Fourth Generation Aluminum Direct Water Cooling Structure with High Reliability for Automotive Electric System

Abstract:
To meet market demand on compactness and high power density, since the second generation direct water cooling modules, a closed-type cooler rather than an open-type cooler as used in our first generation modules has been employed to suppress thermal deformation. In the latest generation (fourth) structure reported in this paper, besides the optimization of coolant flow, fin-base thickness is further optimized to achieve both high cooling performance and high thermal cycling capability. The fin-base thickness and the height of the whole cooler are 1/5 and 1/2 of those in the first generation, respectively. The fourth generation products achieve 1.4 times higher thermal cycle capacity compared to the first generation products, despite the use of solder material with lower tensile strength than the first generation.