Abstract: A process for fabricating electronic switching elements and/or circuits in multilayer thick-film technology on a substrate. The electronic switching elements and/or circuits are printed onto the substrate in the form of liquid or pasty mixtures of materials, then heat-treated, whereupon at least one insulating layer is deposited on the thick-film conducting layer. In this process, the surface of any desired insulating interlayer is finished abrasively and subsequently again at least one thick-film conducting layer or at least one insulating layer is deposited on the finished surface. Then, the surface or this insulating layer is again finished abrasively in subsequent printing operations of thick-film conducting layers or in other insulating layers in order to provide upon completion each layer at least the same processing ingredients and conditions as those on the surface of the substrate.

Abstract: A method of printing and checking a printing image, e.g., bar codes, of a thermoprinter. The just-printed printing image is scanned after printout of a portion of the printing image on the paper web by means of an opto-electronic sensor which can move relative to the paper web, reading the just-printed printing image in the process. The read result is compared and checked with the originally entered data and, if an error is detected, the remainder of the printing image still to be printed or the just-printed printing image is marked by the printer as unusable, e.g., blackened.