Self-assemblies of linearly aligned diamond fillers in polysiloxane/diamond composite films with enhanced thermal conductivity

Abstract

The relocation of diamond fillers was performed in polysiloxane-based composite films under different electric fields. The microscale diamond filler particles were dispersed by sonication in a prepolymer mixture of polysiloxane, followed by high-speed mixing. The homogeneous suspension was cast onto a polyamide spacer of microscale thickness and subjected to three different electric fields: AC, DC, and switched DC, before the mixture became cross-linked. Analysis revealed that self-assemblies of linearly aligned diamond fillers (LADFs) were fabricated in the composite film, connecting the film planes as bridges with different thicknesses depending on the applied electric field. Composites with assemblies of LADFs exhibited enhanced thermal conductivity and electrical insulation, and are attractive for application as thermal interface materials in the semiconductor industry. (C) 2011 Elsevier Ltd. All rights reserved.