January 2004 • NREL/SR-520-35177 

J. Bohland, A. McMaster, S. Henson, and 

J. Hanak 

First Solar, LLC 

Perrysburg, Ohio 

Specific PVMaT R&D in CdTe 

Product Manufacturing

Final Subcontract Report 

March 2003 

National Renewable Energy Laboratory 

1617 Cole Boulevard 

Golden, Colorado 80401-3393 

NREL is a U.S. Department of Energy Laboratory 

Operated by Midwest Research Institute • Battelle 

Contract No. DE-AC36-99-GO10337 
January 2004 • NREL/SR-520-35177

Specific PVMaT R&D in CdTe 

Product Manufacturing

Final Subcontract Report 

March 2003 

J. Bohland, A. McMaster, S. Henson, and 

J. Hanak 

First Solar, LLC 

Perrysburg, Ohio 

NREL Technical Monitor: R.L. Mitchell

Prepared under Subcontract No. ZAX-8-17647-06 

National Renewable Energy Laboratory 

1617 Cole Boulevard 

Golden, Colorado 80401-3393 

NREL is a U.S. Department of Energy Laboratory 

Operated by Midwest Research Institute • Battelle 

Contract No. DE-AC36-99-GO10337 
This publication was reproduced from the best available copy 

Submitted by the subcontractor and received no editorial review at NREL

NOTICE

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iii

Acknowledgements 

 Multiple investigators have been involved in this subcontract. This document is a 

compilation of work performed by the principal investigators and the contributors listed 

below. 

John Bohland Principal Investigator Phase I 

Alan McMaster Principal Investigator Phase II and III 

Sam Henson Principal Investigator Final 

Dr Joseph Hanak Consultant 

Contributors: John Bohland, Eugene Bykov, Chris Flores, Frank Borgeson, Wayne Monie, 

Ken Smigielski, Chris Zarecki, Mike Ross, Jim Poddany, Dr. Joseph Hanak, Product Search, 

Inc, Matt Flis, Todd Dapkus, Steve Cox, Verlin Champion, Gary Faykosh, Mike McArthur, 

Tom Dunn, Larry Crosser Peter Meyers 

Knowing that we are inadvertently omitting many who have assisted in this program, we 

would still like to express our thanks for measurements, collaboration, and technical 

guidance we have received from NREL staff, and other First Solar employees as well as 

previous employees from Solar Cells Inc. 

This work has been supported in part by NREL subcontract ZAX-8-17647-06. 

Contact Information 

Technology: Applications: 

First Solar, LLC - Technology Center First Solar, LLC - Applications 

12900 Eckel Junction Rd 4050 E. Cotton Center Blvd, Bldg 6 Suite 68 

Perrysburg, OH 43551 Suite 69 Phoenix, AZ 85040 

Phone: (419) 872-7661 Phone:(602) 414-9300 

www.firstsolar.com www.firstsolar.com/ 

Engineering and Production: 

First Solar, LLC – Operations 

28101 Cedar Park Blvd. 

Perrysburg, OH 43551 

Phone: (419) 662-8500 

www.firstsolar.com/
iv

Abstract 

 Results of a 3+ year subcontract are presented. The research was conducted under 

Phase 5A2 of the subcontract entitled “Specific PVMaT R&D in CdTe Product 

Manufacturing”. The three areas of effort in the subcontract were 1) manufacturing line 

improvements, 2) product readiness, and 3) environmental, safety, and health programs. The 

subcontract consisted of three phases, approximately 1 year each. 

 Phase I included the development, design and implementation of a high-throughput, 

low-cost lamination process. This goal was achieved using the support of key experts such as 

Automation and Robotics Research Institute (ARRI) to identify appropriate lamination 

equipment vendors, and material handling. Product designs were reviewed by Arizona State 

University Photovoltaic Testing Laboratory and Underwriters Laboratory. Modifications to 

the module designs were implemented in order to meet future testing requirements. A 

complete review of the Environmental, Health and Safety programs was conducted along 

with training by the Environmental Protection Agency (EPA) and Occupational Safety and 

Health Administration (OSHA). 

 Work conducted during Phase II included the implementation of an improved potting 

procedure for the wiring junction. The design of the equipment focused on high throughput 

low cost operations. First Solar engaged industrial experts and vendors such as ARRI in the 

development, design and testing of alternative potting solutions which were directly scalable 

to 60 modules per hour with potential of exceeding that capacity with nominal upgrades. 

First Solar began the development of an improved scribing technique and design of 

associated equipment. A review of the process identified, throughput, labor, and equipment 

drawbacks. First Solar formulated an improved process through adaptation of state-of-the-art 

techniques and automation. This task resulted in the development of a high-throughput, lowcost scribing system increasing throughput by a factor of two; reducing downtime by a factor 

of three; and reducing equipment capital requirements by at least a factor of two. Product 

readiness efforts during Phase II included the initial testing of modules at Arizona State 

University Photovoltaic testing laboratory (PTL) and a review of design features such as: 1) 

junction box instead of pigtails; 2) sizes other than 60cm x 120cm; 3) alternative voltage; 4) 

alternate encapsulation materials or processes; and 5) other product changes influenced by 

market demand. Refinements were made to the EHS programs through the involvement of 

industry experts such as OSHA and On-Site Consultation of the Ohio Bureau of Employer 

Services. First Solar initiated improvements through a series of training and educational 

seminars for its employees affected by the targeted issues. Altogether over thirty different 

activities have been conducted in the EHS program over the period of the Phase II project. 

Among these activities were: development and implementation of fifteen EHS-related plans 

and programs; obtaining permits; generating reports to municipal and state agencies; 

conducting inspections; environmental sampling of R&D and production equipment and 

facilities for hazardous substances; installation and monitoring of EHS equipment; and 

periodic evaluation of employees for baseline cadmium. 

 During Phase III , First Solar made significant progress in three areas: Manufacturing 

Readiness, Product Performance and Environmental, Health and Safety (EH&S). First 

Solar’s accomplishments in laser scribing significantly exceeded the stated goals. 

Innovations implemented during Phase III include increasing the scribing speed from 70 
v

mm/s to 1700 – 3000 mm/s; achieving a throughput rate of 60 modules/hr for the three laser 

systems built for each of three scribes; decreasing the cost per system by a factor of two; 

decreasing significantly the kerf and spacing of the scribe lines, thereby increasing the active 

module area; increasing the laser life by a factor of 10 up to 10,000 hours and completely 

automating the scribing station, including loading, unloading, scribing, and focusing. These 

innovations were made possible by adopting a new type of high frequency, low-pulse-width 

laser, galvanometer-driven laser beam system, and numerous advanced, automated, 

equipment features. Because of the greater than one order of magnitude increase in the 

throughput and laser life, a factor of two decrease in equipment cost, and complete 

automation, a major impact on lowering the cost of the PV product is anticipated. 

 Testing has been successfully completed and all required documentation has been 

submitted to UL. Final approval from UL to use the listed label has been granted. The 

impact of the UL listing has allowed First Solar to begin its production. The product has been 

made commercially available. 

 First Solar obtained IEC 61646 certification, for its modified Module. This certification 

validates the First Solar product and enables the product to be marketed internationally. 

Detailed testing results are included as appendix 1 

 EH&S capabilities were significantly advanced through implementation of detailed and 

comprehensive programs in each area - Environmental, Health and Safety, and a detailed 

plan was developed to obtain ISO 14000 certification. First Solar maintains a safe and 

healthy work place as well as an environmentally friendly manufacturing process and 

product. 
vi

Table of Contents 

Table of Contents vi 

1. Introduction 1 

2. Summary 2 

3. Report Overview 4 

4. Phase I Task Overview 4 

Task 1 Manufacturing Line Improvements – Lamination 4 

Task 2 Product Readiness 4 

Task 3 Environmental, Health and Safety Programs 5 

4.1. Phase I Results for Task 1, 2, and 3 Milestones 5 

4.1.1. Task 1 Milestones---Manufacturing Line Improvements 5 

4.1.2. Task 2 Milestones---Product Readiness 10 

4.1.3. Task 3 Milestones---Environmental, Health and Safety Programs 12 

5. Phase II Task Overview 14 

Task 4 Manufacturing Line Improvements – Laser Scribing and Potting 14 

Task 5 Product Readiness 14 

Task 6 Environmental, Safety and Health Programs 15 

5.1. Phase II Results for Task 4,5,and 6 Milestones 15 

5.1.1. Task 4 Milestones---Manufacturing Line Improvements 15 

5.1.2. Task 5 Milestones---Product Readiness 34 

5.1.3. Task 6 Milestones---Environmental, Safety and Health Programs 44 

6. Phase III Task Overview 45 

Task 7. Manufacturing Line Improvements – Laser Scribing and Potting 45 

Task 8. Product Readiness 45 

Task 9. Environmental, Safety, and Health Programs 45 

6.1. Phase III Results for Task 7, 8, and 9 Milestones 46 

6.1.1. Task 7 Milestones---Manufacturing Line Improvements 46 

6.1.2. Task 8. Milestones---Product Readiness 48 

6.1.3. Task 9 Milestones--- Environmental, Safety, and Health Programs 58 

7. References 66
1

1. Introduction 

This is the Final technical report for the Specific PVMaT R&D in CdTe Product 

Manufacturing subcontract awarded to Solar Cells, Inc. (SCI) in 1998. Just prior to Phase II 

of the PVMaT project, major changes occurred in the company’s corporate structure. 

Beginning February 1, 1999 Solar Cell, Inc. (SCI) formed a joint venture partnership with 

True North Partners of Scottsdale, AZ. The new company was named First Solar, LLC. For 

brevity in this report, “First Solar” (or FS) is used to refer to all activities and 

accomplishments of SCI or First Solar, LLC. This event, resulted in an infusion of new 

financial resources and manpower toward the immediate start of construction of a new major 

manufacturing facility for photovoltaic modules, based on cadmium telluride. The site of the 

new plant is at Cedar Park Boulevard in Perrysburg, a suburb of Toledo, Ohio. The 

engineering plans for this facility were completed just prior to the formation of the joint 

venture. Equipment was originally designed to be capable of producing PV modules at a rate 

of 100 MW per year. A photo of the new First Solar PV module manufacturing facility 

appears in Figure 1. Because of the impending start of manufacturing activities scheduled for 

early 2000, the objectives were expanded as a result of continual reviews of the equipment 

and product design, to remove any potential bottlenecks in the overall manufacturing process. 

Figure 1. A photograph of the new First Solar Facility PV module 

Manufacturing plant in Perrysburg, Ohio 
2

2. Summary 

Summary of Major Accomplishments for Subcontract ZAX-8-17647-06 

Manufacturing Line Improvements 

All task milestones were successfully complete. There were three specific areas of focus; 

Lamination, potting/junction wiring, and laser scribing. 

A high through put lamination process was developed. Industry consultants including 

Automation and Robotic Research Institute (ARRI) and Product Search were engaged in the 

development of a lamination and potting process capable of producing 60 modules per hour. 

A low cost molded junction termination was developed and implemented. Automated inline 

simulator and wet hi-pot systems were developed and installed. Module performance data is 

obtained using this automated system. 

Research was conducted using liquid polyester resin, rubber EPDM, and Trueseal 

corporations hot melt butyl compound, in addition to or as a replacement for the current 

Ethyl Vinyl Acetate (EVA) encapsulant material. Research was conducted on replacement 

materials for the current tempered back cover glass and several potential materials were 

identified for the next generation product. This effort will be continued in order to develop a 

lower cost, higher moisture barrier back cover layer for the CdTe module. 

First Solar developed an improved high-throughput laser scribing system. The developed 

system is capable of scribing solar panels, measuring 120 cm x 60 cm, with a throughput of 

one per minute, at a reduced capital cost, improved reliability, improved scribe control and 

requiring the use of a single laser beam per each of three types of scribes. 

The system developed is capable of achieving a 60-cm-long scribe line, having a minimum 

theoretical spot size of 70 microns. Scribe-to-scribe location is easily controlled. The 

scribing can reach speeds in excess of 3400 mm/sec, through the use of pulsed lasers having 

a high rep-rate. A key benefit of this system is the ability to use a correction factor in the 

software, which allows cell mapping and correcting the focus for uneven surfaces. In order to 

achieve speeds above 2000 mm/sec, scribing through the glass side of the solar panel, 

reported earlier [2], was pursued. 

Green-light (532 nm) lasers are typically used for solar cell scribing in order to match the 

wavelength to the optical absorption of the material. In this project it was determined to use 

near-infrared (IR) lasers after developing the understanding that the CdTe absorption 

increases greatly with temperature for near-infrared (IR) wavelengths. 

Considering the structure of the solar panels, from the sunny side, it consists of a soda-lime 

glass plate superstrate, coated with layers of TCO/CdS/CdTe/metal, encapsulated by a 

second plate of glass. The TCO signifies transparent conductive oxide. In the scribing 

sequence used at First Solar, each scribe removes a smaller amount of material compared to 

its predecessor, thus the top-most layers can be removed at low energies without damaging 

the inner layers. Scribe-1 removes all the layers on the glass; scribe-2 removes the CdS and 

CdTe, without ablating the TCO. Scribe-3 removes the metal layer, applied after scribe-2; 

the metal is removed chiefly by the high-pressure CdTe vapor formed at its interface by the 

beam reflected by the metal. 

Improvements with the improved scribing system include: (1) Reduced capital cost - the cost 

of high-speed improved laser system is about 65% less than that of a conventional system, 
3

with four nozzles; (2) reduced and lower-cost maintenance, which reduces down-time by a 

factor of ten; (3) greatly enhanced location accuracy of subsequent scribes through the use of 

fiducials, coupled with automated correction for panel growth/ shrinkage caused by 

temperature variations as well as panel rotation; (4) substantially reduced kerf widths and 

scribe spacing, whereby the active area of the panel is increased; (5) IR lasers deliver about 

twice the power of frequency-doubled green lasers and have life expectancy of up to 10,000 

hours, 14 times greater than green lasers, and lower cost; and (6) increased production 

throughput by a factor of four. 

Product Readiness 

R&D activities were conducted to facilitate UL and IEC certification. These efforts included: 

(a) heat strengthening of glass to avoid breakage; (b) elimination of failures in the cord plate 

junction through the use RTV silicone potting material (c) relocation of the hole in the cover 

glass from 10 cm to 25 cm off the edge of the glass, thereby lowering the tensile stresses in 

the laminated module an average of 500 PSI; and (d) screening of alternative encapsulants to 

EVA to improve electrical insulation during damp-heat testing. 

At the start of Phase III First Solar PV modules received “recognition” from the Underwriter 

Laboratories, which allowed the modules to be used on listed mounting systems. 

During April 2001, and September 2002 modules were resubmitted to the Arizona Testing 

Laboratory with a c-channel and d-channel mounting system respectively. HF-10 and static 

load testing were successful and First Solar received authorization to use the UL Listed mark 

on its FS-50c and FS50d modules. These are complete modules with mounting attachments 

secured to the backside. The c, and d, designations indicate the style of mounting with the c 

denoting aluminum c-channel rails, and the d denoting aluminum d-channel rails. 

In October 2002, nine standard production modules were submitted for testing to the 

Photovoltaic Testing Laboratory (PTL) at the Arizona State University, in accordance with 

the IEC standards. First Solar modules have completed the certification testing in accordance 

with IEC 61646 and have obtained international certification. 

Environmental, Safety, and Health Program 

EH&S capabilities were significantly advanced through implementation of detailed and 

comprehensive programs in each area - Environmental, Health and Safety, and a detailed 

plan was developed to obtain ISO 14000 certification. Over thirty specific tasks were 

completed during this subcontract period. Among these tasks were: development and 

implementation of a personal protective equipment program, means of Egress plan, first 

aid/blood born pathogens training, electrical lockout/tag out training, light/noise/ ventilation 

evaluations, generation of reports to municipal and state agencies; equipment safety 

inspections; environmental sampling of R&D and production equipment and facilities for 

hazardous substances; installation and monitoring of EHS equipment; and periodic 

evaluation of employees for baseline cadmium. First Solar maintains a safe and healthy work 

place as well as an environmentally friendly manufacturing process and product. First Solar 

is continuing on plan to obtain ISO 14000 (or equivalent) certification. 
4

3. Report Overview 

This subcontract consisted of three separate phases. During each phase there were specific 

tasks relating to: Manufacturing Line Improvements, Product Readiness, and Environmental, 

Health and Safety Programs. These tasks were sequentially numbered and milestones were 

assigned for each task. 

Phase I 

 Task 1 Manufacturing Line Improvements 

 Task 2 Product Readiness 

 Task 3 Environmental, Health and Safety Programs 

Phase II 

 Task 4 Manufacturing Line Improvements 

 Task 5 Product Readiness 

 Task 6 Environmental, Health and Safety Programs 

Phase III 

 Task 7 Manufacturing Line Improvements 

 Task 8 Product Readiness 

 Task 9 Environmental, Health and Safety Programs 

In order to follow the efforts of this development subcontract, the report has been organized 

by the three Phases. An overview of the tasks is listed followed by the milestones and results 

for each milestone. 

4. Phase I Task Overview 

Task 1 Manufacturing Line Improvements - Lamination 

The specific objective of this task for Phase I was to develop, design and implement a highthroughput, low-cost lamination process with throughputs increased from 18 units/hour to at 

least 30 units/hour, labor costs reduced by 50% and equipment capital requirements lowered 

by a factor of four. This goal was to be achieved using the support of key experts such as 

Automation and Robotics Research Institute (ARRI) to identify appropriate lamination 

equipment vendors, material handling solutions and establish parameters for its integration 

on the First Solar production line. Besides demonstrating laminator throughput of 30 

modules/hour, improved lamination preparation techniques including EVA cutting and 

application, bus bar application, and back glass handling and application were included in 

this work. 

Task 2 Product Readiness

The specific objective of this task was to qualify First Solar’s current module design 

according to protocols of IEEE 1262 and UL 1703 and achieve certification from Powermark 

Corporation; a worldwide recognized PV module certification for product durability and 

performance. 

Note: During Phase III the certification requirements were revised to include IEC 61646 and 

UL 1703 only. IEEE 1262 was no longer in effect at the end of the project. In addition, 

references to IEC 1215 should also be considered as requiring IEC 61646. IEC 61646 was 
5

developed specifically for Thin-film Photovoltaic modules, where IEC 1215 was intended 

only for Crystalline Silicon photovoltaic modules. 

