PCB镀通孔疲劳寿命对设计参数的灵敏度分析

在PCB镀通孔疲劳寿命评估IPC模型的改进模型基础上,分析了镀通孔疲劳寿命对基板厚度与孔径之比(即厚径比l/r0)、基板厚度与镀层厚度之比(l/t)以及基板作用半径与孔半径之比(R/r0)的灵敏度。结果表明,镀通孔疲劳寿命对(l/r0)的灵敏度随(l/t)增大而减小;对(l/t)的灵敏度随(l/r0)增大而减小;而对(R/r0)的灵敏度则随(l/r0)增大而增大、随(l/t)增大而减小。最后,利用IPC的试验研究结果数据进行了验证。     

一种新型微结构高灵敏度光纤温度传感器

为实现高精度温度检测,提出一种基于飞秒激光微加工的新型光纤温度传感器的制备方法。利用波长为780nm的飞秒激光脉冲在刻写有光纤布拉格光栅(FBG)的单模光纤(SMF)包层上加工槽状微结构,通过磁控溅射的方法在其表面沉积温敏薄膜,从而制备一种光纤温度传感探头。理论分析了环状微结构镀膜实现温度增敏的工作机制,通过温度实验讨论了不同微结构镀膜对温度增敏效果的影响。实验结果表明,在FBG包层上单纯加工槽状微结构(无镀膜),对温度的灵敏度影响不大,基本上不改变光栅中心波长随温度变化的趋势;加工槽状微结构后再沉积敏感薄膜,可明显提升传感器的温度灵敏度,其中环状膜层较镀膜螺纹膜层微结构的增敏效果更加明显,其灵敏度可达21.37pm/℃。     

热电薄膜型微传感器的优化设计

详细分析了一维热电薄膜型微传感器的优化设计模型 ,探讨了热阻、灵敏度和探测率与传感器几何尺寸之间的关系。分析的时候考虑到热电堆的热端与敏感面的距离 m对传感器性能的影响。经过分析得出 :当 m(热电堆到热敏感面距离 )为定值时 ,灵敏度 S随梁长 l增大而增大 ,探测率 D*随着 l的增大先增大后减小 ;当 l为定值时 ,S和 D* 均随 m增大而减小。用曲线形式所表示的分析结果为此类传感器的优化设计提供了依据。     

基于微管腔的光纤激光盐度传感研究

基于光学无源方案的光纤盐度传感器中光与物质的相互作用长度受限,且通常需要 单独的流体通道设计,增加了检测复杂度,为此提出了一种基于薄壁微管腔和环腔结构的 光纤激光盐度传感器。将薄壁微管腔作为盐度敏感单元和光滤波器,与掺铒光纤相接构成 光纤环形谐振腔。通过拉锥光纤耦合在薄壁微管腔激发出回音壁谐振模,其中心波长与盐 度线性对应,实现薄壁微管腔内溶液盐度的传感测量。与无增益的微管腔透射谱相比,激 光可以提供具有更高信噪比和更窄线宽的传感信号。实验结果表明,在0‰—45‰盐度范围 内,提出的光纤激光盐度传感器的传 感灵敏度为36.5 pm/‰,线性 度达到0.999,盐度测 量误差小于±0.751‰,最小探测极限为0.485‰,且不需要额外的流体测量通道,有望成为海洋盐度探测的 有力工具。     

一种双包层半径光纤布拉格光栅传感器

光纤布拉格光栅已经成为非常有前景的温度、应力及其它参数测量的传感元件,但其存在温度和应力的交叉敏感问题.提出了一种双包层半径光纤布拉格光栅传感器,将一个布拉格光纤光栅分成两半,各自具有不同的包层半径,其中一半保持不变,另一半包层半径从62.5m减小到40m.实验结果表明,两半光纤布拉格光栅的温度灵敏度均为10.4 pm/℃,而应力灵敏度分别为1.12 pm/ue 和3.89 pm/ue.初始的单个布拉格反射峰分裂成两个,分别对温度和应力敏感,而两个反射峰之间的波长差只受应力的影响,随着应力的增加其波长差逐渐增加.因此,通过这一个光纤布拉格光栅即可分辨出温度和应力所引起的布拉格波长漂移.该光纤光栅传感器结构简单、体积小巧、成本低廉、制作方便,可以广泛应用在各个领域实现温度和应力的同时测量.     

测量多种气体体积分数的PCF传感器结构

为提高气体体积分数传感器的灵敏度、抑制光纤的模间干扰,设计了双通道边孔型结构,利用COMSOL软件建立气体体积分数传感模型的方法和损耗谱分析法,研究不同结构参数和镀膜厚度对光纤气敏特性的影响,进行理论分析和实验验证,调整薄膜材料厚度和光纤气孔尺寸,通过分析光纤双折射变化规律得到最优的各类参数方案。结果表明,该传感器对氢气的探测灵敏度为0.36 nm/%,对甲烷的探测灵敏度为2.89 nm/%,且线性度高。该光子晶体光纤气体传感器具有灵敏度高、响应速度快等优点,还能同时对两种气体进行检测,应用范围广,为研发实际生活及工业领域相关气敏性薄膜和实现一根光纤传感器同时检测3种甚至更多种气体体积分数提供了参考思路。     

基于表面等离子体共振的椭圆侧芯光子晶体光纤传感器研究

设计出一种高灵敏度的新型椭圆侧芯光子晶体光纤传感器模型。圆形孔和3种不同大小椭圆孔构成该椭圆侧芯光子晶体光纤空气孔，其中椭圆孔的椭圆率分别为e、e1、e2，在椭圆率为e的左侧椭圆孔内涂敷金纳米薄膜。通过有限元分析软件COMSOL对传感器的传感特性进行数值分析。研究发现：表面等离子体共振的共振峰对待测液体折射率的变化有很高的传感灵敏度；光子晶体光纤传感器的灵敏度会随着椭圆率e、e1以及金纳米薄膜的厚度而变化。折射率在1.40～1.42范围内，传感器灵敏度随着e1的增大而增大；折射率在1.42～1.43范围内，传感器灵敏度随着e1的增大先减小再增大。当椭圆率e1=1.2、折射率为1.43时，灵敏度高达31800 nm/RIU（折射率单元）。折射率在1.38～1.43范围内，传感器灵敏度随着椭圆率e的增大而增大，当椭圆率e=2.3时，灵敏度高达33200 nm/RIU。折射率在1.42～1.43范围内，传感器灵敏度随着金纳米薄膜厚度的增大而减小，在折射率为1.43、金纳米薄膜厚度为40 nm时，传感器灵敏度高达34600 nm/RIU。     

镀膜双峰谐振长周期光纤光栅折射率传感的优化设计与实验

利用镀自组装薄膜的双峰谐振长周期光纤光栅(LPFG)实现了高灵敏的折射率传感,给出了提高镀膜双峰谐振光纤光栅对环境折射率(SRI)灵敏度的途径。确定最佳镀膜厚度,使光纤包层模位于模式转换区附近;调整光纤半径,使镀膜后光栅的双峰位于相位匹配转折点(PMTP)附近,给出了确定最优膜厚和光纤半径的方法。将不同半径的双峰光栅镀自组装聚丙烯胺盐酸盐(PAH)/聚丙烯酸(PAA)薄膜后,放入不同浓度的葡萄糖溶液中进行折射率传感实验。结果表明:通过优化光纤半径和薄膜厚度,镀膜后工作于模式转换区附近和PMTP附近的双峰光栅对1.333~1.372范围内折射率的灵敏度高达3985nm/RIU(RIU为单位折射率),明显高于不在模式转换区或PMTP附近的光栅,亦高于已报道的非双峰镀膜长周期光纤光栅。     

基于涂覆Pd/WO3膜的长周期光纤光栅氢气传感器设计

氢气浓度的高精度、快速监测在众多领域具有重 要意义。本文提出一种基于涂覆Pd/WO₃膜的长周期光纤光栅氢气浓度传感器。首先研究了 镀Pd/WO₃膜的LPFG对氢气的传感特性,利用光学仿真软件模拟了薄膜折射率在1. 99范围内的传感情况,仿真结果表明当氢气浓 度增加时,Pd/WO₃薄膜折射率降低,LPFG透射谱谐振波长蓝移,谐振波长偏移对Pd/WO₃薄膜 折射率变化的灵敏度为256.9 nm/RIU。为了增强镀膜LPFG氢气传感器 的灵敏度,进一步研究 了包层半径及周期对其谐振波长灵敏度的影响,结果表明LPFG的谐振波长灵敏度随周期Λ的 增大而增加;在相同周期的条件下,包层半径越小,谐振波长的偏移值越大,该研究对开发 高灵敏度可复用的光纤氢气传感器具有重要指导意义。     

环形腔微光纤MZI的海水温/盐度同时测量的设计与模拟

为实现海水中温度和盐度(温/盐度)同时测量,设 计了一种环形腔微光纤Mach-Zehnder干涉仪(MZI)。首先,计算了MZI在不同温/盐度下的 输出光谱,光谱中同时存在谐 振峰和干涉峰,分别由环形腔谐振和MZ干涉引起,由于谐振峰和干涉峰对温/盐度变化的响 应不同,因而 可将其运用于海水的温/盐度同时测量;其次,为了提升MZI的测量灵敏度,计算了灵敏度 与 其结构参数的关系。结果表明,谐振峰的温/盐度灵敏度只与制成环形腔的微光纤直径有关 ,而干涉峰灵敏 度同时与MZI两个微光纤臂的直径和长度相关,当制成环形腔的微光纤臂是MZI两臂中直径 较 小且长度较大的一臂时,能得到较高的测量灵敏度。经过优化后,干涉峰的温/盐度灵 敏度比传统的 光纤光栅分别提升了75倍和约3650倍。本文 设计的MZI具有结构简单、灵敏度高的优点,可为研制新型的海洋微光纤传感器提供参考。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.