Morphologies Control of Inkjet-printed Silver Lines by Substrate Temperature

The effects of surface properties of the substrate on the geometrical characteristics of inkjet-printed silver lines are investigated. Silver nanoparticle ink is printed on the paper and silicon wafers, which are frequently used as substrates of electronic devices. The microscopic three-dimensional structure is constituted by repeatedly printing of lines when the substrate temperature varies from 60 degrees C to 100 degrees C. The roughness of the substrate has no significant effects on the line morphologies while the substrate temperature is the major factor. Cross-section views of printed lines change from convex to concave shapes as the substrate temperature increases on both substrates. When the substrate temperature rises to 90 degrees C, the coffee ring effect begins to appear on the paper substrate but does not happen on silicon wafers. Further studies show that a small ratio of edge length to area or high surface roughness is helpful to reduce the occurrence of the coffee ring effect. Suitable morphologies of printed lines to improve the performance of electronic devices can be obtained by controlling surface properties of the substrate.