientist. To date, NIST’s contributions

in the field of IGBT power-device modeling have led to advances in

Z mathematical modeling,

Z device design,

Z model parameter extraction,

Z circuit utilization, and

Z model validation.

Mathematical modeling, model parameter extraction, and model

validation are all infratechnologies that stimulate R&D, improve the

efficiency of R&D, advance industry’s technological opportunities,

and promote technology adoption. The term “simulation

modeling” is used to refer to this group of design activities.

NIST’s core contribution has been the development of a physicsbased mathematical model (commonly referred to as the NIST

model or as Dr. Hefner’s model) that accurately predicts behavioral

parameters of IGBT power devices. The academic community

recognizes Dr. Hefner’s model as a “significant professional

 1Nelson (1959) and Arrow (1962) provided the earliest and most influential

discussions of market failure in the production of knowledge. Many authors

have clarified this view, and Tassey (1997) has discussed market failure in the

context of infratechnologies.

The NIST model is

internationally

accepted as the

standard by which

other IGBT models

are compared.
Section 1 — Introduction

1-5

contribution.” The model is internationally accepted as the

standard to which other IGBT models are compared.

NIST has collaborated with Analogy, Inc., to incorporate Hefner’s

Model into Analogy’s design software SABER. Components of

Hefner’s Model have also been incorporated into other simulation

models such as OrCad’s software PSPICE. Industry experts

acknowledge that NIST’s efforts in developing and promoting the

use of simulation modeling of IGBTs have

Z increased the accuracy of simulation models for IGBTs used

in software products, such as SABER and PSPICE;

Z accelerated the adoption of simulation models and virtual

prototyping by system designers and device manufacturers;

and

Z lowered the cost of software development for simulation

software companies such as Analogy and Orcad.

Several contacts from device manufacturers and applications

manufacturers stated that NIST has had a “significant” impact on

the development and use of simulation modeling using

mathematical models. The general consensus is that software for

simulation modeling would have been developed in the absence of

NIST’s efforts. However, the models would not have been as

accurate and hence would not have penetrated the market as

quickly as the products using NIST’s mathematical models.

NIST’s contribution to infratechnologies has also leveraged related

private-sector investment. Software companies that develop, refine,

or market device models and component libraries build on NIST’s

contributions to mathematical modeling. Device manufacturers

and applications manufacturers use NIST technology to simulate

IGBT device performance and thus can provide higherquality/lower-cost devices and system designs.

1.4 OVERVIEW OF ANALYSIS APPROACH

Our approach to estimating the economic impact of NIST’s

contribution to IGBT semiconductor power-device modeling

required two main steps:

Z Identifying the impacts associated with the simulation

modeling of IGBTs. This step included estimating benefits

associated with currently affected markets and projecting

NIST has had a

“significant” impact

on the development

and use of

simulation modeling

using mathematical

models.
Benefit Analysis of IGBT Power Device Simulation Modeling

1-6

potential impacts of existing modeling capabilities into the

near future.

Z Assessing NIST’s impact on developing and adopting

simulation modeling of IGBTs. NIST’s contribution to social

welfare is a portion of the total net benefit to society from

simulation modeling of IGBTs.

Sectors affected by the use of simulation modeling are software

companies, device manufacturers, applications manufacturers, and

end users of products employing IGBT devices. Table 1-1 relates

benefit categories with associated economic sectors.

Table 1-1. Economic Sectors and Related Benefit Categories

The categories identified with an X were included in the quantitative analysis. The categories identified with a X were

evaluated qualitatively.

Sectors

R&D

Efficiency

Transaction

Costs

Production

Costs

Product

Quality

Software companies X

Device manufacturers X

Applications manufacturers X X X

End users X

As shown in Table 1-1, the analysis quantifies the value of the

impacts associated with changes in applications manufacturers’

R&D efficiency and device manufacturers’ transaction costs. The

remaining economic sectors and benefit categories were evaluated

qualitatively.2

 2For the categories evaluated qualitatively, technical and economic benefits

associated with simulation modeling of IGBTs were identified, but industry

contacts could not reliably quantify the magnitude of the benefits.
2-1

The IGBT Supply 2 Chain

IGBT power devices are controllable switches and are used in a

wide range of products for motor and power control. IGBTs

currently dominate the medium- to high-voltage applications

markets, devices ranging from 200 to 1,500 volts. However, as

technology advances decrease the cost of IGBTs, they are expected

to penetrate the market for low-voltage controllable switches, such

as household appliances.

This section provides background information on IGBT power

devices and their current and future applications in final products.

We then describe the three major segments of the IGBT simulation

modeling supply chain: software companies, device

manufacturers, and application manufacturers.

2.1 IGBT POWER DEVICES

The IGBT is a hybrid of two transistors: the bipolar transistor and

the metal-oxide-semiconductor field effect transistor (MOSFET).

The technical advantages from joining these two devices are

threefold:

Z First, the IGBT’s MOSFET is typically controlled by 10 volts,

but the whole unit can control nearly 1,500 volts and

100 amperes.

Z Second, the IGBT has a higher operating current density

than its components.

Z Third, when switched on, the IGBT has very low electrical

resistance between the collector and the emitter (Baliga,

1997).
Benefit Analysis of IGBT Power Device Simulation Modeling

2-2

These three attributes allow IGBTs to be smaller, more efficient,

and less expensive to produce compared to alternative controllable

switches in their voltage range, such as the Darlington transistor.

The smoother sine wave keeps the motors controlled by the IGBT

from generating excessive harmonics. Harmonics create heat and

waste energy and can also lead to significant damage to the device

and power quality problems. In addition, the IGBT’s high

switching frequencies exceed humans’ detection range, making the

applications employing IGBTs quieter and more suitable for

commercial and household applications.

MOSFETs are currently used for lower voltage controllable switch

applications. MOSFETs are less expensive than IGBTs and can be

switched on and off at incredibly high speeds. The main limitation

of MOSFETs is their inability to handle high voltages. MOSFETs

lose their ability to efficiently control power at voltages of 100 volts

or greater.

Appendix A contains a brief history of the development of

semiconductor power devices and a more detailed description of

the technical characteristics of IGBTs.

2.2 END-USE APPLICATIONS

End-use applications for IGBTs are concentrated in the automotive,

motor control, power control, and lighting markets. The use of

IGBTs is anticipated to expand rapidly in the future as the cost of

manufacturing them decreases and environmental concerns place

efficient power control systems high on the list of priorities for

manufacturers and regulators (Baliga, 1997).

2.2.1 Automotive Applications

Automotive applications of IGBTs are currently limited to ignition

systems and motor controllers in electric vehicles. These

applications are ideal for IGBT devices because they require highvoltage switching capabilities. The remaining electronic systems in

automobiles requiring power devices, such as power accessories

and fuel injection systems, use standard 12 volt systems and are

more efficiently controlled by power MOSFETs.

The smoother sine

wave keeps the

motors controlled

by the IGBT from

generating excessive

harmonics.

Harmonics create

heat and waste

energy and can also

lead to significant

damage to the

device and power

quality problems.

IGBTs are used in

automobiles for ignition

systems and motor

controllers in electric

vehicles.
Section 2 — The IGBT Supply Chain

2-3

Ignition Systems

Ignition systems ignite the air/fuel combination that powers engines

in motor vehicles. In the 1970s, electronic (or distributorless)

ignition systems were developed that would eventually replace the

50-year old Kettering breaker-point ignition system, which had used

a distributor along with manifolds and valves to control spark

timing. The advantages of electronic ignition systems include

Z reduced emissions,

Z increased fuel efficiency, and

Z increased reliability

All American and European automobile manufacturers had

introduced electronic ignition systems by the early 1990s. Japanese

auto makers introduced electronic ignition systems in the 1995

model year.

Originally, electronic ignitions were controlled by devices known

as Darlington transistors, but those transistors were replaced by

IGBTs beginning in 1992. The Darlington transistor controlled

spark timing but needed a high drive current, sapping power in the

driver integrated circuit (IC). IGBTs improved ignition designs by

reducing the number of protective devices required, simplifying the

controlling circuit, and allowing the IGBT to be driven directly from

a low current microprocessor output port.

IGBTs’ seemingly late adoption by the automotive industry was

because of device-design issues that made IGBTs unsuitable for

automotive applications. Semiconductor manufacturers had

experimented with automotive IGBTs since the early 1980s, but

IGBTs’ high saturation voltage (more than 2 volts) and need for high

gate potential (more than 12 volts) prevented them from being used.

By 1990, researchers resolved these problems. Designers

optimized the current gain of the device’s structure, which reduced

the saturation voltage to acceptable levels. To drop the gate

potential from 12 to below 2 volts, designers used a thinner oxide

layer. Currently, a second generation of ignition IGBTs is being

designed that meets ignition system requirements while using 40

percent less silicon than the previous generation of IGBTs (Mamileti

et al., 1996).
Benefit Analysis of IGBT Power Device Simulation Modeling

2-4

Electric Vehicles

Electric vehicles have been introduced as an environmentally

responsible alternative to traditional vehicles that consume fossil

fuels. General Motors, among other manufacturers, began

producing electric vehicles for niche markets, such as California

and Arizona, where air quality is a pressing concern. In addition,

numerous manufacturers are experimenting with hybrid gasoline

and electric automobiles, but none are currently commercially

available.

IGBT-based systems are used in the power control modules of

electric vehicles to turn energy from fuel cells and batteries into

alternating current (AC) to drive the engine. When the vehicle

operator presses or eases off the accelerator to vary speed, a signal

is sent to the power control module, or controller. The controller

monitors and directs a number of power modules containing an

array of IGBTs that distribute the battery voltage and current to the

motor in amounts proportional to the pressure applied to the

accelerator. In this way the IGBTs control the flow of electricity

from the batteries to the motor. They also switch the electricity

from the batteries’ direct current (DC) to the AC the motor uses.

General Motors’ EV1 contains six arrays of six IGBTs (for a total of

36) that distribute power to the motor.

Electric automobiles’ market penetration has been limited because

their lead-acid battery packs can go no farther than 100 miles per

charge. However, new technologies such as nickel-metal-hydride

packs will allow electric automobiles to travel much farther than

100 miles per charge. A recent prototype pack allowed an electric

car to travel 375 miles on one charge. The prototype pack

contained batteries that cost over $35,000; however, it is estimated

that the pack’s cost will drop to $5,000 and last for 100,000 miles

(Electric Auto Association, 1998).

2.2.2 Motor Controls

IGBTs are the key component of adjustable speed drives (ASDs) that

enable motor controls to vary output speed. ASDs make more

efficient use of electricity by providing only the necessary amount

of power to accomplish a task. ASDs also provide more accurate

control of precision equipment such as robotic machinery and x-ray

machines.

IGBT-based systems

are used in the

power control

modules of electric

vehicles to turn

energy from fuel

cells and batteries

into alternating

current (AC) to drive

the engine.
Section 2 — The IGBT Supply Chain

2-5

IGBTs provide the ability to regulate input current more precisely

than their predecessors. During the early to mid-1990s ASD

manufacturers migrated from bipolar junction transistor (BJT)

semiconductors to IGBTs as the preferred output switching device

(Skibinski, Maslowski, and Pankau, 1997). The technical advantage

of IGBTs over BJTs is that device rise and fall time switching

capability is five to ten times faster. Faster switching time generates

smoother sine waves, leading to more efficient and precise drive

control.

Industrial motors are commonly outfitted with ASDs to provide

speed control for a variety of factory machinery, equipment, and

robotic systems. ASDs in industrial motors reduce electricity

consumption by varying output power. Motors with ASDs are

significantly more energy efficient than constant speed motors for

applications that operate a large portion of the time at partial loads.

One of the largest applications of ASDs is heating, ventilation, and

air conditioning (HVAC) systems. ASDs enable air ventilation

systems to run more efficiently at part loads. For example, an air

conditioning unit traditionally had one speed, “on.” The

compressor ran at full power to cool a room. With an ASD

controlling the fan, the system can run continuously at 25 percent

as opposed to off and on at 100 percent. Running at part load

reduces the amount of energy needed to meet the same cooling

requirements.

2.2.3 Power Control Equipment

Power control is a broad applications category that includes power

conditioning, power correction, and industrial electrotechnologies.

IGBT-based systems are used to “clean” and regulate power flows

for these applications.

Power conditioners primarily regulate voltage surges and

overvoltage and brownouts and handle isolation problems such as

noise and grounding issues. Fluctuations in voltage are typically

caused by severe weather, such as lightning, and generator or

transmission faults and can lead to damaged equipment, false or

lost data, and data transmission disruptions.

IGBTs provide adjustable

speed drives the ability to

regulate input current more

precisely than their

predecessors.
Benefit Analysis of IGBT Power Device Simulation Modeling

2-6

IGBTs are used in power factor correction equipment to switch

banks of capacitors on- and off-line to maintain a high power

factor. The high-speed switching capabilities of IGBTs increase the

efficiency of the equipment and reduce the capacitor and resistor

component costs required to meet a specific level of performance

(power factor improvement).

Power factor correction equipment is used to improve power

factors at large industrial plants by regulating reactive power.1 A

power factor is the ratio of active power to total power and

quantifies the portion of power used by a facility that does

electrically useful work. A power factor of 90 percent implies that

10 percent of the total power is being lost. Large contributors to

poor power factors are motors operating at part load and motors

with frequent start-up and shut-down schedules.

Power companies generally charge an additional fee to facilities

having power factors less than 85 to 95 percent to capture

generating costs not reflected in their electric energy (kWh) meter.

Additional benefits from power factors close to 100 percent are

better voltage regulation and released system capacity.

IGBTs are also used in industrial electrotechnolgies, such as high

frequency welding, electroplating, and induction heating. For

example, the availability of IGBTs has resulted in the development

of high-frequency (>20 kHz) welding power supplies. IGBT’s

increased switching frequency leads to the following benefits:

Z reduced size and weight, and hence cost;

Z improved welding performance; and

Z reduced noise (Theron et al., 1993).

Additional high-voltage supply applications that use IGBTs include

highly specialized equipment for military and public utility

applications. Examples of these applications are electrical power

distribution and transmission equipment and locomotive drives for

electric trains.

 1Inductive devices, such as inductive motors, magnetic ballasts, and transformers

require two types of power to operate—active and reactive power. Active

power (also called real power) produces work or heat and is expressed in terms

of kilowatts (kW). Reactive power does not perform useful work but is used by

inductive devices to generate magnetic fields. Reactive power is expressed in

terms of kilovolt-amps (kVARs). Total power (also referred to as apparent

power) is the vector sum of active and reactive power.

The high speed switching

capability of IGBTs

increases the efficiency of

power correction

equipment and reduces the

capacitor and resistor

component costs.
Section 2 — The IGBT Supply Chain

2-7

2.2.4 Lighting

IGBTs and power MOSFETs are used in electronic lamp ballasts to

control current for lighting applications. Electronic lamp ballasts

(ELBs) that incorporate power semiconductors provide a variety of

benefits. First, they are more energy efficient. Second, they reduce

the amount of harmonics sent back on the wire, improving overall

power quality for the commercial or industrial facility. Finally, they

eliminate the stroboscopic effect, or flicker, associated with

fluorescent lighting.

Currently IGBTs are used primarily in the electronic lamp ballasts

of compact fluorescent lights. However, it is anticipated that in the

near future IGBTs will penetrate the larger market of electronic

ballasts for fluorescent lamps used in commercial buildings.

2.2.5 Future Trends and Applications

The growth in IGBT usage in the medium-power control market is

expected to continue; no substitute products are anticipated in the

foreseeable future. The IGBT currently dominates the market for

medium-power control devices between 200 and 1,500 volts. In

the near future IGBTs are expected to make inroads in the lowervoltage power-device applications, replacing power MOSFETs

(Baliga, 1998).

For large power control devices (greater than 3,000 volts), the

thyristor continues to be the dominant device. Thyristors are

capable of controlling high voltage levels on the order of 6,000

volts or more and can carry 1,000 amperes. Even though they are

relatively small devices, they require huge control circuits, have

slower switching capabilities, and are much noisier. Some

Japanese corporations are experimenting with high-voltage

applications using groups of IGBTs.

Table 2-1 presents future applications for IGBTs. Automobile

electronics are projected to be the largest user of IGBTs in the near

future.

Twenty to 30 percent of the

electricity consumed in the

U.S. is for lighting

purposes. By expanding

the use of electronic

ballasts that incorporate

IGBTs in lighting, experts

estimate that energy

consumption for lighting

could be reduced by onethird (Jednacz, 1991a).
Benefit Analysis of IGBT Power Device Simulation Modeling

2-8

Application Projected Market

Display drives $2 billion

Computer power supplies $3 billion

Adjustable speed drives $1 billion

Factory automation $1 billion

Telecommunications $5 billion

Appliance controls $3 billion

Consumer electronics $2 billion

Lighting ballasts $3 billion

Smart homes $5 billion

Air-craft electronics $5 billion

Automobile electronics $10 billion

Source: Baliga, Jayant. 1997. “How the Super-transistor Works.” Scientific

American 8(1):34-41.

IGBTs are just beginning to be used in household applications, and

this market is expected to be a significant growth area for the use of

IGBTs. In the average household in a developed country, there are

40 electric motors in everything from blenders to compressors

(Baliga, 1997). The number of those devices controlled by IGBTs

will increase as their usage spreads into smaller devices. For

example, Maytag has recently introduced ASDs incorporating

IGBTs produced by Emerson Electronics into their top-of-the-line

washing machines. High-end refrigerators are also being fitted with

ASDs incorporating IGBTs. In addition to the advantage of reduced

energy consumption, the IGBTs enable silent compressors,

eliminating background noise (hum) because their switching speeds

generate pulses that have a frequency range that is above human

hearing.

2.3 IGBT SIMULATION MODELING SUPPLY

CHAIN

The IGBT simulation modeling supply chain is shown in Figure 2-1

and includes software companies, device manufacturers, and

applications manufacturers. Software companies supply simulation

tools to both device and applications manufacturers. Device and

Table 2-1. Projected

Applications for IGBTs by

the Year 2000

Automobile electronics,

telecommunications, and smart

homes are projected to be the

largest users of IGBTs in the

near future.
Section 2 — The IGBT Supply Chain

2-9

applications manufacturers use the simulation tools to integrate

IGBT devices in electrical systems. Device and applications

manufacturers typically work closely together in an iterative

process during the electrical system design.

As shown in Figure 2-1 there is significant feedback from device

and applications manufacturers to support the development and

verification of mathematical algorithms. NIST has played a leading

role in coordinating this feedback to support the development and

verification of mathematical models for IGBTs. This subsection

discusses the major companies involved in the IGBT simulation

modeling supply chain.

Figure 2-1. Industry Relationships and NIST’s Role in Developing Simulation Modeling Tools

for IGBTs

Mathematical modeling of IGBT devices involves many members of the supply chain.

NIST Program

Device

Manufacturers

Applications

Manufacturers

End Users

Final

Products

Simulation Models

Simulation

Software

Model

Verification

Model

Verification

Mathematical

Modeling of

IGBTs

Software Companies
Benefit Analysis of IGBT Power Device Simulation Modeling

2-10

2.3.1 Software Companies

Analogy, Inc., and OrCAD, Inc., are the two major manufacturers

in the U.S. producing modeling software for power electronics

applications. Analogy produces SABER and OrCAD produces

PSPICE (originally developed by MicroSim). These two companies’

software products support virtually all the simulation modeling of

IGBTs (Benjakowski, 1997). The only known foreign competitor

that produces IGBT modeling software is the University of Zurich,

Switzerland; several European companies use this software for IGBT

design (Clemente, 1997).

Analogy, Inc., is a relatively small company in terms of sales and

employment and specializes in software development and support

of simulation modeling of electrical devices and systems. As of

March 1997, the company reported $25.8 million in revenue and

218 employees (Analogy, 1998). Analogy worked directly with

NIST to include Hefner’s mathematical models in SABER. By 1991,

IGBT modeling was available in SABER. SABER is generally viewed

by device and applications manufacturers as the most accurate

modeling tool available. However, it is also more costly and

technologically demanding to use compared to alternative models

such as PSPICE (Benjakowski, 1997).

MicroSim incorporated NIST’s mathematical modeling algorithms

in its software product PSPICE in the early 1990s. The NIST IGBT

Model was integrated into PSPICE through the combined efforts of

MicroSim, NIST, SRC, and the University of Florida (Shen, 1997).

MicroSim merged with OrCAD in 1997. OrCAD is a leading

supplier of electronic design automation (EDA) software and

services to engineering firms developing products on the

Intel/Microsoft platform (OrCAD, 1998). In 1997, OrCAD

(including MicroSim) had revenues of $44 million.

2.3.2 Device Manufacturers

U.S. device manufacturers have focused on IGBT devices with

current capacities from 10 to 50 amperes. These devices employ a

single silicon chip. Table 2-2 provides information on the major

U.S. manufacturers of IGBT devices. Of these companies,

Analogy worked

directly with NIST to

include Hefner’s

mathematical

models in SABER.

By 1991, IGBT

modeling was

available in SABER.
Section 2 — The IGBT Supply Chain

2-11

Table 2-2. Company-Level Data for Major U.S. Manufacturers of IGBT Devices

Delco Electronics, Harris Corporation, International Rectifier, and Motorola use SABER for IGBT modeling.

Name

Parent

Company

Organization TypeSalesa

($million) Employment

Fiscal

Year

Ended End-Use Applications

Advanced

Power

Technology

— NA NA NA NA Automotive electronics,

consumer audio systems,

factory automation,

computers and

telecommunications

uninteruptible power

supplies, sonar and radar

systems

Delphi

Delco

Electronics

Delphi

Automotive

Systems

Public

Subsidiary

$5,560 31,000 12/31/95 Automotive electronics

for General Motors

automobiles

Harris

Semiconductor

Harris

Corporation

Public

Subsidiary

$637 8,489 06/30/95 Motor controllers and

power supplies,

automotive electronic

systems, communications

systems, military and

aerospace applications

International

Rectifier

— Public $486 4,385 06/30/97 Automobile electronic

systems, computer

applications, consumer

electronics, lighting

applications, industrial

applications, government

and aerospace

applications

IXYS

Corporation

__ Private $55 NA 03/31/97 Automotive, industrial,

and power conversion

applications

Motorola

Incorporated

— Public $27,973 139,000 12/31/95 Communications,

automotive, industrial,

consumer electronics

and computer

applications

NA = Not available.

a

Sales include all products, including non-IGBT products.

