Profile Rod Technique: Continuous Manufacture of Submicrometer-Thick Ceramic Green Tapes and Coatings Demonstrated for Nanoparticulate Zinc Oxide Powders

Abstract

There is a fast‐growing market for printable electronics, which requires new techniques for micro‐ and nanofabrication suitable for mass production of functional electronic products. This makes the evaluation and comparison of different printing techniques highly important. In this work, a coating process, referred to as “profile rod technique,” is presented as an alternative to the spin‐coating process for the production of nanoparticulate zinc oxide (ZnO) layers with thicknesses of several hundred nanometers. Such layers could be used, e.g., as semiconducting layers for printed thin film transistors. The profile rod technique, in contrast to spin‐coating, is a continuous process, which allows for easier mass production and reduction in manufacturing costs. To compare the spin‐coating and the profile rod process, submicrometer‐thick layers of ZnO nanoparticle dispersions in ethanol were prepared. Different dispersion techniques were studied concerning their applicability for the manufacture of nanosized particle dispersions because well‐dispersed suspensions are the basic requirement for the manufacture of submicrometer‐thick layers with high morphological quality. The quality of the deposited layers was evaluated concerning their microstructure. Moreover, the profile rod technique could be successfully used for the manufacture of submicrometer ceramic green tapes.