Electrohydrodynamic (EHD)-jet printing is a very powerful tool and process for the direct patterning of the functional materials on a large variety of substrates. Its ability to do patterning as well as thin film deposition can help in fabrication of the electronic devices such as TFT, OLED or Solar Cells and so on through a single technology. EHD-jet printing can provide simple patterning and complex patterning with better resolution than ink-jet technique. Moreover, it can produce any pattern with a charged ink formulation with less viscosity dependence.
In this study, silver and copper pastes were formulated to obtain cone jet mode of EDH-jet printer. Due to high viscosity and thixotropic properties of silver and copper paste, direct pattering was not possible. New additive was found to modulate the cone jet mode of EHD jet. Many parameters were examined to obtain desired solid and straight line patterns by an EHD-jet printing process. The sharp and continuous lines with the width of 80 mm or less were obtained using a commercially available steel needle without any treatments, with a robust and simple process.