双应力步降加速退化试验优化设计Monte-Carlo仿真

针对高可靠长寿命产品在双应力退化试验中存在的时间长、费用高、效率低的问题,提出了一种基于Monte-Carlo仿真的双应力步降加速退化试验优化设计方法。采用Monte-Carlo对加速试验进行仿真模拟,以监测频率、样本量大小、监测次数作为设计变量,以总的试验费用作为约束条件,以正常使用应力下的p阶分位寿命渐近方差估计作为目标函数,建立了基于Monte-Carlo仿真的双应力步降加速退化试验优化设计模型。通过仿真实例验证了该方法的有效性、可行性,为电子装备寿命预测的加速试验方案优化设计提供了理论支撑。     

竞争失效产品加速寿命试验优化设计Monte-Carlo仿真

针对竞争失效产品加速寿命试验存在试验时间长、费用高、效率低的问题,提出了一种基于Monte-Carlo仿真的竞争失效产品加速寿命试验优化设计方法。采用Monte-Carlo对竞争失效产品的加速寿命试验进行仿真模拟,以正常使用应力下的p阶分位寿命渐近方差估计最小为目标,以各试验应力水平及对应应力下的试验截尾数作为设计变量,采用MLE理论进行统计分析,建立了基于仿真的竞争失效产品加速寿命试验优化设计模型。最后通过GA-BP神经网络对目标函数进行拟合,降低了仿真规模,提高了试验效率,为电子装备寿命预测的加速试验方案优化设计提供技术支撑。     

步降加速寿命试验优化设计Monte-Carlo仿真

针对加速寿命试验存在试验时间长、费用高、效率低的问题,提出了一种基于Monte-Carlo仿真的步降加速寿命试验优化设计方法。采用Monte-Carlo对步降加速寿命试验进行仿真模拟,以正常使用应力下的p阶分位寿命渐近方差估计和各应力水平下的特征寿命之和最小为目标,以各试验应力水平及对应应力下的试验截尾数作为设计变量,采用MLE理论进行统计分析,建立了基于仿真的步降加速寿命试验优化设计模型。最后通过实例分析,表明该方法具有可行性、有效性,为电子装备寿命预测的加速试验方案优化设计提供技术支撑。     

步降加速寿命试验优化设计Monte-Carlo仿真

针对加速寿命试验存在试验时间长、费用高、效率低的问题,提出了一种基于Monte-Carlo仿真的步降加速寿命试验优化设计方法.采用Monte-Carlo对步降加速寿命试验进行仿真模拟,以正常使用应力下的p阶分位寿命渐近方差估计和各应力水平下的特征寿命之和最小为目标,以各试验应力水平及对应应力下的试验截尾数作为设计变量,采用MLE理论进行统计分析,建立了基于仿真的步降加速寿命试验优化设计模型.最后通过实例分析,表明该方法具有可行性、有效性,为电子装备寿命预测的加速试验方案优化设计提供技术支撑.     

基于正态分布的双应力交叉步阶试验仿真研究

首先针对高可靠、长寿命电子装备的可靠性评估问题,提出一种新的试验方法--双应力交叉步阶试验.而后在正态分布下,通过理论模型的建立,运用Monte-Carlo仿真对该试验的试验效率问题进行深入研究,分析得出形状参数σ、寿命特征参数μ与加速效率指标之间的基本关系.结果表明在实际试验条件下,双应力交叉步降试验与双应力交叉步加试验相比,其试验效率是十分明显的.     

基于粒子群算法的步降加速退化试验优化设计

针对解析方法难以得到或者不能得到步降加速退化试验最优方案的难题,提出一种基于粒子群算法的Monte-Carlo仿真步降应力加速退化试验优化算法。该算法通过大量的重复模拟试验生成试验退化数据,寻找最佳监测频率、检测次数和样本量,以正常使用应力下的对数p阶分位寿命渐近方差估计最小为目标,采用粒子群算法对退化试验数据采用极大似然估计进行统计分析,建立了基于仿真的步降应力加速退化试验优化设计模型。基于算例,给出了不同约束条件下的优化设计方案,得到了该方法也满足小子样产品步降加速退化试验优化设计的结论,并最终得到其最优试验方案。     

竞争失效产品步进加速寿命试验的优化设计

对weibull分布竞争失效产品的步进加速寿命试验进行优化设计,首先选取产品正常应力下中位寿命的极大似然计估渐近方差的估计值作为优化目标函数,并对优化目标函数进行统计推断.然后利用目标函数的连续性,提出基于离散数据的函数拟合方法,将试验优化设计转化为显函数的约束极值求解问题,同时将智能优化算法应用到步进加速寿命试验的优...     

Weibull分布下基于MAM的白光OLED寿命预测

为了得到白光有机发光二极管(OLED)寿命信息,降低试验成本,开展了三组恒定电流应力加速寿命试验。采用Weibull函数描述其寿命分布,基于图分析法(MAM)和MATLAB绘制的Weibull概率双坐标纸,描点作图并估计形状参数和尺度参数,实现了白光OLED的寿命预测。数值结果表明,白光OLED样品在各加速应力下失效机理保持不变,加速模型满足逆幂定律,精确计算的加速参数使得OLED寿命快速估算成为可能。     

基于MAM的真空荧光显示器寿命预测

为了在短时间内得到真空荧光显示器(VFD)的寿命信息,降低寿命预测成本,通过加大阴极温度开展了恒定和步进应力加速寿命试验,建立了加速寿命试验模型,采用威布尔函数描述VFD的寿命分布,在图分析法(MAM)的基础上,基于MATLAB软件强大的计算和可视化绘图功能,绘制了威布尔概率双坐标纸,估计了加速参数,完成了VFD寿命的预测.试验数据的统计和分析结果表明,VFD在各加速应力水平下的失效机理不变,加速模型符合线性的阿伦尼斯方程,基于MATLAB的图分析法使得短时间内精确预测VFD的寿命成为可能.     

对数正态分布下基于MAM的VFD加速寿命试验研究

为了在较短时间内掌握真空荧光显示器(VFD)的寿命信息,节省寿命试验时间,通过开展两组恒定应力加速寿命试验和一组步进应力加速寿命试验,采用对数正态分布函数描述VFD的寿命分布,在图分析法(MAM)的基础上,基于MATLAB软件强大的计算和可视化绘图功能,绘制了对数正态概率双坐标纸,估计了对数均值和对数标准方差,完成了VFD恒定应力和步进应力加速寿命试验数据的统计和分析.结果表明,VFD寿命服从对数正态分布,其加速模型符合阿伦尼斯方程,基于MATLAB的图分析法来实现寿命数据处理是可行的,精确估算的加速参数使得快速预测VFD寿命成为可能.     

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.     

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.     

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.     

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.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.