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: 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: An apparatus (1) includes a supporting base material (12) that supports an element (11), a heat-dissipating member (13) on which the supporting base material (12) is installed, and an adhesive layer (14) disposed between the heat-dissipating member (13) and the supporting base material (12). The glass transition temperature of the adhesive layer (14) is equal to or lower than ?30° C.

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 (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.

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: An optical waveguide includes a clad layer, a core layer and a clad layer which are laminated together in this order from a lower side thereof. Within the core layer, a core portion and a side clad portion provided adjacent to the core portion so as to surround side surfaces of the core portion are formed. Further, a part of the side clad portion prevents a left side end of the core portion from being exposed outside. A mirror formation region is constituted from a region consisting of such a part of the side clad portion and a part of each of the clad layers located thereabove and therebelow. This mirror formation region is subjected to digging processing so that a concave portion is formed. An inner surface of this concave portion serves as the mirror. From the mirror, a material other than a material constituting the core portion, that is, a material constituting each of the clad layers and a material constituting the side clad portion are exposed.

Abstract: A substrate on which an optical element is mounted is provided, including: an optical element; an optical circuit substrate which is formed by an optical waveguide layer having a core portion and cladding portions; and an electrical circuit substrate on which is provided a mounting portion that is used for mounting the optical element, wherein the optical element is mounted on the electrical circuit substrate via the optical circuit substrate and wherein the optical circuit substrate has an optical element mounted thereon and is provided with a receptor structure having a conductive portion that conducts electricity between an electrode of the optical element and an electrode of the electrical circuit substrate.

Abstract: An optical waveguide includes a clad layer, a core layer and a clad layer which are laminated together in this order from a lower side thereof. Within the core layer, a core portion and a side clad portion provided adjacent to the core portion so as to surround side surfaces of the core portion are formed. Further, a part of the side clad portion prevents a left side end of the core portion from being exposed outside. A mirror formation region is constituted from a region consisting of such a part of the side clad portion and a part of each of the clad layers located thereabove and therebelow. This mirror formation region is subjected to digging processing so that a concave portion is formed. An inner surface of this concave portion serves as the mirror. From the mirror, a material other than a material constituting the core portion, that is, a material constituting each of the clad layers and a material constituting the side clad portion are exposed.

Abstract: A substrate on which an optical element is mounted is provided, including: an optical element; an optical circuit substrate which is formed by an optical waveguide layer having a core portion and cladding portions; and an electrical circuit substrate on which is provided a mounting portion that is used for mounting the optical element, wherein the optical element is mounted on the electrical circuit substrate via the optical circuit substrate and wherein the optical circuit substrate has an optical element mounted thereon and is provided with a receptor structure having a conductive portion that conducts electricity between an electrode of the optical element and an electrode of the electrical circuit substrate.

Abstract: A substrate on which an optical element is mounted is provided, including: an optical element; an optical circuit substrate which is formed by an optical waveguide layer having a core portion and cladding portions; and an electrical circuit substrate on which is provided a mounting portion that is used for mounting the optical element, wherein the optical element is mounted on the electrical circuit substrate via the optical circuit substrate and wherein the optical circuit substrate has an optical element mounted thereon and is provided with a receptor structure having a conductive portion that conducts electricity between an electrode of the optical element and an electrode of the electrical circuit substrate.

Abstract: A substrate on which an optical element is mounted is provided, including: an optical element; an optical circuit substrate which is formed by an optical waveguide layer having a core portion and cladding portions; and an electrical circuit substrate on which is provided a mounting portion that is used for mounting the optical element, wherein the optical element is mounted on the electrical circuit substrate via the optical circuit substrate and wherein the optical circuit substrate has an optical element mounted thereon and is provided with a receptor structure having a conductive portion that conducts electricity between an electrode of the optical element and an electrode of the electrical circuit substrate.