LED的LTCC封装基板研究

LTCC基板广泛应用于先进的LED封装技术。阐述了LED的陶瓷封装基板的特点,介绍了制造LTCC封装基板的生瓷片性能和制造工艺,通过对LTCC基板热电分离结构的优点分析,指出金属散热通孔是提高LTCC基板散热效果的关键原因,并展望了LTCC封装基板发展方向。     

LTCC基板制造及控制技术

低温共烧多层陶瓷(LTCC)基板,具有高密度布线,内埋无源元件,IC封装基板和优良的高频特性,目前在宇航、军事、汽车、微波与射频通信领域得到广泛运用,是MCM技术的关键部件.本文介绍了LTCC基板制造的关键技术和性能控制.     

LTCC工艺技术的重点发展与应用

本文主要介绍LTCC工艺制造技术在目前和将来一段时间内的重点发展与应用情况,包括平面零收缩LTCC基板、空腔制作、精密细线条加工、带敏感结构LTCC基板,以及LTCC集成组件与模块、MCM用标准化封装外壳、LTCC用于微系统和传感器等。     

LTCC高精密封装基板工艺技术研究

将激光修调、化学镀、光刻等技术与常规低温共烧陶瓷(Low Temperature Co-Fired Ceramic,LTCC)基板工艺技术相结合,对LTCC高精密封装基板的制作工艺进行开发和优化,并利用9K7材料进行了基板试制。结果显示,基板表面线条细度达到(50±5)μm,表面导体图形位置精度优于±10μm。基板表面Ni/Pd/Au镀层可焊性/耐焊性优良,2 mm×2 mm焊盘的锡铅焊接拉力强度达到2.8 kg以上,25μm金丝的键合强度达到10 g以上。基板表面阻焊开口尺寸达到(80±10)μm,具有良好的阻焊性能。对试制的LTCC高精密封装基板进行了装配和测试,在12 mm×13 mm的尺寸上实现4颗射频芯片的倒扣装配,功能模块在W波段具有良好的射频性能。LTCC高精密封装基板显现出高密度、高性能封装能力。     

微组装中的LTCC基板制造技术

微组装是指在高密度多层电路基板上,采用微焊接和封装工艺将构成电路的各种半导体集成电路芯片或微型器件组装起来,形成高密度、高可靠的立体结构.通过对微电子组装及LTCC基板制造技术国内外发展、应用概况介绍,分析了LTCC基板材料技术、低温共烧技术等关键技术的发展方向.     

大尺寸LTCC焊接组件热变形特性的仿真研究

为了研究不同封装条件对低温共烧陶瓷(LTCC)基板封装焊接后残余热应力的影响,该文针对不同温变载荷下LTCC基板的热应力变形进行了仿真计算和实验测试,结果显示仿真计算与实验测试结果具有较好的一致性,验证了数值仿真用于LTCC基板封装焊接后残余热应力仿真的可行性。在此基础上对零膨胀合金底板和硅铝合金封装条件下3种典型工作温度对应的LTCC基板的热应力进行了仿真计算。结果表明,封装焊接后LTCC基板两侧边缘应力集中,中间残余应力小,呈翘曲状态,采用硅铝合金封装焊接的热应力小于零膨胀合金封装。     

多通道小型化三维封装T/R组件

<正>南京电子器件研究所最近研制出一款用于有源相控阵雷达用的多通道TIR组件,该组件采用三维封装技术,利用LTCC多层基板可实现微波电路的三维信号传输的特点,采用LTCC基板封装一体化设计方法,提高组件的     

LTCC基板材料研究进展

LTCC是现代微电子封装中的重要组成部分，因其性能优良而广泛应用于高速、高频系统中，从而成为研究热点。LTCC基板材料的性能决定最终封装的质量，故基板材料的研究在LTCC的进展中发挥了重要作用。LTCC基板材料可分为两大类：微晶玻璃和玻璃／陶瓷。分别介绍各类基板材料的性能、组成和应用方面的情况，并对国内外进行各类材料研究进展进行概述，提出基板材料未来的发展方向。     

LTCC曲面基板制造技术

电子电路曲面结构对于实现结构功能一体化有重要应用意义。针对LTCC多层电路基板,提出了一种曲面结构基板的加工制造方法。介绍其制造中曲面结构导体制作、曲面结构成形、曲面结构烧结等环节的关键制造工艺。通过X光和剖切方式对所制造的曲面基板进行测试分析,结果证实曲面基板中的多层布线均连通,且层间对位精度优于15μm。提出的曲面LTCC基板制造技术能够满足后续产品的研制加工要求,对于曲面电子技术和LTCC技术的发展都具有借鉴意义。     

低温共烧陶瓷基板及其封装应用

低温共烧陶瓷LTCC基板是实现小型化、高可靠微波多芯片组件MMCM的一种理想的封装技术一文章对LTCC技术的特点及应用做出了评述,主要介绍国内外LTCC的现状、发展趋势与问题,同时突出强调了LTCC的飞速发展及对微波器件的重要性。     

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.     

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 rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks