无氰沉金工艺的实践

介绍了一种新的不含游离氰的镀金盐以及相关的无氰化学沉金工艺,无氰化学沉金工艺沉金金面的均匀性高,可减少黑焊盘(PAD)的产生机率,工艺过程更环保,生产技术成熟,管理措施齐全,金盐供应充足,对不同客户的适应性强.无氰化学沉金工艺已引起PCB同行的高度关注.     

无氰镀金工艺的实践

本文介绍了一种新的不含游离氰的无氰镀金工艺,以及相关的无氰化学镀金工艺特点,包括镀层结构致密,结晶均匀、槽液稳定,杂质容忍度高,过程更环保。与无氰沉金工艺相似,该工艺的生产技术成熟、管理措施齐全、金盐供应充足、对不同客户的适应性强,有望成为替代传统有氰工艺的技术。     

柠檬酸金钾无氰沉金厚度控制研究

柠檬酸金钾化学沉镍金工艺是一种新型无氰沉金工艺。利用单因素变化模拟试验及镀层厚度测试研究了该工艺中反应温度、金盐浓度、添加剂浓度、pH值、副产物等因素对无氰沉金工艺的影响,确定金平均沉积速率随各因素变化的关系,为实际生产中沉金厚度控制提供理论依据。     

SFP光模块PCB制作工艺研究

在SFP光模块PCB高速/高频信号传输存在趋肤效应的条件下,分析了“镀水金+镀厚金”常规工艺信号传输线镀覆镍金对信号传输的影响,研究出“镀厚金+沉金”工艺,实现了信号传输线无镀覆镍金,有利于信号完整性控制,并保证了PCB长短金手指完整性良好(无残缺、无残留镀金导线头、无尖角等异常).     

直接电镀工艺技术

近几年来在PCB工业中受到了多方面的挑战:首先,在环保方面对PCB生产环境及其“三废”处理不断提出了严苛要求;其次PCB孔径也急剧地减小,随之对孔金属化互连(特别是多层板的内连)可靠性须进一步提高;再次,为了避免工艺复杂和难于控制的化学沉铜工艺;最后,也是最重要的是从PCB生     

关于沉金镍腐蚀问题的研究

近年来,在无铅化的大背景下,PCB产业随之发生重大变化,表面处理工艺亦然如此。沉金工艺在诸多选择中可谓异军突起,因其固有的优点,其所占比重迅速提高,当前已经占据PCB总量的半壁江山。但沉金工艺又有其难以克服的顽疾,镍腐蚀问题就是一直困扰沉金的难题。关于镍腐蚀问题,国内外同行都做了许多方面的研究,尽管对镍腐蚀控制取得长足的进步,然而对此问题的认识、理解依旧不尽而一。实际生产中镍腐蚀问题仍是难以根除,沉金焊接性投诉还是时有发生。本章由生产实际出发结合相关实验测试,对镍腐蚀问题的关键影响因素进行了独特的探讨,分析其内在机理,以期能够帮助生产实际,为业内同行改善沉金工艺品质提供切实、有效的参考。     

文献与摘要（78）

高密度挠性电子的丝网印刷;精细线路的批量化生产——显影液控制;Occam工艺：一种新的印制电路制造方法;刚挠技术成主流应用,但设计更复杂;用有机金属对PCB进行纳米表面处理的新技术;世界上有关环境法规动向的背景及相应状况;高速PCB设计研究;无铅化内层板之铜面处理;绿色法规驱动下的电路板技术趋势透析;无氰化学镀金技术的发展及展望;化学镀锡层表面形貌影响因素的研究;无氰置换镀金工艺研究;化学镀镍废液处理的现状及展望;亚硫酸盐—硫代硫酸盐置换镀金液对Ni^2＋1耐受能力的研究;镀镍废水膜法浓缩回用工艺;化学镀锡预镀工艺对镀层质量的影响;压延铜箔电镀Zn-Ni合金工艺研究     

局部镀金与选择性沉金工艺研究

随着电子产品的不断发展,越来越多的客户倾向于采用局部镀金与选择性沉金的工艺设计,满足PCB产品即可耐插拔性能又能满足良好可焊性的双向需求。本文主要针对此类PCB产品的制作工艺进行研究,阐述此类产品在制作过程中的工程设计、工艺流程优化、异常处理及品质提升方案,为业界同仁提供参考。     

