Failure Mechanism Analysis of Bond Wire of High Power IGBT under Different Load Current

By means of finite element simulation, the power cycling test of as submodule of a 3300V/1500A IGBT module is simulated. The influence of different current and turn-on time combinations on the diffusion of temperature is studied, and the power cycling lifetime of the bond wire is calculated by Coffin-Mason model. The simulation results show that the IGBT power cycling with the same junction temperature fluctuation and highest junction temperature, and the maximum surface temperature of IGBT chip under large current with short turn-on time is much higher than that of IGBT chip under low current with long turn-on time, shows a larger temperature gradient, which leads to the failure of the bond wire more easily for high power IGBT. This paper can provide guidance for the lifetime prediction and aging mechanism of the high power IGBT module.