Sources: Information Access Corporation. 1998. Business Index [computer file]. Foster City, CA: Information Access

Corporation.

Advanced Power Technology (APT). World Wide Web Site:

<http://www.advancedpower.com/Co_Over/BackeG_96.html. Last updated December 16, 1996.

General Motors Corporation. March 20, 1997. 10-K for year ended December 31, 1996. EDGAR Database:

<http://www.edgar-online.com/pointcast/gdoc/?choice=2-616283&nad=0>. Bethesda, MD: Lexis/Nexis.

Harris Corporation. August 29, 1997. 10-K405 for year ended June 27, 1997. EDGAR Database:

<http://www.sec.gov/Archives/edgar/ data/202058/0000950152-97-006326.txt>. Bethesda, MD: Lexis/Nexis.

International Rectifier Corporation. September 26, 1997. 10-K405 for year ended June 30, 1997. EDGAR Database:

<http://www.sec.gov/ Archives/edgar/data/316793/0000912057-97-031847.txt>. Bethesda, MD: Lexis/Nexis.

Motorola Incorporated. March 31, 1997. 10-K/A for year ended December 31, 1996. EDGAR Database:

<http://www.sec.gov/ Archives/edgar/data/68505/0000950131-97-003500.txt>. Bethesda, MD: Lexis/Nexis.
Benefit Analysis of IGBT Power Device Simulation Modeling

2-12

Delphi Delco Electronics, Harris Corporation, International

Rectifier, and Motorola Incorporated hold SABER licenses.

Delphi Delco Electronics manufactures IGBT devices that are used

in the electrical systems of GM automobiles. Delco’s power

MOSFET and IGBT devices are included in GM automobile systems

such as ignition systems, antilock brakes and traction controllers,

air bag deployment, and audio and security systems.

Harris Semiconductor, a subsidiary of Harris Corporation, produces

custom integrated circuits (ICs) and discrete devices that are used in

a variety of products such as automotive systems, wireless

communications, telecommunications, video and imaging systems,

multimedia, industrial equipment, computer peripherals, and

military and aerospace systems. As shown in Figure 2-2,

semiconductor sales accounted for 17.9 percent of Harris

Corporation’s total revenues in 1997 (Harris, 1997). Harris

Corporation’s communications segment (24.9 percent), office

equipment segment (30.9 percent), and electronics segment

(26.3 percent) accounted for the majority of the company’s

revenues. The Harris Corporation is vertically integrated to the

extent that its communications equipment, office business

equipment, and electronic systems incorporate IGBTs and other

semiconductors produced by Harris Semiconductor.

International Rectifier is a worldwide supplier of power

semiconductors and a leader in the power MOSFET segment. The

company’s devices are incorporated in subsystems and end

products manufactured by companies that are not part of its

corporate structure. As shown in Figure 2-3, the company’s power

MOSFET products and IGBT transistors accounted for

approximately 70 percent of fiscal 1997 sales. The remaining

30 percent resulted from sales of high-voltage control ICs, highperformance diodes, and high-power rectifiers and thyristors.

Motorola Incorporated’s semiconductor segment designs,

manufactures, and distributes discrete semiconductors and ICs.

Semiconductor sales accounted for 27 percent of Motorola’s total

revenue. Motorola produces a wide range of final products that use
Section 2 — The IGBT Supply Chain

2-13

1997

$3.8 billion

Communication

24.9%

Electronics

26.3%

Office

Equipment

30.9%

Semiconductors

17.9%

(Harris

Semiconductor)

aFiscal year ended June 27, 1997.

Source: Harris Corporation. August 29, 1997. 10-K405 for year ended June 27,

1997. EDGAR database: <http://www.sec.gov/Archives/edgar/data/202038/

0000950152-97-006326.txt>. Bethesda, MD: Lexis/Nexis.

1997 Revenues

$486 million

Power 

MOSFET and 

IGBT

70%

All Otherb

30%

aFiscal year ended June 30, 1997.

bAll other including high-power voltage controls, diodes, rectifiers, and thyristors.

Source: International Rectifier Corporation. September 26, 1997. 10-K405 for

year ended June 30, 1997. EDGAR database:

<http://www.sec.gov/Archives/edgar/data/316793/0000912057-97-031847.txt>.

Bethesda, MD: Lexis/Nexis.

power devices (MOSFETs and IGBTs) such as cellular phones,

portable radios, and modems. Motorola is vertically integrated to

the extent that it incorporates these IGBTs as an input in its

Figure 2-2. Distribution

of Harris Corporation

Sales by Segment:

1997a

Harris Semiconductor accounts

for about 18 percent of the

revenues of the Harris

Corporation.

Figure 2-3. Distribution

of International Rectifier

Sales by Product: 1997a

Seventy percent of International

Rectifier’s sales are from power

MOSFET and IGBT devices.
Benefit Analysis of IGBT Power Device Simulation Modeling

2-14

production of other products. In addition, Motorola sells

semiconductors directly to other customers.

Foreign Device Manufacturers

Japan is the leading foreign country manufacturing IGBT devices.

Most Japanese companies focus on devices with high current

capacity (200 to 1,000 amperes), and Japan is the predominant

world supplier of devices within this range. These devices are

hybrid in nature; that is, they contain multiple IGBT chips in

parallel. For example, an IGBT device with a capacity of 400

amperes may employ three IGBT chips in parallel. The following

Japanese firms manufacture IGBTs:

Z Fuji Electric (Japan)

Z Mitsubishi Electric (Japan)

Z Hitachi (Japan)

Z Toshiba (Japan)

Z ABB (Switzerland)

Z Siemens (Germany)

Z Samsung (Korea)

2.3.3 Applications Manufacturers

The majority of IGBTs are used in automobile and motor controls,

power controls, and lighting applications. These groups of

applications manufacturers are also the main users of simulation

modeling for IGBT design. Of these groups, the automotive and

motor control industries have the highest penetration of simulation

modeling for the design of IGBT systems.

Table 2-3 identifies the main device manufacturers that supply

IGBTs to the three major U.S. automotive manufacturers. Many

electrical system designs, such as ignition system design, are

typically contracted out or conducted by subsidiaries of the major

automobile manufacturing companies. For example, Delco

produces all of GM’s electronic systems. In contrast, basic research

on electric vehicles is conducted at the major automobile

companies’ laboratories. All the companies listed in Table 2-3 hold

SABER licenses.

All of the main device

manufacturers that supply

IGBTs to the auto industry

hold SABER licenses.
Section 2 — The IGBT Supply Chain

2-15

Automotive Company Main Suppler of IGBT Devices

Ford Motor Company Motorola

General Motors Delco Electronics

Chrysler Corporation Harris Corporation

Most motor control manufacturers are large multinational

conglomerates with diverse business interests; smaller firms tend

not to have the capital resources to compete against the larger

firms. Table 2-4 presents the major manufacturers of motor

controls and indicates which companies have SABER licenses and

are likely to be using simulation modeling in the design of their

motor control systems.

Company Currently Hold SABER License

Allen Bradley Yes

Eaton Yes

Micro Linear No

Reliance Yes

General Electric Yes

Warner Electric No

Renold Power Transmission No

Baldor No

AMK No

Transcoil No

Sprint Electric No

Rockwell International Yes

Sources: Analogy Inc.

A sample of major power control manufacturers is presented in

Table 2-5. Power control manufacturers are segmented into four

categories: welding, power correction, power conditioning, and

induction heating. Of the major companies in these categories,

only General Electric and Rochester Instrument Systems hold

SABER licenses.

Table 2-3. U.S.

Automobile

Manufacturers and Their

Primary Device Supplier

The three major U.S. auto

manufacturers each obtain their

IGBT devices from a different

supplier.

Table 2-4. Major U.S.

Motor Control

Manufacturers

Only five of the 13

manufacturers hold SABER

licences.
Benefit Analysis of IGBT Power Device Simulation Modeling

2-16

Company

Currently Hold

SABER License

Welding

ESAB No

Lincoln Electric No

Weltronic/Technitron Corp No

Weldlogic, Inc. No

Unitrol Electronics No

Thermadyne No

RoMan Manufacturing No

Robotron Corporation No

Polaris Electronics No

Miller Electric No

LaseRevolution Inc No

ITW Dynatec No

Power Correction and Power Conditioning

Northeast Power Systems No

Thunderbyrd Power Systems No

Phaseco, Inc No

Correction Controls No

Commonwealth Sprague No

Steelman Industries No

General Electric Yes

Arco Electric No

Chloride Power electronics No

Online Power No

MCG Surge Protection No

Oneac No

EFI Electronics No

PowerSmiths No

Rochester Instrument Systems Yes

Pribusin No

Induction Heating

Zion Industries No

Michigan Induction No

Lepel No

Inductotherm Industries No

EYE-HS USA No

Source: Analogy, Inc.

Table 2-5. Selected

Power Control

Manufacturers

Most power control

manufacturers do not use

SABER for simulation modeling.
Section 2 — The IGBT Supply Chain

2-17

Major U.S. manufacturers of compact fluorescents are presented in

Table 2-6. General Electric is the only manufacturer of compact

fluorescents identified that holds a SABER license.

Companies Currently Hold SABER License

OSRAM Sylvania No

Advance Transformer Company No

Advanced Lighting Technologies No

General Electric Yes

Genlyte No

Lights of America No

Howard Industries No

Renova No

Source: Analogy, Inc.

Table 2-6. U.S.

Manufacturers of

Compact Fluorescents

General Electric is the only

lighting manufacturer that holds

a SABER license.
3-1

Technical Impacts of

Simulation Modeling 3 of IGBT Devices

Simulation modeling of IGBT devices has had a significant impact

on the system design process and final performance of products

employing IGBTs. Modeling allows engineers to determine the best

design characteristics before physical prototypes are produced,

saving both time and money in the design process. A model can

improve product performance by determining the performance

range of a device and allowing an engineer to explore alternative

design scenarios in a more timely and efficient manner than if (s)he

had produced a physical prototype.

This section describes the technical impacts associated with using

mathematical modeling of IGBT devices. Table 3-1 summarizes the

technical impacts and categorizes them as impacts on R&D

efficiency, transaction costs, production costs, and final product

quality and performance. These technical impacts are described in

detail in this section.

3.1 IMPACTS ON R&D EFFICIENCY

Software incorporating NIST’s mathematical models is primarily

used for integrating the IGBT device into the electrical system of the

final product. We refer to this as the use of simulation modeling in

the system design process. Figure 3-1 shows the interaction
Benefit Analysis of IGBT Power Device Simulation Modeling

3-2

Table 3-1. Technical Impacts of Simulation Modeling of IGBT Devices

The use of simulation modeling of IGBT devices affects the design process, reduces the materials required for

manufacturing, improves the manufacturing process, and improves product quality and performance.

Benefit Categories Description of Technical Impact

R&D Efficiency Z Supports mathematical representation of the physical behavior of IGBT devices’

complex electrical characteristics in the silicon and enables analysis of how the

IGBT device interfaces with the electrical system design.

Z Allows IGBT device designers to gain an understanding of their design without

physically procuring materials and building a prototype.

Z Reduces the number of design iterations needed to develop a new product,

reducing labor and material inputs.

Z Enables concurrent design of IGBT devices and applications employing the

device for optimal performance of application.

Z Reduces R&D cycle design time. However, reduction in R&D design time is

typically not large enough to affect total product cycle design time.

Transaction Costs Z Reduces the cost of developing datasheets that provide information on device

performance over a range of operating conditions.

Z Enables more detailed datasheets allowing purchases of IGBTs to compare

products across different device suppliers.

Production Costs Z Reduces material needs associated with packaging the IGBT-based electrical

system in the final product.

Z Increases design precision, which enables lower tolerances and safety margins,

reduces size of capacitors and heat sinks needed.

Z Reduces final product defect rates.

Final product quality

and performance

Z Enables cost-effective analysis of alternative design scenarios—analysis of

multiple “what-if” scenarios helps optimize system design and increase

performance.

Z Provides more accurate information about the performance range of the IGBT

device—leads to increased product efficiency and improved product

characteristics.

between applications manufacturers, device manufacturers,

and software companies that support the system design

process.

Software companies license simulation software to both

applications and device manufacturers. Device and

applications manufacturers typically work closely together in

the system design process, exchanging software models and

device information in an iterative process. Device

manufacturers use SABER to develop software models for new

As shown in Figure 3-1, software

incorporating NIST’s mathematical

models is not typically used to

design IGBT power devices. Device

engineers use finite element and

two-dimensional models to develop

the physical parameters of the IGBT

devices.
Section 3 — Technical Impacts of Simulation Modeling of IGBT Devices

3-3

Figure 3-1. The Interaction of Design Activities Among Members of the Supply Chain

Designing electrical systems incorporating IGBTs requires interaction among the software companies, the device

manufacturers, and the applications manufacturers.

Provide

Simulation

Software

Support

Component

Library

Develop/Use

Simulation Models

for System Design

Develop

Simulation

Models

Develop

Datasheets

IGBT

Device

Design

Software Companies

Applications

Manufacturers

Device

Manufacturers

IGBT devices to support applications manufacturers’ system design

activities. Device manufacturers also use SABER’s simulation

capabilities to develop IGBT device datasheets.

Datasheets provide information on static device performance so

that applications manufacturers can compare IGBT devices from

different venders over a variety of operating conditions.

Only large applications manufacturers develop their own IGBT

simulation models. Most applications manufacturers use either

models provided by device manufacturers or models contained in

component libraries supported by software companies. Once a
Benefit Analysis of IGBT Power Device Simulation Modeling

3-4

model has been developed, it is usually placed in the public

domain (on the Internet) or included in the component library.

Identifying the steps conducted in a typical system design process is

difficult because the activities required vary greatly across end-use

applications (Clemente, 1997). Some of the factors that influence

system design activities are

Z the size (voltage) and complexity of the electrical system,

Z the interaction of the IGBT-based components with other

components in the system,

Z whether “off the shelf” IGBT component models are

available or if a new simulation model must be developed,

and

Z whether the design is for a new system or is a re-design of

an existing system.

The following is a description of a typical system design process

without and with simulation modeling.

3.1.1 Description of the System Design Process Without

Simulation Modeling

Figure 3-2 illustrates the flow of a “typical” system design process

without simulation modeling. After the initial product conception

and product design, system performance parameters and IGBT

device specifications are determined and an IGBT device is

selected. During the system design process, the IGBT device is

integrated into the electrical system and a physical prototype (also

referred to as a mask) is developed and tested in a breadboard

configuration. One of the main purposes of the breadboard testing

is to determine the performance range of the device.

In most cases a system designer physically “fails” the device and

the prototype is destroyed. In these situations the system designer

will then work very closely with the device manufacturer to redesign the device to meet the desired power requirement. This is

commonly referred to as a physical design iteration. It is not

uncommon for the system design to entail five to six design

iterations. Each design iteration typically takes several weeks and

requires the construction of a new physical prototype.
Section 3 — Technical Impacts of Simulation Modeling of IGBT Devices

3-5

Figure 3-2. System Design Process Without Simulation Modeling

In the absence of simulation modeling, the design sometimes requires as many as six physical design iterations before

passing.

Product Conception

Initial Product Design

IGBT Testing in Breadboard

Product Prototype

IGBT Device Production

Final Product Production

IGBT Device and Specifications

from Device Manufacturers

IGBT

Specs

Physical Design Iteration

Pass

Fail

IGBT Selection

System Design

Masking: Physical

Prototype Development

Performance

Parameters

Once the IGBT device prototype passes the breadboard test, the

device specifications and performance parameters are passed on to

production or the next design tier.

3.1.2 Description of the System Design Process With

Simulation Modeling

Figure 3-3 illustrates the system design process using simulation

modeling of IGBTs. The main advantage of using simulation

modeling in system design is that it enables virtual testing of
Benefit Analysis of IGBT Power Device Simulation Modeling

3-6

Figure 3-3. System Design Process with Simulation Modeling

With simulation modeling, the design often passes with fewer iterations.

Product Conception

Initial Product Design

IGBT Testing in Breadboard

Product Prototype

IGBT Device Production

Final Product Production

NIST

Simulation Software

Mathematical

Modeling

IGBT

Specs

Performance

Parameters

Fail

Pass

Pass

Fail

IGBT Selection

System Design

Virtual Testing

Masking: Physical

Prototype Development

IGBT Models from Device

Manufacturers or Component

Library

Physical Design Iteration

Virtual Iteration

alternative designs before the development of physical prototypes

(virtual iteration). Because simulation models can accurately

predict device performance, they enable the simulation of “what

if” scenarios.

By investigating alternative design scenarios in a virtual

environment, the number of physical iterations required to “pass” a

device can be significantly reduced. The use of simulation

modeling will almost always eliminate one physical iteration from
Section 3 — Technical Impacts of Simulation Modeling of IGBT Devices

3-7

the design process and frequently will eliminate three to four

physical iterations (Benjakowski, 1998).

3.1.3 Summary of the Technical Impacts of Simulation

Modeling on System Design Process

Simulation modeling based on mathematical models of IGBTs

enables virtual testing of systems. Virtual testing affects the design

process in the following ways:

Z The use of simulation modeling enables representation of

the physical behavior of IGBTs’ complex electrical

characteristics in the silicon and how the device interfaces

with the system design.

Z IGBT designers gain an understanding of their design

without physically procuring materials and building a

prototype.

Z With simulation modeling, a design may require only one to

two iterations. Historically, IGBT design would require

three to four iterations.

Z The use of simulation modeling enables concurrent design

of IGBT systems and applications employing the device,

minimizing overall R&D cycle design time and improving

performance of the application.

Z Having fewer redesign iterations leads to reductions in labor

and materials. Reductions are generally proportional to the

number of iterations reduced.

Z Mathematical models of IGBTs also affect the performance

range of the system devices. Mathematical modeling

enables designers to test their systems at all ranges to

determine if a given IGBT design will meet multiple design

and performance requirements.

Z Simulation modeling increases the fixed design costs of

purchasing and maintaining the required software and

hardware and training designers to use them.

3.2 IMPACT ON TRANSACTION COSTS

Device manufacturers use simulation modeling of IGBTs to

generate datasheets for each new family of IGBTs developed.

Datasheets provide information on static performance so that

buyers can compare IGBT devices from different venders over a

variety of operating conditions.

The use of simulation modeling significantly reduces the cost of

developing a datasheet for a new device. Without simulation

The use of simulation

modeling enables

representation of the

physical behavior of IGBTs’

complex electrical

characteristics in the

silicon and how the device

interfaces with the system

design.
Benefit Analysis of IGBT Power Device Simulation Modeling

3-8

modeling, device design engineers need to conduct hundreds of

measurement tests per datasheet to manually plot out behavioral

curves. With simulation modeling, they can map IGBT device

behavior using only a few physical test points to verify the

simulated behavioral curves.

Using simulation modeling to develop datasheets also increases the

range and quantity of information that can be cost effectively

provided on datasheets. This reduces search costs for purchasers of

IGBTs by enabling them to more efficiently compare device

performance across different suppliers.

3.3 IMPACT ON PRODUCTION COSTS

The use of simulation models in the system design process may also

affect material costs and manufacturing costs. Simulation modeling

enables the reduction in engineering safety margins for system

components and packaging, which in turn reduces the cost of

manufacturing. The superior predictive capabilities of IGBT

simulation models can be used by product design engineers and

module engineers minimize the use of materials (such as silicon).

For example, the use of IGBT simulation models can reduce the

number and size of capacitors and heat sinks used in a system,

resulting in a reduction of the dimensions and weight of some

systems by about 20 to 30 percent (Et-Info, 1997). In addition, the

IGBT’s smaller size also lowers integration costs, reduces

complexity, and increases reliability of the component, thus leading

to fewer defective parts.

3.4 IMPACT ON PRODUCT QUALITY AND

PERFORMANCE

Simulation modeling also leads to increased performance of

products employing IGBTs. Concurrent design and more accurate

information on the performance range of the IGBT generated by

NIST’s mathematical models enables designers to increase the

efficiency of their final products. Increased fuel efficiency was one

of the main motivating factors in the automotive industries’

decision to adopt simulation modeling for the design of ignition

systems.
Section 3 — Technical Impacts of Simulation Modeling of IGBT Devices

3-9

Additional examples of potential product quality and performance

improvements resulting from the use of simulation modeling of

IGBTs include

Z increased accuracy of roboting equipment,

Z decreased electricity consumption of ASDs in industrial and

HVAC applications,

Z increased lighting quality, and

Z decreased noise (hum) of electrical equipment.
4-1

Methodology for

Estimating 4 Economic Impacts

The methodology used in the quantitative analysis provides reliable

and conservative (lower-bound) estimates of the social benefits

associated with NIST’s contributions to the simulation modeling of

IGBTs. Our approach is to include in the quantitative analysis only

impacts that have been explicitly identified and quantified by

industry experts. For many of the impacts described in this section,

industry experts identified impact areas but were not able to

quantify the impacts in terms of technical or economic metrics.

These hard-to-quantify impacts are not included in the benefits

estimates but instead are discussed qualitatively with examples that

illustrate the potential magnitude of economic benefits.

This section begins with a graphical presentation of our

methodology to estimate economic benefits. This is followed by

the definition of benefit and cost categories and the technical and

economic metrics used to quantify impacts associated with these

benefit and cost categories. The section concludes with an

overview of the data collection process.

