Patent ID: 8822828

Claim:
A multi-layer printed circuit board comprising: a core structure comprising a first resin layer forming a single layer comprising a thermosetting resin, a second resin layer forming a single layer comprising a thermosetting resin formed on and in contact with the first resin layer, and a plurality of conductor circuits sandwiched by the first and second resin layers such that the conductor circuits are formed into the second resin layer, 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; a second conductor layer comprising a plurality of conductor circuits formed on the second surface of the core structure; a first interlayer resin insulating layer formed on the first surface of the core structure and the first conductor layer; and a second interlayer resin insulating layer formed on the second surface of the core structure and the second conductor layer, wherein the core structure includes a plurality of first via holes formed in the first resin layer and a plurality of second via holes formed in the second resin layer, the first via holes and the second via holes comprise a plating material filling up to the respective top of a plurality of openings formed in the first and second resin layers, respectively, and are positioned such that the first via holes and the second via holes form direct contact with at least one of the conductor circuits in the core structure and form a plurality of through hole structures configured to electrically connect respective ones of the conductor circuits of the first and the second conductor layers, and the plurality of through hole structures includes a first through hole structure comprising one of the first via holes and one of the second via holes aligned in a vertical direction and a second through hole structure comprising one of the first via holes and one of the second via holes obliquely positioned each other with respect to the at least one of the conductor circuits in the core structure.