电路板绿色制造技术探讨（3）

3．2．3废弃物无害化原则 PCB原材料和制程的设计要避免有害物质的使用。目前在无铅化和无卤化的前提下,许多新型材料也在研发和试用之中,如利用可循环使用的工程塑料代替环氧树脂,可生物降解的环保材料也在研发之中。另外,非甲醛化学镀铜、无氰镀铜、无氰镀金等多项低毒性制程要尽快推出。     

电镀镍金工艺中渗镀问题的探讨

在PCB行业产品的最终表面处理显得至关重要，其不但影响产品的最终外观，而且影响对下游装配的可靠性及可操作性。目前在PCB行业，最终处理方式多种多样，各种方式的特点也各有千秋，常见有热风整平、化学镍金、电镀镍金、有机保焊剂（OSP）、化学沉银等，电镀镍金工艺因其良好的抗蚀性能、优良的可焊性并且兼容各种助焊剂，并能进行多次焊接，故已经得到越来越多的应用。     

筛选技术概述和新的筛选方法

筛选是一种发现产品潜在缺陷的、极为有效的方法。这是一种将产品一边运转一边快建加温和降温，然后在达到高低温极限时再加上振动。有时还加上湿度、电源开／关、抽真空等应力，促使产品缺陷在短时何内暴露出来的过程。由于过个过程既费时又费钱。所以这种筛选方法一直没有得到广泛的应用。为了解决这些问题，提出一种新的筛选方法，可以将筛选的时间从几天降到几分钟，并节省大量的费用，从而提高产品的质量和可靠性。     

筛选技术概述和新的筛选方法(续)

筛选是一种发现产品潜在缺陷的极为有效的方法.这是一种将产品一边运转,一边快速加温和降温,然后在达到高低温极限时再加上振动,有时还加上湿度、电源开/关、抽真空等应力,促使产品缺陷在短时间内暴露出来的过程.由于这个过程既费时又费钱,所以筛选方法一直没有得到广泛的应用.为了解决这些问题,提出一种新的筛选方法,可以将筛选的时间从几天降到几分钟,并节省大量的费用,从而提高产品的质量和可靠性.     

Ammonia recycling and cadmium confinement in chemical bath deposition of CdS thin layers

Cadmium sulfide thin layers in polycrystalline solar cells are produced by chemical bath deposition (CBD). This process produces wastes containing ammonia and cadmium. These two chemicals must be recovered, and if possible recycled, from an environmental and economic point of view. A process has been implemented in order to recover ammonia and to confine cadmium. A new closed reactor has been designed and fabricated in order to trap ammonia vaporized during the deposition step. Ammonia is absorbed from the exhaust gas from the CBD reactor. The wastes are treated in an ex situ process which enables recovery of the major part of the large amounts of ammonia used in the process. Concentrated solutions of pure ammonia are obtained (more than 10 mol/l). In connection with this operation, all of the cadmium, except a very small amount, is precipitated, mainly as cadmium sulfide, owing to decomposition of the thiourea introduced in excess. Microfiltration with a glass‐fiber filter of about 0.7 μm cut‐off produces a filtrate of very low cadmium concentration (< 10 μg/l). Optimization of both pH and residual ammonia concentration should make it possible to lower this residual cadmium concentration. This effluent is the only waste product of the process. The filtration cake containing cadmium compounds may be stored in specialized landfills after standard treatment or, better, treated to recover and recycle the metal without generation of any other harmful effluent. Copyright © 2001 John Wiley & Sons, Ltd.     

火力发电厂能量损耗及节能措施

能源在社会发展过程中属于重要的组成部分,也是动力基础,更是国家经济发展的必要条件.当前在我国的发展过程当中,对煤炭的使用效率还非常低,但是存在的能耗问题却是非常严重,环境的污染问题日益严峻,在此过程当中,为了实现经济能源的可持续发展,需要关注火力发电厂的节能还有损耗性问题,对此,本文对火力发电厂的能量损耗还有节能措施进行更好的使用.     

