共晶键合与减薄技术的压电能量采集器（英）

采用微硅 锆钛酸铅（Si-PZT）悬臂梁结构并在悬臂梁末端附加镍质量块,构成可以工作于低频环境（小于1 000 Hz）的微压电能量采集器,一种利用压电效应将环境振动能转换为电能的器件。利用金薄膜作为中间层的共晶键合技术和PZT研磨减薄技术制备了微压电悬臂梁结构,PZT减薄实验最好结果为减薄至8 m。镍质量块（2 mm2 mm0.6 mm）采用微电铸工艺制备。通过对硅片与块材PZT的共晶键合工艺与PZT减薄技术的研究,制备出总厚度约为71 m的Si-PZT悬臂梁结构,其中硅梁厚约为47 m,PZT梁厚约为24 m。制备的微压电振动能量采集器样品的测试结果表明:在谐振频率为950 Hz,1.0g加速度激励条件下,其交流输出峰值电压可达958 mV。     

基于激光毛化技术的5052铝合金粘接试验研究

为了提高5052铝合金的粘接性能,利用脉冲光纤激光的短脉冲和高峰值功率的特性,对铝合金试件进行了激光毛化试验研究。通过正交实验法,研究了平均功率、扫描速度、脉冲频率和脉冲宽度等工艺参数对激光毛化质量的影响,以及各工艺参数的影响权重,并求得最佳工艺参数,最佳工艺参数为平均功率90 W、扫描速度10 mm/s、脉冲频率1000 kHz、脉冲宽度200 ns。根据优化后的工艺参数,加工获得了粗糙度2.35 μm,然后对激光毛化后的铝合金试件进行单搭接拉伸试验,研究发现粘接强度随着粗糙度的增大而增大,当粗糙度到达一定程度时,粘接强度反而会随着粗糙度的增大而减小。另外,粘接强度还跟铝合金表面的微织构的类型及疏密程度都有很大关系。     

Spectral and modulation properties of a largely tunable MEMS-VCSEL in view of gas phase spectroscopy applications

An extensive characterization of the spectral properties of a largely tunable laser in the 1.56-μm spectral range is reported. This device combines a vertical-cavity surface-emitting laser (VCSEL) with a micro-machined (MEMS) Bragg mirror in a very compact arrangement. The large tunability obtained by an electro-thermal actuation of the MEMS mirror makes this device very attractive for high-resolution spectroscopy. Relevant laser parameters for the implementation of wavelength modulation spectroscopy techniques in gas sensing, such as tuning and modulation properties, are presented. A preliminary gas spectroscopy experiment performed with this laser is also shown.     

All polymer asymmetric Mach-Zehnder interferometer waveguide sensor by imprinting bonding and laser polishing

We present an all polymer asymmetric Mach–Zehnder interferometer(AMZI) waveguide sensor based on imprinting bonding and laser polishing method. The fabrication methods are compatible with high accuracy waveguide sensing structure. The rectangle waveguide structure of this sensor has three sensing surfaces contacting the test media, and its sensing accuracy can be increased 5 times compared with that of one surface sensing structure. An AMZI device structure is designed. The single mode condition, the length of the sensing arm, and the length deviation between the sensing arm and the reference arm are optimized. The length deviation is optimized to be 19.8 μm in a refractive index range between1.470 and 1.545. We fabricate the AMZI waveguide by lithography and wet etching method. The imprinting bonding and laser polishing method is proposed and investigated. The insertion loss is between-80.36 dB and-10.63 dB. The average and linear sensitivity are 768.1 d B/RIU and 548.95 dB/RIU, respectively. And the average and linear detection resolution of the sensor are 1.30×10~(-6) RIU(RIU: refractive index unit) and 1.82×10~(-5) RIU, respectively. This sensor has a fast and cost-effective fabrication process which can be used in the cases of requiring portability and disposability.     