Task 3 Environmental, Health and Safety Programs

The specific objective of this task was to continue and improve First Solar’s environmental, 

health and safety programs initiated during its PVMaT Phase 2B subcontract. An internal 

review of current programs was to be conducted and, using the assistance of industry experts, 

their status relative to industry best practices assessed. 

4.1. Phase I Results for Task 1, 2, and 3 Milestones 

4.1.1. Task 1 Milestones---Manufacturing Line Improvements 

m-1.1.1 Initiate development program by interviewing key supplies and 

experts such as STR, Inc., ARRI, and automotive glass 

manufacturers 

(Task 1) 

m-1.1.2 Complete process specification for high throughput laminator (Task 1) 

m-1.2.1 Complete design specification for high throughput laminator (Task 1) 

m-1.3.1 Begin debug of high-throughput laminator (Task 1) 

m-1.4.1 Complete prove-in of high throughput laminator at a rate of thirty 

modules per hour 

(Task 1) 

m-1.4.2 Complete report on lamination rates, yields, and reductions in labor 

and equipment costs 

(Task 1) 

m-1.4.3 Complete the Phase I portion of the effort under Task 1 (Task 1) 

Milestone Description 

m-1.1.1 Initiate lamination development program by interviewing key suppliers and experts 

such as STR, Inc., ARRI, and automotive glass manufacturers 

This milestone was completed successfully. Though the PV industry on the whole has 

adopted the one atmosphere, bag style vacuum laminator, high throughput applications such 

as automobile windshield glass manufacturers have always used autoclaves for mass 

production of laminated glass. First Solar, based on outside and inside expertise and 

experience, abandoned the home-built bag style vacuum laminator and purchased an 

autoclave for high volume, low cost lamination of CdTe thin-film PV modules. Additionally, 

after some delay due to negotiating intellectual property rights, a contract was signed with 

Automation Robotics and Research Institute to address lamination preparation process 

improvements aiming to align module assembly tasks time and labor with the improvements 

anticipated by using the autoclave instead of the bag laminator. 

Milestone Description

m-1.1.2 Complete process specification for high throughput laminator 

This milestone was completed successfully. A series of manufacturing experiments were 

undertaken using the same materials and assembly lay-up procedure as used for the 

abandoned vacuum press style laminator. Embedded thermocouples were used to monitor 
6

temperature of the laminate interlayer (EVA) for comparison to Springborn (EVA 

manufacturer) recommendations. Pressure was tracked using the on-board chart recorder of 

the autoclave. 

Ultimately, a lamination process cycle as described below was developed. The total cycle 

time for a batch of up to 24 module units is 45 minutes, resulting in the targeted hourly 

throughput rate of up to 30 units per hour. 

This cycle resulted in surprisingly good “gel content” results, a measure of EVA 

polymerization. Chart 1 shows the typical gel content for EVA as reported by Springborn for 

vacuum press laminators compared to the gel content achieved by the First Solar Autoclave. 

A higher gel content result indicates a higher degree of polymerization; implying improved 

EVA polymer adhesion and stability. Another improvement resulting from the superior 

performance of the autoclave is the lack of entrapped air bubbles in the EVA laminate film. 

Previously, all modules laminated in the vacuum press laminator had small air bubbles 

trapped particularly in the edge deleted (bonding) area of the unit; these are absent from 

autoclave laminated modules. 

Chart 1: 

Autoclave Operating Conditions 

Milestone Description

m-1.2.1 Complete design specifications for the high throughput laminator 

This milestone was completed successfully. Figures 2 and 3 show the high throughput 

laminator design as proposed and as installed. 

Figure 2: High-throughput laminator as proposed 

0

50

100

150

200

0 10 20 30 40 50

Time (min)

Temperature (C)

0

2

4

6

8

10

12

14

16

Pressure (psig)

Temp.

Pressure
7

Additional sub-tasks to develop high-throughput, labor reducing, material saving lamination 

preparation equipment were submitted by ARRI and approved and initiated by First Solar. 

As pointed out in the Overview, this equipment is necessary to maintain productivity in the 

module assembly stage of the lamination operation equivalent to the high-throughput 

autoclave laminator. 

These subtasks were defined as: 

Figure 3: High-throughput 

laminator as installed. 
8

Ö “As-is” analysis of the final module assembly process 

Ö Process and material handling vendor search 

Ö “To-be” concept designs for final module assembly 

Ö Simulation model development 

Ö Process development 

Ö Material handling development 

Ö Quarterly reviews 

Ö Integration and test 

Ö System set-up, testing and training 

Milestone Description

m-1.3.1 Begin de-bug of high-throughput laminator 

This milestone was completed successfully. There were two significant problems 

encountered when production module lamination using the autoclave began. First, since the 

autoclave process cycle requires a total pressure of about 2 atmospheres (~ 1.5 atmosphere 

from the initial air removal step when the module is placed in a plastic de-airing bag and 

another applied atmosphere from the autoclave for bubble-free laminations), yield fall-off 

from breakage increased compared to the old vacuum press style laminator. Second, direct 

material costs increased compared to the old laminator because a host of materials to contain 

the assembled module under vacuum were needed for initial de-airing including release film, 

woven breather material, tape and the plastic vacuum bag. To clarify this point, the 

autoclave process is not a pressure process only. Initial de-airing of the module assembly 

must occur before pressure is applied to remove entrained air; flexible, elastomeric vacuum 

rings and nip rollers are alternative de-airing processes. 

Clearly, though the laminator throughput objective of 30 units/hour was met, increased yield 

fall-off and direct materials costs were not acceptable. 

Consultation with Springborn yielded the suggestion of trying a textured, rather than 

smoothly finished EVA. This simple material change, actually just a change of the laminate 

film surface, solved both the yield fall-off problem and the increased direct material costs 

problem at once. By switching from smooth to textured EVA, de-airing becomes much more 

efficient. Because more air is removed earlier in the autoclave cycle, the pressure applied 

during the pressure part of the cycle can be reduced. The process was modified to reduce the 

applied autoclave pressure from 1.5 to 1 atmosphere (15 PSI) using textured EVA laminate 

film. This, along with a slight modification to the bus-bar ribbon connection (to reduce the 

total thickness at the end bus bar) essentially eliminated yield fall-off from breakage. 

Addendum II shows the results of a controlled experiment to document yield fall-off 

improvement. 

Again, because de-airing is more efficient using textured EVA, this allowed adopting a reusable, silicon elastomer vacuum ring to effectively de-air the module assembly. When the 

rings were tried without the textured EVA, incomplete de-airing occurred and bubbles 

remained after lamination. In conjunction with a back-glass bus bar exit hole sealing 

technique such as using either an epoxy pre-potting or simply a silicon suction cup, textured 

EVA allowed the elimination of all the described disposable direct materials. This cost 
9

reduction reduced direct material costs by nearly $10 per unit, a substantial percentage 

decrease of total direct costs. 

Work continued this quarter by ARRI on the lamination assembly automation equipment. 

Several options with various degrees of automation were studied. 

Milestone Description

m-1.4.1 Complete prove-in of high-throughput laminator at a rate of thirty modules per 

hour. 

This milestone was completed successfully. Fixtured for 24 modules (rather than the ten slot 

fixture that came with the autoclave), and a cycle time of 45 minutes, a laminator throughput 

of 30 modules/hour is achieved. Additionally, the autoclave installed and evaluated by First 

Solar is comparatively small. Autoclaves are available in sizes that allow lamination of First 

Solar’s 60cm x 120cm modules on the scale of hundreds of units per cycle. 

Milestone Description

m-1.4.2 Complete report on lamination rates, yields, and reductions in labor and equipment 

costs. 

This milestone was completed successfully. The throughput rate was concluded and reported 

on in milestone m-1.4.1 above. The cycle time per unit for the vacuum press laminator was 

about 20 minutes; that has been reduced to a per unit cycle time of 2 minutes, or a full order 

of magnitude, using an autoclave fixtured for 24 units and a 45 minute cycle time. 

A larger scale yield investigation is planned but a preliminary study documented as 

Addendum II shows a yield fall-off improvement from 10% before implementing the 

textured EVA and elastomeric vacuum ring system to a negligible level after implementing 

it. 

Since one person was required to operate the bag laminator and one person is required to 

operate the autoclave (actually the autoclave operator can leave the machine unattended 

during the lamination cycle), a labor savings comparison is straightforward. If the 20 minute 

cycle time for the bag laminator is one labor unit, and the autoclave can produce the 

equivalent of 10 units in 20 minutes, an order of magnitude reduction in labor has been 

achieved (90% labor reduction). This is significantly better than the stated 50% labor 

reduction in the Task 1 goal. 

Last, the capital equipment objective for this task was a factor of four reduction. A leading 

supplier reports a state-of-the-art bag laminator costs $285,000. McGill autoclave reports a 

5’ x 10’ autoclave, fixtured for twenty-four 60cm x 120cm modules costs roughly the same 

($250,000). For the same amount of capital, throughput increases 10 times, resulting in a ten

times reduction in unit related capital costs. This is better than the factor of four objective. 

Milestone Description

m-1.4.3 Complete the Phase I portion of the effort under Task I. 
10

This milestone is complete. Complimentary work is underway by ARRI to complete the 

module assembly automation equipment that will allow the 30 module/hour throughput target 

required to support the autoclave laminator. Several recent ARRI status reports are attached 

as Addendum III showing the progress for automation equipment design and testing. The 

semi-automated prototype lamination preparation station will be completed by ARRI in June 

and First Solar will demonstrate the 30-unit/hour throughput, scaleable to 60 unit/hour at that 

time. 

4.1.2. Task 2 Milestones Product Readiness 

m-1.1.3 Initiate contact with module testing laboratory and complete 

preliminary module design review 

(Task 2) 

m-1.2.2 Complete preliminary testing of modules (Task 2) 

m-1.2.3 Establish qualification testing schedule (Task 2) 

m-1.3.2 Initiate qualification testing on First Solar’s standard module (Task 2) 

m-1.4.4 Complete qualification testing on First Solar’s standard module for 

IEEE 1262, IEC 1215, and UL 1703 

(Task 2) 

m-1.4.5 Complete the Phase I portion of the effort under Task 2 (Task 2) 

Milestone Description

m-1.1.3 Initiate contact with module testing laboratory and complete preliminary 

module design review. 

This milestone was completed successfully. The Arizona State University Photovoltaic 

Testing Laboratory was contacted and chosen as the module testing laboratory. The ASU lab 

is nationally and internationally recognized as a reliable PV testing facility. Certification is 

provided through PowerMark Corporation. European equivalence is provided through 

simultaneous testing to IEC 1646 protocols. 

Preliminary module design review was also completed. The First Solar “SPN-7” modules 

designated for testing were unchanged from previous designs except that the front substrate 

was changed from 5mm to 3mm thickness (for weight and cost savings). 

Milestone Description

m-1.2.2 Complete preliminary testing of modules. 

This milestone was completed successfully. Modules made using the new 3mm thick glass 

substrate were manufactured, tested and approved for initial performance. By decreasing the 

front substrate thickness from 5 to 3mm, Jsc improved due to more usable photons reaching 

the semiconductor rather than being absorbed in the glass substrate. 
11

Chart two shows a moving average trend line indicating the clear improvement in Jsc as the 

3mm substrate glass was introduced. The improvement in Jsc paves the way for overall 

efficiency improvements for a given TCO front-contact resistivity. 

Milestone Description

m-1.2.3 Establish Qualification Testing Schedule 

This milestone was completed successfully. Twelve First Solar “SPN-7” modules were 

shipped to the Arizona State University Photovoltaic Testing Laboratory on August 25, 1998 

and received by ASU in early September. A completion date of January 1, 1999 was 

predicted by ASU. 

Milestone Description

m-1.3.2 Initiate qualification testing on First Solar’s standard modules. 

This milestone was completed successfully. Qualification testing was actually initiated 

ahead of schedule in the last quarter (4th quarter 1998). 

Milestone Description

m-1.4.4 Complete qualification testing on First Solar’s standard module for IEEE 1262 and 

UL 1703. 

Chart 2

Jsc Comparison - September 1 to December 10, 1998

15

16

17

18

19

20

0 100 200 300 400 500 600 700

Unit Number

Jsc

Jsc

20 per. Mov. Avg. (Jsc)

5 mm front 

3 mm front 
12

This milestone is complete. Qualification testing was completed in April and a final test 

report is awaited from the ASU Photovoltaic Testing Laboratory. First Solar’s “SPN-7” has 

passed IEEE 1262 Sequence “A” testing (200 thermal cycles), Sequence “B” up to heathumidity-freeze cycling, Sequence “C” up to damp heat testing and Sequence “F”. The 

outcome of the damp heat test was initially unclear and delayed due to problems with a 

contaminated test chamber where the SPN-7 modules were first tested. A repeat test yielded 

a marginally below standard result (slightly more than allowable performance degradation). 

Testing under UL 1703 has not been completed under this task; it will be completed after 

IEEE1262 is passed. 

Now, the task for Phase II becomes more involved because significant module encapsulation 

processes and product design changes will have to be made to ensure certification of IEEE 

1262 on the next qualification attempt scheduled for Phase II of this work. The module 

potting system and moisture edge barrier will be the focus of this work, as well as 

understanding surface preparation techniques to maximize adhesion of the laminate material 

and consideration of alternative encapsulants. 

Milestone Description

m-1.4.5 Complete the Phase I portion of the effort under Task 2. 

This milestone is complete. Work is underway to modify materials, processes and product 

design to ensure passage of all IEEE 1262 and UL 1703 requirements in Phase II of this 

work. 

4.1.3. Task 3 Milestones--- Environmental, Health and Safety Programs 

m-1.1.4 Complete review and survey of current ES&H programs (Task 3) 

m-1.2.4 Develop plans for critical areas of ES&H improvement with the 

assistance of industry experts such as OSHA On-Site Consultation 

(Task 3) 

m-1.3.3 Initiate EH&S improvement projects (Task 3) 

m-1.4.6 Complete implementation of critical ES&H improvements (Task 3) 

m-1.4.7 Complete the Phase I portion of the effort under Task 3 (Task 3) 

Milestone Description

m-1.1.4 Complete review and survey of current environmental, health and safety 

(EHS)programs. 

This milestone was completed successfully. In addition to an in-house review of current 

EHS programs by the EHS manager, an EHS Technician support position was created and 

filled. This individual attended two comprehensive seminars related to EPA (Environmental 

Protection Agency) and OSHA (Occupational and Health Administration) compliance in 

order to gain information and plan for improvement during the second quarter of this task. 

The review included not only compliance related programs but a review of internal safety 

rules and procedures as well as industrial ventilation equipment and related engineering 
13

controls for worker exposure to cadmium compounds and volatile organic hydrocarbons 

(VOC’s). 

Milestone Description

m-1.2.4 Develop plans for critical areas of EHS improvement with the assistance of 

industry experts such as OSHA On-Site Consultation. 

This milestone was completed successfully. Though OSHA On-Site Consultation services 

was not used, the EHS Manager and EHS Technician, using information from the Internet 

and recent EHS workshops, created a comprehensive EHS improvement process plan. The 

EHS improvement planning process was broken down separately for all three environmental, 

health and safety elements into strictly compliance program development and best 

management practices and activities. To save repetition, the EHS plan and First Solar’s 

record of completing the plan (according to milestone m-1.4.6) are attached as Addendum I. 

Milestone Description 

m-1.3.3 Initiate EHS improvement projects 

This milestone was completed successfully. Similar to milestone m-1.3.2, EHS improvement 

projects were actually initiated ahead of schedule in the second quarter (refer to Addendum I 

for the project schedule). 

Milestone Description

m-1.4.6 Complete implementation of critical EHS improvements. 

This milestone has been completed successfully. The EHS improvement program 

improvement process has followed the schedule outlined in Addendum I. Results are 

indicated there. 

Safety and health highlights include the improvement of local ventilation controls for 

cadmium in the edge deletion, laser and cadmium chloride application processes, the 

implementation of a comprehensive lockout-tag out program in conjunction with electrical 

safety training, first aid, blood borne pathogens and CPR training, material handling and fork 

truck training and a revised respirator training program. 

Complete facility mass balance emissions calculations were done to demonstrate compliance 

with environmental regulations and requirements. 

First Solar’s current lost workday rate is 13.3 and lost workday case rate is 8.3 for the Phase I 

project period (May 1998 through April 1999). This corresponds to 32 for lost workdays and 

6.8 for lost workday cases in the electronics-manufacturing sector for the last year data is 

available (1996). This shows that, while First Solar experienced an 18% higher accident rate 

than the electronics-manufacturing sector for the period, the severity was 140% lower. 

Improvements will be achieved as safety awareness training becomes more routine. 
14

Milestone Description

m-1.4.7 Complete the Phase I portion of the effort under Task 3. 

As noted above, this milestone has been successfully completed. 

5. Phase II Task Overview 

Task 4 Manufacturing Line Improvements – Laser Scribing and Potting 

First Solar, LLC (First Solar) shall develop and implement an improved potting procedure 

and design associated equipment. First Solar shall conduct a thorough review and analysis of 

the current process to identify throughput, labor, and equipment drawbacks. First Solar shall 

formulate an improved process through adaptation of well-proven glass manufacturing 

methods and automation. First Solar shall engage industrial experts and vendors such as the 

ARRI as needed in the development, design and testing of alternative potting solutions which 

are directly scalable to 60 modules per hour with potential of exceeding that capacity with 

nominal upgrades. First Solar shall complete off-line development of the individual potting 

processes such as diode connection, mold positioning, and urethane injection. First Solar 

shall carry out the prototyping of material handling steps for the potting process such as: 

handling large sheets of glass in and out of buffers; feeding glass in and out of the potting 

work station; flash tests; and parts-feeding. First Solar shall test a prototype potting station to 

demonstrate the improvement elements and provide functional information for the highthroughput design. First Solar shall complete testing of the improved high-throughput 

potting system, including process and material handling components, on its module 

production line. The task is expected to result in high-throughput, low-cost potting by 

increasing throughput per potting line by a factor of at least four; reducing labor costs by at 

least a factor of ten; and increasing overall quality. 

