Hexagonal boron nitride powder

Abstract

This invention provides an h-BN powder that can further improve the thermal conductivity of heat dissipation components when used as a filler. A hexagonal boron nitride powder comprises primary particles and secondary particles formed by the aggregation of the primary particles. In a dry particle size distribution determined by laser diffraction particle size distribution measurement after the hexagonal boron nitride powder is sprayed at a pressure of 0.3 MPa, the proportion R1 of particles with a diameter of 20 μm or less is 0% to 50% by volume; the proportion R2 of particles with a diameter greater than 20 μm but less than 100 μm is 40% to 100% by volume; and the proportion R3 of particles with a diameter greater than 100 μm is 0% to 10% by volume.