Sustainable-Ink Process Recipes for the Fabrication of Additively Printed Circuits and Component Attachment

The present generation of additively printed electronics inks used to realize conductive circuits are composed of nano-particles in volatile solvents such as isopropyl alcohol, xylene, methyl-ethyl-ketone, formic acid, ethyl alcohol, polyvinyl pyrrolidone (PVP), and sodium borohydride. Environmental, social, and geographic factors have become increasingly important for electronics manufacturing owing to high volumes and increased attention to sustainability. Water-based inks have emerged for achieving conductive circuits using additive processes. Little is known about the water-based formulations related to the process-performance-reliability interactions. The performance and reliability of water-based ink-printed circuits with surface-mount devices are not well understood. In this paper, the process-performance-reliability interactions have been studied for three print platforms using water-based low-environment impact waste inks for the realization of circuits. The print platforms studied include aerosol-jet, inkjet, and direct-write. The effect of downstream thermal exposure has been studied using the design and testing of surface mount circuits on all three print platforms. The component attachment has been achieved through low-temperature solders, and electrically conductive adhesives. The evolution of resistance and shear load to failure has been studied on all three print platforms for post-attachment and pre-attachment circuits. The applications demonstrated include signals and amplification. The reference circuits include comparative designs using volatile organic compound-based inks.