Additive Manufacturing Technologies Compared: Morphology of Deposits of Silver Ink Using Inkjet and Aerosol Jet Printing

We report about a detailed comparison of the additive manufacturing methods inkjet printing (IJP) and aerosol jet printing (AJP). Both technologies are based on the direct-writing approach enabling the non-contact deposition of various materials in flexible patterns, e.g., for printed electronic applications. The deposited pattern elements were classified as (i) drops (IJP) or splats (AJP), (ii) lines, and (iii) squares. These elements can be considered as basic elements of the deposition systems and also of printed electronics. The pattern elements were deposited with IJP and AJP using the same silver nanoparticle ink. After printing, the layers were characterized regarding their morphology by optical and topographical measurement methods as well as regarding their electrical characteristics. It turned out that drops deposited with IJP and splats deposited with AJP can have similar dimensions. However, the shapes of the deposits differ widely. In the case of lines, AJP enables narrower line widths and thinner line thicknesses in comparison to IJP. In IJP, the line morphology varies depending on the direction of the deposition. Finally, the morphology of the deposited lines determines the electrical conductivity. For printed squares, the IJP layers show much higher layer thickness and a different layer topography compared with AJP as result of a higher volume per area deposition of materials.