Abstract
In this paper, we proposed a sealing method of a degassed working fluid for a micro thermal diode. The micro thermal diode is one of the key components of a micro thermal device such as a micro refrigerator and a thermal energy harvester. A working fluid, which transfers heat energy by evaporation and condensation like a vapor chamber, is encapsulated in a cavity of the thermal diode. The working fluid is driven by wettability difference of condensation and evaporation parts, which makes a one-way fluid circulation. To work the thermal diode properly, non-condensable gas such as air should not be included in the cavity. Therefore, a fluid insertion method without mixing the non-condensable gas is proposed. The non-condensable gas in the device was removed by in situ freeze-degassing method and the working fluid was sealed by using gold-bump crushing method. The working fluid was successfully sealed and the pressure in the cavity was kept for more than 600 hours.
