Abstract: A substrate for a printed wiring board, the substrate includes a base film containing polyimide as a main component and a sinter layer disposed on at least a portion of a surface of the base film and containing copper nanoparticles. The base film contains a nitrogen atom bonded to a copper atom of the copper nanoparticles, an average number of the nitrogen atom bonded to the copper atom per unit area of the surface of the base film on which the sinter layer is disposed is 2.6×1018 atoms/m2 to 7.7×1018 atoms/m2, and the average number is an average number calculated for a measurement region estimated to have a thickness of 3 nm from a measurement value of the surface of the base film measured by X-ray photoelectron spectroscopy.

Abstract: The base material for printed circuit board according to one aspect of the present disclosure is a base material for printed circuit board comprising a base film having an insulating property, a sintering layer inducing a plurality of copper particles and formed on at least one surface of the base film and an electroless copper plating layer formed on a surface of the sintering layer, the surface being on an opposite side to the base film, and filled in the sintering layer, and wherein a lightness L* of a surface of the electroless copper plating layer, the surface being on an opposite side to the sintering layer, is 45.0 or more and 85.0 or less, a chromaticity a* thereof is 5.0 or more and 25.0 or less, and a chromaticity b* thereof is 5.0 or more and 25.0 or less.

Abstract: A base material for a printed circuit board includes a base film having an insulating property, and a sintered body layer including metal particles and layered on at least one surface of the base film. The sintered body layer includes sintered particles that are derived from the metal particles and partially embedded into the surface of the base film. The embedment ratio of the sintered particles is greater than or equal to 10% and less than or equal to 90%.

Abstract: A resin film according to one aspect of the present invention is a resin film having polyimide as a main component, the resin film including a modified layer formed in a depth direction from at least one side of the resin film; and a non-modified layer other than the modified layer, wherein a ring-opening rate of an imide ring of the polyimide in the modified layer is higher than a ring-opening rate of an imide ring of the polyimide in the non-modified layer, and an average thickness of the modified layer from the one side of the resin film is greater than or equal to 10 nm and less than or equal to 500 nm.

Abstract: According to one aspect of the present invention, a substrate for a printed circuit board includes: an insulating base film; and a metal layer that covers an entirety or a part of one or both surfaces of the base film, wherein the metal layer includes a sintered body layer of copper nanoparticles, and wherein the sintered body layer includes nitrogen atoms by greater than or equal to 0.5 atomic % and less than or equal to 5.0 atomic %.

Abstract: A resin film according to one aspect of the present invention is a resin film having polyimide as a main component, the resin film including a modified layer formed in a depth direction from at least one side of the resin film; and a non-modified layer other than the modified layer, wherein a ring-opening rate of an imide ring of the polyimide in the modified layer is higher than a ring-opening rate of an imide ring of the polyimide in the non-modified layer, and an average thickness of the modified layer from the one side of the resin film is greater than or equal to 10 nm and less than or equal to 500 nm.

Abstract: A substrate for a printed circuit board according to an embodiment of the present invention includes a resin film and a metal layer stacked on at least one of surfaces of the resin film. An average diffusion depth of a main metal of the metal layer in the resin film is 100 nm or less after a weather resistance test in which the substrate is held at 150° C. for seven days. The average diffusion depth is preferably 80 nm or less before the weather resistance test.

Abstract: An object is to provide a substrate for a printed wiring board that has good circuit formability while maintaining adhesion strength between a conductive layer (2) and a base film (1). The substrate includes a base film having an insulating property (1) and a conductive layer (2) formed on at least one surface of the base film (1). The maximum height Sz, which is defined in ISO25178, of the surface of the base film (1) is 0.05 ?m or more and less than 0.9 ?m.

Abstract: According to an embodiment of the present invention, a substrate for a printed circuit board, the substrate including a resin film and a metal layer deposited on at least one surface of the resin film, includes a modified layer on the surface of the resin film on which the metal layer is deposited, the modified layer having a composition different from another portion, in which the modified layer contains a metal, a metal ion, or a metal compound different from a main metal of the metal layer. The content of a metal element of the metal, the metal ion, or the metal compound on a surface of the modified layer is preferably 0.2 atomic % or more and 10 atomic % or less.

Abstract: A base film for a printed circuit board according to an embodiment of the present invention is a base film for a printed circuit board, the base film containing a polyimide as a main component. A ratio of a peak intensity around a wave number of 1705 cm?1 to a peak intensity around a wave number of 1494 cm?1 in an absorption intensity spectrum of a surface of the base film, the spectrum being measured at an angle of incidence of 45° by total reflection infrared absorption spectroscopy, is 0.50 or more and 1.10 or less. A substrate for a printed circuit board according to an embodiment of the present invention includes the base film for a printed circuit board and a metal layer stacked on the surface of the base film for a printed circuit board.

Abstract: A substrate for a printed circuit board according to an embodiment of the present invention includes a resin film and a metal layer stacked on at least one of surfaces of the resin film. An average diffusion depth of a main metal of the metal layer in the resin film is 100 nm or less after a weather resistance test in which the substrate is held at 150° C. for seven days. The average diffusion depth is preferably 80 nm or less before the weather resistance test.

Abstract: According to an embodiment of the present invention, a substrate for a printed circuit board, the substrate including a resin film and a metal layer deposited on at least one surface of the resin film, includes a modified layer on the surface of the resin film on which the metal layer is deposited, the modified layer having a composition different from another portion, in which the modified layer contains a metal, a metal ion, or a metal compound different from a main metal of the metal layer. The content of a metal element of the metal, the metal ion, or the metal compound on a surface of the modified layer is preferably 0.2 atomic % or more and 10 atomic % or less.

Abstract: An object is to provide a substrate for a printed wiring board that has good circuit formability while maintaining adhesion strength between a conductive layer (2) and a base film (1). The substrate includes a base film having an insulating property (1) and a conductive layer (2) formed on at least one surface of the base film (1). The maximum height Sz, which is defined in ISO25178, of the surface of the base film (1) is 0.05 ?m or more and less than 0.9 ?m.