Thin layer laser bonding using spin-on-glass materials

We developed and characterized a new laser bonding process with a nano adhesive layer for transparent materials. The adhesive is spin-coated on a glass substrate and cured locally with a focused laser beam. The minimum viscosity of the adhesive is very low, so that a thin layer only a few hundred nanometers thick can be coated on a cover substrate. Laser irradiation from a Nd:YAG laser system with a wavelength of 1064 nm is employed as the curing source for the localized nano layer bonding process. The measured thickness of the bonding layer is in the range of 400 nm to 3 μm. This process can be applied to the nano or micro bonding of various transparent systems such as flat panel displays, biochips, and heat-sensitive microelectronics. We present experimental results and discuss the process characteristics.     

高功率二极管激光器封装的多层焊接技术

 对高功率二极管封装工艺中的焊接技术进行了研究，掌握了高真空下利用蒸发沉积制备铟（In）焊料的方法，在不加助焊剂的情况下进行了多层焊接实验，并对封装的连续、准连续激光器进行了性能检测。结果表明，利用In和In-Sn合金的多层焊接技术进行激光器封装的方法是切实可行的。     

大口径氘化磷酸二氢钾晶体离线亚纳秒激光预处理技术

大口径氘化磷酸二氢钾(DKDP)晶体抗激光损伤性能偏低严重地制约着大型高功率激光装置输出水平.本研究利用离线亚纳秒激光预处理技术有效地提升了大口径DKDP晶体抗激光损伤性能.实际使用情况表明,采用离线亚纳秒激光预处理后,DKDP晶体在9 J/cm²激光通量辐照下的表面平均损伤密度得到大幅下降,由未处理前的5.02 pp/cm²(1pp表示1个百分点)降至0.55 pp/cm²,降幅为一个数量级.同时,激光预处理对晶体损伤尺寸具有一定的抑制作用,预处理后晶体损伤点尺寸分布曲线向尺寸减小的方向平移,尺寸分布峰值由预处理前的25μm降至预处理后的18—20μm.     

电磁驱动大尺寸MEMS扫描镜的研究

基于微机电系统工艺,设计并制作了一种电磁驱动大尺寸的二维扫描振镜.分析了两种不同的电磁驱动方式产生的力的大小,选择驱动力较大的双极子方式作为驱动.运用有限元法模拟了器件的谐振频率静态及动态响应,仿真结果与实际测得的结果一致.描述了振镜的工艺流程及封装方式,并制备了振镜.实验测得振镜在120mA静态电流驱动下,慢轴和快轴分别能达到的最大转角为±4.5°及±5°,慢轴及快轴的谐振频率分别为348Hz及660Hz,并得到在此谐振频率下的李萨如图形.将器件用于激光成像系统之中,使得散斑对比度下降到4.2%,激光成像质量得到很大提升.     

Laser-induced damage in InSb at 1.06 μm wavelength—a comparative study with Ge, Si and GaAs

This paper deals with the study of laser-induced damage in n-type single crystal InSb irradiated with a Nd: glass laser of 1.06 μm wavelength and 300 μs pulse duration. Samples of different surface quality were prepared by mechanical lapping and polishing by diamond paste. Evolution of damage morphological features observed at different power densities is discussed. Damage threshold results are analysed in terms of a thermal model taking into account the temperature dependence of various physical parameters and using the finite difference method of calculation. A comparative study of laser induced damage in InSb, Ge, Si and GaAs irradiated under similar conditions is also presented.     

基于法布里-珀罗微腔阵列的光读出红外热成像器件设计与制作

提出了一种新颖的基于硅基法布里珀罗微腔阵列的光读出红外热成像器件 ,该器件利用光学读出技术将红外图像直接转化为可见光图像 ,其焦平面阵列 (FPA)是一个基于微机电系统 (MEMS)制作的法布里珀罗微腔阵列。阐明了器件的工作原理 ;完成了可动微镜结构、热机械、可见光读出部分设计。理论分析表明 ,对Al/SiO2 双材料体系而言 ,SiO2 厚度应大于 0 .3μm ,其最佳厚度比为 0 .5 98,相应的最大热 机械灵敏度可达 10 -8m/K。采用体硅微机电系统技术 ,实验制作出了 5 0× 5 0焦平面阵列。     

