Micromesh-Enabled Low-Cost Thermal Ground Planes for High Heat Flux Power Electronics

SiC and GaN power electronic devices enable smaller die sizes and increase power densities with high heat fluxes ranging from 100 to 1,000 W/cm2, which calls for efficient thermal management solutions with matched ultra-thin form factors. Thermal ground plane is a vapor chamber fabricated using printed circuit board technologies. It is recognized as one of the most effective heat spreaders to dissipate high heat fluxes. Similar to heat pipes, thermal ground planes rely on self-sustaining capillary evaporation and condensation cycle. Nanostructures are being explored for improving such phase-change heat transfer devices; however, these nanoscale solutions are expensive and susceptible to reliability concerns. Here, we develop a low-cost and reliable thermal ground plane enabled by commercial copper micromesh wicking structures with enhanced capillary evaporation heat transfer, which can remove high heat fluxes, up to 425 W/cm2.