乳化清洗工艺和清洗设备的探讨

本文章主要叙述目前替代ODS清洗剂的几种方法。其中乳化工艺清洗技术替代ODS清洗PCB组件是一种比较好的方法。本文着重对本公司在实施过程中的调研方案确定，清洗剂选择，以及“三防”试验工作，进行了探讨。     

宇航用PCB组件的半水清洗工艺研究

PCB组件的清洗是宇航电子产品装联中的重要工序,清洗的质量对PCB组件的可靠性影响极大。针对焊丝手工焊接和免清洗焊膏的再流焊接两种焊接方式进行了全自动半水清洗工艺研究。结果显示随着清洗剂浓度增加清洗效果越好,对清洗后的PCB组件进行了表面离子污染测试,离子污染量仅为0.14μg/cm2;同时还对清洗过程对元器件的标识影响进行了分析,研制了新型的固定工装,防止在清洗过程中PCB组件移动,探索出采用聚酰亚胺胶带保护电连接器腔体,防止多余物进入。     

半水清洗替代ODS清洗PCB的技术探讨

本文主要叙述了ODS清洗剂对大气臭氧层的破坏，从而导致对人类生存环境的危害，介绍了目前替代ODS清洗剂的几种方法。其中半水清洗替代ODS清洗PCB的技术是一种比较好的工艺方法。本文着重对我公司在实施这种方法过程中，设备的选型、清洗荆的选择、清洗技术参数的设定、清洗效果等进行了探讨。     

碳氢溶剂在PCB板清洗应用可行性研究

本文对HZJ-102—1、HZJ-102-2、KX-403碳氢溶剂、CFC-113的电性能作了测量,及其它们对松香的溶解作用进行了试验。根据测试结果,选择KX-403作为清洗剂。为了进一步了解其清洗能力及清洗后对器件的影响,对清洗过的PCB组件板的离子洁净度进行了测量,对电子元器件清洗前后的相关电性能作了对比测试,结果表明其清洗过的PCB组件板的清洁度符合J-STD-001要求,清洗后对各类电子器件没有不良影响,对金属及其电镀层没有不良影响。但标准的对胶带、硅胶等有一定的脱胶作用。     

微波组件半水清洗工艺研究

从清洗剂、清洗温度、清洗时间等方面进行分析和试验,研究了一种新型半水清洗工艺,并且通过重新设计设备工装,最终能在同一个清洗腔内同时清洗大小不同、形状各异的低频电路组件、高频电路小模块和大壳体,并且不会对元器件和电路板造成损伤,大大提高了军工产品的清洗效率,满足军工科研生产单位"多品种、小批量"产品的清洗要求,从而有效替代传统的超声清洗工艺。     

电子清洗的进展

本主要论述了电子元器件焊接后清洗技术的最新进展,包括在清洗中施用的各种清洗剂和化合物、水清洗;半水清洗;有机溶剂清洗工艺及应用的清洗设备。此外还对免清洗工艺的目前现状及将来的发展趋势进行了初步的探讨。     

液晶替代清洗剂的试验与研究④

根据《液晶替代清洗剂的试验与研究工作报告(二)》的工作进度安排,清洗小组人员对清洗设备生产厂家的走访结果进行认真分析之后,于2001年底订购了广州沃柯利环保清洗技术设备有限公司的一台全自动封闭式清洗机。该机安装、调试结束后,清洗技术人员马上进行HEP-2对液晶屏的批量清洗试验,并对清洗后的液晶屏进行多重测试,再次验证HEP-2对液晶屏的清洗效果以及可靠性影响,并确定最终的批量清洗替代工艺方案。目前可提交如下报告:     

LED用蓝宝石晶片湿法腐蚀清洗技术的研究

介绍了蓝宝石晶片的清洗原理：通过分析蓝宝石的表面净化原理和对湿法腐蚀清洗工艺试验的研究,提出了一种适用于工业化生产蓝宝石晶片的清洗剂和净化工艺,满足了LED领域的蓝宝石晶片表面洁净度要求。     

计算机硬盘基片的化学机械清洗技术研究

目前,CMP技术对计算机硬盘基片(盘片)进行抛光,盘片表面粗糙度达到原子级平整,抛光后表面的清洗质量直接关系到CMP最终技术水平的高低.采用静态浸泡实验以及浸泡、擦洗、超声清洗实验,结合一系列的表面微观分析,研究了盘片CMP后清洗过程中的化学作用、机械作用以及清洗剂、清洗方式等物理化学要素对CMP后清洗效果的影响.结果表明,CMP后清洗是一种机械作用、化学作用等综合作用的过程.采用优化的清洗工艺及清洗剂,得到了低腐蚀、高洁净、平整的硬盘基片表面.     

锅炉化学清洗技术的发展(二)——综述及相关问题分析

本文就COG-STN等精细线路高档LCD液晶屏狭缝液晶、电极引脚及玻璃表面的清洗,从非ODS清洗剂、清洗工艺和清洗设备三个方面进行了研究,结果表明使用半水基非ODS清洗剂Fisher2000-1和UEA-8090八槽式水基超声波清洗机清洗能满足产品品质的要求。     

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.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

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.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.