Fine Metal Line Patterning of ITO Ink Based On Electrohydrodynamic Printing

This paper reports the successful electrohydrodynamic (EHD) printing of about 2-to 20-mu m width of metal line patterns, with the line thickness over 30 nm on a glass substrate and coated silicon nitride surface for the repair of TFT pixel. With fine metal line patterning based on EHD printing related to optimize the parameters (e.g., the distance between the substrate and the nozzle, the speed of the moving stage, as well as the applied voltage and pressure), we can be successful in the EHD printing of the desired line width and thickness. To find the optimal setting of parameters, extensive experiments were conducted under various parameter settings. We achieved a 2.0 +/- 0.5 mu m width of ITO metal line patterns, with the line thickness of over 30 +/- 10 nm on a coated silicon nitride surface for the repair of TFT. In order to verify the electrical characteristics of the patterned ITO line by EHD printing, we printed the line with 20-mu m width. The resistance of the line with 20-mu m width was measured to be 190 KO, convertible to the electrical resistivity of 46.8 m Omega.cm.