Improving the thermal conductivity of epoxy composites using a combustion-synthesized aggregated β-Si3N4 filler with randomly oriented grains
Akihiro Shimamura, Yuji Hotta, Hideki Hyuga, Mikinori Hotta, Kiyoshi Hirao
Abstract
Abstract Electrically insulating and thermally conductive polymer matrix composites are desirable for industry applications as they improve the reliability of high-performance electronic devices, particularly via heat dissipation in devices loaded with several electronic components. In this study, an aggregated β-Si 3 N 4 filler with randomly oriented grains was produced via combustion synthesis to improve the thermal conductivity of epoxy composites. The thermal conductivities of the prepared composites were investigated as a function of the filler content, and the values were compared to those of composites loaded with commercial β-Si 3 N 4 (non-aggregated) . Negligible difference was observed in the thermal conductivities of both types of composites when the Si 3 N 4 content was below 40 vol%; however, above 40 vol%, the aggregated β-Si 3 N 4 filler-loaded composites showed higher thermal conductivities than the commercial β-Si 3 N 4 -loaded composites. The aggregated β-Si 3 N 4 filler-loaded composites exhibited isotropic thermal conductivities with a maximum value of 4.7 W m −1 K −1 at 53 vol% filler content, which is approximately 2.4 times higher than that of the commercial β-Si 3 N 4 -loaded composites, thereby suggesting that the morphology of the aggregated filler would be more efficient than that of the commonly used non-aggregated filler in enhancing the thermal conductivity of a polymer matrix composite.