Patent ID: 7420131

Claim:
A wiring substrate comprising: a core substrate including an insulating substrate, a through hole provided through the insulating substrate, a substantially cylindrical through hole conductor formed on an inner circumference of said through hole, and a filling material filling a hollow portion of said through hole conductor; a cover-shaped conductor layer provided on at least one principal face of said core substrate and in a shape containing an end face of said through hole and having conduction to said through hole conductor; a plurality of resin layers provided over said cover-shaped conductor layer; a ball pad conductor provided over said resin layers and having a solder ball to be connected with a connection terminal of an external device; and a connection portion including via conductors buried individually in said resin layers for bringing said cover-shaped conductor layer and said ball pad conductor into conduction, wherein the connection portion comprises a conformal via connected to said cover-shaped conductor layer and one or more filled vias connecting said conformal via to said ball pad, said conformal via having a hole wall, a metallic material arranged along the hole wall, and a resin material filling the remaining portion of the hole, and taking a through direction of said through hole as being a center axis direction, an individual center axes of said via conductor composed of said one or more filled vias and said ball pad conductor are not aligned with the center axis of said through hole.