Numerical analysis of a liquid metal cooled mini channel heat sink with five different ceramic substrates

Abstract

Due to recent advancements in micro-electro-mechanical systems (MEMS), the requirements of extracting a huge heat flux from a small surface area is ever-increasing. The use of mini/microchannel heat sinks (MCHS) can contribute much to the cooling mechanisms of these MEMS. The improvements in mini/microchannel heat sinks are getting a lot of considerations recently for this reason. The improvements in the MCHS can be accelerated by the use of liquid metals as working fluids, as they possess excellent thermophysical properties. But using the liquid metals as coolants is still limited in the MCHS because of the possibilities of corrosions of the heat sink’s substrate as it is often made of metals. The possible solution to this challenge can be using non-metallic materials (like ceramic materials) as the substrate material for the heat sinks, which possess resistive properties to corrosions and good heat transport properties as well. In this paper, the thermal performance of a mini channel heat sink with five different substrate materials (aluminum nitride, beryllium oxide, hafnium diboride, titanium diboride, and zirconium diboride) and four different alloys of gallium as working fluid EGaInSn,EGaIn,GaInandGaSn are tested. The study also offers the effect of different geometry parameters of the rectangular channel on the overall performance of the heat sink. The thermal and hydraulic performance of the heat sink is analyzed by the 3D numerical model. The results are validated against data obtained from literature and theoretical correlations. It has been found that the heat sink made of aluminum nitride (AlN) shows superior performance than all other substrate materials. The optimum coolant material as found after the analysis is GaIn.