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:
Jun. 14, 1994
Filed:
Aug. 10, 1989
Applicant:
Inventors:
Chung-Yao Chao, Hamden, CT (US);
Julius Fister, Hamden, CT (US);
Assignee:
Olin Corporation, New Haven, CT (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C25D / ;
U.S. Cl.
CPC ...
205183 ; 205215 ; 205254 ;
Abstract
The formation of whiskers during tin or tin-lead solder electroplating of a copper base alloy substrate in a methane sulfonate solder plating bath is inhibited by passivating the surface of the substrate prior to electroplating. Preferred passivating solutions include an aqueous solution of sodium dichromate and phosphoric acid, and an aqueous solution of chromic acid and phosphoric acid. Passivation is preferably followed by treatment with a basic solution having a pH of at least 8.