厚铜多层印制板的工程设计与生产控制

文章分析了厚铜多层印制板的主要制作难点,如内外层厚铜线路制作、厚铜多层印制板压合、厚铜多层印制板钻孔、厚铜多层印制板阻焊印刷等。针对主要制作难点,文章介绍了如何从板材和半固化片选用,压合叠层结构优化,内层线路图形设计补偿,钻孔设计,阻焊设计等工程设计手段来提高产品可靠性,以及介绍了重要制作工序的生产控制要点,有效提高了厚铜多层印制板的品质可靠性。     

印制电路板生产中的阻抗控制

本文通过对多层印制板几种传输线结构的描述,提出影响印制板特性阻抗变化的主要因素。重点围绕在实际生产中如何控制这些主要因素,以实现对特性阻抗控制的问题进行了几点讨论,并提出了解决方案。     

印制电路板生产中的阻抗控制

本通过对多层印制板几种传输线结构的描述，提出影响印制板特性阻抗变化的主要因素。重点围绕在实际生产中如何控制这些因素，以实现对特性阻抗控制的问题进行了几点讨论，并提出了解决方案。     

PCB层间介质层厚度探讨

PCB生产实践中,有阻抗控制要求的印刷板,需在PCB制造中对板材的介电常数、导线的宽度和厚度、结构等加以控制,多层板中一旦特性阻抗控制不好,造成高速传输信号过程中和终端出现损耗损失、衰减失真、信号重叠、杂乱等现象,因此必须严格管控PCB层间介质层厚度。本文通过对PCB层间介质层厚度探讨,并针对此进行设计改善、控制。     

集成元件印制板技术

集成元件印制板是把无源元件(如电阻、电容和电感)分别或综合集成到PCB(印制板)内层而形成的,它是新一代HDI/BUM板发展的一个重要方面,并且随着集成电路(IC)的高集成化、高频信号和高速数字信号传输的发展,要求印制板有更好的特性阻抗和更小的电磁干扰,采用集成元件印制板既能提高印制板的高密性又能达到更好的特性阻抗匹配和更小的电磁干扰.介绍了集成电容印制板和集成电阻印制板的材料及工艺过程.     

PCB设计的阻抗控制和阻抗匹配

阻抗设计是PCB可靠性设计的一个重要环节.本文从多层PCB板叠层的设计原理、特性阻抗的计算方法、严格的阻抗控制,来保证阻抗匹配,实现PCB的可靠性,使产品稳定的工作.     

行波型LiNbO3电光调制器的电极优化设计

利用扩展点匹配方法对厚电极厚缓冲层的共面波导电光调制器的结构和性能参数进行了分析和研究,通过仿真选择合适的电极厚度和缓冲层厚度,所得的特性阻抗和有效折射率与采用保角变换法得到的结果吻合,优化了调制器性能,实现了宽带调制.这一分析方法简便快捷,能够处理电极有一定厚度的多层光波导调制器结构.     

印制板特性阻抗的精确测试技术

随电子产品信号完整性要求的增加,印制板特性阻抗控制精度要求增严。特性阻抗的高精度控制是产品设计、过程控制与测量技术三者的综合体现,但阻抗测试不准或判断失误将让前述二者前功尽弃。为了更深入的探讨特性阻抗的测试技术,本文在简述TDR测试原理和测试方法的基础上,详尽介绍了TDR测试曲线与设计资料间的密切关联和阻抗板件生产过程中的阻抗监测技术,并首次阐述了阻抗测试过程中的阻抗不匹配对阻抗测量结果的影响。     

积层印制板种种

当前印制电路板制造技术的热点是积层法制造多层印制板,在日本尤其热门,我国也在引入之中。本文介绍一些日本公司采用积层法制造印制板的多种实例,可让我们加深对积层印制板的认识。 1 日本IBM株式会社之SLC 1.1结构和特征日本IBM株式会社开发、制造的表面层压电路板(SLC: Surface Laminar Circuit)是用液态感光性环氧树脂为绝缘层的一种典型的顺序叠层而成的积层印制板。IBM已完成了SLC的设计、试制、安装使用、可靠性评价等,作为积层印制板已用于BGA、MCM、FCA等安装中,获得成功。SLC的一般结构,在1997年生产出了20层的BGA母板(在12层芯基板上积层4 4层)。     

本征层厚度对非晶硅叠层电池电流匹配的影响

采用PECVD技术制备a-Si:H/a-Si:H叠层双结非晶硅电池,研究了本征层厚度对叠层电池功率及短路电流的影响。通过调节顶电池和底电池本征层的沉积时间,得到不同厚度比例的本征层(di1:di2),经过实验对比发现I层总体厚度为650 nm,di1:di2=1:5时得到的电池组件短路电流(Isc)和最大功率(Pmax)都是最大值。此时叠层电池的电流得到了较好的匹配,实现了工艺参数的优化。     

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.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

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.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

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.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

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.     

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.     

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.