A printed circuit board includes an insulating layer, a circuit pattern on the insulating layer, and a surface treatment layer on the circuit pattern. The surface treatment layer includes a bottom surface having a width wider than a width of a top surface of the circuit pattern.

A printed circuit board includes a first insulating layer; a pad disposed on the insulating layer and having a protrusion; and a protective layer disposed on the insulating layer and having an opening exposing at least a portion of the pad. The protrusion protrudes from one surface of the pad and is buried in at least one of the insulating layer and the protective layer.

A wiring substrate device includes a wiring substrate, a plurality of terminals each of which is provided upright on the wiring substrate and has a lower end, an upper end and a narrowed part between the lower end and the upper end, and a plurality of solders each of which has a melting point lower than the terminals and covers a surface of the corresponding terminal.

A circuit board structure includes a substrate, a third dielectric layer, a fourth dielectric layer, a first external circuit layer, a second external circuit layer, a conductive through hole electrically connected to the first and second external circuit layers, a first annular retaining wall surrounding the conductive through hole, and a second annular retaining wall surrounding the conductive through hole. The first annular retaining wall is electrically connected to the first external circuit layer and a first inner circuit layer. The second annular retaining wall is electrically connected to the second external circuit layer and a second inner circuit layer. A first ground circuit, the first annular retaining wall, and the first inner circuit layer define a first ground path surrounding a first signal circuit. A second ground circuit, the second annular retaining wall, and the second inner circuit layer define a second ground path surrounding a second signal circuit.

Provided is a method for manufacturing a wiring board that forms a wiring layer having favorable adhesion without a resin resist pattern. A method prepares a substrate with seed-layer including: a underlayer on the surface of an insulating substrate; and a seed layer on the surface of the underlayer, the seed layer having a predetermined pattern and containing metal; presses a solid electrolyte membrane against the seed layer and the underlayer, and applies voltage between an anode and the underlayer to reduce metal ions in the membrane and form a metal layer on the surface of the seed layer; and removes an exposed region without the seed layer and the metal layer of the underlayer to form a wiring layer including the underlayer, the seed layer and the metal layer on the surface of the substrate.

Apparatuses and methods are provided for mitigating radio frequency interference and electromagnetic compatibility issues caused by the resonance of metal planes of a circuit board. A method for controlling impedance at an edge of a circuit board includes creating a cut at an edge of a plane of the circuit board. The cut extends from the edge of the plane to a point at a depth into the plane. The method can further include creating a cut pattern in the edge of the plane by repeating the cut along the edge of the plane such that an impedance of the plane at the depth is different, or lower, than an impedance of the plane at the edge of the plane. Other aspects are described.

A printed circuit board includes an insulating layer, a circuit pattern on the insulating layer, and a surface treatment layer on the circuit pattern. The surface treatment layer includes a bottom surface having a width wider than a width of a top surface of the circuit pattern.

A wiring substrate includes: an insulating substrate comprising a principal face; a wiring line located on the principal face; and a protruding portion on a side of the wiring line, the protruding portion being smaller in thickness than the wiring line and protrudes from the side along the principal face.

A compact electronic device for wireless communication is disclosed. The compact electronic device includes a main printed circuit board, one or more antennas, at least one conductor, and a shell. The one or more antennas are configured for wireless communication. The at least one conductor being configured to provide at least one of control signals and power to a fan. The shell mounts the fan relative to the main printed circuit board. The shell includes walls forming a cavity. The walls encapsulate the conductor in the cavity.

A printed wiring board includes a first insulating layer, a conductor layer, and a second insulating layer. The conductor layer includes first and second circuits such that space is formed between the circuits, the first circuit has first and second side walls, the second circuit has third and fourth side walls such that the second wall faces the third wall, the first circuit has first, second and third portions, the second circuit has fourth, fifth and sixth portions such that the first and fourth portions, the second and fifth portions and the third and sixth portions face each other, the first circuit is formed such that the second wall of the second portion is recessed from the second wall of the first and third portions, and the first insulating layer has recess between the second and fifth portions such that the second insulating layer is filling the space and recess.