Conductivity and foldability enhancement of Ag patterns formed by PVAc modified Ag complex inks with low-temperature and rapid sintering

Abstract In the research area of conductive inks for printed electronics, the preparation of conductive circuits generally shows high requirements on the process temperature, process efficiency, electrical conductivity, foldability and so on. In this paper, a new type of Ag complex conductive ink modified by PVAc (poly vinyl acetate) was proposed to enhance the conductivity and foldability of rapidly sintered Ag patterns. The conductive ink was fabricated by mixing silver oxalate as Ag precursor, 1,2-Diaminopropane as complexing reagent, methanol and isopropanol as organic solvents, and a small amount of PVAc as binding agent. Compared to the Ag complex ink without PVAc, the modified ink shows a better sintered microstructure with higher flatness and density after fast sintering at 140 °C–200 °C for 2 min, indicating that the addition of PVAc has a positive effect on the stability of Ag nucleation and microstructure formation. A low resistivity of 5.17 μΩ cm and an improved foldable property can be achieved at 180 °C by sintering the PVAc modified Ag complex ink on PI (polyimide) substrate, which indicates that the proposed ink is promised to be applied in printed circuits and flexible electronics.