Modular Design for a Single-Phase Manifold Mini/Microchannel Cold Plate

Abstract

The present work is related to the design of a manifold mini/microchannel heat sink with high modularity and performance for electronics cooling, utilizing two well established (i.e., jet impingement and channel flow) cooling technologies. A manifold system with cylindrical connection tubes and tapered inserts is designed for uniform coolant distribution among different channels and easy manufacturing of the whole cooling device. The design of the insert provides freedom to manipulate the flow structure within each manifold section and balance the cooling performance and required pumping power for the cold plate. Due to the optimized tapered shape of the insert inlet branches, fluid flows more uniformly through the entire heat sink fin region leading to uniform heat sink base temperatures. Extending the design of the heat sink fin structure from the mini to microscale, and doubling of the number of insert inlet/outlet branches, results in an 80% increase in the cooling performance, from 30 kW/(m2 · K) to 54 kW/(m2 · K), with only a 0.94 kPa added pressure drop penalty. The present cold plate design also provides flexibility to assemble manifold sections in different configurations to reach different flow structures, and thus different cooling performance, without redesign. The details of the modular manifold and possible configurations of a cold plate comprising three manifold sections are shown herein. A conjugate flow and heat transfer three-dimensional (3D) numerical model is developed for each configuration of the cold plate to demonstrate the merits of each modular design. Parallel flow configurations are used to satisfy a uniform cooling requirement from each module, and it is shown that “U-shape” parallel flow “base” configuration cools the modules more uniformly than a “Z-shape” flow pattern due to intrinsic pressure distribution characteristics. A serial fluid flow configuration requires the minimum coolant flow rate with a gradually increasing device temperature along the flow direction. Two mixed (i.e., parallel + serial flow) configurations achieve either cooling performance similar to the U-shape configuration with slightly more than half of the coolant flow rate, or cooling of a specific module to a much lower temperature level. Generally speaking, the current cold plate design significantly extends its application to different situations with distinct cooling requirements.