Effects of Solvent Type on Low-Temperature Sintering of Silver Oxide Paste to Form Electrically Conductive Silver Film

摘要

Silver oxide pastes were formulated from silver oxide powder, silver alpha-neodecanoate, and solvents, which lowers the sintering temperature of printed silver films to 150 deg C. In this paper, solvent effects were investigated through the formulation of silver oxide pastes using various solvents with high boiling points such as glycol, ether, and terpineol. Solvent structures such as terminal methyl and alkoxyl groups affected the solubility of silver alpha-neodecanoate and the swelling of the polydimethylsiloxane (PDMS) blanket. Particularly, higher solubility induced uniform mixing of the silver oxide powder and silver alpha-neodecanoate, which resulted in higher conductivity after sintering. Glycols and monoalkyl ethers reacted with the silver oxide or silver salt, which deteriorated the pot life of the paste. Among the various candidates, alpha-terpineol satisfied all the requirements such as printability and stability, exhibiting a solubility of 47.8 g in 100 g of solvent, PDMS swelling of 4.6percent, and conductivity of 1.8 X 10~(5) S/cm after sintering at 150 deg C for 30 min.