A low-cost approach for fabricating thermally conductive SiC/polymer composites by pre-constructing ceramic skeleton from photovoltaic silicon waste

Abstract

With the increasing integration of electronic equipment, it is urgent to develop thermal management materials with high heat dissipation performance. Silicon carbide (SiC) is one of the preferred fillers for the preparation of ceramic/polymer composites, and has widespread applicability in thermal-management materials. In this study, low-cost photovoltaic silicon waste (PSW) was used as the silicon source to construct three-dimensional SiC (3D-SiC) skeletons by freeze-forming and in-situ reaction sintering, and then used to prepare SiC/epoxy (EP) composites via vacuum impregnation. When the content of SiC filler was 20.63 vol%, the thermal conductivity of the composite reached 1.79 W·m−1·K−1, approximately 8.95 times that of pure epoxy. Compared with the pure epoxy substrate, the composite substrates with higher thermal conductivity showed excellent heat dissipation performance in practical applications. The high thermal conductivity of the composite was closely related to the vertically-oriented arrangement of SiC powders in the 3D-SiC skeleton, which effectively reduces phonon scattering and forms a multi-channel “expressway” that is conducive to the efficient heat transfer of phonons. This study provides a novel method for the development of thermally conductivity ceramic/polymer composites, which is of great significance in the low-cost preparation of thermal management materials.