4.1 ECONOMIC MODEL

Figure 4-1 illustrates the conceptual framework and associated

taxonomy used in the quantitative analysis. The framework defines

the benefit and cost categories used in the analysis and helps

ensure that all impacts are accounted for and that benefits or costs

are not double-counted.
Benefit Analysis of IGBT Power Device Simulation Modeling

4-2

Figure 4-1. Defining Benefits and Costs

The total benefits of the use of simulation modeling of IGBTs is represented by areas A and B. The total costs are

represented by areas C and D.

Part (a)

Full Benefits Associated with

Simulation Modeling Using SABER

Part (b)

Full Costs Associated with

Using SABER

Development

Costs

User

Costs

System

Design

Benefits

ProductLevel

Benefits

A

C

NIST

D

Private

NIST

Benefits Related to IGBTs

B

A′ B′

IGBT’s Share of Costs

C′

C′′

As discussed in the following section, our quantitative analysis

focuses on the use of Analogy’s software product SABER for

simulation modeling of IGBTs. However, because IGBT modeling

is only one small component of SABER’s modeling capabilities we

begin by looking at the larger picture of the full benefits and costs

associated with using SABER.

Part (a) of Figure 4-1 represents the full social benefits associated

with simulation modeling using SABER. Benefits are segmented

into two categories:

Z benefits realized during the system design process, such as

decreased labor costs or decreased material costs for

physical prototypes, and

Z product-level benefits, such as decreased manufacturing

costs and improved product performance.

The benefits associated with simulation modeling of IGBTs are a

subset of the full benefits of using SABER. These are represented by

the shaded area in Part (a) of Figure 4-1 (Area A and Area B).
Section 4 — Methodology for Estimating Economic Impacts

4-3

The inner area in the benefits figure is the portion of benefits

attributed to NIST’s contributions to the development and

promotion of IGBT simulation modeling.1 NIST-related benefits are

a subset of the benefits associated with simulation modeling of

IGBTs. As shown in the figure, NIST’s contributions have generated

benefits in both the system design category (area A’) and in the

product-level category (Area B’).

Part (b) of Figure 4-1 represents the full social costs of using SABER

for simulation modeling. Costs are also segmented into two

categories: development costs and user costs. Development costs

are the R&D costs associated with SABER development and

promotion that are not captured in SABER licenses, maintenance

fees, or component library lease fees. User costs are the costs

device and applications manufacturers incur for adopting SABER for

simulation modeling. User costs include software costs, such as

software licenses, maintenance fees, component library lease fees,

and training costs for staff to learn how to use SABER.

The shaded areas in Part (b) of Figure 4-1 (Area C and Area D)

represent the portion of costs associated with simulation modeling

of IGBTs. This includes both development costs (Area C) and user

costs (Area D). Development costs associated with simulation

modeling of IGBTs are further subdivided into NIST simulation

modeling program expenditures (area C’) and private expenditures

(Area C’’).

4.1.1 Net Benefits from Simulation Modeling of IGBTs

Based on the areas in Figure 4-1, the net benefits to society

associated with the simulation modeling of IGBTs are defined as

the design process benefits and product-level benefits, less the

development costs and user costs:

Net Benefits to Society = (Area A + Area B)

– (Area C + Area D). (4.1)

The net benefits are based on the counterfactual of IGBT simulation

modeling capabilities not being available to device and application

 1Areas A’ and B’ in Figure 4-1 represent the benefits that would not have occurred

in the absence of the NIST simulation modeling program. Industry stated that

IGBT mathematical models would not have been as accurate and would not

have been incorporated into SABER as quickly without NIST’s contributions.

Software costs are actually

transfer payments between

the developer and user of

the simulation modeling

software. They do not

affect the size of net

benefits. We have

included software costs on

the user side because it is

difficult to quantify private

R&D (C’’). Our modeling

approach is to assume that

private R&D costs net of

software revenue is

approximately zero (i.e.,

software company profit

from developing IGBT

modeling ≈ 0). In this way

we minimize the impact of

not being able to quantify

private R&D expenditures.
Benefit Analysis of IGBT Power Device Simulation Modeling

4-4

manufacturers. Thus, the size of areas A and B are determined by

comparing the current situation (with simulation modeling) with the

counterfactual situation in which all products using IGBTs are

design without simulation modeling.

4.1.2 Net Benefits from NIST’s Contributions to Simulation

Modeling of IGBTs

To estimate the net benefits associated with NIST’s expenditures,

we need to know NIST’s share of development costs (area C’) and

the share of benefits attributable to NIST’s contributions (Area A’ +

Area B’). With this information, the net benefits from NIST’s

expenditures could be expressed as

NIST Net Benefits = (Area A’ + Area B’) – (Area C’) (4.2)

NIST’s share of costs is theoretically simple to calculate; Area C’ is

NIST’s simulation modeling program expenditures. However,

NIST’s share of benefits is much more difficult to estimate. NIST’s

share of IGBT simulation modeling benefits is measured relative to

the counterfactual that reflects IGBT simulation modeling

development and adoption in the absence of the NIST simulation

modeling program.

As discussed in the following section, industry experts confirmed

that NIST has made a “significant“ contribution to the development

and adoption of simulation modeling of IGBTs. However, none of

the industry experts could provide adequate information for the

development of a “without”-NIST counterfactual baseline.

In the absence of a without-NIST counterfactual baseline, the net

benefits associated with NIST’s contributions are defined in terms of

a NIST impact coefficient (IC) and the net benefits to industry. The

NIST impact coefficient is defined as a fraction between zero and

one that represents NIST’s relative contribution to the development

and adoption of simulation modeling. The advantage of using a

single impact coefficient is that sensitivity tests can be conducted

for estimated values of NIST’s impact.
Section 4 — Methodology for Estimating Economic Impacts

4-5

Net benefits associated with the NIST simulation modeling

program, defined in terms of the NIST impact coefficient and the

net benefits to industry and are expressed as2

Net Benefits to Industry = (Area A + Area B) – (Area C’’ +

Area D)

NIST Net Benefits = NIST’s Impact Factor * [net benefits to

industry – NIST Expenditures]

The NIST benefit-cost ratio is similarly defined as NIST’s share of

net benefits to industry divided by the NIST simulation modeling

program expenditures.

NIST Benefit-Cost Ratio = NIST Impact Factor * Net Benefit to Industry

NIST Expenditures

4.2 CALCULATING BENEFIT AND COST

CATEGORIES

The benefit and cost categories in Figure 4-1 represent flows of

benefits and costs over time. The net present value (NPV) of these

benefit and cost flows are calculated by adjusting for inflation and

by discounting using the social (real) discount factor of 7 percent

(OMB, 1995).

4.2.1 Benefits Categories

Benefits are divided into design-level benefits and product-level

benefits. This distinction is important because for design-level

impacts the unit of analysis is the number of times a design process

is conducted and for product-level benefits the unit of analysis is

the number of products sold.

For example, the use of IGBT simulation modeling can reduce the

number of design iterations needed to develop a new product (or

redesign an existing product). These cost reductions occur each

time a system design process is conducted and are a portion of

fixed costs in that they are independent of the number of units

 2Alternatively, we could have defined NIST net benefits as

NIST Net Benefits = [IC * (Area A + Area B)] – Area C’.

However, this definition does not incorporate information on SABER user costs

and in effect assumes that NIST has no impact on user costs. Our approach

assumes that IC affects all these things equally.
Benefit Analysis of IGBT Power Device Simulation Modeling

4-6

produced. In contrast, the unit of analysis for changes in

manufacturing costs and improvements in product quality is the

number of units produced and sold.

Design-Level Benefits

Simulation modeling decreased the cost of designing an IGBT

system. These cost savings occur each time a new IGBT system is

designed. In some cases, the system is custom designed for a

narrowly defined product, such as an ASD for a specialized motor

application; in other cases, the system is designed to be used in an

entire class of products, such as an ignition system for an entire line

of automobiles.

The system design process is defined as all steps leading up to and

including the successful testing (“passing”) of the IGBT device in

the breadboard (physical) product prototype.3 Benefits are

generated primarily from reducing the number of physical design

iterations.

Reducing the number of physical design iterations may lead to both

direct and indirect benefits. Direct benefits include material cost

savings from fewer physical prototypes and labor cost savings from

reduced R&D design cycle time.

Indirect benefits may occur if the reduction of physical design

iterations reduces coordination costs or leads to a reduction in the

overall product design cycle. Coordination costs result from idle

resources or missed delivery dates due to bottlenecks in the product

design process. For example, a supplier may not meet his or her

delivery date if an unexpectedly large number of physical iterations

are required during the system design process. In addition,

reducing the overall product design cycle may generate benefits by

accelerating the introduction of new products.4

Our approach for estimating design-level benefits is to estimate

incremental impacts for “typical” design processes and then to

weight them by the average number of design processes conducted

per year. A series of “typical“ application design processes are

 3See Section 3.1 for a detailed description of the IGBT system design process.

4See Appendix B for a discussion of the benefits from accelerating the introduction

of new product.

Indirect benefits

may occur if the

reduction of

physical design

iterations reduces

coordination costs

or leads to a

reduction in the

overall product

design cycle.
Section 4 — Methodology for Estimating Economic Impacts

4-7

modeled, such as automotive ignition systems, ASDs, and compact

fluorescent lamp ballasts.

The system design benefits for an application i in year t are

expressed as

System Design Benefitsit = (∆material costsi + ∆labor costsi +

∆coord costsi + accel benefitsi) *

Dit

where

∆material costsi = change in the material costs for a system

design for application i,

∆labor costsi = change in the labor costs for a system

design for application i,

∆coord costsi = increased coordination costs associated

with reduced overall product design time,

accel benefitsi = benefits from accelerating the introduction

of a new product in application i, and

Dit = the number of system designs conducted in

year t for application i.

Product-Level Benefits

The use of IGBT simulation models in the system design process

can also affect production costs and product quality and

performance. Both of these are product-level benefit categories that

depend on the number of units produced and sold over time. As

described in Section 3, simulation modeling of IGBT devices can

affect the cost of production by reducing material costs associated

with heat sinks and packaging. In addition, simulation modeling

can lead to improvements in product quality and performance,

such as increased fuel efficiency, decreased maintenance, and

decreased operating noise (hum).

Individual product-level benefits for each applications in year t are

weighted by the number of units sold each year:

Product-level Benefitsit =[∆production costsi + ∆product

qualityi] * Qit

In addition to the flow of

benefits being generated

over time as products are

produced and sold,

product quality

improvements have a

second time dimension

because benefits accrue to

individual units over their

life time.
Benefit Analysis of IGBT Power Device Simulation Modeling

4-8

where

∆production costsi = change in material costs per unit for

application i,

∆product qualityi = NPV of product quality and

performance improvements over the

life time of the product for application

i, and

Qit = number of units produced and sold in

year t of application i.

The above approach to estimating product-level benefits is

frequently referred to as a bottom-up approach—impacts per unit

are estimated and then weighted by the number of units sold.

Alternatively, a top-down approach could be used. In the topdown approach aggregate national statistics are typically used as

the starting point for the analysis. For example, to calculate the

product quality benefits from simulation modeling of automobile

ignition systems, the analysis would multiply the total annual

gasoline consumption in the U.S. by an estimate of the relative

(percentage) impact IGBT simulation modeling has had on overall

fuel efficiency. A top-down approach has the advantage of

providing an upper-bound estimate of benefits (total gasoline

consumption) and is useful for gaining insight into the potential

range of benefits when detailed product-level information is not

available.

In Section 5 we use the top-down approach to develop estimates of

the potential magnitude of benefits. These product-level benefits

estimates are not included in the quantified benefit estimates

because of uncertainty in measuring the underlying impact metrics.

4.2.2 Cost Categories

The cost to society from using IGBT simulation models in the

system design process includes both the development costs and

user costs associated with SABER. NIST simulation modeling

program expenditures are included in development costs.

Development Costs

Development costs include the basic development of IGBT

mathematical models, verification of the models, and incorporation

of the models into the SABER software. NIST made significant
Section 4 — Methodology for Estimating Economic Impacts

4-9

contributions in all three of these design areas. NIST developed the

basic mathematical models, worked with device and applications

manufacturers to verify the models, and worked with Analogy to

incorporate the mathematical models into SABER.

As illustrated in Figure 4-1, our modeling approach segments

development costs into NIST expenditures and private

expenditures. Development costs occur over time and are

expressed as

Design Costst = NIST expt + Private expt

where

NIST expt = NIST simulation modeling program

expenditures in year t,

Private expt = device manufacturers, applications

manufacturers, and software company

(Analogy) expenditures in year t (net of

revenue from user costs).

User Costs

User costs include expenditures by device and applications

manufacturers to purchase, support, and integrate SABER’s IGBT

simulation modeling capabilities into their design activities. User

costs include the fixed (one-time costs) of purchasing the SABER

software and variable (annual) costs of maintenance fees,

component library fees, and staff training.

The user cost information collected during the interviews with

industry experts reflects expenditures and training associated with

all SABER activities. However, because SABER is used for many

design activities not involving IGBT systems, these total SABER

costs are scaled by the percentage of time SABER is used for IGBTrelated design activities.

User costs are developed for a series of typical research facilities,

representing the different end-use applications employing IGBTs.

Typical research facility user costs are expressed as

User Costsi = [Fixed Costsi + Σ (Variable Costsit)] *

IGBT Sharei
Benefit Analysis of IGBT Power Device Simulation Modeling

4-10

where

fixed costsi = cost of purchasing SABER licenses for

facility type i,

variable costsit = annual SABER maintenance fees,

component library fees, and staff training

for facility type i in year t, and

IGBT sharei = percentage of SABER activities involving

IGBT design for facility type i.

4.3 AGGREGATING ECONOMIC IMPACTS

To aggregate economic impacts, benefits and costs are grouped into

two categories: net benefits to industry and NIST simulation

modeling program expenditures. Benefit and cost flows over time

are adjusted to 1998 dollars and then discounted by the social

discount rate of 7 percent to obtain the NPV of the net benefits to

industry (NPV industry) and NPV of NIST expenditures (NPV NIST

exp).

Figure 4-1 graphically illustrates the relationship between the net

benefits to industry and NIST expenditures. The benefit and cost

areas in Figure 4-1 represent the NPV of the benefits and costs from

the beginning of the NIST simulation modeling program (1985)

through the competitive life of the IGBT mathematical models

incorporated into SABER. Industry experts indicated that the

current version of IGBT simulation modeling in SABER is expected

to remain the dominant IGBT software model for at least the next

5 years. Thus, for the purpose of this study, we have projected

benefits and costs through the year 2003.

The quantitative analysis presented in Section 5 includes all

benefits and costs discussed in Section 4.1 and Section 4.2, with

the exception of

Z product-level benefits and

Z private design costs.

As discussed in detail in the following section, industry experts

were not able to provide sufficient information to reliably quantify

product-level benefits and private design costs associated with

IGBT simulation modeling.
Section 4 — Methodology for Estimating Economic Impacts

4-11

As a result, the economic impact estimates presented in Section 5

are estimated as follows. The NPV of net benefits to a typical

research facility in applications industry i is defined as

NPV Net Benefits i =∑

j=0

n Benefitsi,t+j – Varianti,t+j IGBT Sharei

(1+r)j

– 

Fixed Costsi * IGBT Sharei

(1+r)(t-t*)

where

r = social discount rate of 7 percent,

t = base year of 1984,

j = 0 corresponds to the beginning of 1985

j = 1 corresponds to the end of 1985

t* = year in which fixed costs occurred, and

n = 18 (year 2003).

All benefits and costs are expressed in 1998 dollars.

Typical research facility-level net benefits are weighted by the

number of research facilities in each applications industry that hold

SABER licenses. And all applications industries are summed to

obtain the NPV to industry:

NPV to Industry = Σi (NPV Net Benefits i*ni)

where

ni = the number of research facilities in applications industry

i with SABER licenses.

The NPV of NIST simulation modeling program expenditures is

expressed as

NPV NIST exp = ∑

j=0

n Ct+j

(1+r)j

where

C = real expenditures in 1998 dollars in year t, including

labor, equipment, and miscellaneous costs;

r = social discount rate of 7 percent;

t = base year of 1984; and

j = 0 corresponds to the beginning of 1985
Benefit Analysis of IGBT Power Device Simulation Modeling

4-12

j = 1 corresponds to the end of 1985

n = 18 (year 2003).

4.3.1 Measures of Social Return to NIST Expenditures

The NPV of the NIST simulation modeling program is defined as

NPV NIST = (NPV to Industry * NIST Impact Factor) – NPV

NIST Expenditures.

The benefit to cost ratio of the NIST simulation modeling program

is defined as

Benefit-to-Cost = (NPV to Industry * NIST Impact Factor)

/NPV NIST Expenditures.

Finally, the social rate of return of the NIST simulation modeling

program is the social discount rate that equates the NPV of the

NIST simulation modeling program to zero.

4.4 IMPACT MEASURES

To operationalize our modeling approach, we collected

information on technical and economic impact metrics. Technical

impact metrics describe the effects of mathematical modeling on

the design and manufacturing process and on the final product

employing the IGBT device. Economic impact metrics describe

how the technical impacts translate into changes in design and

manufacturing costs and into changes in consumers’ valuation.

Table 4-1 summarizes the technical and economic impact metrics

used to support the estimation of the economic benefits from IGBT

simulation modeling. The information contained in Table 4-1 was

collected through interviews with applications, device, and

software manufacturers and developed from secondary data

sources.

4.5 DATA COLLECTION PROCEDURES

Surveys of applications, device, and software manufacturers and

secondary data sources were used to support the estimation of

economic impacts. The survey instruments for the three groups are

contained in Appendixes C, D, and E.
Section 4 — Methodology for Estimating Economic Impacts

4-13

Table 4-1. Metrics for Estimating Economic Benefits

These metrics were used to support the estimation of the economic benefits.

Impact Category Components Technical Metric Economic Metric

Design-Level

Benefits

∆labor costsi Decreased labor hours per system

design

(Number of labor hours per iteration) X

(Labor cost per hour [or average wage

rate])

∆material costsi Decreased materials inputs

system design

(Material costs for physical prototype) X

(The reduction in the number of

iterations)

Coordination

costsi

Decrease in the number of weeks

for total product design cycle

(Length of delay) X (The opportunity

cost of idle resources per period of

delay)

Acceleration

benefitsi

Length of time product

availability is advanced

Increased valuation of new product

compared to old product

Product-Level

Benefits

∆production

costsi

Change in manufacturing

equipment, raw materials, or

labor used in the production

process

(Number of units produced) X (Cost

savings per unit)

Change in the number of

defective units

(Change in number of defects) X (The

cost per defect)

∆product

qualityi

Increased energy efficiency, such

as energy-efficiency rating (EER)

or fuel consumption

(Energy savings) X (Fuel price) X (The

number of units sold)

Changes in maintenance

requirements

(Cost per maintenance or service call) X

(The average reduction in calls) X (The

number of units sold)

Development Costs NIST

expenditurest

Labor hours of NIST staff to

support program

(Number of labor hours) X (Wage rate)

Equipment to support program Equipment expenditures

Private

expenditurest

Private labor hours to support

model testing and verification

(Number of labor hours) X (Wage rate)

Equipment to support model

testing and verification

Equipment expenditures

User Costs Fixed costsi Software and the number of

licenses

License costs for SABER

Variable costsit Software maintenance (Initial software cost ) X (Percentage

maintenance fee)

Component library fee Rental free for component library

Labor hours devoted to training (Number of hours) X (Labor cost per

hour [or average wage rate])
Benefit Analysis of IGBT Power Device Simulation Modeling

4-14

Figure 4-2 illustrates the sampling strategy for the surveys. A

purposive sample of nine applications manufacturers was used to

identify benefits and costs in the automotive, motor control, power

control, and lighting industries. Applications manufacturers were

the primary source of information for research facility-level impacts

associated with simulation modeling.

Figure 4-2. Sampling Plan for Surveys

We conducted interviews with software and manufacturing companies in the semiconductor power-device supply

chain.

Supply Chain Preliminary Sampling Plan

Consumers of End Products

Employing IGBT Devices

Manufacturers of Products

Employing IGBT Devices

Manufacturers of IGBT

Devices

Software Companies

Supporting Power-Device

Modeling

No primary data collection

Purposive Sample

(did not exceed nine)

Census of Major

Manufacturers

(did not exceed nine)

Census of Major Companies

(did not exceed nine)
Section 4 — Methodology for Estimating Economic Impacts

4-15

Surveys of the device and software manufacturers (not exceeding

nine in either group) were conducted to investigate the impact

NIST’s contributions have had on the development and adoption of

mathematical modeling in the design process. This information

was used to identify the portion of economic benefits associated

with mathematical modeling that can be attributed to NIST’s efforts.

In addition, information from the software and device

manufacturers’ surveys was used to develop weights to expand

research facility-level economic impacts to industry- and nationallevel impacts.

Secondary data were used to develop the quantity of units sold over

time and to supplement information on the change in product

quality and performance. For example, in the absence of survey

information, the change in unit efficiency was used to calculate

energy savings as a proxy.
5-1

5 Analysis Results

NIST’s contributions to the development of simulation modeling

tools for IGBT power devices have led to significant economic

benefits through reduced design costs and improved performance

of products employing IGBTs. Estimated benefit-cost ratios from

the NIST program range from 15.5 to 31.0 and estimates of the

social rates of return to NIST simulation modeling program

expenditures range from 67.4 percent to 85.6 percent. In this

section we present the information and procedures used to

calculate economic impacts.

The actual economic impact from the NIST program is likely to be

larger than the estimates presented in this section because

improved product performance was not included in the quantified

benefits estimates. In most instances, industry experts could not

quantify the benefits of simulation modeling on final product

performance. As a result, the benefit and cost estimates presented

in this section are based primarily on reduced labor costs in the

design process and the user costs associated with adopting

simulation modeling tools, respectively.

