Room temperature curable silica ink

Abstract

A facile formulation of room temperature curable silica ink screen printed on flexible and rigid substrate for printed electronic applications is presented. The colloidal stability and room temperature curability of the developed ink is controlled by optimizing the solvent, filler, dispersant and binder compositions. The printed ink has a porous microstructure with average surface roughness of 370 nm, and dielectric characterization of printed silica ink on BoPET film reveals relative permittivity (ε_r) of 3.2 and dielectric loss (tan δ) of 0.02 at 1 MHz, and values of the above parameters at microwave frequencies of 8.2–18 GHz vary from 2.4 to 2.3 and from 0.003 to 0.006, respectively, which is suitable for printed electronics. These findings suggest that the newly developed dielectric silica ink is cost effective and is curable at room temperature, which enables printing and curing of flexible electronic circuits in ambient conditions.