Study on Easily-aging Parts of Solder Layer in IGBT Module

As the most important part of the traction converter, the IGBT power device is almost indispensable in emerging fields such as smart grids, electric vehicles, and new energy power generation. When the converter is working, the IGBT module is often subjected to strong thermal power. Due to the stepped arrangement of module packaging and different thermal expansion coefficients of internal materials, the thermal stress exerted on the module parts will be imbalanced, so the solder layer is prone to thermal aging, thus threatening the operational safety of the power electronic system. Taking the reliability of IGBT as a starting point, this report sets the electric-thermal-mechanical multi-physical field coupling model of IGBT in COMSOL and obtains the temperature and thermal stress characteristics of the solder layer under different power conditions of IGBT. By studying the simulation results of two thermal power loss circumstances, the parts of the solder layer that are prone to aging are summarized to identify the aging state of the module. This is conducive to the stable operation of the power electronic system.