Nickel and copper conductive patterns fabricated by reactive inkjet printing combined with electroless plating

• Patterned metal structures formed by reactive inkjet printing and electroless plating.
• The obtained metal structures possess excellent adhesion to polymeric substrates.
• Obtained patterns possess good resistance stability during 20,000 bending cycles.
• Suggested technique is simple, low-cost and easy scale-up.

A simple, low-cost and easy scale-up technique for fabrication of conductive interconnects for flexible electronic devices is presented. A thin seed layer of nickel or copper was formed on the surface of PEN substrate via reactive inkjet printing of metal salt and reducing agent instead of traditional seed layers such as palladium nanoparticles and palladium or silver salts. For deposition of a uniform metal coating a polymer substrate patterned with the seed layer was immersed in an electroless plating bath. The electrical resistivity of deposited nickel–phosphorus and copper layers was 3.8±0.2 mΩ·cm and 29±2 µΩ·cm, respectively. The obtained structures possess excellent adhesion to polymeric substrates and reveal only slight decrease of conductivity after 20,000 bending cycles.