First Solar shall also implement an improved scribing technique and design associated 

equipment. First Solar shall conduct a thorough a review of the current process to identify 

throughput, labor, and equipment drawbacks. First Solar shall formulate an improved 

process through adaptation of state-of-the-art techniques and automation. First Solar shall 

engage industrial experts and vendors such as the ARRI as needed in the design, and testing 

of the new scribing technique to expedite task progress. The task is expected to result in 

high-throughput, low-cost scribing by increasing throughput by a factor of two; reducing 

downtime by a factor of three; and reducing equipment capital requirements by at least a 

factor of two. 

Task 5 Product Readiness 

First solar, LLC shall initiate and complete qualification testing of a modified module. 

Modifications may include one or more of the following depending on the market interest: 1) 

junction box instead of pigtails; 2) sizes other than 60cm x 120cm; 3) alternative voltage; 4) 

encapsulation materials or process; and 5) other product changes influenced by market 

demand. First Solar shall obtain UL1703 certification for its modified module. Experts from 

the field including Underwriters Laboratory and the Photovoltaic Testing Laboratory at the 

Arizona State University will be utilized as needed to expedite the successful completion of 

the task. The task is expected to improve acceptance into existing and new markets. 
15

Task 6 Environmental, Safety and Health Programs 

First Solar, LLC shall continue to refine and improve its Environmental, Safety, and Health, 

(ES&H) programs throughout its facilities. First Solar shall conduct an extensive review of 

its current programs and highlight areas that need improvement. First Solar shall employ 

industry experts such as OSHA On-Site Consultation of the Ohio Bureau of Employer 

Services to expedite progress on improvements and provide guidance for plan 

implementation. First Solar shall initiate improvements through a series of training and 

educational seminars for its employees affected by the targeted issues. First Solar shall 

complete the implementation of refinements and improvements in critical areas and establish 

a plan for continuous improvements in its entire program. This task is expected to result in 

an Environmental, Safety and Health program which ultimately will place First Solar in a 

leadership position relative to comparable businesses both within and outside of the 

photovoltaic industry 

5.1. Phase II Results for Task 4,5,and 6 Milestones 

5.1.1. Task 4 Milestones--- Manufacturing Line Improvements 

m-2.1.1 Complete thorough review of potting preparation and potting 

processes including time studies; equipment utilization; materials 

yield; and flow 

(Task 4) 

m-2.2.1 Complete potting improvement plan including methodology and 

resource allocation 

(Task 4) 

m-2.3.1 Complete initial testing of potting process improvements (Task 4) 

m-2.4.1 Complete demonstration of improved potting process (Task 4) 

m-2.4.1b Complete thorough review of laser scribing process including 

parameter flexibility, capital costs, and cycle time 

(Task 4) 

m-2.4.2 Complete the Phase II portion of the effort under Task 4 (Task 4) 

Milestone Description 

m-2.1.1 Complete thorough review of potting preparation and potting processes including 

time studies, equipment utilization, materials flow, and yield 

As a result of combined team activities of First Solar and Product Search, Inc., this milestone 

was completed successfully. An account of these activities follows. The objectives of the 

potting task in Phase II were to: 

3⁄4 increase manufacturing throughput by a factor of four, 

3⁄4 reduce labor costs by a factor of ten, 

3⁄4 increase overall quality. 

In May 1999, at the Solar Finishing Line Concept Design Review the results of the module 

qualification task for Phase I PVMaT were reviewed. A round of modules had been 

submitted for qualification to Arizona State Photovoltaic Testing Laboratory for IEEE 1262 

Testing. Those modules failed two of the four sequences, the humidity-freeze test and the 

damp-heat test. From this report it became apparent that the polyurethane potting method 

for the electrical contact termination and for the molding of mounting pads may have to be 
16

replaced, in order to achieve the goals of environmentally durable device, a high-throughput 

manufacturing process and a cost-effective product. 

In response to that, from the beginning of Phase II several alternative module finalization 

schemes have been evaluated toward achieving the Phase II qualification objective. Three 

possible solutions have been investigated simultaneously or in close sequence starting in June 

1999. 

Figure 4. Photographs of potted polyurethane termination “pigtails” and mounting 

pucks on the rear of PV modules—(a) a close up of the potted parts and 

(b) a view of the whole module.

A practical alternative method of mounting has been identified, patented by PowerLlight, 

Inc. This method, developed for a horizontal mounting on rooftops, utilizes the modules

bonded to a solid foam material and interlocked together, much like a puzzle, in cushioned 

frames. This method does not require either mounting pads or fastening of the modules to 

the frame. Several other sketches have been made for alternative mounting but thus far none 

have been selected for development, pending successful development of contact termination. 

Molded urethane 

mounting “puck” with 

molded “T”-nut. 

Molded urethane potting “puck” with 

molded in wire pigtails and diode.

Back of module; overall view. 
17

Contact Termination 

The Top-Hat design for contact termination 

In considering the projected production line improvements, potential cost-reduction measures 

have been identified in potting, labor and material and increased throughput. The Top-Hat 

design was one of the items where sizeable cost reductions appeared to be achievable by 

eliminating the potting process both for the termination and the mounting pads. For the 

electrical termination a small, injection-molded part called the Top Hat was designed and its 

development was initiated. The Top Hat is an electrical connector fixture made of polymeric 

material as shown in a photograph in Fig. 5. 

The Top-Hat design was intended to replace the potted polyurethane termination shown in 

Fig. 4a that uses wire termination, referred to as “pigtails.” It uses metallic “spade” terminals 

that are soldered to the two metallic strip conductors. In this design, the bottom rim of the 

Top-Hat fixture would fit underneath the cover glass. The fixture is affixed to the module by 

means of EVA pressure lamination. The Top-Hat connector and method were designed for 

high-throughput production of PV modules, low cost, and simplified method of installation 

of the modules in the field. 

Figure 5. A photograph of the “Top-Hat” termination fixture 
18

Milestone Description 

m-2.2.1 Complete potting improvement plan including methodology and resource 

allocation 

The plan for potting improvement, now called contact termination, was initiated during the 

2nd quarter of 1999 and completed during the 3rd quarter as described below. For testing of 

the Top-Hat concept in finished modules, prototypes of the Top-Hat fixtures were NCmachined of phenolic material. In eventual production, the fixtures would be made by 

injection molding. Testing of assembly fixturing was done first, to facilitate the attachment 

of the lead wires to the Top-Hat connector and of the resulting assembly to the double-sided 

tape that’s on the module. A total of over 25 modules have been made incorporating the 

Top-Hat connector. These modules were intended to be submitted for UL testing, following 

in-house testing. 

The second half of the Top-Hat fixture design is a matching connector, which was to be 

fabricated following the planned testing. 

On August 26, 1999 preliminary product specifications, including drawings were submitted 

to UL for their preliminary review and evaluation. In this process UL conducts an 

“Engineering Evaluation,” of the documentation and attempts to form a visual picture of the 

product, what the components are and how it’s put together. Then UL provides a feedback 

based of potential problems and issues. 

Following the fabrication of the modules using the Top-Hat connector for termination, the 

devices were subjected to damp-heat tests, which were completed in October. Some 

problems with the pottant have been identified. The potting that was being used for the TopHat insulation, a RTV silicone, was failing under strain relief testing. This problem was due 

to the size of the termination cavity, being potted to provide the strain relief. It was also too 

thick and the RTV would require an unacceptable curing time. Otherwise, from the 

standpoint of moisture-proofing, RTV tested to be satisfactory. Nevertheless, the Top-Hat 

design was abandoned and replaced by a new termination design, named the “Cord-Plate”

design, wherein the stress-relief failures were expected to be eliminated. Sketches of the 

Cord-Plate termination design are shown in Figures 4 and 5 of Milestone m-2.3.1 Section. 

UL report on “Results on Preliminary Investigation” for the Top-Hat design 

Some memos and documentation has been received from UL throughout October regarding 

the Engineering Evaluation of the product specification and module mockup submitted in 

September. A preliminary report was received from UL in mid-November called “Results on 

Preliminary Investigation,” which is included in the monthly reports. It contains extensive 

evaluation, their comments and the feedback they gave us. The report contained mainly 

comments related to product materials used in the Top Hat, to passing product flameretardant tests, other issues about thermal testing, and more on flame retardant materials, and 

thermal tests to which all the materials and modules were to be subjected. 

A major issue that UL raised that the mounting method for the module had not been 

submitted. Without the mounting method, all that UL could provide was only with 

“Recognition” of the PV module and not an actual listing. In order to get the listing, the 
19

complete package must be submitted, including the mounting method, termination and all 

aspects of finalization. Reading of the entire report prior to future submission is advised. As 

stated above, the initial submission included the Top-Hat termination design. However, in 

November timeframe some strain-related problems were discovered with the Top-Hat design. 

On November 11 a memo was sent to UL to have the test postponed. It was anticipated that 

the submission to UL would be made in January 2000 following the fabrication and in-house 

testing of modules incorporating the new Cord-Plate design. 

Milestone Description 

m-2.3.1 Complete initial testing of potting process improvements 

This milestone was completed with success. Two major accomplishment were achieved, one 

in successful testing of a new module design with “Cord-Plate” contact termination and the 

construction, installation and initial testing of the solar finishing line for the 

The Cord-Plate termination design 

In going over a possible redesign of the Top Hat, a decision was made to pursue a new 

design, the Cord-Plate design to circumvent the problems posed by the Top-Hat design. 

Work on the Cord-Plate design began on November 15, 1999. Thus, once again, a new line 

layout was developed for the termination process. It involved the design of a new electrical 

connection fixture, shown in Fig. 6, and the use of EVA as the encapsulant for the lamination 

of the module. Prototypes of the Cord Plate were made by NC machining, using a polymeric 

material. Incorporation of the Cord Plate in the modules was done by attaching it to the 

module by means of Very High Bond (VHB) adhesive tape, a 3M product. The VHB tape 

that is currently used to attach the Cord Plate to the surface of the module is 3M # 4941-F, 

0.046-inch thick. The potting material used to pot all of the termination locations is 3M # 

3748-VO-Q JET-MELT. The new design utilizes MC (Multi-Contact Corp.) connectors. 

 

Then a potting material 3M # 3748-VO-Q JET-MELT is used to all of the termination 

locations. The new design utilizes MC (Multi-Contact Corp.) connectors. The new design 

also made use of the FC connectors. The manner in which the Cord Plate is incorporated on 

the rear of the PV module is shown in Fig. 7. Following the fabrication of PV modules using 

the Cord Plate, in-house testing of the product was conducted. The tests included the dampheat, humidity-freeze tests, followed by the hi-pot tests, and the current leakage tests. The 

high-pot and the current-leakage tests were the most stringent tests that had to be passed. 

One of the main concerns was whether the VHB adhesive would withstand the 

environmental tests. 

Prototypes of the Cord Plate were fabricated by NC machining from a suitable polymer. It is 

planned, that in production, these components will be made by injection molding. The parts 

were then used as electrical connectors for termination in PV modules. 
20

Figure 6. A sketch of the “Cord-Plate” contact termination fixture 

Figure 7. Photograph of the “Cord-Plate” termination fixture, including the 

power-lead strain relief, incorporated in a module 

As stated previously, EVA was used as an encapsulant in the lamination of the modules. The 

modules have been fabricated through a collaborative effort between First Solar in Toledo 
21

and Product Search, Inc., in Scottsdale. The finished modules were sent to the Arizona State 

University (ASU) test lab for UL listing application testing. 

Initial test results indicated that all the modules came out of the damp-heat test thermal 

chambers, with no breakage, and they went into the dry hi-pot, the humidity-freeze cycle test 

all passed. The modules also performed well in the wet hi-pot test, and with only one failure 

of a total of 24 modules sent. From previous experience, passing of the wet hi-pot was the 

biggest concern as indicated. There was only one minor item that required a change for 

power-lead strain relief, which was accomplished successfully shortly thereafter. 

This accomplishment marks the completion of the front half of the finishing-line project, 

which includes the buss bar application, laying down the EVA, installing the back glass, 

putting on the silicone rings and getting it to the point where it goes into the oven or 

autoclave for encapsulating. There was a good indication that this process can be 

accomplished on the production line. 
22

Design, construction and installation of the Cord Plate and contact termination 

assembly lines (A report by Product Search, Inc.) 

As reported in Task 5, there are positive indications that the latest product design using the 

Cord-Plate termination method was expected to pass the UL testing. This news enabled all 

line assembly methods and automation design efforts to proceed at full speed. A final 

installation and start-up date in the new Cedar Park facility was established as April 10 thru 

April 28 of 2000. 

Product Search, Inc. shipped the pre-lamination (buss bar, EVA, back glass and seal ring) 

assembly line the last week of Feb. 2000 and installed it in the Cedar Park facility the week 

of March 5th 2000. 

All efforts were focused on the completion of the Cord-Plate assembly and contact 

termination assembly lines. This phase of the project also incorporated automated hi-pot 

testing and solar simulator testing with a production throughput rate of one module per 

minute. Coordination efforts with Vortec Industries as manufacturer of the simulator and 

Product Search as automation integrator were completed. 

Product Search has completed the design and construction of the Cord-Plate assembly and hipot and solar simulator test equipment in Scottsdale, AZ. The planned shipment, installation 

and start-up is April 11 through April 28, 2000. Some documentation activity (i. e., manuals, 

drawings, etc.) was scheduled to continue for a few days in May 2000. This installation will 

conclude the activity of Product Search, Inc. in Phase II of the project. Quotes have been 

provided for an additional solar simulator at the submodule line. Completion and installation 

of the solar finishing line 

Product Search completed the engineering design and build of the SOFL (solar finishing line) 

project at the Scottsdale, Arizona location. Limited operation of equipment and assembly 

tables was performed to debug equipment functions and assembly methods. However, a more 

intense debug test run of equipment operation was planned upon the completion of its 

installation at First Solar in Toledo. As stated earlier, Product Search shipped the prelamination assembly line and installed it in the First Solar facility during the last week of 

February, 2000. The remaining equipment, identified as the "Cord-Plate assembly", "I-V test 

station” (solar simulator), and "Hi-Pot station" were shipped and received on April 14th. 

Product Search personnel were on site at First Solar on April 17 through April 28, 2000. 

Installation and initial start-up of the equipment was completed. Photos of various parts of 

the new solar finishing line are shown in Figures 8, 9, 10 and 11. Because of the late 

delivery of the Vortec I-V test equipment, time did not allow for adequate operator training 

and pre-production operation of the equipment. A second trip to First Solar for actual start up 

and operator training was planned for later May 2000. At that time operator manuals and 

electronic data-base files were to be transferred. 

Upon completion of the training, Product Search Inc. will have completed involvement with 

this phase of the project with exception of service support or other tasks requested by First 

Solar. The completed task, which meets the initial goals, was to design and build an 

effective and safe production process. Baseline production throughput and associated labor 

cost will need to be monitored to evaluate actual process improvement. 
23

Figure 8. EVA sheet application station before lamination – 

start of solar finalization line 

Figure 9. Hi-Pot testing station after lamination 
24

Figure 10. Cord-plate contact termination application line 

Figure 11. Current-Voltage (I-V) test station, solar simulator 

Milestone Description 

m-2.4.1 Complete demonstration of improved potting process 
25

Module Finalization 

In May, the activity consisted of preliminary testing of the lamination process, using rejected 

modules for the purpose of determining yield and cosmetic quality. The yield on 20-plate 

batches was 95 percent for things like voids, bubbles in EVA and module breakage. In June, 

the next step was to undertake module production, using good quality submodules. For the 

past two weeks, good sub-modules were being processed up through lamination, 20 modules 

per day. The modules were used for test purposes—in preparation for passing the IEEE test. 

High yield was demonstrated with the processed modules. One of the items of interest was 

to determine what effect the heat in the lamination process had on the module efficiency. In 

the Westwood plant, where autoclave was used, the typical decrease in efficiency was 0.4% 

(absolute) of the module efficiency, equal to a decrease of about 5 W per module. What has 

been demonstrated using the new lamination process at the new Cedar Park plant, with 

relatively few modules, was that the decrease in efficiency was only 0.1 to 0.2 %. This 

improvement is attributed to a more stable cycle, being run at a slightly lower rate, with no 

overheating of the modules. There is no temperature uniformity problem that the autoclave 

had. More tests are needed to establish confidence in this conclusion. 

Majority of these modules have not gone through the Cord-Plate processing, because they 

were consumed in other tests, which did not require the Cord Plate. In this time frame (June 

2000) the Cord-Plate process was not in operation because the second half of the line was 

down on account of the hi-pot tester not performing reliably. These problems were being 

addressed as well as those of the automated I-V test station. There were also some hardware 

problems that are being rectified working with the vendor. 

In July the status of the solar finishing line has not changed since June. The rate of module 

lamination has remained constant (100/week). Problems have occurred with the software of 

the automated I-V testing station, which required sending the modules for testing to the old 

pilot plant at Westwood. Some problems have also occurred with buffing of the glass side, 

edge deletion, and delamination of the plates which are being resolved as part of de-bugging 

of the manufacturing process. 

Repair of the test station was completed by mid August. At this point the production rate 

was increased to 200 modules/week (40-hour week). Thereafter plans are to ramp up 

production on a monthly bases by 200 modules/week up to a goal of 1000 modules/week by 

the year end. A report on successful UL qualification of the product appears in the Task 5 

Section. 

Milestone Description 

m-2.4.1b Complete thorough review of laser scribing process including parameter 

flexibility, capital costs, and cycle time. 

This milestone has been successfully completed. Detailed description of the work during the 

2nd quarter of 2000 is listed below, followed by the summary of the accomplishments. 
26

Laser Scribing 

Review of the laser-scribing process 

Cell interconnection by the use of laser scribing is a new task to Phase II. The stated 

objective is to implement an improved scribing technique and design associated equipment, 

so as to result in low-cost scribing by increasing the throughput by a factor of two, and 

reducing the downtime by a factor or three and reducing capital requirements by at least a 

factor of two. 

