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

Abstract

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.