High thermal conductivity of epoxy-based composites utilizing 3D porous boron nitride framework

With the rapid development of the third generation of wide bandgap semiconductor devices, there is an urgent need for highly thermally conductive and electrically insulating packaging materials to solve the heat dissipation problem in the microelectronic devices. In this work, the three-dimensional boron nitride (3D-BN) is successfully constructed by using a facile method, where the healthy and non-toxic food-grade material, curdlan, is used to provide a stable skeletons for growing 3D-BN using an aqueous foaming technique combined with a freeze-drying process. The thermally conductive network of 3D-BN is beneficial to improve the thermal conductivity of the epoxy resin (EP). The thermal conductivity of 1.63 W/(m·K) is obtained in the 3D-BN/EP composites at a BN content of 29.67 wt%, which is 9.1 times higher than that of pure EP. More importantly, the prepared composites also maintain excellent electrical insulation and dielectric properties, exhibiting a good potential to be used as the thermal interface material in the electronic devices.