The 3D printing, also known as additive manufacturing, has been received a great attention recently due to a variety of factors such as a wider choice of materials, rapid prototyping and low volume productions. While the mechanical 3D printing is well established in the field of manufacturing mechanical parts and prototyping newly designed models as well as hobby recreation products, 3D printing of electrical circuits or components has not been developed much. It is still in the stage of concept which should be further moved into the practical use in industry. Researchers are focused on the materials including electrically conductive inks, semi-conducting pastes and insulating materials. However, for the 3D-printed electronic components to show an efficient performance, an effective dissipation of heat produced by the electronic components is essential. Epoxy resin systems are used for encapsulating a variety of electronic components because of their high thermal stability, high moisture resistance, and low cost. Unfortunately, the cured epoxy resin has low thermal conductivity (0.2 W/mK). In this study, we prepared a photocurable epoxy inks with high thermal conductivity for 3D printing application. In order to increase the thermal conductivity of the ink material, BN (boron nitride) was surface-modified for improved interaction. The surface-modified BN was confirmed by FT-IR. The thermal conductivities of photocured epoxy composites filled with modified-BN measured by hot disk method were in the range of 0.388 and 0.728 W/mK, respectively. Then, to evaluate the epoxy ink material as a 3D printing inks, a square line was printed using a dispenser. The effect of ink viscosity, printing speed, nozzle diameter on the line width, line thickness, and edge thickness was investigated.