With the imminent scale-up of PV module manufacturing throughput at First Solar, to 

anticipated 20 MW within a year and 100 MW within 2 to 3 years, the R&D and Engineering 

teams have been facing a major challenge of putting in place appropriate laser facilities to 

handle this task. Up until recently a Q-switched, lamp-pumped, frequency-doubled, 

neodymium YAG laser for the scribing, which emits green light at 532 nm. Lamp-pumped 

lasers operate at a low pulse frequency of up to about 20 kHz and at a long pulse width of up 

to several hundred nanoseconds (ns) which limit their scribing rate to about 20 cm/s, same as 

the maximum rate disclosed in several patents [1, 2] and published articles [3, 4]. With the 

existing systems, a continuously operating single laser system at a 100% yield would 

theoretically support a throughput of only 30,000 modules per year, equivalent to 1.5 

MW/year. In addition, the frequency-doubled, green-light emitting lasers have a limited life 

of only about 700 hours, imposed by the frequency-doubling crystal, which along with their 

higher initial cost makes their use for high-rate production prohibitive. It is to be pointed out 

that while prior art identifies important desirable characteristics of the lasers and a number of 

preferred methods of operation, there is no recipe given that would teach how to increase the 

production rate significantly and at the same time to reduce the system and operational costs. 

In order to eliminate this production bottleneck, the main objective of the effort at First Solar 

is to increase the rate of laser scribing per single laser by a factor of greater than two by 

taking advantage of newly discovered phenomena, and of ongoing improvements in 

instrumentation, components and methods. As it turned out, an increase by a factor of ten 

appears feasible. 

The second objective is to develop means for predicting laser specifications and system 

operating conditions required for increasing the rates of laser scribing. 

The third objective is to identify the most suitable lasers from the standpoint of performance, 

energy efficiency, cost, longevity and serviceability. 

The fourth objective is to identify a laser system and method capable of performing all three 

types of scribe lines needed (S1, S2, and S3) at high speed, good depth and shape control, 

reproducibility and reliability. 

The fifth objective is to achieve all three scribes without significant impairment of the 

transparent conducting oxide (TCO) electrode and without creating electrical shunts and 

shorts along the scribe lines. 
27

The sixth objective is to provide a suitable means of scanning the laser beam at required 

speeds to achieve the required scribing rates. This is the most important objective for 

developing the production system in the PVMaT program. 

Considerable effort has been expended toward these goals during the period of July 1998 to 

February 1999 under Solar Cells and First Solar funding, which is summarized by the way of 

introduction. As the first step toward achieving said objectives, modeling of the laserscribing process was performed to facilitate the prediction of the laser scribing parameters. 

In this modeling the laser scribing speed and the laser wavelength were the only independent 

parameters. Equations have been identified or developed for predicting laser parameters or 

process conditions, the most important of which were average laser power, peak pulse power, 

and pulse frequency. Key input parameters include laser pulse width, pulse energy, scribed 

area and the material being scribed. 

Next, a new laser, heretofore not reported as being used for laser-scribing of solar cells, has 

been identified as potentially suitable for rapid laser scribing of CdTe-based solar cells of up 

to 300 cm/s. It is a diode-pumped, Q-switched, neodymium-doped, yttrium vanadate laser, 

radiating at a near-IR wavelength of 1064 nm, operating at a pulse frequency in the range of 

5 to 100 kHz, and with pulse width ranging from 8 to 20 ns. Single-laser units of up to 10 W 

are now commercially available, which can be combined in a single beam in the multiples of 

10 W. Its cost is about 20% less than that of a frequency-doubled laser and its life 

expectancy is 10,000 hours. It is to be noted that the same near-IR laser delivers 

approximately twice the average power than the frequency-doubled laser. In addition, 

replacement of the photodiode assembly at the end of life is a simple task. In some models 

the replacement requires only about 15 minutes at a replacement cost of only about 20% of 

the cost of the laser. 

At First Solar, experimentation with the vanadate laser began in early 1999 and soon after it 

was followed by the design of the galvanometer-driven laser scanning system for module 

production. A description of this effort follows. 

Laser scribing experiments – establishing process latitude (parameter flexibility) 

A major task was to establish whether the near-IR laser could make scribe lines in the solarcell layers as good as the green laser, in view of the fact that the reported optical absorption 

of the near-IR radiation by CdTe is much less than that of the green light at low light power. 

The performance of the near-IR yttrium vanadate laser was therefore evaluated to determine 

its limits of practical performance. Very effective laser scribing has been demonstrated by 

First Solar for all three scribe lines both from the film side and the glass side. Scribing from 

the glass side was found to be several times more energy efficient and, therefore faster, than 

scribing from the film side, in agreement with previous reports [3, 4] for the 1064 nm 

radiation. 

In addition, scribing of the S2 and S3 lines from the glass side using the high-pulse frequency 

at low pulse width, the near-IR yttrium vanadate laser has been found to be more 

reproducible and better quality, than with the frequency-doubled, green-light laser. 

In order to take advantage of the rapid scribing capability of the Nd:yttrium vanadate laser, 

the “flying optics” normally used on X-Y laser-scribing tables, with a maximum linear speed 
28

of 30 cm/s have been substituted by a stationary galvanometer-driven scanning mirror, 

capable of order-of-magnitude increase in the scanning rate of the laser beam. Development 

of a module-scribing process using the galvanometer now in progress since the summer of 

1999 has become a part of the PVMaT project in the eighth quarter. A summary of the 

activities toward establishing process latitude is given below. 

3⁄4 A series of bench-top tests was done with a Spectra Physics ND:YVO4, 20W, Model 

T80-YHP40-106QW laser. The beam was traversed with a General Scanning Z-axis 

Galvanometer over samples of CdS/CdTe cells on 4-inch square substrates. The 

beam was focused to provide minimum kerf width of approximately 50 microns, at a 

given speed. No attempt was made to measure theoretical spot size. 

3⁄4 These tests are being performed to establish the feasibility of scribing the solar cell 

layers from the glass side. This involves the laser radiation passing through the glass 

substrate undisturbed, and then selectively removing semiconductor and/or metal 

coatings based on energy density. 

3⁄4 Earlier tests have shown a window of energy needed to create each scribe. An 

example of laser-scribing parameters investigated to determine process latitude is 

given in Table 1. 

3⁄4 Data of this type are used for the determination of window of conditions of average 

laser power, pulse repetition rate and pulse energy for obtaining the desired scribe. 

As shown in Table 2, these three conditions are interrelated. 

Construction of the laser-scribing equipment 

During the seventh quarter, the effort was focused on building of the laser-scribing 

equipment in Scottsdale, AZ. At the same time, some test runs to determine the cause of 

what appeared to be erratic pulses from the laser. Scribing was being done to further 

determine the parameters for optimum ablation. It was noticed that some portion of the scribe 

lines appeared to have areas where the laser was turning off. These scribes were done at 2000 

to 3000 mm/second at repetition rates of 70 to 80 kHz. Subsequent tests showed this pattern 

changing with different 10 cm x 10 cm panels. Tests were then made on panels from the new 

100 kW/year deposition system, called GDS, and the pattern disappeared. When analyzed at 

the First Solar Technology Center in Perrysburg, these samples did not show any significant 

film thickness variation. However, here was small difference in grain size. 

Delivery and installation of the rapid production laser system to Cedar Park

Through the month of June 2000 the laser system from Arizona Manufacturing was shipped 

to Cedar Park and installed. This system employs a galvanometer-driven, laser-scanning 

system for rapid laser scribing. The wiring was connected, air supply and nitrogen supply 

provided (the latter for the lenses) and communications connected to the local network. 

Currently the software is being completed to control the overall system. The system consists 

of six major parts: (1) the load station, (2) the scribe station, (3) the unload station, (4) the 

laser with galvanometer-driven mirrors, (5) the process control (PCs), and (6) the power 

station. Figures 12 and 13 show photographs taken from the entrance and exit sides of the 

system. 
29

Table 1. Example of laser-scribing process parameters for determination of process l

INPUT wavelength (nm) Rep. Rate (khz) Ave. Power (watts) Pulse Duration (nsec) Dot Dia. (microns) Line Speed (mm/sec) Pulse stability (%) OUTPUT Resistance (ohms) Dot area (cm2) Dot Spacin

1331-05 60 12.4 60 75 3000 900 4.E-05 50 1332-07 60 12.4 60 75 3000 1000 4.E-05 50 1331-03 60 13.4 60 75 3000 1200 4.E-05 50 1331-04 60 13.4 60 75 3000 3000 4.E-05 50 1331-02 60 14.5 60 75 3000 500 4.E-05 50 1331-01 60 15.3 60 75 3000 1200 4.E-05 50 1333-01 70 8.0 69 75 3000 250 4.E-05 43 1333-02 70 9.2 69 75 3000 220 4.E-05 43 1331-12 70 10.0 69 75 3000 40 4.E-05 43 1331-14 70 10.0 69 75 3000 35 4.E-05 43 1332-02 70 10.0 69 75 3000 35 4.E-05 43 1333-03 70 10.0 69 75 3000 40 4.E-05 43 1333-04 70 11.3 69 75 3000 190 4.E-05 43 1333-05 70 12.5 69 75 3000 120 4.E-05 43 1333-06 70 12.5 69 75 3000 800 4.E-05 43 1331-13 80 10.4 75 75 3000 30 4.E-05 38 
30

Table 2. A chart showing the process latitude of laser-scribing parameters for 

scribe-2, including average diode current, average laser power at 70 kHz, pulse 

rate, and pulse energy. 

Rep Rate (Khz)

40 50 60 70 80 90 100

28 4.8

29

1408

E=98

1404

E=83

1402

E=73

poor

1399

E=64

5.8

30

1407

E=113

1403

E=99

1401

E=86

poor

1398

E=77

6.9

31

E=200

poor

1332-08

E=133

good S2

1331-01

E=114

good S2

1406

E=101

1397

E=88

poor

8

32

1332-10

E=176

poor

1331-08

E=152

fair

1331-02

E=131

good S2

1405

E=116

1396

E=102 9.2

33

E=250

poor

1331-09

E=167

poor

1331-14

E=143

fair

1331-13

E=130

good S2

1395

E=113 10

34

1333-04

E=161

poor

1400

E=128 11.3

35

1333-06

E=179

poor

1410

E=156 12.5

36 13.5

37 14.7

38 15.5

39

E=255

poor 16

Average Power (diode current)

Average Power (watts) at 70 Khz
31

Figure 12. Photograph of First Solar rapid laser-scribing system, showing 

the loading station, the process control station the scribing station 

(enclosed in cabinet), and the power-supply station (to the rear) 

Figure 13. The laser scribing system - the unloading station and system side view 
32

Shortly after the installation, first glass plates have been successfully moved through the laser 

scribe station, which is in the center of three stations. After minor adjustments, moving of the 

glass appears to be working well. 

The immediate goal was to finish up the movement of the glass and also to integrate the laser 

into the system, making it ready to test laser scribing of the modules. Accordingly, during 

July the following tasks have been completed: 

3⁄4 The mechanical, optical, and electrical alignment of the entire optical train 

3⁄4 Installation of sufficient software to move the glass panel through the machine in 

proper sequence. 

3⁄4 Installation of sufficient software to scribe the glass accurately and rapidly. The first 

few tests show that Scribe 1 can be done easily at ~ 1600 mm/s, scribe 2 at ~2500 

mm/s, and Scribe 3 at ~ 3300 mm/s compared with ~300 mm/s for the existing 

scribing system now in use. 

3⁄4 Installation of sufficient software to control the system with both “step and cut” 

scribing and “continuous motion” scribing. The first timing demonstrations at a 

scribing speed of ~2500 mm/s resulted in the scribing portion of the machine cycle, 

yielded times for ~32 seconds for the “continuous motion” method and ~79 seconds 

for the “step and cut” method per panel. 

3⁄4 Completed some accuracy tests with excellent results. Measuring over 90 scribes 

with 1-cm spacing, the tests show the system accuracy in the range of ~100 microns 

cumulative error, or ~ 1 micron per scribe. In comparison with scribing done on the 

present, production ILM system, the same measurement indicated ~ 1490 microns 

over 90 cm. 

It is expected that within the next few weeks the process parameters will be established for 

the laser and machine variables, reduce process time, and interface and maintenance software 

capabilities added. This system will be used for Scribe-1, in which the semiconductor layers 

and TCO are patterned. 

At the First Solar Laser Group in Scottsdale, AZ, the second laser scribing system is nearing 

completion, which will be used for Scribe-2 and –3, in which the semiconductor layers and 

the metal electrode layer are patterned, respectively. For all three scribes, scribing is done 

from the glass side, which is several times faster than scribing from the film side. The 

scribing procedure will be described in future reports. Wiring of the second system has been 

completed and checked and mechanical connections finalized. Upon completion, the system 

will also be moved to the Cedar Park production plant in Perrysburg, OH. Additional work 

was conducted and documented under section 6.1.1 Task 7 on page 46. 

Summary of Milestone m-2.4.1b accomplishments 

Description of the laser-scribing process 

3⁄4 A panel is loaded into the Load Station either by an operator or automated 

equipment. This loading equipment is in-house but has not been integrated as of this 

date. 

3⁄4 The panel is operator inspected for debris or smudges and cleaned as needed. 
33

3⁄4 The operator presses the start button and the panel moves to a vertical position and 

indexes to the bar code read position. 

3⁄4 The panel then moves into the Scribe Station and is automatically transferred to the 

scribe carriage. 

3⁄4 The scribe carriage moves into the scribe location and fiducials are read and scribe 

position errors compensated for. 

3⁄4 At this point the vacuum/air pucks are holding the panel at the correct focal point and 

3 laser distance gauges have verified the focal plane. 

3⁄4 The panel is then scribed, from the glass side, with 117 scribes as the carriage moves 

at a constant velocity. 

3⁄4 An alternative scribe process for scribes 2 and 3 is to locate scribe 1 with the vision 

system, calculate position error, compensate for error, add next scribe, locate next 

scribe 1 and repeat. This greatly slows down the process but may need to be done 

until the ILM can place scribes repeatedly in the same location. It may be done on 

each panel or on a sample basis until confidence is gained. 

3⁄4 After the last scribe has been completed the panel is transferred automatically from 

the scribe carriage to the exit rollers. 

3⁄4 The panel exits the machine and is placed in the Unload Station. 

3⁄4 The panel is then removed by the operator or by automated equipment (in house). 

Parameter flexibility 

Initial bench tests described above show the windows for the scribes. Determination of the 

parametrics on the actual installed production equipment is forthcoming. 

Capital costs 

The first two systems look like they will be about $320,000 each plus design labor. 

Additional systems are estimated to cost $300,000 plus $160,000 labor. For comparison, ILT 

had given us a bid of $720,000 for a four-head system much like the current ILM system. 

Cycle time 

The systems were designed to meet a one-minute per 120 cm x 60 cm panel cycle time 

allowing 37 seconds for a scribe. The present speed is two minutes per panel, as we have not 

yet started to optimize the speed on various functions. If we are required to locate each scribe 

as described above the time goes to 4 to 5 minutes per panel. This is viewed as temporary but 

does add flexibility to the system. 

Milestone Description 

m-2.4.2 Complete the Phase II portion of the effort under Task 4. 

This milestone has been accomplished. 
34

5.1.2. Task 5 Milestones--- Product Readiness 

m-2.1.2 Initiate contact with the module testing laboratory and complete 

preliminary module design review 

(Task 5) 

m-2.2.2 Complete preliminary testing of First Solar’s modified modules (Task 5) 

m-2.2.3 Establish qualification testing schedule. (Task 5) 

m-2.3.2 Initiate qualification testing on First Solar’s modified module (Task 5) 

m-2.4.3 Complete qualification testing on First Solar’s modified module 

UL1703 

(Task 5) 

m-2.4.4 Complete the Phase II portion of the effort under Task 5. (Task 5) 

Milestone Description 

m-2.1.2 Initiate contact with the module testing laboratory and complete preliminary 

module design review 

This milestone was accomplished. Periodic communication with UL was maintained both 

for contact termination and module finalization (Tasks 4 and 5) throughout Phase II. 

Preliminary Module Testing Report and Testing Schedule 

In Phase I of this work, testing by the Arizona State University Photovoltaic Testing 

Laboratory according to IEEE 1262 protocol resulted in module failure for the damp-heat test 

(sequence “C”) and the heat-humidity-freeze test (sequence “B”). Based on these results, a 

plan was developed to identify and correct module design and lamination process issues to 

allow passage of both IEEE 1262 and UL 1703 qualification tests during this phase of the 

work. This was not only an important objective for PVMaT, but the PV market demands 

these certifications and First Solar must achieve them to be commercially successful in the 

short term. 

Specifically, the plan elements to achieve certification were to: 

3⁄4 Evaluate increased edge deletion area as a way to prevent or delay moisture ingress 

3⁄4 Test various edge potting concepts to provide another barrier at the 

semiconductor/encapsulant interface 

3⁄4 Continue testing of the liquid resin alternative to EVA 

3⁄4 Test insulated glass encapsulation as an alternative to a full contact interlayer 

3⁄4 Verify the thermal uniformity of the autoclave laminating device and confirm appropriate 

pressure and temperature cycles 

3⁄4 Review the First Solar lamination process with STR (the EVA supplier) 

3⁄4 Test alternative edge preparation techniques 

3⁄4 Investigate different potting techniques 

3⁄4 Develop more rigid cover glass flatness requirements with the cover glass vendor 

Solar Finishing Line Concept Design Review 

The design review was already discussed in Task 4 in reference to the solar finishing line. 

At the design review meeting it was also recognized that the issue of the module lamination 

had not yet been settled. Accordingly, work was to continue at First Solar in Toledo on the 
35

cold-cure polyester lamination that had shown promising results to date, and in parallel a new 

effort was to begin at Product Search. Accordingly, evaluation of other alternatives with two 

other resin manufacturers was initiated and was well underway by the end of May. 

Milestone Description 

m-2.2.2 Complete preliminary testing of First Solar modified modules 

Prior to completing preliminary testing of modified modules both the contact termination 

(see Task 4) and module lamination had to be firmly established. The work on module 

lamination is summarize next. By the end of the sixth quarter the milestone was completed. 

Module Lamination 

In response to the failed qualification tests of the modules – from the beginning of Phase II 

several alternative module finalization schemes have been evaluated toward achieving the 

Phase II qualification objective. In addition to work on the EVA pressure-lamination 

process, several possible solutions have been investigated simultaneously or in close 

sequence starting in June, 1999. 

