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:
May. 02, 1995
Filed:
Jul. 13, 1993
George S Bokisa, Sr, North Olmsted, OH (US);
Gary W Loar, Parma, OH (US);
Americus C Vitale, West Chester, PA (US);
McGean-Rohco, Inc., Cleveland, OH (US);
Abstract
A novel, environmentally innocuous, post-etch, pre-soldering cleaner and cleaning process is disclosed for removing contaminants from plated surfaces of printed circuit boards manufactured by the pattern plating method. The post-etch, cleaning process of this invention, for removing contaminants from plated surfaces of an etched printed circuit, comprises treating the plated surfaces with a cleaning solution which comprises an aqueous solution of (i) an imidazole-2-thione compound and (ii) an acid. The imidazole-2-thione compound has the formula: ##STR1## wherein A and B are the same or different --R--Y groups, wherein R is a linear, branched or cyclic alkenyl group containing 1 to 12 carbon atoms and Y is a hydrogen, halogen, cyano, vinyl, phenyl or ether moiety. Of this class of compounds, 1-methyl-3-propylimidazole-2-thione is preferred. The novel aqueous cleaners of this invention are effective replacements for conventional cleaners containing the toxic material thiourea and are superior to cleaners free of thiourea.