Abstract: 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.

Abstract: 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.

Abstract: 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.