Screen-printed thick-films: From materials to functional devices

The aim of the present paper is to demonstrate that the existence of a bulky sintered material, with the required properties for a potential application (called hereafter active material), does not necessarily mean a straightforward manufacturing of a corresponding functional planar thick-film device with the required properties. Many problems have to be solved at the level of each element of the micro-assembly, namely the substrate, the electrodes, the heating resistor, and of course the active material. Moreover, for a reliability approach, physico-chemical interactions in the whole micro-assembly have to be considered. Examples drawn from our own experience in the area, deal with super-thick copper pads, varistors, PZT-based pyroelectric sensors, semiconductor oxide gas sensors, zirconia oxygen sensors ….