Patent ID: 7973414

Claim:
A semiconductor package through-electrode formed through a semiconductor chip between a first surface and a second surface located at the opposite sides of the semiconductor chip, the semiconductor package through-electrode comprising: a first electrode having a recessed portion formed therein to pass through the semiconductor chip; and a second electrode disposed within the recessed portion of the first electrode, wherein the first and second electrodes each having a semi-circular extension portion at the first surface of the semiconductor chip, wherein sides of the second extension portion are curved so that an area of the second electrode at the first surface is greater than an area of the second electrode at the second surface and wherein the sides of the first extension portion are curved so that a perimeter of the first extension portion at the first surface is greater than a perimeter of the first electrode at the second surface, and wherein the second electrode disposed within the first electrode is exposed at the first surface of the semiconductor chip, and wherein the second surface of the semiconductor chip is closed by the first electrode, and wherein the first electrode comprises a first metal having a first melting point, and the second electrode comprises a second metal having a second melting point lower than the first melting point.