大管脚数的表面安装塑封器件新的失效机理的研究

本文简述了塑封器件的特点及其发展，和随之而出现的新的失效机理，塑封分层剥离，开裂（俗称“爆米花”效应）。并通过对一个ＱＦＰ８０脚表面安装（ＳＭＤ）塑封器件微处理单元电路的失效分析，使用先进的手段证实了大管脚表面安装塑封器件管壳的分层剥离产生的应力可使键合接头开裂，导致器件电失效，及塑封分层剥离，开裂产生的原因，提出了避免此类现象发生的合理建议。     

塑封集成电路离层对可靠性的影响及解决方法

塑封集成电路因其是非气密性封装,封装材料热膨胀系数的不同以及被粘接材料表面能低,是造成塑封电路离层或开裂的内部原因。通过选择特殊的封装材料（特别是框架材料）和工艺可以解决离层或开裂问题,大大提高塑封集成电路的稳定性和可靠性。水汽是造成塑封集成电路离层或开裂的外部原因,可以通过驱除和防潮措施来解决。要提升塑封集成电路可靠性,必须从技术和工艺上解决塑封电路离层或开裂问题。我们在这方面做了有益的尝试,取得了良好的效果,为拓展塑封集成电路的应用领域创造了条件。     

集成电路封装开裂产生原因分析及对策

塑封体开裂是集成电路封装影响产品可靠性的致命不良,具有产品损失大、不易发现、隐患时间长等特点。本文探讨在制造过程中的开裂预防与控制方法。     

塑封倒装焊焊点开裂分析及改善研究

随着科技的发展,半导体元器件小型化、高性能、轻量化的需求日益迫切,塑封倒装焊技术得到了广泛应用。因为基板的易形变性及各封装材料间的热膨胀系数不匹配,焊点开裂成为影响封装可靠性的重要因素之一。为了研究倒装焊产品在封装制程中焊点开裂的失效原因,利用有限元分析（ANSYS）软件建立倒装焊塑封封装体有限元模型,模拟回流焊过程中的塑封基板形变与凸点应力分布,并分析焊点开裂失效的原因。结果表明,在回流焊过程中,基板形变量大于裸芯,外围凸点倾斜较大,承受的应力及应变能最大,外沿凸点为最易失效点,采用加载具作业可显著降低失效风险。     

塑封微电子器件失效机理研究进展

塑封器件在现在的封装产业中具有无可比拟的优势,相关研究引起了人们广泛关注.简要介绍了塑封微电子器件的发展史,以及国内外塑封器件可靠性的研究现状.对塑封器件的主要失效机理研究进展进行深入探讨,如腐蚀、分层、开裂等,提出了几种提高塑封器件可靠性的措施.论述了用于塑封器件质量评估的试验方法,并展望了塑封器件在军工领域的潜在应用前景.     

粘片胶固化对塑封集成电路可靠性的影响

当具有诸如分层等可靠性缺陷的微电子器件焊接在线路板上,通过回流焊时会产生塑封体裂缝、塑封体鼓胀等重要缺陷。粘片胶未充分固化、水汽未完全排除、环境湿气较大易吸湿等原因导致水汽沿着塑封体与引线引脚向内部扩散。表现为各结合面的分层,粘片胶与芯片之间、塑封体与引线之间、塑封体与芯片之间,各种分层在快速加热产生的热应力下水汽快速膨胀,从而引起器件可靠性隐患。     

JQX-72F小型大功率电磁继电器

JQX-72F继电器具有体积小、耐压高、切换能力强、安装方便、塑封型封装型式等特点。介绍该产品的原理、结构、技术性能参数。     

引线框架塑封集成电路冲切过程中的检测和防护

在引线框架塑封集成电路的引线冲切成型过程中,存在塑封体破裂脱落、引脚折断等异常现象,如果不能及时发现这些异常,就会造成产品的批量报废或相关成型模具损坏的情况.介绍了如何使用光电传感器和检测针系统对集成电路引脚冲切成型中可能出现的异常进行有效监测和防护.     

球栅阵列——更适合多端子LSI的表面安装式封装

塑封球栅阵列（ＢＧＡ）是一种新型表面安装多端子型ＬＳＩ封装。与塑封四方扁平封装（ＱＦＰ）相比，前者外形更小，设备与操作较为简单，可靠性也有所提高。ＢＧＡ替代ＱＦＰ的尝试从美国开始，并正在各国展开     

球栅阵列——更适合多端子LSI的表面安装式封装

塑封球栅列（ＢＧＡ）是一各新型表面安装多端子型ＬＳＩ封装。与塑封四方扁平封装（ＱＦＰ）相比，前者外形更小，设备与操作较为简单可靠性民提高。ＢＧＡ替代ＱＦＰ的尝试从美国开始，并正在各国展开。     

