Investigation of Microporous Coatings and Mesoscale Evaporator Enhancements for Two-Phase Cooling of Electronic Components

Abstract

An empirical study of pool nucleate boiling enhanced with a microporous coating was conducted within the context of microprocessor cooling. A thermal test vehicle (TTV) emulated the heat load from a general purpose microprocessor and delivered a moderately nonuniform heat flux density distribution at the boiling surface that would be typical of mainstream microprocessors. The TTV was affixed to a copper test coupon that formed the bottom surface of a sealed boiling chamber containing FC-72 at atmospheric pressure. A design of experiments was conducted on multiple test coupons to identify how the microporous coating, the base thickness of the coupon, and the height of small pin fins affect the combined conduction and boiling heat transfer from the test coupon. The data revealed that the presence of the microporous coating was the most significant factor of the three tested and indicates that the presence of fins as short as 0.5mm may play a role in reducing hysteresis in the boiling curve.