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AssigneeElectrochem International, Inc.
InventorDavid W. Grenda
Estimating the term…
A process is provided for regenerating a spent electroless copper plating bath which contains alkali metal salts resulting from the reduction of a water soluble copper salt under copper plating and reducing conditions. The regeneration is effected by means of the electrodialytic transfer of at least a portion of the anions in the spent plating bath through an anionic permselective membrane into the anode compartment of an electrodialytic cell. In the preferred embodiment, hydroxyl ions from the cathode compartment of the electrodialytic cell are concurrently transferred through a second anionic permselective membrane to replace the transferred anions, the replacement taking place in a compartment of the electrodialytic cell located between the two anionic permselective membranes.
In a process for electrodialytically regenerating a spent electroless copper plating bath resulting from the reduction of a water soluble cupric salt in an alkaline solution under copper plating and reducing conditions, said spent solution containing alkali metal salts as reaction products,
In a process for electrodialytically regenerating a spent electroless copper plating bath resulting from the reaction of a water soluble cupric salt with formaldehyde and an alkali metal hydroxide in the presence of an agent to prevent precipitation of copper hydroxide under copper plating and reducing conditions, said spent solution containing alkali metal salts as reaction products,
In a process for electrodialytically regenerating an electroless copper plating bath wherein a cupric salt is reacted in an aqueous solution containing the sodium salt of ethylenediaminetetraacetate with an alkali metal hydroxide and formaldehyde under copper plating and reducing conditions in an electroless plating bath to yield a spent solution containing alkali metal formate and alkali metal sulfate as reaction products,
Dependencies are inferred from the claim text.