Patent ID: 7985930

Claim:
A multi-layer printed circuit board comprising: a core structure comprising a plurality of resin layers and a metal layer sandwiched by the resin layers, the core structure having a first surface and a second surface on an opposite side of the first surface; a first conductor layer comprising a plurality of conductor circuits formed on the first surface of the core structure; and a second conductor layer comprising a plurality of conductor circuits formed on the second surface of the core structure, wherein the metal layer of the core structure comprises a plurality of conductor circuits, the core structure includes a first via hole and a second via hole, and the first via hole and the second via hole comprise a metal filling up to the respective top of a plurality of openings formed in the plurality of resin layers, respectively, sandwich at least one of the conductor circuits of the metal layer in the core structure, taper toward the conductor circuits sandwiched by the resin layers in the core structure and are positioned vertically to form a through hole electrically connecting respective ones of the conductor circuits of the first and the second conductor layers.