Uniformity of fully gravure printed organic field-effect transistors

Fully mass-printed organic field-effect transistors were made completely by means of gravure printing. Therefore a special printing layout was developed in order to avoid register problems in print direction. Upon using this layout, contact pads for source–drain electrodes of the transistors are printed together with the gate electrodes in one and the same printing run. More than 50,000 transistors have been produced and by random tests a yield of approximately 75% has been determined. The principle suitability of the gravure printed transistors for integrated circuits has been shown by the realization of ring oscillators.