Problems and improvements in the EVA pressure-lamination system 

Toward the end of Phase I, two failure modes have been identified. The first one is 

migration of moisture from the edges of the module along the interface of the front substrate 

glass and of the EVA laminate to the metal and semiconductor layers, causing their corrosion 

and failure. Several solutions to this problem have been attempted, including work on three 

different lamination concepts. These attempts are described in detail in the November 1999 

Deliverable 2.2.2. The following is a summary of this work. 

The migration of moisture along the edges is facilitated by a 1-cm wide, “edge-delete” region 

along the periphery of the coated substrate, which is actually a small step in the glass, formed 

by grit ablation of the deposited layers. Another cause of failure was found to be the 

deionized water used to wipe off the dust following the edge deletion. By changing to 

isopropanol, the modules survived the test, thereby removing the main cause of failures. 

In an attempt to find another solution to the moisture-ingress failure mode, development of 

an edge-potting technique was attempted, similar to that used in the crystalline silicon 

modules. The modules were failing the damp-heat test. The likely reason that edge potting 

works for the crystalline silicon and not for thin-film modules is that with silicon modules 

use two layers of EVA, whereas the thin film modules use only one layer. 

A secondary mode of failure has to do with incomplete adhesion of the back substrate to the 

front substrate, which is exacerbated through thermal cycling or thermal stress. Sometimes 

there would be just a wholesale mechanical failure where the module will delaminate or 

delaminate in places. Then the electrical contacts get torn off and the module quickly fails. 

Several test failures in pressure-laminated modules using EVA have been traced recently to 

the autoclave, the racks on which the modules rest, the means of applying vacuum between 

the plates, and the non-uniform heating of the modules. A painstaking review of these issues 
36

was made, followed by modifications in the laminating system, as described in the monthly 

reports. Substantial improvements in the module performance and durability have been 

achieved, as well as increased production capacity. Eventually with continued improvements 

the EVA pressure lamination process proved to be sufficiently reliable to be adopted for 

submission of the modules for UL qualification and for production. 

Concurrently with the improvements on the pressure lamination process, three alternative 

lamination methods were under development, as summarized next. 

The cold-cure liquid polyester resin laminate system 

Work on the cold-cure liquid polyester resin laminate system had been initiated during Phase 

I. The process involves placing a cover glass over the substrate plate bearing the solar cell 

layers, placing a double-sided tape on all four sides, leaving a release liner in place on the 

fourth side, dispensing the resin in it, removing the liner and closing the glass envelope. 

Three modules were made with each of three types of cold-cure liquid polyester resin 

supplied by Zircon, Inc. They were subjected to an in-house environmental testing. In the 

best cases the modules passed the severe damp-heat test. All three gave indications of 

exceeding the high temperature/high humidity requirements of the IEEE qualification testing. 

The advantages to this system, include process simplicity, low equipment cost, one half the 

material cost, compared with the EVA process, and the use of flat, annealed back glass. The 

process also achieved two goals of Phase II, namely, a 25 percent materials cost reduction, 

and a throughput of 60 modules per hour. Furthermore, there is no degradation in conversion 

efficiency upon lamination, compared with a relative loss of about 5% in the EVA pressure 

lamination process. The main disadvantage of the cold-cure process is that it was designed to 

cure in 24 hours. This lengthy cure would impose a requirement of providing enough space 

to carry a day’s inventory and for allowing the product to cure before it is shipped. 

 

The insulated glass concept for module finalization 

Insulated glass technology, originally developed by Pittsburgh Plate Glass, is a concept 

widely used in commercial building and residential home windows as a means for thermal 

insulation. A company named Glass Equipment Development uses an improved process 

called glass-intercept system, capable of processing 16,000 square feet of glass in one 8-hour 

shift. It is a well-proven system, having been put through a very extensive and rigorous 

environmental testing. Golden Photon used this concept in its PV module finalization; their 

modules passed both the IEEE 1262 and UL 1703 testing. 

Arrangements were made for finalization of three First Solar prototype PV modules to be 

done by this process. All three modules finalized by the insulated-glass process passed the 

damp-heat test readily, showing relative decreases in efficiency of 0.1, 4.8 and 9.4%, 

respectively, thus indicating a viable process for a durable product. 

The advantages of the insulated glass product are that it is a proven concept and that the cost 

of finalization is lower by factors of two and four compared with the polyester resin system, 

and the EVA system, respectively. 
37

Submissions of product specifications to UL 

Product Search submitted the product specifications in September, and received some 

application forms from UL. Then a preliminary module mockup was completed by the end 

of September and sent to UL for engineering evaluation by October 1. 

Milestone Description 

m-2.2.3 Establish qualification testing schedule. 

The qualification testing schedule was established in January, 2000 by submitting modules to 

UL testing, thereby completing the milestone. 

Modification of the manifold on the twenty-module lamination rack 

Two changes were made to eliminate the bowing of the modules laminated on the 20-module 

rack. The spacer, made a silicone caulk, was replaced by accurately machined Teflon spacer, 

that had a lower coefficient of friction, allowing the module could slide on it. Secondly, 

center supports have been installed to protect the module from sagging in the middle. Initial 

tests with this modified rack have shown that the bowing problem has been resolved.

A third change consisted of modifying the manifold on the 20-module rack for the autoclave. 

It was found that using these two manifolds was that if we had a module that fractured during 

the evacuation cycle, there was a risk of losing vacuum along with all ten modules being 

laminated. The modification consisted of providing ten pairs of manifolds, each connected to 

a pair of modules. That way, if a module cracked, the only other module at risk, namely, its 

twin. This change resulted in an improved yield and reliability of the process. The change in 

the manifold design increased the product yield to 90 percent or better through the autoclave 

cycle. This improvement was specifically with respect to cosmetic failures, such as bubbles 

and voids that would occur in the EVA. 

Submission of PV modules made with the cord plate to UL testing 

Efforts to resolve the environmental problems with the cord plate continued into midJanuary. Finally, by January 17 the results of internal testing with the humidity-freeze 

cycles, the environmental chamber, hi-pot testing, current-leakage tests were positive. 

Internal statistical evaluation indicated that the new cord-plate design had a good chance of 

passing the UL test and that the company had a good, viable product. Hence, the modules 

incorporating the Cord Plate have been submitted for UL testing in January. 

The major issue then was to get through the UL testing. At this point there was some 

uncertainty about the material currently used for the cord plate. The intention was to use 

material called Valox that was used for the top hat. The Valox material was specified 

because of its dielectric strength and intended use for the top hat design which would have 

been inside a J box mounted to the module surface. The Lexan # 950 is also a good dielectric 

material but, in addition, it is also resistant to heat and ultraviolet light. This is required 

because the cord plate is not intended to be utilized within a J-box enclosure. However, a 
38

switch was made to Lexan, or a second alternate material. This switch was made in 

anticipation of better performance through the destructive testing to which UL subjects it. 

It was expected that there would be some detail design changes in the cord plate, to enhance 

the manufacturability, the moldability, and performance of the cord plate. If the product 

were to pass the UL test a certain change would be that of going to injection-molded cord 

plates instead of the NC-machined parts used in these tests. 

Manufacturing throughput and costs 

Internal evaluation of the progress on the cord-plate termination process to date has made it 

possible to make projections of the manufacturing throughput and costs. Because of the 

elimination of potting, which was a time-consuming process, the projected production rate is 

one finished module per minute, which is about a ten-fold increase over the present rate. 

With respect to materials costs, First Solar achieved or will achieve the goal, of under $20 

per unit, from the present $27 per unit. The materials include all items in the module except 

the substrate plate containing all of the deposited layers up through the back metal film 

electrode. It was also estimated that the direct labor cost will drop from the existing $20 to 

below $5 and conceivably down to $3.75 to $4 per unit. More accurate figures about the 

costs can be projected following the UL tests and listing. 

Following the UL listing, preparations will be made for a new round of IEEE tests in view of 

fact that the module failed in two of the four tests in Phase I. 

The urgency of obtaining the UL listing first is that the customers for First Solar product are 

demanding it, prior to making any substantial commitments for its purchase. In time, the 

IEEE approval will also be important for the installation, in obtaining building and 

construction permits. That is the reason for placing emphasis on UL listing at this time. 

Milestone Description

m-2.3.2 Initiate qualification testing on First Solar’s modified module.

This milestone was accomplished on schedule. 

UL qualification testing of the Cord-Plate PV module

By the end of March tests to date have indicated passing with the exception of one minor 

change that was required for power lead strain relief. As shown in Figure 7, additional strain 

relief brackets were subsequently added external to the Cord Plate module (termination 

connection) to satisfy UL requirements for two levels of strain relief protection. Final 

documentation of all related components is being prepared to satisfy documentation and 

routing paper work that the UL Field Engineer will need to see when he visits the First Solar 

plant. 
39

Additional in-house testing and improvement of the Cord-Plate contact termination

The modules that are passing the UL tests utilized machined polymer Cord-Plate fixtures. 

When it became apparent that the concept was promising, equipment for injection molding of 

the fixtures was purchased and sufficient quantity of the fixtures for additional in-house 

testing was produced. The molded parts showed slight irregularities and bending on the 

bottom side. In order to obtain a flat bottom, the parts were ground on a belt sander. 

Modules made with the ground parts showed an 80-percent failure rate in the high-pot 

testing. Apparently the microscopic grooves formed by the grinding contributed to moisture 

ingress and test failure. 

The next attempt to produce a flat, smooth bottom surface was to place the Cord Plate 

fixtures on a flat surface heated to 150 o

C. This treatment produced the desired 

characteristics and resulted in a substantial improvement in the high-pot testing. 

Milestone Description

m-2.4.3 Complete qualification testing on First Solar’s modified module UL1703 

This milestone was successfully completed on schedule.

Completion of UL qualification testing of the Cord-Plate PV module

Underwriter Laboratories testing was nearing completion in June. First Solar completed UL 

testing in July and are now certified against UL 1703. 

Also in July, First Solar began preparing samples to submit to PTL for IEEE and IEC 

validation testing. A purchase order was placed with PTL for the testing in July. 

Mr. Tim Pruder, site inspector for Underwriter Laboratories (UL) from Novi, Michigan, 

arrived during July for inspection to the First Solar Cedar Park manufacturing plant. He 

inspected the documentation and materials listed by First Solar and verified the sources. He 

found no problems. The First Solar 60 cm x 120 cm PV module based on cadmium telluride 

is now a “recognized component,” approved by UL to be installed in “listed” mounting 

systems. A copy of the letter from UL in reference to completion of the Initial Production 

Inspection appears in Attachment A. 

On July 10 Underwriter Laboratories issued a Report on COMPONENT – 

PHOTOVOLTAIC MODULES TO First Solar, LLC, (File E205874, Project 99NK42717). 

In the Conclusions of this report it is stated that the products are judged to be eligible for 

Component Recognition and Follow up Service. This 31 page report and letter will be made 

a part of the Deliverable D-2.4.5, entitled “Testing report summary and letters of certification 

for First Solar modified module under UL1703 (Task 5).

Milestone Description

m-2.4.4 Complete the Phase II portion of the effort under Task 5. 
40

With the successful UL qualification of the First Solar modified module and the building and 

installation of the equipment for producing it, this milestone has been successfully 

accomplished. Additional work on encapsulation, using alternative concepts to eliminate 

back glass cover was undertaken. Description of this work follows. 

New module encapsulation projects 

Generation-3 (GEN-3) module encapsulation 

In March, 2000 a new encapsulation process came under development in which the back 

glass cover plate is substituted by a combination of a polymer layer as a dielectric and 

aluminum foil as a moisture barrier, affixed to the front PV plate with adhesives. A 

confidential full report on this ongoing project is included in the March 2000 report. The 

main purpose of this project is to reduce the weight, production rate and cost of the PV 

modules. 

Several variants of this concept have been fabricated and are undergoing testing. Tests have 

continued on the concept of using a thin aluminum foil and polymer film laminate at the back 

surface of semiconductor to seal panels. Problems of differential expansion in tests have 

caused wrinkles in all films that have had an aluminum foil component in the laminate on the 

full size modules. All other versions of films with aluminum foil have shown delamination 

wrinkles after just one full thermal cycle of 20 hours. A double-ply polyester with acrylic 

adhesive has not shown any delamination in damp heat-cycle tests. 

The latest combination tested was a polypropylene film with a vacuum-deposited aluminum 

coating. The sample was made up as a three-ply construction; it also failed the test. A low 

bond strength between polymer and the aluminum was suspect. This test is going to be 

repeated with just a single ply and making sure the aluminum coating is in contact with the 

adhesive to increase bond strength. 

The activities in April continued to focus on solving the wrinkling problems with metal 

(aluminum) backing materials and the associated differences in thermal expansion. 

The tests of thin vacuum-deposited aluminum / polypropylene films bonded to the panel on 

the aluminum side, seems not to be causing the previous wrinkle problem. This is done with 

a .002" thickness of a standard Acrylic adhesive system. The next tests was to involve a 

laminate that is built up of multiple layers and tested for moisture penetration. The test was to 

be conducted in the damp-heat testing system. 

In addition, samples of other materials backed by rubber/EPDM and rubber/vinyl were also 

undergoing tests. These materials would be relatively inexpensive if moisture migration is 

low enough not to degrade module performance. 

Systems for mounting / backing the module are also being reviewed. At this time the focus 

was mainly on extruded, vacuum-formed or blow-molded members. The issue was mainly 

of what type of encapsulation would result in the least material usage and still achieve the 

desired 20 year life. Materials being considered are: polycarbonate, vinyl, polypropylene and 

ultra-high molecular weight polyethylene (UHMV). 
41

In May, testing continued with plastic film / foil combinations and pressure sensitive 

adhesives for bond and lamination strength. All samples have failed so far from wrinkles in 

the aluminum layer. The two assumptions are that the strength of the bond is not sufficient to 

prevent the aluminum from delaminating. The other is the issue of the aluminum having 

over twice the temperature expansion of the glass. With the thermal expansion rates in mind 

we built samples with a thin galvanized steel backing and bonded it to the panel with a twopart urethane compound. This has survived the 200-hr thermal freeze cycle test with no signs 

of delamination. It has also shown no signs of delaminating the semiconductor layer. In 

addition a panel with a layer of polyester film and the urethane / steel was also tested; this 

resulted in a delamination of the urethane from the polyester. This test will be redone with a 

plastic film that has a better bond property to the urethane. This construction would allow 

for a wider range of intermediate bonding agents to the panel and backing metal surface. 

A Seaman’s panel that uses a composite backing film (ISOVOLTA type) was also run 

through the thermal cycle and, as expected, it did pass. These films use the intermediate 

layer of EVA to get a stronger bond, but are also only going against a glass surface and don’t 

need to worry about damaging the semiconductor. 

CoralPlast sheets were obtained and tested with the existing films. The results indicated that 

addition pretreating of the surface would be needed to get a better bond. Also long term 

effects of the plasticizer leaching form the material would be a concern for weakening the 

bond to the film or metal surface. 

Encapsulation Project 

A contact was made with TruSeal about the extruded hot melt. They have not as yet been 

able to extrude any 4” wide material at this time. They are confident that it can be 

accomplished; however, their lab equipment has not been able to make satisfactory product. 

They will be discussing the issue with their engineers to make equipment modifications to 

their extruder. They were advised about the urgency of the project and informed that First 

Solar would be willing to apply some “seed” money to expedite the project. They will 

contact us the first week of June 2000 with a timetable. In the meantime, several more minimodules have been put into damp heat testing using the hot melt. The main focus is the use 

of primers to improve the bonding between the sealant, glass and foil in an attempt to 

improve upon previous good test results. 

There were several samples in damp-heat testing. One test is a repeat of an earlier failed test 

with an aluminum foil and a hot-melt edge seal. The only change was to use a primer to 

improve the adhesion to the foil and glass. Another test was a repeat of a test that passed. 

This was a glass-to-glass lamination with an edge seal of hot melt. The only change was to 

use a primer to improve adhesion to the glass. Another test was using a PIB type extrusion, 

with a vinyl backer, from Plymouth. They will have the ability to extrude a 24-inch wide 

ribbon by the end of this year. This material is used for insulating electrical cables. Later test 

results were not acceptable. 

Work was continuing on the aluminum foil buckling problem. One option that is being 

tested is to bond the foil to a rigid backer, in this case a Coroplast panel. Coroplast is a 

polypropylene corrugated panel used as a cardboard substitute. It is expected to maintain the 
42

foil’s planar shape and prevent it from buckling. This panel will be laminated to the submodule with an adhesive and an edge sealant. (EVA as an adhesive with this contruction was 

not used because of difficulty bonding the EVA to the polypropylene, further work could be 

done) This joint will have to be sufficiently flexible to accommodate the thermal expansion 

differential between the glass and the panel, without losing the hermetic seal. Product Search 

is making up the panels and performing the thermal cycle tests. 

Alternatives are being explored to the aluminum foil for the vapor barrier. A film from 

Multi-Film Packaging, (double ply polyester with acrylic adhesive), was shipped at the end 

of March 2000 and testing began it in June. Some other films have been identified with low 

MVTRs from ISOVOLTA. They are sending samples for us to evaluate. As reported by the 

company, these films have been used with success in the production of several MW of PV 

panerls. They would be flexible enough to correct for thermal expansion and still maintain a 

good vapor barrier. 

In June 2000, TruSeal has obtained a four-inch die for their extruder. The company was 

attempting to make a .020” x 4” hot-melt ribbon on an aluminum foil backer with a paper 

liner. They were having difficulty rolling the ribbon into a coil because the paper/hot 

melt/foil stack-up would kink during the coiling process. A discussion of the problems 

ensued, including the foil wrinkling problem occurring during the thermal cycle test. Based 

upon that discussion First Solar requested to supply a hot-melt ribbon on a paper liner only. 

This material can be easily rolled into a coil. This ribbon will facilitate testing of minimodules and also full modules by laying up several strips of the ribbon. Delivery of the hotmelt ribbon was scheduled for July. 

