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Palladium chloride as a pre-cursor for silver deposition

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Could anybody assist me with information regarding successive process steps of stannous chloride then palladium chloride as a pre-cursor to silver deposition on non-conductive substrates?

David Bamber
UK

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This can probably be done, but it is an unusual mixing of technologies. There are three different wet processing technologies that are commonly used to metallize non-conductors.

1). Applying a two-part silver reduction system. In this approach, a soluble silver salt and a reducing agent are simultaneously sprayed onto the substrate to deposit metallic silver. This is done as the first step in making stampers for vinyl records.

2). Applying a colloidal suspension of conductive granules, which can be graphite, copper, or silver. This is more or less painting the part with a conductive silver paint, and is often used to metallize flowers, leaves, and things like that.

3). The palladium chloride / stannous chloride system which is used to precede electroless copper or electroless nickel deposition on plastics, for use on such things as automotive brightwork.

I suppose it is possible to follow routine #3 with electroless copper, followed by electrolytic copper, and then electrolytic silver. However, this is done (to my knowledge) exclusively with proprietary sequences. You might want to talk to Enthone/OMI, Atotech, Shipley, or MacDermid.

I think you would also find the book "Standards and Guidelines for Electroplated Plastics" to be a big help.

Ted Mooney, P.E. finishing.com Brick, New Jersey