Double core shell structured Al@Al2O3@SiO2 filled epoxy composites for thermal management application

Abstract

Polymer composites are preferred as thermal conductive interface materials because of their light weight, low cost, and ease of processing. However, polymers are subjected to low thermal conductivity. The enhancement of their thermal conductivity is often at the cost of deteriorating dielectric properties, resulting in a substantial increase in the dielectric constant, dielectric loss, and conductivity. In order to address this problem, we developed a double core shell structured Al@Al2O3@SiO2 filled epoxy composite to enhance the thermal conductivity as well as keep the low dielectric constant and dielectric loss. The thermal conductivity of the composite with a loading of 40 wt. % fillers can be enhanced by three times that of the pure epoxy. Compared with the composite loaded with the unmodified aluminum particles, the double core shell Al@Al2O3@SiO2 is more effective in curbing the trend of the steep rise of the dielectric constant, dielectric loss, and conductivity of the composites. The potential use of the obtained composites for the thermal management of power light emitting diodes (LEDs) and chips has also been demonstrated by a practical LED chip and the analysis of finite element simulation.