Base Metal Co-Fired Multilayer Piezoelectrics

Lisheng Gao, Hanzheng Guo, Shujun Zhang, Clive Randall
2016 Actuators  
Piezoelectrics have been widely used in different kinds of applications, from the automobile industry to consumer electronics. The novel multilayer piezoelectrics, which are inspired by multilayer ceramic capacitors, not only minimize the size of the functional parts, but also maximize energy efficiency. Development of multilayer piezoelectric devices is at a significant crossroads on the way to achieving low costs, high efficiency, and excellent reliability. Concerning the costs of
more » ... osts of manufacturing multilayer piezoelectrics, the trend is to replace the costly noble metal internal electrodes with base metal materials. This paper discusses the materials development of metal co-firing and the progress of integrating current base metal chemistries. There are some significant considerations in metal co-firing multilayer piezoelectrics: retaining stoichiometry with volatile Pb and alkaline elements in ceramics, the selection of appropriate sintering agents to lower the sintering temperature with minimum impact on piezoelectric performance, and designing effective binder formulation for low pO2 burnout to prevent oxidation of Ni and Cu base metal. Abstract: Piezoelectrics have been widely used in different kinds of applications, from the automobile industry to consumer electronics. The novel multilayer piezoelectrics, which are inspired by multilayer ceramic capacitors, not only minimize the size of the functional parts, but also maximize energy efficiency. Development of multilayer piezoelectric devices is at a significant crossroads on the way to achieving low costs, high efficiency, and excellent reliability. Concerning the costs of manufacturing multilayer piezoelectrics, the trend is to replace the costly noble metal internal electrodes with base metal materials. This paper discusses the materials development of metal co-firing and the progress of integrating current base metal chemistries. There are some significant considerations in metal co-firing multilayer piezoelectrics: retaining stoichiometry with volatile Pb and alkaline elements in ceramics, the selection of appropriate sintering agents to lower the sintering temperature with minimum impact on piezoelectric performance, and designing effective binder formulation for low pO 2 burnout to prevent oxidation of Ni and Cu base metal. Actuators 2016, 5, 8 2 of 21 the piezoelectric industry has been continually suffering from the high costs of precious metal electrodes. Additionally, manufacturing multilayer actuators is different from that of multilayer ceramic capacitors (MLCC), which have industrial standards for size and performance providing a focus for large-scale mass production. Multilayer ceramic actuators do not have standards for production; business relationships and cooperative development in the supply change, so this diversity creates a more customer-based product. Furthermore, the economic crisis in major palladium producer Russia back in the 1990s drastically increased the market price of palladium, resulting in cost issues to manufacturers for using this metal electrode material [5] . Collectively, an effective strategy to decreasing the costs is to switch the widely used precious metal electrodes to base metal electrodes. Therefore, a reliable base metal co-firing technology would set up a solid foundation for the continually robust market growth in the future through further lowering the manufacturing costs. work on managing the lab affairs. Thanks to the Materials Chraracterization Laboratory (MCL) and Ke Wang for his assistance on TEM. The authors also want to thank PI Ceramics for providing the high-quality NKN ceramic powders.
doi:10.3390/act5010008 fatcat:uionrskq4vhrnoq6rcwzwnay3m