After less than 300 hours, none of the damp-heat test mini-modules tested in March of 2000 

passed the test. (These included several polypropylene films with aluminum backing and 

well as Tedlar/aluminum/Tedlar provided by Isovolta) The best results were with the glassto-glass lamination with a performance drop of 11.04% (relative %). The worst results were 

with a VM tape with a performance drop of 54%. Most of the decrease was through a drop 

in Voc. 

Work on the back vapor barrier continued. Bonding of aluminum foil with different 

adhesives to a Coroplast corrugated panel is being tested. Another material on order is 

honeycomb polypropylene from Nida-Core. This panel has a polyester scrim thermally fused 

to the face, which should make it easier to bond. Product Search performed a thermal cycle 

test using 32 GA galvanized steel for the vapor barrier. Steel more closely matches the 

thermal expansion rate of glass than does aluminum. At First Solar a steel foil was tried in 

the past, but it also wrinkled. However, the thicker-gauge, galvanized steel has enough 

stiffness that it was able to resist wrinkling during the test. Although it is not as cost 

effective as aluminum foil (< $0.04/ft2 @ 1 mil), the cost is still reasonable (approx. < 

$0.30/ft2). It has a significant weight disadvantage of 4.36 lb vs. 0.11 lb for aluminum. It 

does have some advantages over foil. It is stiff enough to resist the impact tests. It is thick 

enough to resist the cut test. It may be strong enough to mount directly to it. 

The custom film from Flexicon was received. TruSeal performed a MVTR test and found it 

to be 9.2g/m2/d, which is higher than the hot-melt material. A mini-module will be put 

through the damp-heat test. Preparations were in progress for this testing, the Thermatron is 
43

in the process of being moved from the Westwood Plant in Toledo to the Technology Center 

in Perrysburg this month. The Thermatron will be operational in July. 

We received the ISOVOLTA film laminate. This is a lamination of Tedlar/aluminnum foil/ 

Tedlar/EVA. The laminate is relatively expensive ($0.80/ft2). Siemens uses this material for 

encapsulation with an EVA film. First Solar sent a Siemens module to Product Search for 

testing in the thermal cycle test. 

In the future First Solar is considering alternatives for encapsulation. One alternative is a 

barrier coating. This would be a metal oxide film such as tin oxide, aluminum oxide or zinc 

oxide that would use a low-temperature film-deposition process. First Solar personnel is 

exploring a low-temperature CVD process. Alan McMaster of First Solar is working with 

Tom McMahon at NREL, who is sputtering barrier layers. His first test used aluminum 

mirrors on a glass substrate. Initial test with aluminum oxide barriers showed corrosion in 

less than 24 hours in the damp heat (DH) test. He subsequently ran tests with thicker films ~ 

1μ. These film were resisting corrosion after four days. Based upon these results, barrier 

coatings were planned be deposited on dot cells. Testing was to begin in July. 

A “hot-melt” ribbon was delivered from TrueSeal early in July and encapsulation minimodules for the damp-heat testing was begun. The material is approximately 0.030” thick 

and 4” wide. It was supplied in a roll with a Kraft back-up paper. Several different types of 

mini-modules with different back coverings were laminated, using the hot-melt. Some of the 

mini-modules were covered with 0.003” aluminum foil, others with a glass cover plate, with 

just the hot-melt alone, and some others with no cover plate. Other coverings used were the 

Icosolar foil film lamination, Lexan, and the Flexicon film and also the 0.03”-thick 

galvanized steel; all of them were subjected to damp-heat testing. After two weeks of dampheat testing the PV performance was again measured. To date, the only one that is still 

performing to specifications is the mini-module with the glass cover plate on it, which had a 

performance drop of 5.5 %. All of the other combinations had more than 10 % performance 

loss after two weeks. The Thermotron, previously located in another building, at Westwood, 

was moved to the Technology Center, in Perrysburg, early in July and set up in the first two 

weeks in July. This move facilitated continuing the damp-heat testing at a more convenient 

location. 

Damp-heat testing will be continued with different combinations of encapsulating stack-ups. 

One that has not been tested up to this point is with alternative edge-delete treatments. 

Currently we are using sand-blasted edge delete, which leaves a pitted and micro-cracked 

glass surface, that has been shown to create problems with degradation, as reported recently, 

because of vapor ingress. 

Edge-deletion techniques are under consideration that are non-ablators, which will leave a 

pristine glass surface to which the encapsulating films will be bonded. It is felt that the 

existing edge deletion is the weak link in the encapsulating process. The CdS and CdTe 

semiconductor materials are relatively easy to remove. The underlying low-emissivity tin 

oxide layer is very hard and difficult to remove. One method to remove the tin oxide would 

be a pre-deletion, before the semiconductor layers are deposited. The tin oxide could be 

removed either chemically or electrolytically, leaving a smooth glass surface. 
44

Another edge deletion treatment under consideration is to isolate electrically the tin oxide 

film and coat it with another material that lends itself to bonding to tin oxide. To date no 

equipment suppliers have been able to provide an adequate system to deliver a chemical to 

the edge delete area without some contamination of the active area, or contamination during 

the rinsing process. Historically, when lamination to the tin oxide surface was attempted, 

the bond between it and the encapsulant was not good, which allowed water vapor to ingress 

to the semiconductor, causing a severe drop in performance. By treating the tin oxide with 

another chemical, so as to increase its surface energy, an improved bond to the encapsulant is 

expected. No further work was done to identify bond enhancement chemistries. 

5.1.3. Task 6 Milestones---Environmental, Safety and Health Programs 

m-2.1.3 Complete extensive review and survey of current ES&H programs. (Task 6) 

m-2.2.4 Develop plans for critical areas of ES&H improvement with the 

assistance of industry experts such as OSHA On-Site Consultation. 

(Task 6) 

m-2.3.3 Initiate EH&S improvement projects. (Task 6) 

m-2.4.5 Complete a comprehensive ES&H program assessment including 

prioritization of improvement areas; established measurement targets; 

and comparisons to industry historical levels. 

(Task 6) 

m-2.4.6 Complete the Phase II portion of the effort under Task 6 (Task 6) 

All of the above milestones have been accomplished, with the exception of the external and 

internal audits, which are now planned for Phase III Task 9. The reason for postponing the 

audits was because all EHS items had to be introduced to the new manufacturing plant 

The formation of the First Solar LLC partnership has added a major new responsibility on the 

EHS activity. It is to prepare environmentally sound and a safe working environment in the 

new Cedar Park manufacturing facility, and to provide training of new employees in accepted 

EHS practices. Since its formation, the number of employees has more than doubled. 

The goal of the EHS program is to conduct an extensive review of its current programs and 

address issues that need improvement. Altogether over thirty different activities have been 

conducted in the EHS program over the period of the Phase II project. Among these 

activities were: development and implementation of fifteen EHS-related plans and programs; 

obtaining permits concerning PV manufacture; generating reports to municipal and state 

agencies; cooperating with said agencies in conducting inspections; environmental sampling 

of R&D and production equipment and facilities for hazardous substances; installation and 

monitoring of EHS equipment; conducting safety inspections of all manufacturing 

equipment; periodic evaluation of employees for baseline cadmium; establishing first aid 

medical supply station; training of new employees on the EHS Handbook; conducting first 

aid training; establishing “Safety Council” meeting to address and assign controls to hazards 

in the start-up of the Cedar Park facility. The ultimate goal of the EHS program is to place 

First Solar in a leadership position relative to comparable businesses within and outside of 

the photovoltaic industry. Description of other accomplishments were included in Letter 

Deliverables D-2.4.6 and D-2.4.7. 
45

6. Phase III Task Overview 

Task 7. Manufacturing Line Improvements – Laser Scribing and Potting

First Solar, LLC shall continue to implement an improved scribing technique and design 

associated equipment initiated under Task 4 of Phase II. First Solar shall conduct a thorough 

review of the current process to locate potential industry processes and material handling 

solutions and establish parameters for integration of an improved throughput, labor, and 

equipment process improvements into the First Solar production line. First Solar shall 

formulate an improved process through adaptation of state-of-the-art techniques and 

automation. First Solar shall engage industrial experts and vendors such as the ARRI as 

needed in the development, design, and testing of a new scribing technique which is directly 

scalable to 60 modules per hour with potential of exceeding that capacity with nominal 

upgrades. First Solar shall complete off-line development of the individual scribing 

processes such as substrate registration, isolation measurement, and substrate conveyance. 

First Solar shall carry out the prototyping of material handling steps for the scribing process 

such as: handling large sheets of glass in and out of buffers; feeding glass in and out of the 

scribing table; and parts feeding. First Solar shall test a prototype scribing station to 

demonstrate the improvement elements and provide functional information for the highthroughput design. First Solar shall complete testing of the improved high-throughput 

scribing system, including process and material handling components, on its module 

production line. This task is expected to result in high-throughput, low-cost scribing by 

increasing throughput by a factor of four, reducing downtime by a factor of ten, and reducing 

equipment capital requirements by at least a factor of two. 

Task 8. Product Readiness

First Solar, LLC shall initiate and complete qualification testing of modules with a different 

design than that of the one certified in Tasks 2 and 5. Modifications may include one or 

more of the following depending on the market interest: 1) junction box instead of pigtails, 2) 

sizes other than 60 cm x 120 cm, 3) alternative voltage; 4) encapsulation materials or 

process, and 5) other product changes influenced by market demand. First Solar shall obtain 

IEEE 1262, IEC 1215, and UL 1703 certification for its modified module. Experts from the 

field including Underwriters Laboratory and the Photovoltaic Testing Laboratory at the 

Arizona State University shall be utilized to review the design of the module; conduct 

preliminary testing on certain design components; establish sample and schedule 

requirements; and complete the certification testing. The task is expected to improve 

acceptance and variety of First Solar’s product line in order to provide opportunity to 

penetrate market segments other than those that are served by its standard frameless, 60 cm x 

120 cm module. 

Note: Certification requirements were revised to include IEC 61646 and UL1703 only The 

IEEE 1262 was no longer in force at the time First Solar reached this task milestone. IEC 

1215 was originally intended for certification of Silicon modules. IEC 61646 was created 

specifically for “Thin-film terrestrial photovoltaic (PV) modules” 

Task 9. Environmental, Safety, and Health Programs

First Solar, LLC shall continue to refine and improve its Environmental, Safety, and Health, 

(ES&H) programs by beginning activities related to obtaining ISO 14000 (or equivalent) 
46

certification. First Solar shall initiate activities related to obtaining ISO 14000 by surveying 

and interviewing industry experts to assist First Solar. First Solar shall complete a 

comprehensive plan outlining the key milestones to obtaining ISO 14000 certification. First 

Solar shall assign and/or hire professional personnel to head up the implementation of the 

ISO 14000 project. First Solar shall begin the process of becoming certified under ISO 

14000 by beginning the documentation of First Solar’s current system within the ISO format 

and identifying areas of greatest need and highest priority. First Solar shall conduct a 

comprehensive review of the progress of their PVMaT Environmental, Safety, and Health 

programs and summarize the status of these efforts. This task is expected to result in a safe 

and healthy work place as well as an environmentally friendly manufacturing process and 

product. 

6.1.- Phase III Results for Task 7, 8, and 9 Milestones 

6.1.1. Task 7 Milestones---Manufacturing Line Improvements

m-3.1.1a Complete scribing improvement plan including methodology and 

resource allocation. 

(Task 7) 

m-3.2.1a Complete initial testing of scribing process improvements. (Task 7) 

m-3.3.1a Complete demonstration of improved scribing process. (Task 7) 

m-3.4.1a Complete demonstration of scribing process improvements. (Task 7) 

m-3.4.2 Complete the Phase III portion of the effort under Task 7. (Task 7) 

As described below, milestones m-3.1.1.a, m-3.2.1a, m-3.3.1a, m-3.4.1a, and m-3.4.2 have 

been completed. 

Laser Scribing 

Laser scribing of solar panels using thin film solar cells is used for cell interconnections i. 

The objective of Task 7 of Phase III of this project was to develop a system for scribing solar 

panels, measuring 120 cm x 60 cm, with a throughput of one per minute, at a reduced capital 

cost, improved reliability, improved scribe control and requiring the use of a single laser 

beam per each of three types of scribes. 

Traditional laser processing systems fall into two categories using either a fixed head with an 

X-Y table or a moving head. The first system’s major drawback is the speed limitation of 

large X-Y tables, which is in the range of 300 to 500 mm/sec. The second system suffers 

from sizeable vibration caused by the rapidly moving head. 

Improved Laser Scribing System 

The system selected for this work is capable of achieving a 60 cm long scribe line having a 

minimum theoretical spot size of 70 microns. Scribe-to-scribe location is easy to control. 

The scribing can reach speeds in excess of 3400 mm/sec requiring the use of pulsed lasers 

having a high rep-rate. A key benefit of this system is the ability to use a correction factor in 

the software, which allows cell mapping and correcting the focus for uneven surfaces. 
47

Laser-Scribing Methodology 

Traditionally, solar panels have been scribed from the coated side in which case scribing 

speed is limited to 300 to 400 mm/sec by the plume of vaporized material. The vapor plume 

absorbs and scatters the laser light and limits the power delivered to the scribe site. In order 

to achieve speeds in the range of 2000 mm/sec, scribing through the glass side of the solar 

panel, reported earlier [5], was pursued. 

Green-light (532 nm) lasers are typically used for solar cell scribing in order to match the 

wavelength to the optical absorption of the material. In this project we made use of nearinfrared lasers after determining that the CdTe absorption increases greatly with temperature 

for near-infrared wavelengths. 

Considering the structure of the solar panels, at the time of the first two scribes, it consists of 

a soda-lime glass plate superstrate that has been coated with layers of TCO, CdS, and CdTe. 

The TCO signifies transparent conductive oxide. Each layer has a lower energy gap than the 

layer before it. As lower band gap materials convert more of the laser power to heat needed 

to vaporize material, the outer layers, e.g. CdTe, can be removed at relatively lower laser 

power without damaging the inner layers, e.g., TCO. Scribe #1 removes all the layers on the 

glass; scribe #2 removes the CdS and CdTe without ablating the TCO. The back metal 

electrode is deposited after scribe #2 and scribe #3. Scribe #3 removes metal to isolate the 

back electrode. The metal is removed chiefly by the high-pressure CdTe vapor formed at its 

interface by the beam reflected by the metal. The scribing speeds for the three scribes are 

1500, 2000 and 2500 mm/sec, respectively. 

Figure 14. Sequential Function of the Scribing System 

Each of the three scribing system consists of a Load Station, Scribe Station and Unload 

Station. Figure 14 The first phase of the Load system accepts the panels via manual loading 

by the operator. The Scribe-1 Station receives the panel from the Load Station and indexes it 

into the scribe location. Any curvatures in the panel are measured for calculating a factor to 

maintain focus over the entire panel. For scribe-2 and -3 the systems operate similarly, 

except that the fiducial marks, scribed during scribe-one, are able to be read for position 

errors and software is capable of providing a correction factor for scribing. 

Loading glass into the Load Station and removing it from the Unload Station are done 

manually. During the second phase of the scribing project both the Load and Unload 

Stations will be automated. 
48

Improvements over Conventional Systems 

The improvements with the improved scribing system include: (1) Reduced capital cost - the 

cost of high-speed improved laser system is about 1/3 of the cost (parts and labor) of a 

conventional system, with four nozzles; (2) reduced and lower-cost maintenance, which 

reduces down-time by a factor of ten; (3) greatly enhanced location accuracy of subsequent 

scribes through the use of fiducials, coupled with automated correction for panel growth/ 

shrinkage caused by temperature variations as well as panel rotation; (4) substantially 

reduced kerf widths and scribe spacing, whereby the active area of the panel is increased; (5) 

IR lasers deliver about twice the power of frequency-doubled green lasers and have life 

expectancy of up to 10,000 hours, 14 times greater than green lasers, and lower cost; (6) 

increased production throughput by a factor of four. 

6.1.2. Task 8. Milestones---Product Readiness 

m-3.1.1b Complete encapsulation design review (Task 8) 

m-3.1.2 Initiate contact with module testing laboratory and complete 

preliminary module design review 

(Task 8) 

m-3.2.2 Complete preliminary testing of modules (Task 8) 

m-3.2.3 Establish qualification testing schedule (Task 8) 

m-3.3.2 Initiate qualification testing on First Solar’s modified module (Task 8) 

m-3.4.3 Complete qualification testing on First Solar’s modified module for 

IEEE 1262, IEC 1215, and UL 1703 

(Task 8) 

m-3.4.4 Complete the Phase III portion of the effort under Task 8 (Task 8) 

Milestone Description

m-3.1.1b Complete encapsulation design review (Task 8) 

Milestone m-3.1.1b has been completed. There have been several factors that contributed to 

the difficulty in passing module qualification testing. Figure 15 shows a cross section of a 

GEN 2 module. With the GEN 2 and earlier forms of encapsulation, the modes of failure 

have been moisture ingress to the semiconductor, moisture ingress to the bus bar and 

delamination. Moisture ingress is a result of insufficient bonding between the EVA and the 

glass, which allows moisture to penetrate along this interface. Moisture can also penetrate 

through the EVA that is exposed along the perimeter of the module. Moisture in contact with 

the semiconductor or bus bar causes degradation resulting in a loss in device performance. 

 EVA Semiconductor 

 Glass 

Figure 15. GEN 2 Encapsulation 
49

Delamination occurs as a result of stresses induced in the module during lamination. 

Typically, the lamination is done with an autoclave or vacuum process. Usually the glass 

superstrate, after going through the semiconductor deposition process, is no longer as flat as 

the cover glass. The superstrate-EVA-cover glass sandwich is put under a load of one 

atmosphere or more during lamination. The resulting module contains residual stresses. 

Stresses can also occur even if the superstrate remains flat after deposition. A small amount 

of glass is removed during edge delete process resulting in a step around the perimeter. In 

addition there is variation in the amount of glass removed that gives the edge delete border a 

wavy surface. Bus bars are also mounted to the superstrate surface. Any of these non-planar 

qualities can cause stress risers in the laminated product. EVA goes through a cross-linking 

cure during the lamination process and there is some shrinkage associated with this cure that 

can also add stress to the system. 

