Fully inkjet-printing of metal-polymer-metal multilayer on a flexible liquid crystal polymer substrate

This study investigated a fully inkjet-printed metal/polymer/metal multilayer on a liquid crystal polymer substrate by using two alternately printed inks. A silver nanoparticle colloidal solution ink was used for the metal layers, and a dielectric-based SU-8 ink was used for the polymer layer. The conditions influencing the inkjet-printed polymer layer, including the surface treatment, drop spacing, and thermal treatment, were established; notably, surface wetting of the preceding layer, including various materials in the same level, affected the subsequent inkjet-printed layer. Thus, the conditions of thermal treatment should be carefully controlled to ensure an appropriately wet surface for printing. An inkjet-printed metal/polymer/metal multilayer was then fabricated using the determined printing parameters, and the results demonstrated the integrity of fully inkjet-printed technology. This success creates new feasible opportunities for electronic printing applications.