The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 03, 1979
Filed:
Sep. 14, 1977
Warren A Nelson, Hohokus, NJ (US);
Philip A. Hunt Chemical Corp., Palisades Park, NJ (US);
Abstract
An improvement in an etching process in which the etched product, the surface of which is covered with a film of aqueous etching liquid containing ions of the material etched, is rinsed with an aqueous liquid and the resulting liquid, now containing said ions in dilute concentration, is passed through an ion exchanger to selectively remove the ions from the rinse liquid which thereupon can be reused or discharged, without ecological damage, from the ion exchanger. The ion exchanger when laden with such ions is regenerated by passage therethrough of at least a portion of an etcher make-up aqueous replenishing solution which contains a zero or low concentration of said ions. The resulting replenishing solution portion, now containing a small concentration of these ions, is passed to the etcher, e.g., to the etcher sump.