The module can delaminate during thermal cycling. Delamination typically begins in the 

deleted area and works its way into the body of the module. Sometimes there is internal 

delamination where the back contact has been pulled away from the semiconductor. Stresses 

can be high enough to break the cover glass or superstrate after a period of time. Stress in the 

glass can also be attributed to the positioning of the bus and terminal strips. Earlier potting 

methods have also allowed moisture ingress due to the failure of the potting material to 

withstand the damp heat test. Moisture absorbed in the potting material causes it to degrade 

and delaminate. 

There is limited potential for reducing costs associated with GEN 2 encapsulation and earlier 

designs. The cover glass, potting and EVA comprise over 80% of the module encapsulation 

material costs. Listed below are some of the desirable encapsulation material properties that 

have been identified: 

• Low MVTR < 1 g/m2/24 hours 

• Sealant material with low surface tension <50 dyne/cm 

• Vapor barrier material with high surface tension >500 dyne/cm 

• Low system cost < $0.625/ft2 ⇒ $0.10/watt 

• 20 year service life 

• Service Temperature -40C to 110C 

• CTE compatibility with glass 

• Good peel strength 10 ppi 

• Lap shear 25 PSI 

• Elongation >100% 

• Non flammable 

• Dielectric strength >2500 V/mil 

• UV resistance 20 yr life 

• Low cure time < 1 min. 

• Low cure temperature < 200C 

• Good green strength 

• Low VOC 

• Ease of automation (roll lamination, spray, gun, etc.) 

• Low capital equipment costs 

• Low labor costs 

• Chemically inert 
50

• Light weight < 1.6 lbs/ft2

• Low shrinkage < 2% 

• Pass UL 1703 and IEEE 1262 

Milestone Description 

m-3.1.2 Initiate contact with module testing laboratory and complete 

preliminary module design review 

(Task 8) 

This milestone is complete. Underwriters Laboratory Inc., Northbrook, IL, and Arizona 

State University Photovoltaic Testing Laboratory were selected as module testing 

laboratories. 

Milestone Description 

m-3.2.2 Complete preliminary testing of modules (Task 8) 

This milestone is complete. Typically, the damp heat qualification test is the most difficult to 

pass. Hence, this is where most of the effort has been focused. In order to improve 

performance, the edge-deleted area was increase to 14mm wide from the original 10mm. The 

increased path length was sufficient to lower the moisture ingress to the semiconductor. This 

substantially improved module performance through the damp heat test. 

Milestone Description 

m-3.2.3 Establish qualification testing schedule (Task 8) 

This milestone is complete (see m-3.3.2). 

Milestone Description 

m-3.3.2 Initiate qualification testing on First Solar modified module (Task 8) 

This milestone is complete. One of the tasks of Phase III was to initiate and complete 

qualification testing of PV modules with new design. First Solar was to obtain IEEE 1262, 

IEC 1215, and UL 1703 certification for its modified module. 

In November 2000, fifteen modules were submitted for testing to the Photovoltaic Testing 

Laboratory (PTL) at the Arizona State University in Scottsdale, AZ, in accordance with the 

IEEE standards. The modules did not pass the entire battery of tests because one of the 

modules fractured during the static load test and other modules failed various combinations 

of the damp heat test, humidity-freeze, and wet hi-pot tests. All modes of failure are 

traceable to the mounting structure, which rusted and fell off, as opposed to the encapsulated 

module itself. Modifications have been made and new modules will be resubmitted for 

testing. However, it is significant that First Solar’s PV modules themselves did successfully 

pass the most demanding set of tests. The PV modules passed the humidity freeze, damp heat 
51

and subsequent Hi-Pot tests. Performance decreased by 6% or less in power output through 

this sequence. This is a major accomplishment for a thin film module. 

Several in-house tests have been conducted in June to improve the understanding of First 

Solar’s product prior to resubmitting for IEEE certification. The tests revealed some 

concerns while undergoing damp heat trials. It was concluded that the IEEE resubmission 

should be postponed until better understanding is gained to resolve these issues. 

Milestone Description 

m-3.4.3 Complete qualification testing on First Solar modified module 

for IEC 61646, and UL 1703 

(Task 8) 

The UL 1703 qualification testing has been completed. At the start of Phase III First Solar 

PV modules received “recognition” from the Underwriter Laboratories, which allowed the 

modules to be used on listed mounting systems. 

During April 2001, and September 2002 modules were resubmitted to the Arizona Testing 

Laboratory with a c-channel and d-channel mounting system respectively. HF-10 and static 

load testing were successful and First Solar received authorization to use the UL Listed mark 

on its FS-50c and FS-50z and FS50d modules. These are complete modules with mounting 

attachments secured to the back side. The c, d, and z designations indicate the style of 

mounting with the c denoting aluminum c-channel rails, the d denoting aluminum d-channel 

and the z denoting aluminum z-bar rails. A photo of a module with the c-channel rails is 

shown in Figure 16 

A package was submitted to the California Energy Commission to qualify for the CEC buydown program, which was approved in August. First Solar was officially listed on their web 

site on 8 Aug. 2001. 
52

Figure 16. A photograph of the rear side of a module with the 

“c” channel mount rails 
53

The first array of UL-listed First Solar PV arrays is shown on the left front side of Figure 

16, consisting of two inclined rows of nine modules in each row. 

Figure 16. First Solar modules at ASU PTL. The first array of UL-listed 

First Solar PV modules with c-channel mounts is shown on the 

top front side of the photo 
54

Milestone Description 

m-3.4.4 Complete the Phase III portion of the effort under Task 8 (Task 8) 

This milestone has been completed. 

R&D Activities for Product Improvement 

During Phase III, the following R&D activities were conducted to facilitate product 

certification: 

1. Heat strengthening of glass to avoid breakage -- several modules installed in the First 

Solar test field experienced breakage of the glass. By using-heat strengthened submodules the in-field breakage rate has decreased from 11% to zero. Sample sizes were: 

45 non-heat-strengthened and 52 heat-strengthened. 

2. Through the use of a hot-melt pottant to extend the time to failure in the Hi-Pot test, the 

time to failure doubled from two to four minutes. Using the silicone RTV as the sole 

pottant, failure times are measured in days. This process is being qualified for use on the 

production line. 

3. After determining that a significant fraction of completed modules would fail a 

subsequent Hi-Pot test, a total of 4679 modules were retested. Modules failing the Hi-Pot 

test were reworked and retested. After the testing was completed 4480 modules were put 

back into the Finished Product inventory. The failure mode was caused by incomplete 

coverage by the RTV silicone sealant around the wires or solder cavity. Minor 

modifications have been made to the process by which the pottant is introduced to the 

cord plates. The changes allow a higher pressure buildup within the cavities in the cord 

plate while potting. This change has resulted in demonstration of longer survival times in 

test-to-failure Hi-Pot tests. 

4. The hole in the cover glass for the wire leads has been relocated from 10 cm to 25 cm off 

the edge of the glass; thereby lowering the tensile stresses in the laminated module an 

average of 500 PSI. 

5. Search for solutions to excessive electrical conductivity of soda-lime glass -- Recently it 

was found that the electrical conductivity of sodium-lime glass accounts for 

approximately 50% of the UL allowable limit. It has also been found, that the EVA 

encapsulant, currently in use, has poor electrical insulating properties when subjected to 

the "Damp Heat” accelerated life testing. Currently, alternate encapsulants to EVA are 

being screened; as well as potential solutions tested using EVA to improve electrical 

insulation during damp-heat testing. 

6. Control of the gel content of the EVA -- Statistical control of the minimum gel content of 

the EVA has been established. The process average is 83% and the control band is +/- 

6%. This measurement consists of sampling the EVA cross-linked in the coolest rack 

location of the oven. Each sample is measured in four locations the average and range is 

then plotted on the control chart. 
55

7. Problems with delamination of modules continued from time to time, even though 

reducing the curvature in the glass supplied by the vendor has helped. Variation of the 

lamination temperature has produced positive results; however, because of the small 

temperature changes used, it is not clear that temperature was involved in the 

improvement. 

8. Search for alternative pottants to for use with the cordplate process -- In the later stages 

of Phase III, problems with the reliability of the cordplate process were once again 

experienced during damp-heat testing. Three alternative pottant materials were evaluated 

in an effort to replace the existing 3M-jet-melt material. The preliminary results 

indicated that all three materials, bond very well to the cordplate material, Lexan; 

however, there appears to be a concern about the adhesion to the wire insulation jacket. 

9. Removal of air bubbles around lead wires by applying vacuum -- Another leading cause 

in lower yield was entraining bubbles along the lead wire. The old process to reduce 

bubbles was to put in a piece of rubber over the hole when applying vacuum, to keep the 

air from rushing in around the hole. However, the rubber leaked air. A complicating 

factor was that the lead wire passing through the hole was the thickest structure and it 

provided a path for the air to pass into the module. A partial solution was to apply 

vacuum to the hole itself by using a machined aluminum disk with a silicone rubber 

applied to the surface and plumbed up by using silicone tubing. The problem was 

thereby substantially reduced. The scrap rate for the process thereby decreased from 

about 15 % down to 8 %; which still indicated the need for other solutions. Hence, the 

aluminum vacuum disk was replaced with a silicone RTV vacuum cup. This new cup 

allows a better seal to the cover glass, resulting in better evacuation. As a result, the 

process average for voids has been reduced to zero. Consequently, the control chart for 

voids was discontinued and the incidence level was set to one void per run. 

10. Changes in the process of injecting the pottant at higher pressure to the cord plates, 

resulting in longer survival times in Hi-Pot tests. 

11. The automated Hi-Pot station has been brought on line to facilitate damp-heat testing of 

finished modules. 

 % Tolerance % Study 

Part to Part 128.0% 100% 

Total Gage 2.7% 2.1% 

Repeatability 0.8% 0.6% 

Reproducibility 2.6% 2.0% 

 

Distinct Categories 68 

Table 3: Hi-pot Gage R&R: Each panel was tested twice on both the manual and the auto 

Hi-pot tester. Since the panels do not retest the same, 10 dummy panels were 

used. The positive lead was connected to one end of the dummy and the other 

end of the dummy was placed in various locations in the liquid. 
56

Panel 1 40 Mohm Panel 6 50 Mohm

Panel 2 170 Mohm Panel 7 110 Mohm

Panel 3 40 Mohm Panel 8 50 Mohm

Panel 4 140 Mohm Panel 9 120 Mohm

Panel 5 200 Mohm Panel 10 40 Mohm

Table 4: Table 4 shows the resistors used in the dummy panels. 

12. Significant steps were made in June towards overcoming the potting issues. Currently, 

life cycle tests are in process to gain understanding and optimization of the potting 

process. These tests are on schedule, which calls for obtaining sufficient information by 

the end of August, 2001, for incorporating a better and more robust potting process that 

will meet all field extremes for the life of the product. It appears that the iterative 

optimization may require slightly more time. 

13. A new engineering project has been initiated in July using the Taguchi methodology. It 

is designed to result with a robust cord plate design/process. The noise experiment 

portion of the project has been completed, which has led to a clear understanding of the 

critical areas of this sub system. This project will be completed in late November of 

2001. 

Module Encapsulation 

1. Studies were conducted in order to determine whether a chemical etch could improve the 

surface qualities of the TCO to allow for better bonding to EVA. At the start, four 10 cm 

x 10 cm TCO substrates were treated with SiCl3 and SiCl4 in both liquid and vapor form 

and encapsulated with EVA and a glass cover plate. A small hole was cut in the middle 

of the EVA and filled with indicator desiccant prior to lamination. The chemical etch is 

to improve the surface qualities of the TCO to allow for better bonding to EVA. The 

samples have been placed in damp-heat testing along with a sample using bare glass only, 

for a comparison. The results indicate that the desiccant has reacted with water vapor 

after 1000 hours of damp heat testing. 

2. Additional un-encapsulated glass plates were coated with SiCl3 and SiCl4 tested in damp 

heat. After 1000 hours, the bare glass side of the plates showed some pitting while the 

coated side appeared to be undamaged. 

3. A small-scale vacuum laminator was fabricated. It is capable of encapsulating 10 cm x 

10 cm samples. Several laminations were performed using EVA with glass substrates to 

test the laminator operation. Initial results show good laminating performance, which 

signified a go-ahead for generating additional test samples for damp-heat testing. We 

have received some proprietary films from one of the vendors that we work with to begin 

the tests. 

4. Damp-heat test samples were made on 10 cm x 10 cm glass substrates laminated with 

EVA and no back sheet. Humidity indicators were imbedded in the lamination. The 

laminations were done in the new vacuum laminator by using a teflon sheet to replace the 

glass back sheet. After lamination the teflon sheet was peeled off, exposing the EVA. 

Similar samples were made with the Truseal hot melt film. Both samples were placed in 
57

damp heat to compare the effectiveness of the films as a vapor barrier. After 4 hours 

exposure, the humidity indicators on the EVA films showed signs of exposure to 

moisture. With the hot melt material 23 hours were required to show the same amount of 

moisture exposure. We are working with vendors to develop a 2-foot wide extruded 

ribbon of hot-melt sealant. We received samples of 4-inch ribbons and are in the process 

of fabricating 10 cm x 10 cm test samples. 

5. An environmental chamber relocated from Arizona has been installed in the Perrysburg 

Technical Center and became operational for thermal-cycle testing. Initial tests were to 

determine thermal expansion compatibility of back-sheet materials with the glass 

substrate. Standard-size plate samples, measuring 60 cm x 120 cm, were made with 

.001” aluminum foil, laminated to a glass substrate using an acrylic adhesive. Similar 

samples with .002” stainless steel foil were also made. A thermal cycle test was 

performed to test the effects of thermal expansion differentials between the glass and the 

foils. After one day of testing the aluminum foil began to wrinkle and de-laminate. After 

two weeks of cycling the stainless steel foil showed no visible change. 

6. In May 4” X 4” test samples were made and sent to NREL. The purpose of the test is 

two-fold. First, an adhesion test will be perform on EVA bonded to glass with several 

different deletion processes, including grit ablation, chemical etch and electrolytic etch. 

Second, the TCO glass was patterned to conduct current leakage tests after damp heat 

stress tests. Since commercial equipment was not found for chemical edge deletion, no 

follow-up has been made. 

7. First Solar investigated possibly alternative encapsulation projects with the Polymer 

Center from Battelle, Columbus, OH, and with the Southwest Research Institute (SWRI), 

San Antonio, TX. The materials identified were not commercially available and were 

high cost materials. Work was discontinued in lieu of research and developments through 

the NREL reliability team. 

During April 2001, and September 2002 modules were resubmitted to the Arizona 

Testing Laboratory with a c-channel and d-channel mounting system respectively. HF-10 

and static load testing were successful and First Solar received authorization to use the 

UL Listed mark on its FS-50c and FS-50z and FS50d modules. These are complete 

modules with mounting attachments secured to the back side. The c, d, and z 

designations indicate the style of mounting with the c denoting aluminum c-channel rails, 

the d denoting aluminum d-channel and the z denoting aluminum z-bar rails. 

 Based on the improvements that had been made over the course of this subcontract, nine 

standard production modules were submitted for testing to the Photovoltaic Testing 

Laboratory (PTL) at the Arizona State University, in accordance with the IEC standards. 

First Solar modules completed the certification testing in accordance with IEC 61646 and 

have obtained international certification. This completes the final readiness task and was 

the last open task in Subcontract ZAX-8-17647-06. 
58

6.1.3. Task 9 Milestones--- Environmental, Safety, and Health Programs 

m-3.1.3 Complete industry survey and interviews and determine what 

assistance, if any, is needed to begin the ISO 14000 planning 

(Task 9) 

m-3.2.4 Complete planning for ISO 14000 implementation (Task 9) 

m-3.3.3 Complete allocation and assignment of capital and personnel 

resources required for the ISO 14000 project 

(Task 9) 

m-3.4.5 Initiate ISO 14000 certification activities (Task 9) 

m-3.4.5 Complete comprehensive review of the First Solar PVMaT 

Environmental, Safety, and Health programs 

(Task 9) 

m-3.4.6 Complete the Phase III portion of the effort under Task 9 (Task 9) 

Milestone Description 

m-3.1.3 Complete industry survey and interviews and determine what 

assistance, if any, is needed to begin the ISO 1400 planning 

(Task 

9) 

This milestone has been completed. Support materials needed to begin the process of ISO 

14000 are available in hard copy publications as well as software packages. First Solar has 

purchased a copy of ISO 14001 Certification Environmental Management Systems by W. Lee 

Kuhre which is a book designed to provide essential information necessary to do practical 

environmental management in compliance with the ISO 14000 standard. A software 

package accompanying this book has nineteen template files containing the major procedures 

necessary to obtain an ISO certification. This is an excellent resource for gaining startup 

knowledge and certification status however, there is additional software available to better 

manage the ISO programs. 

First Solar has reviewed several ISO software packages for management of the program and 

is currently interested in the CEBOS Inc. product MQ1 software package that will 

incorporate efforts for ISO 9000 and ISO 14000 certification. 

Milestone Description 

m-3.2.4 Complete planning for ISO 14000 implementation (Task 9) 

This milestone has been completed. The following plan has been outlined for the 

implementation for ISO 14000: 

I. Steps to Achieve Certification 

• Generate a list of major applicable regulations 

• List major impacts of the operation 

• List current environmental controls 

• List additional activities needed to be added to the environmental controls 

• Estimate cost and benefits 
59

II. Environmental Elements and Components Needed 

• An environmental policy statement (purpose) must be established and agreed 

upon by all management at First Solar 

• At least one management representative must be given the authority to ensure 

implementation of the system 

• Additional employee resources will be needed, including but not limited to; 

laboratory technician, environmental engineer, and training specialist 

• Training must be provided for the environment management and all other 

employees in the organization 

• Environmental aspects and effects must be identified and corrected through; 

internal audits, monitoring data, input from employees, and outside audits 

• Risk assessment procedures must be established including but not limited to; 

immediate employee impact, immediate environmental impact, regulatory 

compliance, and long term impacts 

III. Environmental Management Programs and Operational Procedures 

• Establish procurement and vendor controls of both environmental and nonenvironmental related purchases 

• Establish an environmental review process for all equipment and chemical 

applications for the manufacturing process 

• Establish emergency procedure plan for immediate protection of employees and 

the environment in case of accidents, fires, and chemical releases 

• Establish audit procedures of the environmental system to ensure compliance with 

regulations and company policies 

• Establish document controls for all of the environmental management systems 

including but not limited to: identification of document, indexing of document, 

filing and storage of documents and removal of obsolete files 

Milestone Description 

m-3.3.3 Complete allocation and assignment of capital and personnel 

resources required for the ISO 14000 project 

Task 9) 

This milestone has been completed. The following capital and personnel resources will be 

required for the ISO 14000 project: 

• Initial software (CEBOS, MQ 1 program) = $60,000 one time cost 

• One full time employee to manage program = $55, 000 per year 

• Registration fee = $5,000 start up than $1,000 per year annual fee 

• All employee eight hours of training per year 

• Eight hours of auditing and document control for process operations per week 

Milestone Description 

3.4.5a Initiate ISO 14000 certification activities (Task 9) 

This milestone has been completed. First Solar will continue to implement documentation 

control and incorporate an environmental management system consistent with ISO 14000 
60

requirements. Effective environmental practices will be an everyday part of First Solar’s 

Environmental, Health, and Safety program however; at this time registration for the ISO 

14000 certification will not take place. With manufacturing startup problems and expected 

equipment and process changes in 2002, the logical approach will be to wait until the 

manufacturing process has stabilized to obtain this certification. 

