Relationship between the Conductivity of Isotropic Conductive Adhesives (ICAs) and the Lubricant Coated on Silver Filler Particles

Abstract

We investigated the relationship between the conductivity of isotropic conductive adhesives (ICAs) and silver (Ag) particles (filler) that are coated with different lubricants; high molecular weight fatty acid. The components of the ICAs are organic epoxy binder and silver filler. The conductivity of the ICAs was measured by a milliohm tester and the electron charge between silver particles was determined by powder charge amount measurements. The conductivity of ICAs differs depending on the kind of lubricant used, and there is a possible correlation between conductivity and the charge amount of silver particle in the samples. These results suggest that the conductivity of ICAs is not only a result of connections between the silver particles, but also of some interaction between the lubricants and silver particles. The silver filler particles in the ICAs appear to function as micro-capacitors in the cured state.