An Experimental Study of Slot-Jet Impingement and Mist Cooling of Microprocessors

This paper describes an experimental study of air slot-impingement and mist cooling of microchannels fabricated on the back of a silicon chip. A rig was designed and fabricated for the experimental study. The test section consisted of a 21 mm times 21 mm square silicon die with 100 mum-wide microchannels etched on its back surface, which were covered with a glass plate to confine the flow through the microchannels. A slot was machined across the glass cover plate to admit air from an inlet manifold. The performance of an air-water mist spray cooling system was also studied experimentally. It was found that an air-water mist spray cooling system can give a higher cooling rate than air-only slot-impingement cooling of microchannels. For the same heat dissipation, it was found that the air-water mist spray cooling system required a much smaller flow rate of air. Comparing with data available in the literature, it was also found that mist cooling of microchannels was much more effective than on plane surfaces