Examining performance of microchannel cold plate heat sink from its three parts along coolant flow direction and new structure designs based on the new considerations

The microchannel cold plate heat sink is a very compact heat exchanger with higher ratios of heat transfer area to volume and is widely used in the field of active cooling of electronic devices with high heat flux. A variety of structural forms have been proposed and a huge amount of studies, both experimental and numerical, have been conducted. It can be broadly divided into single-layer structure and double-layer structure, of which the single-layer structure is more widely used. This article first discusses the geometric structure classification method of the single-layer microchannel cold plate heat sink. Along the cooling medium flow direction of the cold plate, there are three indispensable subsequent parts: inlet/outlet, manifold, and microchannel. It is because of the differences in the three parts, a variety of cold plates are formed. A classification method according to the three major parts is proposed. Summarizes of the existing forms of each part have been made and their major flow and heat transfer characteristics have been commented. Taking the three parts as three variables many levels are selected. By using the orthogonal experiment design of the Taguchi method, 26 new structural designs of the microchannel cold plate heat sink are provided. Numerical simulations of the heat transfer and flow resistance for the 26 newly designed cold plates are conducted and performance comparisons between them are provided. TOPSIS method is used to evaluate the comprehensive performance of different designs. Experiment validation for numerical results is conducted for No.20 cold plate. Finally, the cold plate design is further improved to increase the heat flux to 266.60 W/cm², with the ratio of q/Δp being 14.08 W/cm⁻²·kPa⁻¹, superior to most existing similar cold plate.