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. 17, 1990
Filed:
Dec. 19, 1988
David J Lapham, Widnes, GB;
Geoffrey Hitchmough, Runcorn, GB;
Micro-Image Technology Limited, London, GB;
Abstract
A photoresist stripping solution is prepared by adding hydrogen peroxide to concentrated sulphuric acid under controlled temperature conditions, preferably at below 20.degree. C. The concentration of the sulphuric acid in the solution is preferably maintained at at least 80% wt to maximize the concentration of the active stripping species permonosulphuric acid. Stripping solutions having extended storage life have a content of soluble tim compound preferably sodium stannate and preferalby also a phosphonate sequestrant which shows a synergism with the tin compound. Such extended life solutions also preferably have a low content of transition metals and of particles. The stripping solution may be utilized at ambient temperature.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile