AgNO3 flux on the polymer-coated Al2O3 substrates and application in the fabrication of patterned Ag electrodes

•The behaviors of melting AgNO3 on original and polymer-coated Al2O3 substrates were observed in-situ.•The spreading of AgNO3 flux was confined by “pinned” rim on poly(acrylic acid)-coated Al2O3 substrate.•Nozzle-block-free ink was used to fabricate high-resolution Ag electrode by inkjet printing technique. The behaviors of melting AgNO3 on original and poly(acrylic acid)-coated Al2O3 substrates were studied through in-situ observations. The spreading of AgNO3 flux on polymer-coated substrate was confined by “pinned” rim and high-resolution inkjet-printing silver electrode with clear boundary was fabricated after a rapid heat treatment.