Low-temperature silver sintering by colloidal approach

Abstract

The interest of silver nanostructures has surged in recent years as they are becoming promising materials in a growing number of applications. In particular, they have received intense attention for their use as lead-free die attach materials, photoactive devices engineering or more broadly electronic packaging. One of the challenges is the elaboration of conductive and printable patterns by Low-Temperature and Pressureless Sintering Techniques (LTPST) to achieve electric circuits on heat-sensitive substrates such as paper, plastic, polymeric substrates. Here, we present a facile method for synthesizing conductive patterns at low temperature based on the formation of self-assembled Ag nanocubes on Active Metal Brazing (AMB) substrates. The elaboration of 3-D arrays with nanogap of 2-3 nm between the cubic building units allows to get dense and compact packed nanoparticle solids which sinter at lower temperature than conventional commercial silver pastes. The impact of the capping agent and the size of the building units on the sintering properties were investigated and discussed.