Abstract: A substrate for a power module (100) of the present invention includes a metal substrate (101), an insulating resin layer (102) provided on the metal substrate (101), and a metal layer (103) provided on the insulating resin layer (102). The insulating resin layer (102) includes a thermosetting resin (A) and inorganic fillers (B) dispersed in the thermosetting resin (A), a maximum value of a dielectric loss ratio of the insulating resin layer (102) at a frequency of 1 kHz and 100° C. to 175° C. is equal to or less than 0.030, and a change in a relative permittivity is equal to or less than 0.10.

Abstract: A substrate for a power module (100) of the present invention includes a metal substrate (101), an insulating resin layer (102) provided on the metal substrate (101), and a metal layer (103) provided on the insulating resin layer (102). The insulating resin layer (102) includes a thermosetting resin (A) and inorganic fillers (B) dispersed in the thermosetting resin (A), a maximum value of a dielectric loss ratio of the insulating resin layer (102) at a frequency of 1 kHz and 100° C. to 175° C. is equal to or less than 0.030, and a change in a relative permittivity is equal to or less than 0.10.

Abstract: A thermally conductive sheet of the present invention includes a thermosetting resin (A), and an inorganic filler material (B) which is dispersed in the thermosetting resin (A). In the thermally conductive sheet according to the present invention, the volume resistivity of the cured product of the thermally conductive sheet, which is measured one minute later after an applied voltage of 1000 V is applied thereto on the basis of JIS K 6911 and at a temperature of 175° C., is greater than or equal to 1.0×108 ?·m.

Abstract: The thermal conductive resin composition of first embodiment includes an epoxy resin, a cyanate resin, and thermal conductive filler. It has a thermal conductivity at 25° C., and cracking does not occur when a specific flex resistance test is carried out. The thermal conductive resin composition of a second embodiment includes an epoxy resin, a thermal conductive filler, and silica nanoparticles. An average particle diameter D50 of the silica nanoparticles is equal to or more than 1 nm and equal to or less than 100 nm, a content of the silica nanoparticles is equal to or more than 0.3% by mass and equal to or less than 2.5% by mass with respect to 100% by mass of a total solid content of the thermal conductive resin composition. The thermal conductive filler includes secondary agglomerated particles constituted of primary particles of scale-like boron nitride.

Abstract: A thermally conductive sheet of the present invention includes a thermosetting resin (A) and an inorganic filler material (B) that is dispersed in the thermosetting resin (A). In the thermally conductive sheet of the present invention, at a frequency of 1 kHz and at a temperature of 100° C. to 175° C., the maximum value of a dielectric loss factor of a cured product of the thermally conductive sheet is less than or equal to 0.030, and a change in relative dielectric constant of the cured product of the thermally conductive sheet is less than or equal to 0.10.

Abstract: A thermally conductive sheet of the present invention includes a thermosetting resin (A), and an inorganic filler material (B) which is dispersed in the thermosetting resin (A). In the thermally conductive sheet according to the present invention, the volume resistivity of the cured product of the thermally conductive sheet, which is measured one minute later after an applied voltage of 1000 V is applied thereto on the basis of JIS K 6911 and at a temperature of 175° C., is greater than or equal to 1.0×108 ?·m.

Abstract: A thermally conductive sheet of the present invention includes a thermosetting resin (A) and an inorganic filler material (B) that is dispersed in the thermosetting resin (A). In the thermally conductive sheet of the present invention, at a frequency of 1 kHz and at a temperature of 100° C. to 175° C., the maximum value of a dielectric loss factor of a cured product of the thermally conductive sheet is less than or equal to 0.030, and a change in relative dielectric constant of the cured product of the thermally conductive sheet is less than or equal to 0.10.

Abstract: A resin composition for a thermally conductive sheet includes a thermosetting resin and a filler dispersed in the thermosetting resin. The filler includes secondary agglomerated particles satisfying the following conditions: a void is formed in the central portion; a communicating pore which begins from the void and communicates with the outer surface of the secondary agglomerated particle is formed; and the ratio of the average pore diameter of the communicating pores to the average void diameter of the voids is equal to or more than 0.05 and equal to or less than 1.0.

Abstract: A thermally conductive sheet includes a thermosetting resin and an inorganic filler material. When a pore diameter distribution is measured through mercury intrusion technique for the inorganic filler material, a pore diameter distribution curve of the inorganic filler material has a first maximum value in the range where the pore diameter R is greater than or equal to 0.1 ?m and less than or equal to 5.0 ?m, and a second maximum value in the range where the pore diameter R is greater than or equal to 10 ?m and less than or equal to 30 ?m, and the difference between a second pore diameter at the second maximum value and a first pore diameter at the first maximum value is greater than or equal to 9.9 ?m and less than or equal to 25 ?m.

Abstract: A thermally conductive sheet includes a thermosetting resin and an inorganic filler material dispersed in the thermosetting resin. Measuring a pore diameter distribution through mercury intrusion technique for the inorganic filler material included in an incineration residue after a cured product of the thermally conductive sheet is heated and incinerated at 700° C. for four hours, a porosity of the inorganic filler material represented as 100×b/a is greater than or equal to 40% and less than or equal to 65% given that a is the volume of particles of the inorganic filler material included in the incineration residue, and b is the volume of voids in the particles of the inorganic filler material included in the incineration residue. An average pore diameter of the inorganic filler material included in the incineration residue is greater than or equal to 0.20 ?m and less than or equal to 1.35 ?m.

Abstract: A thermally conductive sheet includes a thermosetting resin (A) and an inorganic filler material (B) which is dispersed in the thermosetting resin (A). In the thermally conductive sheet, when a pore diameter distribution is measured through mercury intrusion technique for the inorganic filler material (B) that is included in an incineration residue after a cured product of the thermally conductive sheet is heated at 700° C. for four hours and is incinerated, a pore diameter distribution curve, that is measured through the mercury intrusion technique and is plotted with a pore diameter R as a horizontal axis and a logarithmic derivative of a pore volume (dV/d log R) as a vertical axis, has a peak (P) in the range where the pore diameter R is greater than or equal to 1.0 ?m and is less than or equal to 10.0 ?m, and the peak (P) is configured of two or more overlapping peaks.