SUMMARY

The rapid growth of electrified transportation has escalated power density demands, pushing for the replacement of traditional silicon-based power electronics packages with wide-bandgap semiconductor devices, especially SiC, due to their highly desirable electrical characteristics. However, existing integration platforms designed for Si have hindered the full realization of these device-level benefits. To address this challenge, this study proposes a novel packaging approach with integrated cooling, employing multi-functional coolers that serve both electrical and thermal functions. Starting from the computation of switching and conduction electrical losses in a half-bridge circuit of a 50 kW SiC-based drive inverter with pulse width modulation, the multi-physics performance of the proposed package is evaluated against a standard power card, with a focus on electrothermal challenges, thermomechanical reliability, and thermohydraulic characteristics. For the analysis of thermohydraulic performance, a single-phase cooling loop is established, utilizing optimal designs that have been additively manufactured and characterized through X-ray analysis, Shadow-Moiré techniques, and laser surface profilometry. Recognizing the limitations of micro-pillar-based single phase liquid cold plates, a hybrid cooler, combining micro pin fins with TPMS structures is proposed to strategically improve the cooling performance near active devices, without compromising on pumping power. Despite the improved thermal performance due to local fluid mixing, further increase in power density levels and reduction in chip sizes necessitate the use of improved heat spreading, leading to a unique, two-level cooling system, combining a vapor chamber and cold plate. Considering the dominant role of boiling limit in miniaturized vapor chambers, flow visualization experiments are designed to investigate two-phase phenomena within vapor chambers and predict heat transfer performance limits.