Facile synthesis of silver malonate conductive MOD ink for screen printing

At present, screen printing is the most widely used technique in the printed electronics industry and the printed pattern can satisfy certain electronic application requirements. Ink development is the most important part of the printing process. In this paper, a new particle-free MOD ink (MOD = metal–organic-decomposition) was synthesized from silver malonate, diethanolamine (DEA) and ethylene glycol (EG). Silver malonate was the precursor of silver. DEA was the complexing agent that maked silver malonate soluble. EG acted not only as a solvent to regulate the rheological properties of the ink, but also as a reducing agent to reduce silver ions. The decomposition temperature was reduced from 210 °C to about 100 °C by the formation of silver-amine complex, thus the selection range of substrate could be broadened. The ink was spread on the polyimide (PI) substrate by screen printing. The silver film was formed after heat treatment at 150 °C for 1 h and its electrical conductivity can reach 1.0 × 104 S cm−1, which corresponded to one sixty-third of the theoretical conductivity of the bulk silver (6.3 × 105 S cm−1).