bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inverse Derivation of Constants for the Constitutive Equation and Fatigue Model of Pb-Free Solder Joints Based on Experiment Results, Finite Element Simulation and Virtual Optimization Methodology
Authors: Xie Weidong , Ahmad Mudasir 
Published: October 2013

Solder joint reliability of Pb-free ball grid array (BGA) components, one of the most commonly used microelectronic devices, is one of the major concerns in product development and qualification. Accelerated Thermal Cycling (ATC) testing, though very time consuming and costly, remains the most prevalent means to evaluate solder joint reliability under certain end-use conditions. Wherever the test results are not readily available, a fine-tuned and well-benchmarked modeling methodology is of significance in producing quick-turn judgments and risk assessments to expedite product development.
The two most critical elements in simulating solder joint reliability are 1) the solder constitutive equations, which describe the solder creep behavior under different working conditions, and 2) the fatigue model which ties the damage index from finite element modeling together with the experimental results. In this study, a novel approach has been explored in which the constants of the constitutive equation and fatigue model for Sn-based Pb-free solder joints were derived inversely based on ATC results of a ceramic BGA test vehicle. In order to cover the typical end-use conditions of the targeted products, the test vehicle was assembled onto PCBs with two different thicknesses and then thermal cycled under three different temperature profiles. The basic idea was that all of the constants, both for the constitutive equation and the fatigue life prediction model, were initially given as a range. Then by utilizing modeFrontier®, a multi-objective optimization software, the finite-element model was coupled with the virtual optimization algorithm to derive simultaneously all the constants that yielded the best fatigue life predictions compared to the test results. To simplify the problem without compromising the generality, a hyperbolic sine creep constitutive equation and Coffin-Manson fatigue model were selected in the analysis. There were a total of 6 constants to be determined; the initial ranges of the constants were defined by fitting the creep experimental data for a variety of Sn-based solder materials. Available in other publications, the selected solder materials cover a wide range of both Ag and Cu content which therefore represent the typical behavior of the most commonly adopted solder materials by the industry. To reduce the computational cost and enable fast convergence of multiple-generation iterations required by the multiple objective optimization algorithms, a very-well benchmarked submodel has been employed. Furthermore, by utilizing ANSYS® high performance computing (HPC) capability and cloud computing, the computational time was reduced significantly. An overall good correlation was achieved between the fatigue life prediction using the constants derived by this approach and the test characteristic life.
Study on the Flange Manufacturing of Pipe With High Pressures
Authors: Baek SeungGul , Song XueGuan , Park YoungChul , Kim TaeGual , Park KyoungYong , Kim KwangSun 
Published: October 2013

Pipe flanges are usually welded or screwed to the pipe end and are connected with bolts. This approach is very simple and widely used for a long time, however, it results in high development cost and low productivity and some safety problems at the welding area. In this research, a new approach of forming pipe flange based on cold forging and floating die concept is presented. This innovative approach increases the effectiveness of the material usage and save the time cost compared with conventional welding method.
To ensure the dimensional accuracy of the final product, finite element analysis are carried out to simulate the process of cold forging, and orthogonal experiments method are used to investigate the influence of four manufacturing factors and predict the best combination of them. In addition, a real product is manufactured in terms of the best factors predicted by FEA and optimization method to validate the proposed approach. The experimental results show that the approach is effective for the forming of pipe flange, and can be widely used later.
Implementing a Cohesive Zone Interface in a Diamond-Coated Tool for 2D Cutting Simulations
Authors: Qin Feng , Shen Ninggang , Chou Kevin 
Published: October 2013