This section begins with an overview of the methodology and

taxonomy used in the quantitative analysis and a summary of the

findings from the interviews with industry experts. Then we present

the estimation procedure used to quantify NIST’s contributions,

which consisted of five steps:

Z Estimate laboratory-level benefits and costs and calculate

net benefits
Benefit Analysis of IGBT Power Device Simulation Modeling

5-2

Z Weight laboratory-level net benefits to obtain national net

benefits to industry.

Z Estimate NIST’s share of net benefits to industry.

Z Calculate NIST simulation model program expenditures.

Z Calculate benefit-cost ratios, social rate of return, and NPV

associated with the NIST simulation modeling program.

5.1 OVERVIEW OF METHODOLOGY AND

TAXONOMY

In terms of the conceptual framework presented in Section 4, our

method for quantifying the economic impact of the NIST program is

summarized below.

Benefits

Z Use technical interviews with industry experts to identify

the system design and product-level benefits associated with

simulation modeling of IGBTs.

Z Quantify the system design benefits (product-level benefits

will be included in the qualitative analysis).

Z Identify NIST’s share of benefits.

Costs

Z Use technical interviews with industry experts to quantify

user costs associated with SABER modeling.

Z Identify the percentage of SABER activities associated with

simulation modeling of IGBTs and use this percentage to

estimate IGBT user costs.

Z Estimate the NIST simulation modeling program

expenditures.

Based on the categories described above, the net benefit to industry

is defined as system design benefits less IGBT user costs associated

with the simulation modeling of IGBTs.

To estimate the benefit-cost ratio and the social rate of return from

the NIST program we need NIST’s program expenditures and NIST’s

share of net benefits to industry. The share of net benefits to

industry attributed to the NIST program is determined through the

technical and scoping interviews with industry experts.

NIST BenefitCost Ratio = Net Benefits to Industry x NIST’s Share

NIST’s Program Expenditure
Section 5 — Analysis Results

5-3

5.2 SUMMARY OF INTERVIEWS

To gather data for the analysis, four sets of telephone interviews

were conducted with industry representatives from the major

segments of the IGBT modeling supply chain, software companies,

device manufacturers, applications manufacturers, and academic

institutions. Table 5-1 shows the number of technical and scoping

interviews conducted for each of the four surveys. Appendix F

contains the list of respondents and their company/university

affiliation.

Table 5-1. Number of Interviews by Type and Sector

Our interviews included the two major software companies, the three major device manufacturers, and selected

applications manufacturers in the automotive and motor control, power control, and lighting industries.

Interview Group Number of Technical Interviews Number of Scoping Interviews

Software companies 2 2

Device manufacturers 3 3

Applications manufacturers 7 1

Academic institutions 4

The technical interviews were the primary source of detailed

technical and economic data used to quantify the benefit and cost

estimates that follow in this section. These interviews were

conducted mostly with design and modeling engineers. Technical

interviews with applications manufacturers targeted automotive

manufacturers and industrial manufacturers of motor control, power

control, and lighting systems. Industry experts indicated that these

were the major end-use application groups using IGBTs in their

electrical systems.

The scoping interviews were primarily used to identify penetration

and adoption issues associated with using simulation modeling and

to identify the industries that are using (and the industries not using)

simulation modeling for the design of IGBTs. In addition, these

interviews were used to gather information about design practices

outside of the study’s four application focus areas. The scoping

interviews were conducted with both engineers and upper
Benefit Analysis of IGBT Power Device Simulation Modeling

5-4

management personnel and also included representatives from the

academic sector.

5.3 TECHNICAL AND ECONOMIC IMPACTS OF

IGBT SIMULATION MODELING

The technical and economic impacts presented in this subsection

are based on the technical interviews conducted with industry

representatives. Impacts are divided into R&D efficiency impacts,

transaction cost impacts, and production and product

quality/performance impacts.

5.3.1 R&D Efficiency Impacts

Simulation modeling of IGBTs affects the system design process by

reducing the number of physical design iterations and reducing

labor costs. Most modeling and design engineers did not think

there were material cost savings (in the systems design process)

associated with simulation modeling.

NIST’s model is primarily used for integrating the IGBT device into

the electrical system of the final product. We refer to this as the use

of simulation modeling in the system design process. All of the

benefits and costs associated with simulation modeling of IGBTs

are based on the use of SABER. Thus, the terms “simulation

modeling of IGBTs” and the use of “SABER to model IGBTs” are

used interchangeably.

Typically the device and applications manufacturers work closely

together in the system design process, and simulation modeling

leads to fewer labor hours for both parties. Because the number of

labor hours reduced varies by end-use application, in our

discussion and calculation of benefits below we have grouped the

system design process impacts for device and applications

manufacturers together and presented them by end-use application

(e.g., automotive, motor control).

Benefits and costs associated with the impacts on the system design

process were estimated at the research facility level. A large

company may have several research facilities (or divisions)

conducting simulation modeling, with each research facility

purchasing its own software licenses and providing its own

modeling support staff in-house. When appropriate, design
Section 5 — Analysis Results

5-5

activities within a research facility were segmented by product

type, such as small versus large drive design, to capture variations

in design complexity.

Design benefits and user costs are discussed below segmented into

three application categories: automobiles, motor controls, and

additional applications.

Applications Manufacturers

Automotive Industry. Ford uses SABER to conduct simulation

modeling in the design of electronic ignition systems for all their

vehicles and in the design of power drives for electric cars.

Detailed telephone interviews were conducted with design

engineers at Ford Motor Company and Visteon Electronics Division

(a fully owned subsidiary of Ford).

Ford was actively involved in developing and testing the final IGBT

models that were incorporated into SABER (see Donnelly and

Gauen, 1994). Ford first began using simulation modeling of IGBTs

in their ignition system design process in 1991. At that time the

basic ignition system design had been completed; thus, the primary

use of simulation modeling for ignition systems to date has been in

the redesign process.1 Redesigns are required in response to the

continuing “shrinkage” of Motorola’s IGBT devices, advances in

ignition coil technology, and increased performance specifications

to meet government fuel efficiency mandates (Kirksey, 1998).

A summary of the benefits associated with the simulation modeling

of IGBTs for ignition systems is presented in Table 5-2. Ford

conducts on average two ignition system redesigns per year that

involve IGBT modeling. The same basic system design is used in

all of Ford’s combustion vehicles; thus, separate ignition system

design processes are not required for each make and model. Ford

estimates that using simulation modeling for ignition system

redesign leads to a reduction of one iteration in the redesign

process and that each iteration requires 40 percent of four design

engineers’ time over a 2.5-month period.

 1The use of simulation modeling in the redesign process leads to “continuous”

incremental improvements in product performance. Incremental benefits are

not realized once, but are continually realized each time the system is

redesigned.

Ford estimates that

using simulation

modeling for

ignition system

redesign leads to a

reduction of one

iteration in the

redesign process

and that each

iteration requires

40 percent of four

design engineers’

time over a 2.5-

month period.
Benefit Analysis of IGBT Power Device Simulation Modeling

5-6

Table 5-2. Benefits—IGBT Modeling Cost Reductions for Automotive Design Application

R&D cycle time is reduced by 1 to 2.5 months.

Product

Segment

Year

First

Used

Number of

IGBT Modeling

Activities per

Year

Reduced R&D

Cycle Time per

Modeling

Activity

Number of Engineers

(and share of time)

Involved in the

Design Task

Material Savings

per Design

Activity

Automobile

(Ford) ignition

systems

1991 Two redesigns 2.5 months 4 engineers

(40%)

Negligible

because used for

redesign activities

Automobile

(Ford) electric

vehicles

1993 1 1 month 3 engineers (100%) Negligible

Because simulation modeling has been used for redesign (as

opposed to initial design) Ford said that material cost savings in the

system design process have been negligible. However, if

simulation modeling had been available for basic design

development of the electronic ignition system, this would have led

to significant material cost savings through reductions in the

number of physical prototypes constructed.

Even though simulation modeling reduces R&D cycle time, Ford

said that it is not likely to result in an acceleration of product

development. Product development cycle time is primarily driven

by retooling production lines to meet new engine design

specifications.

Ford’s electric vehicle research division also uses simulation

modeling of IGBTs as part of its design process. A summary of the

benefits associated with the simulation modeling of IGBTs for

electric vehicles is also presented in Table 5-2. Ford began using

SABER in its electric vehicle research in 1993 and estimates that it

reduces a typical 8-month, three-person IGBT modeling task by

about 1 month.

However, Ford’s electric vehicle research division did not think that

using simulation modeling led to material cost savings through

fewer prototypes. Because the models they are working with are

not available in component libraries, Ford must develop

experimental models that require verification by physical

prototypes. In the future, as component libraries expand, material

cost savings in the design process may be realized.

Ford began using

SABER in its electric

vehicle research in

1993 and estimates

that it reduces a

typical 8-month,

three-person IGBT

modeling task by

about 1 month.
Section 5 — Analysis Results

5-7

Ford’s ignition system and electric vehicle research are conducted

in separate divisions and have independent overhead modeling

costs. Both divisions indicated that fixed overhead costs associated

with simulation modeling are large. Table 5-3 shows a summary of

overhead costs to support simulation modeling. These costs

include SABER licenses, annual software maintenance fees per

license, component library lease fees, and employee training.

However, Ford’s electric vehicle division indicated that they do not

have any full-time SABER support staff.

Table 5-3. Research Facility-Level Modeling User Costs for the Automobile Design Application

Companies typically maintain several SABER licenses; however, only 5 percent of SABER activities are related to IGBT

modeling.

Product Segment

Year

Purchased

Software

Number of

SABER

Licenses

Training for

Engineers

SABER

Support

Staff

Percent of

SABER Activities

Related to IGBT

Modeling

Automobiles

ignition systems

1991 6 2 modeling engineers

per year attending 5-

day course

2.5 fulltime staff5 percent

Automobiles

electric vehicles

1993 3 2 modeling engineers

5 days per year (no

formal course)

None 5 percent

SABER is used throughout the automobile design process, and Ford

estimates that only 5 percent of SABER activities are related to IGBT

modeling. Thus, annual IGBT modeling user costs are assumed to

be only 5 percent of the total modeling user costs associated with

supporting SABER.

Motor Controls. Motor controls are used primarily in ASDs for

industry, HVAC applications, and switching components that are

used in industrial programmable logic controllers (PLCs). PLCs are

used to control robotic assembly lines and other mechanical

processes driven by electronic feedback from sensors.

We conducted technical interviews with modeling engineers at

General Electric, Rockwell Automation/Allen Bradley Company,

and Eton Electronics. Three of the four motor control modeling

engineers interviewed indicated that they use simulation modeling

of IGBTs in designing their ASDs and that SABER was the primary
Benefit Analysis of IGBT Power Device Simulation Modeling

5-8

modeling software they use. One engineer indicated that they also

use PSPICE for some simple or quick-turnaround design tasks.

The fourth motor control modeling engineer interviewed indicated

that they did not use simulation modeling at their laboratory, but

that SABER is being used for IGBT modeling in a different division

within their company. He indicated that their division had

considered purchasing SABER a few years ago. However, the

company decided that the benefits of simulation modeling did not

justify the large software and training costs. This facility uses about

20 different IGBT devices in their ASDs. As an alternative to

simulation modeling, they conduct physical measurements of

switching rates and use these in designing their electronic systems.

They do use PSPICE to model some system parameters, such as

turnoff voltage spikes. However, at this point they have not used

PSPICE’s IGBT modeling capabilities.

The motor control companies that do use SABER for system design

typically do not develop the IGBT models themselves. They rely on

device manufacturers to supply the models, or they obtain them

from component libraries provided by Analogy (see Figure 3-1).

The models are then incorporated into the system simulation that is

conducted using SABER.2 If the IGBT modeling task is beyond

what is contained in Analogy’s component library, then they

contract modeling out to a modeling consultant, such as Sandia

Labs. Analogy provides a list of modeling consultants who support

SABER on their web site.

In general, any time simulation modeling is used in designing

motor controls, respondents said that at least one design iteration

can be eliminated. In some instances multiple iterations can be

eliminated. However, the use of simulation does add an additional

step early in the design process; thus, there is no significant change

in total product development cycle time.

Table 5-4 summarizes the benefits associated with using SABER to

model IGBTs as part of the new product design process for a typical

research facility. Benefits are identified separately for large and

small drive design activities. All the benefits identified during the

 2SABER models the entire system, including FET, resistors, etc. The IGBT model is

frequently a small part of the total system simulation model.

In general, any time

simulation modeling

is used in designing

motor controls,

respondents said

that at least one

design iteration can

be eliminated.
Section 5 — Analysis Results

5-9

Table 5-4. Benefits—IGBT Modeling Cost Reductions for Motor Control Applications (typical

research facility)

SABER was first used for motor control applications in 1993.

Product

Segment

Year

First

Used

Number of IGBT

Modeling

Activities per

Year

Reduced R&D

Cycle Time per

Modeling

Activity

Number of Engineers

(and Share of Time)

Involved in the

Design Task

Material Savings

per Design

Activity

Small drives 1993 2 4.5 months 1.5 engineers (100%) Could not estimate

Large drives 1993 1 9 months 2.3 engineers (100%) Could not estimate

interviews were from reductions in the number of labor hours

required to conduct the design process. Reductions in design time

ranged from 4.5 to 9 months, for two to three full-time engineers,

depending on the size of the drive. Most interviewees also

indicated that there were material savings from building fewer

physical prototypes, but that they could not estimate these cost

savings. As a result we have not included material costs savings

from the design process in our quantitative analysis.

An additional benefit mentioned during the interviews with motor

control modeling engineers is the reduction in the time and cost

required for final product testing in the simulation laboratory.

Simulation models allow engineers to conduct product debugging

in a virtual environment, thus reducing expensive simulation

laboratory time. However, respondents were not able to provide

information on associated cost savings or on the potential impact

on total product development cycle time.

The user costs associated with simulation modeling for a typical

large research facility are shown in Table 5-5. As with other

applications manufacturers, the primary costs are for the SABER

Table 5-5. IGBT Modeling User Costs for Motor Control Applications (typical research facility)

Fifty percent of SABER activities are related to IGBT modeling.

Product

Segment

Year

Purchased

Software

Number of

SABER

Licenses

Training for

Engineers

SABER

Support

Staff

Percent of SABER

Activities Related to

IGBT Modeling

Drives

(large and small)

1993 6 2 modeling engineers

per year attending 5-

day course

0.25 fulltime

modeler

50%
Benefit Analysis of IGBT Power Device Simulation Modeling

5-10

license, maintenance, and component libraries and for the time

required to develop the modeling skills to use SABER. User costs

include support for both large and small drive design activities.

Additional Applications

Simulation modeling of IGBTs is also used in designing products

such as compact fluorescent lights, power control equipment, and

electrotechnology equipment. The roles of IGBTs in these

applications are discussed in Section 2. As part of our discussions

with General Electric, we obtained information on the benefits and

costs of using simulation modeling in systems design for these

applications. General Electric indicated that in addition to using

SABER to conduct two to three motor control system designs per

years, they also typically use SABER to design one compact

fluorescent lighting system and one power control or

electrotechnology system per year. The benefits and costs

associated with these applications are presented in Tables 5-6

and 5-7, respectively.

Table 5-6. Benefits—IGBT Modeling User Cost Reductions for Additional Applications

Design engineers could not estimate material cost savings.

 Product Segment

Year

First

Used

Number of

IGBT Modeling

Activities per

Year

Reduced

Time per

Modeling

Activity

Number of Engineers

(and Share of Time)

Involved in the

Design Task

Material Savings

per Iteration

Compact

fluorescent lights

1993 1 4.5 months 1.5 engineers (100%) Could not estimate

Power control/

electrotechnology

1993 1 9 months 2.3 engineers (100%) Could not estimate

General Electric indicated that approximately two SABER licenses

were dedicated to lighting applications and two SABER licenses

were dedicated to power control/electrotechnology applications. In

both cases IGBT simulation modeling accounted for about

50 percent of SABER activities.
Section 5 — Analysis Results

5-11

Table 5-7. IGBT Modeling Overhead Costs for Additional Applications

About 50 percent of SABER activities are related to IGBT modeling.

Product Segment

Year

Purchased

Software

Number of

SABER

Licenses

Training for

Engineers

SABER

Support

Staff

Percent of SABER

Activities Related to

IGBT Modeling

Compact

fluorescent lights

1993 2 1 modeling engineer

per year attending 5-

day course

0.25 fulltime

modeler

50%

Power control/

electrotechnology

1993 2 1 modeling engineer

per year attending 5-

day course

0.25 fulltime

modeler

50%

5.3.2 Transaction Cost Impacts

SABER is also used by device manufacturers to generate datasheets

for each new family of IGBTs developed. Datasheets provide

information to applications manufacturers on the performance of

individual devices. Datasheets enable the comparison of similar

devices across device manufacturers and make publicly available

device characteristics needed to support simulation modeling.

The use of SABER for simulation modeling of IGBTs reduces the

time needed to develop product datasheets from about 1 month to

1 week (for one full-time design engineer). Without simulation

modeling, design engineers would have to conduct hundreds of

measurement tests per datasheet to manually plot out behavioral

curves. Now they use simulation modeling to predict IGBT device

behavior and only need to test a few points to verify the simulated

behavioral curves. Harris Semiconductors indicated that they

typically introduce one to two new families of IGBTs per year.

Each family typically contains six device sizes, two switching

speeds, and three package configurations, resulting in 36 different

devices (6x2x3). For each of these 36 devices, separate datasheets

are developed.

International Rectifier (IR) plans to begin using SABER for

generating datasheets in 1999. IR typically generates about 30

datasheets per year. Tables 5-8 and 5-9 provide a summary of

benefits and costs, respectively, for Harris Semiconductors and IR.

Both Harris Semiconductors and IR indicated that the overhead

costs associated with SABER were large. These costs include

The use of SABER

for simulation

modeling of IGBTs

reduces the time

needed to develop

product datasheets

from about 1 month

to 1 week.
Benefit Analysis of IGBT Power Device Simulation Modeling

5-12

Table 5-8. Benefits for Device Manufacturers

Three weeks of person hours are saved for each datasheet.

Device Manufacture

Year First

Used

Number of Data

Sheets per Year

Time Reduction

per Datasheet

Number of Engineers (and

Share of Time) Involved)

Harris Semiconductors 1998 36 3 weeks 1 engineer (100%)

IR 1999 30 3 weeks 1 engineer (100%)

Table 5-9. Overhead Costs for Device Manufacturers

SABER was not used to develop datasheets until 1998.

Device

Manufacture

Year

Purchased

Software

Number of

SABER

Licenses

Training for

Engineers

SABER

Support

Staff

Percent of

SABER Activities

Related to IGBT

Modeling

Harris

Semiconductors

1997 4 2 modeling engineers

per year attending 5-

day course

1 half-time

staff

100%—1 license

25%—3 licenses

IR 1998 1 1 modeling engineer

attending 5-day

course

1—25% of

time

100%

software license costs, maintenance fees, component library fees,

and staff training costs.

Harris Semiconductors maintains four SABER licenses. One model

is used full time by one IGBT modeling specialist who provides

modeling support. The other three licenses are used approximately

25 percent of the time for IGBT-related modeling activities by

design engineers. IR maintains one SABER license and uses it

exclusively for simulation modeling of IGBTs. The percentage of

SABER activities related to IGBT modeling will be used to estimate

Area D′ in part (b) of Figure 4-1.

5.3.3 Production Costs and Product Quality/Performance

Impacts

All of the modeling and design engineers interviewed said that

simulation modeling leads to improved performance of the final

product employing the IGBT device. However, no one was able to
Section 5 — Analysis Results

5-13

provide an accurate estimate of the magnitude of these impacts. In

addition, most contacts said that the use of simulation modeling

leads to material savings in the production process. However, they

also could not quantify these savings.

Automotive Industry

Ford engineers indicated that IGBT simulation modeling in the

ignition system has had an impact on automobile manufacturing

costs and performance. One modeling engineer stated that the

main benefit from IGBT simulation modeling was an increase in

system reliability. Decreasing defective components can lead to

substantial savings given production levels of 20 to 40 million units

per year. Defect screening is conducted during the manufacturing

process. Simulation modeling allows most reliability issues to be

addressed before components go to manufacturing. However,

respondents were not able to provide estimates of changes in defect

rates due to simulation modeling.

In addition, Hefner’s model can be used by product design

engineers to minimize the use of materials (such as silicon) given

the model’s superior predictive capabilities. However, respondents

were skeptical if this was actually being done because design

engineers typically use preset performance specifications for the

system including the IGBT.

Ford modeling engineers also stated that simulation modeling of the

ignition system can have a significant impact on automobile fuel

efficiency. It is commonly agreed that the introduction of the

electronic ignition system increased fuel efficiency by about

5 percent (Liu, 1998). Ford modeling engineers said that simulation

models of the ignition system can affect the performance of

electronic ignition systems by an additional 20 percent. IGBT

modeling accounts for approximately 5 percent of ignition system

modeling activities. Based on this information, one estimate of
Benefit Analysis of IGBT Power Device Simulation Modeling

5-14

simulation modeling of IGBTs’ potential impact is a 0.05 percent

increase in fuel efficiency.3

The potential economic impact from very small changes in

automobile fuel efficiency is large. National Highway Statistics

from the Department of Transportation indicate that fuel

expenditures for cars and motorcycles in 1995 were approximately

$67 billion (DOT, 1998). If we assume that IGBT modeling has a

0.05 percent impact on fuel efficiency, we estimate an annual

reduction in fuel expenditures of $33.5 million. This impact should

be viewed as an upper-bound estimate of the fuel efficiency

benefits from IGBT simulation modeling because the modeling

engineers interviewed at Ford were uncertain about the extent to

which simulation modeling results were being used throughout the

design process.4

For electric vehicles, Ford engineers indicated that simulation

modeling of IGBTs has led to significant decreases in engine costs.

