化镍浸金工艺之黑盘特征、测试方法介绍及判定标准建议

刚挠结合板是一种兼具刚性PCB的稳定性和FPC的柔软性的新型印刷电路板,其对恶劣应用环境具有很强的抵抗力,有较好的信号传输通路,并可实现不同装配条件下的三维立体组装,因此在医疗与军事设备和通讯方面有重要的应用,我国的线路板制造企业也正在逐步提高软硬结合板占总体产量的比例。软硬结合板因为材料特性与产品规格的差异,在设备的适用程度上将影响产品良率与稳定度,因此跨入软硬结合板的生产前须先考虑到设备的适用程度;为验证我公司的硬板设备制作软板的可行性,选取一款刚挠结合板作为样品试制作。     

刚挠结合板制作中难点改良

刚挠结合板兼具刚性PCB的稳定性和挠性PCB的可弯曲性,发展前景十分可观.本文主要介绍了刚挠结合板在刚性PCB制作过程中出现的制作难点以及改良经验,以供同行业参考. 1 制作基本流程(图1) 2 关键工序与改良 2.1 刚挠结合板制作信息 排板结构:25 (H/H) 1080 1(H/H) 1080 25 (H/H)(图2) 半固化片:1080=0.074 mm (2.9 mil)生益No-Flow PP RC:64％ 2.2 制作中的重点难点 软板部分:软板刚性设备制作,压制PI覆盖膜,PI膜压合; 硬板部分:硬板Core与PP的窗口制作,刚挠结合压板涨缩、溢胶量控制等.     

挠性板部分埋入制作刚挠结合板

介绍了一种刚挠结合板制作新技术,只在需要弯折的部位埋入挠性板,通过挠性板使各刚性板之间实现互连。详细分析了设计与材料对刚挠结合板的影响,研究了预压合保护膜、挠性板埋入层压等关键工艺,给出了工艺难点的具体解决办法。结果表明,该技术提高了挠性板材的使用率,简化了挠性板及刚挠结合板加工工艺,使刚挠结合板成品率提高至少8%。     

刚挠结合板层压分层研究

随着刚挠结合板的应用范围越来越广泛,对刚挠结合产品可靠性的要求也越来越高,而刚挠结合板制作的重点主要是保证刚性板部分与挠性板部分通过层压使之结合在一起后的可靠性,如何保证其可靠性,使之不会出现分层问题,是加工刚挠结合板的最大难点。文章分析了影响刚挠结合板层压分层的关键结构因素和工艺方法,并通过因素分析、试验验证,制定出层压加工方案,提升了刚挠结合产品的层压可靠性。     

浅淡刚挠结合多层板的工程制作

刚挠结合板具备挠性与刚性PCB两者特性,文章就刚挠结合多层板在工程设计、资料制作过程中所应注意的问题,做了一个粗略的总结,希望对同行的朋友们有所启发和帮助。     

一种覆盖膜开窗的刚挠结合板制作方法

随着电子技术的不断发展,在某些特定的领域,普通的刚性PCB已很难满足产品对其特殊的组装要求,刚挠结合板以其优异的三维挠曲性正获得越来越广泛的应用。本文介绍了一种覆盖膜开窗的刚挠结合板制作方法,通过两次压合和两次机械刻槽的方式可成功制作出品质、性能优异的刚挠结合板。     

18层背板型刚挠结合板制作技术介绍

大型工控设备等领域通常需要用到尺寸较大PCB,刚挠结合板也不例外,高厚度和大尺寸对此类刚挠结合板制作提出了新的技术要求。文章介绍了一款18层(5R+6F+7R)、200mm×700mm刚挠结合板层偏控制、软板区域成型等技术,为大尺寸高多层刚挠结合板制作提供技术依据。     

刚挠结合板阻抗设计研究

随着数据传输速率越来越快,刚挠结合板的阻抗要求也越来越高,而刚挠结合板和普通刚性板的阻抗有很大区别,这对刚挠结合板的阻抗设计和控制带来很大的挑战,其阻抗设计值与理论值差别较大,往往实际测值超出理论值范围,达不到客户要求。针对如何满足客户刚挠结合板成品阻抗要求从工程设计方面进行探讨,希望能对PCB制造业同行有所帮助。     

十六层刚挠结合板制作体会

本文讨论了多层刚挠结合板在制作过程中所遇到的难题和对应的解决办法,以十六层刚挠结合板的制作为范例,突出了制作过程中的难点及控制技巧,为同行各企业提高生产多层刚挠结合板的技术水平起到抛砖引玉的作用。     

外层挠性结构的刚挠结合板线路制作探讨

文章着重讲述在刚挠结合板制作过程中,外层为挠板结构设计的刚挠结合板线路及通孔铜厚的实现方法,以及制作过程中制作难点和易产生缺陷的解决途径。     

Shedding light on device crowding: custom lighting assemblies savespace in hard-drive designs

A PC manufacturer, in search of the best status lighting arrangement for its new hard drive, has custom designed a lighting assembly. To save valuable space near the front of the hard drive, a group of three display lights was separated from the light source. The source, three surface-mount LEDs attached to a circuit board, was placed behind the hard drive. To deliver the light to the front of the device, an assembly consisting of flexible fiber-optic strands with rigid polycarbonate light pipes at both ends was employed     