Coating-substrate interface properties and deposition residual stresses may have significant effects on diamond-coated tool performance. However, it is still distant to understand how the interface mechanical behavior and deposition residual stress together influence the diamond-coated tool thermo-mechanical behavior during machining. In this study, a 2D cutting simulation incorporating deposition residual stresses and an interface cohesive zone model has been developed to demonstrate the feasibility of evaluating coating delamination of a diamond-coated tool during cutting.
It has been shown that even the residual deposition stresses alone may result in crack initiations in the cohesive zone (i.e., the interface). In addition, the study further demonstrates that the feasibility of implementing cohesive zone interface in a diamond-coated tool in 2D cutting simulation. An example of cohesive failure occurred in the cutting simulation is shown. The result shows a large uncut chip thickness can cause cohesive delamination during cutting.
Application of Binary Fluid Ejector in Thermal Vapor Compression Distillation Systems
Authors: Shahamiri S. Ali , Salek M. Mehdi , May Wayne , Martinuzzi Robert J. 
Published: October 2013

Ejector Refrigeration Systems (ERS) offer the use of low grade energy sources. These systems are simple in principle; however, suffer from relatively low COP, mainly due to inefficient energy exchange between the primary and secondary fluid flows in the ejector. The use of two chemically distinct fluids in forward and reversed Rankine cycles of such systems has been shown to improve COP. These systems are known as Binary Fluid ERS (BFERS).
This paper focuses on the application of BFERS for the purpose of water distillation. First, a model for an ideal ejector was developed and the maximum theoretical COP of the system was determined. Actual COP of the system was also estimated by computing the entrainment ratio in the ejector using computational fluid dynamic modeling (CFD). The effects of certain fluid properties such as molecular masse and specific heat ratio of the two fluids were investigated with respect to mass entrainment ratio. A number of guidelines for the selection of suitable primary and secondary fluids were developed based on research literature and the potential for increasing COP through the use of chemically distinct fluids, i.e. binary operating fluids.
Development of a 240,000 kg/Day Hydrogen Pipeline Centrifugal Compressor for the Department of Energy’s Hydrogen Delivery and Production Program
Authors: Di Bella Francis A. , Fairman Kevin D. 
Published: October 2013

Concepts NREC has completed the detailed design of a six-stage hydrogen compressor rated for industrial gas pipeline service. A single-stage prototype system has also been designed to enable the controlled laboratory testing of the mechanical elements of the compressor subsystems. The project has successfully met the Department of Energy’s technical objectives including:
• Develop and demonstrate an advanced centrifugal compressor system for high-pressure hydrogen pipeline transport to support the DOE’s strategic hydrogen economy infrastructure plan.
• Deliver 100,000 to 1,000,000 kg/day of 99.99% hydrogen gas from generation site(s) to forecourt stations.
• Compression from 350 psig to 1,000 psig or greater.
• Reduce initial installed system equipment cost to less than $9M (compressor package of $5.4M) for 240,000 kg/day system by FY 2017.
• Reduce package footprint and improve packaging design.
• Achieve transport delivery costs below $1–2/GGE (the DOE’s target as given in the original FOA).
• Reduce maintenance cost to below 3% of Total Capital Investment by FY 2017.
• Increase system reliability to avoid purchasing redundant systems.
• Maintain hydrogen efficiency (as defined by the DOE equal to 1-Compression Specific Energy/Hydrogen High Heating Value) to 98% or greater.
• Reduce H2 leakage to less than 0.5% by FY 2017.
Inhomogeneous Deformation Examples and Applications of Light Activated Shape Memory Polymers
Authors: Sodhi Jaskirat S. , Moon Swapnil , Rao I. Joga 
Published: October 2013

Light Activated Shape Memory Polymers (LASMP) are recently developed innovative materials defined by their capacity to store a deformed (temporary) shape and recover an original (parent) shape. This change in shape and the return to original shape is achieved by exposing the polymer to light at different wavelengths. These unique properties have led to the use of LASMP’s in a wide variety of applications. These SMP’s have a great potential in the biomedical industry as well as the aerospace industry.
In the past, the authors have introduced a constitutive model to model the mechanics of these LASMP [1] and used it to solve a few cases of boundary value problems of interest. In this paper, the developed model is used to solve some other inhomogeneous deformation boundary value problems.
High Performance MEMS Thermal Gyroscope
Authors: Zarei Nilgoon , Leung Albert M. , Jones John D. 
Published: October 2013

