An interconnection structure is disposed between a first conductive layer and a second conductive layer substantially parallel to each other. The conductive layer includes a signal trace. The interconnection structure includes a conductor pillar and a shielding wall pillar. The conductor pillar goes through between the two conductive layers and is electrically connected to the signal trace of the first conductive layer. The shielding wall pillar is also disposed between the two conductive layers and located at a portion of an external region surrounding the conductor pillar and electrically coupled to the conductor pillar. The conductor pillar and the shielding wall pillar are disposed in pair or in group. The shielding wall pillar with a shape different from that of the conductor pillar would make the conductor pillar serve as a connection with a designed impedance and the capability of controlling impedance based on the special shape design thereof.