三维激光加工的加工轨迹生成

根据三维激光加工离线自动编程的特点,提出了三维激光加工轨迹的生成算法。在计算机中,将连续的空间三维曲线,根据加工精度离散成许多节点点列,然后用直线顺序连接成折线,用空间折线逼近实际加工曲线。最后将离散的节点点列的计算机数据映射成实际激光加工机中激光头的位置和姿态数据,直接生成加工代码进行三维激光加工。     

新三维激光加工方法的研究

1 三维激光加工机的优点用于切割不锈钢或钢板等平板的普通二维激光加工机,可根据NC数据将其切割成任意形状,而无需采用模具.因此,这种加工机广泛地应用于板金加工行业.然而,对汽车面板等各种冲压成形产品,则不能用激光喷嘴固定在下方的二维激光加工机进行打孔加工或切割加工,这需用三维激光加工机,这种加工机除X、Y、Z三轴外,在加工台上装有自由垂直旋转激光喷嘴的轴(A轴)和水平旋转轴(C轴).     

超微细加工技术的动向

随着微细加工技术的发展,可制作直径为几千微米的齿轮之类的结构部件或者将其组合成亚毫米尺寸的执行元件以及传感器,并且正在实现将其系统化的微机械.要实现微机械,不仅需要传统的机械结构材料,而且需要Si之类的包括半导体材料     

基于飞秒激光的光纤三维微结构制备研究

为适应新型光纤传感器件的需要,进行了飞秒激光在石英光纤材料上制备三维微结构的工艺探讨。实验结果表明,光纤的烧蚀阈值约为1.5 J/cm2,烧蚀孔的深度与能量对数基本上符合线性关系。在一定条件下,适当的增加激光能量有利于改善微孔的垂直度。理论分析了锥孔和直孔的成形机理,探讨了微孔内壁形貌的形成机制和加工过程中光纤背面出现的崩碎现象。采用适当的加工工艺,试制了光纤F-P腔、光纤端部悬臂梁等三维微结构。     

微电子机械系统的进展与应用前景

本文论述了MEMS的研究进展、设计思想、主要加工技术及应用前景。     

三维微结构制作现状与进展

随着微机电系统(MEMS)的深入研究和快速发展,三维微细加工技术对于微机电的开发和生产具有非常重要的意义.详细介绍了现阶段三维微结构各种制作方法和工艺技术,分析了其原理和特点,比较了各种方法的优劣;讨论了三维微结构开发现状及有待解决的关键技术,综述了利用电子束曝光技术进行三维微结构制作的应用现状并指出了其发展前景.     

微机械臂激光驱动机理分析

对一种激光驱动的微臂机构的运动机理进行分析。该微机械臂的典型长度在亚毫米量级,宽度和厚度在数微米量级。微臂同一个半导体激光器单片集成或混合集成成为一个整体。当激光器输出光脉冲时,微臂将发生振动。文中采用一端固定、一端自由运动的长方形悬臂的力学模型,分析比较了激光的光压作用和激光的热效应两种机理。根据推导出的公式估算,得出了在现有条件下激光驱动的基本机理是光的热效应的结论。对这种微臂的运动特性作了初步的讨论。     

三维激光加工的轨迹规划的研究

在汽车覆盖件的激光加工中,一个覆盖件上的边界以及众多的大大小小的孔洞都可以用激光切割一次完成。如何使加工连续进行,一次完成一个覆盖件上的所有部分的切割工作以及合理安排加工轨迹的切割顺序是进行三维激光加工离线自动编程要解决的问题,它直接影响到汽车生产的生产效率。本文研究了三维激光加工激光头行走的特点,为了一次完成工件上所有孔、洞的切割工作,避免与工件发生碰撞,提出了激光头位姿在过渡轨迹和安全平面上的规划方法,同时利用神经网络方法和最短路径法对加工顺序进行合理安排,以提高加工效率。该方法用在作者开发的三维激光加工离线自动编程系统中,取得了满意的效果。     

微机械加工技术

微机械加工技术是发展微型固态集成传感器,微执行器和微机械构件的一种关键技术,它以硅作为基本材料,集合了精密腐蚀、薄膜生长、硅—绝缘体和硅—硅的键合技术、层间连接技术以及其它集成电路的典型工艺去制造各种三维以硅为基础的微机械和微型器件。本文重点介绍微机械加工的几种关键技术和我们的主要研究结果。     

MEMS技术的发展与应用

主要介绍了MEMS技术的背景、分类、应用、发展趋势。     

多孔硅及其在MEMS中的应用

具有不同孔径尺寸和孔隙率的多孔硅在不同的 MEMS中可作为功能结构层和牺牲层。简要介绍了多孔硅的结构和制备方法 ;与体微机械和表面微机械加工技术相比 ,多孔硅技术的优势被详细阐述 ;针对多孔硅材料的性质 ,讨论了多孔硅在不同领域的应用。     

Electro-thermal Stimuli for MEMS Testing in FSBM Technology

The development of low-cost go/no-go procedures for MEMS production testing is one of the main issues of MEMS manufacturability. In particular, the generation of low-cost test stimuli is a real challenge. In this paper, we investigate the generation of electrically-induced thermal stimuli to test electro-mechanical structures. Static, transient and harmonic responses are studied and it is demonstrated that they can be used for efficient detection and classification of several faulty devices.     

