Analysis of Transient Thermal Stress of IGBT Module Based on Electrical-Thermal-Mechanical Coupling Model

2014 ◽  
Vol 986-987 ◽  
pp. 823-827
Author(s):  
Qing Yuan Zheng ◽  
Min You Chen ◽  
Bing Gao ◽  
Nan Jiang
Keyword(s):  
Thermal Stress ◽  
Stress Distribution ◽  
Uniform Distribution ◽  
Inelastic Strain ◽  
Coupling Model ◽  
Power Module ◽  
Mechanical Coupling ◽  
Fem Method ◽  
Igbt Module ◽  
Solder Layer

Reliability of IGBT power module is one of the biggest concerns regarding wind power system, which generates the non-uniform distribution of temperature and thermal stress. The effects of non-uniform distribution will cause failure of IGBT module. Therefore, analysis of thermal mechanical stress distribution is crucially important for investigation of IGBT failure mechanism. This paper uses FEM method to establish an electrical-thermal mechanical coupling model of IGBT power module. Firstly, thermal stress distribution of solder layer is studied under power cycling. Then, the effects of initial failure of solder layer on the characteristic of IGBT module is investigated. Experimental results indicate that the strain energy density and inelastic strain are higher which will reduce reliability and lifetime of power modules.

Electromigration Analysis of Solder Joints for Power Modules Using an Electrical-Thermal-Stress Coupled Model

2021 ◽  
Author(s):  
Mitsuaki Kato ◽  
Takahiro Omori ◽  
Akihiro Goryu ◽  
Tomoya Fumikura ◽  
Kenji Hirohata
Keyword(s):  
Thermal Stress ◽  
Solder Joint ◽  
Power Output ◽  
Solder Joints ◽  
Vacancy Concentration ◽  
Inelastic Strain ◽  
Power Device ◽  
Power Module ◽  
Power Modules ◽  
Rate Of Increase

Abstract Power modules are being developed to increase power output. The larger current densities accompanying increased power output are expected to degrade solder joints in power modules by electromigration. In previous research, numerical analysis of solder for electromigration has mainly examined ball grid arrays in flip-chip packages in which many solder balls are bonded under the semiconductor device. However, in a power module, a single solder joint is uniformly bonded under the power device. Because of this difference in geometric shape, the effect of electromigration in the solder of power modules may be significantly different from that in the solder of flip chips packages. This report describes an electromigration analysis of solder joints for power modules using an electrical-thermal-stress coupled analysis. First, we validate our numerical implementation and show that it can reproduce the vacancy concentrations and hydrostatic stress almost the same as the analytical solutions. We then simulate a single solder joint to evaluate electromigration in a solder joint in a power module. Once inelastic strain appears, the rate of increase in vacancy concentration slows, while the inelastic strain continuously increases. This phenomenon demonstrates that elastic-plastic-creep analysis is crucial for electromigration analysis of solder joints in power modules. Next, the solder joint with a power device and a substrate as used in power modules was simulated. Plasticity-creep and longitudinal gradient generated by current crowding have a strong effect on significantly reducing the vacancy concentration at the anode edge over a long period of time.

Numerical simulation of the metal inert gas welding process that considers grain heterogeneity

2020 ◽  
pp. 146442072094991
Author(s):  
Chang Li ◽  
Zhengwei Chen ◽  
Hexin Gao ◽  
Dacheng Zhang ◽  
Xing Han
Keyword(s):  
Thermal Stress ◽  
Stress Distribution ◽  
Thermal Stresses ◽  
Statistical Significance ◽  
Voronoi Tessellation ◽  
Welding Process ◽  
Vertical Direction ◽  
Inert Gas ◽  
Mechanical Coupling ◽  
Metal Inert Gas Welding

It is of great significance to reveal the microevolution mechanism of welded structures during thermo-mechanical coupling to improve the welding quality. In this paper, a random microcrystalline structure model for welds is established by the Voronoi tessellation method. According to the nanoindentation results, heterogeneous grains are produced. A welding workpiece model with statistical significance is established. On this basis, the Python script and the birth and death element method are used to realize the transient growth of a weld, and a thermo-mechanical coupling model for the SUS301L-HT stainless steel metal inert gas welding process is established. The temperature field and thermal stress field are calculated. The calculation shows that the thermal stresses along the growth direction of the weld area are in the form of a “trapezoid,” and the stresses at both ends are small. The stress in the vertical direction of the weld has a single peak, and the peak appears in the center of the weld. The stress distribution of the model that considers heterogeneous grains is obviously inhomogeneous compared with that of the traditional model. The thermal stress distribution in the weldment is obviously inhomogeneous due to the heterogeneous grains, the stresses at the boundaries of the adjacent grains in the weldment change abruptly. It is found that the greater the difference in the mechanical properties between grains is, the more obvious the change.

