Fabrication of binary Ag-based conductive paste with high electrical conductivity and bending resistance for flexible printed electronics

A binary micro-nano graded silver-based low temperature conductive composite paste was developed for printing conductive patterns on flexible substrates.The conductive phase includesmulti-scale flake and spherical silver powders, with bisphenol F epoxy resin as the binder. Butyl butyrate, 2-(2-butoxyethoxy) ethanol, and diethylene glycol monobutyl ether acetate were selected as organic solvents. Using DSC, TG, surface morphology, viscosity, and resistivity analyses, we investigated the effects of these solvents with different boiling points on the conductivity and curing behavior of the low temperature paste. After screen-printed onto polyimide film, the paste demonstrated low resistivity (3×10 –5 Ωˑcm) and robust mechanical stability.Its resistance increased from 1.4 Ω to only 1.5 Ω after 3000 bending cycles. The adhesion strength of the printed pattern was assessed via a tape test.The pasteshowedgood comprehensive performance, when applied in thin-film switches and light-emitting logo devices. These results highlight its potential for flexible electronicsapplications and provide valuable insights for advancing flexible conductive circuits.