Analysis of the Thermo-mechanical Performance of Double-Sided Cooled Power Modules

Double-sided cooled (DSC) power semiconductor modules have garnered increased interest over the past decade due to their ability to offer an additional path for heat removal, facilitating higher power density operation while reducing junction temperatures and thermal stresses. Nevertheless, when operating at similar junction temperatures, DSC modules might exhibit elevated thermo-mechanical stress compared to single-sided cooled (SSC) modules. This increase can be attributed to restricted vertical movement within the DSC modules. Furthermore, the integration of various spacers within the DSC modules, which enable bond wire connections to gate terminals, can significantly influence both the thermal performance and induced thermo-mechanical stresses. Depending on the materials used in the spacer, the thermal performance and thermo-mechanical stresses inside the module can vary. In this study, we have first analysed the thermal performance of the DSC power modules employing different spacers. Following that, we have also performed thermo-mechanical analysis in different solder layers. Finally, fatigue analysis is done to demonstrate the weakest solder layer inside the package.