UV-curable silver inks and paste for electronic devices

초록

UV-curable Ag inks and pastes have been investigated intensively because they can be widely applied in bus/address electrode patterns for plasma displays (PDP) and polymer thin film transistor (TFT), circuit patterns for 3-D micro electromechanical systems (MEMS) and radio frequency identification (RFID), and grid patterns for photovoltaic cells. In this study, we prepared Ag complex ink (Ag-CI), Ag particle ink (Ag-PI), and their pastes from Ag-neodecanoate (Ag-ND). Ag-film for conductivity measurement was fabricated by spin coating method using Ag inks on polyimide substrate. The patterns using Ag-ND paste were obtained on a glass substrate by the screen printing method. The properties of Ag films were characterized by SEM, XRD, and 4-point probe analysis. SEM images of cured films indicated that Ag-CI and Ag-PI on polyimide film got agglomerated and grain growth to larger silver particles after UV-irradiation. XRD pattern of cured Ag-CI film showed diffraction peaks at 2Θ of 38, 44, 64, 77° indicating the face-centered cubic (FCC) structure (JCPDS 04-0783) of typical silver. The increase in irradiation time and the decrease in irradiation height made the peak of XRD patterns sharper showing better crystalinity of silver nanoparticles formed. After UV-irradiation at 10cm of height, sheet resistances of Ag films using Ag-CI, -PI, and pattern with Ag-paste were 0.094 Ω/□, 0.358 Ω/□ and 371 mΩ/□, respectively. In conclusion, UV-curable Ag inks and pastes developed in this study would be a good alternative for electronic devices with the low sintering temperature and can be widely used to flexible display technology.