| abstract |
A multi-layer printed circuit board including a core structure comprising resin layers and conductor circuits 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 including conductor circuits formed on the first surface of the core structure, and a second conductor layer including conductor circuits formed on the second surface of the core structure. The core structure includes a first via hole and a second via hole, and the first via hole and the second via hole include a metal filling up to the respective top of openings formed in the resin layers, respectively, sandwich one or more conductor circuits 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. |