摘要 |
A control apparatus for automatically controlling at least the concentration of copper-ions, hydroxyl-ions and formaldehyde-ions in an electroless copper plating bath and independently analyzing, displaying and replenishing the concentration of each such ions whereby a sample for each of the ions is discontinuously removed from the plating bath and diluted with a specific amount of water and, independently of one another, the copper-ion concentration is colorimetrically analyzed, displayed and replenished as needed, the hydroxyl-ion concentration is potentiometrically analyzed, displayed and replenished as needed and the formaldehyde-ion concentration is amperometrically analyzed, displayed and replenished as needed. |