Preparation of nano-silver conductive ink and its application in high-precision flexible circuit printing

Abstract:

Two kinds of ink-jet printing conductive inks were prepared with silver nanoparticles and silver nanowires as conductive components, byk-333 as surface additive and ethylene glycol as solvent respectively. The conductive lines were printed on the flexible transparent substrate by micropltter II micro nano deposition system. The effects of printing process, thermal sintering curing and packaging on the conductivity, weather resistance and interference of the two printing circuits were studied. The results show that the diameter of printer nozzle and the contact angle between ink and substrate are the key factors to determine the linewidth accuracy of conductive circuit. Thermal sintering treatment can improve the conductivity of silver nanoparticle flexible circuit. When sintered at 160 ℃ for 30 minutes, the resistivity decreases to 16.4 μ Ω. cm, keep the conductivity unchanged after being placed in the air for 90 days, and the resistivity increases by 12.4% after 1000 bends; With the increase of printing times, the conductivity of the silver nanowire printing circuit continues to increase. The unit resistance of the printing line obtained by printing 9 times is 88.9 Ω /cm. With the increase of sintering temperature and time, the conductivity of the circuit decreases. PDMS packaging can greatly improve the stability of the printing circuit. After being placed in the air for 90 days and bent for 1000 times, the conductivity remains unchanged, It shows that conductive ink based on silver nano materials and micro nano deposition system can achieve stable printing of high-performance and high-precision flexible circuits.

Key words:silver nanoparticles; silver nanowires; conductive ink; inkjet printing