International Business Machines Corporation

Randy William Snyder

Victor Y Lee

Francis Charles Burns

William Weathers Fleming

Gareth Geoffrey Hougham

Claudius Feger

Peter Slota, Jr

John J Ritsko

Steven E Molis

James Spalik

Walter P Pawlowski

John J Glenning

Steven L Bard

The present invention provides an ablatively photodecomposable polymer having a photoabsorber bound to the polymer (the 'ablatively photodecomposable polymer') which does not phase separate, nor does it crystallize. The ablatively photodecomposable polymer provides even ablation, high resolution and in preferred embodiments, can withstand potassium permanganate etchant and ferric chloride etchant. The ablatively photodecomposable polymer is strippable, although it can remain on the substrate if desired. The ablatively photodecomposable polymer comprises a polymer to which a photoabsorber is bound, either covalently or ionically. The present invention is also directed to a process for forming a metal pattern on a substrate employing the ablatively photodecomposable polymer.

Ablatively photodecomposable compositions

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.

Flux composition and method of decreasing tin content in lead/tin solder

Polyimide is etched by contacting the polyimide with an aqueous solution of a metal hydroxide followed by contact with an acid followed by contact with an aqueous solution of a metal hydroxide. Etching of chemically cured polyimide can be enhanced by employing a presoaking in hot water. Also, partially etched chemically cured polyimide is removed with a concentrated acid solution. In preparing a metal coated polyimide structure for subsequent gold plating, two flash etching steps with the polyimide etch between are employed after developing the photoresist.

Wet etching of thermally or chemically cured polyimide

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Vestal, NY, United States of America

Randy William Snyder