Patent ID: 7667144

Claim:
A circuit board, comprising: a dielectric layer; a circuit layer in contact with the dielectric layer, wherein the circuit layer has at least a pad, and the dielectric layer has at least a through hole exposing the pad; at least a conductive joint column disposed on the pad; and a solder mask layer disposed on the dielectric layer and covering the circuit layer, wherein the solder mask layer is in contact with the conductive joint column, the conductive joint column passes through the solder mask layer, and a height of the conductive joint column is larger than a thickness of the solder mask layer; and at least an electrical connection element encapsulates a top portion of the conductive joint column and separates from the pad by the solder mask layer to form a solder ball having a bottom area in diameter smaller than a height of the solder ball, wherein the circuit layer is embedded into the dielectric layer.