Design, fabrication and measurement of a microchannel heat sink with a pin-fin array and optimal inlet position for alleviating the hot spot effect

摘要

A microchannel heat sink with an inlet near the midpoint of the diagonal and high aspect ratio micro pin-fin array was designed, fabricated and measured. The heat transfer performance of the microchannel heat sink was simulated by a computational fluid dynamics (CFD) method. The inlet near the midpoint of the diagonal was proposed to alleviate the hot spot effect. The maximum temperature of the chip was reduced by up to 26.7% at a dissipation power of 72W compared with other reference inlet/outlet configurations. Other parameters of the micro pin fins, such as the height, the spacing distance and the edge length, were optimized for improving heat transfer capacity. The microchannel heat sink prototype sample was fabricated and tested through UV-LIGA technology and an infrared thermal imaging system, respectively. The convective heat transfer increased at high flow rates (40ml min~(-1)～90ml min~(-1)), which resulted in a gradually increasing deviation between simulation and experiment. The measurement results show that the maximum dissipation heat flux can reach 209W cm~(-2) when the chip maximum temperature is under 85℃ at a flow rate of 90 ml min~(-1). It is shown that the optimization of inlet position and micro pin-fin geometrical topology give the microchannel heat sink the potential to remove high heat flux.