Extreme hotspot heat flux thermal management via thin-film evaporation from microstructured surfaces

Abstract

We demonstrate an extreme heat flux thermal management solution targeted towards cooling hotspots with 640×620 μm2 footprint. Our heat dissipation strategy utilizes thin-film evaporation by incorporating micropillar wicks that allow passive fluidic transport via capillarity in addition to maximizing the evaporation area by extending the three-phase contact line. With our wick design, we dissipated ≈5.8 kW/cm2, the largest heat flux reported to date when compared to past thin-film evaporation studies with similar size hotspots. Our experimental results indicate that thin-film evaporation is a promising thermal management strategy for the next generation microprocessors, power amplifiers and radio-frequency devices, where cooling hotspots is a significant challenge.