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:
Feb. 25, 2003
Filed:
Aug. 26, 1999
Karl F. Wengenroth, Stratford, CT (US);
Enthone Inc., West Haven, CT (US);
Abstract
A method is provided for the selective deposition of an organic solderability preservative (OSP) coating on copper surfaces of articles such as electronic components, e.g., printed wiring boards, to serve as a protective coating and preserve the solderability of the copper surface while substantially excluding gold surfaces from attracting the same OSP coating which coating causes cosmetic defects in the form of staining and may reduce the conductivity of the gold contact surface. The method improves the conventional OSP process and utilizes a pre-treatment of the copper surface before applying the OSP coating comprising treating the cleaned and preferably micro-etched copper with an aqueous solution of benzimidazole or derivative thereof to form a precoat on the copper surface. After the pre-treatment step, the precoated copper surface is conventionally treated with a suitable OSP solution such as an aqueous solution of a substituted benzimidazole compound, preferably at the 2-position.