激光驱动复合飞片加载金属箔板的成形能力

激光驱动飞片加载金属箔板成形技术是一种新型微成形技术,其飞片的结构和性能是影响该技术成形能力和质量的主要因素之一。通过Spitlight 2000Nd:YAG激光器探究了复合飞片(主要由黑漆吸收层、聚酰亚胺隔热层和铝飞片组成)对激光驱动飞片加载金属箔板成形性能的影响。实验结果表明复合飞片能够增大工件的最大成形深度,同时工件形貌中心与模具中心的对中性更好,证明复合飞片在成形过程中对冲击波具有增压和均压作用,能够提高该技术的成形能力和质量。讨论了复合飞片提高成形能力和质量的原因,同时探究了激光能量和聚酰亚胺薄膜厚度对成形性能的影响。     

铜箔激光冲击微成形微观组织与残余应力研究

为了研究激光成形方式对成形轮廓和微观组织的影响,采用厚度为40μm和80μm的T2铜箔进行激光冲击微胀形和微拉深实验。同时使用ABAQUS有限元仿真对实验进行模拟,研究不同变形方式下箔材位移和残余应力场。结果表明,激光冲击微胀形后铜箔变形区域出现颈缩,激光作用区域内变形机制主要为位错滑移、变形扭曲晶粒和机械孪晶;箔材上表面（激光冲击表面）为残余拉应力,最大值约为372.3MPa,箔材下表面（背向激光冲击面）为残余压应力,最大值约为-218.7MPa;而对于微拉深,箔材成形轮廓过渡圆滑,厚度分布均匀,光斑作用区域内出现大量位错露头和一些机械孪晶,箔材上表面为残余压应力,最大值约为-365.6MPa,箔材下表面为残余拉应力,最大值约为203MPa。这一结果对激光冲击箔材成形控制是有帮助的。     

激光驱动飞片加载金属箔板成形实验研究

提出了一种新的微成形方法--激光驱动飞片加载金属箔板微成形技术,结合飞片速度模型和加载压力模型阐述了成形机理,利用10μm厚的铝箔进行了初步成形实验.在体式显微镜下观察成形后的铝箔表面光滑,并且与模具的贴合程度较高,表现出很好的成形精度.考察了激光能量对铝箔成形深度的影响.通过表面轮廓形貌测量仪检测发现,成形深度受激光能量的影响比较大.在光斑直径为1 mm,单脉冲激光能量为25～40 mJ时,铝箔成形深度随激光能量基本呈线性关系增加,单脉冲激光能量在45～50 mJ时,铝箔由于破裂成形深度大幅增加.     

金属箔材无模激光多点冲击成形工艺研究

为了解决金属箔材微拉深工艺中高昂的微型模具设计制造成本问题,采用无模具激光冲击微成形方法,对脉宽5ns、直径50μm的高重复频率激光光斑微冲击成形20μm厚T2铜箔进行了理论分析和实验验证。结果表明,在约束层没有破损的情况下,凹坑深度h、凹坑底平面直径L₁和凹坑壁倾斜程度（L-L₁）随着单脉冲能量E及光斑搭接率增加线性增大;激光扫描内外圆周顺序对凹坑深度没有影响,但会对凹坑底平面直径有影响,先扫描外圆周时会形成更大的凹坑底平面直径,无需模具,凹坑形貌是可控的。这一结果对激光无模微拉深渐进成形的进一步研究是有帮助的。     

激光动态柔性微弯曲中尺寸效应的实验研究

制备了多特征尺寸微弯曲模具,并利用激光动态柔性成形技术实现了单次脉冲下箔板的等压弯曲成形。为了研究工件尺寸(厚度)、晶粒尺寸对高应变率下箔板变形行为的影响,使用超景深显微系统观测成形件三维形貌及轮廓形状,采用纳米压痕仪测量其厚度方向上的微硬度分布,并借助冷镶嵌技术测量成形件厚度减薄率。实验结果表明:铜箔厚度由50μm减小到30μm时,材料流动应力减小,成形件轮廓形状由圆顶状转变为槽状,表面硬度由于模具底部的碰撞滑移得到显著强化;相比于细晶成形件,粗晶件的微塑性成形能力较差;工件底部回弹形变及厚度方向应变硬化不均匀;圆角处易于破裂,最大减薄率比细晶件增大约10%。     

