共查询到20条相似文献,搜索用时 156 毫秒
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电子设备总剂量辐射屏蔽和防护技术 总被引:4,自引:0,他引:4
核爆产生的X射线和感生的核环境,对电子线路和电子系统会造成严重损伤。强调应用屏蔽防护的重要性,通过进行屏蔽哀减的计算,简述了屏蔽防护的工艺方法。研究表明:通过屏蔽防护厅以有效保护武器电子线路和电子系统的正常工作。 相似文献
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李玉珍 《电子产品可靠性与环境试验》1999,(3):42-44
1引言封装对于电子系统的成本、性能、重量、大小和长期可靠性都有很大的影响。近年来为了解决电子系统小型化、成本降低和可靠性与电性能提高所带来的问题,封装技术得到了迅速的提高。在今后几年中,电子系统还将进一步朝着小型化和高复杂度的方向发展,要在此情况下降... 相似文献
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电磁脉冲武器产生的电磁脉冲,具有独特的传播机制和穿透能力,可利用电子系统固有的电磁特性弱点,在瞬间摧毁、瘫痪大量的电子装备和电子系统。本文介绍了电磁脉冲的产生机制及原理,分析了电磁脉冲特点及对电子系统影响途径,针对电磁脉冲对后勤装备构成的威胁,研究了后勤作业装备、后勤通信方舱以及后勤有线无线通信装备的电磁脉冲防护方法,并提出了加强后勤装备电磁脉冲防护研究建议。 相似文献
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何兴仁 《大气与环境光学学报》1994,(5)
用于电子系统的光互连及其进展何兴仁(电子工业部44所)1前言随着电子系统高度集成化、高性能化、系统各部分之间电互连弓!起的时间延迟、窜扰等问题已日渐突出。把光信号传输所具有的高速率、大容量、低功耗、抗干扰等诸多优点用于互连,可望解决上述问题。最明显的... 相似文献
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为解决综合化航空电子系统中冷重启动时大电流冲击导致的电子元器件加剧老化问题,以及避免冷重启动时系统中无需重启动部分正常工作被中断现象,提出将热重启动引入综合化航空电子系统设计中。结合综合化航空电子系统的控制结构和处理器的复位功能,分析了热重启动在综合化航空电子系统中实现的可行性,给出了实现热重启动的软硬件设计方法。经过实验验证,热重启动能够有效解决冷重启动方式在综合化航空电子系统的弊端。 相似文献
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本文以一种裂隙梁型接触端子为对象,结合显式时间积分法和罚接触算法,动态地仿真接触端子与印刷电路板(PCB)间直通型微孔的金属衬套(电镀通孔(PTH))的插接过程,分析接触端子的结构对于连接可靠性的影响。研究发现汽车电子连接器用裂隙梁型接触端子插接过程PTH可能发生塑性变形而破坏,此结论对汽车电子连接器用接触端子的微小型结构设计具有指导性意义。 相似文献
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Anisotropic conductive films (ACFs) received a great deal of attention in recent years for interconnection applications in electronic packaging. This paper reports the behaviour of ACF joints under various mechanical loading, i.e., die shear and cyclic fatigue in shear. The mechanical behaviour of ACF joints that have been exposed to environmental effects, i.e., high moisture and elevated temperature (autoclave test conditions) has been examined using die shear test. The maximum shear force prior to fracture was determined as 465.0 N, at which the contact resistance is found extremely high and can be considered as open circuits. Epoxy based ACF exhibits insignificant plastic deformation, especially for samples that have undergone autoclave test. Reduction trend was observed in the shear moduli over autoclave test time for ACF joints. Fracture surface of ACF that failed in shear test shows spalling and less plastic deformation after exposed to autoclave test. For cyclic fatigue test, the endurance limit is determined at about 143.5 N and the corresponding calculated endurance ratio is around 32.0%. 相似文献
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Ken-Ichi Ohguchi Katsuhiko Sasaki Masahiro Ishibashi 《Journal of Electronic Materials》2006,35(1):132-139
A method to separate plasticity and creep is discussed for a quantitative evaluation of the plastic, transient creep, and
steady-state creep deformations of solder alloys. The method of separation employs an elasto-plastic-creep constitutive model
comprised of the sum of the plastic, transient creep, and steady-state creep deformations. The plastic deformation is expressed
by the Ramberg-Osgood law, the steady-state creep deformation by Garofalo’s creep law, and the transient creep deformation
by a model proposed here. A method to estimate the material constants in the elasto-plastic-creep constitutive model is also
proposed. The method of separation of the various deformations is applied to the deformation of the lead-free solder alloy
Sn/3Ag/0.5Cu and the lead-containing solder alloy Sn/37Pb to compare the differences in the plastic, transient creep, and
steady-state creep deformations. The method of separation provides a powerful tool to select the optimum lead-free solder
alloys for solder joints of electronic devices. 相似文献
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In this paper, we have described a new simultaneous 3-D optical system for characterizing electronic packages. This optical system is able to capture high resolution, online whole field data set. We are able to use this optical system to determine the coefficient of hygroscopic expansion (CHE) in moulding compound by correlating the weight gain and hygro-strain information obtained. In this study, we have used this optical system to evaluate the hygroscopic expansion of a fully cured moulding compound, XJA-9. We have also studied the effect of moisture diffusion on the deformation of plastic IC package. It was found that moisture diffusion could reverse the warpage of the plastic package. The study showed that moisture may cause severe changes to the internal stress field of plastic packages that would usually occur unnoticed or underestimated. 相似文献
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随着光学塑料成型技术的不断发展,光学塑料透镜在各类光学系统中得到了广泛的应用。光学塑料具有便于大批量生产,设计灵活性高,重量轻和耐冲击等特点。本文进一步研究了光学塑料的特性,并结合激光制导武器光学系统的特点,分析光学塑料应用的可行性。在以上分析的基础上针对特定的光学系统参数,完成基于非球面光学塑料的光学系统设计,并对系统的光斑成像质量进行了分析,满足系统的使用要求。最后,针对光学塑料对温度变化比较敏感的问题,利用LightTools软件完成对激光制导武器探测系统的建模,分析不同温度环境下系统输出的和差比幅值偏差和角度的偏差,进一步验证光学塑料为系统带来的影响,确定其在光学系统中的适用性。 相似文献
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Failure mechanism models for plastic deformation 总被引:1,自引:0,他引:1
A tutorial illustrating designs in which plastic deformation can endanger system performance, thereby acting as an overstress failure mechanism, is presented. Analytic methods, based on continuum mechanics, are presented to design against such failures. Examples illustrate the use of these models in practical designs encountered in mechanical systems and in electronic packaging 相似文献
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激光涂层零件的多冲碰撞形变效应与分析 总被引:1,自引:0,他引:1
报道了多冲碰撞载荷下激光涂层零件塑性变形现象。利用坐标网格法、显微分析法等分析了激光涂层零件的多碰累积变形现象和规律。这种塑性变形在常温即可发生,且具有低应力和累积特性。变形发生在涂层表面及以下一段区域内,并由大到小呈梯度变化。碰撞能量驱动、冲击温升效应、晶界滑动与迁移、亚结构的形成与孪晶等,是引起多碰累积变形的可能原因。 相似文献