Plural pins are arranged on a printed circuit board to form a generally square shape and are electrically connected to terminals of a QFP-IC. In the pins, a pin disposed at a corner portion of the generally square shape is used as a GND terminal, and a pin adjoining the GND terminal is used as a source terminal. A conductive region is provided to extend radially from the corner portion, and is electrically connected to the ground terminal. Further, another conductive region is provided in the generally square shape and is electrically connected to the radial conductive region.