Ag dot morphologies printed using electrohydrodynamic (EHD) jet printing based on a drop-on-demand (DOD) operation

Abstract

Electrohydrodynamic (EHD) jet printing technology is an attractive method for micro-scale electronic device fabrication. The primary advantage of EHD jet printing compared with conventional inkjet printing is the capability to print at resolutions below 10 µm and to eject high-viscosity ink. In this study, by using drop-on-demand (DOD) jetting, we printed silver (Ag) dots onto a silicon (Si)-wafer and evaluated the dot uniformity. Furthermore, we investigated the effects of substrate surface energy and substrate temperature on the dot morphology. We also investigated the effects of overprinting on the dot morphologies. Our results show that we successfully created uniform dot patterns under 10 µm by using EHD jet printing. In addition the dot diameter approached 14 µm while the substrate was heated up to 40 °C. We also found that on the hydrophobic Si-wafer, increasing the substrate temperature and the number of overprinting could be used as an alternative method for increasing the aspect ratio of dot and suppressing the coffee-stain effect.