The HARPSS process for fabrication of precision MEMS inertial sensors

The high aspect-ratio combined poly- and single-crystal silicon micromachining technology (HARPSS) and its application to fabrication of precision MEMS inertial sensors are presented. HARPSS is a single wafer, all silicon, front-side release process which is capable of producing 10–100's of microns thick, electrically isolated, 3-D poly- and single-crystalline silicon microstructures with various size air-gaps ranging from sub-micron to tens of microns. High aspect-ratio (>50:1) polysilicon structures are created by refilling 100's of microns deep trenches with polysilicon deposited over a sacrificial oxide layer. This technology provides features required for precision micromachined inertial sensors. The all-silicon feature of this technology improves long term stability and temperature sensitivity while fabrication of large area, vertical electrodes with sub-micron gap spacing will increase the sensitivity by orders of magnitude.     

SOI MEMS陀螺的制造和测试

This paper presents an SOI（silicon on insulator） MEMS（micro-electro-mechanical systems） vibratory gyroscope that was fabricated using bulk micromachining processes.In the gyroscope architecture,a frame structure that nests the proof mass is used to decouple the drive motion and sense motion.This approach ensures that the drive motion is well aligned with the designed drive axis,and minimizes the actual drive motion component along the sense detection axis.The thickness of the structural layer of the device is 100μm,which induces a high elastic stiffness in the thickness direction,so it can suppress the high-order out-of-plane resonant modes to reduce deviation.In addition,the dynamics of the gyroscope indicate that higher driving mass brings about higher sensing displacements.The thick structural layer can improve the output of the device by offering a sufficient mass weight and large sensing capacitance.The preliminary test results of the vacuum packaged device under atmospheric pressure will be provided.The scale factor is 1.316×10^-4 V/（deg/s）,the scale factor nonlinearity and asymmetry are 1.87%and 0.36%,the zero-rate offset is 7.74×10^-4 V,and the zero-rate stability is 404 deg/h,respectively.     

步进跟踪模式下的单脉中雷达三维成像技术研究

该文提出了步进跟踪模式下的单脉冲三维成像方法。分析了步进跟踪体制下差信号的幅度线性调制问题,同时提出了补偿方法,该方法解决了单脉冲三维成像中所必须的目标精确跟踪问题,最后通过仿真验证了所提方法的有效性。     

Investigation of RF sputtered PSG films for MEMS and semiconductor devices

In this work, we report the preparation of phospho-silicate-glass (PSG) films using RF magnetron sputtering process and its application as a sacrificial layer in surface micromachining technology. For this purpose, a 76 mm diameter target of phosphorus-doped silicon dioxide was prepared by conventional solid-state reaction route using P₂O₅ and SiO₂ powders. The PSG films were deposited in a RF (13.56 MHz) magnetron sputtering system at 200-300 W RF power, 10-20 mTorr pressure and 45 mm target-to-substrate spacing without external substrate heating. To confirm the presence of phosphorus in the deposited films, hot-probe test and sheet resistance measurements were performed on silicon wafers following deposition of PSG film and a drive-in step. As a final confirmatory test, a p-n diode was fabricated in a p-type Si wafer using the deposited film as a source of phosphorus diffusion. The phosphorus concentration in the target and the deposited film were analyzed using energy dispersive X-rays (EDAX) tool. The etch rate of the PSG film in buffered HF was measured to be about 30 times higher as compared to that of thermally grown SiO₂ films. The application of RF sputtered PSG film as sacrificial layer in surface micromachining technology has been explored. To demonstrate the compatibility with MEMS process, micro-cantilevers and micro-bridges of silicon nitride were fabricated using RF sputtered PSG as a sacrificial layer in surface micromachining. It is envisaged that the lower deposition temperature in RF sputtering (<150 °C) compared to CVD process for PSG film preparation is advantageous, particularly for making MEMS on temperature sensitive substrates.     

宽范围可调MEMS集成滤波器的设计与制作

基于MEMS平面螺旋电感和MEMS可调平行板电容设计并制作了一种宽可调范围的集成可调带通滤波器。理论分析并计算了可调滤波器电感和可调电容的取值范围,利用HFSS设计得到各元件结构参数,并使用AnsoftDesigner分析软件对可调滤波器电路进行了模拟仿真。设计得到的可调滤波器中心频率调节范围为400～700MHz,可调率达75%,实现了宽范围可调,3dB相对带宽范围为5%～10%,插入损耗小于5dB,芯片尺寸为20mm×6mm×0.4mm。给出了一套基于MEMS平面工艺的MEMS集成可调滤波器的制作流程,实现了MEMS集成可调滤波器的工艺制作及测试。测试结果表明,获得的可调滤波器实现了通带频率宽范围可调。     

GPU-ACCELERATED FEM SOLVER FOR THREE DIMENSIONAL ELECTROMAGNETIC ANALYSIS

A new Graphics Processing Unit (GPU) parallelization strategy is proposed to accelerate sparse finite element computation for three dimensional electromagnetic analysis.The parallelization strategy is ...