Hotspot Management by Holey Silicon-Metal Composites for 1 kW/cm2 and Beyond

Abstract

The trends toward high power, high frequency, and small-scale electronics are making thermal management ever more challenging. Passive cooling solutions simply based on high-thermal-conductivity materials or through-silicon vias (TSVs) are unable to meet the increasing demand for heat removal, especially for hotspots reaching 1 kWcm2 or beyond. Thermoelectric cooling (TEC) has attracted attention by offering solid-state active cooling, but the limited cooling performance and material compatibility have been the bottleneck. In this paper, we present a TSV-integrated TEC design based on holey silicon that provides hotspot management for thermal densities of 1 kW/cm2 and beyond while offering low power consumption, processing compatible, and scalable solutions. The TSV-integrated TEC design not only takes advantage of unique thermal conductivity anisotropy and efficient lateral TEC properties of holey silicon but also utilizes high cross-plane thermal conductivity of metals by creating a metal TSV right on top of the hotspot. Our numerical simulations of TSV-integrated TEC demonstrate exceptional cooling performance, which reduces a 1 kWcm−2 hotspot temperature from 153 °C to 68 °C while consuming 0.5 W for operation and the hotspot temperature is 67 °C lower than the same TEC design without TSV. We also explore possibilities of utilizing metal-filled holey silicon by modeling the electron-phonon coupling and size dependent transport phenomena, which can further reduce the off-state thermal resistance and improve the TEC performance depending on the metal-to-silicon boundary resistance. With holey silicon or metal-filled holey silicon substrates, the TSV -integrated TEC offers an efficient and effective hotspot thermal management solution for next-generation electronics.