Patent attributes
A flexible multilayer wiring board manufactured by laminating a metal foil via an insulating layer to cover the first layer circuit wiring formed on a conductive substrate, and a resist layer is formed to cover the second layer circuit wiring formed by pattern-etching the metal foil. Using the conductive substrate as a power feeding layer, a conductive material is filled, by electrolytic plating, into interlayer via holes each formed applying a laser beam to the resist layer to establish interlayer connection between the first and second layer circuit wirings. Using the conductive substrate as a power feeding layer, a conductive material is filled, by electrolytic plating, into hole portions of an insulating layer formed to cover the second layer circuit wiring to form external connection terminals. Then, the conductive substrate is removed entirely or partly to expose the first layer circuit wiring.
