Abstract: Aggregated boron nitride particles in which hexagonal boron nitride primary particles are aggregated and which include an alkyl group-containing silane coupling agent. The present invention can provide boron nitride powder for obtaining a heat-dissipation sheet with excellent thermal conductivity, a heat-dissipation sheet with excellent thermal conductivity, and a method of producing a heat-dissipation sheet with excellent thermal conductivity.

Abstract: A heat dissipation sheet obtained by molding a heat conductive resin composition, the heat dissipation sheet having a partial discharge start voltage of 2800 to 5000 kV/mm. The method for producing the heat dissipation sheet includes a step of blending a resin and a boron nitride powder containing at least an aggregated boron nitride particle formed by an aggregation of hexagonal boron nitride primary particles to prepare a heat conductive resin composition, a step of molding the heat conductive resin composition into a sheet shape to prepare a heat conductive resin composition sheet, and a step of heating and pressurizing the heat conductive resin composition sheet under a vacuum. Thus, a heat dissipation sheet excellent in heat conductivity and insulation property and a method can produce the heat dissipation sheet.

Abstract: A boron nitride powder, containing at least an aggregated boron nitride particle formed by an aggregation of hexagonal boron nitride primary particles, the powder having a particle size distribution including at least a first maximum point, a second maximum point at which a particle size is larger than at the first maximum point, and a third maximum point at which a particle size is larger than at the second maximum point. The heat dissipation sheet is obtained by molding a heat conductive resin composition containing the boron nitride powder and a resin. The method for producing a heat dissipation sheet includes blending the boron nitride powder and a resin to prepare a heat conductive resin composition, molding the heat conductive resin composition into a sheet shape to prepare a heat conductive resin composition sheet, and heating and pressurizing the heat conductive resin composition sheet under a vacuum.

Abstract: A heat-conductive resin composition containing an inorganic filler component and a resin component, wherein the inorganic filler component includes first and second inorganic fillers, a particle size distribution has a first maximum point caused by the first inorganic filler and a second maximum point caused by the second, the diameter at the first maximum point is 15 ?m or more, the diameter at the second is ? or less that at the first, an integrated amount of frequency between a peak start and end in a peak having the first maximum point is 50% or more, and the first inorganic filler is formed by agglomerating hexagonal boron nitride primary particles and has a crushing strength of 6 MPa or more. The heat dissipation sheet is obtained by molding the heat-conductive resin composition.

Abstract: A heat dissipation sheet having excellent thermal conductance, is a molded thermally conductive resin composition prepared by blending an inorganic filler component and a resin component, wherein the inorganic filler component particle size distribution includes a first maximum point attributable to the first inorganic filler and a second maximum point attributable to the second inorganic filler; the particle size at the first maximum point is 15 ?m or more; the particle size at the second maximum point is ? or less the particle size at the first maximum point; and an accumulated amount of the frequency between the peak start and the peak end of the peak having the first maximum point is 50% or more, and which has a surface roughness of from 1.5 to 3.0 ?m and a thickness of 0.2 mm or less.

Abstract: In an electric vehicle inverter apparatus 100, a vehicle control controller 15 detects a switch open signal output from a collision detector 16 when the collision detector 16 is caused by a collision between electric vehicles to operate. Then, an inverter main circuit connection switch 10 of a high-voltage battery unit 8 is put into an open state. Thus, the direct-current power supply from a high-voltage battery 12 to a DC bus portion is interrupted. In addition, electric charges charged into a main circuit capacitor 7 are discharged by a forced discharge circuit portion 22b.

Abstract: In an electric vehicle inverter apparatus 100, a vehicle control controller 15 detects a switch open signal output from a collision detector 16 when the collision detector 16 is caused by a collision between electric vehicles to operate. Then, an inverter main circuit connection switch 10 of a high-voltage battery unit 8 is put into an open state. Thus, the direct-current power supply from a high-voltage battery 12 to a DC bus portion is interrupted. In addition, electric charges charged into a main circuit capacitor 7 are discharged by a forced discharge circuit portion 22b.