多层印制板叠层设计对信号完整性的影响研究

基于优化多层印制板叠层设计改进信号完整性的目的,提出了通过叠层设计中调整印制板各层导线宽度、基板厚度、填充层厚度和绝缘材料厚度4个参数值,以改变各层信号传输路径特性阻抗的方法,结合工程实例,通过在特性阻抗连续和阻抗不连续两种情况下仿真的对比试验,验证了叠层设计优化方法的有效性.     

汽车用厚铜多层板的工程设计与制程控制

近年来汽车用PCB订单需求迅猛,文章立足于PCB厚铜板在生产过程中最易发生的品质问题,重点阐述了与此密切相关的工程资料设计(板材选用、拼板设计及其线路设计等)及生产控制要点(层压、蚀刻、感光丝印等),有效改善了此类多层板的品质。     

New high-density multilayer technology on PCB

Demand has recently increased for very high-density packaging substrates for high-pin-count area array chips. Our new high-density multilayer technology on printed circuit board (PCB), named deposited substrate on laminate (DSOL) satisfies this demand. An important feature of the DSOL is dielectric fabrication, which uses a new photosensitive material; an aromatic fluorene unit bonded epoxy acrylate resin. The fluorene based resin has interesting properties such as good electrical properties, low curing temperature (160°C) for a heat-resistant resin (glass transition temperature, T_g=230°C), low coefficient of the thermal expansion (40 ppm), and excellent via hole resolution. Very fine and high-aspect-ratio (>1.0) via holes were formed through exactly the same process steps as those used for a conventional photosensitive epoxy resin; baking, exposure, and development with an aqueous alkaline solution. Another important feature is the technology, that patterns fine-pitch Cu conductors using a semi-additive process with a sputtering method. The DSOL made 40 μM very fine pitch Cu conductors on large laminates (330 mm×400 mm) possible, because this process was composed of flash wet etching of only 0.3 μm thick sputtered thin-films. We have successfully developed a high-density packaging substrate for high-pin-count (4000 pins) area array application specific integrated circuit (ASIC) chips     

混合印制电路板的电磁兼容设计

结合PCB设计的经验，首先探讨了包含高速、高频信号PCB设计中电磁兼容性的基本问题，接着给出针对高速数模混合信号PCB设计中具体的电磁兼容设计原则和方法。     

PCB铣加工中的简单数学原理

PCB铣加工中尺寸变化的规律与其数学原理相关,了解这些原理对铣程序设计优化和产品尺寸稳定大有裨益,文章根据实际生产经验对常见的规律性问题进行简单分析,以期抛砖引玉。     

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。     

多层板内层铜箔棕化处理液研制

文章概述了应用于PCB多层板制作过程中的棕化工艺原理及棕化膜的结构。主要讨论了一种新的棕化处理液,包括配方组成和工艺方法。经实验和应用实践证明,它具有能够显著促进铜面与粘结片的结合力,耐高温热冲击-陛能良好,抗剥离强度高,没有粉红圈,工艺流程简单,适用性广,成本低等特点。     

超厚铜多层印制电路板制作工艺探讨

主要针对411．6μm（单位面积铜重量：12oz／ft^2超厚铜箔多层PCB的制作工艺进行研究,采用铜箔反面蚀刻＋压合＋正面蚀刻的技术,有效解决了超厚铜蚀刻困难和压合填胶困难等业界常见的技术难题,保证线路的蚀刻质量和压合的效果。极大提升了品质,满足了客户的特种需求。     

PCB成型产能技术分析

文章从影响铣成型产能的因素入手并逐项进行分析,对如何降低成本,提高效率,同时保证产品品质进行了较为详细的论述,并通过实际应用取得了较为理想的成绩。     

高层板对位精度计算模型研究

测量影响高层板对位精度的因素的精度及其标准偏差,并采用瑞利分布函数预测不同对位精度对应的成品合格率,在此基础上,确定了需要优先改进的工序及其标准偏差控制要求,为从定量的角度优化关键因素提供了有效的方法。     

聚四氟乙烯多层印制板孔互连分离的改善

1 问题提出多层板孔互连分离问题是指内层铜与孔壁铜分离,普通环氧树脂板材多层板很少出现孔互连分离问题,但聚四氟乙烯多层板由于其材料特殊性,易产生孔互连分离.产生孔互连分离主要是在钻孔过程中产生的胶渣过多或者孔金属化前除胶渣能力不足造成,如图1.     

