【作者】 孙健；

【导师】 李以贵；

【作者基本信息】 上海交通大学 ， 微电子学与固体电子学， 2011， 硕士

【摘要】 近年来,随着微电子技术、微机械加工技术以及无线传感技术的突飞猛进,诸如嵌入式系统、射频识别系统、无线传感器以及各种可植入微型传感器之类的电子产品已经进入集成化、微型化和低功耗的时代,传统的输电线路和化学电池已经不能满足这些微型电子器件的供能要求。基于MEMS技术的振动能量采集器利用压电材料的压电效应,将周围环境中的振动机械能转化为电能,它可以很好的与各种微电子芯片、微传感器和微执行器集成在一起,为微型电子器件提供持久、稳定和清洁的能源。目前,MEMS压电振动能量采集器已经成为国内外许多研究小组的研究热点,并具有十分重要的科学意义和广阔的应用前景。本文围绕基于共晶键合技术的微压电振动能量采集器展开研究,概括了微型压电振动能量采集器的国内外发展现状与趋势,对各种结构的能量采集器进行了分析比较,提出了利用高性能块材PZT和硅片的共晶键合工艺制作高性能微型压电振动能量采集器,这是对高性能微能源设计和制造的一次有益探索,为下一步完善和优化微型压电振动能量采集器提供了很好的理论和实践基础。论文的主要研究内容是:在查阅了大量的中英文文献资料的基础上,探讨能量采集技术的研究背景及意义,系统分析了国内外关于MEMS压电振动能量采集器的研究进展;详细介绍了压电效应的原理和压电材料的分类,深入分析微型压电振动能量采集器的相关理论,推导压电悬臂梁的固有频率及电压、功率输出公式,并探讨悬臂梁的输出与其结构参数和施加加速度之间的关系;使用ANSYS有限元仿真软件对这种压电复合结构进行静态、模态和压电谐响应分析,针对使用环境中振动源频率普遍低于1000Hz的情况,确定其最佳结构尺寸以获得较低的固有频率;着重进行块材PZT与硅片的共晶键合工艺研究,获得了较好的键合结果,即在500℃下键合1h,键合强度可达13.2MPa;采用其他MEMS标准工艺制作微压电振动能量采集器样品,顺利完成了压电悬臂梁的工艺设计和实验,成功地制作出微型压电悬臂梁;搭建了一套完整的测试系统,包括信号发生器、功率放大器、示波器、振动台和加速度仪等,对制作的微压电振动能量采集器样品进行一系列性能测试,测试结果与仿真分析有较好的吻合。所制备的微能量采集器样品的谐振频率为815Hz,在0.5g加速度激励下,峰值输出电压可达632mV;最后,提出进一步改进器件成品率和器件性能的方案。更多还原

【Abstract】 In recent years, as the rapid development of IC technology, MEMS technology and wireless sensing technology, many electronic products, such as the embedded system, the RF recognition system, wireless sensors as well as other implanted micro-sensors, have entered a new era which is characterized as integration,miniaturization and low power consumption. Therefore, the traditional immovable transmission line and chemical batteries with limited lifespan cannot meet the energy requirements of these electronic micro-devices. The vibration energy harvester based on MEMS technology, which can be well integrated with many micro-electronic chips, micro-sensors and micro-actuators, can convert the omnipresent vibration energy into electric energy by means of piezoelectric effect of piezoelectric materials, thus supply the electronic micro-devices with lasting, stable and clean electric energy. At present, the MEMS piezoelectric energy harvester which is of great scientific significance and has broad application areas has become the research hotspot of many research groups at home and abroad.In this thesis, MEMS piezoelectric energy harvester based on eutectic bonding technology is studied; the present status and trend of development is illustrated. Through analysis and comparison of different types of energy harvester, MEMS piezoelectric energy harvester based on eutectic bonding of bulk PZT with high piezoelectric properties to Si wafer is proposed. It is a beneficial explorer of design and fabrication of micro energy resources and makes a good theoretical and experimental basis of further improvement of micro piezoelectric energy harvester.The main contents of the thesis are: firstly, the research background and significance of energy harvesting technology is investigated on the basis of reading many Chinese and English papers and information, and the domestic and abroad research development of MEMS piezoelectric energy harvester is listed systemically. Then the principle of piezoelectric effect and classification of piezoelectric materials is introduced. Deeply analyze the theory related to micro piezoelectric energy harvester and derivate the expressions of resonant frequency, output voltage and power of piezoelectric cantilever. The relationship between output and structural parameters and applied acceleration is also discussed. The resonant frequency, output of voltage and power of the piezoelectric cantilever theoretically are analyzed. Given the situation that the frequency of common vibration resources in the operating environment is always below 1000Hz, static analysis, model analysis and harmonic analysis of the piezoelectric cantilever is performed using the finite element software—ANSYS to determine the optimal structure size. The technology of eutectic bonding of bulk PZT to Si is investigated, and the sample of MEMS piezoelectric energy harvester is fabricated using other standard MEMS technologies. The performance is tested with a test system containing a waveform generator, an amplifier, a vibrator, an oscilloscope and an acceleration monitor. The test result is close to the calculation. Other feasible suggestions of advancing the performance of the device are also discussed at the end of the paper.Eutectic bonding of bulk PZT ceramics to Si wafers using Au thin film as an intermediate layer was investigated. A bond strength of more than 13MPa was attained at bonding temperature of 500℃and the bonding time is about 1h. Testing of the samples demonstrate that the resonant frequency is 815 Hz and the AC output voltage is around 632 mV at the acceleration of 0.5g.更多还原