Fabrication of a silicon-carbide micro-capillary pumped loop for cooling high power devices

This paper reports on the fabrication of a silicon carbide (SiC) micro-capillary pumped loop thermal management system. The micro-capillary pumped loop was fabricated using a two wafer design from SiC and glass substrates. The evaporator, condenser, and connecting lines were etched into the silicon carbide wafer and are 150 microns deep with vertical sidewalls. Capillary wicking grooves were dry-etched into borosilicate glass and are 30 microns deep and 6-30 microns wide with trapezoidal sidewalls. Glass was selected for the capillary grooves wafer in order to provide optical access of the micro-capillary pumped loop performance during testing and evaluation. The footprint of the micro-CPL device is approximately 13 mm×30 mm.