A novel Co-casting process for piezoelectric multilayer ceramics with silver inner electrodes

Abstract

The presented process offers a simplified method for manufacturing multilayer ceramics (MC) in comparison to the conventional multilayer ceramics technology (MCT). It combines the tape casting of ceramic green tapes and the subsequent screen printing of electrodes into one single co-casting process. Since the co-casting process circumvents also the stacking and laminating of single ceramic green tapes, MC with layer thicknesses as thin as 20 μm could be manufactured by this technique. To create an easy contacting of the inner electrode in the MC, the generation of an interdigital electrode structures has been aspired. By means of the specific innovation, to fix a shadow mask by magnetic forces on top of the ceramic green tape, this was realized. With the intention to manufacture piezo generators for vibration energy harvesting, triple-layered bending transducers have been manufactured successfully from a hard-doped PZT powder and inner electrodes made of pure silver via this new cocasting process. The material compatibility for the co-firing step of PZT and the cost-effective base metal silver was achieved by means of the liquid phase sintering technology, using a combination of Li2CO3·Bi2O3·CuO (LBCu) as sintering additives.