A pad electrode part includes a plurality of pad electrodes transmitting a sensing signal of a sensing cell part to a flexible printed circuit board (FPCB). The pad electrode includes a plurality of widthwise arrangement groups arranged spaced apart in a width direction, and the plurality of widthwise arrangement groups are arranged to be spaced apart in a longitudinal direction as well. A pad electrode of the first widthwise arrangement group and a pad electrode of the second widthwise arrangement group have a same area but different lengths and widths.