Abstract: A flexible printed circuit board according to an embodiment includes a base film and a first wire. The base film has a first surface. The first wire is disposed on the first surface. The first wire has a first layer and a second layer. The first layer is disposed on the first surface directly or indirectly. The second layer covers the first layer. In the first surface, a first groove is formed next to the first layer in a plan view. The second layer on a side surface of the first layer exists on a bottom surface and a side surface of the first groove.

Abstract: A flexible printed circuit board includes: a base film having a hole for forming a through hole; and a coil-shaped wiring layer layered on at least one surface side of the base film, wherein the wiring layer includes a land portion arranged at an inner peripheral surface of the hole and at a peripheral portion of the hole of the base film, and a winding portion arranged in a spiral shape with the land portion as an inside end portion or an outside end portion, wherein the winding portion includes a first winding portion that is an outermost circumference and a second winding portion that is inside relative to the outermost circumference, and wherein a ratio of an average thickness of the land portion to an average thickness of the second winding portion is 1.1 or more and 5 or less.

Abstract: A printed wiring board includes a base film having a main surface, a coil wiring formed on the main surface, and a first connection land and a second connection land connected to one end and another end of the coil wiring, respectively. The main surface includes a first main surface and a second main surface opposite to the first main surface. The coil wiring includes a first coil wiring formed in a spiral shape on the first main surface, and a second coil wiring formed in a spiral shape on the second main surface and electrically connected to the first coil wiring. The first connection land and the second connection land are formed on the second main surface. The number of turns of the first coil wiring is more than the number of turns of the second coil wiring.

Abstract: A flexible printed circuit board includes a base film having an insulating property, and one or more interconnects laminated to at least one surface side of the base film. At least one of the one or more interconnects includes, in a longitudinal direction, a first portion and a second portion that is a portion other than the first portion, an average thickness of the second portion being greater than an average thickness of the first portion. A ratio of the average thickness of the second portion to the average thickness of the first portion is greater than or equal to 1.5 and less than or equal to 50.

Abstract: The printed circuit board includes, a first conductive layer including copper foil, an insulating base layer, and a second conductive layer including copper foil in this order, and includes a via-hole laminate that is stacked on an inner circumference and a bottom of a connection hole extending through the first conductive layer and the base layer in a thickness direction. The via-hole laminate has an electroless copper plating layer stacked on the connection hole and an electrolytic copper plating layer stacked on the electroless copper plating layer. The copper foil has copper crystal grains oriented in a (100) plane orientation, and an average crystal grain size of copper of 10 ?m or more. The electroless copper plating layer includes palladium and tin, and an amount of the palladium stacked per unit area of a surface of the copper foil is 0.18 ?g/cm2 or more and 0.40 ?g/cm2 or less.

Abstract: A flexible printed circuit board according to an aspect is a flexible printed circuit board including a base film and a wiring layer disposed on at least one surface of the base film and having a plurality of wiring lines. The wiring lines have an average line width of 30 ?m or less and an average spacing of 30 ?m or less. The wiring lines have a copper-based plating layer. The copper-based plating layer has an electrical resistivity of more than 1.68×10?8 ?·m.

Abstract: A printed wiring board includes a base film having a first surface and a second surface opposite to the first surface, a first electrically conductive pattern existing on the first surface, and a first electrically insulating layer existing on the first surface so as to cover the first electrically conductive pattern. A plurality of first voids exist in the first electrically insulating layer.

Abstract: A flexible printed circuit board includes: an electrically insulating layer having a first surface and a second surface opposite to the first surface; a first wiring disposed on the first surface; a second wiring disposed on the second surface; and an electrically conductive layer. The first wiring includes a first land. The second wiring includes a second land. The first wiring includes a first layer disposed on the first surface and a second layer disposed on the first layer. The second wiring includes a third layer disposed on the second surface and a fourth layer disposed on the third layer. The first land and the second land overlap each other in a plan view. The electrically insulating layer is provided with a through hole extending through the electrically insulating layer in a thickness direction and overlapping the first land and the second land at least partially in the plan view.

Abstract: A high-frequency circuit includes a first dielectric layer, a circuit layer, a second dielectric layer arranged in this order, the circuit layer includes a transmission line of a high-frequency signal and a ground pattern disposed around the transmission line. An electromagnetic wave shield is disposed in the first dielectric layer and the second dielectric layer around the transmission line. The electromagnetic wave shield includes a first ground electric conductor formed on an inner surface of at least one first hole formed to extend through the first dielectric layer without extending through the ground pattern, and a second ground electric conductor formed on an inner surface of at least one second hole formed to extend through the second dielectric layer without extending through the ground pattern. The first ground electric conductor and the second ground electric conductor are each electrically connected to the ground pattern.

