Formation of metal images using reducible non-noble metal salts and light sensitive reducing agents
AssigneePhotocircuits Divison of Kollmorgen Corporation
InventorsJoseph Polichette, Edward J. Leech
Life of this patent
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Abstract
Non-conductive real images are formed on substrates by depositing reducible metal salt compositions thereon from an aqueous acidic solution of pH 1.5-5 containing bromide ions and exposing the coated substrates to radiant energy to reduce the metal salt to metallic nuclei and to produce a real image of metal, which is intensified and built up by electroless metal deposition. The metal salt composition can either be selectively deposited and then exposed, or uniformly deposited and then selectively exposed, to produce the real image.
Claims59
In a process for selectively metallizing insulating substrates with real images, the steps which comprise depositing on said substrate a layer of a radiation-sensitive composition by treating the substrate with a solution having a pH between about 1.5 and 4.0 as well as a minor content by weight of at least one halide ion of the group consisting of chloride, bromide and iodine ions and comprising a reducible salt of a non-noble metal with the cations of said metal present in a larger proportion of equivalents than said halide ions, a radiation-sensitive reducing agent for said salt, and a secondary reducer in an aqueous medium, and exposing said layer to radiant energy to reduce said metal salt to metallic nuclei thereof and wherein at least one of said treating and exposing steps is restricted to a selected pattern on said substrate to produce a non-conducting real image of said metallic nuclei in said selected pattern and capable of directly catalyzing the deposition thereon of metal from an electroless metal bath.
In a process for selectively metallizing insulating substrates with real images, the steps which comprise depositing on said substrate a layer of a radiation-sensitive composition by treating the substrate with a solution having a pH between about 1.5 and 4.0 as well as a minor content by weight of at least one halide ion of the group consisting of chloride, bromide and iodine ions and comprising a reducible salt of a non-noble metal with the cations of said metal present in a larger proportion of equivalents than said halide ions, a radiation-sensitive reducing agent for said salt, and a secondary reducer in an aqueous medium, and selectively exposing said layer to light to reduce said metal salt to metallic nuclei thereof to produce a non-conducting real image of said metallic nuclei in said selected pattern and capable of directly catalyzing the deposition thereon of metal from an electroless metal bath.
In a process for selectively metallizing insulating substrates with real images, the steps which comprise depositing on said substrate a layer of a radiation-sensitive composition by treating the substrate with a solution having a pH between about 1.5 and 4.0 as well as a minor content by weight of at least one halide ion of the group consisting of chloride, bromide and iodine ions and comprising a reducible salt of a non-noble metal with the cations of said metal present in a larger proportion of equivalents than said halide ions, a radiation-sensitive reducing agent for said salt, and a secondary reducer in an aqueous medium, and selectively exposing said layer to ultraviolet radiation to reduce said metal salt to metallic nuclei thereof to produce a non-conducting real image of said metallic nuclei in said selected pattern and capable of directly catalyzing the deposition thereon of metal from an electroless metal bath.
An article which comprises an insulating substrate, an aperture in said substrate, at least a selected area of the wall surface of said aperture being coated with a radiation-sensitive composition having a minor content of at least one halogen of the group consisting of chlorine, bromine and iodine and comprising a reducible salt of a non-noble metal with the content of said metal amounting to a larger proportion of equivalents than said halogen, a radiation-sensitive reducing agent for said salt, a secondary reducer and an acid.
Dependencies are inferred from the claim text.