Characterization of MEMS heat sinks having straight microchannels integrating square pin-fins for liquid cooling of microelectronic chips

Abstract

This work presents a liquid based MEMS (microelectromechanical systems) heat sink having straight microchannel integrating square pin-fins for cooling of microelectronic chips. Simulation based studies are carried out for evaluating the operation of this MEMS heat sink and the contribution of geometric features on its behavior. The behavior of the MEMS heat sink is calculated using pumping power and thermal resistance while the behavior of the flow passage is calculated based on of Poiseuille and Nusselt numbers. Investigations are done for Reynolds number ranging from 250 to 1500 when the MEMS heat sink is subjected to 1,000,000 W/m2. This study concludes that square pin-fins in the microchannel reduces the thermal resistance while raising the pumping power in comparison with microchannel without pin-fins. The decrease in the pitch of the square pin-fins results in increase in the pumping power and decrease in the thermal resistance. Moreover, it is identified that increase in the dimensions of the square pin-fins raise and reduce the pumping power and thermal resistance, respectively. The increase in the hydraulic diameter of the microchannel integrating square pin-fins results in lowering of both pumping power and thermal resistance. The Poiseuille and Nusselt numbers for different cases of straight microchannel integrating square pin-fins are quantified for the benefit of heat sink designers. Experiments are carried out in-house for generating data for purposes of validating the model.