| 摘要 |
PURPOSE:To protect a bonding gold plating solution against contamination caused by a nickel plating solution by a method wherein a strike gold plating process is provided as a pre-treatment process for a bonding gold plating process. CONSTITUTION:A circuit substrate subjected to a rinsing process after a nickel plating process is dipped into an Au plating tank to form a gold plating layer 0.04mum or so in thickness on a nickel plating layer on a wiring pattern provided onto the circuit substrate. By this setup, a strike Au plating solution whose type is the same as that of a bonding Au plating solution is attached to the circuit substrate at a rate of 99.99% by area after the substrate is through an Au plating process and the amount of an Ni plating solution attached to the substrate is almost zero when the substrate is dipped into a bonding Au plating tank, so that the bonding Au plating tank is protected against contamination caused by an Ni plating solution and a stable bonding Au plating layer can be formed on the wiring pattern provided onto the circuit substrate. |