Milestone Description 

3.4.5b Complete comprehensive review of the First Solar PVMaT 

Environmental, Safety, and Health programs 

(Task 9) 

This milestone has been completed. First Solar currently has the following (eleven) written 

Environmental, Health and Safety programs: 

Cadmium Compliance – First Solar is keenly aware of occupational and environmental 

concerns associated with cadmium and cadmium compounds. Compliance with the OSHA 

Cadmium Standard is achieved is communicated through the following training topics: 

• Communication of Cadmium Hazards and Health Effects 

• Permissible Exposure Limits for Cadmium Compounds 

• Exposure Monitoring 

• Hygiene Areas and Practices 

• Medical Surveillance 

Hazard Communication /Dot/ RCRA Training – also known as the “Right to Know” law 

established to ensure workers get information about chemical hazards in the workplace: 

• Discuss the HazCom Standard 

• Discuss the Physical and Health Hazards of Chemicals 

• Explain the DOT Hazard Classifications 

• Discus Information & Hazard Warning Labels 

• Explain the Use of the Material Safety Data Sheet (MSDS) 

Hazardous Waste Compliance - The goal of hazardous waste personnel training at First 

Solar is to teach personnel safety in regards to hazardous waste: 

• Identifying Hazardous Wastes 

• Properties of Hazardous Wastes 

• Explain the RCRA Hazardous Waste Requirements 

• Waste Minimization Procedures 

Respirator Compliance - The guidelines of this program are designed to help reduce 

employee exposure to occupational air contaminants: 

• Procedures for selecting respirators for the work place 

• Medical evaluations of employees required to use respirators 

• Procedures for cleaning, disinfecting, storing, inspecting, repairing, discarding, and 

otherwise maintaining respirators 

• Procedures for regularly evaluating the effectiveness of the program 
61

Personal Protective Equipment Compliance – it is the policy of the Company to provide 

its employees with a safe and healthful work environment. The guidelines of this program 

are designed to reduce employee exposure to occupational hazards. The primary objective is 

to assess workplace hazards and to select and provide protective equipment to protect the 

employees from the hazard. Personal protective equipment is provided at no cost to the 

employees.

Ergonomics Program – ergonomics is the science of fitting jobs to the people who work in 

them. The goal of an ergonomics program is to reduce work-related musculoskeletal 

disorders (MSDs) developed by workers when a major part of their jobs involves reaching, 

bending over, lifting heavy objects, using continuous force, working with vibrating 

equipment and doing repetitive motions. 

First Aid / Blood borne Pathogen / Means of Egress Plan – First Solar has 12 First Aid 

Responders trained for CPR, First Aid, and Prevention of Disease Transmission. The Red 

Cross provided all training programs. 

Electrical / Lockout Tag out Program – The procedure identifies electrical hazards, 

establishes safe work practices when working on or near exposure, and establishes 

requirements for locking out energy and isolation devices to ensure that the machine or 

equipment is stopped and isolated before maintenance can be performed. 

Powered Industrial Truck Operation – This program consist of a four hour class room 

lecture on safe operation of industrial trucks and identification of First Solar’s hazards. A 

driving evaluation is also required. Passage of a written test and driving test is necessary for 

all First Solar forklift drivers. 

Spill Response and Emergency Procedure Plan – A plan outline response and emergency 

procedures has been established for the First Solar Manufacturing and Technology facilities. 

Milestone Description 

m-3.4.6 Complete the Phase III portion of the effort under Task 9 (Task 9) 

Phase III portion of Task 9 has been completed. 

The objective of this activity was to continue to refine and improve the Environmental, 

Safety and Health (ES&H) programs by beginning activities related to obtaining ISO 14000 

certification. During Phase III, 16 different activities have been completed to this end, which 

are summarized below. 

3⁄4 During the First Quarter the Company conducted procurement and vendor controls 

for environmental related purchases, identified equipment and chemical approval 

tracking, updated Emergency Response Plan, and developed a Disaster Recovery 

Plan. 

3⁄4 During the Second Quarter we identified frequency and personnel involved with audit 

reviews and verification, audit procedure/compliance verification procedure, 

corrective action procedures for non-compliant items audit documentation, analyses 

of audit data, and audit reporting and management review. 
62

3⁄4 During the Third Quarter we identified data collection and handling, data collection 

procedures, data interpretation procedures, and we monitored, maintained, and 

calibrated measuring equipment. 

3⁄4 During the Fourth Quarter we developed procedures for recording and documentation 

control, conducted minimizing of discharges to air, water bodies, and sewer, 

implemented reduction of hazardous waste generation, and prepared to apply for ISO 

14000 Certification, in conjunction with current efforts of First Solar with ISO 9000 

compliance. 

3⁄4 

There were numerous specific activities, which are listed next. Frequent references are made 

to three locations where most of these activities took place. They are: 

1. Cedar Park (CP) -Manufacturing Plant 

2. Eckel Junction (EJ) -Technology Center 

3. Westwood (WW) -Pilot Plant (now decommissioned) 

Environmental 

Environmental Sampling and Monitoring: 

3⁄4 Continued air sampling the Cedar Park manufacturing facility concentrating on 

emissions from “coater” maintenance and re-build activities, the new “Arizona 

Laser,” the C24 tin oxide coater at the research facility (for tin emissions), from the 

module recycling process, and from the areas not directly related to the 

manufacturing process. 

3⁄4 Sampled and recorded the flow rate, temperature, and pH value for discharges of noncontact coolant water and completed an entire evaluation of the well discharge from 

the Cedar Park facility. 

3⁄4 Evaluated particulate dust (particle sizing) for the Cedar Park facility. 

3⁄4 Analyzed dust in the manufacturing area to gather information on fugitive dust, which 

may contain cadmium and be emitted during manufacturing and maintenance 

activities. 

3⁄4 Completed an extensive sampling profile for both the Cedar Park and Eckel Junction 

facilities for cadmium. Over (50) “wipe” samples were taken at each facility to 

determine the overall status. The data will help identify areas were fugitive dust 

maybe collecting and help establish a “housekeeping program”. 

3⁄4 Determined a chemical treatment for the cerium oxide waste generated from the 

automated buffing operation at CP. 

3⁄4 Monitored and assisted with module recycling at the Cedar Park facility. 

3⁄4 Monitored effluent discharges for the Cedar Park facility. 

Decommissioning of the Pilot Plant: 

3⁄4 Continued environmental clean up and decommissioning efforts at the Westwood 

facility, had chemicals transferred from the Westwood to the Eckel Junction and 

Cedar Park facilities. 
63

Testing, Evaluation and Equipping of Facilities: 

3⁄4 Along with the Building Engineer, evaluated the entire ventilation system for the 

Cedar Park facility and for the “Light Soak” area at the Eckel Junction facility. 

3⁄4 Sized wastewater system for the Eckel Junction facility 

3⁄4 Sized and ordered a new ventilation system for the Edge Delete system at the Cedar 

Park facility 

3⁄4 Sized and ordered a new ventilation system for the Arizona Laser #1 system at the 

Cedar Park facility 

3⁄4 Installed ventilation dust collector for the edge delete process at the Cedar Park 

Facility. 

Environmental Evaluation, Auditing and Reporting: 

3⁄4 Prepared and participated in an annual environmental inspection from the City of 

Toledo, Environmental Services Department. The inspection took place at the Cedar 

Park facility. 

3⁄4 Prepared and submitted an application to the Ohio EPA for a permit to install a 

wastewater treatment system at the Eckel Junction Research facility. 

3⁄4 Continued daily sampling of effluent discharge from the CP wastewater treatment 

system as part of a biannual reporting requirement with the City of Toledo, 

Environmental Services Department. 

3⁄4 Continued working with outside consultants to audit environmental procedures for 

both facilities. 

3⁄4 An intern from the University of Toledo began a summer internship with the EHS 

department by drafting an extensive air and wipe sampling program for both the CP 

and EJ facilities. 

3⁄4 Worked directly with a representative from NCEC (National Center for 

Environmental Communications) to audit both First Solar facilities for environmental 

issues. 

3⁄4 Started detailing an “Emission Source Report” for both facilities. 

3⁄4 Drafted a Emission Source Report for the Cedar Park Manufacturing facility. 

Health 

Health Training of Employees: 

3⁄4 Conducted cadmium training for all First Solar employees. 

3⁄4 The American Red Cross conducted training on First Aid – CPR- Bloodborne 

pathogen training for (8) employees, on CPR Refresher course for (8) employees and 

on the use of Automated External Defibrillator for (16) employees. 

Evaluation and Installation of Systems for Health and Safety: 

3⁄4 Evaluated ventilation system for the “light soak” station at the Cedar Park facility, 

and chemical lab for the Eckel Junction facility. 

3⁄4 Established an industrial noise sample study for the Cedar Park facility. 

3⁄4 Arranged for installation of ventilation systems in the Eckel Junction laboratory. 

3⁄4 Evaluated all four cells in the manufacturing facility for hazard identification and 

controls. 

3⁄4 Worked with outside contractors to design and ventilate a room for the sandblasting 

operation and roller cleaning process at the CP facility. 
64

3⁄4 Worked with outside contractors to re-design the ventilation for the EJ C-24 TCOcoating project. Explosion-proof ventilation was required for projected chemical 

application in this system. 

3⁄4 The ventilation system for the EJ C-24 project was installed. 

3⁄4 Mechanical Testing Company performed an on-site evaluation of our existing HEPA 

ventilation systems. This company has the capability of measuring particulate 

particle sizes down to 0.1 micron and will confirm that our current HEPA filtration 

system is collecting particulate matter to manufacture specifications. They will also 

assist with identifying the particulate size of dust generated in each of our processes 

and confirm that the current filtration system is adequate. 

Health Plans, Programs, and Reports: 

3⁄4 Updated Cadmium Compliance Programs for 2001. 

3⁄4 Drafted updates and changes for the First Aid and Blood borne Pathogen Programs 

3⁄4 Updated First Aid and Personal Protective Equipment Program for both facilities. 

3⁄4 Generated Industrial Hygiene plan for Cedar Park experiments involving ammonium 

hydroxide 

3⁄4 Began Industrial Hygiene Plan for new chemicals proposed for the C-24 coater at the 

EJ facility. 

3⁄4 Developed an “Industrial Hygiene Plan” to assist maintenance activities on the GDS 

to minimize cadmium exposure to employees performing the maintenance activities. 

Health Testing of Employees: 

3⁄4 (17) employees were medically evaluated as part of First Solar’s industrial hygiene 

program. 

3⁄4 30 employees received cadmium medical monitoring as part of our ongoing industrial 

hygiene plan. 

Safety 

Safety Meetings, Plans, Programs, and Reports: 

3⁄4 Continued drafting “ Return to Work Program “for both the Cedar Park and Eckel 

Junction facilities. 

3⁄4 Held Safety Council meetings every other Wednesday. 

3⁄4 Worked on “Lab Safety Program” for Eckel Junction. 

3⁄4 Discussed first aid, hazard recognition, personal protective equipment, fall protection, 

lockout-tag out issues and ergonomics programs for the Cedar Park and Eckel 

Junction facilities. 

3⁄4 Evaluated all four cells in the manufacturing facility for slip, trip, and fall hazards. 

3⁄4 Discussed labeling of all panels, breakers, and disconnects for the electrical sources at 

both the CP and EJ facilities. 

3⁄4 Evaluated current “Lockout” program for internal manufacturing procedures and 

fieldwork on outdoor arrays. 

3⁄4 Annual “Lockout-Tagout” training took place at both facilities for 36 employees at 

the CP facility and 11 employees at the EJ facility. 

3⁄4 Completed evaluation and labeling of all electrical breakers, disconnects, switches 

and outlets at the CP facility. Started similar labeling at the EJ facility. 
65

3⁄4 Zee Medical (outside consultant) performed “safety audits” at both the Cedar Park 

and Eckel Junction facilities. 

3⁄4 Modified the Contractor Guide to Safe Operations form, for all contractors working at 

First Solar facilities. 

3⁄4 Developed a facility safety audit for both facilities, that will take place bi-weekly. 

Safety Training of Employees: 

3⁄4 New employee “Safety Orientation Training” for 51 new employees. 

3⁄4 Trained and “fit tested” 27 employees for respiratory protection. 

3⁄4 Created “Lab Safety” procedures and requirements and trained 30 employees at the 

Eckel Junction facility. 

3⁄4 Annual training on Means of Egress, First Aid, Bloodborne Pathogen, Personal 

Protective Equipment, and Ergonomics was conducted for all employees. 

3⁄4 Five employees participated in Forklift Training. 

3⁄4 Six employees have been certified as Powered Industrial Truck operators.
66

7. References 

1. Joseph J. Hanak, “Laser Processing Technique for Fabricating Series-Connected 

Solar Cells into a Solar Battery,” U.S. Patent 4,292,092, September 29, 1981 

2. Robert Dickson, et al., U.S. Patent 4,892,592 

3. A.D. Compaan, I. Matulionis, S. Nakade, U. Jayamaha, “Pulse Duration and 

Wavelength Effects in Laser Scribing of Thin-Film Polycrystalline PV Materials,” 

NREL/SNL Photovoltaic Program Review, edited by C. Edwin Witt, M. Al-Jassim, 

and J.M. Gee,  1997 AIP Press, New York, pp. 567-571 

4. I. Matulionis, S. Nakade, A.D. Compaan, “Wavelength and Pulse Duration Effects 

in Laser Scribing of Thin Films,” Conference Record of the IEEE 26th Photovoltaic 

Specialists Conference, Anaheim, CA, Sept. 30-Oct. 3, 1997, p. 491. 

5 David Carlson, et al, “Electrical Contacts for a Thin-Film Semiconductor Device”, 

U.S. Patent 4,854,974, August 8, 1989. 

 
REPORT DOCUMENTATION PAGE Form Approved 

 OMB NO. 0704-0188 

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, 

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1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE

January 2004 

3. REPORT TYPE AND DATES COVERED 

Final Subcontract Report 

March 2003 

4. TITLE AND SUBTITLE

 Specific PVMaT R&D in CdTe Product Manufacturing: Final Subcontract Report, 

 March 2003 

6. AUTHOR(S) 

 J. Bohland, A. McMaster, S. Henson, and J. Hanak 

5. FUNDING NUMBERS

PVP46101 

ZAX-8-17647-06 

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 

First Solar, LLC 

 28101 Cedar Park Blvd. 

 Perrysburg, Ohio 43551

8. PERFORMING ORGANIZATION 

REPORT NUMBER 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Renewable Energy Laboratory 

1617 Cole Blvd. 

Golden, CO 80401-3393

10. SPONSORING/MONITORING 

AGENCY REPORT NUMBER

NREL/SR-520-35177 

11. SUPPLEMENTARY NOTES

NREL Technical Monitor: R.L. Mitchell 

12a. DISTRIBUTION/AVAILABILITY STATEMENT

National Technical Information Service 

U.S. Department of Commerce 

5285 Port Royal Road 

 Springfield, VA 22161

12b. DISTRIBUTION CODE

 

13. ABSTRACT (Maximum 200 words): Results of a 3+ year subcontract are presented. The research was conducted under 

Phase 5A2 of the subcontract. The three areas of effort in the subcontract were 1) manufacturing line improvements, 2) product readiness, 

and 3) environmental, safety, and health programs. The subcontract consisted of three phases, approximately 1 year each. Phase I included 

the development, design, and implementation of a high-throughput, low-cost lamination process. This goal was achieved using the support 

of key experts such as Automation and Robotics Research Institute (ARRI) to identify appropriate lamination equipment vendors, and 

material handling. Product designs were reviewed by Arizona State University Photovoltaic Testing Laboratory and Underwriters 

Laboratories. Modifications to the module designs were implemented to meet future testing requirements. A complete review of the 

Environmental, Health, and Safety programs was conducted, along with training by the Environmental Protection Agency (EPA) and 

Occupational Safety and Health Administration (OSHA). Work conducted during Phase II included the implementation of an improved 

potting procedure for the wiring junction. The design of the equipment focused on high-throughput, low-cost operations. During Phase III , 

First Solar made significant progress in three areas: Manufacturing Readiness; Product Performance; and Environmental, Health, and 

Safety (EH&S). First Solar’s accomplishments in laser scribing significantly exceeded the stated goals. Innovations implemented during 

Phase III were made possible by adopting a new type of high-frequency, low-pulse-width laser, galvanometer-driven laser-beam system, 

and numerous advanced, automated, equipment features. Because of the greater than one order of magnitude increase in the throughput 

and laser life, a factor of two decrease in equipment cost, and complete automation, a major impact on lowering the cost of the PV product 

is anticipated. 

15. NUMBER OF PAGES

14. SUBJECT TERMS: PV; manufacturer; manufacturing line improvements; product 

readiness; lamination process; wiring junction; cost reduction; laser scribing; module. 16. PRICE CODE

17. SECURITY CLASSIFICATION 

OF REPORT

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18. SECURITY CLASSIFICATION 

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19. SECURITY CLASSIFICATION 

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20. LIMITATION OF ABSTRACT

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 NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89) 

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