Enhancing the Electrical Properties of Inkjet-Printed Silver Ink by Electrolyte Sintering, Photonic Sintering, and Electroless Plating

Abstract

Conductive inkjet printing is an emerging rapid manufacturing technology in the field of smart clothing and wearable electronics. The current challenge in conductive inkjet printing includes upgrading of electrical performance of printed inks to the equivalent level to traditional conductors such as bulk silver and copper, especially for high-performance electronic applications such as flexible antennas and circuits. Post-treatments are commonly employed to enhance the electrical conduction of inkjet-printed tracks. This research discusses the effects of electrolyte sintering, photonic sintering and electroless copper plating on the DC electrical resistance and resistivity of inkjet-printed silver nanoparticles. From experimental results and measurements, it was found that all the post-treatment methods effectively improved the electrical properties of printed silver ink, but in different ways. The lowest resistance of 4.5 Ω (in 0.1 mm × 10 mm) and thickest (4.5 μm) conductor were achieved by electroless copper plating, whereas the lowest resistivity (7.5×10-8 Ω•m) and thinnest (1.0 μm) conductor were obtained by photonic sintering.