基于块材压电陶瓷的悬臂梁式压电微驱动器

Cantilever-Type Piezoelectric Micro-Actuator Based on the Bulk PZT

为了获得高性能、较低成本的压电微驱动器,设计了悬臂梁式压电微驱动器。利用压电性能优良的块材压电陶瓷（PZT）材料和硅（Si）基板通过共晶键合工艺接合,结合硅片切割、PZT减薄和激光烧蚀及硅的湿法刻蚀工艺完成了微驱动器的制备。对设计的悬臂梁式压电微驱动器的前端位移输出和共振频率进行了理论分析和仿真。工艺上以0.9μm厚的金（Au）层为中间层键合块材PZT和预制好沟槽的硅基板,利用物理研磨减薄的方法将块材PZT的厚度降至30μm左右,Si基板背面用湿法刻蚀的方法形成凹槽,随后利用准分子激光器对PZT层进行烧蚀加工至预制沟槽。制备的悬臂梁式微压电驱动器的大小为1 450μm×300μm×69.8μm。搭建测试系统测量确定了10 Hz交变频率、0-20 V电压下的尖端输出位移-电压曲线,并在电压峰峰值为0.2 V的条件下测得压电微驱动器的共振频率为18.43 kHz。悬臂梁式压电微驱动器所用的PZT材料压电性能高、均匀性好,器件尺寸小、位移输出大、频率响应快。该方法可用于批量制造微驱动器,以进一步降低成本。

In order to obtain a high-performance low-cost piezoelectric micro-actuator,a cantilever-type piezoelectric micro-actuator was designed.The bulk piezoelectric ceramics（PZT）with good piezoelectric performance and silicon substrate were jointed by the eutectic bonding process.The micro-actuator was fabricated by the combination of wafer dicing,PZT thinning,laser ablation and wet etching process for silicon.The theoretical analysis and simulation of the front-end displacement output and resonant frequency of the designed cantilever-type piezoelectric micro-actuator were made.The gold layer with the thickness of 0.9μm was used as the intermediate layer,and the bulk PZT and silicon substrate with the prefabricated groove were bonded by the gold layer.Then the thickness of the bulk PZT was reduced to about 30μm by physical grinding and thinning,and the back of the Si substrate was recessed by wet etching.Afterwards,an excimer laser was used to burn through the PZT layer to the prefabricated groove.The final size of the prepared cantilever-type piezoelectric micro-actuator was 1 450μm×300μm×69.8μm.The tip output displacement-voltage curves at 10 Hz alternating frequency under the voltage of0-20 V were measured by the built test system.Besides,the resonance frequency of the piezoelectric micro-actuator was 18.43 kHz measured at the peak-to-peak voltage of 0.2 V.The PZT materials used for the cantilever-type piezoelectric micro-actuator have high piezoelectric performance and good uniformity,and the prepared devices have small size,large displacement output and fast frequency response.The method can be used to manufacture micro-actuators in batches to further reduce costs.