Abstract: A printed circuit board according to an embodiment of the present invention, which is configured to be disposed on an inner surface of an airtight case having an opening so as to hermetically cover the opening, includes a shielding layer containing a liquid crystal polymer as a main component at least in a region covering the opening. An electronic component according to another embodiment of the present invention includes an airtight case having an opening and a printed circuit board disposed on an inner surface of the airtight case so as to hermetically cover the opening, wherein the printed circuit board includes a shielding layer containing a liquid crystal polymer as a main component at least in a region covering the opening.

Abstract: A method for producing a flexible printed circuit board according to an embodiment of the present invention includes a through-hole formation step of preparing a base material including a base film having insulating properties and flexibility and a pair of metal films stacked on both surface sides of the base film, and forming a through-hole in the metal film on a front surface side of the base material and the base film; a filling step of stacking, by electroplating on a front surface of the base material, stacking a conductive material on a surface of the metal film on the front surface side to form a conductive material layer and to fill the through-hole with the conductive material; and a removal step of removing, by etching the front surface of the base material, a surface layer of the conductive material layer stacked on the surface of the metal film on the front surface side and a surface layer of the conductive material filling the through-hole.

Abstract: (1) A conductor layer is disposed on at least one surface of a dielectric layer, the dielectric layer including an intermediate layer and a pair or more of fluororesin layers disposed on both surfaces of the intermediate layer, in which the ratio of the total average thickness of the intermediate layer to the total average thickness of the fluororesin layers is 0.001 to 30, the relative dielectric constant of the intermediate layer is 1.2 to 10, the coefficient of linear expansion of the intermediate layer is ?1×10?4/° C. to 5×10?5/° C., and the adhesive strength between the fluororesin layer and the conductor layer is 300 g/cm or more.

Abstract: A printed circuit board according to an embodiment of the present invention includes, alternately, at least one insulating layer containing a synthetic resin as a main component; and a plurality of conductive layers including circuit patterns, wherein the plurality of circuit patterns of the plurality of conductive layers form a spiral pattern in plan view, and the plurality of circuit patterns are connected together via a plurality of through-holes so as to form a single closed loop in which a current flows counterclockwise or clockwise in an entirety of the spiral pattern. The conductive layers are preferably formed on both surfaces of the at least one insulating layer so as to form a pair.

Abstract: A first embodiment of a substrate for a high-frequency printed wiring board according to the present disclosure is directed to a substrate for a high-frequency printed wiring board, the substrate including: a dielectric layer including a fluororesin and an inorganic filler; and a copper foil layered on at least one surface of the dielectric layer, wherein a surface of the copper foil at the dielectric layer side has a maximum height roughness (Rz) of less than or equal to 2 ?m, and a ratio of the number of inorganic atoms of the inorganic filler to the number of fluorine atoms of the fluororesin in a superficial region of the dielectric layer at the copper foil side is less than or equal to 0.08.

Abstract: An object of the present invention is to provide a metal powder and an ink with which a sintered body having good flexibility can be formed, and a sintered body having good flexibility. A metal powder according to an embodiment of the present invention has a mean particle size D50BET of 1 nm or more and 200 nm or less as calculated by a BET method, a mean crystallite size DCryst of 20 nm or less as determined by an X-ray analysis, and a ratio (DCryst/D50BET) of the mean crystallite size DCryst to the mean particle size D50BET of less than 0.4.

Abstract: A battery wiring module includes bus bars and a flexible wiring board having wires connected to the respective bus bars. The flexible wiring board has a body portion and extensions extending from the body portion toward the respective bus bars. Each of the extensions supports one of the wires and has an end section where a pad is arranged, that is part of each of the wires. Each of the bus bars has at least one cutout portion, and the pad is arranged on each of the bus bars such that the pad overlaps at least part of at least one cutout portion. The pad and the at least part of the at least one cutout portion are connected to each other with solder.

Abstract: A flexible printed circuit board according to an embodiment of the present invention includes at least one insulating layer having flexibility and containing a synthetic resin as a main component; and at least one conducting layer including a circuit pattern, wherein the circuit pattern includes a continuous spiral pattern, and the flexible printed circuit board includes a curved portion that curves such that one side and another side of the spiral pattern are disposed close to each other.

