Orientation Effect of Nano-Alumina Coated Conductive Fillers on Dielectric Properties of Epoxy Composites

This paper deals with effects of filler orientation in epoxy composites on the dielectric property and thermal conductivity. Aluminum particles coated by nano-alumina are used as filler. During curing process of epoxy composite, an electric field is applied to form chain-like structure of the particles. Dielectric property and thermal conductivity are measured after full hardening process. As a result, the formation of chain-like structure of the particles results in a further increase in the dielectric constant and thermal conductivity of the composites. A reduction of filler concentration in the composites is also discussed.