微尺度激光弯曲成形数值模拟与实验研究

建立了厚度为0.1mm的不锈钢钢箔激光弯曲成形的三维热力耦合有限元模型,并采用有限元软件MSC.Marc模拟计算得到了箔材弯曲变形过程中的温度场、变形场与应力应变场。分析了应力、温度、变形三者之间的内在关系,阐述了激光弯曲成形的温度梯度机制(TGM)。建立了微尺度激光弯曲成形的实验装置,验证了有限元模型(FEM)的可靠性,模拟计算结果与实验结果吻合较好。通过实验分析了激光功率、扫描速度以及激光扫描次数等工艺参数对激光弯曲角度的影响规律,并对影响原因进行了初步分析,为进一步对微尺度激光弯曲成形机制及工艺的研究打下了基础。     

激光驱动飞片加载金属箔板成形的加载机制

介绍了激光驱动飞片加载金属箔板成形的方法.采用激光驱动飞片的Gurney模型,计算得出功率密度0.64 GW/cm2时,10μm厚的铝飞片速度可达到250 m/s,碰撞压力为1.9 GPa,是约束模型下激光诱导压力的3倍左右.表明激光驱动飞片加载的成形能力显著高于激光直接冲击;采用LS-DYNA软件数值模拟了激光驱动飞片加载铝箔微成形过程,发现冲击载荷下飞片应力、速度变化的模拟结果与理论计算吻合度较好,验证了激光驱动飞片加载机制的正确性.     

多层金属复合板激光冲击柔性微成形实验研究

研究了一种多层金属复合板激光冲击柔性微成形(LSFF)的新工艺,验证了该工艺的可行性,发现在合适的工艺参数下,成形件没有层裂或裂纹等缺陷。研究结果显示,在LSFF下,镍/铜/镍金属复合板的成形深度介于铜箔和镍箔的之间,且成形深度随着激光能量和激光冲击次数的增加而增加。成形件表面发生了粗化现象,且其粗糙度随着激光能量的增加而增加。     

多脉冲激光冲击微胀形的成形极限及断裂模式

针对T2紫铜箔材开展了多脉冲激光冲击微胀形实验,研究了激光功率密度、初始晶粒尺寸和箔材厚度对胀形极限的影响,分析了断裂工件的宏观和微观断口形貌,讨论了箔材在多脉冲激光冲击微胀形时的断裂模式,并分析了各断裂模式的产生机理。研究结果表明:激光功率密度会显著影响箔材断裂前可承受的最大脉冲次数,但多脉冲成形方式不能提高箔材的胀形成形极限;晶粒尺寸和特征尺寸对多脉冲激光冲击微胀形成形极限具有显著影响;紫铜箔材在多脉冲激光冲击微胀形时存在拉伸断裂、剪切断裂、混合断裂和层裂4种断裂模式。     

3003铝合金激光冲击微挤压成形研究

微挤压模约束下的激光冲击微体积成形技术是利用激光诱导的冲击波使局部金属在凹模约束下产生体积变形的一种成形新技术。为了分析不同板厚(0.12mm,0.15mm,0.17mm和0.22mm)的3003铝合金在不同凹模孔径(0.4mm,0.7mm,0.9mm和1.1mm)约束下的成形深度,采用建立有限元模型进行数值分析的方法,进行了理论分析和实验验证,取得了不同板厚和不同孔径成形下成形深度的数据。结果表明,成形深度随板厚的增大而增大趋势逐渐减小;对于同一厚度,板料成形深度随孔径的增大呈非线性增大趋势;对于同一点冲击,冲击次数对板料的成形深度影响很大。数值分析结果与实验吻合度较好,这一结果对微体积成形质量控制是有帮助的。     

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.     

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.     

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.     

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.