US Patent 7242087 Flexible printed circuit board

A flexible printed circuit board includes a substrate layer composed of insulating material, a protection circuit of a thin-film capacitor element, the protection circuit including a first wiring layer on the substrate layer, a dielectric layer, and a counter electrode layer. At least a portion of each of the first wiring layer and the counter electrode layer serves as a terminal. The front surface of each of the first wiring layer and the counter electrode layer, except the terminal portion, is covered with an insulating coating.