Miniature Liquid Cold-plate Enabled by Metal Spraying: A Thermal Management Solution for a Modular 1 kW Bi-directional GaN-based dc-ac Converter

In recent years, power electronic systems have been consistently required to achieve higher power while also minimizing footprint. Addressing these demands has produced new electro-thermal challenges within these highly coupled systems. This work utilizes metal spraying techniques to fabricate a custom miniature liquid cold-plate to cool a 1 kW high-frequency bi-directional GaN-based dc-ac converter. A commercially sourced ‘off-the-shelf’ cold-plate, comprised of a serpentine copper tube embedded in an aluminum block and buried in low thermal conductivity epoxy is used as a baseline to compare the thermal performance of the proposed cold-plate. Experimental results show that the metal sprayed cold-plate yields lower junction temperatures at the same flow rate while also decreasing volume and mass when compared to the off-the-shelf system.