脉冲螺线行波管热状态分析及ANSYS模拟

本文对国外上世纪90年代的产品,高输出功率高工作比的脉冲行波管进行热状态的分析,通过计算全面了解国外行波管的热设计要求及必要的工艺措施,为国内同类型行波管提高可靠性服务.文中对国内同类型产品的表面热阻率进行测量,从初步分析结果指出减小表面热阻率的方向和措施.使用ANSYS软件实际模拟仿真螺线行波管,得到更为准确、可靠的结果,并和设计计算基本保持一致.     

行波管电镀铜螺旋线高温处理后变色问题的实验分析

对行波管螺旋线电镀铜工艺进行了描述和分析,从实验上阐明了烧氢后螺旋线表面颜色变化的原因。实验分析表明,Ni-Cu合金化反应是导致颜色变化的主要原因,而合金化的结果使表面电导率、热导率大大降低,因此,电镀铜工艺不适合于行波管螺旋线的表面处理。在此基础上,对螺旋线镀铜工艺的其他技术方案进行了评述。     

用于行波管螺旋慢波组件的挤压新方法

在螺旋慢波结构行波管制作中，螺旋慢波组件冷挤压是其中工序之一。本文提出了一种用于行波管螺旋慢波组件的挤压新方法并自制了相应的冷挤压设备样机。该设备可以用于以弹压法制作行波管的螺旋慢波结构，能够满足行波管的工艺要求，所制作慢波组件在一致性上有所提高。     

W波段行波管发展评述

本文主要介绍了目前国内外W波段行波管的研究现状及所达到的技术水平,对相关的慢波电路结构、电子光学系统及相关的加工工艺进行了分析。同时还对进一步提高W波段行波管输出功率、拓宽行波管带宽、改善电子注流通和耦合装置匹配性能等技术手段进行了研究和分析。     

螺旋线毫米波行波管及宽带毫米波功率模块的研制进展

本文介绍了中国电科12所K、Ka波段螺旋线行波管及毫米波功率模块研制进展情况,包括宽带行波管及毫米波功率模块,大功率通信/雷达用行波管、幅相一致行波管。目前已实现Ka波段小型化的宽带行波管及毫米波功率模块输出功率大于160 W;Ka波段幅相一致行波管相位一致性达到±25°;大功率毫米波行波管已形成系列化产品。     

脉冲行波管阴极蒸发现象的验证与解决

针对某型脉冲行波管工作中出现失效的问题,通过试验分析确定失效是由阴极蒸发所致,在对阴极进行试验研究的基础上,找出了阴极的蒸发规律,通过采取改进阴极预处理工艺和适当降低阴极温度等措施,解决了阴极改盐后产生的蒸发问题;而增加行波管测试老炼时间,则提高了行波管工作稳定性和质量一致性。     

脊加载环板行波管的理论与实验研究

脊加载环板行波管是一种频带相对较宽的大功率行波管 ,本文对脊加载环板慢波系统及其改进型进行了研究 ,理论与实验良好符合 ,实验表明脊加载环板慢波系统的改进型比脊加载环板慢波系统具有更宽的频带 ;同时对慢波系统采用等效线路模型 ,电子注采用二维圆环模型 ,研究了脊加载环板行波管的大信号特性 ,讨论了注波互作用的非线性效应。本文的结果将为脊加载环板行波管的设计提供理论基础。     

回旋行波管高质量阴极及电子枪研究

回旋行波管对回旋电子注参数（纵横速度比、速度零散等）非常敏感,实验中需进行电子参数调节,高质量电子枪研制是整管设计核心之一。基于理论分析、结构分析及热分析等对回旋行波管电子枪进行改进设计,对阴极、热子进行优化设计,研发的电子枪速度零散＜2%,优于国际报道的3%。项目在热分析和形变分析基础上,改进了阴极结构及制备工艺,显著提高了热子加热效率,将阴极加热功率从100W降低至50W左右,提升了阴极发射的均匀性和稳定性,10%工作比下长时间工作稳定、可靠,有效保障了阴极寿命,新研电子枪在Ka频段回旋行波管装管实验,脉冲功率100kW,平均功率10kW,连续工作稳定、可靠。     

4cm大功率耦合腔行波管的研制

介绍了一只近期研制的 4cm大功率耦合腔行波管的情况 ,并对研制过程中出现的技术问题及其解决措施进行了简要介绍。     

反射装配型行波管在空间通信中的应用

本文介绍反射型放大器的应用特点和通信卫星上装配的中继器原理图及其反射装配方法。文中列出了为中继器所研制的特殊行波管样管的电特性,并从性能和可靠性角度与普通行波管进行了比较。最后介绍能应答整个通信系统的中继器的设计略图。     

Reliability growth modeling for in-service electronic systems considering latent failure modes

A latent failure mode is a type of failure that may not occur until the system has operated in the field for a certain period of time. Predicting latent failures is often difficult, but it has a great importance for reliability management in terms of system maintenance and warranty services. This paper proposes a stochastic model to predict the reliability growth for field or in-service electronic systems considering latent failures. The proposed model can be applied to electronics industries where extended in-house reliability testing cannot be implemented due to the tight design schedule. Based on the new method, the product management can proactively implement corrective actions against key failure modes using relevant engineering resources. A discussion between the effectiveness of corrective actions and the associated cost is also provided. Finally, field failure data collected from a fleet of automatic test equipment are used to demonstrate the applicability and performance of the model.     