This paper reports modeling a new design of Thermal MEMS gyroscope through the use of the Comsol Multiphysics software package. Being very small and having no movable parts have made thermal MEMS gyroscope very practical. Previously designed Thermal MEMS gyroscope shows some limitation such as being vulnerable to gravity force. Finding a technique to increase the range of thermal MEMS gyroscope reliability motivated us to come up with a new design that we will refer to as the ‘Forced Convection MEMS gyroscope’. A two-dimensional finite-element model of the device has been developed to investigate its performance. An external force has been introduced to the system to create a higher-velocity hot gas stream that will be deviated more in response to rotation. The external force should be great enough that convection currents resulting from gravity or acceleration will have minimal impact on the gyroscope sensitivity. A heating element can still be used, but its primary purpose is now to warm the flowing gas so that it can be detected by the sensors. In this paper we will also show that, in order to completely eliminate the impact of gravity and increase the sensitivity of the gyroscope, it is possible to eliminate the heaters entirely and instead use heated sensors to detect gas currents. In other words, the sensors are working as hot-wire anemometers. Our simulations suggest that this design variant results in higher sensitivity. We have also carried out optimization studies to identify the best location for the heaters and sensors.
A prototype of this device has been fabricated based on MEMS techniques, and an external pump is used to produce an oscillating gas flow within the device.
Thermoelectric-Based Power Generator for Powering Microcontroller Based Security Camera
Authors: Dell Robert , Unnthorsson Runar , Wei C. S. , Sidebotham George W. , Jonsson Magnus Thor , Foley William , Ginzburg Eric , Paul Subashis , Kim Seyoon , Morris Anthony 
Published: October 2013

This paper presents the design, implementation and evaluation of a thermoelectric-based point of use power generation system with no moving parts. The power system was designed to be robust and stable, capable of being clamped onto the outer wall of a hot steam pipe with a temperature of over 160°C using only heat pipes and natural convection of ambient air for cooling.
Several systems were built and tested. One system was built and tested at the Cooper Union in New York City. The power generation was evaluated for different ambient and steam pipe temperatures. The other systems were attached to an 85°C geothermal hot water pipe and a 100–120°C geothermal steam pipe in Iceland. The Cooper Union system was used to power two microcontroller based security cameras, one with wireless LAN and another with cellular connectivity. Additional testing of the PV voltage controller and the generator were conducted in Iceland.
The results show that the system can be used to power surveillance systems, even in remote locations without access to the electrical grid. Because the system does not require grid access, it will run constantly, and hence improve security. Furthermore, the unit’s power generation is greater in colder environments that substantially degrade battery performance.
Evaluation of a Novel Anisotropic Conductive Adhesive Shear Under Multiple Tin-Lead and Lead-Free Reflow Cycles for Package-on-Package (POP) Assembly
Authors: D’Angelo Dustin , Ramkumar S. Manian , Wentlent Luke , Borgesen Peter 
Published: October 2013

