AC-pulse modulated electrohydrodynamic (EHD) direct printing of conductive micro silver tracks for micro-manufacturing

Abstract

This paper presents a direct fabrication of highly conductive silver tracks with sub-20 µm microstructures on glass substrates using electrohydrodynamic jet printing (EHD) based on alternative current (AC) voltage. A new AC-modulated EHD technique is presented and used in directly printing by generating a fine jet through a large electrical potential between the nozzle and substrate. In the presented technique of AC-modulated EHD, when charge accumulates on the ink meniscus at the nozzle, a fine jet down to nano scale can be generated. The variables of fabrication process, like plotting speeds, curing temperature and number of layers, were investigated to achieve reliable jet printing of conductive silver tracks. Topography and electrical property of printed tracks were characterized and verified. By using modulated AC-pulsed voltage, we are capable of printing high resolution continuous patterns on insulating substrates. In the study, we successfully applied EHD for fabrication of highly conductive silver tracks on glass substrate. It was the first time that sub-20 µm silver tracks were demonstrated with resistivity about 3.16 times than bulk silver. The presented technique can be used for direct printing of micro scale electronic circuits and devices.