1. Field of the Invention
The present general inventive concept relates to an inkjet head assembly of an inkjet printer, and more particularly, to an inkjet head assembly, which can reduce a print linewidth, and a printing apparatus and method using the inkjet head assembly.
2. Description of the Related Art
In general, inkjet printers are devices for printing a predetermined color image by ejecting a small volume of droplet of printing ink from a printhead at a desired position on a print medium. Printheads are largely categorized into two types depending on an ink ejection mechanism: thermal inkjet printheads in which a heat source is employed to form and expand bubbles in ink, thereby ejecting ink droplets, and piezoelectric inkjet printheads in which a piezoelectric element is deformed to exert pressure on ink, thereby ejecting ink droplets.
Inkjet printers have recently been applied to other fields as well as image forming apparatuses, for example, to printed electronics that manufactures electrical and electronic components, such as electrical wires or thin film transistors (TFTs), using printing technologies. Inkjet printers applied to printed electronics eject a functional ink, such as a metal ink or a conductive ink, onto a substrate from a printhead, thereby manufacturing electrical wires or electronic circuits. Electrical wires or electronic circuits are generally formed by lithography. However, lithography has a problem in that as a panel on which electronic devices are printed becomes large, large quantities of waste materials are generated, thereby increasing the risk of environmental pollution. In order to solve the problem, various attempts have recently been made to manufacture electrical wires or electronic circuits using inkjet printing.
A minimum ejection volume of currently marketed printheads is approximately 1 pl, thereby making it possible to obtain a minimum print linewidth of 10 μm or so. In order to highly integrate circuits, a print linewidth needs to be reduced below 10 μm. In order to obtain a print linewidth less than 10 μm, however, printheads need to have a minimum ejection volume of less than 1 pl. Even though such printheads are developed, the volume of ejected ink is so small that droplets of the ink may be blown into the air, thereby degrading the linearity of the ink droplets.