Abstract: External electrodes on piezoceramic multilayer actuators, composed of a layer of a basic metallization applied to the ceramic material of the surface of a actuator, to which metallization there is joined by means of a joining layer a reinforcing layer to which a connecting wire is soldered, wherein the layer of basic metallization is structured by discontinuities or recesses.

Abstract: In the case of external electrodes on piezoceramic multilayer actuators that are applied in a conventional manner to the multilayer actuators, severe tensile stresses act on the insulating region underneath the basic metallization during operation. Since said insulation region forms a homogeneous unit together with the basic metallization and the joining layer, the latter breaks down when the tensile strength of the weakest member is exceeded and cracks are formed. The cracks extending in an uncontrolled manner through the insulating region are very critical since they reduce the insulation spacing and considerably increase the probability of an actuator failure due to flashovers.