ZHANG, Y., CHANGQING, L. and WHALLEY, D.C., 2012. The effect of droplet ejection frequency on the dimensions of inkjet-etched micro-via holes in poly4(-vinyl phenol) thin films. Journal of Physics D: Applied Physics, 45 (125303), 8pp.
The relationship between the size of inkjet-etched via-holes produced in poly4(-vinyl phenol)
thin films and the number of ethanol drops dispensed was established for a range of droplet
ejection frequencies. The physical mechanism underlying this relationship is proposed and the
dependence of the development of via-hole dimensions on the droplet ejection frequency is
believed to be attributable to the extent of evaporation of the solvent between two consecutive
drop dispenses. The results indicate complete penetration of the via-holes through the polymer
layer when produced at low droplet ejection frequencies. Electroplating was used to deposit
Cu into the created holes to further confirm the absence of polymer residue at low frequencies.
A threshold frequency, under which no via-hole enlargement occurs, has been found. The
study systematically focuses on the influence of droplet ejection frequency on the size of the
inkjet-etched via-holes versus the number of droplets used in poly4(-vinyl phenol) dielectric
thin films for printed electronics application.