Fine Micro Patterning of Conductive Line by Using Direct Inkjet Printing

A novel selective metallization process to fabricate the fine conductive line based on drop-on-demand (DoD) inkjet printing was studied. Direct inkjet printing is an alternative and cost-effective technology for patterning and fabricating objects directly from design or image files without making masks and patterns. The conductive ink used in this experiment consists of 1 to 50 nm silver particles that are homogeneously suspended in an organic carrier. A piezo-electric inkjet print head driven by a bipolar voltage signal is used to dispense 20-40 mu m diameter droplets. Repeatability of circuitry fabrication is closely related to the formation of steady, satellite-free droplets. Therefore, the ability to form small and stable droplets with a same size, constant velocity and the correct flight angle must be taken into consideration for fine and precise conductive lines. In this study, parameters affecting the pattern formation such as drop formation, drop placement accuracy and velocity deviation between each nozzle have been investigated. As a result, direct inkjet patterning systems equipped with several functioning modules and fine metallic patterns have been developed.