The present disclosure provides a flexible circuit board. The flexible circuit board includes a substrate; a conductive layer, disposed on the substrate; and a cover layer, disposed on a side of the conductive layer facing away from the substrate. The flexible circuit board is provided with a through hole penetrating through the flexible circuit board in the thickness direction. The cover layer includes a hollowed-out region located at least at an edge of one side of the through hole. The conductive layer includes an electrostatic discharge section exposed in the hollowed-out region.

A printed circuit board includes: a first insulating layer; a first wiring layer at least partially buried in the first insulating layer; a second insulating layer disposed on an upper surface of the first insulating layer; a second wiring layer at least partially buried in the second insulating layer; and a cavity penetrating through the second insulating layer and a portion of the first insulating layer and exposing a portion of the upper surface of the first insulating layer as a bottom surface of the cavity. The first wiring layer includes a wiring pattern at least partially exposed from the first insulating layer by the cavity, an upper surface of the wiring pattern has a step structure with the upper surface of the first insulating layer exposed by the cavity, and a lower surface of the wiring pattern is coplanar with a lower surface of the first insulating layer.

A printed circuit board includes: a first insulating layer; a first wiring layer at least partially buried in the first insulating layer; a second insulating layer disposed on an upper surface of the first insulating layer; a second wiring layer at least partially buried in the second insulating layer; and a cavity penetrating through the second insulating layer and a portion of the first insulating layer and exposing a portion of the upper surface of the first insulating layer as a bottom surface of the cavity. The first wiring layer includes a wiring pattern at least partially exposed from the first insulating layer by the cavity, an upper surface of the wiring pattern has a step structure with the upper surface of the first insulating layer exposed by the cavity, and a lower surface of the wiring pattern is coplanar with a lower surface of the first insulating layer.

The present disclosure provides a flexible circuit board. The flexible circuit board includes a substrate; a conductive layer, disposed on the substrate; and a cover layer, disposed on a side of the conductive layer facing away from the substrate. The flexible circuit board is provided with a through hole penetrating through the flexible circuit board in the thickness direction. The cover layer includes a hollowed-out region located at least at an edge of one side of the through hole. The conductive layer includes an electrostatic discharge section exposed in the hollowed-out region.

A laminate contains conductive circuit patterns, a substrate material, and an adhesive pattern or other bond. Each conductive circuit pattern and the substrate material are interconnected by the adhesive pattern or other bond, having its size and shape substantially matching the main outlines of each conductive circuit pattern. Each conductive circuit pattern has thin lines and thin interline spaces, patterned on top of the adhesive pattern or other bond by a removal of conductive material, such that the circuit pattern's thin interline spaces may have residues of the adhesive patterns or other bond. Outside the conductive circuit patterns' main outlines, the substrate material is substantially void of an adhesive or other bond, with the exception of edge areas of the main outlines.

Provided is an embedded printed circuit board, including: a first insulating substrate including a first cavity and a second cavity; a first element disposed in the first cavity; an adhesive layer for adhering the first insulating substrate to the first element and including an opening to which the first element is exposed; and an second insulating substrate forming a bonding layer of a lower surface of the first insulating substrate and a bottom surface of the second cavity.

A layered body is manufactured by etching a first foil constituting a three-layer metal foil to form a first metal layer shaped like a pattern, stacking a first insulating layer so as to bury the first metal layer, forming a first via as a plated via, forming a second metal layer shaped like a pattern on the first insulating layer, stacking a second insulating layer so as to bury the second metal layer, removing a second foil and a third foil constituting the three-layer metal foil, stacking a third insulating layer and a resin film on the second insulating layer, and providing a second via as a paste via to the second insulating layer, and a multilayer substrate is obtained by stacking a plurality of layered bodies.