一种高导热三维铝基印制板制作方法的研究

铝基板是一种最常见的金属基覆铜板,因其具有良好的导热性、电气绝缘性和尺寸稳定性,目前已被广泛应用。文章通过对铝基印制后续装配机理及过程的分析,从提高散热性能及减少装配空间的角度出发,进行了大胆的尝试,将承载印制板的机箱与印制板合二为一,产品实现了线路板与机箱的高度集成,取得了散热效果良好,缩小产品体积的目的。     

浅述精密微振动电机用整流子板的制作

随着发达市场和发展中市场对高端的彩屏手机和拍照手机的需求,作为多功能手机必需的元器件——双面振动电机整流子线路板的需求量也保持了强劲的增长。预计这种增长的势头将会在未来的几年里继续保持。所以我公司在现有设备的基础上研制开发整流子线路板有着重要的意义,必将为企业股东和员工带来丰厚的回报。文章主要介绍了振动整流子线路板的工艺制作流程和前景。     

Smart tooling for assembly of thin flexible systems

Emerging electronic assemblies are demanding lower cost, lighter weight, miniaturized packages mounted on thin flexible circuit boards and/or flex circuits. However, the compliant nature of the flex substrates poses new processing technology challenges for standard surface mount assembly equipment. A particular challenge is fixture tooling. The flexible substrate experiences significant transverse displacements under perpendicular assembly and/or fixturing forces during solder paste printing and component placement processes. The transverse displacements result in misregistration of the component leads and substrate bond pads, leading to severe assembly process defects. The solder reflow process further complicates the issue due to the thermo-mechanical warpage induced. Conventional assembly equipment utilizes dedicated tooling designed to handle rigid circuit board assemblies. As electronic assemblies move toward very fine pitch surface mount packages, chip scale packages, and flip chip attachment assembled to thin flexible double-sided circuit boards, reengineered and specialized dedicated tooling for fixturing flexible substrates in standard assembly equipment are becoming extremely important. This paper focuses on developing analysis methodologies and theories for implementing machine dedicated Smart Tooling. The primary goals being to determine the impact of fixturing on assembly process quality and to determine optimum fixturing configurations for thin flexible circuit board assemblies based on circuit design data. A mathematical model to describe both transverse and perpendicular displacements of flex substrates is developed, and its closed form solution for transverse displacements is obtained. Fixturing configurations based on a perimeter support technique of flex substrates is analyzed to minimize transverse displacements     

集成电路可制造性工程与设计方法学

集成电路可制造性工怀设计是近年来发展很快的研究领域，它集ＩＣ设计、制造、封装和测试过程为一体，在统一框图（即产品制造成本和成品率驱动下）下，对产品进行规划和设计，应用该设计可以大大缩短ＩＣ产品研制周期，降低制造成本，提高成品率和可靠性，本文将综述该领域的研究进展，并阐述进一步的研究方向。     

Field reworkable underfill materials for flip chip on boardassemblies

Studies have shown that underfill encapsulation dramatically improves the solder joint fatigue reliability of flip chip on board (FCOB) assemblies. The lack of reworkability of the underfill after the product is in the field has limited the integration of FCOB into cost sensitive electronic products and the continued proliferation of the FCOB technology will depend on the development of reworkable underfill materials systems. This paper presents data that correlates reliability performance to mechanical properties for twelve field reworkable underfill materials from three different suppliers. Their respective properties, processing parameters, and reliability performances are compared to the qualified, commercially available high performance underfills. Techniques were developed to redress the printed wiring board (PWB) site to enhance the reworked FCOB assembly yield. In addition, reliability performance results and failure analysis observations were compared to the first time nonreworked assemblies     

高厚度铝基板的工艺加工

高厚度铝基板是一种特殊印制板,其具有良好的尺寸稳定性和导热性,逐渐被应用于军用设备和高科技民品领域,文章对高厚度铝基板的加工工艺进行了探讨,并对生产过程存在的问题进行分析并找出改进措施。     

Low cost bumping by stencil printing: process qualification for 200 μm pitch

Area array packages (flip chip, CSP (Chip scale packages) and BGA) require the formation of bumps for the board assembly. Since the established bumping methods need expensive equipment and/or are limited by the throughput, minimal pitch and yield, the industry is currently searching for new and lower cost bumping approaches. The experimental work of stencil printing to create solder bumps for flip chip devices is described in detail in this article. In the first part of this article, a low cost wafer bumping process for flip chip applications will be studied in particular. The process is based on an electroless nickel under bump metallization and solder bumping by stencil printing. The experimental results for this technology will be presented, and the limits concerning pitch, stencil design, reproducibility and bump height will be discussed in detail. In the second part, a comparison of measured standard deviations of bump heights as well as the quality demands for ultrafine pitch flip chip assembly are shown.     

影响板级质量的多种因素

组装工艺通常是板级产品最关键工艺,SMT将印制板和元器件通过SMT设备组装到一起。如果测试不通过,客户只归罪于最终的组装加工厂,其实影响板级产品质量的不光是组装加工,还有元器件质量、印制板质量以及加工工艺等。通过对一个案例的金相分析,介绍影响板级质量的多种因素和这些因素是如何影响产品质量的。