| 摘要 |
PROBLEM TO BE SOLVED: To provide a copper-zinc alloy electroplating bath for forming a copper-zinc alloy plating layer having improved corrosion resistance and obtaining the copper-zinc alloy plating layer which has a target composition, is homogeneous and has glossiness over a wide range of electric current density. SOLUTION: The copper-zinc alloy electroplating bath contains copper salt, zinc salt and pyrophosphoric acid ion, wherein a ratio (P/M) of volume molar concentration P (mol/L) of added pyrophosphoric acid ion to total volume molar concentration M (mol/L) of copper ion and zinc ion contained in the bath is in the range of 2.0 to 3.2. The total volume molar concentration M (mol/L) is preferably in the range of 0.03 to 0.50 (mol/L) and pH is preferably in the range of 5 to 10. COPYRIGHT: (C)2010,JPO&INPIT |
