Semi-porous-fin microchannel heat sinks for enhanced micro-electronics cooling

With their ability to provide substantial solid-fluid interfacial areas, porous-fin microchannels emerge as a promising solution for the thermal management of upcoming microelectronic chips. Previous investigations have substantiated the enhanced hydrodynamic performance of porous-fin microchannels compared to their solid-fin counterparts. Nevertheless, it has been found that porous fins can diminish the thermal performance of straight plate-fin microchannel heat sinks at high channel heights due to their reduced effective thermal conductivity. In this paper, semi-porous fins that replace a portion of a solid fin height with a metallic porous fin are proposed as an alternative approach to concurrently improve the thermal and hydraulic performances of microchannel heat sinks. The effect of the porous height ratio, defined as the porous fin height to the overall fin height, on the thermo-hydraulic performances of semi-porous-fin microchannel heat sinks is examined. Results revealed that the thermal resistance decreases with an increase in the porous height ratio, reaching its lowest value at a ratio of 0.5. Beyond this point, a further increase in the porous height ratio results in an increase in the thermal resistance compared to an all-solid fin design. In other words, there exists a critical porous height ratio below which the thermal resistance of the semi-porous-fin microchannels is lower than that of the solid-fin microchannel. The semi-porous-fin microchannels have up to 11.12% lower thermal resistance compared to the solid-fin microchannel. Additionally, increasing the porous height ratio decreases the pressure drop penalty across all considered operating conditions. This research reveals that semi-porous fin structures could offer new pathways to improve the cooling performance of high-power electronic chips.