Performance of a MEMS based micro capillary pumped loop for chip-level temperature control

Abstract

To provide direct cooling to electronics and microelectromechanical systems, a three port micro-capillary pumped loop (CPL) was designed, fabricated and tested using current MEMS technology. The two wafer design consists of a silicon and a borofloat glass wafer. An evaporator, condenser, reservoir, and liquid and vapor lines were etched into the silicon wafer, while the glass wafer serves as a cover plate into which grooves were etched for capillary pumping. The geometry of the components of the device were determined via an analytical study. A finished device was run near steady state using laser spot heating and water as the working fluid. It was determined that a 1 mm/spl times/2 mm evaporator operates at a constant 100 /spl deg/C until wick dry-out at a laser power of 7.5 W (+/-2 W). Furthermore, with the same laser power the micro-CPL resulted in a backside cooling of at least 7 degrees C.