Impact of thermal interface material on power cycling lifetime of IGBT module

In the DC power cycling test of standard IGBT power modules, cooling conditions include but are not limited to the coolants' type, temperature and flow rate as well as the type and thickness of thermal interface materials (TIM). The cooling conditions may have an impact on the entire process of the test. At present, few papers report this aspect. In this paper, different kinds and thickness of the TIM are used to change the cooling conditions, which are quantitatively characterized by the cooling time (toff). The impact of the TIM on power cycling lifetime of IGBT module is studied. The results show that when the toff becomes longer, the power cycling lifetime of IGBT module will improve. A thermal-mechanical co-simulation is carried out to further study the failure mechanism behind for the IGBT under different cooling conditions.