Combined finned microgap with dedicated extreme-microgap hotspot flow for high performance thermal management

Abstract

There are a number of emerging electronic applications that are thermally limited and may exhibit high overall power dissipation (“background”) combined with local very high power fluxes (“hotspot”). We have batch fabricated a microfluidic heat sink specifically designed to address both levels of heat removal. A microgap for hotspot cooling and micropin-fins are sequentially deep etched in a silicon substrate. The combined microfluidic heat sink is sealed by bonding another layer of silicon to the substrate. The coolant is injected into the combined heat sink from two distinct ports to dissipate the generated heat by micro-heaters. These micro-heaters emulate hotspot and background heat generation by active circuits as well as enable chip junction temperature measurement. Mechanical modeling is conducted to verify the reliability of the design and assess limits on the operating pressure of the fabricated system.