MEMS Based Micro-Capillary Pumped Loop for Chip-Level Temperature Control

Utilizing current Micro Electro Mechanical Systems (MEMS) technologies, a three-port micro-capillary pumped loop (micro-CPL) was designed, fabricated and tested to provide integral cooling to electronics or MEMS type devices. The two wafer design consists of one silicon and one borofloat glass wafer. An analytical study, adopted from traditional CPL theory, was used in determining the geometry of the device, including the evaporator dimensions (1000 um x 2000 um) and the length of the liquid and vapor lines (35 mm). Using laser spot heating, the finished device was run near steady state. The micro-CPL resulted in a backside cooling effect of at least 7 K when a laser delivering 7.5 W (+/- 0.2 W) with a spot-size diameter of 1.0 mm was focused on the front side of the evaporator region.