The effect of ultrasonic excitation on the electrical properties and microstructure of printed electronic conductive inks [poster]

Ultrasonic Additive Manufacturing (UAM) is an emerging unique manufacturing technique, which enables the embedding of electronic components and interconnections inside solid aluminium structures. The effect of ultrasonic excitation and the UAM process parameters on the electrical properties and the microstructure of thermally cured screen printed silver conductive inks and the role of the insulating layer between the conductive tracks and the aluminium substrate, were investigated. The electrical resistance and the dimensions of the samples were measured and compared before and after the ultrasonic excitation. The microstructure of exited and unexcited samples was examined using optical microscopy and SEM/FIB imaging. The results suggested that ultrasonic excitation increased the resistivity of the samples, but the tracks retained their conductive properties. The material of the insulating layer had the largest effect on this phenomenon. Moreover, the microstructure appeared to become courser, suggesting that bonding between the silver particles of the ink may have occurred.