Vertically-aligned Boron Nitride Composite As a Highly Thermally Conductive Material Using Magnetic Field-Assisted Three-Dimensional Printing

With the development of electronic devices, the efficient thermal management of electronic devices has attracted increasing attention. In this study, we fabricated a composite that exhibited effective thermal conductivity by vertically aligning fillers using a generated vertical magnetic field in a three-dimensional (3D) printer. To this end, magnets were placed in the printer such that the same poles faced each other. Consequently, the magnets repelled each other and formed a vertical magnetic field, which enabled the vertical placement of Fe3O4-decorated BN in UV resin. UV resin is a mixture of 1,6-hexanediol diacrylate, diurethane dimethacrylate, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide in a mass ratio of 69 : 30: 1. Owing to the effective transfer of heat in the vertical direction, the printed composite achieved a thermal conductivity value of 1.36 W m-1 K-1 at a filler content of 17.5 vol%. This result demonstrate the effectiveness of this method for aligning fillers on a slurry within a 3D printer, and we believe that it will provide a new paradigm for composite printing.