Kinetic Cooling for thermal management of high power electronics

Abstract

Fan-cooled heat sinks are the most widely used active-cooling solution in the electronics industry. The cooling architecture uses two principal components: a finned heat sink to spread heat from heat-generating components across a large surface area and an air mover (e.g., fan or blower) to blow cooling air past the heat-sink fins. The resulting architecture typically uses an air mover that occupies a significant portion of the overall cooler volume, quite often over 50% of the cooling volume. Although generally acceptable when there is sufficient space available for the cooling solution, fan-sinks that use large air movers are not suitable for space-constrained applications. Kinetic Cooling seeks to address this limitation of traditional fan-cooled heat sinks by making the air mover thermally conductive and integrating it into the heat transfer path. In Kinetic Cooling, an additional heat-transfer path is introduced: a portion of the heat is transferred into a rotating heat-sink impeller, which acts as both a heat sink and an air mover. The rotating metallic blades of the heat-sink impeller generate cooling airflow, which cools both the rotating blades as well as stationary fins used elsewhere in the cooler. The ratio of heat-transfer surface area to overall cooler volume can be increased as much as 2X compared to the traditional fan-cooled heat sinks by including the air mover into the heat-transfer path. By being able to achieve a lower thermal resistance at a given cooler volume and airflow, Kinetic Cooling provides favorable tradeoffs between three critical performance variables: thermal resistance, acoustics, and overall cooler size.