Preparation and properties of particle-free silver conductive ink suitable for low temperature sintering process.

Conductive ink is the key to the development of flexible printed electronics. However, at present, the sintering temperature of conductive ink is still high, which restricts its use in some flexible substrates. This paper reported a kind of non-granular silver conductive ink which can be sintered at low temperature. The particle-free silver conductive ink was prepared from silver acetate using ammonia as the complexing agent, ethanol as an auxiliary agent and formic acid as a reducing agent. The obtained conductive ink droplets were coated on PET substrate and then sintered into film in an oven. The conductive ink and film were characterized by means of X-ray diffractometer (XRD), scanning electron microscope (SEM), Fourier infrared spectrometer (FTIR) and other methods. The effects of formic acid and ethanol on the properties of the conductive ink and film were systematically investigated. The results show that the conductive ink has good stability. After sintered at 90 °C for 60 min, its resistivity is 11.83 µΩ cm. By adjusting the ink formula, the roughness and uniformity of silver film can be improved significantly and the film will exhibit good bending performance. [ABSTRACT FROM AUTHOR]