分子整流器整流特性的键桥调控效应

利用密度泛函理论和非平衡格林函数方法,研究了基于同一分子在不同空间构型下形成的三个不同分子器件的电子输运特性及整流效果. 研究表明:旋转中间苯环(键桥——π桥),能明显改变整流效果,这是因为改变了分子轨道的离域性,这一发现说明通过改变键桥的空间取向能有效地调控分子整流器的整流性质,这对于设计新型分子整流器有重要意义. 关键词： 分子整流器 键桥 密度泛函理论 非平衡格林函数     

热键合技术及其在激光方面的应用

由于热键合技术具有适用范围广、对材料物化性能基本无影响等优点 ,所以它在激光方面有着越来越广泛的应用 ,尤其是在高功率激光和小型激光系统中的应用更为广泛。简单介绍了热键合技术的发展现状 ,并对其基本原理进行了详细的阐述。重点介绍了该技术在激光方面的用途和前景。由于热键合技术对工艺水平的要求较高 ,研究难度较大 ,探索性较强 ,所以加快它的研究和发展 ,对我国激光事业的发展有着十分重要的作用     

基于微机电系统光栅平动式光调制器实验和优化设计

基于微机电系统(MEMS)的光栅平动式光调制器(光栅平动式光调制器)调制性能的实验研究关系到其进一步应用。设计了光栅平动式光调制器的相干光学信息处理系统实验方案,He-Ne激光器出射的光束经扩束器和准直透射后成为平行光入射光栅平动式光调制器,被测光栅平动式光调制器放置在相干光学信息处理系统的输入面,滤波器在频谱面上,显微镜放大像面上的信号,经CCD在计算机上记录存储;实验结果和理论分析吻合。对光栅平动式光调制器进行方案优化,将可动光栅边框和悬臂梁表面处理成不反光,使可动光栅和下反射镜构成的整个反射面为光栅周期的整数倍。经理论计算,在光栅周期为8μm,光栅占空比为0.5,光栅边距为2μm,周期数为6的条件下,光栅平动式光调制器图像填充率为74.67%,光学效率为81.06%,衬比度大于5000∶1。     

激光扫描阵列结构增强不锈钢与塑料的连接强度

本文采用光纤激光器在不锈钢表面上制备圆形阵列结构来增强不锈钢与塑料的连接强度。研究了激光制备的圆形阵列结构参数以及连接参数对不锈钢与塑料连接强度的影响。结果表明,不锈钢表面经过激光扫描构形处理后能显著提高不锈钢与塑料的连接强度,在压力作用下,熔融塑料渗入激光构造微孔形成的机械互锁是增强不锈钢与塑料连接强度的主要机制。激光构形后不锈钢表面上的毛刺高度、数量以及覆盖率对连接接头的连接强度有重要影响。毛刺高度为10~20μm,毛刺数量占比Tm小于14.82%时,不锈钢与塑料在连接面处断裂,剪切力随着Tm的增加而增加;当Tm值高于14.82%时,在塑料处断裂,且剪切力数值在塑料的平均拉伸断裂力(950 N)上下浮动。不锈钢与塑料连接接头断裂于塑料处时所对应的最小覆盖率为38.5%,此时剪切力为900 N。此外,激光扫描处理过程中不锈钢与塑料连接的温度与压力对连接强度有重要影响,在加热温度为400℃时,不锈钢与塑料连接接头的剪切力最强;当压力为75 kN时,不锈钢与塑料连接接头的剪切力最强。     

热超声键合换能系统动力学特性的非线性检验

根据实际超声换能系统的振动测试，提出了热超声键合换能系统动力学特性的非线性检验方法，利用基于相空间重构的替代数据法，通过对换能杆末端的实测数据进行正确替代，并用非线性动力学的理论来检验其是否具有非线性.通过实验对超声换能杆末端轴向、俯仰、横向的振动时间序列的关联维数进行了准确的计算，从而清晰地描述了上述三个方向的动力学特性.所提出的方法有利于更好地认识超声键合换能系统，为建立更加合理的非线性动力学模型奠定良好的理论基础，有很好的应用价值. 关键词： 超声键合 时间序列 相位随机化 替代数据     

Laser Micromilling Technology as a Key for Rapid Ceramic MEMS Devices

The flexible laser micromilling technology for ceramic MEMS production of microhotplates in the surface mount device (SMD) package is described. Current results demonstrate that using described technology makes it possible to manufacture all parts of MEMS sensor in the SMD with form factor of SOT-23 package type.     

