Patent ID: 7838967

Claim:
A semiconductor chip primarily comprising: a semiconductor substrate having a first surface, a corresponding second surface, a plurality of through holes penetrating from the first surface to the second surface; a plurality of first bonding pads disposed on the first surface; a plurality of second bonding pads disposed on the second surface and aligned with the first bonding pads, wherein the through holes further penetrate through the first bonding pads and the second bonding pads; a plurality of first extruded rings extrusively disposed on the first bonding pads in a manner that each first bonding pad has a first contact surface exposed on the first surface and the first contact surfaces are located between the corresponding first extruded rings and the corresponding through holes; and a plurality of second extruded rings extrusively disposed on the second bonding pads in a manner that each second bonding pad has a second contact surface exposed on the second surface and the second contact surfaces are located outside and adjacent to the corresponding second extruded rings to encircle the corresponding second extruded rings; wherein the second extruded rings have a dimension to fit into the first extruded rings.