| 摘要 |
PROBLEM TO BE SOLVED: To eliminate damages to a via by nucleating a plating nucleus on the via exposed with a surface of a ceramic board, then forming a metallic film on the via by an electroless plating method, and then roughing the surface of the ceramic board. SOLUTION: A plating nucleus is nucleated on a via, exposed with a surface of a baked ceramic board. Nucleating liquid used for this contains palladium, so that its pH is preferably 4 to 9. Then, after a metallic film is formed on the via by an electrolessly plating method, it is heat-treated at 300 to 450. Thereafter, the surface of the board formed with the metallic film is roughed by using hydrofluoric acid. Accordingly, since it is roughened after the film has been formed, elution of the glass component in the via is prevented so that no air gap is generated in the via. |
