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. 07, 2002
Filed:
Apr. 10, 2000
Gerald L. Ballard, Wake Forest, NC (US);
Robert D. Edwards, Endicott, NY (US);
John G. Gaudiello, Poughkeepsie, NY (US);
Voya R. Markovich, Endwell, NY (US);
International Business Machines Corp., Armonk, NY (US);
Abstract
Gold is deposited on a copper base defining electrical circuit features disposed on a substrate containing a palladium seeder, by initially treating the substrate with an alkaline cleaner, followed by treating the substrate with sodium persulfate, and subsequently treating the substrate with a diluted sulfuric acid solution. The substrate is rinsed between each one of the treatments, and after the final rinse following treatment with diluted sulfuric acid, the substrate is immersed in a gold deposition solution whereby gold is deposited on the exposed surfaces of the copper circuit features on a substrate. The process embodying the present invention provides a method for depositing gold on high density copper conductor lines or pads, even in areas of the surface in which the conductors are spaced apart 2.0 mil or less, without cleaning or removing the palladium seed from the surface.