An investigation of the piezoelectric properties of thick-film PZT actuators on ceramic substrates

摘要

Lead zirconate titanate (PZT) is a piezoelectric material that can sense or respond to mechanical deformations and can be used in ceramic electro-mechanical systems (C-MEMS). The microstructural, electrical and piezoelectric characteristics of thick PZT films on LTCC and alumina substrates were studied. The PZT composition was prepared with low-melting-point additives in order to decrease the sintering temperature and to be compatible with thick-film technology. The integration of the PZT thick-film materials on ceramic substrates could lead to degradation of the PZT's characteristics due to the interactions between an active PZT layer and a substrate, particularly with glassy LTCC material. To minimize the interactions with LTCC substrates an intermediate PZT barrier layer was integrated. The value of the piezoelectric coefficient d{sub}33 was found to be up to 120pC/N on an alumina substrate and approximately 50 on an LTCC substrate. Based on these results a cantilever-type actuator was designed and fabricated on alumina substrates. Under an applied voltage of 200 V the maximum tip deflection was about 5μm.