Patent ID: 8334594

Claim:
A chip having a metal pillar structure, comprising: a chip body, having an active surface; at least one chip pad, disposed on the active surface; a first passivation layer, disposed on the active surface, and having at least one first opening so as to expose part of the chip pad; an under ball metal layer (UBM), disposed on the chip pad; and at least one metal pillar structure, disposed on the under ball metal layer (UBM), comprising: a metal pillar, disposed on the under ball metal layer (UBM); and a solder, disposed on the metal pillar, wherein the maximum diameter formed by the solder is shorter than or equal to the diameter of the metal pillar, further comprising a second passivation layer, wherein the second passivation layer is disposed on the first passivation layer and has at least one second opening so as to expose part of the chip pad.