Investigation of Thermal Performance in Pin-fin Baseplate for High-Density SiC Power Modules

With rising power density in e-mobility Silicon Carbide (SiC) modules, effective thermal management has become critical for power electronics performance and reliability. Liquid-cooling SiC modules commonly use pin-fin baseplates with ceramic substrates. Optimizing pin-fin structures offers a cost-effective way to enhance chip-coolant heat transfer for improved thermal management. This paper investigated the geometrical effects of the pin-fin baseplate on the liquid cooling capability through numerical simulations. A thermal-fluid coupling model was first established in COMSOL Multiphysics and verified against experimental data. By changing the shape and dimensions of the pin-fins, junction-to-fluid thermal resistance and pressure drop were evaluated. Among the circular, elliptical, diamond-shaped and conical pin-fins, the elliptical pin-fins exhibited the best liquid cooling performance, achieving a 12.1% reduction of thermal resistance compared to diamond-shaped designs under a typical pressure drop of around 10 kPa. To reveal the physical mechanism behind, Computational Fluid Dynamics (CFD) analysis was performed with the simplified geometrical model and the results showed the elliptical profile's aerodynamic shape effectively reduces the wake formation and pressure drop, while the diamond-shaped pin-fins suffered from the flow separation due to their sharp edges. Circular and conical shaped demonstrated intermediate thermal and hydraulic performances. The elliptical configuration proved to be effective for high density SiC power modules where thermal management and pressure drop must be carefully balanced. To summarize, this paper investigated the liquid cooling capability of different pin-fins in the baseplate and further revealed how the pin-fin geometry significantly impacts both heat exchange efficiency and fluid flow behavior in the cooling system.