Preparation of boron nitride nanosheets using a chemical exfoliation method as a thermal conductive filler for the development of silicone thermal pads: Part II: Optimization of process parameter design on the development of a silicone thermal pad

Abstract

This study developed a silicone thermal pad with high thermal conductivity and high mechanical properties. Boron nitride nanosheets (BNNSs) with different lamella thicknesses were prepared in Part I and Al₂O₃ was filled with silicone rubber to prepare silicone thermal pads. The silicone thermal pads were prepared using the Taguchi method and the elimination and choice translating reality method. BNNSs with different lamella thicknesses, BNNS loading level, and Al₂O₃ loading level were set as control factors for the experiment. The effect of the three sets of control factors on the thermal conductivity, tensile property, and hardness of the silicone thermal pads was discussed so as to determine the optimum product optimization process parameters. According to the experimental results, the optimum experimental combination was BNNSs with lamella thickness (B24), a BNNS loading level of 20 wt%, and an Al₂O₃ loading level of 60 wt%. The thermal conductivity of the silicone thermal pads prepared by thermosetting was 5.25 W/mK, the maximum tensile strength was 7.55 kg/cm², and the Shore hardness was 65.2 (Shore A). Under identical conditions, the thermal conductivity and tensile strength were higher than that of commercially available silicone thermal pads by 34.48% and 20.26%, respectively. The control factor influencing the thermal conductivity and tensile strength of silicone thermal pads was the BNNS loading level, with contribution degrees of 34.66% and 50.13%, respectively. Accurate parameter settings could be obtained for silicone thermal pad processes.