Effect of functionalization on thermal conductivity of hexagonal boron nitride/epoxy composites

Electronic equipment generates a significant amount of heat during operation with the trend of integrated circuit chips and electronic components towards miniaturization and multi-functionality. Consequently, guaranteeing safe and dependable functioning while appropriately dispersing heat has become a critical challenge in the development of the microelectronics sector. The emergence of thermal interface materials (TIMs) with high thermal conductivity can effectively address this issue. In this study, simulations and experiments were used to investigate the effects of functional groups, including hydroxyl (-OH), dopamine (DA) and silane coupling agent (KH550), and their grafting ratios on the thermal conductivity of hexagonal boron nitride/epoxy (h-BN/EP) composites. The interface thermal conduction results demonstrated that the modification of functional groups with a higher grafting ratio exhibited a larger enhancement, and KH550 outperformed DA and -OH in terms of the enhancing effect. Moreover, according to the effective medium theory (EMT), the simulated thermal conductivity of BN-KH550/EP composite (2 % grafting ratio of KH550, 10 vol% filling ratio of BN) was 0.692 W·m−1·K−1, 224.9% higher than that of pure epoxy resin. Additionally, the experimentally measured thermal conductivity was 0.703 W·m−1·K−1, showing good agreement with the simulation result and indicating EMT's accurate prediction for the h-BN/EP composites.