Abstract: A planar coil element of the present invention includes an insulating base film having a first surface and a second surface opposite to the first surface, a first conductive pattern deposited on the first surface side of the insulating base film, and a first insulating layer covering the first conductive pattern on the first surface side, in which the first conductive pattern includes a core body and a widening layer deposited by plating on the outer surface of the core body, the core body includes a thin conductive layer on the insulating base film, and the ratio of the average thickness of the first conductive pattern to the average circuit pitch of the first conductive pattern is 1/2 or more and 5 or less.

Abstract: A base material for a printed circuit board includes: an insulating base film; and a sintered body layer of metal particles layered on one side surface of the base film; wherein an arithmetic mean roughness (Sa) of a surface of the sintered body layer that is opposite to the base film is greater than or equal to 0.005 ?m and less than or equal to 0.10 ?m.

Abstract: A substrate for a printed wiring board includes a base layer, and a copper foil directly or indirectly stacked on at least a part of one or both surfaces of the base layer. The base layer includes a matrix containing a fluororesin as a main component and one or more reinforcing material layers included in the matrix, and a ratio B/A is 0.003 to 0.37, where A is an average thickness of the base layer, and B is an average distance between a surface of the copper foil facing the matrix and a surface of a reinforcing material layer closest to the surface of the copper foil facing the copper foil.

Abstract: A flexible printed circuit board includes a base film having an insulating property, and multiple interconnects laminated to at least one surface side of the base film. The multiple interconnects include a first interconnect and a second interconnect in a same plane. An average thickness of the second interconnect is greater than an average thickness of the first interconnect. A ratio of the average thickness of the second interconnect to the average thickness of the first interconnect is greater than or equal to 1.5 and less than or equal to 50.

Abstract: A printed wiring board includes: a board having a through-hole; a land portion that is disposed on an inner circumferential surface of the through-hole and on a surface of the board at a circumferential edge of the through-hole, and that has a through-hole conductor portion; and a wire that is disposed on the surface of the board and that has one longitudinal end portion electrically connected to the land portion, a maximum length of a connection portion between the wire and the land portion being greater than or equal to a sum of a maximum diameter of the through-hole and a minimum line width of the wire.

Abstract: A printed wiring board production method that forms a base film and a conductive pattern on the base film by an additive method or a subtractive method, includes a plating process that electroplates the conductive pattern on a surface of the base film, wherein the plating process includes a shield plate arranging process that arranges a shield plate between an anode and a printed wiring board substrate that forms a cathode, and a substrate arranging process that arranges the printed wiring board substrate in a plating tank, and wherein a distance between the shield plate and the printed wiring board substrate is 50 mm or greater and 150 mm or less.

Abstract: A flexible printed circuit board according to the present disclosures includes a base film having an insulating property, and a planar coil disposed on a surface of the base film, wherein a number of turns on an inside of a center point of a coil width of the planar coil in a plan view is greater than a number of turns on an outside of the center point.

Abstract: A flexible printed circuit board includes a base film having an insulating property, and multiple interconnects laminated to at least one surface side of the base film. The multiple interconnects include a first interconnect and a second interconnect in a same plane. An average thickness of the second interconnect is greater than an average thickness of the first interconnect. A ratio of the average thickness of the second interconnect to the average thickness of the first interconnect is greater than or equal to 1.5 and less than or equal to 50.

Abstract: A printed wiring board according to an aspect of the present invention includes a base film having insulation properties and a conductive pattern including multiple wiring portions laminated, the conductive pattern running on at least one surface of the base film, wherein each wiring portion includes a first conductive portion and a second conductive portion coating an outer surface of the first conductive portion, wherein an average width of each wiring portion is 10 ?m or greater to 50 ?m or smaller, and an average thickness of the second conductive portion is 1 ?n or greater to smaller than 8.5 ?m.

Abstract: A method for manufacturing a printed circuit board according to one embodiment of the present invention includes a step of forming a resist pattern, and a step of forming a conductive pattern by using the resist pattern. The resist pattern has an acute angle portion in which an outer edge of a resist is bent to form an acute angle in a plan view. In a corner portion of the acute angle portion, an outer-side outer edge of the resist is rounded, and a radius of curvature of the outer-side outer edge is more than or equal to a distance from the outer-side outer edge to another outer edge adjacent thereto in a direction away from a center of curvature of the outer-side outer edge.

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.