A palladium deposition bath and its use for highly controlled electroless palladium deposition on nanoparticulate structures

摘要

Composition of a plating bath for an electroless palladium plating comprises: an aqueous palladium salt; at least one reducing agent comprising e.g. reducing phosphorus compounds, reducing nitrogen compounds, reducing boron compounds; at least one complexing agent comprising polyaminocarboxylic acids, heteroaromatic compounds, pyridines, beta -diketones, amines, ammonia, chelatamine, ethylenediamine, carboxylic acids, nitrite, acetylacetone; and additional adsorbate-former comprising e.g. metal salts, transition metal complexes, and adsorbtive water-soluble polymers and beta -diketones. Composition of a plating bath for an electroless palladium plating comprises: an aqueous palladium salt; at least one reducing agent comprising reducing phosphorus compounds, reducing nitrogen compounds, reducing boron compounds, reducing amine stabilized borane, reducing organic compounds, hypophosphites, hydrazine, boron hydride, and formaldehyde; at least one complexing agent comprising polyaminocarboxylic acids, heteroaromatic compounds, pyridines, beta -diketones, amines, ammonia, chelatamine, ethylenediamine, carboxylic acids, nitrite, acetylacetone; and additional adsorbate-former comprising metal salts, transition metal complexes, oxoanions, pyridine, heteroaromatic compounds, xanthates, and adsorbtive water-soluble polymers and beta -diketones. Independent claims are also included for: (1) preparing a plating bath for the electroless palladium plating comprising producing a first solution containing an aqueous palladium salt solution, at least one complexing agent and at least one adsorbate-former and a second solution containing reducing agent diluted in water, and mixing these solutions in a volume ratio of 1+- 0.5 parts first solution to 1+- 0.5 parts second solution; and (2) use of the plating bath for the electroless palladium plating of substrates comprising nano delicate substrates, substrates with nano-structured surface geometry, substrates with a catalytically active surface and catalytically inactive substrates with surface chemistry.