Abstract: An object of the present invention is to provide: a dry film comprising a resin layer which has excellent detachability from a carrier film and in which cracking and powdering are inhibited; and a printed wiring board comprising a cured article obtained by curing the dry film. The dry film comprises a resin layer containing a thermosetting resin component, a filler and at least two solvents, wherein the at least two solvents both have a boiling point of 100° C. or higher and the boiling points of the at least two solvents are different by not less than 5° C.

Abstract: An object of the present invention is to provide: a heat-curable composition capable of yielding a cured article in which crack generation during a heating-cooling cycle can be inhibited; a dry film thereof; and a printed wiring board comprising the cured article. The heat-curable composition is characterized by comprising a semisolid or a solid epoxy compound and a curing accelerator that is made miscible with the epoxy compound when heated at 130 to 220° C. The dry film comprises a resin layer formed from this heat-curable composition, and the printed wiring board comprises a cured article obtained from the heat-curable composition or the dry film.

Abstract: A dry film includes a carrier film, a thermosetting resin composition layer, and a photocurable resin composition layer formed between the carrier film and the thermosetting resin composition layer. The thermosetting resin composition layer is formed by applying and drying a thermosetting resin composition. The photocurable resin composition layer is formed by applying and drying a photocurable resin composition. A method of producing a printed writing board includes forming a resin insulation layer which includes a thermosetting resin composition layer and a photocurable resin composition layer on the substrate, in the order of the thermosetting resin composition layer and the photocurable resin composition layer from a surface side of the substrate, patterning the resin insulation layer by photolithographic approach, and patterning the resin insulation layer by laser processing.

Abstract: An object of the present invention is to provide: a heat-curable composition capable of yielding a cured article in which crack generation during a heating-cooling cycle can be inhibited; a dry film thereof; and a printed wiring board comprising the cured article. The heat-curable composition is characterized by comprising a semisolid or a solid epoxy compound and a curing accelerator that is made miscible with the epoxy compound when heated at 130 to 220° C. The dry film comprises a resin layer formed from this heat-curable composition, and the printed wiring board comprises a cured article obtained from the heat-curable composition or the dry film.

Abstract: An object of the present invention is to provide: a dry film comprising a resin layer which has excellent detachability from a carrier film and in which cracking and powdering are inhibited; and a printed wiring board comprising a cured article obtained by curing the dry film. The dry film comprises a resin layer containing a thermosetting resin component, a filler and at least two solvents, wherein the at least two solvents both have a boiling point of 100° C. or higher and the boiling points of the at least two solvents are different by not less than 5° C.

Abstract: [Problem] Provided are: a pattern forming method by which a pattern can be formed by development using a thermosetting resin composition and a cured layer having excellent curability can be obtained; a thermosetting resin composition used in the pattern forming method; and a printed circuit board. [Means for Solution] The pattern forming method according to the present invention is characterized by comprising the steps of: (A) forming a resin layer composed of an alkali-developable thermosetting resin composition comprising a photobase generator on a substrate; (B) activating the photobase generator contained in the alkali-developable thermosetting resin composition by irradiation with a light in a pattern form so as to cure an irradiated part; and (C) forming a negatively patterned layer by removing a non-irradiated part by alkali development.

Abstract: Provided are: a thermosetting resin composition in which a cured product is excellent in low warp properties, thermal cycle characteristics, and the like, and occurrence of cracking of a coating film in a B-stage state is suppressed; a cured product thereof; and a printed wiring board in which the cured product is used. The thermosetting resin composition comprises: (A) an epoxy resin; (B) a curing agent for an epoxy resin; (C) spherical silicon dioxide and/or spherical aluminum oxide; and (D) a block copolymer.

Abstract: A process for the preparation of a printed wiring board that can prevent generation of crack and warpage is provided. A process for the preparation of a printed wiring board, comprising a step of forming a curable resin layer and a non-curable resin layer sequentially on a surface of a substrate; a step of forming depressions in the non-curable resin layer and the curable resin layer from the non-curable resin layer side; a step of applying a catalyst for plating to a surface of the non-curable resin layer and surfaces of the depressions; a step of removing the non-curable resin layer and the catalyst for plating provided on the surface of the non-curable resin layer; and a step of electroless plating the surfaces of the depressions.

Abstract: The present invention provides a dry film capable of forming a cured coating film having an excellent laser processability and a desmear resistance, and a printed writing board using the same. Further, the present invention provides a method of producing a printed writing board for a flip-chip mounting substrate capable of simply and inexpensively forming a dam preventing from spreading an underfill, a printed writing board obtained by the method of producing, and a flip-chip mounting substrate in which a chip is subjected to flip chip mounting on the printed writing board. A dry film comprising: a carrier film and a photocurable resin composition layer (L1) formed by applying and drying a photocurable resin composition; and at least a thermosetting resin composition layer (L2) formed by applying and drying a thermosetting resin composition in a gap between the photocurable resin composition layer (L1) and the carrier film.

Abstract: [Problem] Provided are: a pattern forming method by which a pattern can be formed by development using a thermosetting resin composition and a cured layer having excellent curability can be obtained; a thermosetting resin composition used in the pattern forming method; and a printed circuit board. [Means for Solution] The pattern forming method according to the present invention is characterized by comprising the steps of: (A) forming a resin layer composed of an alkali-developable thermosetting resin composition comprising a photobase generator on a substrate; (B) activating the photobase generator contained in the alkali-developable thermosetting resin composition by irradiation with a light in a pattern form so as to cure an irradiated part; and (C) forming a negatively patterned layer by removing a non-irradiated part by alkali development.

Abstract: Provided is a heat-curable resin filler in which the deterioration in thixotropic properties over time can be prevented and which has excellent shape retaining properties after being filled in hole parts in a printed wiring board and being cured and also has excellent abradability. The heat-curable resin filler comprises an epoxy resin, an epoxy resin curing agent, an inorganic filler and a fatty acid represented by the following general formula: (R1COO)n-R2 (wherein the substituent R1 represents a hydrocarbon group having 5 or more carbon atoms; the substituent R2 represents a hydrogen atom, an metal alkoxide group or a metal atom; and n is 1 to 4).