Effects of silver oxide addition on the electrical resistivity and microstructure of low-temperature-curing metallo-organic decomposition silver pastes

Abstract

The thermal decomposition of silver paste with the addition of a metallo-organic decomposition (MOD) compound generally requires a curing time of greater than 10 min and a curing temperature greater than 250 degrees C, which does not meet the requirement for high-speed production in flexible substrates. In this study, attempts to modify the curing conditions of MOD silver pastes through the substitutions of silver flakes with silver(I) oxide (Ag2O) and silver(II) oxide (AgO) were performed. Differential thermal analysis (DTA), derivative thermogravimetric analysis (DTG), and X-ray diffraction (XRD) results indicated that the presence of residual silver oxide, which effectively catalyzes the evaporation of a-terpineol and the decomposition of silver 2-ethyl hexanoate, decreases the curing temperature and shortens the soaking time. The reduced silver and the remaining AgO enhance the connectivity and packing density of the silver flakes, and thus increase the electric conductivity of the films. For films prepared from pastes with 20 wt % Ag2O or AgO, resistivities of 14 x 10(-6) and 19 x 10(-6) mu Omega center dot cm. respectively, were successfully achieved after being cured at 200 degrees C for 5 min.