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Summary:
In this paper it is shown how the profile of an inkjet printed layer can be influenced. Inkjet printed layers on glass have often non-uniform layer thicknesses. Commonly known as the Coffee-Stain Effect, the profile shows higher thickness at the edges, but agglomerations in the center of a cross section are also possible. Especially for the functional printing industry these structures might lead to issues in subsequent processes, defects in top coatings or even to short circuits in electric components. One of the key goals of this paper is to control the uniformity of the profile. Therefore, a better understanding of the influence of solvents, evaporation and drying conditions is necessary. Different ratios of ethylene glycol and butanol mixtures were pipetted onto a glass substrate and were measured with a confocal microscope during drying. With a confocal microscope drying droplets were measured in a period from 15 minutes up to 36 hours. The results show new aspects of profile characterization and provide insights into the major impact of solvent composition due to the final film uniformity.