Determination of the material properties of microstructures by laser based ultrasound

In most applications of MEMS the mechanical properties of the used materials are key parameters for the perfect working of the microsystems. Measuring bulk acoustic waves excited in MEMS structures with ultra-short laser pulses is a powerful method for the accurate and non-destructive evaluation as well as for the characterization of material properties. The pump-probe laser-based acoustic method generates bulk acoustic waves in a thermo-elastic way by absorbing the pump laser pulses. The acoustic waves are partly reflected at any discontinuity of the acoustic impedance. At the surface of the specimen the reflected acoustic pulses cause changes of the optical reflection coefficient, which are measured with the probe laser pulses. Thin membranes are part of numerous microelectromechanical systems (MEMS) like sensors, activators and bulk acoustic wave (BAW) filters for example. The described non-destructive and non-contact method is the right approach for testing such thin and brittle structures like membranes. Results of measurements on freestanding aluminium-silicon nitride multi-layer membranes with total thicknesses in the order of several hundred nanometers are presented and compared with thermo-elastic models and with measurements of the supported case. The measured results are used for the determination of the moduli of the membranes.     

Electric feed-through for vacuum package using double-side anodic bonding of silicon-on-insulator wafer

It is not easy to hermetically seal using anodic bonding on both sides of silicon-on-insulator (SOI) wafer. Taking this into consideration, we suggest an electrical feed-through method for anodic bonding on the both sides of SOI wafer. The suggested method is illustrated on the basis of vacuum package of a conventional two-dimensional (2-D) micro-scanner. Electric feed-through for anodic bonding and electrical interconnection through the glass/silicon interface to the 2-D micro-scanner in the package are presented. The proposed electrical feed-through method is investigated by characterizing bonding current. The bonding current characteristics show that the electric feed-through has formed electric field distribution required for double-side anodic bonding. The operation characteristics of packaged 2-D micro-scanner are also investigated, which show successfully performed electric interconnection between inside and outside of the package. The proposed method is an effective technique for double-side anodic bonding based package not only for micro-scanner but also for different mechanical oscillators such as accelerometer, gyroscope and etc.     

激光对电荷耦合器件硬破坏机理研究

就激光对组成ＭＯＳ结构电荷耦合器件材料和整个器件的产生硬破坏的过程进行了理论和实验研究。提出激光的热作用和等离子体冲击波的机械作用是导致电荷耦合器件结构被破坏的主要原因。得到了ＹＡＧ激光致使组成电荷耦合器件的半导体材料的光学击穿阈值、视见损伤阈值、热熔融阈值和致使整个器件失效的激光功率阈值等有关结果。 关键词：     

微结构特性的光学测试平台

微结构是微机电系统的基本元件,其几何尺寸、运动特性、材料及力学特性直接影响微机电系统的整体性能。提出一种将计算机微视觉、米劳显微干涉、频闪成像和激光多普勒测振等技术充分融合的微结构静态和动态特性的光学测试平台,分别对微谐振器的平面和离面周期运动特性和微机械扭转镜的离面瞬时运动特性进行测试研究。实验结果表明,利用计算机微视觉和频闪成像技术能够实观微结构的平面位移、运动相位及喈振频率等周期运动参量的测试．位移的重复精度为30nm;利用显微干涉和频闪成像技术可实现微结构的离面位移及表面扭曲等周期运动参量的测试．位移的重复精度为3nm;激光多普勒测振技术具有在频域上对微结构瞬态运动进行分析的优点．是时域上周期运动测试的重要补充。