A base insulating layer of an FPC board includes a rectangular first insulating portion and a second insulating portion that outwardly extends from one side of the first insulating portion. A conductor layer is formed on one surface of the base insulating layer. The conductor layer includes a pair of rectangular collector portions and a pair of extraction conductor portions that extend in a long-sized shape from the collector portions. One collector portion is formed in a first region of the first insulating portion of the base insulating layer, and the other collector portion is formed in a second region of the first insulating portion. One extraction conductor portion extends from the one collector portion to the second insulating portion, and the other extraction conductor portion extends from the other collector portion to the second insulating portion.