Molding compound trends in a denser packaging world: qualificationtests and reliability concerns

This work benchmarks the current reliability tests used by the electronics industry, examines those tests that affect and are affected by molding compounds, discusses the relevance of accelerated testing, and addresses the major reliability issues facing current molding compound development efforts. Six compound-related reliability concerns were selected: moldability; package stresses; package cracking; halogen-induced intermetallic growth at bond pads; moisture-induced corrosion; and interfacial delamination. Causes of each failure type are surveyed and remedies are recommended     

Use of C-SAM acoustical microscopy in package evaluations and failure analysis

Acoustical microscopy is gaining wide acceptance in the microelectronic packaging community. C-mode scanning acoustical microscopy, C-SAM, is widely used in package evaluations and for failure analysis. This paper discusses several specific topics. These include: (1) popcorn cracking in SMDs; (2) an evaluation of solder die attach in power packages; (3) an instance of top of die delamination which resulted in electrical failures; and (4) moisture sensitivity of other surface mount power packages and how it resulted in ball bond degradation during a new product qualification.     

Isothermal aging effects on flex cracking of multilayer ceramic capacitors with standard and flexible terminations

Multilayer ceramic capacitors (MLCCs) are known to experience flex cracking when subjected to bending stresses. An experimental study was conducted to determine the susceptibility to flex cracking of flexible- and standard-termination surface mount MLCCs assembled with lead-free or tin–lead solders and aged at two different temperatures for 200 h. Experimental results showed that MLCCs mounted on printed circuit boards with lead-free solder are less susceptible to flex cracking compared with MLCCs mounted on boards with eutectic tin–lead solder. Two factors which make capacitors assembled with lead-free solder less susceptible to flex cracking were discussed: the lower tensile stresses inside the capacitor body which are a result of the differing elastic–plastic mechanical properties of the solder, and the higher residual compressive stresses after solder reflow assembly which are a result of the higher solidification temperature for the Sn3.0Ag0.5Cu lead-free solder. Flexible-termination MLCCs showed much more resistance to flex cracking in comparison to standard-termination MLCCs assembled with both lead-free and tin–lead solders. Aging at elevated temperatures had little effect on flex cracking susceptibility of MLCCs assembled with tin–lead solder. For MLCCs assembled with lead-free solder, aging at 150 °C increased the susceptibility to flex cracking in comparison with un-aged MLCCs.     

SMT焊接缺陷研究

当今,作为主要的电子装联技术,表面组装技术得到了长足的发展。表面组装产品由于在成本、质量和可靠性等方面具有相当的优势,使其受到广大用户的青睐。虽然表面组装技术和表面组装产品具有无可比拟的优势,但是表面组装技术涉及的因素众多,包括器件、材料、设备和工艺等,这导致表面组装过程中容易出现焊接缺陷。焊接缺陷严重影响表面组装产品的质量和可靠性,对其应进行深入的研究。本文探讨了在表面贴装过程中的焊接缺陷类型,它们的检测判据,分析了它们产生的主要原因及危害,并提出了相应的预防处理措施。     

表面贴装技术的新发展

自20世纪80年代以来,表面贴装技术已在电子工业中得到了广泛的应用和发展。本文从SMT设备、表面安装电路基板、表面安装元件、辅助材料、生产线管理等五个方面对其未来的发展趋势作了初步分析。     

表面安装技术与表面安装元件发展面面观

本文综合性地介绍了国内外表面安装技术与表面安装元件的发展现状、技术水平、市场动向,以及今后尚需开发的主要课题。     

Assessing the performance of crack detection tests for solder joints

This paper presents both modelling and experimental test data to characterise the performance of four non-destructive tests. The focus is on determining the presence and rough magnitude of thermal fatigue cracks within the solder joints for a surface mount resistor on a strip of FR4 PCB. The tests all operate by applying mechanical loads to the PCB and monitoring the strain response at the top of the resistor. The modelling results show that of the four tests investigated, three are sensitive to the presence of a crack in the joint and its magnitude. Hence these tests show promise in being able to detect cracking caused by accelerated testing. The experimental data supports these results although more validation is required.     

SMT柔性制造技术研究

对电子电路表面组装生产的柔性比问题进行了分析研究，提出了利用现有组装设备形成电子电路表面组装柔性制造系统的设计思想，并对其中的系统组成，信息集成，质量保证体系的形成等关键问题进行了探讨。     

片式电感器现状、技术与市场

概述了片式电感器现状,着重介绍了片式电感器制造技术与市场。     

表面组装工艺系统可靠性研究

文章提出了表面组装工艺系统可靠性的概念,介绍了工艺系统可靠性指标,提出了表面组装工艺系统可靠性建模方法。