Synthesis of vinyl acetate/Pd nanocomposites as activator ink for ink-jet printing technology and electroless copper plating

A novel method for the preparation of palladium (Pd) nanoparticles reduced by vinyl acetate (VAc) oligomers is presented in this study. VAc was synthesized by free radical polymerization method which was based on vinyl acetate/potassium persulfate (KPS)/water system. The noble metal nanoparticles reduced and stabilized by vinyl acetate oligomer showed their well dispersion in the aqueous solution without surfactant and reductant in the mixture. These Pd nanoparticles can be used as activator to replace the traditional Pd/Sn colloid for electroless metal deposition. Based on our results, the coverage of Cu layer completely on substrate was achieved after 30 min deposition at 75 °C. The ink based on VAc/Pd colloids was successfully inkjet printed onto a FR-4 plate. The formed metallic palladium patterns were subjected to electroless copper plating, yielding well-defined copper lines. This process provides a clean, easy and low-cost method for preparation of high resolution Cu patterning.