Preparation of highly conductive adhesives by insitu incorporation of silver nanoparticles

Abstract

In this paper, Ag nano-particles (Ag-NPs) with size of 50 nm, good stability and dispersion have been prepared via the tradition polyol method. Then, a small amount of this prepared nanosized Ag particles combined with the common used Ag micro-flake (Ag-MFs) were used as the conductive fillers to fabricate the isotropic electrically conductive adhesive (ICA). The content of the Ag-NPs on the electrical properties of the ICAs have been studied systematically. It is showed that, only a small amount of Ag-NPs, much lower than literature reported previously, can dramatically improve the electrical conductivity of the ICA based on Ag-MFs. The results indicated that for the 80wt% Ag-MFs filled ICA, after introducing 0.24wt% Ag-NPs, the volume resistivity of the samples could be reduced from 1.14 ×10-3 Ω·cm to 1.37×10-4 Ω·cm. ICA made by above method with the 70wt % Ag fillers have excellent overall performance with higher shear strength of 26.35 Mpa and a lower volume resistivity of 8.00×10-4 Ω·cm, which was considered to be an ideal ICA candidate for electronic packaging applications.