Effect of Al₂O₃ coverage on SiC particles for electrically insulated polymer composites with high thermal conductivity

Al₂O₃-covered SiC/epoxy composites were prepared using a simple sol-gel method. The results of FE-SEM, TGA, and XPS indicated that the surfaces of the SiC particles had a large, dense, and homogenous distribution of Al₂O₃. It was found that the introduction of Al₂O₃ on the SiC surface improved the interfacial adhesion between the epoxy matrix and SiC particles; this resulted in an increase in the thermal conductivity of the composites since the thermal boundary resistance at the filler-matrix interface was decreased. In addition, Al₂O₃-covered SiC composites showed decreased electrical conductivity owing to decreased electron tunneling compared with raw SiC composites. Thus, the Al₂O₃-covered SiC composites prepared in the present work could prove to be desirable polymer composites to be used as thermal interface materials that are employed in the electronics industry.