Forming conductive metal patterns using water-soluble copolymers

A method for forming a pattern in a polymeric layer, the method comprising:

• providing a polymeric layer comprising a reactive composition that comprises:
• (1) a reactive polymer that is metal ion-complexing, water-soluble, and crosslinkable, which reactive polymer comprises pendant photosensitive, non-aromatic unsaturated carbocyclic groups and (2) optionally, a photosensitizer,
• patternwise exposing the polymeric layer to radiation having a λmax of at least 150 nm that is sufficient to provide at least partial crosslinking within the reactive polymer, to provide a polymeric layer comprising non-exposed regions and exposed regions comprising a crosslinked polymer derived from the reactive polymer,
• optionally heating the polymeric layer simultaneously with or after patternwise exposing the polymeric layer but before removing the reactive composition comprising the reactive polymer in the non-exposed regions, at a temperature sufficient to further crosslink the crosslinked polymer in the exposed regions of the polymeric layer,
• removing the reactive composition comprising the reactive polymer in the non-exposed regions,
• contacting the exposed regions of the polymeric layer with electroless seed metal ions to form a pattern of electroless seed metal ions in the exposed regions of the polymeric layer,
• reducing the pattern of electroless seed metal ions to provide a pattern of corresponding electroless seed metal nuclei in the exposed regions of the polymeric layer, and
• electrolessly plating the corresponding electroless seed metal nuclei in the exposed regions of the polymeric layer with a metal that is the same as or different from the corresponding electroless seed metal nuclei.