Carol Gamlen

Development and testing of a planar, silicon mini-capillary pumped loop

A planar, silicon mini-capillary pumped loop (CPL) was designed, built, and tested using recent MEMS technology to provide integral cooling and temperature control for electronics. This design featured three silicon fusion bonded wafers incorporating an evaporator, condenser, liquid line and vapor line, all of which were dry plasma etched. Grooves were etched in the condenser and evaporator to provide passive capillary pumping. The finished device was bonded to an external reservoir via a through hole and was filled with a working fluid of water. The evaporator was bonded directly to an insulated gate bipolar transistor (IGBT) with a calorimeter epoxied above the condenser to control the temperature and monitor heat removal by the CPL. The mini-CPL was operated with an input heat load ranging from 3 to 10 W resulting in the junction temperature of the IGBT being reduced approximately 15 degrees Celsius from that of a solid Si substrate. The mini-CPL also performed as a thermal diode, turning on or off dep...