Reliability evaluation for specify factor of fatigue on power device

This paper presents a fundamental method to evaluate thermal fatigue life of power module. Coupled electrical-thermal analysis is performed to obtain the distribution of temperature due to electric current. Then, thermo-mechanical analysis is carried out to calculate inelastic, aluminum wire bonding was done. Crack path simulation technique was used to evaluate total fatigue life of solder joint and resultant temperature increase. The fatigue life of aluminum wire bonding was estimated by the same model and similar approach. The crack at the center of the solder layer below aluminum wire bonding. The the maximum temperature in the solder grows up of crack propagation. Therefore, the fatigue life of aluminum wire bonding deteriorates. That is to say, this study is comparison between the fatigue life of solder joint and aluminum wire bonding for evaluate total life of the power module.