title: Synthesis of PVP stabilized Cu/Pd nanoparticles with citrate complexing agent and its application as an activator for electroless copper deposition.
abstract: A simple method has been developed to synthesize Cu/Pd nanoparticles in aqueous solution in ambient condition with the addition of complexing agent, trisodium citrate. UV-vis spectra confirmed the complexing behavior of trisodium citrate and metal ions. The particles synthesized with trisodium citrate were well dispersed with particle size ranging between 3-4 nm while the particles without trisodium citrate were larger and aggregated, as demonstrated by transmission electron microscopy (TEM). X-ray diffraction patterns (XRD) indicated the formation of bimetallic nanoparticles without impurities in the complexing agent-supplemented system. In contrast, large amounts of PdO and Cu(OH)(2) were precipitated along with the formation of particles in the complexing agent-free system. X-ray photoelectron spectroscopy (XPS) revealed small amounts of oxidized Pd on the surface of particles and the existence of zerovalent Cu and oxidized Cu in particles with trisodium citrate. With a simpler process for electroless copper deposition, the Cu/Pd nanoparticle activator with less Pd metal used exhibited comparable catalytic activity to conventional Pd/Sn colloidal activator. In summary, application of Cu/Pd nanoparticles synthesized with the complexing agent as an activator suggested a novel, simpler and inexpensive process in PCB industry.
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang Fu Road, Hsinchu City, Taiwan 300, ROC. d923618@oz.nthu.edu.tw
authors.forename: Sylvia H Y
authors.initials: SH
authors.lastname: Lo
authors.forename: Yung-Yun
authors.initials: YY
authors.lastname: Wang
authors.forename: Chi-Chao
authors.initials: CC
authors.lastname: Wan