Fatigue Propagation Analysis of Crack Failure in High Power IGBT Solder Based on Multiphysics Coupling Model and XFEM

IGBT is one of the most important power modules in the electric traction converter system. In the long-term operation of the converter system, the IGBT module will suffer from alternating thermal load, frequent vibration impact and other coupling effects, which will easily lead to the cracking of the solder layer and the change of material properties, and the aging and damage of the accelerator parts. In this paper, the thermal-mechanical coupling finite element analysis model is established, and the influence of temperature on material properties is considered. The crack damage and periodic fatigue propagation behavior of solder layer are analyzed. Based on the damage mechanics theory and Paris equation, the fatigue propagation characteristics of IGBT solder layer crack element under periodic coupling stress are studied by using the extended finite element method, and the coupling effects of transient temperature change and vibration impact load on the dynamic crack propagation and damage aging evolution of IGBT solder layer under the change of material properties caused by temperature are considered.