Second individual electrodes are formed and arranged in zigzag in two rows on one surface of a flexible sheet, and wirings connected to the second individual electrodes are arranged to pass between adjacent second individual electrodes of the other row. Formed on the other surface of the flexible sheet are electrode connection sections to be connected to the second individual electrodes through through-holes going through the flexible sheet. The electrode connection section has an area larger than the second individual electrode and is connected to an external electrode through solder.