Western Electric Company, Inc.

William M Beckenbaugh

Kim L Morton

Patricia J Goldman

Donald Dinella

Theodore D Polakowski, Jr

Michael Anthony De Angelo

Ted Dennis Polakowski, Jr

In an improved method for depositing a metal on a substrate of the type in which a dielectric coated substrate is coated with a sensitizing solution containing a reductible metal salt, a primary reducing agent comprising 2,7 anthraquinone disulfonic acid and a secondary reducing agent, the substrate is exposed to ultraviolet light in an atmosphere having a temperature of at least 117.degree. F. (42.degree. C.) and a mass of water vapor of at least 3.8 mg of water per liter of dry air for at least 15 seconds. In an embodiment of the method the substrate is aerated in a moisture controlled atmosphere at room temperature for at least 30 minutes prior to exposing the substrate to ultraviolet light.

Methods of depositing metallic copper on substrates

The method of depositing a metal on a surface especially suitable for the manufacture of printed circuit boards includes coating the surface with a sensitizing solution comprising an inaqueous solvent solution, a reducible salt of a non-noble metal, a salt of 2,7 anthraquinone disulfonic acid and a polyol type secondary reducing agent such as sorbitol. The coated surface is then dried and the dried surface may be stored for extended periods of time before further processing which consists of imaging the sensitized surface with ultraviolet light and electrolessly plating a metal over the imaged surface.

Method for depositing a metal on a surface

A method of selectively depositing a metal on a surface of a substrate is disclosed. A suitable substrate is selected and a surface is treated with a reducing agent selected from the group consisting of (a) hydrazine, (b) a substituted hydrazine having the structural formula ##STR1## where R.sub.1 is an organic radical selected from the group consisting of alkyl, cycloalkyl, aryl, alkaryl, aralkyl, alkoxy, aryloxy and heterocyclic radicals and R.sub.2, R.sub.3 and R.sub.4 are the hydrogen radical or are the same as R.sub.1, and (c) a mixture of the foregoing. The reducing agent treated surface is selectively exposed to a source of ultraviolet radiation to render a selected area thereof incapable of reducing an activating metal species and to delineate an unexposed area so capable. The selectively radiation-exposed surface is treated with an activating metal species to activate the delineated, unexposed area.

Method of selectively depositing a metal on a surface of a substrate

A method of depositing a stress-free electroless copper deposit is disclosed. The method comprises contacting a catalyzed surface with a solution comprising a source of cupric ions; a reducing agent for the cupric ions; a complexing agent for the solution selected from (a) ethylenediaminetetraacetic acid, (b) a salt of (a), (c) a modified ethylenediamine acetic acid, (d) a salt of (c), and (e) a mixture of at least two of the foregoing complexing agents; a stabilizer for the solution comprising a mercury compound; and an accelerator for the solution comprising a water-soluble compound containing a cyanide radical (CN.sup.-) complexed with a metal selected from Group VIII of the Periodic Table of the Elements.

Method of depositing a stress-free electroless copper deposit

A method of depositing a metal on a surface is disclosed. The method comprises coating the surface with a sensitizing solution comprising at least a reducible salt of a non-noble metal. The coated surface is selectively treated to reduce the metal salt to metallic nuclei to form a catalytic pattern thereon capable of directly catalyzing the deposition of a metal on the nuclei from an electroless metal deposition solution. The selectively treated surface is then exposed to a stripping solution comprising an organic acid selected from (a) a carboxylic acid having a structural formula of ##STR1## where R is a member selected from the hydrogen radical, H, and an alkyl group having 1 to 3 carbon atoms, (b) citric acid and (c) a mixture of any of the foregoing acids, to essentially remove portions of the coated surface which have not been selectively treated.

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East Amwell Township, NJ, United States of America

William M Beckenbaugh