边界扫描技术及其在电路板级测试应用

介绍了边界扫描测试技术的基本原理,提出了边界扫描技术的板级测试策略和整体测试流程,并对扫描链路设计中的具体问题进行分析,最后结合可测试性设计提出了电路板设计时应遵循的原则.     

用FPGA实现RFID板级标签的设计

制作板级标签对UHF频段的RFID系统设计有着特殊意义,尤其在标签防冲突方面很有作用。文章首先介绍了板级标签的硬件组成及其工作原理,然后分析了电子标签数字处理部分的组成和实现,最后给出了板级标签的设计和测试结果。     

一种简易去除PCBA板工艺边工装

文章介绍了一种简单的去除PCBA板工艺边工装的设计原理,该工装可快速可靠地裁切各种大小并预刻有V型槽的PCB板,希望对相关工程设计人员有所帮助。     

基于LabVIEW的变桨控制器板级测试平台设计

基于虚拟仪器技术,研究了变桨控制器板级测试平台的测试原理、下位机程序的设计,提出了一种采用状态机与事件结构相结合的分层设计方法用以提高上位机LabVIEW程序的开发效率,最后针对每项测试任务,采用分多次测试的方法实现了板级测试软件。该板级测试软件已获得实际应用并验证了按照本文方法设计的板级测试软件在变桨控制器的板级测试中具备效率高、准确性高的优点。     

板级备件通用测试系统设计

针对板级备件种类的多样性,采用统一总线接口并实现总线的可配置的方法设计了一种通用测试系统.在硬件连接达到统一的情况下,总线仿真板可以通过编程实现需要的总线形式,达到测试多种型号板级备件的目的.介绍设计思路及系统组成,并通过实例分析了测试过程.该系统具有良好的可扩展性,能满足多种板级备件的测试需要.     

一种安全计算机板级测试系统的设计与实现

针对铁路安全计算机,根据板级测试的基本原则,结合计算机辅助测试技术,构建安全计算机板级测试平台,解决了电源可靠受控,测试激励信号控制的问题,根据主要的板级软件测试流程,设计并实现了综合板级测试系统。该系统已获得实际应用,实践证明该系统稳定可靠,可以实现对多类型板级测试的目的,并且有效检测出电路设计中的错误,大大提高了产品出厂的测试效率。     

大型空间遥感器动力学试验

大型空间遥感器结构复杂、重量大,在研制过程中,给地面动力学环境试验工装的设计带来很大的困难.振动工装是振动试验的传力部件,将振动台与遥感器连接起来,其性能直接影响到振动试验的真实程度和可靠程度.本文论述了遥感器振动工装研制及动力学试验过程.正弦振动和随机振动结果表明,振动台的振动输入条件与工装对遥感器的输入条件基本一致...     

Team center/NX集成下的工装快速设计系统设计及应用

本文针对现代工装设计过程中出现的问题,有效提高工装数据管理的有效性,本文就设计了基于Team center/NX的工装快速设计系统.首先实现工装系统模型设计的介绍,研究数据存储、管理及交互的集成功能介绍.之后对工装系统的设计进行了全面的介绍,包括辅助设计、变形设计等.最后全面分析工装设计的效率.通过研究表示,本文所设计的工装快速设计系统比传统的工装设计系统的效率有进一步的提高.     

短波宽带低压功率放大器的设计与实现

对设计的低压宽带功放的指标进行了介绍,并对设计功放所涉及的理论进行研究和讨论,在对所选用的功放管在厂家没有提供s参数的情况下进行了相关单管测试和验证,给出了参数优化后结果,根据分析以及计算后对功率放大器进行设计,时功率放大器做了硬件设计调试,并给出板级相关指标的测试结果。结果表明,该设计符合要求。     

