Thermal performance of ultra-thin vapor chamber with etched micro-structure for electronics cooling

Abstract

As a two-phase heat transfer element, vapor chambers (VCs) have received widespread attention in recent years due to the advantages of high-effective thermal conductivity, lightweight, and flexibility in design and application. With the development of microelectronic products towards higher levels of integration and compactness, there is also a growing demand for thinner VCs. In this paper, the heat transfer performance of novel ultra-thin vapor chambers (UTVCs) with a thickness of only 0.3 mm was designed and tested. The composite wick is made of an etched micro-structure and 300 in−1 copper mesh. The heat transfer performance of UTVCs such as the temperature distribution, the temperature difference and the thermal resistance was investigated under different heating power by evaluating the effect of etched micro-structures, liquid charging ratio and test direction. The results of the experiment showed that the optimal liquid charging ratio for continuous micro-structure and non-continuous micro-structure is 60 % and 80 %, respectively, and the minimum temperature difference is 1.3 °C and 3.5 °C for the heating power of 5.5 W, respectively. In addition, the continuous micro-structure UTVC with a liquid charging ratio of 60 % has better heat transfer performance and the maximum temperature difference is less than 5 °C in all test directions of horizontal direction, gravity direction and anti-gravity direction.