Thermal performance of copper vapor chamber with double-sided uniform radial micro-grooved wicks by laser fabrication

Abstract

In order to ensure the reliability of high heat-flux electronic devices, vapor chambers with double-sided uniform radial micro-grooved wicks (DURM) are developed. The driving force model of the working liquid inside the DURM vapor chamber is established. To enhance the driving force of the working liquid, the condensation micro-grooves and evaporation micro-grooves of the DURM vapor chamber are fabricated using an ultraviolet laser and an infrared laser, respectively. In addition, the startup characteristics and temperature uniformity of the DURM vapor chamber and the effect of the depth–width ratio and radiation angle of the micro-grooves and the filling ratio of the DURM vapor chamber on its thermal performance are also investigated. The results indicate that the DURM vapor chamber could maintain good temperature uniformity. Both the evaporation micro-grooved and condensation micro-grooved wicks facilitate the enhancement of the thermal performance of the vapor chamber. The double-sided micro-grooved wick with a larger depth–width ratio and a smaller radiation angle improves the thermal performance of the DURM vapor chamber. However, when the radiation angle is lower than 4°, further reducing the radiation angle has little effect on improving the thermal performance. In addition, an appropriate filling ratio helps reduce the thermal resistance of the vapor chamber under a certain heat load.