Numerical Simulation of Laser Thermal Stress Forming of Thin Steel Sheet

2010 ◽  
Vol 160-162 ◽  
pp. 1414-1419
Author(s):  
Mao Ke Tao ◽  
Zong Bao Shen ◽  
Cheng Zhang ◽  
Kai Wang
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Laser Scanning ◽  
Steel Sheet ◽  
Coupling Model ◽  
Forming Process ◽  
Mechanical Coupling ◽  
State Process ◽  
Thin Steel Sheet ◽  
Thin Steel

Laser thermal stress forming is a flexible forming process that forms sheet metal by means of stresses induced by external heat instead of by means of external force. Based on the analyzing of the influence of temperature on the thermal and mechanical properties of the materials, a 3D thermal-mechanical coupling model of laser thermal stress forming of thin steel sheet is set up in this paper. Based on ANSYS APDL developing platform, the stress field, temperature field and deformation field are obtained by numerical simulation of laser scanning of Q235 mild steel sheet for one time. Moreover, the forming progress and mechanism have been analyzed. The results show that the laser thermal stress forming is a quasi-steady-state process and its forming mechanism belongs to temperature gradient mechanism.

Thermal Stress Analysis of Fiber Wrapped High-Pressure Hydrogen Vessel

2014 ◽  
Vol 953-954 ◽  
pp. 1459-1462
Author(s):  
Hai Yan Bie ◽  
Meng Zhu Yang
Keyword(s):  
High Pressure ◽  
Thermal Stress ◽  
Stress Distribution ◽  
Stress Analysis ◽  
Thermal Loads ◽  
Mechanical Loads ◽  
Thermal Stress Analysis ◽  
Mechanical Coupling ◽  
Thermal Stress Distribution ◽  
Pressure Hydrogen

In order to reveal the influence of thermal on the stress distribution of fiber wrapped high-pressure hydrogen vessel, the strain and stress of the vessel in pure mechanical loads are studied firstly. Then thermal loads are taken into account, and the thermal stress distribution is given out. The results show that, the stress of the vessel liner changes little when the loads differ from pure mechanical loads to thermal mechanical coupling loads. While in the fiber-wrapped layer, stresses change significantly, and are non-monotonic. In addition, the deformation of the vessel decreases under thermal mechanical coupling loads.

Finite Element Analysis of Thermal Stress Distribution in Planar SOFC

2019 ◽  
Vol 7 (1) ◽  
pp. 1977-1986 ◽  
Author(s):  
Chih-Kuang Lin ◽  
Tsung-Ting Chen ◽  
An-Shin Chen ◽  
Yau-Pin Chyou ◽  
Lieh-Kwang Chiang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Stress ◽  
Stress Distribution ◽  
Element Analysis ◽  
Thermal Stress Distribution

THE EFFECTS OF ELASTIC STIFFENING ON THE EVOLUTION OF THE STRESS FIELD WITHIN A SPHERICAL ELECTRODE PARTICLE OF LITHIUM-ION BATTERIES

2013 ◽  
Vol 05 (04) ◽  
pp. 1350040 ◽  
Author(s):  
WENBIN ZHOU ◽  
FENG HAO ◽  
DAINING FANG
Keyword(s):  
Stress Field ◽  
Lithium Ion Batteries ◽  
Internal Stress ◽  
Concentration Gradient ◽  
Concentration Field ◽  
Lithium Ion ◽  
Coupling Model ◽  
Ion Concentration ◽  
Hysteresis Phenomenon ◽  
Mechanical Coupling

Poor cyclic performance of lithium-ion batteries is calling for efforts to study its capacity attenuation mechanism. The internal stress field produced in the lithium-ion battery during its charging and discharging process is a major factor for its capacity attenuation, research on it appears especially important. We established an electrochemical –mechanical coupling model with the consideration of the influence of elastic stiffening on diffusion for graphite anode materials. The results show that the inner stress field strongly depends on the lithium-ion concentration field, greater concentration gradients lead to greater stresses. The evolution of the stress field is similar to that of the concentration gradient but lags behind it, which shows hysteresis phenomenon. Elastic stiffening can lower the concentration gradient and increase elastic modulus, which are two major factors influencing the inner stress field. We conclude that the latter is more dominant compared to the former, and elastic stiffening acts to increasing the internal stress.

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