Development of highly thermoconductive epoxy composites

Epoxy resins with controlled high-order structures show higher thermal conductivity than conventional ones, because the ordered-structure domains consisting of self-arranged `mesogen' groups of epoxy monomers promote smooth phonon transportation. In this report, we investigated composites consisting of these resins and ceramic fillers to obtain epoxy resin composites having both high isotropic thermal conductivities and electrical insulation. Though these epoxy monomers are difficult to handle because of their crystallinity and poor solubility in solvents, we confirmed that the conventional processes for thermosetting resin forming, such as "varnish coating" and "transfer molding", are applicable to these composites by optimizing the molecular architectures of hardeners, the composition of solvents, etc. As a result, excellent thermal conductivity (i.e., higher than 10 W/mK) was attained for the composites using the developed mesogen type epoxy monomers.