Printing Silver Conductive Inks with High Resolution and High Aspect Ratio

Abstract

Abstract Narrow metal lines with low electrical resistance are essential for many printable electronic devices. Printing metal lines of narrower than 10 µm and with a high thickness‐to‐width aspect ratio is very difficult and remains a technical challenge in printable electronics. In this work, by controlling the ink–substrate interaction and ink drying dynamics, 4.6 µm wide inkjet‐printed silver lines are demonstrated with an aspect ratio of 0.7 and an elliptical cross‐section. The silver lines are obtained by jetting a silver nanoparticle‐based ink onto an SU‐8‐coated polyethylene terephthalate substrate to form well‐defined silver lines, and then heating the lines to transform them into high aspect ratio narrow lines through ink dewetting and receding. The simultaneous dissolution and redistribution of SU‐8 by the ink result in a concave structure, which prevents the lines from bulging and allows the lines to become embedded into the SU‐8 film.