Aging Failure Analysis of IGBT Module Solder Layer Based on Multi-physical Field Coupling

Insulated gate bipolar transistor (IGBT) is one of the most important devices in high power converter. Its reliability directly affects the stable operation of the whole system. During the operation of the converter, IGBT module is affected by various physical fields such as alternating current, heat, stress, etc., and the solder layer is easy to produce cavities and cracks, which will cause IGBT module failure. In this paper, the actual structure of IGBT is used for modeling, the thermal and stress multi physical field coupling simulation of the solder layer is carried out for the module, and the influence of the solder layer cavity and crack aging modes on the temperature and stress of the entire module is studied. The influence of the two aging modes on the module life is compared by the size of the thermal resistance. The results show that the cavity has a greater influence on the module heat dissipation, and the thermal resistance increases faster; The appearance of cracks will increase the module stress, and the cracks will expand from the periphery to the center, affecting the reliability of the entire module.