Display device, flexible wiring board, method of manufacturing the display device, and electronic device

An electronic device comprising:

• a glass substrate;
• a plurality of pad portions arranged along a first direction on the glass substrate;
• and
• a flexible printed circuit mounted on the plurality of pad portions, wherein
• the flexible printed circuit comprises a base member comprising a first surface and a second surface on an opposite side to the first surface, wiring lines located on the first surface, and a protective layer which covers the wiring lines,
• the base member comprises a first edge, a second edge, and a groove portion formed on the second surface,
• the groove portion is located between the first edge and the second edge along the first direction,
• the both ends of the groove portion along the first direction are located on inner sides with respect to the first edge and the second edge, respectively,
• the groove portion is not penetrating the base member,
• a first of both ends of the groove portion is located on a side of the first edge and a second end is located on a side of the second edge,
• a thickness of the base member between the first edge and the first end is greater than a thickness of the base member in the groove portion, and
• a thickness of the base member between the second edge and the second end is greater than a thickness of the base member in the groove portion, wherein a distance between the first edge and the first end along the first direction and a distance between the second edge and the second end along the first direction are each 0.2 mm or greater but 0.5 mm or less.