Galvanic bath and process for depositing zinc-based layers
AssigneeEnthone Inc.
InventorAxel Fuhrmann
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Abstract
The preceding invention concerns a galvanic bath as well as a method for depositing a zinc-bearing layer onto a substrate surface. According to the invention, it is provided that the galvanic bath be divided into at least two cell chambers, in which the division occurs by means of a cation-exchange membrane and one cell chamber includes an acidic deposition-electrolyte and the other cell chamber includes a neutral or acidic anolyte. The acidic anolyte here is at least partially removed from the cell chamber containing it and is stripped of the foreign metal ions contained in it by means of a cation-exchange arrangement.
Claims11
A method for galvanic deposition of a zinc-bearing layer onto a substrate surface comprising:
- contacting the substrate surface in a galvanic bath with an acidic deposition-electrolyte comprising zinc ions;
- applying a current between the substrate and at least one anode suitable to deposit the zinc-bearing layer onto the substrate surface, wherein the galvanic bath is divided into at least a first cell comprising the acidic deposition-electrolyte and a second cell comprising a neutral or acidic zinc-bearing anolyte and the at least one anode comprising a zinc anode to be depleted, and wherein the first cell and second cell are separated by a membrane permeable to cations;
- removing at least a portion of the neutral or acidic zinc-bearing anolyte from the second cell;
- and
- directing at least a portion of the neutral or acidic zinc-bearing anolyte removed from the second cell through an arrangement wherein at least a portion of any foreign metal ions are replaced by zinc ions and/or protons.
Dependencies are inferred from the claim text.