Preparation of Low-Cost and Low-Density Silicone Rubber-Based Thermal Interface Materials by Boron Nitride Oriented Synergistically with Alumina

Abstract

Electronic devices such as smart portable devices, drones and electric vehicles are in the process of rapid performance development, which puts higher demands on the thermal conductivity and density of thermal interface materials. These fields hope that under the premise of improving the thermal conductivity of thermal interface materials, the density can be kept unchanged or even reduced, so as to avoid the substantial increase in equipment quality caused by the use of more thermal interface materials. In this context, hexagonal boron nitride was used in conjunction with spherical alumina, and the hexagonal boron nitride was oriented in the through-plane direction through the traditional preparation process of a silicone rubber-based TIMs combined with clever post-processing. When the filling amount of hexagonal boron nitride is 7.2 wt.%, the composite has a through-plane thermal conductivity of 3.257 W m^-1 K^-1 and a specific gravity of 2.45 which is 86.1% of the traditional thermal interface material (DQL-TP300). At the same time, samples with hexagonal boron nitride oriented exhibited better performance of compression rate, breaking elongation and tensile strength. It provides a feasible solution for preparing the silicone rubber-based thermal interface materials with high thermal conductivity, low density and low cost.