CIRCUIT BOARD AND METHOD FOR MANUFACTURING THE SAME

摘要

A circuit board is provided with an insulating substrate (1) and a circuit (3) formed on the insulating substrate (1). The circuit is provided with a plated base layer (4) whereupon a pattern is formed by irradiating a metal thin film (2) applied on a surface of the insulating substrate (1) with a laser beam (L) along the profile of the circuit (3) and partially removing the metal thin film (2) from the profile of the circuit (3). The circuit is also provided with a Cu-plated layer (5), an Ni-plated layer (6) and an Au-plated layer (7), which are formed by metal plating, on a surface of the plated base layer (4) in this order from the side of the plated base layer. Between the Ni-plated layer (6) and the Au-plated layer (7), a first intermediate plated layer (8) having a less noble metal than Au with respect to reference electrode potential is formed in contact with the Au-plated layer, and a second intermediate plated layer (9) having a more noble metal than the metal in the first intermediate plated layer with respect to the reference electrode potential is formed in contact with the first intermediate plated layer (8).