US Patent 8004851 Multi-layer flexible printed circuit board and manufacturing method thereof

A method for easily making a barrier for preventing overflow of interlayer insulating resin in a cable-fitted multi-layer FPC that uses bumps for connecting the layers, and a barrier having a structure that can easily be made. In a method for manufacturing a multi-layer flexible printed circuit board including a circuit section, a cable section that is connected to the circuit section, the circuit section having a multi-layer structure of insulating resin arranged between multiple layers of metal foil, a barrier, that stops the insulating resin from overflowing, has a two-row configuration and is formed on a metal foil that constitutes an outermost conductive layer in the multi-layer flexible printed circuit board, and the metal foil and the insulating resin are laminated to form the multi-layer flexible printed circuit board.