Patent ID: 8922002

Claim:
A semiconductor workpiece, comprising: a substrate; a plurality of dies formed at the substrate, the individual dies including an integrated circuit and a plurality of terminals operably coupled to the integrated circuit; a plurality of first conductive balls electrically coupled to corresponding terminals, the individual first conductive balls having a proximal portion proximate to the substrate and a generally flat distal portion opposite the proximal portion, wherein the generally flat distal portion is formed without removing material from the conductive balls; a protective layer having a first surface facing the substrate and a second surface opposite the first surface, wherein the distal portion of the individual first conductive balls projects from the second surface of the protective layer, wherein a diameter of the flat distal portions of the individual first conductive balls is smaller than a corresponding aperture in the second surface of the protective layer; and a plurality of second conductive balls attached to corresponding first conductive balls, wherein the first conductive balls and the second conductive balls form a stacked structure.