Printing Contractive Silver Conductive Inks Using Interface Interactions to Overcome Dewetting

Abstract

Surface energy incompatibility between ink and substrate is a significant obstacle for inkjet printing of electronic components, causing printed lines to dewet and break apart. In this work it was demonstrated that smooth, continuous silver lines could be printed via control of ink-substrate interactions, despite the tendency of the ink to dewet from the substrate. The silver lines were printed using drop-on-demand inkjet printing of silver nanoparticle ink onto un-crosslinked SU-8 coated polyethylene terephthalate (PET). The lines were subsequently heated to control dewetting and cause contraction from 60 µm to 18 µm. The SU-8 film underneath the silver line was dissolved and redistributed and formed a ridged concave structure that prevented the lines from bulging and breaking apart.