Multi-layer interconnect sutructure for ball grid arrays

A TBGA package for electrically connecting an integrated circuit to a substrate, said package comprising:

• a conductive stiffener;
• a flexible circuit attached to said stiffener, said flexible circuit including at least one dielectric layer and at least one conductor layer;
• an adhesive layer for attaching said flexible circuit to said stiffener;
• a plurality of solder ball bond sites located on said flexible circuit;
• a plurality of solder balls electrically coupled to said plurality of solder ball bond sites;
• a via formed in said flexible circuit and said adhesive layer, said via formed at a location other than said solder ball bond sites and providing a path through which electrical coupling of said stiffener and said flexible circuit may be accomplished;
• and
• a conductive plug within said via, said solder balls and said conductive plug having relative heights such that said solder balls may be attached to said substrate without said conductive plug touching said substrate.

An electronic package for attachment to a substrate, comprising:

• an integrated circuit;
• and
• a ball grid array package, said integrated circuit attached to said ball grid array package, said integrated circuit and said ball grid array package electrically coupled to each other, said ball grid array package comprising,
• a conductive stiffener forming an electrical plane,
• a TAB tape attached to said stiffener,
• a plurality of solder balls electrically coupled to said TAB tape, and
• at least one conductive plug electrically coupling said TAB tape to said conductive stiffener, said conductive plug being horizontally offset from said solder balls;
• wherein said solder balls and said at least one conductive plug have relative heights such that said solder balls may be attached to said substrate without said at least one conductive plug touching said substrate.