The precision of Hefner’s Model allows designers to lower safety

factors, sometimes from 20 to 50 percent. This safety factor

reduction decreases material costs for silicon and heat sinks and

has resulted in a 10 percent reduction in the cost of inverters for

electric engine drives. Inverter costs for electric engines typically

range from $500 to $1,000. Thus, simulation modeling of IGBTs

has led to a $50 to $100 materials cost reduction per vehicle. At

the current production rates of only a few hundred vehicles per

year, the aggregate savings is relatively small. But as electric

vehicles move to mass production the aggregate economic benefit

could potentially be significant.

 3The example of 0.05 percent increase in fuel efficiency is based on information

provided by Ford, assuming simulation modeling is used to its full advantage

throughout the design process. If electronic ignition systems increased fuel

efficiency by 5 percent, simulation modeling increases the performance of the

ignition system by an additional 20 percent, and IGBT modeling accounts for

approximately 5 percent of simulation activities, then multiplying these

percentages together yields a 0.05 percent impact on fuel efficiency.

4Ford modeling engineers said that, if used properly, simulation models can lead

to significant design improvements. However, the impact of simulation

modeling on fuel efficiency depends on how the design engineer uses the

modeling results. It is suspected that some downstream design engineers do

not use the “simulation” capabilities of the model in the overall ignition system

design. They either ignore the model and just make a few modifications to

previous component designs, or they conform strictly to the simulated

performance parameters and do not take advantage of alternative design

options.

The potential

economic impact

from very small

changes in

automobile fuel

efficiency is large.

Typically systems are “over

designed,” providing a

safety factor to account for

uncertainties in the design

process. The increased

precision of simulation

modeling enables designers

to reduce safety factors.
Section 5 — Analysis Results

5-15

Motor Controls

Our technical interviews indicate that simulation modeling of

IGBTs in the system design of motor controls has led to increased

product performance for industrial and HVAC drive applications.

However, none of the modeling engineers involved in drive design

that we interviewed could quantify these benefits. Because drives

are used in such a wide range of products, such as compressors for

air conditioners, air circulation systems, industrial conveyer belts,

and controls for robotics, modeling engineers could not assess the

impact that increased drive performance would have on metrics

such as energy consumption.

All of the modeling engineers interviewed said that using

simulation modeling increases the switching efficiency of the drive,

which leads to more precise motor control. In addition, modeling

engineers indicated that using simulation modeling reduces waste

heat generated by the drive. This lowers the energy consumption of

the drive itself and reduces material costs associated with heat sinks

used to dissipate waste heat.

Even though the incremental impact of simulation modeling of

drive performance may be small, the economic benefits associated

with these small increases in drive performance are potentially very

large. Table 5-10 lists major motor-driven end uses, estimates of

their share of national electrical energy consumption, and the

potential energy savings associated with motor controls. Electrical

energy consumption in 1996 was 3,114,894 MWhs, representing

expenditures of approximately $214 billion (DOE, 1997).

Assuming that the penetration of ASDs has reached approximately

half of its potential identified in Table 5-10, energy savings

associated with ASDs is $11.6 billion. Then, for example, if using

simulation modeling led to a 0.05 percent increase in efficiency,

the annual economic benefit to society would be $5.8 million.5

 5$214 billion x 57.1 percent x (19/2) percent x 0.05 percent = $5.8 million. The

0.05 percent increase in efficiency is provided as an example; this value is not

based on information collected during the surveys of motor control

applications manufacturers.

All of the modeling

engineers

interviewed said

that using

simulation modeling

increases the

switching efficiency

of the drive, which

leads to more

precise motor

control.
Benefit Analysis of IGBT Power Device Simulation Modeling

5-16

Table 5-10. Estimated Motor Electricity Usage and Potential ASD Savings

The end uses shown in this table account for 57.1 percent of total electrical energy usage in the U.S. The use of ASDs

could potentially reduce usage associated with these end uses by 19 percent. For example, refrigeration consumes

6.9 percent of electricity usage in the U.S. The use of ASDs can reduce refrigeration energy usage by 20 percent.

Sector End-Use

Electrical Usage

 as a Percent of

Total U.S. Usage for

Selected End Uses

Potential ASD Savings

in Terms of Reduction

in Energy Usage by

End-Use Percent

Residential Refrigeration 6.9 20

Space Heating 1.4 25

Air Conditioning 3.8 20

Other 0.9 0

Residential Total 13.1 19

Commercial Air Conditioning 7.5 15

Ventilation 2.2 25

Refrigeration 1.3 25

Other 0.1 20

Commercial Total 11.3 18

Industrial Pumps 7.7 25

Blowers and Fans 4.5 25

Compressors 3.9 25

Machine Tools 2.1 10

Other Integral HP 2.8 0

DC Drives 2.5 15

Fractional HP 1.1 0

HVAC 0.6 15

Industrial Total 25.4 18

Public and miscellaneous Municipal Water Works 1.7 15

Electric Utilities 5.4 25

Other 0.2 0

Public and Miscellaneous Total 7.3 22

Totals 57.1 19

Source: de Almeida, Anibal T., Steve Greenberg, and Carl Blumstein. 1990. “Demand-Side Management

Opportunities through the Use of Energy-Efficiency Motor Systems.” IEEE Transactions on Power Systems

5(3):852-861.
Section 5 — Analysis Results

5-17

Additional Applications

As with automobile and motor control applications, industry

experts indicated that simulation modeling of IGBTs in the system

design process can lead to increased product performance for

compact fluorescent lighting, power control, and electrotechnology

applications. Even though the industry experts interviewed could

not quantify the increased product performance, the following

examples provide insight into the potential magnitude of these

benefits.

IGBTs are used in high-efficiency electronic ballasts in compact

fluorescent lamps. The use of high efficiency ballasts in compact

fluorescent lamps has the potential to reduce total annual U.S.

electrical energy consumption by approximately 0.75 percent, or

$1.6 billion. These reduction estimates are based on the following

information:

Z total annual U.S. electrical energy expenditures in 1996 =

$216 billion (DOE, 1997)

Z lighting accounts for approximately 25 percent of energy

consumption (Jednacz, 1991b)

Z compact fluorescents have the potential to account for

20 percent of lighting applications (Mitchell, 1998)

Z high-efficiency electronic ballasts in compact fluorescents

can reduce energy consumption by 15 percent (compared

to incandescent lamps) (Neilsen, 1993).

Z percent reduction = 25 percent x 20 percent x 15 percent =

0.75 percent

Z energy expenditure reduction = $212 billion x 0.75 percent

= $1.6 billion.

Thus, if using simulation modeling in designing electronic ballasts

leads to, for example, a 0.01 percent increase in ballast

performance, this could result in a $0.16 million reduction in

annual energy expenditures.

As a second example, several industry experts indicated that

simulation modeling of IGBTs in the system design process leads to

a reduction in the size and number of capacitors needed for power

conditioning equipment. Power conditioning equipment is a major

end user of capacitors, and annual sales of capacitors in 1994 were

$1.9 billion (1996 Electronic Market Data Book). As a result, small

The use of high

efficiency ballasts in

compact fluorescent

lamps has the

potential to reduce

total annual U.S.

electrical energy

consumption by

approximately

0.75 percent, or

$1.6 billion.
Benefit Analysis of IGBT Power Device Simulation Modeling

5-18

changes in the size and number of capacitors needed for power

conditioning applications can lead to significant economic benefits.

5.4 AGGREGATE DESIGN IMPACTS

Our approach to estimating benefits is to include only clearly

identifiable and quantifiable impacts in the quantitative analysis.

Table 5-11 shows the benefit categories included in the quantitative

analysis.

Table 5-11. Economic Sectors and Related Benefit Categories

The categories identified with an X were included in the quantitative analysis. The categories identified with a X were

evaluated qualitatively.

Sectors

R&D

Efficiency

Transaction

Costs

Production

Costs

Product

Quality

Software companies X

Device manufacturers X

Applications manufacturers X X X

End users X

Quantified benefits are derived from the use of SABER by device

manufacturers to generate datasheets and by applications

manufacturers to simulate IGBTs in the system design process.

Benefits are defined as the difference between labor savings from

using simulation modeling of IGBTs and user costs to support

SABER activities related to IGBTs.

The impacts described in Section 5.3.1 provide the basis for

estimating research facility-level benefits and costs associated with

simulation modeling of IGBTs. Research facility-level benefits and

costs are used to calculate net research facility-level benefits

(benefits net of user costs). Net research facility-level benefits are

then weighted to obtain national benefits.

As indicated in Table 5-11, we have not quantitatively included

benefits from improved product performance in our estimate of

total benefits. As described in Section 5.3, the impact of simulation

modeling in this area has potentially generated significant benefits

to society. However, because of difficulty in obtaining reliable
Section 5 — Analysis Results

5-19

information on the magnitude of these impacts we have not

included these potential benefit in the estimate of total benefits

calculated below or in the benefit-cost ratio or social rate of return

to the NIST program presented in Section 5.6. Thus, our economic

impact estimate associated with NIST’s contributions may be

considered a conservative estimate.

In addition, R&D efficiency gains to software companies were not

directly quantified. NIST’s contributions to IGBT simulation

modeling lowered R&D costs for software companies, leading

potentially to

Z increased profits for software companies and

Z lower software prices for device and applications

manufacturers.

Benefits associated will lower software prices are captured in our

quantitative analysis through lower user costs for device and

applications manufacturers. However, increased profits to software

companies are not included in the quantitative analysis.

5.4.1 Research Facility-Level Benefits

Research facility-level benefits associated with simulation modeling

include the decrease in R&D labor costs, less the user costs to

support modeling software. Material cost reductions in the system

design process (such as fewer physical prototypes) are not included

in benefits estimates because modeling engineers either indicated

that there were no material costs savings or that the savings could

not be identified.

The benefits and costs included in the quantitative analysis are

based on the use of Analogy’s software product SABER. All of the

benefits and costs identified by the modeling engineers in the

technical interviews were directly related to using SABER for

simulating IGBTs’ behavior. Whereas some engineers said they do

occasionally use PSPICE for simple or quick-turnaround modeling

activities, they did not think that the benefits of Hefner’s Model

were realized during the use of PSPICE.

The following economic information was obtained during the

technical interviews and used in the calculation of research facilitylevel benefits:

Z Initial SABER license is $50,000.
Benefit Analysis of IGBT Power Device Simulation Modeling

5-20

Z Each additional SABER license is $30,000.

Z Annual maintenance fee is 12 percent of total license costs.

Z Annual lease fee for components library is $5,000.

Z SABER prices (nominal) have remained constant over the

past 8 years.

Z Design engineer’s fully loaded (including fringe benefits

plus overhead) salary is $100/hr (1998 dollars).

Z SABER modeling engineer’s (modeling support staff’s) fully

loaded salary plus fringe benefits is $125/hr (1998 dollars).

A spreadsheet model was used to calculate the NPV of benefits and

costs. A real social discount factor of 7 percent was used to

discount cash flows (OMB, 1995). Because the social discount

factor of 7 percent is a real discount factor, all benefits and costs

were adjusted to 1998 dollars prior to discounting. Benefits and

costs were projected through the year 2003.6

For applications manufacturers, benefits and costs were calculated

at the research-facility level using the information on typical

research facilities presented in Section 5.3. For device

manufacturers, benefits per datasheet were estimated and scaled to

represent a typical device manufacturer. From surveys and

company web sites, the typical number of datasheets generated

annually by a device manufacturer was estimated to be 20.25.7

Research facility-level labor savings, SABER user costs, and net

benefits estimates are shown in Table 5-12. Estimates are presented

by industry segment and represent impacts for a typical research

facility. Both the labor savings and SABER overhead costs are

largest for a typical drive research facility because of the large

 6Projecting benefits 5 years into the future will provide a conservative (lowerbound) estimate of total benefits. Professor Peter Lauritzen (1998) indicated

that during the 1990s Hefner’s model has been widely accepted as the standard

for IGBT modeling and that it is currently at its peak of “significance.” He

noted that enhanced models (still based on NIST’s core algorithm) are currently

being developed. However, it is likely to take several years for new models to

be verified and incorporated into commercially available software packages,

implying that NIST’s existing models in SABER will continue to represent

significant advantages over alternative design processes for several years in the

future.

7Included were Harris Corporation (36 IGBT datasheets per year), IR (30 IGBT

datasheets per year), Motorola Incorporated (10 IGBT datasheets per year), and

Delco (5 IGBT datasheets per year). The number of IGBT datasheets per year

was obtained through the technical interviews with modeling engineers for

Harris Corporation and IR and was estimated from product offerings for

Motorola Incorporated and Delco.
Section 5 — Analysis Results

5-21

Table 5-12. Estimated Benefits and Costs to Industry from Simulation Modeling of IGBTs in the

System Design Process

Motor control applications account for 63 percent of estimated benefits.

Industry Segment

Research

FacilityLevel Labor

Savings

(thousands,

$1998)

Research

Facility-Level

SABER User

Costs

(thousands,

$1998)

Net

Research

Facility-Level

Benefits

(thousands,

$1998)

Weight to

Obtain

National

Benefits

National

Benefits

(thousands,

$1998)

Device manufacturers 438 112 325 4 1,301

Automotive ignition

systems

713 197 516 3 1,547

Automotive electric

vehicles

209 13 196 3 588

Motor control 2,388 216 2,172 5 10,859

Lighting 471 108 363 1 363

Power control 1,445 108 1,337 2 2,675

Benefits 17,334

number of design activities conducted annually at these

laboratories that involve IGBT simulation modeling.

5.4.2 Weighting Research Facility-Level Benefits to

National Benefits

We used weights to scale research facility-level benefits to obtain

national-level benefits. Weights were developed separately for

different industry segments. The weights are based on the number

of research facilities that were identified to be using SABER for

IGBT modeling.8

For the automotive industry, Ford’s research facility-level benefits

were multiplied by three because Ford indicated that both GM and

Chrysler were also using SABER to conduct simulation modeling of

IGBTs in the design of their ignition systems and electric vehicles

and that their benefits and costs would be similar.

 8These weights are likely to be conservative because it is possible that additional

companies within these industries are using SABER for IGBT modeling.

However, we included in the weights only companies verified during our

telephone surveys.
Benefit Analysis of IGBT Power Device Simulation Modeling

5-22

The weight for device manufacturers was developed based on the

number of U.S. companies using SABER to generate datasheets.

Analogy identified four U.S. device manufacturers that use SABER:

Harris Corporation, IR, Motorola Incorporated, and Delco

Electronics.

Weights for motor control, lighting, and power conditioning

applications manufacturers’ research facility-level benefits were

developed with the help of Analogy. As shown in Tables 2-4

through 2-6, five motor control, two power control, and one

lighting research facility hold SABER licenses.

5.4.3 Net Benefits to Industry

Table 5-12 also presents national benefit estimates. The net

benefits to industry associated with IGBT simulation modeling are

estimated to be approximately $17 million. Seventeen million

dollars reflects the sum of the discounted flow of benefit net of cost

from 1985 to 2003, presented in 1998 dollars. Benefits and costs

by year are presented in Table 5-13.

The most influential factors in determining the magnitude of

benefits and costs are highlighted below:

Z The reduced design time and the number of modeling and

design engineers involved in the task were important

determinants of benefits. This provided the basic building

block for estimating benefits.

Z The number of activities conducted per year (new product

designs or datasheet development) was also an important

determinant of benefits. In particular, for device

manufacturers, the large number of datasheets developed

per year lead to large benefits even though the time savings

per datasheet were relatively small.

Z The number of full-time support staff for SABER modeling

was the largest contributor to user costs. The main

distinction between costs for automobile ignition systems

and electric vehicles is that Ford’s ignition system division

reported having 2.5 full-time SABER modelers to assist

design engineers, whereas Ford’s electrical vehicle division

said they had no SABER modeling support.

Z The percentage of SABER activities related to IGBT

simulation modeling greatly influenced overhead cost

estimates. Total software and modeling support staff costs

associated with SABER were typically quite large.

However, because IGBT simulation is just one of SABER’s

many simulation components, only a fraction of SABER
Section 5 — Analysis Results

5-23

Table 5-13. Net Benefits Generated by Industry—by Industry Group and Year ($thousand 1998)

For most companies benefits were not generated in the year in which SABER was purchased. Thus, the net benefits

generated by industries in the initial year are negative.

Year

Auto—

Ignition

Systems

Auto—

Electric

Vehicles

Drives

(GE)

Device

Manufacturers Lighting

Power

Controls

Total Net

Benefits to

Industry

1985 (beginning) 0 0 0 0 0 0 0

1985 (end) 0 0 0 0 0 0 0

1986 0 0 0 0 0 0 0

1987 0 0 0 0 0 0 0

1988 0 0 0 0 0 0 0

1989 0 0 0 0 0 0 0

1990 -130 0 0 0 0 0 -130

1991 293 0 0 0 0 0 293

1992 293 -26 -645 0 -65 -129 -571

1993 293 138 2,567 0 91 629 3,718

1994 293 138 2,569 0 91 629 3,720

1995 293 138 2,571 0 91 629 3,723

1996 293 138 2,572 0 92 630 3,725

1997 294 138 2,574 -163 92 630 3,565

1998 294 138 2,576 286 92 630 4,016

1999 294 138 2,577 790 92 631 4,522

2000 294 138 2,579 791 92 631 4,525

2001 294 139 2,580 791 92 631 4,528

2002 294 139 2,582 792 93 632 4,530

2003 294 139 2,583 793 93 632 4,533

NPV

t=0 1985 beginning

t=1 1985 end

1,547 588 10,859 1,301 363 2,675 17,334

overhead costs were attributed to simulation modeling of

IGBTs. For example, Ford modeling engineers (both in

ignition systems and electric vehicles) said that the share of

SABER modeling activities involving IGBT simulation was

5 percent. When this is applied to total SABER overheads,

costs are significantly reduced.
Benefit Analysis of IGBT Power Device Simulation Modeling

5-24

5.5 INDUSTRIES’ ASSESSMENT OF NIST’S

CONTRIBUTIONS AND NIST’S SHARE OF

TOTAL BENEFITS

To estimate benefit-cost ratios or the social rate of return to the

NIST program, we need to determine what share of the total

benefits estimated in Section 5.3 should be attributed to NIST’s

contributions. Although NIST was the sole developer of the

mathematical modeling algorithms, several parties were involved in

model verification and incorporating the model into SABER to make

it available to device and applications manufacturers. The primary

parties involved were NIST, Analogy, industry end-users such as

Ford, and device manufacturers such as Harris Semiconductors and

Motorola.

For example, NIST and Ford Motor Company worked together

closely for several years to verify the mathematical models and

support Analogy’s efforts to incorporate these models into SABER.

In addition, NIST participated in a Cooperative Research and

Development Agreement (CRDA) with Ford, Motorola, and Harris

Semiconductor to transfer parameter extraction technology to

private industry. The extraction hardware and procedures

developed by NIST are an essential part of simulation modeling

because they are used to generate the input parameters for the

SABER simulations.

Ford may have pursued the development of IGBT simulation

capabilities (including parameter extraction) in the absence of

NIST, possibly developing in-house models. However, the resulting

models would not have been as accurate, leading to lower benefits,

and hence would not have penetrated the market as quickly as the

simulation software using NIST’s mathematical models (Perry,

1998).

To reflect contributions from Ford and other industry end users of

simulation modeling, it is likely that NIST’s share of total benefits

estimated in Section 5.3 is approximately 60 percent. This

estimated percentage is based on discussions with technical experts

in the industries involved in the collaborations. However, because

of the importance (and uncertainty) of this percentage, we present a

range of benefit-cost ratios and social rate of returns to the NIST

program, varying NIST’s share of total benefits from 40 percent to

80 percent. Again, based on discussions with industry experts, it

Because of the importance

and uncertainty of NIST’s

share of total benefits, we

present a range of benefitcost ratios and social rate

of returns to the NIST

program, varying NIST’s

share of total benefits from

40 percent to 80 percent.
Section 5 — Analysis Results

5-25

was determined that NIST’s share of benefits was probably not

greater than 80 percent or less than 40 percent. For example, one

industry expert stated that NIST has had “a significant impact” and

credited NIST with “accelerating the development of SABER for

IGBTs.” Upper-level management at Analogy stated that “without

NIST’s contributions Analogy would have developed an IGBT

model, but it would not have been nearly as good.” However, a

few industry experts were sensitive about giving NIST the majority

of the credit, pointing out that many other device and applications

manufacturers “contributed to getting the model up and running.”

5.6 NIST’S PROGRAM COSTS

In 1985 NIST began development of a mathematical model for

IGBT devices that simulates their performance. This model was

introduced in commercial simulation software packages in 1990.

Tables 5-14a and 5-14b show actual and inflation adjusted annual

NIST program expenditures related to developing and promoting

simulation modeling for IGBT power devices. Future program costs

are expected to continue through the year 2000 at current

expenditure levels (Hefner, 1998).

The NPV of NIST’s program expenditures in 1998 dollars is

$447,000. Labor costs are fully loaded and include fringe benefits

and overhead costs. Discounted program expenditures are given

by

Discounted Expenditures = ∑

i=0

n Ct+i

(1+r)i (5.1)

where

C = real ($1998) expenditures in year (t+i), including labor,

equipment and miscellaneous costs

r = real social discount rate of 7 percent

t = base year 1984

i = 0 corresponds to the beginning of 1985

i = 1 corresponds to the end of 1985 (expenditures

occurred from 1/85 to 12/85)

n = 19 (through year 2003)
Benefit Analysis of IGBT Power Device Simulation Modeling

5-26

Table 5-14a. Actual NIST Program (Nominal) Expenditures by Year

Labor accounted for the majority of NIST’s expenditures.

Fiscal Year

Labor

($thousands)

Equipment

($thousands)

Misc. Costs

($thousands)

Total

($thousands)

1985 (beginning) 0 0 0 0

1985 (end) 5 0 1 6

1986 9 0 1 10

1987 10 0 1 11

1988 24 0 2 26

1989 35 0 2 37

1990 47 0 3 50

1991 96 16 5 115

1992 68 25 3 96

1993 69 17 3 89

1994 32 25 2 89

1995 32 13 2 50

1996 16 0 1 17

1997 19 0 1 20

1998 20 0 1 21

1999 20 0 1 21

2000 20 0 1 21

2001 0 0 0 0

2002 0 0 0 0

2003 0 0 0 0
Section 5 — Analysis Results

5-27

Table 5-14b. Inflation Adjusted NIST Program (Real) Expenditures by Year ($thousands 1998)

Labor accounted for the majority of NIST’s expenditures.

