Abstract: An aluminum nitride granular powder is constituted by aluminum nitride sintered granules, the aluminum nitride granular powder having a maximum peak diameter of 30 ?m to 200 ?m in a volume-based particle diameter distribution obtained from maximum lengths of the aluminum nitride sintered granules measured with use of a dry particle image analyzer, with regard to the aluminum nitride sintered granules each of which has a particle diameter of not less than 30% of the maximum peak diameter, a ratio of the number of particles having an HS roundness value of 0.5 to 0.8 as measured with use of the dry particle image analyzer being not less than 15% relative to the aluminum nitride sintered granules each having the particle diameter.

Abstract: An aluminum nitride particle including at least a first truncated six-sided pyramid (1-a) and a second truncated six-sided pyramid (1-b), the aluminum nitride particle having a shape such that a lower base (3) of the first truncated six-sided pyramid (1-a) and a lower base (3) of the second truncated six-sided pyramid (1-b) face each other, the first truncated six-sided pyramid (1-a) and the second truncated six-sided pyramid (1-b) each having an upper base (2) with an area S1 of not less than 60 ?m2 and not more than 4800 ?m2, and each having a ratio (S1/S2) of the area S1 to an area S2 of the lower base (3) being not less than 0.5 and less than 1, the first truncated six-sided pyramid (1-a) and the second truncated six-sided pyramid (1-b) respectively having a height h1 and a height h2 each being not less than 5 ?m and not more than 20 ?m.

Abstract: An aluminum nitride particle including at least a first truncated six-sided pyramid (1-a) and a second truncated six-sided pyramid (1-b), the aluminum nitride particle having a shape such that a lower base (3) of the first truncated six-sided pyramid (1-a) and a lower base (3) of the second truncated six-sided pyramid (1-b) face each other, the first truncated six-sided pyramid (1-a) and the second truncated six-sided pyramid (1-b) each having an upper base (2) with an area Si of not less than 60 ?m2 and not more than 4800 ?m2, and each having a ratio (S1/S2) of the area Si to an area S2 of the lower base (3) being not less than 0.5 and less than 1, the first truncated six-sided pyramid (1-a) and the second truncated six-sided pyramid (1-b) respectively having a height h1 and a height h2 each being not less than 5 ?m and not more than 20 ?m.

Abstract: An aluminum nitride particle including: a plurality of planes randomly arranged in a surface of the particle, the plurality of planes forming an obtuse ridge part or an obtuse valley part in the surface of the particle, the plurality of planes being observable in a scanning electron micrograph with 500 times magnification; wherein the particle has a longer diameter L of 20 to 200 ?m; a ratio L/D of the longer diameter L (unit: ?m) to a shorter diameter D (unit: ?m) of the particle is 1 to 1.25; and the plurality of planes comprise a first plane, wherein an area S (unit: ?m2) of the first plane satisfies S/L?1.0 ?m.

Abstract: To provide an aluminum nitride particle having a hexagonal columnar barrel part and bowl-like projection parts at both ends of the columnar part, wherein the long diameter (D) of the barrel part is 10 to 250 ?m, the ratio (L1/D) of the distance (L1) between the apexes of the two projection pars to the long diameter (D) of the barrel part is 0.7 to 1.3, and the percentage of the length or thickness (L2) of the barrel part to the distance (L1) between the apexes of the two projection parts is 10 to 60%. The aluminum nitride particle can provide high heat conductivity and excellent electric insulation to a resin when it is filled into the resin.

Abstract: An aluminum nitride particle including: a plurality of planes randomly arranged in a surface of the particle, the plurality of planes forming an obtuse ridge part or an obtuse valley part in the surface of the particle, the plurality of planes being observable in a scanning electron micrograph with 500 times magnification; wherein the particle has a longer diameter L of 20 to 200 ?m; a ratio L/D of the longer diameter L (unit: ?m) to a shorter diameter D (unit: ?m) of the particle is 1 to 1.25; and the plurality of planes comprise a first plane, wherein an area S (unit: ?m2) of the first plane satisfies S/L?1.0 ?m.

Abstract: To provide an aluminum nitride particle having a hexagonal columnar barrel part and bowl-like projection parts at both ends of the columnar part, wherein the long diameter (D) of the barrel part is 10 to 250 ?m, the ratio (L1/D) of the distance (L1) between the apexes of the two projection pars to the long diameter (D) of the barrel part is 0.7 to 1.3, and the percentage of the length or thickness (L2) of the barrel part to the distance (L1) between the apexes of the two projection parts is 10 to 60%. The aluminum nitride particle can provide high heat conductivity and excellent electric insulation to a resin when it is filled into the resin.