Patent ID: 7462555

Claim:
A method of fabricating a ball grid array substrate, comprising the steps of: (A) providing a substrate which includes a first external layer, a second external layer, and an insulating layer interposed between the first and second external layers; (B) forming a window though the first external layer and the insulating layer; (C) forming a first pattern, which includes first circuit and wire bonding pad patterns, on the first external layer, and forming a second pattern, which includes second circuit and solder ball pad patterns, on the second external layer; (D) forming a solder resist pattern which has openings corresponding to the wire bonding pad patterns and the solder ball pad patterns after solder resists are applied on the first and second external layers; and (E) gold plating the wire bonding pad patterns of the first external layer, the solder ball pad patterns of the second external layer, the window, and the second circuit patterns of the second external layer.