Fiscal Year Inflation Index (CPI) Labor Equipment Misc. Costs Total

1985 (beginning) 0.647 0 0 0 0

1985 (end) 0.647 8 0 2 9

1986 0.659 14 0 2 15

1987 0.683 15 0 1 16

1988 0.711 34 0 3 37

1989 0.745 46 0 3 49

1990 0.785 60 0 4 64

1991 0.819 117 20 6 143

1992 0.843 80 30 4 113

1993 0.868 79 20 3 102

1994 0.891 35 28 2 66

1995 0.916 35 14 2 51

1996 0.943 17 0 1 18

1997 0.971 20 0 1 21

1998 1.000 20 0 1 21

1999 1.030 19 0 1 20

2000 1.061 18 0 1 19

2001 1.093 0 0 0 0

2002 1.126 0 0 0 0

2003 1.159 0 0 0 0

NPV

t=0 1985 beginning

t=1 1985 end

363 61 23 447
Benefit Analysis of IGBT Power Device Simulation Modeling

5-28

5.7 BENEFIT-COST RATIO AND SOCIAL RATE OF

RETURN FROM THE NIST PROGRAM

We used the NPV estimates of total benefits attributable to NIST

and NIST’s program expenditures to develop three measures of

economic return from the NIST program—the NPV, the benefit-cost

ratio, and the social rate of return.

The NPV of the NIST simulation modeling program is given by

NIST NPV = 





























 Discounted  Benefits to

 Industry

× 

 

NIST’s Share – 

Discounted 

NIST

Expenditures

(5.2)

6.5 = 17.3 × 0.4 – 0.45

13.4 = 17.3 × 0.8 – 0.45

NIST NPV ranges from $6.5 million to $13.4 million (1998 dollars).

The benefit-cost ratio is given by

Benefit-Cost Ratio = 

Discounted Benefits to 

Industry x NIST’s Share

Discounted NIST Expenditures (5.3)

15.5 = 

17.3 × 0.4

0.45

31.0 = 

17.3 × 0.8

0.45

The estimated benefit-cost ratio for the NIST program ranges from

15.5 to 31.0 for the two scenarios of NIST’s share of benefits being

40 percent and 80 percent. The social rate of return is the discount

rate where the NIST NPV equals zero. Thus, r is determined by

solving the following equation for r.

∑

i=0

n

 







 B(t+i)

(1+r)i x NIST’s Share – ∑

i=0

n









 Ct+i 

(1+r)i = 0 (5.4)

The estimated social rate of return for the NIST program is

67.4 percent for the scenario where NIST’s share of total benefits is

40 percent. For the scenario where NIST’s share of benefits is

80 percent, the social rate of return is 85.6 percent.
6-1

Market Barriers and 6 the Role of NIST

NIST’s contributions have helped lower market barriers to the

development and adoption of IGBT simulation modeling software

and have led to significant social benefits. IGBT simulation

modeling advances initiated by NIST and private industry primarily

for modeling automobile ignition systems have generated

significant spillovers in applications such as motor controls, power

conditioning equipment, electrotechnologies, and lighting. These

benefits flow to society through improved performance of final

products employing IGBTs and through lower R&D costs.

The use of IGBT simulation modeling is still gaining momentum

and will continue to expand into new product areas. Many

applications manufacturers are in the process of adopting IGBT

simulation modeling, and these additional benefits will be realized

in the near future. Future penetration of IGBT simulation modeling

will be driven by factors such as the increasing complexity of

electrical systems and the spread of IGBTs into lower voltage

applications.

However, several barriers are limiting the adoption of and the

benefits generated from the use of IGBT simulation modeling.

Some of these barriers, such as software and training costs (pull

costs), are natural market factors that affect the evolution of most

new products. But other barriers seem to represent persistent

market failures and hence potential roles for the NIST program. For

example,

Z software companies do not have the technology base to

design full-function models and it is not in their strategic

market focus to develop these capabilities;

NIST’s contributions

have helped lower

market barriers to

the development

and adoption of

IGBT simulation

modeling software

and have led to

significant social

benefits.
Benefit Analysis of IGBT Power Device Simulation Modeling

6-2

Z spillovers occur in the form of technology’s use by firms or

industries that did not fund the underlying R&D, but are still

able to appropriate at least some of the resulting benefits;

Z network externalities are created as increasing numbers of

companies along the supply chain assimilate IGBT

modeling into their design process; and

Z network externalities are created as additional component

models (such as diodes) are added to simulation software.

This section focuses on barriers to the realization of economic

benefits from IGBT simulation modeling. Some of these barriers are

market failures that limit the development of modeling techniques

and software and the adoption of IGBT simulation modeling by

device and applications manufacturers. This section also describes

how NIST’s activities in this area have addressed these barriers and

how ongoing and potential future activities might lead to greater

economic benefits. The information presented in this section

reflects comments provided by industry experts during the

interviews.

6.1 BARRIERS TO THE DEVELOPMENT OF

SIMULATION MODELING SOFTWARE

PRODUCTS

Software companies and device and applications manufacturers

each cited unique factors that represented barriers to the

development of IGBT performance simulation modeling software

products. These factors include market barriers such as

nonappropriability and the cost of assembling multidisciplinary

teams to address the broad range of technical issues. Interviewees

also suggested that similar barriers affect the development of nonIGBT modeling components and that enhancements to non-IGBT

modeling components would increase the overall effectiveness of

simulation modeling in the system design process.

6.1.1 Barriers to the Development and Incorporation of

IGBT Modeling Capabilities into Simulation Software

Market barriers have contributed to the delay in the development of

IGBT capabilities in simulation modeling software. Different

barriers affect different segments of the IGBT simulation modeling

supply chain. For example, software companies, such as Analogy,

do not have the technology base to develop, verify, and implement

Several barriers are

limiting the

adoption of and the

benefits generated

from the use of

IGBT simulation

modeling.
Section 6 — Market Barriers and the Role of NIST

6-3

the required mathematical algorithms. Device manufacturers do

not have the in-house expertise to model how their devices will

interact with the systems in which they are incorporated.

Applications manufacturers in many instances have the technical

expertise to develop the mathematical algorithms and system

interactions, but they do not have the marketing infrastructure to be

able to appropriate the returns to these R&D activities. In general,

each segment of the chain possesses a subset of the capabilities

required to research, commercialize, and support IGBT simulation

modeling, but it is not in their strategic market focus to internally

develop the full spectrum of capabilities.

Analogy is a relatively small software company with limited

resources. It is not their strategic market focus to specialize in

theoretical modeling for the wide range of electrical components

supported by SABER. As a result, most simulation modeling

enhancements are initiated and supported by applications

manufacturers. However, it is difficult for individual (or groups of)

applications manufacturers to appropriate the returns to their

investments in simulation modeling capabilities because the

algorithms and techniques they develop will be widely used by

many other firms in many different industries. Because of the

presence of large spillover benefits, many simulation modeling

software enhancements that are in the best interest of society are

not pursued. Only the “killer applications” for which the returns to

individual software companies or device or applications

manufacturers (without appropriating spillovers) are sufficiently

large are developed and incorporated in the simulation modeling

software.

The development of commercially available software packages

such as SABER that incorporate IGBT simulation modeling

capabilities was largely driven by NIST and the automobile

industry. In this case, the “killer application” was the use of IGBT

modeling to support the design of electronic ignition systems.

Advances in ignition coils and federal mandates to increase fuel

efficiency provided the financial incentives for the automobile

industry to pursue the development of IGBT simulation modeling

capabilities.

Ford Motor Company and its device supplier Motorola made

important contributions to verifying and incorporating NIST’s

The “killer application”

motivating the

development of IGBT

modeling capabilities was

the introduction of IGBTs

in electronic ignition

systems.
Benefit Analysis of IGBT Power Device Simulation Modeling

6-4

mathematical models into SABER. In the process they generated

significant technology spillovers by making IGBT simulation tools

available to other applications manufacturers, such as

manufacturers of motor controls or power control equipment.

However, even with these relatively large financial incentives, Ford

and Analogy representatives indicated that without NIST’s

contributions the development of IGBT simulation modeling would

have been delayed or may not have been pursued after all. The

barriers to Analogy were the costs of assembling the

multidisciplinary team needed to develop and verify the models.

Barriers for Ford and Motorola were their inability to appropriate

the full returns from their R&D efforts because they did not have (or

desire to develop) the needed software marketing distribution

capabilities.

In addition, both Ford and Analogy indicated that SABER’s IGBT

modeling components would not have been as accurate without

NIST’s contributions. As a result, without NIST, the returns to

private investment would have been lower, and IGBT simulation

modeling capabilities might not have been developed.

NIST’s role in the development and incorporation of IGBT

simulation modeling capabilities into SABER was motivated by the

market barriers described above.

In addition, during interviews with applications manufacturers, we

identified a second example supporting the presence of barriers in

the software development area. Incorporating dynamic thermal

modeling capabilities into simulation modeling software was cited

as one of the most important issues facing modelers. Ford and

Motorola had been pursuing a joint venture to expand IGBT

dynamic thermal modeling beyond ignition components, which are

the existing capabilities in SABER. However, the joint venture,

which was estimated to be a relatively modest project with a

$10,000 budget, has failed to proceed because the individual

benefits to Ford or Motorola are relatively small, in part because

these modeling benefits would also be realized by other automobile

manufacturers also using SABER. Total benefits to society,

however, would be large because of significant spillover benefits.

The barriers described above also affect the development of nonIGBT component models. Industry experts emphasized that IGBT

Both Ford and

Analogy indicated

that SABER’s IGBT

modeling

components would

not have been as

accurate without

NIST’s

contributions.
Section 6 — Market Barriers and the Role of NIST

6-5

modeling is just one of many interrelated components used in the

overall simulation design process (Ford stated that only 5 percent of

SABER activities were associated with IGBT modeling). As a result,

network externalities are generated when IGBT and non-IGBT

modeling components are improved.

Several interviews indicated that existing simulation software

packages require enhancement of their non-IGBT component

models to fully realize the benefits of NIST’s mathematical models.

However, industry experts were not optimistic that these

enhancements would be incorporated in the near future if the

market is left to its own forces, again implying that market failures

were delaying incorporation of these enhancements. Section 6.2

discusses this issue in greater detail.

6.1.2 Competition in the IGBT Simulation Modeling

Software Market

Lack of competition in the simulation modeling software market

was mentioned by applications manufacturers as a potential barrier

limiting the incorporation of software enhancements. NIST’s

mathematical models are available in the public domain.

However, it is costly for software companies to incorporate these

mathematical models into their software products. Analogy and

OrCAD (formerly MicroSim) currently offer software products that

have incorporated NIST’s mathematical modeling—SABER and

PSPICE, respectively. Other simulation software suppliers, such as

Mentor Graphics, Intusoft, and Cadence, do not have IGBT

modeling capabilities.

Although SABER and PSPICE compete in the market for design tools

used in the design of products employing IGBTs, their competition

is limited because their markets are differentiated. SABER is widely

acknowledged as having superior IGBT modeling capabilities and is

the dominant software package used for detailed simulation

modeling of IGBTs. However, assimilation costs associated with

SABER are significant. For example, SABER is significantly more

expensive to purchase, learn, and support compared to PSPICE.

Many companies we spoke with indicated that they had full-time

programming staff dedicated to supporting SABER modeling.
Benefit Analysis of IGBT Power Device Simulation Modeling

6-6

In contrast, many versions of PSPICE are publicly available on the

Internet. PSPICE is simple to learn and is used by universities in

power electronic courses; thus, most design engineers have been

exposed to PSPICE as part of their academic education. As a result,

SABER and PSPICE each serve their respective niche markets and

compete only in the instances where device and applications

manufacturers are willing to sacrifice modeling capabilities for

lower modeling costs.

SABER’s near dominance in the market for advanced IGBT

simulation software does not necessarily indicate a market failure.

Alternatives to the use of SABER, such as the use of physical

prototypes in the design process, limit Analogy’s ability to extract

monopoly profits. In addition, given the relatively limited size of

the existing market for advanced IGBT simulation capabilities and

the cost of developing simulation software, it is unclear if the

market could support competing advanced simulation software

products. Also, in the future as IGBT applications expand into

lower voltage applications, it is likely that increased demand for

advanced IGBT modeling capabilities will stimulate entries into the

advanced simulation modeling software market.

However, some applications manufacturers thought that Analogy’s

use of a propriety modeling language for SABER limited

competition and hence increased Analogy’s software prices.

Device and applications manufacturers said that after developing a

new IGBT behavioral model they typically make the model publicly

available by either posting it on the Internet or including it in

Analogy’s component library. However, because the model has

been developed in MAST (SABER’s propriety underlying language),

it cannot be integrated into competing simulation packages such as

PSPICE.

IEEE has formed a committee to develop and promote a

standardized modeling language to make simulation modeling

component libraries more interoperable. However, at this point the

language is not advanced enough to accommodate many

simulation modeling activities. In addition, some applications

manufacturers indicated that this effort has received little support

from simulation software companies with strong market positions.

As a result, they were not optimistic that a standardized modeling

Although SABER

and PSPICE

compete in the

market for design

tools used in the

design of products

employing IGBTs,

their competition is

limited because

their markets are

differentiated.
Section 6 — Market Barriers and the Role of NIST

6-7

language would be available in the near future. This represents a

potential new research area for NIST.

6.2 BARRIERS TO THE ADOPTION OF

SIMULATION MODELING

Simulation modeling of IGBT devices has made its greatest

penetration in the design of automobile ignition systems, electric

vehicles, motor controls, power conditioning equipment,

electrotechnologies, and lighting. However, many industries, such

as the aircraft industry, that include IGBTs in their system design,

have not adopted simulation modeling in their design process. In

addition, the manufacturers that currently use products, such as

SABER or PSPICE, typically use mathematical modeling for only

selected design activities.

Almost all industry experts interviewed acknowledged the

“potential” benefits associated with simulation modeling of IGBTs

in the design process; however, they also indicated that certain

factors are limiting widespread adoption of IGBT simulation

modeling. The most commonly mentioned barriers to the adoption

of IGBT simulation modeling were

Z assimilation and overhead costs,

Z effort and expense required to characterize IGBT models,

Z modeling limitations and costs associated with confidential

information,

Z weak models for non-IGBT components, and

Z missing complementary analysis capabilities in simulation

software.

These barriers are discussed below.

6.2.1 Assimilation and Overhead Costs

The most commonly mentioned factor limiting penetration of IGBT

simulation modeling (and simulation modeling in general) was the

cost and complexity of learning and supporting existing simulation

software. Most of the comments were related to SABER.

Assimilation and overhead costs associated with purchasing and

supporting SABER are quantified in Section 5. These costs include

initial software purchase price, maintenance fees, component

library fees, formal staff training, and in-house SABER support staff.

Many industries,

such as the aircraft

industry, that

include IGBTs in

their system design,

have not adopted

simulation modeling

in their design

process.
Benefit Analysis of IGBT Power Device Simulation Modeling

6-8

The largest component of overhead costs is typically maintaining

in-house SABER support.

One modeling engineer said that a 6-month learning curve was

needed to effectively use of SABER’s capabilities. This type of

investment can be risky if staff turnover is high. In addition,

applications manufacturers stated that SABER support staff and

ongoing training were needed because as IGBT devices evolve,

parameter extraction techniques and modeling practices continue

to change. Thus, the assimilation of simulation modeling

capabilities is an ongoing activity.

Some motor control applications manufacturers indicated that they

limit the level of in-house expertise required by using consultants to

develop the IGBT models or by relying on component libraries.

However, many of the design benefits come from being able to

“tweak” the IGBT models when they are incorporated into the

system simulation. Thus, there is a tradeoff between the benefits

gained through simulation modeling and the level and cost of inhouse expertise needed. This decision is influenced by the volume

of IGBT design activities and the extent to which SABER is used for

other modeling activities.

6.2.2 Effort and Expense Required to Characterize IGBT

Models

Several modeling engineers indicated that IGBT simulation

modeling is useful, but difficulties in characterizing the models are

limiting the use of simulation modeling. Characterizing (also

referred to as parameterizing) simulation models adds an additional

step early in the design process, and several modeling engineers

said that upper management was often reluctant to add any new

steps to the design process, given the importance of quickly

introducing new products.

Applications manufacturers indicated that they need more

information from device manufacturers to characterize models.

Currently, device manufacturers do not provide applications

manufacturers all of the structural information and performance

parameters required to characterize the models because of

confidentiality issues. Applications manufacturers frequently take a

One modeling

engineer said that a

6-month learning

curve was needed to

effectively use

SABER’s

capabilities.
Section 6 — Market Barriers and the Role of NIST

6-9

device to the lab and make the measurements themselves to obtain

the needed information to develop the IGBT model.

The step adds time and cost to IGBT simulation modeling, thus

limiting its use by applications manufacturers. In addition, it is not

socially efficient for multiple applications manufacturers to be

replicating this measurement activity.

6.2.3 Modeling Limitations Associated with Confidential

Information

Efforts by device manufacturers to protect confidential information

not only increase applications manufacturers’ time and costs

associated with characterizing IGBT models, but also affect the

productivity of the simulation process. Applications manufacturers

said that because of gaps in data they need for characterization,

they were sometimes constrained in their ability to use simulation

for custom applications or investigate new system configurations

that might lead to enhanced system performance.

The software company Analogy provides a component library that

includes many of the off-the-shelf IGBT models that have been

provided by device manufacturers, but these models are encrypted.

As a result there are limits to the type of “what-if” scenarios that

can be performed by application manufacturers during the system

design. In PSPICE, models are not encrypted, but they are less

detailed and not as accurate. If applications manufacturers were

able to access the underlying code, this would increase the

penetration of IGBT simulation modeling into additional

applications.

Advances in the patent systems may help applications

manufacturers access proprietary software code and device

characteristics while still allowing device manufacturers to

appropriate returns for R&D investments. This would stimulate

R&D activity for device manufacturers and increase design

efficiency of applications manufacturers.
Benefit Analysis of IGBT Power Device Simulation Modeling

6-10

6.2.4 Weak Models for Non-IGBT Components

The overall accuracy of simulation modeling was also identified as

a factor limiting the adoption of IGBT simulation modeling.

Accuracy issues, however, are not related to the core IGBT model;

NIST’s model accurately predicts IGBT behavior. The issue is that

IGBTs are only one of many components in their systems that need

to be modeled to conduct simulation. FETs and transistors, for

example, also need to be modeled accurately. Simulation is only

as strong as the weakest link: if not all components can be

accurately represented because of data gaps, the ability of the

simulation to investigate design alternatives is limited.

Diodes are the most commonly mentioned “weak link” in the

simulation modeling chain. Diodes are simpler than IGBTs, and

their basic structure has not changed in several decades. Because

they were introduced prior to the use of simulation modeling, there

was no need for accurate models at the time of their design. Other

components needing improved modeling accuracy that were

identified during the interviews are transistors and resistors.

The barriers to filling in the data gaps for poorly modeled

(non-IGBT) components are the same as those discussed in

Section 6.1. Software companies do not have the technical

expertise to develop the theoretical models, and applications

manufacturers are not able to appropriate the return from R&D

investment and model verification.

6.2.5 Missing Analysis Capabilities in Simulation Software

In addition to upgrading specific non-IGBT components, modeling

engineers indicated that adding several important capabilities to

existing simulation software would increase the usefulness of IGBT

modeling and, hence, increase the impact of NIST’s model.

Additional capabilities identified during the interviews are the

following:

Z Current simulation software has difficulty modeling IGBT

devices in a predictive manner. Underlying models do not

have the capability to incorporate how variations (and

uncertainties) in IGBT parameters affect the behavioral

distribution of the system. Currently, multiple testing of

physical prototypes and “over-engineering” of design

parameters are used in the absence of these modeling

capabilities.

Simulation is only as

strong as the

weakest link: if not

all components can

be accurately

represented because

of data gaps, the

ability of the

simulation to

investigate design

alternatives is

limited.
Section 6 — Market Barriers and the Role of NIST

6-11

Z Applications manufacturers need the ability to address

variability in parts. There is always some variability in

manufactured parts (e.g., resistors, capacitors). Industry

would like to be able to incorporate Monte Carlo

simulations into the system design process to address

reliability and performance over a distribution of product

specifications. Currently there is no good approach for this.

Z Applications manufacturers indicated that they need

simulation software that includes the capability to conduct

dynamic thermal modeling. The core issue is that too much

voltage burns out IGBT devices; simulating thermal

behavior could increase product reliability. NIST’s models

have the potential to support dynamic thermal modeling;

however, these capabilities have not been incorporated into

SABER at this time. Ford and Motorola were going to begin

development of this modeling capability through a joint

venture, but the project did not proceed. NIST has expertise

in this area and is currently pursuing the development of

these capabilities.

Z For high-voltage applications, component libraries often do

not have the appropriate models so custom models must be

developed. This increases the cost of using simulation

modeling.

As before, the barriers to integrating these capabilities into

simulation software typically stem from a combination of

Z proprietary information issues,

Z the fact that the required technology base is outside

software companies’ expertise, and

Z applications manufacturers are not able to appropriate all

the returns to the required R&D investments.

6.3 FUTURE ADOPTION TRENDS AND ISSUES

Most of the applications manufacturers we interviewed plan to

increase their use of IGBT simulation modeling in the near future.

Future adoption of simulation modeling of IGBTs in the system

design process will be driven by several factors, including

Z the increased complexity of electrical systems,

Z the decreased life expectancy of new products,

Z the spread of IGBTs into additional applications,

Z software interoperability, and

Z labor mobility.

