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:
Apr. 22, 2003
Filed:
Nov. 29, 2000
William E. Bernier, Endwell, NY (US);
Donald W. Henderson, Ithaca, NY (US);
James Spalik, Kirkwood, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A single phase flux composition suitable for use with high density arrays, that comprises dicarboxylic acid in an amount sufficient to react with the oxidized surface area in a high-density array, a first organic solvent, and a second organic solvent having a higher evaporation temperature than that of said first organic solvent. Preferred dicarboxylic acids are adipic, pimelic, suberic, azelaic and sebacic acids. Preferably, the composition comprises greater than 6% dicarboxylic acid, more preferably greater that 6% to about 15%, and even more preferably from about 8% to about 10% of the dicarboxylic acid. Preferred amounts of the first organic solvent are in the range of from about 25% to about 75% by weight and preferred amounts of the second organic solvent are from about 10% to about 35% by weight. Preferably, the ratio of the first organic solvent to the second organic solvent is about 3:1. A method for using the inventive composition to solder high density arrays which, for eutectic lead/tin solder, involves heating at extended dwell times and high temperature relative to typical compositions.