表面组装焊点可靠性分析研究

通过实际ＳＭＴ混装组件印制板，介绍环境应力筛选试验的情况和结果，对其失效原因进行了分析与总结，同时进行ＳＭＴ焊点可靠性评估与组件产品失效预测，初步验证了焊点的可靠性。     

用环境应力筛选试验研究SMT焊点可靠性的探讨

本文结合实际SMT混装组件制，阐述SMT混装组件失效的机理，介绍了环境应力筛选试验的情况和结果，对影响可靠性的各种因素进行了分析与总结，提出了提高可靠性的措施，指出了环境应力筛选是保证SMT混装组件产品可靠性的必要工作手段，它可排除早期故障、使产品可靠性接近设计的固有可靠性水平。     

用环境应力筛选试验研究SMT焊点可靠性的探讨

本结合实际SMT混装组件制，阐述了SMT混装组件失效的机理，介绍了环境应力筛选试验的情况和结果，对影响可靠性的各种因素进行了分析与总结，提出了提高可靠性的措施，指出了环境应力筛选是保证SMT混装组件产品可靠性的必要工作手段，它可排除早期故障、使产品可靠性接近设计的固有可靠性水平。     

SMT波峰焊接的工艺研究

对ＳＭＴ焊接中的焊点内在质量，焊点显微组织，以焊接工艺参数对焊接显微组织与焊接强度的影响进行了初步的研究与探讨；同时对ＳＭＴ混装波峰焊接最佳工艺流进行了较为深入地工艺试验，提出了焊接整体质量与最佳ＳＭＴ混装波峰焊接的实用工艺。     

SMT混装波峰焊接的质量与工艺控制研究

就ＳＭＴ电路板混装波峰焊接生产中的工艺与质量控制进行讨论,阐述了混装工艺与焊接质量过程控制的要点,提出了工艺问题的解决方法。     

产品老炼,环境应力筛选,可靠性保证试验评价

产品开发生产的工艺过程少不了老炼或环境应力筛选，以便暴露和消除早期失效，定量环境应力筛选比老炼的效率高得多，是最先进的可靠性工程试验。可靠性保证试验用于验证产品早期失效是否消除，还可以保证产品达到规定的最低的ＭＴＢＦ值。     

环境应力筛选方法及效果评估

从环境应力筛选的概念出发，以某研制的组件为例，介绍了环境应力筛选的目的、方法以及筛选效果的评估，证实环境应力筛选是保证电子产品可靠性实现的重要环节。列举了环境应力筛选的注意事项。     

封面介绍

封面介绍Ｓ、Ｃ波段相控阵Ｔ／Ｒ组件Ｓ、Ｃ波段相控阵Ｔ／Ｒ组件，采用ＭＭＩＣ芯片和小型化ＭＩＣ电路混合形式，运用微组装工艺制作而成。其中ＬＮＡ，ＳＰＤＴ等使用了５片ＭＭＩＣ芯片；限幅器、移相器等电路则采用二极管芯片组装完成。功率放大器输出级是大功率ＦＥ...     

SMT与COB技术在无线寻呼机中的开发应用

表面贴装技术（ＳＭＴ）和板载芯片技术（ＣＯＢ）在当今且装中起着愈来愈重要的作用。从工艺方案的确定至具体工艺实施，对ＳＭＴ及ＣＯＢ混装工艺在无线寻呼机生产中的应用开发作了介绍，最后阐述了功能测试架的设制。     

环境应力筛选与产品可靠性

本文论述了环境应力筛选（ＥＳＳ）的原理及其对提高产品可靠性的作用，并简要介绍了美国三军ＥＳＳ规范和国家军标ＧＪＢ１０３２《电子产品环境应力筛选方法》及国外用于实施ＥＳＳ的设备情况。     

有铅无铅高密度混装工艺技术研究

随着电子产品无铅化的不断推进,在高可靠电子产品组装中,采用有铅焊料焊接有铅无铅镀层器件并存的情况不可避免。因此混合焊接工艺和焊点的可靠性是研究的重点。本文提出了有铅无铅高密度混装工艺研究方法,针对有铅无铅镀层兼容性、高密度混装再流焊工艺、及有铅无铅高密度混装焊点可靠性开展技术研究工作,并与同行业者分享阶段性研究成果。     

A 2-level environmental-stress-screening (ESS) model: amixed-distribution approach

