A silicon-carbide micro-capillary pumped loop for cooling high power devices

As more high-power wide-bandgap devices are being utilized, the thermal management issues associated with these devices need to be resolved. High power devices dissipate excessive heat that must be cooled, but traditional cooling methods are insufficient to provide such a cooling means. Although using SiC allows higher operating temperatures, an upper temperature threshold still exists for high frequency devices. The package under study consists of a SiC high frequency power device whose junction temperature must not exceed a specified temperature, such as 150°C, 175°C, or 200°C, set by the particular device technology. The technical goal is to develop an innovative cooling concept providing less than 100°C temperature rise relative to the base plate. In the baseline configuration, a high power SiC device is mounted onto a shim or thermal spacer that is then mounted onto a cold plate. This paper evaluates a SiC microcapillary pumped loop thermal management system that is incorporated into the shim of the device, taking advantage of phase-change to increase the thermal conductivity of the system. The results of the modeling, fabrication, and testing of the thermal management system are discussed.