| 摘要 |
PURPOSE:To allow electroless Ni or Co plating work to stably continue over a long term by measuring the concn. and specific gravity of a plating both to supply consumed chemicals and partially renew the bath. CONSTITUTION:In electroless Ni, Co or Ni-Co alloy plating, part of plating bath 2 in plating cell 1 is circularly passed through circulation pipe 6 provided with concn. detector 3 and specific gravity detector 4. The concn. of metal ions of Ni or the like is measured with detector 3, and in accordance with signal A given magnet valve 19 of other tank 16 filled with an aqueous metal salt soln., a reducing agent, a pH adjusting agent, etc. is opened to supply wanting liq. chemicals. When bath 2 is aged and has higher specific gravity, the gravity is detected with detector 4, and signal B is sent to pump 22 to discharge part of bath 2 and supply a fresh plating bath from tank 24. Thus, the time for preparing a plating bath again can be elongated considerably. |
