Reliability Evaluation on Deterioration of Power Device Using Coupled Electrical-Thermal-Mechanical Analysis

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Takashi Anzawa ◽  
Qiang Yu ◽  
Masanori Yamagiwa ◽  
Tadahiro Shibutani ◽  
Masaki Shiratori
Keyword(s):  
Thermal Analysis ◽  
Fatigue Life ◽  
Temperature Distribution ◽  
Simulation Method ◽  
Thermomechanical Analysis ◽  
Mechanical Analysis ◽  
Power Module ◽  
Insulated Gate Bipolar Transistor ◽  
Power Cycling ◽  
Thermal Mechanical Analysis

This paper presents a simulation method to evaluate the thermal fatigue life of a power module. A coupled electrical-thermal analysis was performed to obtain the nonuniform temperature distribution of electric current. Then, a thermomechanical analysis was carried out based on the temperature distribution from the electrical-thermal analysis. Since crack propagation can change the route of heat transfer, a crack path simulation technique was used to investigate the fracture behavior of the power module. The crack initiates in the solder joint below the Al bonding wire of the insulated gate bipolar transistor module and propagates by increasing the diameter. The effect of the bonding type on power cycling fatigue life is also discussed. The fracture process was found to depend on the type of bonding. Lead frame bonding was found to be more effective than wire bonding.

Precision Evaluation for Thermal Fatigue Life of Power Module Using Coupled Electrical-Thermal-Structural Analysis

2011 ◽  
Author(s):  
Tomohiro Takahashi ◽  
Qiang Yu ◽  
Masahiro Kobayashi
Keyword(s):  
Fatigue Life ◽  
Temperature Distribution ◽  
Solder Joint ◽  
Thermal Fatigue ◽  
Thermal Structure ◽  
Inelastic Strain ◽  
Power Module ◽  
Thermal Fatigue Life ◽  
Power Cycling ◽  
Precision Evaluation

For power module, the reliability evaluation of thermal fatigue life by power cycling has been prioritized as an important concern. Since in power cycling produces there exists non-uniform temperature distribution in the power module, coupled thermal-structure analysis is required to evaluate thermal fatigue mechanism. The thermal expansion difference between a Si chip and a substrate causes thermal fatigue. In this study, thermal fatigue life of solder joints on power module was evaluated. The finite element method (FEM) was used to evaluate temperature distribution induced by joule heating. Higher temperature appears below the Al wire because the electric current flows through the bonding Al wire. Coupled thermal-structure analysis is also required to evaluate the inelastic strain distribution. The damage of each part of solder joint can be calculated from equivalent inelastic strain range and crack propagation was simulated by deleting damaged elements step by step. The initial cracks were caused below the bonding Al wire and propagated concentrically under power cycling. There is the difference from environmental thermal cycling where the crack initiated at the edge of solder layer. In addition, in order to accurately evaluate the thermal fatigue life, the factors affecting the thermal fatigue life of solder joint where verified using coupled electrical-thermal-structural analysis. Then, the relation between the thermal fatigue life of solder joint and each factor is clarified. The precision evaluation for the thermal fatigue life of power module is improved.

Shorter Field Life in Power Cycling for Organic Packages

2006 ◽  
Vol 129 (1) ◽  
pp. 28-34 ◽  
Author(s):  
S. B. Park ◽  
Izhar Z. Ahmed
Keyword(s):  
Fatigue Life ◽  
Temperature Distribution ◽  
Flip Chip ◽  
Coefficient Of Thermal Expansion ◽  
Uniform Temperature ◽  
Transfer Coefficients ◽  
Solder Interconnects ◽  
Power Cycling ◽  
Plastic Ball ◽  
Accelerated Thermal Cycling

The importance of power cycling as a mean of reliability assessment was revisited for flip chip plastic ball grid array (FC-PBGA) packages. Conventionally, reliability was addressed empirically through accelerated thermal cycling (ATC) because of its simplicity and conservative nature of life prediction. It was well accepted and served its role effectively for ceramic packages. In reality, an assembly is subjected to a power cycling, i.e., nonuniform temperature distribution with a chip as the only heat source and other components as heat dissipaters. This non-uniform temperature distribution and different coefficient of thermal expansion (CTE) of each component make the package deform differently than the case of uniform temperature in ATC. Higher substrate CTE in a plastic package generates double curvature in the package deformation and transfers higher stresses to the solder interconnects at the end of die. This mechanism makes the solder interconnects near the end of die edge fail earlier than those of the highest distance to neutral point. This phenomenon makes the interconnect fail earlier in power cycling than ATC. Apparently, we do not see this effect (the die shadow effect) in ceramic packages. In this work, a proper power cycling analysis procedure was proposed and conducted to predict solder fatigue life. An effort was made for FC-PBGA to show the possibility of shorter fatigue life in power cycling than the one of ATC. The procedure involves computational fluid dynamics (CFD) and finite element analyses (FEA). CFD analysis was used to extract transient heat transfer coefficients while subsequent FEA–thermal and FEA–structural analyses were used to calculate temperature distribution and strain energy density, respectively.

