A Double-Sided Cooling SiC Power Module with Pressure Contact Packaging

Pressure contact technology (PCT) in power modules offers advantages in improved thermo-mechanical performance and double-sided cooling. This work presents the design and implementation of a proposed PCT in a half-bridge SiC active metal brazed (AMB)-based module. The 3D layout of the power loop provides external degrees of freedom to minimize the commutation loop inductance and to balance the current. To accommodate the small footprint of SiC MOSFETs, graphene films (GFs) and fuzz buttons are applied for the source/drain connectors and gate pins, respectively. These soft connectors not only conduct current and heat but also absorb a certain amount of thermal stress. A thermo-mechanical coupled model under fluid cooling condition is developed to precisely compare the performance of the modules fabricated both with Molybdenum (Mo) and GF connectors. The implementation of GFs significantly reduces the junction temperature and balances the stress of the chips. The double-sided cooling reduces the measured junction to heatsink thermal resistance of the experimental prototype with GF to 0.68 K/W. The double pulse test of the prototype demonstrates a low parasitic inductance of 5.1 nH and a voltage overshoot of only 5.8 %.