Thermal performance of micro-structured evaporation surfaces-application to cooling of high flux microelectronics

An experimental investigation on characterization of copper-finned micro-grooved surfaces for effective evaporation heat transfer with applications to cooling of high flux electronics was conducted in the present study. Performance of the copper-finned microstructures were studied as a function of operating parametric values of fin density, fin height, fin length, and channel width over a surface which was rosin soldered to a 10 mm × 10 mm heating block (typical size of an electronic chip). The performance of the copper-finned microstructures versus a flat/smooth nichrome plate in HFE-7100 was significantly higher. Two experimental conditions were investigated. In the first set of experiments pool boiling over the groves was examined, where as in the second set of experiments the fluid was forced-fed into the grooves in a forced convection mode. It is shown that the forced fed mode yields higher heat transfer coefficients than the submerged/pool boiling mode. In general the micro-grooved surfaces performed at least three times better than the flat/smooth surface and preliminary results with the forced-fed evaporation experiments suggest that an order of magnitude heat transfer coefficients are possible when compared with a smooth surface.