High thermally conductive epoxy composite inks cured by infrared laser irradiation for two-dimensional/three-dimensional printing technology

We propose a new fabrication method of high thermally conductive epoxy composites for 3 D printing technology, which is based on a thermosetting epoxy system containing graphene nanoplate (GNP) as an IR-absorbing material. Firstly, we developed highly heat-dissipating inks based on bisphenol A diglycidyl ether (DGEBA) type epoxy resins containing graphene nanoplate (GNP) which was used as a heat dissipating filler and, simultaneously, an IR-absorbing material for heat induced rapid curing of printed layer. h-BN was also added as a heat dissipating filler in order to increase the thermal conductivity and to decrease the electrical conductivity of the composite. Secondly, by using a micro dispenser equipped with an IR laser, 2D/3D line patterns of thermally conductive epoxy composites were printed and cured in-situ. Thermal and electrical conductivities of the resulting composites were discussed with respect to the resin compositions and the irradiation conditions. The highest thermal conductivity of 2.77 W/m·K was achieved when the contents of GNP and h-BN were 15.0 and 20.0 phr, respectively.