scholarly journals Thermal analysis study of polymer-to-ceramic conversion of organosilicon precursors

2008 ◽  
Vol 44 (1) ◽  
pp. 35-38 ◽  
Author(s):  
D. Galusek ◽  
Z. Lencés ◽  
P. Sajgalík ◽  
Ralf Riedel
Keyword(s):  
Thermal Analysis ◽  
Mechanical Analysis ◽  
Cross Linking ◽  
Oxide Ceramics ◽  
Ceramic Yield ◽  
Scanning Calorimetry ◽  
Analysis Study ◽  
Thermal Analysis Study ◽  
Thermal Mechanical Analysis ◽  
Significant Attention

The organosilicon precursors attract significant attention as substances, which upon heating in inert or reactive atmosphere convert directly to oxide or non-oxide ceramics, like nitrides, carbides, carbonitrides, boroncarbonitrides, oxycarbides, alons, etc. In characterisation, and in study of conversion of these polymers to ceramics thermal analysis plays an important role. The degree of cross-linking of the polymer vital for achievement of high ceramic yield is estimated with the use of thermal mechanical analysis (TMA). Decomposition of polymers and their conversion to ceramics is studied by the combination of differential thermal analysis (DTA), differential scanning calorimetry (DSC) thermogravimetry(TG), and mass spectrometry (MS). The use of these methods in study of the polymer-to-ceramic conversion is illustrated by case studies of a commercially available poly(allyl)carbosilane as the precursor of SiC, and a poly(hydridomethyl)silazane as the precursor of SiCN.

Thermal-Mechanical Analysis of Hybrid Spindle System Based on FEM

2012 ◽  
Vol 565 ◽  
pp. 644-649 ◽  
Author(s):  
Wan Shan Wang ◽  
Peng Guan ◽  
Tian Biao Yu
Keyword(s):  
High Speed ◽  
Simulation Method ◽  
Mechanical Analysis ◽  
Grinding Force ◽  
Digital Design ◽  
Structural Deformation ◽  
Spindle System ◽  
Ultra High Speed ◽  
High Speed Grinding ◽  
Thermal Mechanical Analysis

The deformation of the spindle system is the main factor affecting the accuracy of ultra-high speed grinding. To calculate the deformation of ultra-high-speed grinding spindle system is required to consider not only the formation of structural deformation, but also the thermal deformation. Using the simulation method, oil temperature and grinding force are calculated in this paper. Based on these two factors, the thermal-mechanical deformation of the hybrid spindle system is analyzed and calculated with the method of FEM. the This article uses simulation methods, analysis and calculation of the oil film temperature rise and the grinding force caused by deformation of the liquid and hydrostatic spindle system factors. The methods presented in this paper can be used in digital design of various kinds of spindle systems, in order to improve the accuracy of the spindle system design.

A Thermal-Mechanical Analysis Model for Composite Overwrapped Pressure Vessel for Hydrogen During Fast Filling

2019 ◽  
Author(s):  
Y. Jiang ◽  
M. Xu ◽  
Zhichao Fan ◽  
Chen Xuedong ◽  
Q. G. Wu
Keyword(s):  
Temperature Distribution ◽  
Pressure Vessel ◽  
Three Dimensional ◽  
Element Model ◽  
Mechanical Analysis ◽  
Cfd Model ◽  
Analysis Model ◽  
Temperature Increment ◽  
Thermal Mechanical Analysis ◽  
Metallic Liner

Abstract Composite overwrapped pressure vessel (COPV) is considered to be the most promising storage tank for hydrogen. Filling the COPV to high pressure within 3–5 minutes generates temperature increment due to negative Joule-Thomson coefficient and compression effect of hydrogen. This temperature increment induces a non-uniform temperature distribution in the COPV. The difference between the physical properties of inner metallic liner and outer composite will produce thermal stress. In this work a computational fluid dynamics (CFD) model is built to simulate the temperature increment during fast filling of the COPV. A three-dimensional thermal-mechanical finite element model for COPV is set up. The temperature distribution of the COPV by the CFD model is input into the thermal-mechanical model to analyze the stress distribution during the fast filling. This thermal-mechanical analysis model will provide technical support for the design of COPV.

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