The electrodialysis apparatus for chemical maintenance of non-electrolytic kobberpletteringsbade

摘要

Apparatus for preventing depletion of an electroless copper plating bath (66) comprises an electrolytic cell (26) divided by permselective membranes (38,40) into a catholyte compartment (28), an anolyte compartment (32) and between them an electroless copper solution compartment (36). A catholyte such as aqueous sodium hydroxide is circulated to and from the catholyte compartment from a source (62) by a pump (54). An anolyte such as aqueous sulphuric acid is circulated to and from the anolyte compartment (32) from a source (60) by a pump (58) and the electroless copper solution is circulated from the plating bath (66) to the copper solution compartment (36) of the cell and back, by a pump (68).