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:
Dec. 18, 1990
Filed:
Mar. 20, 1990
Applicant:
Inventors:
Raymond A Letize, West Haven, CT (US);
David D Sullivan, Springfield, MO (US);
William R Thomas, Fair Grove, MO (US);
Thomas D Murry, Springfield, MO (US);
Assignee:
MacDermid, Incorporated, Waterbury, CT (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C23F / ; B44C / ; C03C / ; C03C / ;
U.S. Cl.
CPC ...
156656 ; 134-2 ; 134 27 ; 134 29 ; 156666 ; 156902 ; 252 795 ;
Abstract
After the etching away of copper to selectively expose surface areas of insulating material in a printed circuit process based upon copper foil-clad insulating substrate material, the exposed surface areas of insulating material are contacted with an aqueous alkaline permanganate solution to remove from the areas residual metal species associated therewith so as to improve the electrical resistance afforded by those areas in the printed circuit.