Patent ID: 7053312

Claim:
A flexible wiring board, comprising: a metal foil not patterned; a resin film having flexibility disposed on a top surface of said metal foil; and metal bumps of which bottoms are connected to the top surface of said metal foil, wherein no metal bumps are disposed on a bottom surface of said metal foil, the bottom surface being flat, and the tops of said metal bumps are projected from said resin film, wherein said resin film includes a thermosetting resin film and a thermoplastic resin film developing adhesiveness upon heating, said thermosetting resin film contacts said metal foil, and said thermoplastic resin film is disposed on the surface of said thermosetting resin film, said thermoplastic resin film is exposed, and wherein said thermosetting resin film is disposed in the vicinities of said metal bumps, sides of said metal bumps are surrounded by said thermosetting resin film, and said thermosetting resin film is exposed on the surface of the vicinities of said metal bumps.