The continued desire for an alternative to lead-based solder materials for electrical interconnections has led to significant research interest in Anisotropic Conductive Adhesives (ACAs). These create bonds using a combination of metal particles and epoxies to replace solder. The novel ACA discussed in this paper allows for bonds to be created through aligning columns of conductive particles along the Z-axis. These columns are formed by the application of a magnetic field, during the curing process. The benefit of this novel ACA is that it does not require precise printing of the adhesive on pads and also enables the mass curing without creating shorts in the circuitry.
The novel ACA’s applicability for PCB-level assembly has been successfully demonstrated by RIT. The research at RIT has also characterized the base material properties, analyzed the effect of various process parameters, identified failures, and investigated the ACA’s long-term reliability for surface mount PCB assembly. Reliability testing included an investigation of the assembly performance in temperature and humidity aging, thermal aging, air-to-air thermal cycling, and drop testing conditions. For example, it has been shown that by modifying the filler particle size and coating, reliability of >1500 hours in high temperature, high humidity aging (HTHH), and 100 hours in highly accelerated stress testing (HAST) can be successfully achieved.
This paper highlights research comparing the shear loading performance of the novel ACA to that of tin-lead and lead free solders. Samples assembled with the adhesive and the solders were subjected to multiple tin-lead and lead free reflow cycles. The primary objective was to understand the deterioration in shear loading as influenced by multiple reflow cycles. Published research materials have shown the influence of the change in solder joint performance with multiple reflows due to the increase in intermetallic thickness. The results of a DOE study show the influence of the various factors and levels. Shear stress calculations indicate higher stress experienced by the adhesive joints as compared to the solder joints due to the spreading of the solder during wetting. Empirical relationships will be derived from the experimental data to help determine the required contact area for a given level of shear loading. The experimental results also reveal the rapid decrease in Shear stress between the first and second reflow and the slow decline in strength up to five reflows. Findings from this work will be used to assess the use and reliability of this adhesive for attaching the top component of Package-on-Package (PoP) 3D stacked components, in thermal cycling, HAST and HTHH environments.
Thermal Conductivity Performance Modeling and Characterization of a Novel Anisotropic Conductive Adhesive Used in Lead-Free Electronics Packaging
Authors: Combs Matthew J. , Ramkumar S. Manian , Kandlikar Satish 
Published: October 2013

The continued desire to utilize an alternative to lead-based solder materials for electrical interconnections has led to significant research interest in Anisotropic Conductive Adhesives (ACAs). The use of ACAs in electrical connections creates bonds using a combination of metal particles and epoxies to replace solder. The novel ACA discussed in this paper allows for bonds to be created through aligning columns of conductive particles along the Z-axis. These columns are formed by the application of a magnetic field, during the curing process. The benefit of this novel ACA is that it does not require precise printing of the adhesive on pads and also enables the mass curing without creating shorts in the circuitry.
This paper will present the findings of the thermal conductivity performance tests using the novel ACA and its applicability as a thermal interface material and for assembling bottom termination components, power devices, etc. The columns that act as electrical conduction paths also contribute towards the thermal conductivity. The thermal conductivity of the novel ACA was measured utilizing a system that is similar to that in ASTM (American Society of Testing Materials) D5470 standard. The goal was to examine the influence of Bond Line Thickness (BLT), particle loading densities, particle diameters and adhesive matrix curing conditions on the electrical and thermal performance of the novel ACA. This paper will also present a numerical model to describe the thermal behavior of the novel ACA.
The novel ACA’s applicability for PCB-level assembly has also been successfully demonstrated by RIT, including base material characterization, effect of process parameters, failures, and long-term reliability. Reliability testing included the investigation of the assembly performance in temperature and humidity aging, thermal aging, air-to-air thermal cycling, and drop testing.
Creep Strain Measurement of an Actual Leadfree Solder Interconnect Using Digital Image Correlation
Authors: Lee Hohyung , Park Seungbae 
Published: October 2013

