A hinge board having a hinge bending part and a rigid part includes: not
less than two flexible wiring boards including a polyimide sheet layer, a
conductor layer having a circuit formed on both sides or one side of the
polyimide sheet layer, and a coverlay film layer covering the conductor
layer; and a bonding material for bonding the flexible wiring boards. At
least one of the flexible wiring boards is a flexible double-sided wiring
board including the conductor layers on both sides of the polyimide sheet
layer. Moreover, the flexible wiring boards are bonded to each other in
the rigid part by use of the bonding material in such a manner that a
space part is formed between the flexible wiring boards in the hinge
bending part.