Using a functional epoxy, micron silver flakes, nano silver spheres, and treated single-wall carbon nanotubes to prepare high performance electrically conductive adhesives

Abstract

In this study, a matrix resin containing a functional epoxy, a reactive diluent, a silane-coupling agent, and a curing agent was used to fabricate three modal electrically conductive adhesives (ECAs) with micron silver flakes, nano silver spheres, and treated single-wall carbon nanotubes (CNT). Results showed that too many micron silver flakes reduced the bulk resistivity and adhesion strength of uni-modal ECAs (matrix resin and micron silver flakes). As the nano silver spheres increased, the bulk resistivity of bi-modal ECAs (matrix resin, micron silver flakes, and nano silver spheres) firstly decreased, and then increased again. The adhesion strength decreased also. The bulk resistivity and adhesion strength of tri-modal ECAs (matrix resin, micron silver flakes, nano silver spheres, and treated CNT) both were reduced by the treated CNT greatly. These ECAs could be cured at 120°C or any higher temperature than this with different curing time. They all had high temperature stability with a pyrolysis temperature above 350°C and a glass transition temperature around 180°C.