Air Cooling of Power Electronics Through Vertically Enhanced Manifold Microchannel Systems (VEMMS)

Abstract

Abstract To improve the reliability and efficiency of power electronics, their thermal management must be further enhanced. Next-generation electronics systems are predicted to dissipate more heat as die size shrinks and power levels increase. Traditional air-cooling approaches usually provide insufficient performance or require heavy and bulky heat sinks to achieve adequate thermal management. To address this problem, a novel air cooled vertically enhanced manifold microchannel system (VEMMS) was developed. While minimizing the footprint required on the printed circuit board, the system offers efficient thermal management in a conformal scheme that accommodates the associated power electronics and their electrical connections. This work describes the manufacturing process of the air-cooled VEMMS heat sink and its experimental characterization and thermo-fluidic performance. Good agreement was obtained between the test results and numerical predictions. Using air at ambient conditions, thermal resistance of 2.6 K/W was achieved with a single-sided cooling architecture with a <1.5 cm2 footprint and <2 cm3 total heat sink volume. A full-bridge electrical power density of ∼84 kWe/L and overall direct current (DC–DC) converter power density of ∼20 kWe/L were achieved at reasonable flow rates and pressure drops using commercially available miniature electric fans.