Effects of temperature and pressure on interfacial thermal resistance of thermal interface materials in coupled heat transfer process with vapor chamber

The vapor chamber (VC) is commonly acknowledged as an effective solution for the dissipation of high heat flux hotspots, as it dissipates the localized heat over the entire surface. There is a prevailing emphasis on enhancing the thermal performance of the VC and decreasing its thermal resistance. However, little attention has been paid to the interface thermal resistance (ITR) between the heat source and the VC. In actuality, the ITR of the thermal interface material (TIM) is much greater than the thermal resistant of the VC. Further research on coupling test of heat transfer performance between TIM and VC needs to be carried out. As a consequence, a coupling test method of TIM and VC is put forward in this paper. The thermal performance of dissimilar TIMs was experimentally explored, including thermal grease, thermal phase change materials (PCMs), low-melting-point alloy (LMPA) and thermal pad, and their performance was compared to the situation without using TIM. The results indicate that utilizing PCM leads to an 87.5% decrease in ITR, while thermal grease results in a 51% decrease and LMPA leads to a decrease of 81%. The proper TIM is PCM, LMPA, thermal grease and thermal pad in descending order of effectiveness. The heat transfer performance of TIM is influenced by both temperature and pressure. In the practical applications of TIM, ensuring consistency is also essential, meaning the ITR of TIM should not be easily affected by various manual operations, in addition to considering the heat transfer performance.