| 摘要 |
A Sn alloy plating apparatus of the present invention comprises: an anion exchanging membrane (54) partitioning the inside of a plating bath (16) into a cathode chamber (12) which keeps a Sn alloy plating solution (Q) and soaks and arranges a substrate (W) in the Sn alloy plating solution, and an anode chamber (14) which keeps anolyte (E) containing Sn ions, bivalent Sn ions, and acid forming a complex and soaks and arranges an Sn Anode (32) in the anolyte; and an electrolyte supply line (24) for supplying electrolyte containing the acid in the anode chamber. The electrolyte supply line (24) supplies the electrolyte into the anode chamber and supplies the increased anolyte in the anode chamber by the supply of the electrolyte to the Sn alloy plating solution in order to keep the Sn ion density of the anolyte in the anode chamber above a predetermined value and to prevent the density of the acid from dropping below the permissible level. |
