A Novel Method for Fine Patterning by Piezoelectrically Induced Pressure Adjustment of Inkjet Printing

In this paper, a method is proposed for fine line pattern formation on polyimide films by drop-on-demand inkjet printing without the need to reduce the nozzle size. The rapid change in the shape of a piezoelectric actuator caused by a pressure wave causes the fluid to be ejected as droplets. By shortening the duration of the chamber compression period, smaller droplets can be ejected from the nozzle orifice. The pressure wave is a key factor in determination of the line width. A 20-µm-wide line pattern pulsed at 0.5 µs intervals was successfully fabricated using a Cu complex ion ink and a cartridge with volume of 1 pl. This method is expected to be widely used in various applications that demand high-resolution patterning. The 20-µm line width of the conducting track is a particularly useful size for fabrication of transparent electrodes.