Numerical Investigation on the Thermal Resistance and Assembly Cost in SSC and DSC Power Modules

This paper explores the trade-off between thermal performances and assembly cost in state-of-the-art power modules (PMs) by means of extremely detailed 3-D FEM simulations carried out in COMSOL Multiphysics. The aim of the simulation campaign is to investigate the impact of design choices (e.g., thickness of layers, cooling systems efficiency) on the thermal resistance (RTH) of devices integrated in both single- and double-sided cooled PMs. The influence of thicknesses of copper and ceramic layers is explored, since they play a relevant role in defining thermal ratings as well as electrical and mechanical characteristics of the assemblies; generally, thicker layers improve mechanical ruggedness but may have impact on the PM electrical ruggedness through effects like partial discharge and dielectric breakdown. Finally, cooling solutions based on passive heatsinks and forced liquid systems are investigated.