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, 2001
Filed:
Jan. 18, 2000
Peter T. McGrath, Mission Viejo, CA (US);
Abayomi I. Owei, Rancho Cucamonga, CA (US);
Fry's Metals, Inc., Providence, RI (US);
Abstract
Copper-containing surfaces, such as a copper surface for use in an electrical circuit, are protected by the provision of a bismuth metal coating immersion-plated from a moderately to strongly acidic plating bath. The plating bath preferably contains dissolved bismuth, halide, and a sulfur-containing ligand as a complexing agent that promotes adhesion of the bismuth coating. The bath may be formed from a concentrate system combined with water. The concentrate system may be a two-component system having an acidic first component containing the bismuth, halide, and sulfur-containing ligand, and an alkaline second component containing an additional complexing agent (e.g., EDTA salt). Tarnish resistance of the plated bismuth can be improved by the application of an alkaline composition to neutralize residual acid. Plating thickness can be enhanced by pre-cleaning the surface to be plated with a pre-cleaner containing nitric acid.