잉크 솔벤트와 기판 조건이 잉크젯 분사 패턴의 형상에 미치는 영향

Abstract

To reveal the effect of ink solvents and substrate conditions on shapes of patterns, inks and substrates with different properties and various conditions, respectively, were applied to remove a coffee ring effect and a bulging effect. This work discussed the comparison of different shape change results, solvent evaporating temperature, surface energy and heating temperature of substrate on shapes of inkjet-printed patterns. To obtain a hydrophobic surface, a fluorocarbon (FC) film was spin-coated on a silicon substrate. Subsequently, the surface energy was increased by performing an ultraviolet ozone (UV/O3)treatment and the end, to reduce merging of deposited droplets which heat the substrate from room temperature to 80 oC during the jetting process. The surface energies of the substrate remarkably changed from 11.9 mN m− 1 in the initial status to 41.8 mN m− 1 for a 6 min UV/O3 treatment time. The change of surface energy and temperature are not directly related to exclusion effect of the coffee ring effect and the bulging effect. Ink solvent having higher boiling temperature above 250 oC shows a coffee ring effect and a bulging effect while ink solvent having lower boiling temperature below 100 oC is not. As a result, selecting a proper solvent for silver ink is one of the most promising methods of controlling the shape of the silver inkjet-printed patterns. The coffee ring and the bulging effects could be successfully reduced by selecting an appropriate primary solvent having low evaporating temperature. These results founded in this work would be applicable to other inkjet-printing technology.