Device to renew a bath of copper eletrodeposicap, system for controlling the pH of a bath of eletrodeposicao copper, eletrodialise apparatus and cell eletrodialitica

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).