| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a circuit board including circuits having excellent corrosion resistance. <P>SOLUTION: In the circuit board, a plated underlayer 4 of a circuit pattern is formed by radiating the laser L, along a contour of a circuit 3, to a metal thin film 2 covering the front surface of an insulting substrate 1 to remove the metal thin film 2 in the contour of the circuit 3 and the circuit 3 is formed by sequentially executing the metal plating to the front surface of the plated underlayer 4 in the sequence of a Cu plated layer 5, a Ni plated layer 6, and a Au plated layer 7 from the plated underlayer 4 side. 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. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