防静电技术讲座12——实用静电防护工艺

1.4 防静电工装板垫电子产品组装流水线体的传动面(又称工作面、测试面)上都配备了一种“缓冲弹性橡胶板”,工程中习惯叫工装板垫,由于生产过程中的摩擦、传动、感应等多种因素易产生高压静电,直接导致产品中静敏器件的损坏,因此要求生产线上安装防静电工装板垫,不可使用普通橡胶垫的工装板做传动面。防静电工装板垫的一般要求 a.具有良好的扩散与泄漏静电的能力。     

航天用刚挠印制板可靠性研究

通过分析影响航天用刚挠印制板可靠性的主要因素分层和金属化孔的质量,从刚挠印制板的设计、工艺控制等角度提出适合于航天用刚挠印制板的材料、关键工序工艺条件以及特殊检验要求。通过振动试验、加速度试验、加严热冲击试验、焊接后高低温循环试验等试验证明了高可靠性刚挠印制板可以应用于航天器产品,并给出航天用刚挠印制板具体的材料、生产工艺及关键工艺参数建议。     

Shock impact reliability characterization of a handheld product in accelerated tests and use environment

The effect of mechanical shock impacts is a key factor in the reliability of modern handheld products. Due to differences in product enclosures, impact orientations, strike surfaces and mountings of component boards, the loading conditions induced in a true product drop differ from those encountered in standardized board-level tests. In order to better understand the correlation between board-level drop testing and actual drops of a complete device, series of board and product-level drop tests were conducted using specialized test boards.The mechanical shock impact response of the commercial handheld device component board was characterized with the help of acoustic excitation laser vibrometry and finite element analysis. The results were used to design the mechanically compatible specialized test board for both 4-point supported board-level and unsupported product-level drop tests. Special care was taken to ensure that the vibration behavior of the test board accurately represented the vibration behavior of the commercial component board. Additional board-level drop tests were conducted using a JEDEC JESD22-B111 compliant component board for comparison.The drop test results showed that, even though the test board design and supporting method have a marked influence on the strain conditions and lifetime of solder interconnections, the primary failure mode and mechanism under the product-level drop tests is comparable to that typically encountered in the standard JEDEC JESD22-B111 board-level drop tests. More detailed analyses suggest that the comparability of the shock impact loading conditions affecting solder interconnections can be characterized using three metrics: (1) the maximum component board strain rate, (2) the maximum board strain amplitude and (3) the damping of the component board.     

电路板焊点在工程环境条件下寿命分析

在电子设备寿命周期中．要经历各种环境载荷。我们需要综合号虑载荷对电子设备可靠性和寿命的影响。在该文中．以一块电路板为案例。建立整板模型．然后设定边界、分别加载温度和随机振动载荷。并利用有限元分析工具ANSYS计算,得出应力应变云值。最后基于Coffin—Manson疲劳寿命模型和线性叠加模型,分析和预测热循环和随机振动条件下．器件焊点疲劳寿命,为整板器件可靠性设计提供参考,     

Design of Experiments for Board-Level Solder Joint Reliability of PBGA Package Under Various Manufacturing and Multiple Environmental Loading Conditions

A design of experiments was conducted to determine the reliability of plastic ball grid array packages under various manufacturing and multiple environmental loading conditions. Parameters included conformal coating methods, underfill, solder mask defined, and non-solder mask defined pads. Board-level temperature cycling, vibration, and combined temperature cycling and vibration testing were performed to quantify the reliability and identify preferred design parameters. Through the main effects and interaction analysis, test results show underfill is the key parameter related to the solder joint reliability improvement. Conformal coat method and printed circuit board pad design are not main effects on solder joint reliability. No interactive relationship exists among these three factors under temperature cycling loading, but some interactive relationship between printed circuit board pad type and the conformal coating method exists under vibration and combined loading conditions.     

