Thermal Conductivity Improvement by Cu Surface Treatments and Incorporation of PMMA Beads on Cu/Epoxy Composites

Thermal conductivity and surface resistance of epoxy-based composites with dendritic Cu fillers with different surface treatments have been investigated. Thermal conductivity of the composites was measured by a guarded heat flow meter method. Thermal conductivity increased when the Cu fillers were treated by 1HNO(3) and 3-aminopropyltrimethoxysilane (APTMS). A parallel study on the effect of incorporation of PMMA beads in epoxy matrix was also carried out. PMMA beads led a good contact between Cu fillers and improved the thermal conductivity of the composites for all filler concentrations. The incorporation of 12.5% of PMMA bead/(PMMA bead + epoxy) at Cu filler content of 50 wt% resulted in 0.65 W/mK of thermal conductivity, which is 41% increase compared to the epoxy-based composites without PMMA beads. This paper provides a simple and economical way to produce thermally conductive polymer composites.