The present invention is an improved hermetic package for implantation in the human body. The implantable device comprises an electrically non-conductive substrate; a plurality of electrically conductive vias through said electrically non-conductive substrate; a flip-chip circuit attached to said electrically non-conductive substrate using conductive bumps and electrically connected to a first subset of said plurality of electrically conductive vias, wherein said flip-chip circuit contains one or more stacks or a folded stack; a wire bonded circuit attached to said electrically non-conductive substrate and electrically connected to a second subset of said electrically conductive vias; and a cover bonded to said electrically non-conductive substrate, said cover, said electrically non-conductive substrate and said electrically conductive vias forming a hermetic package.