Electrochemicals, Inc.

Beth Ann LaFayette

Frank Polakovic

Michael Val Carano

Roger Bernards

Charles Edwin Thorn

Thao Pham

William Yang

A corrosive composition, such as an alkaline aqueous carbon dispersion, a cleaner, a cleaner conditioner, or a conditioner, comprises a corrosion inhibitor, e.g., benzotriazole. The corrosion inhibitor is present in an amount effective to reduce or stop the dissolution of metal from a metallic surface, such as a printed circuit board, in contact with the composition. A method to reduce or stop the dissolution of metal from a metallic surface in contact with a corrosive composition, and a method to stabilize or recover a corrosive composition containing metal contaminants by adding an effective amount of a corrosion inhibitor to the corrosive composition.

Additives to stop copper attack by alkaline etching agents such as ammonia and monoethanol amine (MEA)

A desmear process for removing resin smeared on an interior wall of a through hole drilled in a resinous substrate, especially resinous substrates made from epoxy, polyimide, cyanate ester resins or bis-maleimide triazine epoxy resins. The process involves contacting the resin smear with a mixture of gamma-butyrolactone and water to soften the resin smear, followed by treatment with an alkaline permanganate solution to remove the softened resin, and treatment with an aqueous acidic neutralizer to neutralize and remove the permanganate residues. The gamma-butyrolactone is effective as a single solvent for softening and swelling resin smears from substrates made from epoxy, polyimide, cyanate ester resins, bis-maleimide triazine epoxy resins, and polyimide resins.

Permanganate desmear process for printed wiring boards

An improved desmear process for removing resin smeared on an interior wall of a through hole drilled in a resinous substrate, especially resinous substrates made from epoxy, polyimide, cyanate ester resins and bis-maleimide triazine epoxy resins. The process involves contacting the resin smear with a solvent solution to soften the resin smear, followed by treatment with an alkaline permanganate solution to remove the softened resin, and treatment with a neutralizer to neutralize and remove the permanganate residues. The solvent solution comprises a mixture of at least two solvent components, with at least one solvent component being selected from the group consisting of gamma-butyrolactone, ethyl-3-ethoxypropionate, N-ethyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-(2-hydroxyethyl)-2-pyrrolidone, and N-octyl-2-pyrrolidone. The solvent solution is selective for the softening and removal of epoxy, polyimide, cyanate ester resins and bis-maleimide triazine epoxy resins.

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Minneapolis, MN, United States of America

Beth Ann LaFayette