Environmental stress screening (ESS) is used to reduce, if not eliminate, the occurrence of some types of failures from the field by fixing them before the product is deployed. This paper models a 2-level ESS program where screening is performed at the part and unit levels. The parts are screened for a specified duration before being assembled into a unit. Defects induced during the assembly process are screened at the unit level. These parts and connections are assumed to come from either a good or a substandard population, and their times-to-failure distributions are modeled by mixed distributions. The optimal screening durations are obtained by minimizing the life-cycle cost. The model is simple to use and its viability is illustrated using mixed exponential distributions. The implementation of screens at various levels depends on costs and failure distribution characteristics     

Planning of Production Reliability Stress-Screening Programs

This paper describes qualitative and quantitative techniques for planning, monitoring, and evaluating stress screening programs. The techniques were developed under a recent study for the Rome Air Development Center. A model for use by reliability managers to aid in planning and evaluating stress-screening programs is presented. Guidelines are outlined for determining the applicability of screens to different equipment types and for selecting the proper level of assembly at which to apply the screens. An example of how the techniques are applied to a production screening program is provided. While stress screening is now widely employed throughout the defense industry and many experiments and studies on the subject have been conducted, the precise information needed to plan an optimum production stress screening program is still unavailable. Planning must rely on sound judgment and available data from experience. With the proper selection and placement of screens the stress-screening model is a useful tool in screen parameter selection and in providing a quantitative anticipation of screen results. A comparison of actual and anticipated results allows an evaluation of initial assumptions regarding the initial quantity of defective parts, the number of induced defects, and the true screening strength. Consistent differences between actual and anticipated results serve as the basis for altering the screening parameters and maintaining the most effective screening for the resources invested.     

有铅和无铅BGA混装工艺研究

分析比对了有铅和无铅两种焊料的不同温度特性。针对军工产品经常面对的有铅和无铅BGA同时组装在一块印制板上的情况,提出了有铅和无铅BGA混合组装的工艺难点。通过工艺试验列举了混合组装中各个环节所应注意的要点,强调要加强过程控制。最后利用各种可靠性试验和分析证明了混合组装焊点的可靠性。     

Solder Joint Characteristics and Reliability of Lead-Free Area Array Packages Assembled at Various Tin–Lead Soldering Process Conditions

This paper presents a comprehensive study on the effects of critical process conditions on solder joint metallurgy and reliability of mixed-alloy solder joints. The solder joint metallurgy of mixed alloys was characterized and the lead distribution through the solder joint was analyzed, for different package types and under various process conditions. The results showed that the solder paste amount (ultimately the tin percentage (Sn%) in the alloy) and the reflow temperature play critical roles in the mixed-alloy assembly, both in terms of compositional homogeneity and voiding. The reliability of mixed-alloy solder joints was then studied at various process conditions, under different thermal and mechanical stress environments. The study revealed that the sensitivity of the reliability of the mixed-alloy solder joints to the process condition depends on the type of environmental loading.      

环境应力筛选研究

介绍了环境应力筛选方法,分析了筛选效果,通过计算筛选度而衡量了恒温老练筛选效果;结合制订环境应力筛选方案若干问题的研究,在筛选方案优化、被筛选整机的组装等级等方面提出了自己的观点。     

空空导弹定量环境应力筛选方法研究

介绍了环境应力筛选的原理、方法以及在空空导弹上的应用,重点阐述了定量环境应力筛选的参数选择及分析方法。并以某型空空导弹从研制转入批产过程中,产品可靠性的提高在环境应力筛选中的体现为例,初步提出了导弹环境应力筛选的验收判据。     

Electronics reliability: A state-of-the-art survey

This paper gives an overview, as seen at the end of 1979, of the state-of-the-art of reliability physics of electronic components, reliability screening and testing of components and higher levels of assembly, simple MTBF prediction based on component failure rate data, and the modelling and interpretation of “reliability growth” programs.     

移动通信系统设备可靠性筛选试验的应力条件

结合实际工作经验和体会,参考相关标准、规范,以产品实际应 用环境条件为基础,总结了移动通信系统设备可靠性筛选试验的边界条件,探讨了非加速和 加速应力筛选试验的应力选取方法和原则。在传统的可靠性筛选试验基础上,增加了电磁应 力的新研究内容。这更贴近产品实际工作的应力环境,在测试案例中取得了很好的结果。对 科学合理地激发产品缺陷提出了新的思路和方法     

无铅有铅混装焊接技术

针对板级组装过程中出现的有铅无铅混装情况,介绍了无铅混装焊接带来的问题,主要是有铅焊料与无铅元器件以及有铅元器件与无铅元器件之间兼容性问题;针对两种材料熔点差异,需要焊接温度参数调整,提出了设置兼容性温度曲线的解决办法,同时详细说明了兼容性温度曲线优化实验及可靠性验证结果。