Heat Switch to Control the Local Thermal Resistance Using Liquid Pillar Control

Abstract

This paper presents the heat switch for electronic package to be operated at room temperature. The heat switch controls the thermal resistance between two objective plates using liquid pillar. By forming the liquid pillar, the temperature of the specific area can be controlled locally. In order to realize the desired switch operation, the heat switch should be provided with reservoir, switching channel and breathing channel. The channels are carefully designed to control the liquid pillar precisely. The liquid pillar formation depends on the liquid contact angle. The designed channel geometry can generate hydrophobic surface by using suddenly diverging shape like as capillary stop valve. Thus, the liquid pillar can be created at desired point with high stability. To verify the switch operation, the switch panel was designed and experiments were performed on a designed switch for the liquid pillar control and the heat flow regulation. The experiments show that the heat switch is able to work properly. Also, the temperature distribution and thermal resistance was changed in accordance with channel state as desired. As a result, the heat switch can be a good candidate of thermal management in the commercial electronics packages.