A Study on Micro-Electrode Pattern of Repair Process Using Electrohydrodynamic Printing System

Recently, various research studies have been conducted and many are in progress for the suitable alternative materials for ITO based touch screen panel (TSP) due to limitations in size and flexibility. Various researches from all over the world have been attempted to fabricate the fine electrode less than 5μm for the rapid developing of display technology. Research is also being carried out in metal mesh methods using the existing technologies and alternative materials at commercial level. However, by using the existing technologies certain discrepancies are observed like low transparency and low yield which also results in the distortion of patterns. For repairing the damaged pattern, the conventional laser CVD technique has also been used but there are some challenges observed in CVD technique like achieving a stable fine electrode of 10 μm or less and avoiding the formation of satellite drops. To overcome these issues, a new printing process named Electrohydrodynamic (EHD) printing, has been introduced by which 5 μm fine patterns can be printed in one step. This EHDA printing technique has been applied to print very fine electrodes of 5 μm or less by using conductive inks of various viscosities. This study also presents the optimized process parameters for printing 5μm fine electrode patterns during experiments by controlling the applied voltage and supply flow rate. The 5μm repair electrodes were fabricated for repairing 50 μm shorted electrode samples.