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: 2013-11-22
上传用户:gundan
PCB LAYOUT 術語解釋(TERMS)1. COMPONENT SIDE(零件面、正面)︰大多數零件放置之面。2. SOLDER SIDE(焊錫面、反面)。3. SOLDER MASK(止焊膜面)︰通常指Solder Mask Open 之意。4. TOP PAD︰在零件面上所設計之零件腳PAD,不管是否鑽孔、電鍍。5. BOTTOM PAD:在銲錫面上所設計之零件腳PAD,不管是否鑽孔、電鍍。6. POSITIVE LAYER:單、雙層板之各層線路;多層板之上、下兩層線路及內層走線皆屬之。7. NEGATIVE LAYER:通常指多層板之電源層。8. INNER PAD:多層板之POSITIVE LAYER 內層PAD。9. ANTI-PAD:多層板之NEGATIVE LAYER 上所使用之絕緣範圍,不與零件腳相接。10. THERMAL PAD:多層板內NEGATIVE LAYER 上必須零件腳時所使用之PAD,一般稱為散熱孔或導通孔。11. PAD (銲墊):除了SMD PAD 外,其他PAD 之TOP PAD、BOTTOM PAD 及INNER PAD 之形狀大小皆應相同。12. Moat : 不同信號的 Power& GND plane 之間的分隔線13. Grid : 佈線時的走線格點2. Test Point : ATE 測試點供工廠ICT 測試治具使用ICT 測試點 LAYOUT 注意事項:PCB 的每條TRACE 都要有一個作為測試用之TEST PAD(測試點),其原則如下:1. 一般測試點大小均為30-35mil,元件分布較密時,測試點最小可至30mil.測試點與元件PAD 的距離最小為40mil。2. 測試點與測試點間的間距最小為50-75mil,一般使用75mil。密度高時可使用50mil,3. 測試點必須均勻分佈於PCB 上,避免測試時造成板面受力不均。4. 多層板必須透過貫穿孔(VIA)將測試點留於錫爐著錫面上(Solder Side)。5. 測試點必需放至於Bottom Layer6. 輸出test point report(.asc 檔案powerpcb v3.5)供廠商分析可測率7. 測試點設置處:Setuppadsstacks
上传时间: 2013-10-22
上传用户:pei5
This document provides practical, common guidelines for incorporating PCI Express interconnect layouts onto Printed Circuit Boards (PCB) ranging from 4-layer desktop baseboard designs to 10- layer or more server baseboard designs. Guidelines and constraints in this document are intended for use on both baseboard and add-in card PCB designs. This includes interconnects between PCI Express devices located on the same baseboard (chip-to-chip routing) and interconnects between a PCI Express device located “down” on the baseboard and a device located “up” on an add-in card attached through a connector. This document is intended to cover all major components of the physical interconnect including design guidelines for the PCB traces, vias and AC coupling capacitors, as well as add-in card edge-finger and connector considerations. The intent of the guidelines and examples is to help ensure that good high-speed signal design practices are used and that the timing/jitter and loss/attenuation budgets can also be met from end-to-end across the PCI Express interconnect. However, while general physical guidelines and suggestions are given, they may not necessarily guarantee adequate performance of the interconnect for all layouts and implementations. Therefore, designers should consider modeling and simulation of the interconnect in order to ensure compliance to all applicable specifications. The document is composed of two main sections. The first section provides an overview of general topology and interconnect guidelines. The second section concentrates on physical layout constraints where bulleted items at the beginning of a topic highlight important constraints, while the narrative that follows offers additional insight.
上传时间: 2013-10-15
上传用户:busterman
Abstract: Electrolytic capacitors are notorious for short lifetimes in high-temperature applications such asLED light bulbs. The careful selection of these devices with proper interpretation of their specifications isessential to ensure that they do not compromise the life of the end product. This application notediscusses this problem with electrolytic capacitors in LED light bulbs and provides an analysis that showshow it is possible to use electrolytics in such products.
上传时间: 2013-11-17
上传用户:asdfasdfd
Abstract: There are differences between the operation of low-frequency AC transformers and electronic transformersthat supply current to MR16 lamps, and there are also differences in the current draw for MR16 halogen lamps andMR16 LED lamps. These contrasts typically prevent an MR16 LED lamp from operating with most electronictransformers. This article explains how a high-brightness (HB) LED driver optimized for MR16 lamps will allow LEDlamps to be compatible with most electronic transformers.A similar version of this article appeared on Display Plus, July 7, 2012 and in German in Elektronikpraxis, October 1,2012.
上传时间: 2013-10-14
上传用户:playboys0
Abstract: This application note details a step-by-step design process for the MAX16833 high-voltagehigh-brightness LED driver. This process can speed up prototyping and increase the chance for firstpass
上传时间: 2013-10-09
上传用户:tianjinfan
We provide complete power solutions with a full lineup of power managementproducts. This brochure provides an overview of our high performance DC/DC switching regulatorcontrollers for applications including datacom, telecom, industrial, automotive, medical, avionicsand control systems. We make power design easier with our industry-leading field applicationengineering support; a broad selection of demonstration boards with schematics, layout filesand parts lists; SwitcherCAD® software for simulation, application notes and comprehensivetechnical documentation.
上传时间: 2013-10-15
上传用户:lz4v4
In industrial applications, high voltage power supply spikes with durations ranging from a few microseconds to hundreds of millisecondsare commonly encountered. The electronics in these systems must not only survive transient voltage spikes, but in many cases alsooperate reliably throughout the event.
上传时间: 2013-11-07
上传用户:redmoons
Linear Technology’s high performance battery management ICsenable long battery life and run time, while providing precision charging control, constantstatus monitoring and stringent battery protection. Our proprietary design techniques seamlesslymanage multiple input sources while providing small solution footprints, faster charging and100% standalone operation. Battery and circuit protection features enable improved thermalperformance and high reliability operation.
上传时间: 2013-10-13
上传用户:yyq123456789
Abstract: This document details the Lakewood (MAXREFDES7#) subsystem reference design, a 3.3V input, ±12V (±15V) output, isolated power supply. The Lakewood reference design includes a 3W primary-side transformer H-bridge driver for isolated supplies, and two wide input range and adjustable output low-dropout linear regulators (LDOs). Test results and hardware files are included.
标签: MAXREFDES Lakewood Isolated Output
上传时间: 2013-11-02
上传用户:fengzimili