Comparative Study of the Parasitic Capacitance of Dielectric-Liquid-Cooled Power Module Designs

Dielectric-liquid-cooled (DLC) power modules allow the direct liquid cooling of module bus bars and offer a promising option for high power density. In this work, the electric field distribution and parasitic capacitance of a typical DLC module design are investigated to study their implications on electrical performance. Finite element analysis (FEA) simulation results suggest that the parasitic capacitive coupling between the switching node and DC bus bars are significantly lower than that of conventional ceramic direct-bonded-copper (DBC) module with comparable geometry and ratings. FEAcircuit co-simulation results demonstrate the benefit of the DLC design for switching transient performance.