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.

A method of manufacturing a printed circuit board includes forming an intermediate layer on a first conductive layer disposed on a first insulating layer, forming a second conductive layer and a second insulating layer on the intermediate layer, separating the first insulating layer from at least one portion of the first conductive layer, and etching the first conductive layer and the intermediate layer. After the etching, a surface of the second conductive layer protrudes further than a surface of the second insulating layer. The intermediate layer before the etching includes a portion overlapping the second conductive layer in a vertical direction and another portion not overlapping the second conductive layer in the vertical direction.

A multilayer substrate and a manufacturing method thereof are disclosed. The multilayer substrate includes two or more dielectric layers laminated in sequence; a public line disposed at a top or bottom dielectric layer of the two or more dielectric layers; and two or more first through hole pillars respectively each embedded in a respective one of the dielectric layers, and the first through hole pillars are connected in cascade and then connected with the public line.

A printed circuit board includes: an insulating layer including a cavity formed therein, the cavity being recessed into the insulating layer from a top surface of the insulating layer; a first circuit layer formed inside the insulating layer such that a portion of the first circuit layer is disposed within the cavity; a second circuit layer disposed above the insulating layer; a first surface-treated layer disposed above the portion of the first circuit layer disposed within the cavity; and a second surface-treated layer disposed above the second circuit layer.

In a method for producing a wired circuit board includes a step (1), in which the insulating layer having an inclination face is provided; a step (2), in which a metal thin film is provided on the surface of the insulating layer including the inclination face; a step (3), in which a photoresist is provided on the surface of the metal thin film; a step (4), in which a photomask is disposed so that a first light exposure portion and a second light exposure portion in the photoresist are exposed to light, and the photoresist is exposed to light; a step (5), in which the first light exposure portion and the second light exposure portion are removed; and a step (6), in which the first wire and the second wire are provided on the surface of the metal thin film.

A high frequency signal transmission structure includes an insulating sheet and a conductive wiring layer forming on the insulating sheet. The conductive wiring layer includes a silver conductive layer forming on the insulating sheet, a copper conductive layer forming on the silver conductive layer, and a silver covering layer covering a top surface and side surfaces of the copper conductive layer. The silver conductive layer and the silver covering layer together surround the copper conductive layer.

A method of plating a copper substrate with gold that reduces or eliminates the presence of microvoids at the interface of the gold/copper substrate is described. Suitably, live entry of the substrate into the plating bath is performed with application of external current to the bath such that no portion of the substrate is exposed to the bath for more than one second without the application of the external current. Increase of the applied current for gold strike to the mass-transfer-limit for gold reduction accomplishes the full measure of improvement in eliminating microvoids.

Disclosed is a circuit board having a contact pad for connection with an external device, which protrudes from an upper surface of an outermost insulating layer. A device can be mounted on the circuit board, and a connection terminal of the device can be connected to the contact pad of the circuit board by a wire etc.

A method for fabricating a conductive trace structure includes the steps: forming a first metal layer on a non-conductive substrate; removing a part of the first metal layer to expose the non-conductive substrate so as to form the first metal layer into a plating region and a non-plating region, the plating region being divided into at least two trace-forming portions and at least one bridge portion; forming a second metal layer on the plating region by electroplating the plating region using one of the trace-forming portions and the bridge portion as an electrode; and removing the bridge portion and the second metal layer formed on the bridge portion.

A method for manufacturing a component carrier includes covering a dielectric layer structure by a metal foil, forming an electroless metal layer on the metal foil, and forming a multi-stage electroplating structure on the electroless metal layer. A component carrier made by the method is further described.