Air-cooled hybrid vapor chamber for thermal management of power electronics

Vapor chambers (VC) are passive heat spreaders that dissipate localized heat by distributing their working liquid's latent heat in efficient ways, and in turn, promoting device performance. In this study, the role of the physicochemical characteristics of the condenser side of a VC using a wick-free uniformly hydrophobic surface versus a wettability-patterned surface opposing a wick-lined copper evaporator is investigated. The device's cooling capacity with water as working fluid is evaluated via two silicon-based metal-oxide- semiconductor field-effect transistors (MOSFET) as heat sources and an air-cooling mechanism simulating a real-world application in power electronics. The results show that both VC types with wickless condensers outperform a solid copper plate at high heat fluxes. A maximum heat removal of 202 W was achieved via a wettability-engineered condenser with a minimum thermal resistance below 0.01 K/W.