可延展柔性无机电子互连结构及其力学特性北大核心

首先简要介绍了目前实现可延展柔性无机电子延展性的主要原理及方式,分析了目前存在的问题;其次,总结了目前提高可延展柔性无机电子延展性能的主要设计,并对可延展柔性无机电子互连结构的力学特性发展现状进行了分析。其中重点探讨了目前存在的互连导线失效、异质界面的力学及其可靠性问题的研究现状;最后,针对目前可延展柔性无机互连结构存在的界面可靠性问题,介绍了本课题组在该方面的数值仿真工作。主要分析了可延展电子典型互连结构单元——马蹄形、Z字形结构基底应力集中问题,并进行了上述结构界面剥离的仿真分析。     

柔性电子封装技术与应用

电子封装为芯片提供机械支持、环境保护、电信号引出端和散热通道等重要功能,为了获得较高可靠性,传统封装采用硬质材料体系,难以满足新兴的生物医疗、可穿戴电子、可折叠显示、曲面电子器件等技术领域需求,柔性电子封装颠覆了传统电子系统刚性形态特征,被认为是最有可能实现颠覆性技术创新的领域之一,文中对柔性封装技术及产品的应用领域进行了介绍,并从芯片、基板和封装体三个层面阐述了柔性封装技术的实现方法及面临的挑战,最后,介绍柔性混合电子技术的发展并展望了未来柔性电子技术趋势。     

可延展柔性电子基底微观分析北大核心

可延展柔性电子产品在可穿戴电子、柔性显示和医疗等领域中具有很大的应用潜力。在可延展柔性电子的应用中,可延展柔性电子基底与互连导线之间的可靠性研究受到越来越广泛的关注。以可延展柔性电子界面为研究对象,从微观机理出发讨论可延展柔性电子界面的可靠性问题,运用分子动力学(MD)的方法建立基底的微观模型。用掺杂的方式优化基底的各项性质,以提高可延展柔性电子界面的可靠性。在聚二甲基硅氧烷(PDMS)基底中掺杂SiO_2纳米粒子后的复合物,经分子动力学仿真分析得出,基底热膨胀系数随着掺杂SiO_2原子数分数的增大而减小;杨氏模量随着掺杂SiO_2原子数分数的增大而增大。这说明加入SiO_2可以很好地提高PDMS的机械特性和降低基底的热膨胀系数,使优化后的基底更加适合与互连导线结合,提高整体的可靠性。     

激光制备液态金属基柔性电子及其应用

随着科技的发展,柔性电子器件在医疗健康、柔性机器人以及人机交互领域中的应用越来越广泛。柔性电子器件的关键在于柔性电极材料,传统柔性电极材料如结构化的金属薄膜、金属纳米颗粒/线以及导电聚合物等存在高延展性与高导电性无法同时满足的问题。镓基液态金属作为一种室温下呈现液态的金属材料,具备金属高导电性的同时也具有无限延展性,是一种理想的柔性电极材料,是近年来的研究热点。对液态金属进行图案化处理是制备液态金属基柔性电子器件的必要环节。重点介绍了以浸润性调控的方法实现液态金属图案化的工艺。激光作为一种精密加工方式,被常用来制备各种功能表面,同时也是调控液体浸润性的主要手段之一。结合激光的高精密加工能力与液态金属优异的电学性能,能够实现高分辨率、多功能以及高集成度的液态金属电子器件制备。综述了近年来国内外在激光制备液态金属柔性电子器件方面的主要工作,并展望了未来激光制备高性能液态金属电子器件的前景。     

把电子器件化成绕指柔

电子器件和电流的关系就像液体和容器的关系一样,只不过这个容器一直是个坚硬的搪瓷杯子。不过,这个概念可能要被打破了。因为,能任意扭曲的电子器件已经出现了,这也意味着刚性电子技术开始向柔性电子转变。     

等离子辅助化学气相沉积制备可延展的硅薄膜

利用等离子辅助化学气相沉积方法在单晶硅基底表面制备出可延展的硅薄膜.通过对薄膜生长过程的观察,确定延展性是最终脆性硅薄膜生长的中间状态,实验证明,沉积层表现出的延展性与螺旋带等柔性材料存在本质差别,需要小于临界厚度才能呈现柔性状态的机理并不适用,沉积工艺导致的内部结构的差异才是根本原因.但沉积层中Si原子以何种晶格结构排列并且何以导致如此强大的延展性,还有待进一步研究.     

基于喷墨打印银基无颗粒油墨的柔性电极

柔性电极是柔性电子的基础组成部分,而低成本快速制备高性能柔性电极是柔性电子发展的基础问题之一。基于银基无颗粒银基油墨,利用低成本的家用喷墨打印机实现了柔性聚酰亚胺衬底上的导电电极的打印制备。经过热烧结处理后,得到了的柔性电极展示出优良导电性,良好的柔性弯曲特性和较强的附着力可作为柔性电路板实现良好的电连接,在此基础上实现了电容性柔性触摸按键。本文对制备低成本、易操作的柔性电路及柔性电子器件具有参考价值。     

瞬态电子技术及其军事应用

基于可降解材料的瞬态电子器件,在完成指定功能或废弃后,受预定触发因素刺激,可实现短时间内部分退化或全部降解.凭借先进加工工艺和特殊的功能材料,瞬态电子器件在性能方面可与传统电子器件相媲美,并在功能上形成补充,将应用范围扩展到绿色电子、信息安全存储、植入式医疗和环境监测传感器等前沿领域.文章综合分析了瞬态电子的概念、组成、制造技术、降解机理以及重要瞬态器件,从信息安全存储、战场侦察监视、士兵伤情防治、物资精确投送4个方面,阐述了瞬态电子技术在军事方面的应用.总结了瞬态电子技术发展存在的问题,展望了其未来研究的发展趋势.     

瞬态电子技术发展现状

瞬态电子器件是一种在使用阶段稳定运行、在特定条件下触发实现自动销毁或降解的新型先进电子器件。瞬态电子技术作为构建绿色电子和生物医学设备的基础,近年来受到越来越多的关注。文章介绍了瞬态电子器件的材料、加工工艺、触发机制和重要瞬态器件,对瞬态电子领域的未来发展趋势作出了展望。     

应用于柔性电子领域的激光剥离技术进展

柔性电子是可穿戴设备、物联网等应用发展的重要研究方向。激光剥离技术是一种利用激光能量来分离玻璃基板与柔性衬底的技术,具有作用光波长可选、作用时间短、热影响区域小的优点,是目前实现柔性电子器件的最重要技术之一。介绍了激光剥离的主要技术特点,分析其在不同的柔性电子领域的应用,讨论了应用过程中的主要工艺和作用,并总结了激光剥离技术未来的发展趋势。激光剥离技术的快速发展,会对柔性电子行业的研究和发展形成强力支持。     

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.