A semiconductor device including a semiconductor chip sealed with an encapsulating resin. Columnar electrodes are connected to electrode pads of the semiconductor chip, and extend through the encapsulating resin. The columnar electrodes are made from bonding wires and include enlarged outer ends. Solder balls are arranged on the surface of the encapsulating resin and connected to the outer ends of the columnar electrodes. In another example, pin wires are formed by half-cutting bonding wires, bonding one end of each of the bonding wires, and cutting the bonding wires at the half-cut portions.