Thermal Management of Two-Sided Heat Load on a Cold Plate Considering the Friction Stir Welding Process

Friction Stir Welding (FSW), known as solid-state welding, is a suitable cost-efficient production technique as the number of cold plates is high and the time allocated for the mass production is limited. After it is discovered in 1991 by The Welding Institute (TWI) of the United Kingdom, Friction Stir Welding (FWS) in general, is the mostly preferred production technique as the heat loads are located on one side of the plate and the shape of the channel is usually simple. However, the two-sided heat sources case became a very common application in electronic cooling to obtain compact design especially for Active Phased Array Radar Antenna in aviation platform resulting in a complex cold plate design. In this study, some thermal and structural problems with identical two-sided high heat flux on a cold plate are discussed with the application of both FSW and Vacuum Brazing (VBR) techniques. In addition, solution alternatives are evaluated and supported with CFD analysis. Since the size, weight, and power (SWaP) are essential to have a compact and efficient solution, it is crucial to make an optimization depending on the Re number to keep the pressure drop as low as possible providing efficient cooling as well. The present study focuses on different heat sink designs and positioning affecting the cold plate overall design and discusses the advantages and disadvantages by considering the cooling requirement and mechanical design as the product is made with FSW.