Creep behavior of the solder joint is one of the critical concerns in reliability of the electronic package, especially above half of the homologous temperatures. Considering melting point of the lead free solder alloys, creep deformation can be dominantly occur even at room temperature.
Among the three phase of the creep curve, the steady state strain rate in secondary phase is the most important design parameter to predict life time of the solder joint. To measure the strain rate of the solder during the creep deformation, several studies conducted creep test using bulk solder samples. However, mechanical properties of the bulk solder are different from actual solder joint due to its microstructure and intermetallic layer. Thus, creep behavior of the actual solder ball need to be measured to obtain the realistic creep data. In this study, the constant creep rate of the actual solder ball in ball grid array (BGA) packages is measured using 2D Digital Image Correlation (DIC) measurement technique.
Three lead free BGA packages, SAC105, SAC305 and Sn/Cu/Ni alloy (SCN) are used for the creep test. While 9.78 N, 19.56 N, and 29.34 N of the compressive loads are applied at 20°C, 40°C, 60°C and 90°C to each type of the specimen, a microscopic images of the cross sectioned surface of the solder ball are captured. The series of images are sequentially taken during the predetermined time interval and transferred to DIC software to generate full-filled surface displacement data. From the displacement data, constant creep rate of the actual solder ball is acquired.
Multi-Scale Transient Thermal Analysis of Microelectronics
Authors: Barabadi Banafsheh , Kumar Satish , Sukharev Valeriy , Joshi Yogendra K. 
Published: October 2013

Thermal transport in microelectronic devices spans length scales from tens of nanometers to hundreds of millimeters. One of the major challenges in maintaining quality and reliability in today’s microelectronic devices comes from the ever increasing level of integration in the device fabrication as well as the high level of current densities that are carried through the microchip during operation. Consequently, significant opportunities for energy efficiency exist at various levels of the length scale hierarchy by optimization of thermal management resources.
In this study, we developed a computationally efficient and accurate multi-scale reduced order transient thermal methodology consisting of hybrid implementation of two different multi-scale approaches: 1. “Progressive Zoom-in” method and 2. “Proper Orthogonal Decomposition (POD)” technique. The suggested approach provides the ability to predict different thermal scenarios based on one representative thermal scenario, while maintaining the desired spatial and temporal accuracy. In this paper, a Flip Chip Ball Grid Array (FCBGA) package was considered for hybrid modeling. To demonstrate the capability of POD method in predicting different thermal scenarios, the chip is divided into ten function blocks. Each of these blocks had a different randomly generated dynamic power source. To validate this methodology, the results were compared with a finite element (FE) model developed in COMSOL®. The behavior of the POD model was in good agreements with the corresponding FE model. This close correlation provides the capability of predicting other thermal scenarios based on a smaller sample set which can significantly decrease the computational cost.
Design for Manufacture and Assembly Lean and Product Development Through Industrial Case Study
Authors: Dwivedi Suren N. , Attarwala Pinkeshkumar J. 
Published: October 2013

Lean is a key process that understands customer value and its goal is to provide perfect value to the customer by engaging a process cycle that minimizes waste. This paper focuses on the implementation of Lean in the Design and Manufacturing Industries. The complex interactions of the financial, logistical, and geological processes that are involved in developing a product and then handing it over to customers are driving forces in today’s industries. Hence, if industries do not implement Lean, product cost will rise.
Lean design involves identifying wastage in the processes of product manufacturing/production. This means, specifically, eliminating waste and non-value-added activities in design, production, marketing, supply chain integration and customer interactions by making product flow through the Value Stream without any interruption. Our goal is to minimize production resources by eliminating non-value-added activities, thus saving time in production and improving product quality.
The basic goal behind this paper is to reduce product cost by eliminating unnecessary elements that increase final product cost. This will be demonstrated by way of manufacturing a fuel tank by removing or redesigning the parts now used by the current industry.
The paper also will show how Virtual Reality plays a key role in helping students and engineers to learn applications and to understand simulation more effectively. It is a powerful learning tool for both engineers and students. The paper will emphasize the development of active learning experiences in relation to Lean Product Development. The different models that are developed in this paper will help students and engineers to gain knowledge in various streams like Engineering, Business and Sciences, with the aid of Virtual Reality. This paper concentrates mainly on undergraduate and graduate students. Solid Works, one of the more common and available tools in most U.S. schools, is utilized as a software that allows users to change product designs on their own, so as to get better results. After learning these tools, users will be able to apply their skills in various industries to reduce non-value-added activities. Developing Lean Manufacturing models using Virtual Reality will increase any user’s capability, quality and efficiency in Product Development.