Prediction-based routing as RWA in multilayer traffic engineering

Multilayer traffic engineering (MLTE) allows coping with ever-increasing and varying traffic demands in IP-over-Optical multilayer networks. It utilizes cross-layer TE (Traffic Engineering) techniques to provision optical lightpath capacity to the IP/MPLS (Internet Protocol/ Multi-Protocol Label Switching) logical topology on-demand. Such provisioning however causes optical connection arrival rates that pose strong performance requirements to Routing and Wavelength Assignment (RWA) strategies. Collecting up-to-date network information for the RWA with rapidly changing network states can be quite difficult. Exposing optical layer state information to the IP layer in the overlay model, or transforming this optical layer information in a workable representation in an integrated control plane is similarly problematic. Prediction-Based Routing (PBR) has been proposed as a RWA mechanism for optical transport networks; it bases routing not on possibly inaccurate or outdated network state, but instead on previous connections set-up. In this article, we propose to implement PBR as the RWA mechanism in the optical layer of a multilayer network, and use the predictive capabilities of PBR to expose dynamic optical network information into the multilayer traffic engineering algorithm with minimal control plane overhead. Some simulations show the benefits of using the PBR in the optical layer for MLTE purposes.     

印制电路板的抗干扰设计

以印制电路板的电磁兼容性为核心,分析了电磁干扰的产生机理,介绍在设计、装配印制电路板时应采取的抗干扰措施。     

RSA密码协处理器的实现

密码协处理器的面积过大和速度较慢制约了公钥密码体制RSA在智能卡中的应用.文中对Montgomery模乘算法进行了分析和改进,提出了一种新的适合于智能卡应用的高基模乘器结构.由于密码协处理器采用两个32位乘法器的并行流水结构,这与心动阵列结构相比它有效地降低了芯片的面积和模乘的时钟数,从而可在智能卡中实现RSA的数字签名与认证.实验表明:在基于0.35μm TSMC标准单元库工艺下,密码协处理器执行一次1024位模乘需1216个时钟周期,芯片设计面积为38k门.在5MHz的时钟频率下,加密1024位的明文平均仅需374ms.该设计与同类设计相比具有最小的模乘运算时钟周期数,并使芯片的面积降低了1/3.这个指标优于当今电子商务的密码协处理器,适合于智能卡应用.     

工作研究在PCB成型效率提升中的应用

改善生产要素组织,提高生产率是企业生产管理的永恒课题。针对我公司成型工序中存在的生产率低、工序步骤安排不合理等问题,应用工作研究的程序分析技术,首先阐述了成型工序的现状,然后用流程程序分析法优化工艺流程。通过改进,缩短了生产周期,提高了生产效率,从而使产能提高了5％。     

印制电路板的物理设计三要素

印制板电路是通信设备的重要组成单元,现代高科技电子战对印是电路板提出了更高的要求,而且环境越来越恶劣,需要解决很多关键技术,而其中的电磁兼容性设计、热设计、防振动抗冲击设计则构成物理设计三要素,妥善合理地解决好这个设计三要素对实现印刷 制电路板的高性能、高可靠性有着深远的意义。     

表面组装印制电路板基准标记的可制造性设计

对表面组装印制电路板基准点的可制造性设计进行了详细的阐述,内容含概了定位标记的分类、标记对形状、组成、位置、尺寸、边缘距离、空旷度、材料、平整度和对比度等方面的要求,并对不良标记设计列以实例说明,最后以Protel99se软件为例,详细阐述了标记的设计过程。对表面组装印制电路板基准点的可制造性设计有指导和规范性的作用。     

Automated pin grid array package routing on multilayer ceramicsubstrates

In the packaging router, routing is divided into two phases: topological routing and physical routing. Topological routing determines the topology of the paths layer by layer. Instead of using minimal spacing rules, for the given electrical constraints, the algorithm uses weighted spacing rules to optimize I/O performance. Physical routing builds the detailed structures of the connections. It permits variable RLC trade-offs. The overall time complexity is linear in the number of I/O pins. A practical packaging router was implemented. The experimental results show that this routing tool significantly improved the performance and the productivity of packaging design     

A hierarchical multilayer QoS routing system with dynamic SLAmanagement

This paper proposes a hierarchical multilayer QoS routing system with dynamic SLA management for large-scale IP networks. Previously, the promising approach to provide QoS in large-scale IP networks using a mixture of DiffServ-based QoS management and MPLS-based traffic engineering has been actively discussed. However, the introduction of QoS exacerbates the already existing scalability problems of the standard IP routing protocols. In order to address this issue, we propose a new scalable routing framework based on hierarchical QoS-aware path computation. We augment the existing OSPF and CR-LDP protocols to support hierarchical QoS routing, QoS aggregation, and QoS reservation in our MPLS-DiffServ-based hierarchical routing network. In order to provide additional flexibility and cost-efficiency, we augment the network with a policy server which is capable of dynamically handling SLAs between the networks and providing load balancing management within the network. We implement a prototype of the proposed framework and study its performance with a virtual network simulator and specially designed QoS routing algorithm simulator. In our simulations, we evaluate both the implementation complexity and algorithms performance; the results demonstrate the efficiency of the framework and its advantages over the existing proposals     

PCB制前设计成本控制浅谈简

文章主要讲述PCB制前设计对其生产制作成本的影响,从而给设计者提供了一套实用的参考资料,告诉设计者在日常工作中需要关注哪些项目,才能使用最低的制作的成本,设计出满足客户需求的产品。