Research On Related Technologies And Application Of PZT

Along with the fast development, better and better market price of the Microelectromechanical system (MEMS), MEMS productions are required to be more reliable, economical and efficient;so, it puts forword more and more requirement for the capability of the material used in MEMS; at the some time, the precision and efficency of the micromachining methods is required to be batter and batter. PZT is one of the most useful functional materials, it is not only used as excellent driven material, also as sensitive transducer material. PZT also has potential application in the field of micro-electronics and photoelectron for its excellent ferroelectric capability. At present, more and more PZT preparation methods are developed, so more and more productions based on PZT are fabricated. But, there are also some problems that limit its application. For example, in the sol-gel preparation process, Pt bottom electrode has the problem of compatibility and fatigue properties, and the thermal annealing process is time-consuming; it is difficult to get PZT film more than 10um, also the micromachnining of PZT thick film is difficult.Aim at some problems of PZT preparation and micromachnining, the main research contents of the dissertation are:1. Fast preparation of high performance PZT film on ITO bottom electrode. ITO has high conductivity and high transparency in visible region of the Spectrum. First, high performance ITO thin film is prepared on SiO2 substrate by RF magnetron sputtering in Ar atmosphere, then, PZT thin film is prepared on ITO bottom electrode by sol-gel process and rapid thermal annealing. Finally the required PZT film has high dielectric and ferroelectric properties, and the fatigue property is improved.2. Design and fabrication of PZT thick film actuator used for valveless micropump.Micropump is one of the most important parts in micro fluid system. PZT drived actuator has the advantage of high resonance frequency, low actuation voltage, simple structure and good stability compared to other driving methods. In this research, PZT thick film that has piezoelectric constant d31 of about 260 pmV-1 and Young's modulus of about 60GPa is prepared by PZT-Si bonding and spray etching process. Then, PZT thick film actuator is designed and fabricated with large driving force and high resonance frequency. Finally the flow rate is measured.2. Ablation and micromachining of PZT thick film using Femtosecond laser.Fs laser micromachining which does not need mask is widely used for its unique technological advantages, such as true three dimentional fabrication ability, sub-micro resolution, low heat effect et al. For its ultrashort pulse duration and ultra high instantaneous power, it can ablate most materials with high precision. Based on the relationship of ablated crater size and applied laser fluence, the ablation threshold fluence of PZT ceramic is received. Finally, PZT thick film acruator is patterned using fs laser undering determinate laser parameters and feed rate.