Abstract: The substrate for a printed circuit board according to an embodiment of the present invention includes a base film having insulating properties, and a metal layer stacked on at least one surface of the base film, in which the base film includes a portion where a transition metal in group 10 of the periodic table is present. The transition metal in group 10 is preferably nickel or palladium. The portion where the transition metal in group 10 is present preferably includes a region having an average thickness of 500 nm and extending from an interface with the metal layer.

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: An object of the present invention is to provide an adhesive composition for a printed wiring board, the adhesive composition having a good heat resistance. Another object of the present invention is to provide a coverlay for a printed wiring board, a copper-clad laminate, and a printed wiring board, all of which use the adhesive composition for a printed wiring board. The present invention provides an adhesive composition for a printed wiring board, the adhesive composition containing a siloxane-modified polyimide that includes structural units represented by formulae (1) and (2) below, an epoxy resin, and an inorganic filler. The siloxane-modified polyimide has a weight-average molecular weight (Mw) of 25,000 or more and 150,000 or less. A content of the inorganic filler is 10 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the siloxane-modified polyimide. In formulae (1) and (2), Ar represents a tetravalent aromatic tetracarboxylic acid residue, m is 0.35 or more and 0.

Abstract: A substrate for a printed circuit board according to the present invention includes a base film having an insulating property and including at least one opening; a first conductive layer that is formed on both surfaces of the base film by applying and heat-treating a conductive ink containing metal particles, and that fills the at least one opening; and a second conductive layer formed, by plating, on at least one of surfaces of the first conductive layer. The metal particles preferably have a mean particle size of 1 nm or more and 500 nm or less.

Abstract: A coating liquid for forming a conductive layer according to the present invention is a coating liquid for forming a conductive layer, the coating liquid containing fine metal particles, a dispersant, and a dispersion medium. In the coating liquid for forming a conductive layer, the fine metal particles contain copper or a copper alloy as a main component, the dispersant is a polyethyleneimine-polyethylene oxide graft copolymer, a polyethyleneimine moiety in the graft copolymer has a weight-average molecular weight of 300 or more and 1,000 or less, a molar ratio of polyethylene oxide chains to nitrogen atoms in the polyethyleneimine moiety is 10 or more and 50 or less, and the graft copolymer has a weight-average molecular weight of 3,000 or more and 54,000 or less.

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 powder for a conductive material according to an embodiment of the present invention includes a large number of particles that contain copper as a main component and having an average primary particle diameter of 1 nm or more and 200 nm or less. The particles contain titanium on surfaces or inside thereof, and a content of the titanium is 0.003 atomic percent or more and 0.5 atomic percent or less.

Abstract: A printed circuit board according to an embodiment of the present invention includes a base film having an insulating property and a conductive pattern disposed on at least one surface of the base film. The conductive pattern includes a copper particle bond layer which is fixed to the base film, and a lightness L* of a conductive pattern non-formed region of the base film is 60 or less. The base film may include a modified layer on one surface side thereof.

Abstract: A printed circuit board according to an embodiment of the present invention includes a base film containing, as a main component, a polyimide and a conductive pattern disposed on at least one surface of the base film. The conductive pattern includes a copper particle bond layer which is fixed to the base film. An external transmittance for a wavelength of 500 nm in a conductive pattern non-formed region of the base film is 70% or less of an internal transmittance for a wavelength of 500 nm in a middle layer portion of the base film.

Abstract: A flexible printed circuit board according to an aspect of the present invention includes a base film having insulating properties and a conductive pattern laminated to one surface side of the base film. The conductive pattern forms part of a circuit and includes at least one fuse portion having a cross section smaller than the other part. The conductive pattern has a pair of measurement pad portions configured to enable measurement of a potential difference between two points in the vicinity of both ends of the fuse portion.

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 base film having an insulating property, and a metal layer formed on at least one surface side of the base film. In the substrate for a printed circuit board, a plurality of fine particles are disposed between the base film and the metal layer, and the fine particles are formed of a metal the same as a main metal of the metal layer or formed of a metal compound of the main metal. The fine particles preferably have an average particle size of 0.1 nm or more and 20 nm or less. The fine particles are preferably formed of a metal oxide or a metal hydroxide. The fine particles are preferably present between the base film and the metal layer so as to form a layer. The metal layer preferably includes a metal grain layer formed by firing metal nanoparticles.