Flexible printed board and flexible printed board connection structure

A flexible printed board comprising:

• an insulating base material;
• a plurality of first wiring lines disposed on a front surface side of the insulating base material, the plurality of first wiring lines being arranged in a length direction of the insulating base material and the plurality of first wiring lines extending in a width direction of the insulating base material;
• a plurality of first terminals disposed on the front surface side, each of the plurality of first terminals provided on an external connection side, of a respective one of the plurality of first wiring lines;
• a plurality of second wiring lines disposed on a rear surface side of the insulating base material, the plurality of second wiring lines being arranged in the length direction of the insulating base material and the plurality of second wiring lines extending in the width direction of the insulating base material;
• a plurality of second terminals disposed on the rear surface side, each of the plurality of second terminals provided on an external connection side, of a respective one of the plurality of second wiring lines;
• and
• a connection member including a conductive adhesive layer and a plurality of connection terminals electrically connected to the plurality of first terminals and the plurality of second terminals via the conductive adhesive layer, wherein the insulating base material includes a restraining space at each end of the insulating base material in the width direction of the insulating base material, which is outside of a first outermost terminal among the plurality of first terminals in the length direction and outside of a second outermost terminal among the plurality of second terminals length direction, the restraining space configured to restrain surface flashover of electrical discharge occurring between the first outermost terminal via a first outflow portion of the conductive adhesive layer between the connection member and the first outermost terminal and the second outermost terminal via a second outflow portion of the conductive adhesive layer between the connection member and the second outermost terminal around a side surface of an edge of the insulating base material.