Development of a Thermal Switch Using the Channel Geometry Effect for Electronic Packages

This paper presents development of a thermal switch using the channel geometry effect for electronic packages operated via liquid conduction channel formation. The developed switch panel is composed of several conduction channels, breathing grooves, reservoirs, and actuators. On demand, a vacant conduction channel is filled with liquid supplied by an actuator and conducts heat from hot spots to cold. This result in increased heat dissipation. Through this switch operation, the temperature of the designated hot spot can be controlled locally. In order to realize the desired switch operation of liquid contact and separation properly, with liquid supplied from a reservoir and returning to the reservoir, the liquid column should be precisely controlled based on the channel design. The conduction channel has a burst area to achieve the precise liquid control. The burst area was geometrically designed to provide a hydrophilic surface by taking into account the burst pressure. In a series of experiments, the newly designed switch was shown in controlling the liquid column well. The results also showed that this thermal switch was able to regulate the heat flow and the temperature distribution locally through the achieved liquid column control.