有源安装板振动试验研究

工作中的有源安装板处于振动状态,剧烈的振动会导致有源安装板结构的破坏,缩短有源安装板使用寿命,因此对有源安装板进行振动试验研究具有重要意义。文中针对某雷达有源安装板进行了振动试验,得到了X、Y、Z这3方向第一次与最后一次试验后的特征级曲线对比图,并最终分析了试验结果,且对有源安装板的结构设计进行了评估试验。     

板级电路模块振动结构优化技术研究

以特定板级电路模块为研究对象,建立有限元模型.运用ANSYS分析软件对影响板级电路固有频率的主要结构参数进行灵敏度分析,从而得到各设计参数和板级电路模块一阶固有频率的关系.然后以灵敏度分析为理论依据进行结构优化设计,在优化过程中,目标参数逐步逼近于最优解,每一步优化设计变量求取新的灵敏度来确定搜索方法,然后进一步优化,从而使设计参数能很快达到最优解或较优化解.     

板载FPGA芯片的边界扫描测试设计

边界扫描技术是标准化的可测试性设计技术，它提供了埘电路板上器件的功能、互连及相互问影响进行测试的一类方法，极大地方便了对于复杂电路的测试。文中针对某设备分机具体的待测电路，遵循IEEE1149.1标准，结合FPGA芯片的BSDL文件进行边界扫描测试设计，理解和掌握其设计原理、数据结构，并实现板级测试与ATE的接口。     

Advanced analysis on board trace reliability of WLCSP under drop impact

Through an aggressive product development program which includes experiment and simulation, Amkor has developed the next level of WLCSP (CSP^nl™), a product which exhibits superior board level reliability when subjected to drop impact, a strong requirement for portable electronics. Failure mechanism of WLCSP under drop test has been established. Depending on type of WLCSP and test board design, three primary failure modes can be observed, i.e. copper (Cu) board trace crack, Cu RDL (redistribution layer) vertical crack and Cu/Under Bump Metallization (UBM) delamination. CSP^nl can exhibit distinct failure modes under different test board and/or CSP^nl designs, resulting in a vast difference in drop test lifetimes. The primary failure mode is shifted whenever the weakest link is removed through design improvement. This paper will focus on detailed analysis of copper board trace crack under drop test, using an integrated approach of testing, failure analysis, material characterization and modeling. Board design guidelines are formulated to understand the effects of I/O position, board trace routing direction, board trace width, tear drop design, PCB pad size, stack-up thickness, and alloy materials on board trace reliability. Comparison is also made on possible impact on Cu RDL reliability.     

Module packaging effects on MEMS airbag sensor performance for automobiles

In this paper, the effects of the packaging module housing of MEMS airbag sensor for signal generation is studied. Conventional airbag sensor packaging module for automobiles is composed of the accelerometer MEMS sensor mounted on a printed circuit board, which is assembled inside a plastic housing. And the entire module is mechanically installed by bolts on the automobile frame structure to capture the acceleration from the structure vibration. In this case, the signal path from the frame to the sensor is complex, and the frame vibration is interacted with the module vibration, which may delay and distort the original signal pattern. To remove housing vibration effects, a new sensor packaging on the flexible circuit board was introduced to attach directly on the frame structure surface using adhesive. For the signal characterization, impact tests were performed for the conventional sensor packaging and the directly attached sensor using an aluminum channel and automobile side frame. Numerical analyses were also carried out to understand the vibration effects of the packaging module and the structure. It was found that the vibration behaviors of the frame structure and the module housing, and the module installation location had significant influence on the impact signal generations. The results indicated that the design of the airbag sensor packaging system for proper airbag explosion requires comprehensive engineering considerations.     

微米级平行互连线的测试结构设计

研究分析无串扰传输理想模型的条件,根据高速高密度电路板中微米级、亚毫米级互连线电磁串扰特性研究需要,首次提出微米级平行互连线的测试结构设计。经射频电路理论分析推导了测试结构对系统串扰没有影响。构建了有、无测试结构的微米级平行互连线物理模型,仿真分析后,加工制作有测试结构的微米级平行互连线电路板。研究结果表明,当数字基带信号传输频率在0~3 GHz 范围时,无测试结构仿真电路模型、有测试结构仿真电路模型、有测试结构的实验电路板,三者串扰特性吻合;微米级平行互连线的测试结构设计合理,具有工程参 考价值。