Ultra-thermostable embedded liquid cooling in SiC 3D packaging power modules of electric vehicles

Abstract

As the enhanced acceleration performance of electric vehicles demands improved mileage capabilities, 3D packaging is a promising solution for developing high-power-density SiC power modules. However, 3D packaging causes instability owing to the increased heat flux and heat dissipation inside the power module. Thus, this paper proposes an ultra-thermostable embedded liquid cooling strategy for the thermal management of SiC 3D packaging power modules in electric vehicles. We constructed an embedded micro pin–fin (E-MPF) with non-uniform density in the SiC substrate to mount the SiC Schottky barrier diodes (SBDs). The thermostability and temperature uniformity of the SiC 3D packaging power modules containing E-MPF SiC and direct bond copper (DBC) substrates were verified. The results revealed that the SiC SBDs mounted on the E-MPF SiC substrate could stably operate up to a total power dissipation of 320 W at a 100 mL/min coolant (water) flow rate, whereas those attached on the DBC substrate could be operated only under 144 W (operation terminated at a maximum junction temperature of 175 ℃). Furthermore, the junction-to-coolant thermal resistance of the E-MPF SiC substrate could be reduced by 78.89 % compared to that of the DBC substrate. Moreover, the prepared 3D stacking package effectively improved the temperature uniformity of the SiC power modules by 68.69 %. The presented ultra-thermostable E-MPF substrate SiC power module can steadily render a motor torque elevation that is one magnitude greater than that required for sustaining the boiling-free condition on the DBC substrate. This embedded liquid-cooling architecture affords a feasible solution for the thermal management of upcoming high-power electric vehicle SiC inverters.