The increasing complexity of electrical systems will increase the

use of simulation modeling (including non-IGBT applications).
Benefit Analysis of IGBT Power Device Simulation Modeling

6-12

Simulation modeling of electrical systems requires the integration of

multiple separate components. It is becoming increasing costly to

use physical simulation laboratories to evaluate how IGBTs interact

with the overall system under a range of operating scenarios.

Virtual simulation for product testing will be an important pull

factor in using IGBT simulation modeling.

The decreased life expectancy of new products will increase the

adoption of simulation modeling. Industry experts indicated that

currently the decreased IGBT system design time (also referred to as

R&D cycle time) has not translated into a decrease in the overall

product development cycle time. However, as product

development cycle time becomes an increasingly large part of the

product life cycle, manufacturers will look to exploit the design

time reduction offered by simulation modeling.

New applications will also be a primary driver for the increased use

of IGBT simulation modeling. The adoption of IGBT simulation

modeling in the system design process will parallel the penetration

of IGBT devices into some markets currently dominated by

MOSFETs. MOSFETs are currently cheaper than IGBTs, but they

have larger voltage losses. Thus, MOSFETs currently dominate

lower voltage applications where the product material costs are

more important than energy usage (e.g., household appliances less

than 10 kW). However, the price of IGBTs (relative to MOSFETs) is

steadily decreasing, and IGBTs are projected to penetrate some of

the lower voltage applications’ market.

Advances in IGBT modeling software capabilities will likely be

driven by the next big “killer” IGBT application. Simulation

modeling capabilities commercially available in software packages

today have been largely driven by the automobile industry to

support the design of ignition systems and motor control

applications for the design of ASDs. The growth in the use of

IGBTs in consumer electronics and industrial equipment will

influence the use of simulation software in the future.

IGBTs will be incorporated in consumer electronics ranging from

toasters to refrigerators. In most instances component libraries will

provide off-the-shelf IGBT models that will be cost effectively

integrated into the simulation of the electrical system.
Section 6 — Market Barriers and the Role of NIST

6-13

A wide variety of industrial equipment is incorporating IGBTs for

power correction and this will increase the demand for IGBT

simulation modeling. The trend for industrial electrical equipment

is for individual units to build in their own power correction

components, as opposed to having a single bank of capacitors

sitting outside the plant where the plant interconnects with the grid.

This practice is very common already in Europe where it is

regulated as part of safety guidelines.

The interoperability of simulation software packages with different

levels of modeling complexity will lower overhead costs associated

with simulation modeling. Harris Semiconductors is currently

developing a new set of “more accurate tools” that will support

applications manufacturers that do not have SABER. Harris is

developing models of IGBTs in SABER and using them to generate

IGBT models that can then be plugged into PSPICE or other

simulation tools such as MathCad. After being developed, many of

these models are placed on the Internet and become publicly

available. As a result, non-SABER users will have a high-quality

(but not as good as SABER), low-cost system simulation tool. These

tools will be targeted to smaller companies with only a few

engineers that cannot support the overhead costs associated with

SABER.

Labor mobility will play a large role in spreading the use of IGBT

simulation modeling. As a core of modeling experience and

expertise grows, their knowledge will diffuse throughout the

industry as modeling engineers move from company to company

and take their knowledge capital with them.

6.4 FUTURE ROLES FOR NIST

The NIST program has contributed to lowering market barriers

associated with the development and adoption of IGBT simulation

modeling. Our interviews with industry experts indicate that the

private sector did not have the market incentives to fully pursue the

development of these IGBT modeling capabilities on their own. In

the absence of NIST’s contributions the development of IGBT

simulation modeling would likely have been delayed and the

models eventually implemented would not have been as accurate.
Benefit Analysis of IGBT Power Device Simulation Modeling

6-14

However, industry experts indicated that there are additional areas

where NIST’s involvement could significantly increase current

benefits associated with using IGBT simulation modeling. In

particular, supporting enhancements to simulation software and

increasing data availability could significantly increase the benefits

estimated in Section 5.

NIST is currently engaging in activities to address several of these

issues. The economic impacts of these ongoing NIST activities are

not included in the benefits and costs estimated in Section 5.

NIST is currently working with Analogy on developing an

extraction tool/procedure so that modeling engineers can extract

needed parameters for simulation without the device manufacturer

having to reveal specific structural information about the device.

This is sometimes referred to as model compartmentalization. By

protecting the device manufacturer’s intellectual property, the

extraction tool would alleviate one of the most important barriers to

widespread use of IGBT simulation modeling. However, a

limitation of the extraction procedure currently being developed is

that it is very complex. As a result, it is likely that only a handful of

large companies will be able to support the overhead training costs

needed to use the procedure. The primary users will probably be

the major device manufacturers and one or two major applications

manufacturers (Hefner, 1998).

Future activities NIST may want to consider to promote the

adoption of IGBT simulation modeling and enhance its benefits are

Z identifying and addressing weak links in the simulation

modeling chain, such as supporting model development for

other classes of devices;

Z supporting a standardized modeling language to promote

interoperability;

Z supporting analysis needed to address the impact of

variability in part on system performance and reliability;

and

Z enhancing systems for patenting device characteristics.

NIST’s current work in

model compartmentalization may alleviate one

of the most important

barriers to the widespread

use of IGBT simulation

modeling.
R-1

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References

R-3

Jednacz, Thomas C. 1991a. Conference Record of the 1991 IEEE

Industry Applications Society Annual Meeting. Dearborn,

MI 9/28-10/4/91. New York: IEEE.

Jednacz, Thomas C. 1991b. “Power Quality Design Implications

of High Frequency Lighting Ballasts and Controls.” IEEE

May:1833-1835.

Kirksey, Sandy, Visteon Electronics. Personal communication with

Michael Gallaher, Research Triangle Institute. August 1998.

Lauritzen, Peter, University of Washington. Personal

communication with Michael Gallaher, Research Triangle

Institute. August 1998.

Liu, Guangyu, Ford Motor Company. Personal communication

with Michael Gallaher, Research Triangle Institute. August

1998.

Mamileti, Lakshmikant, Stephen P. Robb, Z. John Shen, and Aileen

A. Taomoto, 1996. “IGBTs Designed for Automotive

Ignition Systems.” 27th Annual Power Electronics

Specialization Conference. 0-7803-3500-7/96.

pp. 1907-1912.

Mitchell, Carl, Energy Efficient Lighting Association. Personal

communication with Alan O’Connor, Research Triangle

Institute, September 11, 1998.

Motorola Incorporated. March 31, 1997. 10-K/A for year ended

December 31, 1996. EDGAR Database:

<http://www.sec.gov/Archives/edgar/data/68505/00009501

31-97-003500.txt>. Bethesda, MD: Lexis/Nexis.

Nelson, Richard R. 1959. “The Simple Economics of Basis

Scientific Research.” Journal of Political Economy

67:297-306.

Nielsen, B. 1993. “Load-Shape Data for Residential Lighting:

Survey Results for Incandescent and Compact Fluorescent

Lamps.” Energy 18(2):211-17.

Office of Management and Budget (OMB). 1995. “Guidelines and

Discount Rates for Benefit-Cost Analysis of Federal

Programs.” Memorandum for Heads of Executive

Departments and Establishments. OMB Circular No. A-94,

Revised.
Benefit Analysis of IGBT Power Device Simulation Modeling

R-4

OrCAD Corporation. 1998. “OrCAD and Microsim Complete

Merger.”

<http://www.orcad.com/company/pr/pr_merger.htm>.

Perry, Glenn, Analogy, Inc. 1998. Personal communication with

Michael Gallaher, Research Triangle Institute. August 1998.

Profound. 1996. Selected excerpts from report entitled “World

Manufacturers for Industrial Motors and Generators.”

<http://www.profound.com>.

Profound. 1997. “North American Power Semiconductor

Markets—Introduction, Total Market, Power Transistor, and

Rectifier Market.” <http://www.profound.com/htbin/>.

Shen, Eve, MicroSim Corporation. Personal communication with

Molly Dix, Research Triangle Institute. November 10,

1997.

Skibinski, G., W. Maslowski, and J. Pankau. 1997. “Installation

Considerations for IGBTS AC Drives.” 1997 IEE Annual

Textile, Fiber and Film Industry Technical Conference.

Greenville, SC, May 6-8.

Tassey, Gregory. 1997. The Economics of R&D Policy. London:

Quorum Books.

Theron, P.C., J.A. Ferreira, J.C Fetter, and H.W.E. Koertzen. 1993.

IEEE, 4th AFRICON Conference in Africa. Vol. 1

pp. 1319-1324.

U.S. Department of Transportation, Federal Highway

Administration. 1998. 1996 Highway Statistics.

Washington, DC: Government Printing Office.

U.S. Department of Energy. 1997. “Electric Power Annual 1997

Volume 1.”

<http://www.eia.doe.gov/cneaf/elctricity/epav1/

epav1_sum.html>.
Appendix A:

Background

Information on IGBTs
A-1

A.1 HISTORY OF SEMICONDUCTOR POWER

DEVICES

In 1948, American physicists John Bardeen, Walter H. Brattain, and

William Shockley of Bell Telephone Laboratories invented the

transistor, a device at the heart of modern power electronics. The

transistor is a small electronic unit consisting of semiconductor

materials (impure germanium and silicon) used as a voltage and

current amplifier in electrical machinery and equipment. Nearly

50 years after its invention, the bipolar transistor has developed to

such an extent that millions of transistors can occupy a fingernailsized sliver of silicon (Baliga, 1997).

A transistor is designed to operate switches and block or permit the

flow of electric current. Transistors are distinguished by the

amount of power they control, which is determined, in turn, by the

individual unit’s maximum operating voltage and current-handling

capability. When the transistor is switched on, either with voltage

or current depending on the type, electric current is allowed to pass

through the device. When the transistor is switched off, electric

current is blocked from coursing through the transistor. At the

same time, the transistor maintains its support of the voltage on the

wire.

Soon after its discovery at Bell Labs, the transistor technology was

applied to all forms of electric devices. Two trends quickly

developed: one towards miniaturization, the other towards the

grandiose (Baliga, 1997). For products ranging from radios to the

earliest computers, the transistor was shrunk to fit in all manners of

microapplications, ushering in the age of electronics. For other

applications, the transistor was enlarged and built to withstand and

conduct massive amounts of power on command for generators

and in power conditioners.

The complementary metal oxide semiconductor (CMOS) was an

improvement on the bipolar transistor and was developed in the

early 1970s. The introduction of the CMOS allowed greater power

gain and control, but it was subject to destructive failures,

necessitating the use of protective circuits. CMOSs were originally

developed for microelectronic applications but have since become

the basic building block of silicon integrated circuits.
Benefit Analysis of IGBT Power Device Simulation Modeling

A-2

A descendant of the CMOS, the metal oxide semiconductor field

effect transistor (MOSFET) switches on and off faster and does not

require the cumbersome protection circuits that bipolar transistors

need. It switches on and off with voltage, not current. Current flow

is limited to short bursts whenever the MOSFET is turned off or on.

Although the MOSFET’s ability to manage low voltages is well

documented, its current-handling capability is less effective when

operated at more than 100 volts. MOSFETs are found in consumer

electronics, personal computers, automotive systems, and other

low-power applications; it is currently known as the every-day

transistor.

In the late 1970s, experiments with MOSFET/bipolar transistor

combinations led to MOSFETs that could be used to control a

bipolar transistor. These devices can be switched by a small

voltage, while still operating at high amperes. This discovery,

known as a MOS-gated thyristor, led to RCA’s 1982 discovery of

the IGBT. IGBT semiconductors are about the size of a postage

stamp and can be grouped together to switch up to 1,000 amperes

of electric current at voltages of up to several thousand volts.

Currently power electronics devices control an estimated 50 to 60

percent of the electric power generated in developed countries

(Baliga, 1997). They are used in products as varied as car ignitions,

electric bullet trains, blenders, fluorescent light ballasts, and

computers. Table A-1 presents the power transistor market by

product.

Product Revenues (%)

Bipolar 60

MOSFET 30

IGBT 10

Source: Profound. 1997. “North American Power Semiconductor Markets—

Introduction, Total Market, Power Transistor, and Rectifier Market.”

<http://www.profound.com/htbin/>.

A.2 TECHNICAL CHARACTERISTICS OF IGBTS

The IGBT is a hybrid of two transistors: the bipolar transistor and

the MOSFET. The simple bipolar transistor consists of three layers:

Table A-1. North

American Power

Transistor Market: 1993
Appendix A — Background Information on IGBTs

A-3

the top (the emitter), the middle (the base), and the bottom (the

collector). The three layers alternate conductivity type. The areas

between the conductivity types are called p-n junctions. Electrons

pass through these junctions to move from one layer to another. If

the electric potential or voltage on the segments is properly

determined, a small current between the emitter and base

connections generates a large current between the emitter and

collector connections, thereby producing current and amplification

(Columbia Encyclopedia, 1998).

Base bipolar transistors and MOSFETs are the two types of

transistors used in IGBTs. Bipolar transistors are simple in design

and rugged in performance. They effectively control large amounts

of power and can be switched at high speeds. The main drawback,

however, is that the amount of power they consume is directly

related to the amount of power they control and conduct. In other

words, bipolar transistors require a large current flow to control a

larger current (Baliga, 1997).

The base bipolar transistor used in IGBTs is the p-n-p transistor.

This transistor is the inverse of the standard n-p-n bipolar. The

standard bipolar has a narrow base region and a lightly doped,

thick collector. In contrast, the IGBT’s base is thick and lightly

doped and the collector is thin and highly doped. The advantage of

the transistor’s inverse properties is that they enable it to support

high voltages across its output terminals, emitter, and collector

when it is turned off. This had been previously accomplished by

making the collector thick and lightly doped, but in an IGBT this is

accomplished using thinner layers (Baliga, 1997).

MOSFETs are the other type of transistor used in IGBTs. MOSFETs

evolved from the CMOS that had been developed during the 1970s

for microelectronics. The n-p-n MOSFET, or n-channel MOSFET,

has two n-type regions, the source and drain, that play the same

roles as the collector and emitter in the bipolar transistor. The base

in the MOSFET is known as the substrate, the p-type region. The

top of the substrate is a metal gate that allows an electrical field to

be created in the substrate when a positive voltage is applied to it.

The field forces positively charged holes (electron deficiencies)

from the substrate through the gate while attracting electrons

toward the substrate surface. The moving electrons allow the

current to flow through the substrate. From the perspective of an
Benefit Analysis of IGBT Power Device Simulation Modeling

A-4

IGBT, the key attribute of the MOSFET is that it is switched on and

off with voltage, not current.

MOSFETs cannot control large amounts of power, but they can be

switched on and off at incredibly high speeds. In addition, they do

not require the protective circuits of their predecessor, the CMOS.

The main limitation of MOSFETs is in their ability to efficiently

handle high-voltage currents. As a MOSFET controls voltages of

100 volts or more, it loses its ability to control that power

efficiently.

The inefficiency of MOSFETs at high power led to the development

of the IGBT for controlling medium-power devices in the 1980s. In

an IGBT, the MOSFET provides the control current to the bipolar

transistor. To create an IGBT, the bipolar transistor and the

MOSFET are joined so that the channel current flowing in the

substrate of the MOSFET is also the current that is applied to the

base of the bipolar transistor. The technical advantages from

joining these two devices are threefold (Baliga, 1997). First, the

IGBT’s MOSFET is typically controlled by 10 volts, but the whole

unit can control nearly 1,500 volts and 100 amperes. This equates

to a possible power gain of 10 million or more. The high power

gain allows the unit to be controlled by delicate integrated circuits

but requires the use of protective circuits to prevent destructive

failure.

Second, the IGBT has a higher operating current density than its

components. The electrical current flowing through the IGBT’s

MOSFET is the control current for the bipolar transistor. The

bipolar transistor’s emitter-collector current joins the MOSFET’s

channel current to produce the IGBT’s total output current. The

two currents from the IGBT’s components are equal; therefore, the

IGBT’s output current is double that of either of its components.

Third, when switched on, the IGBT has very low electrical

resistance between the collector and the emitter. Because so many

electrons and holes flow through the bipolar’s base region from the

emitter and collector, the base’s conductivity increases 1,000 times.

The improved conductivity keeps power loss at a minimum,

especially when compared to the MOSFET and bipolar transistor

alone. These three attributes allow IGBTs to be smaller, more

efficient, and less expensive to produce for the manufacturer.
Appendix B:

Acceleration Effect
B-1

Mathematical modeling of IGBT devices can accelerate product

availability, improve the value of products, and reduce the cost of

designing and manufacturing products containing IGBT devices.

The acceleration of new product introduction creates an important

temporal element for the impact analysis. Over time, the relevant

baseline for estimating the effects of mathematical modeling

changes. Thus, we need three scenarios to model the economic

impact of mathematical modeling: two baseline scenarios and one

mathematical modeling (or MM) scenario. We define the scenarios

as follows:

➤ Baseline 1: product does not contain an IGBT device

➤ Baseline 2: product contains an IGBT device but is not

designed with mathematical modeling

➤ MM scenario: product contains an IGBT device and is

designed with mathematical modeling

Over the lifetime of a product, the relevant baseline for measuring

the impact of mathematical modeling will change. Figure B-1

illustrates how the baseline changes over time and how this affects

our measurement of the net social surplus associated with

mathematical modeling. Suppose that S1 represents the net social

surplus of a product without an IGBT device (Baseline 1). S2

represents the social value of a product with an IGBT device that is

not designed and produced using mathematical modeling

(Baseline 2). S3 represents the social value of a device with an

IGBT that was produced with mathematical modeling. t1

represents the time at which the product with the IGBT device is

introduced if mathematical modeling is used; t2 is the time at which

this product would be introduced in the absence of mathematical

modeling; and t3 represents the end of the product’s life cycle.

The net impact of mathematical modeling is equal to areas E+F+G.

In the absence of mathematical modeling, the social surplus

associated with the product over its entire life cycle is equal to

areas A+B+C+D. Until t2, the product does not contain an IGBT,

and its social surplus is equal to S1. At t2, the product’s value

increases to S2. However, if mathematical modeling is used to

design and produce the product, the IGBT is introduced sooner, at

t1 rather than t2. Furthermore, rather than S2, the product’s value is

S3; mathematical modeling has increased its performance relative
Benefit Analysis of IGBT Power Device Simulation Modeling

B-2

Figure B-1. The Timeline of Benefits from Mathematical Modeling of IGBT Devices

The baseline needed to construct the counterfactual scenario changes over time.

Time

S3

0

Baseline 1

Baseline 2

MM Scenario

t

2

Annual Social

Surplus

E

A B

S2

S1

t

1 t3

D

C

F G

0 = date of introduction of previous generation of product

t1 = date at which IGBT is introduced in the MM scenario

t2 = date at which IGBT is introduced in the without-MM scenario

t3 = end of product lifespan

Benefits without MM = A+B+C+D

Benefits with MM = A+B+C+D+E+F+G

Net benefit = E+F+G

E+F = acceleration impact

G = product/process improvement impact

to a product with an IGBT that is not designed with mathematical

modeling. Thus, the product’s social surplus in the mathematical

modeling scenario is equal to areas A+B+C+D+E+F+G. We call

areas E + F the acceleration impact; area G is the product/process

improvement impact.
Appendix C:

Survey Instrument:

Applications

Manufacturers
1

Questionnaire

Applications Manufacturers

Introduction

On behalf of the National Institute of Standards and Technology (NIST), Research Triangle Institute

(RTI) is conducting an evaluation of NIST’s contributions to the development of simulation

modeling techniques used for the simulation of semiconductor power devices. As part of this

evaluation, we are investigating the benefits and costs of using simulation software in the system

design of products employing insulated-gate bipolar transistors (IGBTs).

In general, we are interested in measuring the value of having simulation models for IGBTs

available for use in system design. Specific issues of interest to NIST are

• the cost and time savings associated with using simulation software such as SABER and

PSPICE;

• the limitations of simulation modeling of IGBT designs;

• enhancements that accelerated the adoption of simulation modeling techniques;

• the impact of simulation modeling on companies’ decisions to incorporate IGBTs into their

new products or redesigned existing products;

• improvements in the efficiency of end products employing IGBTs resulting from simulation

modeling techniques; and

• impacts on production, such as material costs, yield, or time to market improvements

resulting from using simulation techniques.

Our study would benefit a great deal from your input. Please read and consider the enclosed

questions as they relate to your company’s products. We encourage you to collaborate with your

colleagues when answering these questions, because several questions span a variety of aspects of

the product design and development process.

Any information you provide will remain strictly confidential. Only national-level cost and benefits

impacts will be published in our study. Product- and company-level information will be used to

estimate national-level impacts, but will not be included in any intermediate or final reports.

A staff member from RTI will contact you in the next few days to answer any questions you may

have. At that time you may respond to these questions over the phone or make an appointment to

do so at a later date. Alternatively you may complete the questionnaire and e-mail or fax it to us at

mpg@rti.org or (919) 541-6683. At any time, if you have any questions, please feel free to contact

Mike Gallaher at (919) 541-5935 or Alan O’Connor at (919) 541-7186. Thank you for your input to

our study.

1. Company Identification

Company Name:

Mailing Address:

Contact Name:

Title:

Phone Number:
2

2. Product Information

2.1 In the table below, please identify the product lines your company manufactures that

incorporate IGBT power devices. For each product line, provide the unit size ranges

manufactured and the number of different circuit architecture designs. In particular, we

are interested in the number of circuit architectures used in the product line employing

different IGBT system designs. In addition, provide the approximate number of units

sold in the previous fiscal year and indicate the year IGBTs were first incorporated into

this product line.

Table 1. Product Lines Incorporating IGBTs

Product Line Description

Size

Range

Number of Different

Circuit Architecture

(IGBT System) Designs

Number of

Units Sold

Per Year

Year IGBTs

First Used

Example:

Ignition switches for trucks

All one for small trucks

one for large trucks

100,000 1992
3

2.2 For the product lines listed in Table 1, please indicate the benefits and costs associated

with incorporating IGBTs into the product, relative to the alternative device (MOSFET

or other controllable switching system).