SiC devices for advanced power and high-temperature applications

Silicon carbide (SiC) process technology has made rapid progress, resulting in the realization of very promising electronic devices and sensors, enabling advanced solutions in power industry and mobile systems. In particular, for electronics working under harsh environmental conditions, SiC devices reach unprecedented performance. Transfer to production has already started for some applications     

无线传感器网络中的定位异常检测

在无线传感器网络中位置信息有着重要应用,但是定位过程容易受到恶意攻击者的攻击或环境因素的干扰。为了增加节点定位的安全性。本文提出一种基于节点部署模型的检测方法用来提高定位的安全性能,该方法独立于节点定位过程,根据节点位置的邻居发现和部署知识的一致性判断节点位置是否异常。在具体的异常判断过程中使用一种由马氏距离定义差异矩阵作为比较工具。最后通过Matlab仿真实验分别从检测率,错误警报率两个方面评估验证了该方法的正确性。     

Integrated circuit design for physical unclonable function using differential amplifiers

A physical unclonable function (PUF) based on process variations on silicon wafers is a very promising technology which finds various applications in identification and authentication, but only a few integrated circuits have been reported so far. As those circuits are vulnerable to power supply noises, switching noises and environmental variations, they lead to a reliability issue such as time-varying or metastable responses. To resolve this issue, this letter proposes a new integrated circuit design for PUFs using differential amplifiers. The feasibility of the proposed circuit has been theoretically analyzed and validated through HSPICE simulations for the previous and proposed circuits.     

A multibit ΣΔ modulator in floating-body SOS/SOI CMOSfor extreme radiation environments

This paper presents the design of an experimental first-order ΣΔ modulator with 4-bit internal quantization, fabricated in a 1.5-μm space-qualified radiation-hard partially depleted silicon-on-sapphire (SOS) digital CMOS process. This converter architecture has been chosen partly to allow investigation into the design of a range of common analog functions with two key issues in mind: one of technology and one environmental. First, both the architecture and the circuit design are optimized using a variety of unconventional techniques to account for the influence of extreme bias-dependent, radiation-induced threshold-voltage shifts of up to 1 V, as well as poor 1/f device noise. Second, the circuitry is specially adapted to accommodate the floating-body behavior of this type of process, wherein drain conductance varies considerably with drain bias and frequency. The design techniques are directly applicable to very large-scale-integration silicon-on-insulator (SOI) design, where similar device physics are encountered. Notwithstanding the severe constraints on the design, the fabricated circuit provides 9.7 bits of dynamic range in a 63-kHz signal bandwidth, only degrading to 9.1 bits after 23 Mrad(Si) of total dose γ radiation     

Business benefits from applied EcoDesign

This work describes the application of EcoDesign (environmentally conscious design) within the electronics manufacturing company Philips and how the process has matured from a case-by-case basis driven by single persons to becoming a standard part of the product creation process of most of Philips' business units. Since it was first introduced, the ecodesign process has gone through many changes, not only to deal with influences from the outside world such as regulation and voluntary industrial agreements, but also, and more important, to allow alignment with existing business procedures and business direction. The scope of the process has widened beyond the product to now include the supply chain, the end of life, and consumer behavior as well. This also means a much closer cooperation with stakeholders beyond the product developer; it also involves the purchasing department, market research, and dialogue with the recycling industry. One of the key processes supporting the ecodesign process is environmental product benchmarking, comparing the Philips product with its direct commercial competitors. As has been the case with the ecodesign process, the benchmarking activity has also matured over time, allowing more product benchmarks while improving the quality of the results. The results are now visible in examples of green marketing and communication as the Philips Consumer Electronics Internet site now displays examples of Green Flagship products. Furthermore, the benchmarking activity is now also used to provide valuable information on original equipment manufacturer (OEM) products and to monitor how competition is backing up claims related to their products' environmental performance. It is not surprising that in its recently revealed new environmental program, Philips again shows commitment to keeping a focus on applying ecodesign and more environmental product benchmarking.     

吊舱冲压空气环控系统研制

吊舱常作为现有飞机的功能扩展舱,悬挂于载机机腹或机翼下,其通常与载机没有环控接口,因此需要自带环控系统为吊舱内设备提供必要的环控保障。直接引载机飞行时的外界空气用于设备环控的冲压空气环控系统是吊舱环控最常见的一种方式,其特别适合低速吊舱,具有简洁、经济、可靠等优点。介绍了某吊舱冲压空气环控系统的研制,特别是对该系统的试验测试进行了详细论述,试验表明该系统的设计是成功的,对类似系统的研制具有一定的参考意义。