Application of Silver Nitrate Solution and Inkjet Printing in the Fabrication of Microstructural Patterns on Glass Substrates

Aqueous silver nitrate inks of 1, 5, and 10 mol/liter (M) were employed in a piezoelectric inkjet printing apparatus to construct microstructural patterns. On the basis of droplet observation, single droplets of silver nitrate inks were ejected at a suitable pulse amplitude of waveform. The characteristics of drying processes for silver nitrate solutions were investigated after measuring the contact angle on the prepared glass substrates. Because of the crystallization of silver nitrate, the decrease of local surface tension was induced with decreasing solute concentration. In addition, local surface tension was possibly reduced by exothermal reaction during the formation of crystal solid. The actual printing qualities of array and line patterns were then analyzed by variation of dot interval and substrate temperature. The pure silver patterns were reduced by ethylene glycol vapor at 250 degrees C for 10 min. Unsteady spreading features of printed array and line patterns on hydrophilic glass are found to be due to silver nitrate crystal during droplet drying, which is dominated by solute concentration and substrate temperature. Optimal printing quality with a continuous morphology of fine lines was generated successfully with a dot interval of 40 mu m and an average line width of 90 mu m at substrate temperature of 90 degrees C.