On the Potential of Galinstan-Based Minichannel and Minigap Cooling

Galinstan, a gallium, indium, and tin eutectic, may be exploited for enhanced cooling of microelectronics because of its favorable thermophysical properties. A careful evaluation of its cooling potential, however, has not been undertaken. Provided here is a first-order model to compute the total (i.e., caloric plus conjugate conduction and convection) thermal resistance of galinstan-based heat sinks. Geometrically optimized minichannel heat sinks with rectangular channels for surface area enhancement and minigap, i.e., single parallel-plate channel, heat sinks are considered. Direct liquid cooling of a microprocessor die is envisioned. Therefore, the flow channels within the heat sinks are 302- μm tall, the pressure drop prescribed across them is 214 kPa, and their streamwise length is varied from 5 to 20 mm. The calculations suggest that galinstan is a better coolant than water in such configurations, reducing thermal resistance by about 40%.