Abstract: Provided is an insulating resin material capable of reducing surface roughness of the surface of a cured object, and, when a metal layer is formed on the surface of the cured object, increasing adhesive strength between the cured object and the metal layer. The insulating resin material of the present invention includes a thermosetting resin, a curing agent, a first inorganic filler surface-treated with a first silane coupling agent, and a second inorganic filler surface-treated with a second silane coupling agent. When absolute difference between SP values of a most-abundantly contained thermosetting resin and an organic group of the first silane coupling agent is defined as SP(A), and when absolute difference between SP values of the most-abundantly contained thermosetting resin and an organic group of the second silane coupling agent is defined as SP(B); (SP(A)?SP(B)) is not smaller than 0.5 but not larger than 3.5.

Abstract: A preliminary-cured material permits reduced surface roughness of a roughening-treated surface, and increase of an adhesive strength between a cured object and a metal layer. The preliminary-cured material is obtained by advancing curing of an epoxy resin material that contains an epoxy resin, a curing agent, and a silica. The preliminary-cured material includes a first principal surface to be roughening-treated, and a second principal surface. The silica includes a first small particle-diameter silica whose particle diameter is not smaller than 0.01 ?m but smaller than 0.5 ?m, and a second large particle-diameter silica whose particle diameter is not smaller than 0.5 ?m but not larger than 20 ?m. The first small particle-diameter silica is localized to exist in large quantity on a side of the first principal surface, and the second large particle-diameter silica is localized to exist in large quantity on a side of the second principal surface.

Abstract: Provided is an insulating resin material capable of reducing surface roughness of the surface of a cured object, and, when a metal layer is formed on the surface of the cured object, increasing adhesive strength between the cured object and the metal layer. The insulating resin material of the present invention includes a thermosetting resin, a curing agent, a first inorganic filler surface-treated with a first silane coupling agent, and a second inorganic filler surface-treated with a second silane coupling agent. When absolute difference between SP values of a most-abundantly contained thermosetting resin and an organic group of the first silane coupling agent is defined as SP(A), and when absolute difference between SP values of the most-abundantly contained thermosetting resin and an organic group of the second silane coupling agent is defined as SP(B); (SP(A)?SP(B)) is not smaller than 0.5 but not larger than 3.5.

Abstract: A preliminary-cured material permits reduced surface roughness of a roughening-treated surface, and increase of an adhesive strength between a cured object and a metal layer. The preliminary-cured material is obtained by advancing curing of an epoxy resin material that contains an epoxy resin, a curing agent, and a silica. The preliminary-cured material includes a first principal surface to be roughening-treated, and a second principal surface. The silica includes a first small particle-diameter silica whose particle diameter is not smaller than 0.01 ?m but smaller than 0.5 ?m, and a second large particle-diameter silica whose particle diameter is not smaller than 0.5 ?m but not larger than 20 ?m. The first small particle-diameter silica is localized to exist in large quantity on a side of the first principal surface, and the second large particle-diameter silica is localized to exist in large quantity on a side of the second principal surface.

Abstract: Provided is a laminated body capable of reducing the surface roughness of the surface of a roughening-treated cured body layer, and increasing the adhesive strength between the cured body layer and a metal layer. A laminated body includes a cured body layer formed by: laminating a resin film on a substrate, forming a preliminary-cured body layer by preliminary-curing the resin film at 100° C. to 200° C., and performing a roughening treatment on the surface of the cured object layer at 55° C. to 80° C. The resin film is formed from a resin composition including an epoxy resin, a phenol curing agent, a curing accelerator, and a surface-treated substance which is a surface treated, using 0.5 to 3.5 parts by weight of a silane coupling agent, on 100 parts by weight of inorganic filler with a mean particle diameter of 0.05 to 1.5 ?m. The silane coupling agent has an epoxy group, an imidazole group, or an amino group.

Abstract: A resin composition is provided which allows improvement of the ultraviolet laser processability of the resin and can be not only used as an electronic material for an insulating film of a build-up board and the like but also used to form a circuit board whose electrical insulating property does not deteriorate. A multilayer resin film employing the resin composition is provided. A resin composition is provided which contains a thermosetting resin (A), a curing agent (B), a silica (C), an ultraviolet absorber (D), and a solvent (E) and in which: the content of the ultraviolet absorber (D) is from 0.5 to 50 parts by weight per the total amount of the thermosetting resin (A), the curing agent (B), and the ultraviolet absorber (D); and the blending amount of the solvent (E) is from 20 to 500 parts by weight per 100 parts by weight of the total amount of the thermosetting resin (A) and the curing agent (B).