Patent ID: 8362367

Claim:
A multilayer printed wiring board, comprising: a first insulative material; a first conductive circuit formed on the first insulative material; an insulative thin film formed on a surface of the first conductive circuit, including side surfaces of the first conductive circuit, and not formed on a portion of the surface to which a via conductor is connected; a second insulative material formed on the first insulative material and the first conductive circuit such that the insulative thin film is interposed between the second insulative material and the first conductive circuit, the second insulative material having an opening portion that reaches the first conductive circuit such that a surface of the first conductive circuit is exposed through the opening portion; a second conductive circuit formed on the second insulative material, wherein the via conductor being formed in the opening portion and connecting the first conductive circuit and the second conductive circuit, such that the via conductor is directly connected to the surface of the first conductive circuit exposed through the opening portion; a soldering connection layer that is mechanically and electrically coupled to a surface of the second conductive circuit; and a solder bump formed on the soldering connection layer, wherein the solder bump is electrically coupled to the second conductive circuit.