International Business Machines Corporation

James Spalik

Donald W Henderson

William E Bernier

Issa S Mahmoud

Susan H Downey

Roy Lynn Arldt

Isabelle Paquin

Clement A Okoro

Luis Jesus Matienzo

Irving Memis

Tien Y Wu

Randy William Snyder

Steven F Arndt

Harry J Goldlen

Harry J Golden

A method for protecting tin oxide coated solder surfaces against further oxidation and a method for fluxless solder joining of such surfaces is provided.

Solder protective coating and fluxless joining of flip chip devices on laminates with plated solder

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.

Flux composition and soldering method for high density arrays

An activated no-clean flux composition for soldering includes a dicarboxylic acid, an organic solvent, and acetic acid in the range of about 2% to about 4% by weight.

Composition for increasing activity of a no-clean flux

A new flux composition, as well as corresponding methods for soldering electronic components to printed circuit boards, is disclosed. The new flux composition includes pimelic acid and two organic solvents. Significantly, the new flux composition leaves essentially no ionic residues at the completion of the soldering processes used to mount electronic components onto printed circuit boards.

Flux composition and corresponding soldering method

The present invention provides a novel method for improving the adhesion of polymers, particularly adhesives, to nickel surfaces. The method involves contacting the nickel surface with a hydrogen peroxide solution having a temperature of at least about 40.degree. C. for a time sufficient to form a wettable oxide surface having a water contact angle of less than about 10.degree..

Method for improving the adhesion of polymeric adhesives to nickel

A technique for soldering is provided wherein the solder contains a nominal amount of 4 to 5% tin and the remainder lead. A solder flux is utilized which incorporates a lead compound, such as lead acetate. When the solder and flux is heated, a redox reaction will take place in which the lead ions in the flux will replace the alloyed tin in the solder, thereby reducing the tin content of the solder, whereby the ductility of the solder joint is improved.

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Kirkwood, NY, United States of America

James Spalik