Failure analysis and simulation of IGBT under active and passive thermal cycling

This paper discusses the fatigue failure mechanisms associated with the packaging of Insulated Gate Bipolar Transistors (IGBTs) and investigates the failure behavior of aluminum wires and die-attached solder layers within IGBTs. The study utilizes an electro-thermal-mechanical finite element model, temperature shock tests, and power cycle tests. Using finite element analysis with COMSOL Multiphysics software, the failure process of aluminum wires and solder layers in IGBT power modules was simulated, and the temperature and stress distribution of the devices during the power cycle were determined. The Anand model was employed to analyze the creep mechanism of the solder layer. Through Electron Backscatter Diffraction (EBSD) analysis, the macroscopic failure behavior was correlated with the microstructure, revealing the grain size and grain boundary evolution in the crack tip region during the crack propagation of the Al bonding wires. The research aims to enhance the understanding of fatigue failure mechanisms and improve the reliability of IGBT devices.