A method for manufacturing conductive lines is provided. A first metal layer is formed over a carrier substrate. A second metal layer is formed over the first metal layer. A plurality of first conductive lines is formed on the second metal layer. A protective layer is formed on opposite sidewalls of the first conductive lines. An exposed portion of the second metal layer is removed to expose a portion of the first metal layer. The exposed portion of the first metal layer is removed, and the protective layer is removed.

A three-dimensional wiring board production method is provided that includes: a preparation step of preparing a resin film having a breaking elongation of 50% or more; a first metal film formation step of forming a first metal film on a surface of the resin film; a pattern formation step of performing patterning on the first metal film to form a desired pattern; a three-dimensional molding step of performing three-dimensional molding by heating and pressurizing the resin film; and a second metal film formation step of forming a second metal film on the first metal film having a pattern formed thereon. In the first metal film formation step, metal is deposited in a particle state to form the first metal film in a porous state.

A manufacturing method of a composite substrate is provided. A first conductive layer is formed on a first liquid crystal polymer layer. The first conductive layer is patterned to form a patterned first conductive layer. A second liquid crystal polymer layer including a soluble liquid crystal polymer is formed to cover the patterned first conductive layer. The second liquid crystal polymer layer which is on the patterned first conductive layer is removed.

A multi-layer circuit board capable of being applied with electrical testing includes a patterned metal-interface layer, a metallic delivery loading plate, an electrical connection layer, a conductive corrosion-barrier layer, a bottom dielectric layer, and a multi-layer circuit structure. The multi-layer circuit structure is disposed on the delivery loading plate through the bottom dielectric layer. The top-layer circuit of the multi-layer circuit structure is electrically connected to the conductive corrosion-barrier layer through the bottom-layer circuit and the electrical connection layer. The delivery loading plate and the patterned metal-interface layer expose the conductive corrosion-barrier layer. Therefore, before the multi-layer circuit board is packaged, an electrical testing can be applied to the multi-layer circuit board to check if it can be operated normally. Hence, costs for figuring out reasons of the unqualified electronic component can be reduced, and responsibilities for the unqualified electrical testing result of the electronic component can be clarified.

An electroconductive substrate, including: a base material; a foundation layer disposed on the base material; a trench formation layer disposed on the foundation layer, and an electroconductive pattern layer including metal plating. A trench including a bottom surface to which the foundation layer is exposed, is formed. The trench is filled with the electroconductive pattern layer. The foundation layer includes a mixed region which is formed from a surface of the foundation layer on the electroconductive pattern layer side towards the inside thereof, and contains metal particles which contain a metal configuring the electroconductive pattern layer, and enter the foundation layer.

A flexible printed circuit board with reduced ion migration from signal-carrying elements which are coated against corrosion includes an insulating layer, a wiring area, a copper electroplating layer, a nickel electroplating layer, a cover film, and a gold chemical-plating layer. The wiring area is formed on the insulating layer. The copper electroplating layer formed on the wiring area has a first portion and a second portion. The nickel electroplating layer is formed on at least the first portion and exposes sidewalls of the first portion. The cover film is formed on the second portion and fills in gaps of the copper electroplating layer. The gold chemical-plating layer is formed on top surface of the nickel electroplating layer and the sidewalls of the first portion.

A layered structure, an article such as circuit board including such a layered structure, and methods of making the same are provided. The layered structure includes a substrate comprising glass or glass ceramic, an adhesion layer disposed on the substrate, a seed layer disposed on the adhesion layer, a first conductive layer disposed on the seed layer, and a second conductive layer disposed on the first conductive layer. The seed layer includes a first metal material and has a first type of stress with respect to the substrate. The first conductive layer includes the first metal material and has a second type of stress with respect to the substrate. The second conductive layer includes a second metal material and has the first type of stress with respect to the substrate. The layered structure may further include additional pairs of alternating layers of the first and the second conductive layers.

A flexible printed circuit board with reduced ion migration from signal-carrying elements which are coated against corrosion includes an insulating layer, a wiring area, a copper electroplating layer, a nickel electroplating layer, a cover film, and a gold chemical-plating layer. The wiring area is formed on the insulating layer. The copper electroplating layer formed on the wiring area has a first portion and a second portion. The nickel electroplating layer is formed on at least the first portion and exposes sidewalls of the first portion. The cover film is formed on the second portion and fills in gaps of the copper electroplating layer. The gold chemical-plating layer is formed on top surface of the nickel electroplating layer and the sidewalls of the first portion.

A flexible printed circuit board with reduced ion migration from signal-carrying elements which are coated against corrosion includes an insulating layer, a wiring area, a copper electroplating layer, a nickel electroplating layer, a cover film, and a gold chemical-plating layer. The wiring area is formed on the insulating layer. The copper electroplating layer formed on the wiring area has a first portion and a second portion. The nickel electroplating layer is formed on at least the first portion and exposes sidewalls of the first portion. The cover film is formed on the second portion and fills in gaps of the copper electroplating layer. The gold chemical-plating layer is formed on top surface of the nickel electroplating layer and the sidewalls of the first portion.

A metal circuit structure based on a flexible printed circuit (FPC) contains: a substrate, a first metal layer attached on the substrate, a second metal layer formed on the first metal layer, and an intermediate layer defined between the first metal layer and the second metal layer. A first surface of the intermediate layer is connected with the first metal layer, and a second surface of the intermediate layer is connected with the second metal layer. The intermediate layer is made of a first material, the second metal layer is made of a second material, and the first material of the intermediate layer does not act with the second material of the second metal layer.