Fabrication of an electrostatically actuated impingement cooling device

摘要

This paper reports on the fabrication and characterization of an electrostatically actuated liquid droplet,impingement cooling device. The continuous increase of IC power density and the widespread use of 3D integrationcall for advanced cooling techniques. These are necessary to keep the device temperature low and to improve thereliability. Here we propose a 3D cooling device in which droplets are electrostatically actuated through verticalchannels and impinge on an IC surface. The channels are formed by stacking thinned perforated silicon dice. Bymeans of DRIE, vias with diameters ranging from 100 μm to 300 μm are etched into a low resistivity 200 mmsilicon wafer. Further processing involves passivation with oxide, contact opening, bonding to a carrier wafer andgrinding. Finally, stacking of the dies is achieved by debonding individual dies from the carrier wafer and bondingthe first die to a silicon base. A second die is then aligned and bonded on top of the first one, and this operation isrepeated a third and fourth time so as to create a “tower of Hanoi” structure. The preliminary results on the electrowetting properties of this device are reported.