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US 4,058,431 AGranted
Method of etching copper and copper alloys
AssigneeFirma Hans Hollmuller, Maschinenbau
InventorRainer Haas
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Abstract
A method of etching copper and copper alloys by means of an ammoniacal etching solution containing chloride ions and for regenerating this etching solution during this etching process by adding an ammoniacal compound, for example, in the form of ammonium hydroxide or ammonia gas, as well as hydrochloric acid and water to the etching solution in accordance with continuous measurements of the pH-value and the specific gravity of the etching solution.
Claims6
A method of etching copper and copper alloys, comprising the steps of:
- treating copper or a copper alloy with an etching medium consisting of an ammoniacal etching solution containing chloride ions, thereby producing a copper-I compound;
- regenerating the copper-I compound by reacting therewith a chloro compound and by the addition of water to said solution at a rate controlled in dependence upon the rate of formation of said copper-I compounds, the regeneration rate being controlled at least in part by monitoring the specific gravity of the solution;
- and
- supplying to said solution as amount of ammoniacal compound such that the pH value of the latter is maintained at about 8.5 to 10.0.
1 more element
Dependencies are inferred from the claim text.