Table 2. Benefits and Costs of Using IGBTs

Product Line

Alternative

Device

Percent

Increase in

Efficiencya

Percent

Reduction in

Manufacturing

Costsb

Percent Decrease

(Increase) in

Design Costs

Example:

Ignition switch for trucks

MOSFET No impact on

fuel efficiency

0.5% of total cost

of truck

20% decrease

aPlease provide a percentage change in efficiency of final product. If efficiency change is for a subcomponent please

describe the subcomponent.

bPlease provide per-unit percentage change in manufacturing costs for the final product.
4

2.3 Please describe other benefits or costs (not listed in Table 2) associated with

incorporating IGBTs, such as changes in product reliability, maintenance costs, etc.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________
5

3. General Information on IGBT Power-Device System Design

3.1 Approximately how many times per year does your company conduct a system design

process that incorporates IGBT power devices?

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

3.2 When new or updated products are developed, does this generally require a revision of

the electronics system containing IGBT power devices? Please explain.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

3.3 Is a separate system design process required for each product? Please explain.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________
6

3.4 Do you use simulation modeling as part of your system design process for products

incorporating IGBTs?

Yes Continue to Question 3.5

No

If no, answer the following questions in the space below and skip the remainder of

the questions in this survey. Thank you for your input.

a. Please explain why simulation modeling is not used.

b. What are its shortcomings relative to the design of your products?

c. Do you plan to use simulation modeling in the future?

d. What are you using in place of simulation modeling to verify the design

(e.g., prototypes in hardware)?

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________
7

3.5 Figure 1 contains a flow chart of the design process for systems incorporating IGBT

power devices. Does the process flow in this figure accurately represent the typical

system design process with and without simulation modeling? Please elaborate.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

Figure 1. Design Process

Product Conception

Initial Product Design

IGBT Testing in Breadboard

Product Prototype

IGBT System Production

Final Product Production

NIST

If Simulation Modeling Is Used

Mathematical

Modeling

IGBT

Specs

Performance

Parameters

Iteration Without Simulation Modeling

Pass

Modify Specifications

Fail

IGBT Design or Selection

System Design

Virtual Testing in Product

Masking: Physical

Prototype Development
8

3.6 Using the list of products you provided in Table 1 indicate whether simulation modeling

is used in the design process and when your company began using simulation modeling.

Also indicate the frequency of product design processes per year and the specific

software used (e.g., SABER, PSPICE).

Table 3. Use of Simulation Modeling

Product Line

Simulation Modeling Used in

Design Process

(Y/N)

Year

First Used Software Used
9

3.7 In Table 4, provide the overhead costs associated with each simulation software product

that you use.

Table 4. Overhead Costs

Software Number of Licenses Cost per License

Labor Hours for Training

(per year) to Support

Software

SABER

PSPICE

others

3.8 What is the average hourly wage of design engineers employing the software programs

listed in Table 4? _______ per hour.

What is their fringe benefit rate? _______ %
10

4. Impact of Simulation Modeling on the System Design Process

Our preliminary interviews have suggested that simulation modeling provides an understanding of

the IGBT system design without physically procuring materials and building a prototype. Thus,

simulation modeling reduces the number of design iterations, saving time and design labor hours.

Please answer the questions below to help us determine the extent of resource savings from

simulation modeling.

An example framework for providing this information is provided below. However, if this is not

applicable, please use any framework that may be appropriate.

Example:

Simulation modeling provides an understanding of the IGBT system design without

physically procuring materials and building a prototype. Each time an IGBT design is

modified (referred to as an iteration, see Figure 1), an estimated $$ is spent for new mask

sets, and there can be a delay of X weeks. Historically, IGBT design required Y

iterations. With simulation modeling, a design may require only Z iterations.

4.1 Describe in general how using these simulation software products influences your design

activities. Describe the alternative design process without simulation modeling of

IGBTs.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

4.2 Considering the products listed in Table 1, how many iterations, on the average, were

required to complete an IGBT design before you started using simulation modeling?

_______ iterations

4.3 How many are required now, with the use of simulation modeling? _______ iterations

4.4 On the average, what is the cost of developing new mask sets and other materials

required for each iteration? $_______/iteration

4.5 How many hours of labor are required per design iteration? $_______/iteration
11

4.6 Has simulation modeling accelerated the design process?

Yes

No

If yes, by how many weeks or months? _______ weeks/months

4.7 Has this accelerated the introduction of new products?

Yes

No

If yes, by how many weeks or months? _______ weeks/months

5. Impact of Simulation Modeling on the Manufacturing Process

Some system designers have indicated that using simulation modeling reduces the cost of

production for products with IGBT devices because it improves the predictability of the products’

performance. Please answer the following questions in general with respect to the products your

company produces that employ IGBT devices:

5.1 Does simulation modeling reduce the cost of materials required to produce these

products?

Yes

No

If yes, what would you estimate to be the percentage change in materials costs for these

products from the use of simulation modeling? _______%

What percentage of TOTAL production costs is attributable to materials costs?

_______%

5.2 Does simulation modeling affect the manufacturing defect rate? 

Yes

No

If yes, please indicate, on average, the defect rate with and without simulation modeling.

Without simulation modeling: _______ per thousand

With simulation modeling: _______ per thousand
12

5.3 Does simulation modeling affect the product testing rate?

Yes

No

If yes, please indicate, on average, the testing rate with and without simulation modeling

and the appropriate cost per test:

Without simulation modeling: _______ per thousand

With simulation modeling: _______ per thousand

Cost per test: $_______

6. Impact of Simulation Modeling on Final Product Performance

We know that using IGBTs has important effects on the performance of many products. Some

system designers have indicated that using simulation modeling in designing IGBT systems

improves predictive accuracy and expands the performance range of the IGBT component system,

resulting in increased quality of final products employing IGBTs.

6.1 Does the use of simulation modeling further improve the product over and above the

product improvements described in Section 2?

Yes

No

If yes, please explain.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________
13

6.2 Please use Tables 5 and 6 to provide specific information on increased final product

quality for each product line. Please separate the impact of including an IGBT in the

product design from the impact of using simulation modeling in the design process.

Table 5. Increased Final Product Quality from IGBTs’ Simulation Modeling

Brief Technical Description of Impact on

Product Quality/Reliability/Weight, etc.

Product Line

(Keep same order as in Table 1) Impact of IGBTs Impact of Simulation Modeling
14

Table 6. Impact of IGBTs and Simulation Modeling on Energy Consumption and Maintenance

Requirements

Impact on Energy Consumption

(For Example, Percentage Change

in Efficiency)a

Impact on Maintenance Requirements

(For Example, Percentage Change

in Costs)

Product Line

(keep same order

as in Table 1) Impact of IGBTs

Impact of

Simulation

Modeling Impact of IGBTs

Impact of

Simulation

Modeling

aFor example, if a unit had an energy efficiency rating (EER) of 92 percent before IGBTs were incorporated and an EER

of 95 percent after IGBTs were incorporated, the increase in efficiency would be 3 percentage points. Or, if a line of

air conditioning units went from 10.5 SEER to 12.5 SEER, this represents a 12.5 – 10.5

10.5 = 19 percent increase in

efficiency. If efficiency change is for a subcomponent please describe the subcomponent and its share of energy usage

in the final product.
15

6.3 Are other benefits gained from using simulation techniques?

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

Thank you for your assistance.
Appendix D:

Survey Instrument:

Device

Manufacturers
1

Questionnaire

Device Manufacturers

Introduction

On behalf of the National Institute of Standards and Technology (NIST), Research Triangle Institute

(RTI) is conducting an evaluation of NIST’s contributions to the development of simulation

modeling techniques used for the simulation of semiconductor power devices. As part of this

evaluation, we are investigating the benefits and costs of using simulation software in the design of

products employing insulated-gate bipolar transistors (IGBTs).

In general, we are interested in measuring the value of having simulation models for IGBTs

available for use in device and system design. Specific issues of interest to NIST are

• the cost and time savings associated with using simulation software such as SABER and

PSPICE;

• the limitations of simulation modeling of IGBT designs;

• enhancements that accelerated the adoption of simulation modeling techniques;

• the impact of simulation modeling on companies’ decisions to incorporate IGBTs into their

new products or redesigned existing products;

• improvements in the efficiency of end products employing IGBTs resulting from simulation

modeling techniques; and

• impacts on production, such as material costs, yield, or time to market improvements

resulting from using simulation techniques.

Our study would benefit a great deal from your input. Please read and consider the enclosed

questions as they relate to your company’s activities and clients. We encourage you to collaborate

with your colleagues when answering these questions, because several questions span a variety of

aspects of the product design and development process.

Any information you provide will remain strictly confidential. Only national-level cost and benefits

impacts will be published in our study. Product- and company-level information will be used to

estimate national-level impacts, but will not be included in any intermediate or final reports.

A staff member from RTI will contact you in the next few days to answer any questions you may

have. At that time you may respond to these questions over the phone or make an appointment to

do so at a later date. Alternatively you may complete the questionnaire and e-mail or fax it to us at

mpg@rti.org or (919) 541-6683. At any time, if you have any questions, please feel free to contact

Mike Gallaher at (919) 541-5935 or Alan O’Connor at (919) 541-7186. Thank you for your input to

our study.

1. Company Identification

Company Name:

Mailing Address:

Contact Name:

Title:

Phone Number:
2

2. Products Employing IGBTs

2.1 In the table below, please identify the major systems manufacturers that your company

has worked with in designing IGBT power device systems. For each systems

manufacturer, list their product lines that incorporate IGBTs. We are also interested in

the number of circuit architectures used in each product line employing different IGBT

system designs. For example, if manufacturer X produces a line of air conditioners that

incorporate IGBTs, how many different IGBT system designs are needed to support their

line of air conditioners? In addition, indicate the year IGBTs were first incorporated into

each product line.

Table 1. Product Lines Incorporating IGBTs

Major Manufacturers Products

Number of Different

Circuit Architecture

(IGBT System) Designs

Year IGBTs

First Used

Example: Manufacturer X Product A

Product B

Product C

3

1

2

1994

1992

1997
3

2.2 For the systems manufacturers and product lines listed in Table 1, please indicate the

benefits and costs associated with incorporating IGBTs into the product, relative to the

alternative device (MOSFET or other controllable switching system).

Table 2. Benefits and Costs of Using IGBTs

Manufacturer/

Product Line Alternative Device

Increase in Operating

Efficiencya

Percent Decrease

(Increase) in Design Costs

Example: Manufacturer X:

 -Product A

 -Product B

 -Product C

MOSFET

None

MOSFET

2%

1%

None

30%

30%

20%

aFor example, if a unit had an energy efficiency rating (EER) of 92 percent before IGBTs were incorporated and an EER

of 95 percent after IGBTs were incorporated, the increase in efficiency would be 3 percentage points. Or, if a line of

air conditioning units went from 10.5 SEER to 12.5 SEER, this represents a 12.5 – 10.5

10.5 = 19 percent increase in

efficiency. If efficiency change is for a subcomponent please describe the subcomponent and its share of energy usage

in the final product.
4

2.3 Please describe other benefits or costs (not listed in Table 2) associated with

incorporating IGBTs, such as changes in product reliability, maintenance costs, etc.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________
5

3. IGBT Power-Device Design

3.1 Approximately how many new or modified IGBT power devices does your company

design per year?

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

3.2 When new or updated products are developed, does this generally require the

development of a new IGBT power device? Please explain.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

3.3 Please describe your IGBT device design process.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________
6

3.4 Do you use simulation modeling as part of your IGBT device design process for products

incorporating IGBTs?

Yes Continue to Question 3.5

No

If no, answer the following questions in the space below and skip the remainder of

the questions in this survey. Thank you for your input.

a. Please explain why simulation modeling is not used.

b. What are its shortcomings?

c. Do you plan to use simulation modeling in the future?

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________
7

3.5 Using the list of systems manufacturers and product lines you provided in Table 1

indicate whether simulation modeling is used in the design process and approximately

what year simulation modeling was first used in each product line. Also indicate the

specific software used (e.g., SABER, PSPICE).

Table 3. Use of Simulation Modeling

Product Line

Simulation Modeling Used

in Design Process

(Y/N)

Year

First

Used

Software Used

Example: Manufacturer X:

 -Product A

 -Product B

 -Product C

Y

Y

N

1993

1993

NA

SABER

PSPICE

NA
8

3.6 In Table 4, provide the overhead costs associated with each simulation software product

that you use (e.g., SABER, PSPICE).

Table 4. Overhead Costs

Software Number of

Licenses

Original Purchase Cost

per License

(and year of purchase)

Additional Annual

Maintenance or

Update Costs

Labor Hours for

Training (per year) to

Support Software

Example: SABER 3 $XXX.00

(1992)

$XX.00/yr 2 staff members

50 hours each

3.8 What is the average hourly wage of design engineers employing the software programs

listed in Table 4? _______ per hour.

What is their fringe benefit rate? _______ %
9

4. Impact of Simulation Modeling on the System Design Process

Our preliminary interviews have suggested that simulation modeling provides an understanding of

the IGBT system design without physically procuring materials and building a prototype.

4.1 Figure 1 contains a flow chart of the design process for systems incorporating IGBT

power devices. Does the process flow in this figure accurately represent the typical

system design process with and without simulation modeling? Please elaborate.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

Figure 1. Design Process

Product Conception

Initial Product Design

IGBT Testing in Breadboard

Product Prototype

IGBT System Production

Final Product Production

NIST

If Simulation Modeling Is Used

Mathematical

Modeling

IGBT

Specs

Performance

Parameters

Iteration Without Simulation Modeling

Pass

Modify Specifications

Fail

IGBT Design or Selection

System Design

Virtual Testing in Product

Masking: Physical

Prototype Development
10

We are interested in how simulation modeling affects the number of design iterations, saving time

and design labor hours. Please answer the questions below to help us determine the extent of

resource savings from simulation modeling.

An example framework for providing this information is provided below. However, if this is not

applicable, please use any framework that may be appropriate.

Example:

Simulation modeling provides an understanding of the IGBT system design without

physically procuring materials and building a prototype. Each time an IGBT design is

modified (referred to as an iteration, see Figure 1), an estimated $$ is spent for new mask

sets, and there can be a delay of X weeks. Historically, IGBT design required Y

iterations. With simulation modeling, a design may require only Z iterations.

4.2 Describe in general how using these simulation software products influences your design

activities. Describe the alternative design process without simulation modeling of

IGBTs.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

4.3 Considering the products listed in Table 1, how many iterations, on average, were

required to complete an IGBT design before you started using simulation modeling?

_______ iterations

4.4 How many are required now, with the use of simulation modeling? _______ iterations

4.5 On the average, what is the cost of developing new mask sets and other materials

required for each iteration? $_______/iteration

4.6 On average, how many hours of labor are required per design iteration?

$_______/iteration
11

4.7 Has simulation modeling accelerated the design process?

Yes

No

If yes, by how many weeks or months? _______ weeks/months on average

4.8 Has this accelerated the introduction of new products?

Yes

No

If yes, by how many weeks or months? _______ weeks/months on average

5. Impact of Simulation Modeling on Final Product Performance

We know that using IGBTs has important effects on the performance of many products. Some

system designers have indicated that using simulation modeling in designing IGBT systems

improves predictive accuracy and expands the performance range of the IGBT component system,

resulting in increased quality of final products employing IGBTs.

5.1 Does the use of simulation modeling further improve the product over and above the

product improvements described in Section 2 (i.e., we are interested in the benefits from

simulation modeling of IGBTs separate from the benefits of IGBTs over alternative,

controllable switching technologies)?

Yes

No

If yes, please explain.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________
12

5.2 Please use Table 5 to provide specific information on increased final product quality for

each product line. Please separate the impact of including an IGBT in the product design

from the impact of using simulation modeling in the design process.

Table 5. Increased Final Product Quality from IGBTs’ Simulation Modeling

Brief Technical Description of Impact on

Product Quality/Reliability/Weight, etc.a

Product Line

(Keep same order as in Table 1) Impact of IGBTs Impact of Simulation Modeling

aPlease provide quantitative impact estimates if possible.
13

5.3 Are other benefits gained from using simulation techniques?

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

Thank you for your assistance.
Appendix E:

Survey Instrument:

Software Developers
1

Questionnaire

Software Developers

Introduction

On behalf of the National Institute of Standards and Technology (NIST), Research Triangle

Institute (RTI) is conducting an evaluation of NIST’s contributions to the development of

mathematical modeling techniques used for the simulation of semiconductor power devices. As

part of this evaluation, we are investigating the benefits and costs of using simulation software in

the system design of products employing insulated-gate bipolar transistors (IGBTs).

The issues of particular interest to NIST include

➤ the penetration of simulation modeling of IGBT system design in new products or the

redesign of existing products,

➤ the limitations of simulation modeling of IGBTs,

➤ enhancements that would accelerate the adoption of simulation modeling techniques, and

➤ NIST’s contribution to the development of simulation software products.

Our study would benefit a great deal from your input. Please read and consider the enclosed

questions as they relate to your company’s software products. We encourage you to collaborate

with your colleagues when answering these questions, because several questions span a variety of

aspects of the product design and development process.

Any information you provide will remain strictly confidential. Only national-level cost and

benefits impacts will be published in our study. Product- and company-level information will be

used to estimate national-level impacts, but will not be included in any intermediate or final

reports.

A staff member from RTI will contact you in the next few days to answer any questions you may

have. At that time you may respond to these questions over the phone or make an appointment to

do so at a later date. Alternatively you may complete the questionnaire and fax it to us at

919-541-6683. At any time, if you have any questions, please feel free to contact Mike Gallaher

at 919-541-5935 or Alan O’Connor at 919-541-7186. Thank you for your input to our study.

1. Company Identification

Company Name:

Mailing Address:

Contact Name:

Title:

Phone Number:
2

Section 1. Market Penetration of Simulation Modeling

1.1 Please describe your company’s software products that support simulation modeling

of IGBTs.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

1.2 Are your IGBT simulation components stand alone products or are they modules in a

large simulation package?

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

1.3 Please describe how your simulation software product is used by device

manufacturers and system designers.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________
3

1.4 In Table 1, please list the major products that employ IGBTs. For each product,

estimate the percentage of existing IGBT products that have been designed using

simulation modeling and how this percentage is likely to change over the next 5 years.

Table 1. Products Incorporating IGBTs

Product Line Description

% of Existing IGBT Products

Designed Using Simulation Modeling

% Designed Using Simulation

Modeling in 2003

Example:

Air Conditioners

70% 95%
4

1.5 In Table 2, please identify additional products for which simulation modeling of

IGBTs will likely be used in the future.

Table 2. Products Likely to Incorporate IGBTs in the Future

Product Description Time Horizon for Product Introduction
5

1.6 What are some of the limitations of existing simulation modeling techniques?

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

1.7 What model enhancements would accelerate the adoption of simulation modeling

techniques?

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________
6

Section 2. Software Development

As part of our evaluation of the benefits of simulation modeling in the design of IGBT systems,

we need to estimate the cost of developing the software tools used by device manufacturers and

system designers.

2.1 When did your company first introduce IGBT modeling capabilities into your

software products?

______________

2.2 What was your company’s investment in the development of the software components

that support the simulation of IGBT systems?

Length of time to develop (months) ____________________________________

Cost of development ($$) ____________________________________________

2.3 If the software development was a joint venture with other companies or educational

or government agencies (other than NIST), please estimate their total expenditures in

Table 3.

Table 3. Software Development Expenditures by Other Organizations

Company or Agency Name Total Expenditures
7

Section 3. NIST’s Contribution to the Development and Adoption of Simulation

Modeling of IGBT Power Devices

Over the past 8 years Dr. Allen Hefner, Project Leader, Semiconductor Electronics Division at

NIST, has contributed to the development of mathematical models that predict device

performance of IGBTs.

3.1 Please comment on the impact NIST has had in the development of your company’s

simulation modeling software for IGBT power devices.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

3.2 Without NIST’s contribution to the development of mathematical models, would your

company have developed the modeling techniques?

Yes

No

Please explain the factors that would have influenced your decision to either proceed

or not proceed with development on your own.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________
8

3.3 If you would have developed the modeling techniques yourself,

Z would you have developed them in the same time frame? When do you predict

you would have introduced a software product with comparable capabilities?

________________________________________________________________

________________________________________________________________

________________________________________________________________

Z do you think your simulation models would have been as accurate as the existing

models based on NIST’s algorithms? Please explain.

________________________________________________________________

________________________________________________________________

________________________________________________________________

3.4 Do you think that NIST’s involvement in this area has

Z accelerated the adoption of circuit simulation models and virtual prototyping by

system designers and device manufacturers? Please explain.

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

Z lowered the cost of using simulation software by reducing license fees or

increasing user friendliness? Please explain.

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

________________________________________________________________

Thank you for your assistance.
Appendix F:

Completed

Interviews
F-1

F.1 TECHNICAL INTERVIEWS

The number of persons interviewed at each organization is shown

in parentheses.

F.1.1 Software Companies

Analogy Inc. (2)

F.1.2 Device Manufacturers

Harris Semiconductor (2)

International Rectifier (1)

F.1.3 Applications Manufacturers

Rockwell Automation/Allen-Bradley (2)

Visteon Electronics Division (3)

(Fully owned subsidiary of Ford)

Ford Electric Vehicle Division (1)

General Electric Company-CRD (1)

F.2 SCOPING INTERVIEWS

F.2.1 Academics

University of Colorado (1)

University of Washington (1)

Virginia Tech (1)

University of Tennessee (1)

F.2.2 Software Companies

Analogy Inc. (1)

MicroSim Corp (1)

F.2.3 Device Manufacturers

Consultant to Harris Semiconductor (1)

International Rectifier (1)

Harris Semiconductor (1)

F.2.4 Applications Manufacturers

General Electric (1)