Patent ID: 8134080

Claim:
A wired circuit board comprising: a metal supporting board; an insulating layer made of resin and formed on the metal supporting board; a conductive pattern formed on the insulating layer; and a metal foil embedded in the insulating layer such that the metal foil is separated from the conductive pattern by the insulating layer and the conductive pattern is opposed to the metal foil, wherein an opening confronting at least a part of the conductive pattern is formed in and surrounded by the metal supporting board, wherein at least a part of the metal foil is placed in the opening and exposed from the insulating layer not to overlap with a marginal portion of the opening such that a gap is formed between a peripheral edge of the part of the metal foil placed in the opening and the opening in the metal supporting board, wherein the gap surrounds the part of the metal foil placed in the opening, wherein at least a part of the marginal portion of the opening of the metal supporting board is put in direct contact with the insulating layer such that an enhanced adhesion between the metal supporting board and the insulating layer is provided at the marginal portion of the opening, and wherein the opening having the part of the metal foil placed therein is operative to adjust a characteristic impedance of the conductive pattern and reduce transmission loss of the conductive pattern.