A printed circuit board includes an insulating layer; a recess portion disposed on one surface of the insulating layer; and a circuit layer disposed on the one surface of the insulating layer and including a signal pattern and a ground pattern. At least a portion of the ground pattern covers at least a portion of the recess portion.

A method for manufacturing a printed wiring board includes forming through holes in a double-sided copper-clad laminated plate such that a high-density region of the through holes and a low-density region of the through holes are formed, forming an electrolytic plating film on a copper foil of the plate in the high-density and low-density regions, forming a masking resist to mask the plating film in the high-density region, etching the plating film in the low-density region exposed from the resist such that the plating film in the low-density region is thinned, peeling off the resist from the plating film in the high-density region, and forming a conductor circuit including the copper foil and the plating film in the high-density and low-density regions. The forming of the plating film on the copper foil of the plate includes forming the plating film in the through holes in the high-density and low-density regions.

A component carrier includes a layer body with at least one electrically conductive layer structure and/or at least one electrically insulating layer structure, a component embedded in the layer body, and at least one galvanic connection stack at least partially on at least part of at least one main surface of the layer body. At least one of a bottom main surface and a top main surface of the embedded component is electrically connected to the at least one galvanic connection stack.

A component carrier includes an electrically insulating layer structure having a first main surface and a second main surface with a through hole extending through the electrically insulating layer structure between the first main surface and the second main surface. An electrically conductive bridge structure connects opposing sidewalls of the electrically insulating layer structure delimiting the through hole. A vertical thickness of the electrically insulating layer structure is not more than 200 μm and a narrowest vertical thickness of the bridge structure is at least 20 μm.

A method for forming a circuit board having a dielectric core, a foil top surface, and a thin foil bottom surface with a removable foil backing of sufficient thickness to absorb heat from a laser drilling operation to prevent the penetration of the thin foil bottom surface during laser drilling utilizes a sequence of steps including a laser drilling step, removing the foil backing step, electroless plating step, patterned resist step, electroplating step, resist strip step, tin plate step, and copper etch step, which provide dot vias of fine linewidth and resolution.

A component carrier includes a stack with at least one electrically conductive layer structure, at least one electrically insulating layer structure, and a hole in the stack having a first hole portion covered with metal and having a second hole portion not covered with metal, wherein the second hole portion is defined by an anti-plating dielectric structure and an electroless plateable separation barrier.

A method for manufacturing a wiring substrate includes preparing a substrate including an insulating layer and metal foils, forming a through hole in the substrate to penetrate through the insulating layer and foils, forming a first plating film on the substrate such that the first film is formed on the entire surface of each metal foil and the inner wall of the hole, laminating one or more resin sheets on the first film such that the resin sheet or sheets cover the first film on the entire surface of a respective one of the foils, pressing the resin sheet or sheets such that resin is extruded from the resin sheet or sheets into the hole and fills space surrounded by the first film inside the hole, removing the resin sheet or sheets, and forming a second plating film on the substrate to cover surface of the resin in the hole.

A wiring board includes a core layer having a first through hole formed therein, a magnetic resin filled inside the first through hole, a second through hole formed in the magnetic resin, and a plating film covering an inner wall surface of the second through hole. The plating film includes an electroless plating film, and an electrolytic plating film. The electroless plating film makes direct contact with an inner wall surface of the second through hole.

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 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.