A single-layer circuit board, multi-layer circuit board, and manufacturing methods therefor. The method for manufacturing the single-layer circuit board comprises the following steps: drilling a hole on a substrate, the hole comprising a blind hole and/or a through hole; on a surface of the substrate, forming a photoresist layer having a circuit negative image; forming a conductive seed layer on the surface of the substrate and a hole wall of the hole; removing the photoresist layer, and forming a circuit pattern on the surface of the substrate, wherein forming a conductive seed layer comprises implanting a conductive material below the surface of the substrate and below the hole wall of the hole via ion implantation, and forming an ion implantation layer as at least part of the conductive seed layer.

A circuit board according to an embodiment includes an insulating layer; and a lead pattern portion disposed on the insulating layer, wherein the lead pattern portion includes: a first portion disposed on the insulating layer; and a second portion extending from one end of the first portion; wherein the first portion is disposed overlapping the insulating layer in a vertical direction, wherein the second portion is disposed in an outer region of the insulating layer and does not overlap the insulating layer; and wherein the lead pattern portion has a centerline average roughness in a range of 0.05 .Math.m to 0.5 .Math.m or a 10-point average roughness in a range of 1.0 .Math.m to 5.0 .Math.m.

A bonded substrate includes a substrate, a metal plate forming a stacked state with the substrate, and bonding member. The metal plate has a first surface on the substrate side and a second surface opposite; wherein an edge of the first surface is located outside an edge of the second. The bonding member is disposed between the substrate and plate to bond the plate and substrate, and protrudes from the edge over an entire periphery of the plate. In cut surfaces obtained by cutting the bonded substrate, a peripheral surface length (A) from a portion corresponding to a peripheral edge of the first surface to a corresponding portion of the second, protrusion length of the bonding member, and thickness (C) of the metal plate satisfy first and second expressions.
0.032≤B/(A+B)≤0.400  (First Expression)
0.5(mm)≤C≤2.0(mm)  (Second Expression)

A supported copper foil is disclosed, comprising: a poly-based film that contains polyimide and polytetrafluoroethylene; a thin copper foil; and an adhesive provided between the poly-based film and the thin copper foil, the adhesive removably coupling the poly-based film to the copper foil.

To provide a copper foil that the transmission loss is favorably controlled even when the copper foil is used in a high-frequency circuit board and that adhesion to a resin is favorable.

A copper foil including a roughened layer, and the roughened layer includes a primary particle layer, a surface roughness Ra of a surface on the side of the primary particle layer is 0.12 μm or less, and the average particle size of primary particles of the primary particle layer is 0.10 to 0.25 μm.

A metal-clad laminate includes an insulating layer including a cured product of a resin composition, and a metal foil disposed on a principal surface of the insulating layer. The resin composition includes a polyphenylene ether copolymer and a thermosetting curing agent, the polyphenylene ether copolymer having an intrinsic viscosity measured in methylene chloride at 25° C. of between 0.03 dl/g and 0.12 dl/g, inclusive. And the polyphenylene ether copolymer has, at a molecular terminal, a group represented by formula (1) or formula (2) at an average number of 1.5 to 3 per one molecule. Further, the metal foil has a first surface that is in contact with the insulating layer, the first surface having a 10-point average roughness (Rz) of 2.0 μm or less. And the metal foil includes a barrier layer disposed at a side of the first surface, the barrier layer containing cobalt. ##STR00001##

An electrical circuit board includes a first conductive layer and a second conductive layer. And an interlayer forming a thermal barrier is placed between the first conductive layer and the second conductive layer, wherein the thermal barrier reduces heat transfer between the first conductive layer and the second conductive layer.

A wiring substrate is manufactured by attaching an adhesive protective film to a metal-foiled laminate sheet, forming bottomed via holes by partially removing the film and an insulating film, filling conductive pastes into the holes, and peeling the film. A wiring substrate is manufactured by forming an adhesive protective layer so as to cover a patterned metal foil on a metal-foiled laminate sheet, forming bottomed step via holes by partially removing the layer and an insulating film, filling conductive pastes into the holes, and peeling off a protective film. The wiring substrate and the second wiring substrate are laminated in such a way that protruding parts of the pastes come into contact with respective protruding parts of the pastes.

A free grounding film and a manufacturing method therefor, and a shielding circuit board including the free grounding film and a grounding method. The free grounding film includes at least one conductor layer. The shielding circuit board including the free grounding film is formed in a manner that an electromagnetic wave shielding film is arranged on a printed circuit board, and the upper surface of the electromagnetic wave shielding film is provided with the free grounding film. The grounding method for the shielding circuit board adopts one of three modes.

A method for producing a printed circuit board (13, 15, 16) with multilayer subareas in sections, characterized by the following steps: a) providing at least one conducting foil (1, 1′) and application of a dielectric insulating foil (3, 3′) to at least one subarea of the conducting foil; b) applying a structure of conducting paths (4, 4′) to the insulating layer (3, 3′); c) providing one further printed circuit board structure; d) joining of the further printed circuit board structure with the conducting foil (1, 1′) plus insulating layer (3, 3′) and conducting paths (4, 4′) by interposing a prepreg layer (5, 85; 18, 18′), and e) laminating the parts joined in step d) under pressing pressure and heat; and a printed circuit board produced according to this method.