【摘要】本文结合作者多年的印制板设计经验，着重印制板的电气性能，从印制板稳定性、可靠性方面，来讨论多层印制板设计的基本要求。【关键词】印制电路板；表面贴装器件；高密度互连；通孔【Key words】Printed Circuit Board；Surface Mounting Device；High Density Interface；Via一．概述印制板（PCB－Printed Circuit Board）也叫印制电路板、印刷电路板。多层印制板，就是指两层以上的印制板，它是由几层绝缘基板上的连接导线和装配焊接电子元件用的焊盘组成，既具有导通各层线路，又具有相互间绝缘的作用。随着SMT（表面安装技术）的不断发展，以及新一代SMD（表面安装器件）的不断推出，如QFP、QFN、CSP、BGA（特别是MBGA），使电子产品更加智能化、小型化，因而推动了PCB工业技术的重大改革和进步。自1991年IBM公司首先成功开发出高密度多层板（SLC）以来，各国各大集团也相继开发出各种各样的高密度互连（HDI）微孔板。这些加工技术的迅猛发展，促使了PCB的设计已逐渐向多层、高密度布线的方向发展。多层印制板以其设计灵活、稳定可靠的电气性能和优越的经济性能，现已广泛应用于电子产品的生产制造中。下面，作者以多年设计印制板的经验，着重印制板的电气性能，结合工艺要求，从印制板稳定性、可靠性方面，来谈谈多层制板设计的基本要领。
上传时间： 2013-10-08
上传用户：zhishenglu
讨论、研究高性能覆铜板对它所用的环氧树脂的性能要求，应是立足整个产业链的角度去观察、分析。特别应从HDI多层板发展对高性能CCL有哪些主要性能需求上着手研究。HDI多层板有哪些发展特点，它的发展趋势如何——这都是我们所要研究的高性能CCL发展趋势和重点的基本依据。而HDI多层板的技术发展，又是由它的应用市场——终端电子产品的发展所驱动（见图1）。 图1 在HDI多层板产业链中各类产品对下游产品的性能需求关系图 1．HDI多层板发展特点对高性能覆铜板技术进步的影响1.1 HDI多层板的问世，对传统PCB技术及其基板材料技术是一个严峻挑战20世纪90年代初，出现新一代高密度互连（High Density Interconnection，简称为 HDI）印制电路板——积层法多层板（Build—Up Multiplayer printed board，简称为 BUM）的最早开发成果。它的问世是全世界几十年的印制电路板技术发展历程中的重大事件。积层法多层板即HDI多层板，至今仍是发展HDI的PCB的最好、最普遍的产品形式。在HDI多层板之上，将最新PCB尖端技术体现得淋漓尽致。HDI多层板产品结构具有三大突出的特征：“微孔、细线、薄层化”。其中“微孔”是它的结构特点中核心与灵魂。因此，现又将这类HDI多层板称作为“微孔板”。HDI多层板已经历了十几年的发展历程，但它在技术上仍充满着朝气蓬勃的活力，在市场上仍有着前程广阔的空间。
上传时间： 2013-11-19
上传用户：zczc
16 relay output channels and 16 isolated digital input channels LED indicators to show activated relays Jumper selectable Form A/Form B-type relay output channel Output status read-back Keep relay output values when hot system reset High-voltage isolation on input channels(2,500 VDC) Hi ESD protection(2,00VDC) High over-voltage protection(70VDC) Wide input range(10~50VDC) Interrupt handling capability High-Density DB-62 connector Board ID
标签： channels indicators activated isolated
上传时间： 2016-02-15
上传用户：dongbaobao
The Cyclone® III PCI development board provides a hardware platform for developing and prototyping low-power, high-performance, logic-intensive PCI-based designs. The board provides a High-Density of the memory to facilitate the design and development of FPGA designs which need huge memory storage, and also includes Low-Voltage Differential Signaling (LVDS) interface of the High-Speed Terasic Connectors (HSTCs) for extra high-speed interface application.
标签： development developing prototypi provides
上传时间： 2017-01-29
上传用户：jjj0202
Behavioral models are used in games and computer graphics for realistic simulation of massive crowds. In this paper, we present a GPU based implementation of Reynolds [1987] algorithm for simulating flocks of birds and propose an extension to consider environment self occlusion. We performed several experiments and the results showed that the proposed approach runs up to three times faster than the original algorithm when simulating high density crowds, without compromising significantly the original crowd behavior.
标签： Behavioral simulation realistic computer
上传时间： 2017-09-08
上传用户：hanli8870
The CommScope InstaPATCH® 360 and ReadyPATCH® solutions utilize a standards-compliant multi-fiber connector to provide high density termination capability. The connector is called an MPO (Multi-fiber Push On) connector by the standards. In many cases, multi-fiber connector products are referred to as MTP connectors. This document is intended to clarify the difference between the two terms – MPO and MTP.
上传时间： 2017-04-12
上传用户：asdfghjkl1234567890
贴片铝电解电容封装库 SMD Aluminum Electrolytic Capacitors VE Features ‧ 3 ~ 16φ, 85℃, 2,000 hours assured ‧ Chip type large capacitance capacitors ‧ Designed for surface mounting on high density PC board. ‧ RoHS Compliance
上传时间： 2018-05-09
上传用户：angel20041401
The planarization technology of Chemical-Mechanical-Polishing (CMP), used for the manufacturing of multi- level metal interconnects for High-Density Integrated Circuits (IC), is also readily adaptable as an enabling technology in MicroElectroMechanical Systems (MEMS) fabrication, particularly polysilicon surface micromachining. CMP not only eases the design and manufacturability of MEMS devices by eliminating several photolithographic and film issues generated by severe topography, but also enables far greater flexibility with process complexity and associated designs. T
标签： mechanical polishing Chemical
上传时间： 2020-06-06
上传用户：shancjb
Achieving High Power Density Designs
标签： Achieving Density Designs Power
上传时间： 2013-10-12
上传用户：qazxsw
资料->【E】光盘论文->【E1】斯坦福博士论文->03 California PhD High integrity GPS-INS filter for precise relative navigation.pdf
标签： California navigation integrity relative
上传时间： 2013-07-03
上传用户：jiiszha
