Abstract: Provided is a stator coil, including: a coil conductor; a first insulating layer in which a first mica tape is wound and laminated around an outer periphery of the coil conductor; and a second insulating layer in which a second mica tape is wound and laminated around an outer periphery of the first insulating layer, wherein the first mica tape contains mica in a specific content, wherein 60 mass % or more of the mica contained in the first mica tape passes through a JIS standard sieve having a nominal opening of 250 ?m, wherein the first mica tape has a specific lamination thickness, and wherein 40 mass % or less of mica contained in the second mica tape passes through the JIS standard sieve having a nominal opening of 250 ?m.

Abstract: Provided is an insulating varnish composition, including: two or more kinds of epoxy resins; and a filler having an average primary particle diameter of 500 nm or less, wherein the two or more kinds of epoxy resins contain 80 mass % or more of an epoxy resin having a number of repetitions of 0 in a molecular structural formula thereof with respect to a total mass of the two or more kinds of epoxy resins.

Abstract: Provided is a stator coil, including: a coil conductor; a first insulating layer in which a first mica tape is wound and laminated around an outer periphery of the coil conductor; and a second insulating layer in which a second mica tape is wound and laminated around an outer periphery of the first insulating layer, wherein the first mica tape contains mica in a specific content, wherein 60 mass % or more of the mica contained in the first mica tape passes through a JIS standard sieve having a nominal opening of 250 ?m, wherein the first mica tape has a specific lamination thickness, and wherein 40 mass % or less of mica contained in the second mica tape passes through the JIS standard sieve having a nominal opening of 250 ?m.

Abstract: A method for manufacturing, by a transfer mold method, a power module equipped with a heat conductive insulating sheet in which an inorganic filler including secondary aggregated particles formed by aggregation of primary particles of scaly boron nitride is dispersed in a thermosetting resin, where curing of an uncured or semi-cured heat conductive insulating sheet during transfer molding is advanced under specific conditions. The method for manufacturing a power module equipped with a heat conductive insulating sheet has excellent thermal conductivity and electric insulation ability.

Abstract: A method for manufacturing, by a transfer mold method, a power module equipped with a heat conductive insulating sheet in which an inorganic filler including secondary aggregated particles formed by aggregation of primary particles of scaly boron nitride is dispersed in a thermosetting resin, where curing of an uncured or semi-cured heat conductive insulating sheet during transfer molding is advanced under specific conditions. The method for manufacturing a power module equipped with a heat conductive insulating sheet has excellent thermal conductivity and electric insulation ability.

Abstract: Provided is a thermosetting resin composition including an inorganic filler and a thermosetting resin matrix component, in which the inorganic filler includes secondary sintered particles each formed of primary particles of scaly boron nitride, and at least some of the secondary sintered particles each have a maximum cavity diameter of 5 ?m to 80 ?m. The thermosetting resin composition can be used for providing a heat conductive sheet in which electrical insulation property is kept by controlling where the defects such as voids and cracks occur and their size, and which has excellent heat conductivity.

Abstract: Provided is a thermosetting resin composition including an inorganic filler and a thermosetting resin matrix component, in which the inorganic filler includes secondary sintered particles each formed of primary particles of scaly boron nitride, and at least some of the secondary sintered particles each have a maximum cavity diameter of 5 ?m to 80 ?m. The thermosetting resin composition can be used for providing a heat conductive sheet in which electrical insulation property is kept by controlling where the defects such as voids and cracks occur and their size, and which has excellent heat conductivity.

Abstract: A method and device for detecting insulation degradation of a power module, which detects, in advance, degradation of an insulating sheet based on a current change immediately before breakdown of an insulation characteristic from a current value of a current flowing through the insulating sheet, thereby detecting a failure of a power module caused by the degradation of insulation.