Learonal, Inc.

William R Brasch

Fred I Nobel

Carlo Favini

Donald W Thomson

Luis H Garay

Anthony J Drago

A substantially cyanide-free plating solution for depositing copper from the monovalent ionic state, which includes monovalent copper ion, a reducing agent capable of reducing divalent copper ions to monovalent copper ions, an alkali material in an amount sufficient to maintain the pH of the solution in the range of about 7 to about 10, and a complexing agent of an imide, such as succinimide, 3-methyl-3-ethyl succinimide, 3-methyl succinimide, 3-ethyl succinimide, 3,3,4,4-tetramethyl succinimide, or 3,3,4-trimethyl succinimide, or a hydantoin, such as dimethyl hydantoin. The substantially cyanide-free plating solutions may also include at least one of a conductivity salt, an additive to promote brightness, or an alloying metal. The reducing agent may be an alkali sulfite, alkali bisulfite, hydroxylamine, or hydrazine. The copper is typically provided in the form of CuCl, CuCl.sub.2, CuSO.sub.4, or Cu.sub.2 O in an amount sufficient to provide a monovalent copper concentration of from about 2 to about 30 grams per liter of solution, and the complexing agent is present in an amount sufficient to provide a molar ratio of copper to complexing agent of from about 1:1 to about 1:5, preferably about 1:4. The alkali material is typically NaOH, KOH, NH.sub.4 OH, or Na.sub.2 CO.sub.3, and the conductivity salt is typically NaCl, KCl, Na.sub.2 SO.sub.4, K.sub.4 P.sub.2 O.sub.7, Na.sub.3 PO.sub.4, C.sub.6 H.sub.5 Na.sub.3 O.sub.7, C.sub.6 H.sub.11 NaO.sub.7, NH.sub.4 Cl, or KNaC.sub.4 H.sub.4 O.sub.6. Useful additives include organic amines or oxyalkyl polyamines, such as triethylene tetramine, tetraethylene pentamine, and polyoxypropyl-triamine. Methods for preparing such a solution for plating copper onto a substrate, and of plating copper onto a substrate with such a solution are also disclosed.

Cyanide-free monovalent copper electroplating solutions

A method for preparing nickel hypophosphite by contacting a nickel anode with a solution of hypophosphite anions and applying a current through the anode to a counter-electrode in contact with the solution to anodically dissolve the nickel of the anode into the hypophosphite solution, thereby forming a nickel hypophosphite solution. A one-compartment electrolysis cell and a three-or-more-compartment electrodialysis cell embodying the method of the invention are described.

Nickel hypophosphite manufacture

Methods for preparing hypophosphorous acid are disclosed comprising contacting an insoluble anode with an aqueous solution of hypophosphite anions and applying a current through the insoluble anode to a cathode in electrical contact with the aqueous solution to generate H+ ions in the aqueous solution thereby forming a hypophosphorous acid solution.

Electrolytic production of hypophosphorous acid

A solution for use in electroplating which comprises at least one monovalent metal such as copper, silver or gold which is complexed by a thiosulfate ion; and a stabilizer of an organic sulfinate compound such as, for example, one having the formula R-SO.sub.2 -X wherein R is an alkyl, heterocyclic or aryl moiety and X is a monovalent cation. The stabilizer is present in an amount sufficient to stabilize the thiosulfate ion when the solution is operated at an acidic pH of less than 7. Also, the solution is substantially free of cyanide.

Cyanide-free plating solutions for monovalent metals

A solution for electroplating gold-copper-silver alloys. The solution comprises gold, copper and silver, each in the form of a cyanide complex. The solution further comprises a divalent sulfur compound capable of brightening and leveling the electroplated deposit of the gold-copper-silver alloy. Optionally, a source of cyanide ions such as a free alkali cyanide, is included in the solution. In addition, additives such as surface active agents, buffers and/or conductivity salts may also be included to impart a particular feature or characteristic to the solution. The invention additionally comprises a process for electroplating up to about 20 microns of a gold-copper-silver alloy upon a substrate utilizing these novel solutions. The alloy is deposited upon a substrate which is immersed in the solution, by electroplating at a current density of between about 1 and 15 ASF, a pH of between about 8-11 at a temperature of between about 100.degree.-170.degree. F. for a time sufficient to obtain the desired thickness. Improved brightness results are obtained with the process of the invention by manipulating the electroplating current.

Electroplated gold-copper-silver alloys

A solution for electroplating gold-copper-zinc alloys. A solution containing excess cyanide and hydroxide ions, gold and copper each in the form of a cyanide complex, and zinc at least partially in the form of a zincate complex. Additives such as conductivity salts, chelating agents, surfactants or wetting agents, brightening agents, and reducing agents may also be present to impart a particular feature or characteristic to the solution. Also, a process for electroplating up to about 20 microns of a gold-copper-zinc alloy upon a substrate using these novel solutions. The alloy is deposited upon a substrate which is immersed in the solution by electroplating at a current density of between about 1 and 15 ASF (0.1 to 1.5 ASDM) at a temperature of about 60.degree. and 120.degree. F. for a sufficient time to obtain the desired thickness. Generally, thicknesses of 5 to 10 microns or more can be obtained without microcracking. Finally, method for increasing the ductility and corrosion resistance of the deposit by simply heating the deposit to about 50.degree. to 200.degree. C. in air for a time of about 2 to 24 hours.

Electroplated gold-copper-zinc alloys

This invention relates to a formaldehyde-free electroless copper plating solution, containing a solution soluble divalent copper compound in a concentration between about 1/2 and 2 g/l; a reducing agent for the copper compound in an amount of between about 1 and 3 g/l; a complexing and chelating agent mixture of between about 5 and 100 ml/l of an alkanol amine having at least one alkyl group with one to three carbon atoms and between about 1 and 10 g/l of an ethylene diamine compound of the formula ##STR1## wherein R is an alkyl moiety having between 1 and 3 carbon atoms and X is --OH or --COOH; the solution preferably having a pH between about 7 and 8.5 and a temperature preferably between about 130.degree. and 150.degree. F., with the complexing and chelating agent mixture being present to provide stability to the solution and to enable the solution to provide a uniform plating rate of copper upon a substrate which is immersed therein.

Formaldehyde-free electroless copper plating solutions

The method for the manufacture of printed circuit boards which have been imaged by means of a polymeric resist which comprises selectively catalyzing those areas not covered by the image by treating the imaged circuit board with a catalyst having a charge higher than the charge on the non-imaged areas and sufficiently lower than the charge on the resist image to cause the catalyst to be repelled therefrom, but sufficiently close to the charge on the non-imaged areas to cause adsorption of the catalysts thereon.

Preparation of printed circuit boards by selective metallization

A copper colloid containing a minor amount of an ionizable palladium compound for use in activating non-conductive materials for subsequent electroplating.

Copper colloid and method of activating insulating surfaces for

Process for printed circuit board manufacture

Method of making copper colloid for activating insulating surfaces

The invention relates to silver plating utilizing low cyanide or non-cyanide silver plating baths by treating the substrate to be plated with a mercaptan and to low cyanide or non-cyanide baths containing a bath soluble mercaptan in a sufficient amount to eliminate or effectively reduce immersion plating of the silver onto the substrate.

Silver plating

The present invention relates to a method of etching copper with a hydrogen peroxide-sulfuric acid etchant containing an acid soluble phosphonic acid in the manufacture of electronic circuits utilizing a masked copper surface and to a method of recovering the copper from the spent etch solution by electrolysis in solid continuous form saleable as electrolytic copper.

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Nesconset, NY, United States of America

William R Brasch