Highly thermally conductive and electrically insulated ceramic heat pipes based on powder-sintered glass capillary wick

Abstract

Electronic devices with high heat flux are increasingly demanding on both highly thermally conductive and electrically insulated technology. However, electrical insulation and thermal conduction are contradictory properties, making the development of technology that satisfies both an ongoing research challenge. In this study, a novel highly thermally conductive and electrically insulated ceramic heat pipe (CHP) is developed to solve this dilemma. The insulating wick of CHP consists of sintered irregular glass powders. The microscopic morphology and wettability of the insulating wicks on the capillarity were investigated in detail. Meanwhile, the effects of filling rate (FR) and different working conditions on the performance of CHP were investigated. It is found that the 75 % FR CHP is recommended for low power (≤ 30 W) with thermal resistance down to 0.85 °C/W, while the 100 % and 125 % FR CHPs have more advantages in heat dissipation at high power. The 100 % FR CHP combines the advantages of thermal conductivity and thermal power, with a high thermal conductivity of 4021.18 W/(mK) at 65 W and a maximum thermal power of 70 W. Moreover, CHP has an ultra-high withstand voltage value (27.45 kV). The reliability of the CHP also passes helium leak detection and aging tests under extreme conditions of high-low temperatures. The novel CHP with excellent thermal conductivity, electrical insulation and reliability, is the optimal component for high-voltage electrical insulating devices cooling.