A method for manufacturing a wiring board is capable of forming a metal layer included in a wiring layer to have an even thickness. The method includes preparing a conductive first underlayer on a surface of a substrate; a conductive second underlayer on a surface of the first underlayer; and a seed layer on a surface of the second underlayer and containing metal. The method disposes a solid electrolyte membrane between an anode and the seed layer as a cathode; applies voltage between the anode and the first underlayer to form a metal layer on the surface of the seed layer; removes an exposed portion of the second underlayer without the seed layer from the substrate; and removes an exposed portion of the first underlayer without the seed layer from the substrate. The first underlayer is a material having a higher electrical conductivity than that of the second underlayer.

A printed wiring board includes a base layer having insulating properties, a first conductive layer directly or indirectly stacked on the base layer front surface, and including a copper foil, a second conductive layer directly or indirectly stacked on the base layer back surface, and including a copper foil, a stacked body for a via hole, the stacked body being stacked on an inner periphery and a bottom of a connection hole that extends through the first conductive layer and the base layer in a thickness direction, and being configured to electrically connect the first conductive layer and the second conductive layer to each other, and having an electroless copper plating layer. Each copper foil contains a copper crystal grain oriented in a plane orientation, and an average crystal grain size of copper of each copper foil is 10 μm or greater, the electroless copper plating layer includes palladium.

A manufacturing method of copper foil and circuit board assembly for high frequency transmission are provided. Firstly, a raw copper foil having a predetermined surface is produced by an electrolyzing process. Subsequently, a roughened layer including a plurality of copper particles is formed on the predetermined surface by an arsenic-free electrolytic roughening treatment and an arsenic-free electrolytic surface protection treatment. Thereafter, a surface treatment layer is formed on the roughened layer, and the roughened layer is made of a material which includes at least one kind of non-copper metal elements and the concentration of the non-copper metal elements is smaller than 400 ppm. By controlling the concentration of the non-copper elements, the resistance of the copper foil can be reduced.

A wiring substrate includes a first conductor layer, an insulating layer formed on the first conductor layer, a second conductor layer formed on the insulating layer, a connection conductor penetrating through the insulating layer and connecting the first and second conductor layers, and a coating film formed on a surface of the first conductor layer and adhering the first conductor layer and the insulating layer. The first conductor layer includes a conductor pad in contact with the connection conductor such that the conductor pad has a surface having a first region and a second region on second conductor layer side and that surface roughness of the first region is different from surface roughness of the second region, and the conductor pad of the first conductor layer is formed such that the first region is covered by the coating film and that the second region is covered by the connection conductor.

A method for producing a structure, comprising providing a Composite Conductive Substrate (CCS) with a conductive layer, a non-conductive layer and a release layer, implemented on top of the conductive layer; determining an empty conductive pattern for each layer of the structure; printing a layer of non-conductive matter on the CCS, such that the conductive pattern of the first layer left empty from the non-conductive matter; on top of the release layer, below which the conductive layer is implemented, filling the empty conductive pattern with conductive matter by electroplating; peeling the filled conductive matter or peeling the filled conductive matter and the printed non-conductive matter, from the conductive layer of the CCS.

A method for forming a metal film includes forming an oxide layer on a to-be-treated surface of a to-be-treated object by bringing the to-be-treated surface into contact with a reaction solution containing fluorine and an oxide precursor, removing fluorine in the oxide layer, supporting a catalyst on the oxide layer by bringing the oxide layer into contact with a catalyst solution, and depositing a metal film on the oxide layer by bringing the oxide layer into contact with an electroless plating liquid.

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 μm or greater to 50 μm or smaller, and an average thickness of the second conductive portion is 1 μn or greater to smaller than 8.5 μm.

A wiring board includes an insulating base including a first principal surface, a second principal surface opposite to the first principal surface, and a first through hole penetrating the insulating base from the first principal surface to the second principal surface, a functional material provided inside the first through hole, a first insulating layer covering the first principal surface, and a first surface of the functional material, and a second insulating layer covering the second principal surface, and a second surface of functional material. A second through hole is formed in the first insulating layer, the functional material, and the second insulating layer, and a conductive layer is formed on a wall surface of the second through hole.

Disclosed is a method for manufacturing a wiring structure including a step of forming a wiring on an insulating resin layer. The step of forming the wiring includes: forming a modified region including pores in a surface layer of the insulating resin layer by treating a surface of the insulating resin layer with a treatment method including surface modification; forming a seed layer on the surface of the insulating resin layer by sputtering; and forming the wiring on the seed layer by electrolytic copper plating. The disclosed method may include, in this order: a step of forming a surface treatment agent layer that covers a surface of the wiring by treating the surface of the wiring with a surface treatment agent for improving adhesion; and a step of forming a modified region including pores in a surface layer of a first layer of the insulating resin layer by treating the surface of the first layer of the insulating resin layer with a treatment method including surface modification.

In a plating method, a laminate made of stainless steel, and copper or a copper alloy is prepared. Plating underlayers made of nickel are formed on a first plated portion provided at the stainless steel and a second plated portion provided at the copper or the copper alloy at the same time with use of a hydrochloric acid electrolytic solution.