Reduction synthesis of silver nanoparticles anchored on silver micro-flakes and electrical resistivity of isotropic conductive adhesives at percolation threshold

Reduction synthesis of silver in an ethanol solution without polyvinyl pyrrolidone was performed to anchor synthesized nanoparticles on micro-sized silver flake surfaces in order to enhance the electrical conductivity of isotropic conductive adhesives (ICAs). Although some shape-separated silver particles were formed, the synthesis of particles anchored on the flake surfaces was successful. The cured ICAs containing the silver flakes anchored with 1 wt. % nanoparticles indicated enhanced electrical conductivity due to their filling the gaps between noncontacting silver flakes at the beginning region of the percolation threshold. However, the anchored nanoparticles had a detrimental effect on the conductance when the content of anchored nanoparticles or flakes was higher.