Failure Analysis-assisted FMEA

In this paper, ordinary FMEA (Failure Mode and Effects Analysis) was applied during the design phase of an electric motor control system for vehicle HVAC (Heating/Ventilation/Air Conditioning). The analysis of the field data from the second year forces to review FMEA. The corrective actions, planned on the basis of the sole failure mode, as usual in FMEA, proved to be inadequate and Failure Analysis was performed to understand the failure mechanism of the indicted component and integrate. New proper corrective actions were devised and successfully implemented.     

Failure analyses for debug and ramp-up of modern IC’s

Quick and successful failure analysis is a key component for in-time realization and ramp-up of new products. The structure of analysis flow from verification of failure to fault identification and corrective actions is presented with the focus on modem techniques in fault localization. For the area of design debug techniques for internal probing and circuit modification by mask less redesign are described, yield learning is demonstrated on the example of SRAM fails and scan shift loss. Finally an assessment of the future of failure analysis in this field is given.     

手机PCB镀金接插件腐蚀失效实例分析

通过两个带有镀金接插件的手机PCB腐蚀失效的实例．从元件表面出现的腐蚀失效的现象出发．结合这些失效部位的腐蚀形貌、腐蚀产物等特点,分析了手机PCB上接插件镀金表面层在自然存放条件和加速腐蚀条件下出现腐蚀失效、达不到有效保护作用的主要原因,包括表面镀金层本身存在孔隙、划痕等表面缺陷．电镀过程中引入污染物,装配过程中形成缝隙等;另一个重要原因是镀金层厚度薄,不能提供足够的防护性能。并针对这些因素提出了相应的改善措施和建议。     

分析故障数据,提高软件测试的缺陷发现率

在软件的确认测试中，如果能够对故障数据进行相关的分析，就可以实时地了解被测软件的故障分布情况，并采取相应的措施和方法，从而提高软件测试的缺陷发现率。     

引线镀层材料不当造成塑封器件漏电失效

对漏电失效的塑封三极管,通过显微观察、去除异物前后的电性能对比分析、能谱成分分析等技术手段,揭示了因引线镀层材料采用不当引起银迁移致使器件漏电失效的失效模式及失效机理,并提出了相应的建议措施.     

Computing instationary availability for maintained systems

The present paper is dedicated to numerical methods of computation of the instationary availability of Boolean systems. Times for corrective repair actions as well as for preventive repair actions are supposed to be random. Lifetime of the system is also considered to be random. Moreover, random variations of the maintenance intervals are taken into account. Edgeworth expansions and Laguerre series expansions are used to compute the availability numerically. Examples are given to show the exactness of the computation methods.     

A Reliability Growth Projection Model for One-Shot Systems

This paper offers several contributions to the area of discrete reliability growth projection. We present a new, logically derived model for estimating the reliability growth of complex, one-shot systems (i.e., the reliability following implementation of corrective actions to known failure modes). Multiple statistical estimation procedures are utilized to approximate this exact expression. A new estimation method is derived to approximate the vector of failure probabilities associated with a complex, one-shot system. A mathematically-convenient functional form for the s -expected initial reliability of a one-shot system is derived. Monte-Carlo simulation results are presented to highlight model accuracy with respect to resulting estimates of reliability growth. This model is useful to program managers, and reliability practitioners who wish to assess one-shot system reliability growth.     

Semiconductor Instability Failure Mechanisms Review

This paper reviews the mechanisms of semiconductor instabilities for the purpose of better understanding this very complex phenomenon. As a result of this understanding, the semiconductor instabilities can be kept to a minimum in design and production. The basic ideas, diagrams, and references are presented for: instabilities due to surface charge on the silicon dioxide (SiO2), conduction on oxide surfaces/lateral charge spreading, instabilities caused by charges within the SiO2, instabilities in double-layer insulator structures, hFF degradation by avalanched emitter-base junction, and instabilities due to parasitic actions. A case study in reducing manufacturing assembly fallout is presented. Its electrical manifestations, as hFF degradation, the causes and corrective action are described. This study shows the importance of vendor-user cooperation to find the proper corrective action. Electrical diagnostic techniques such as the current-voltage curve trace characteristics of a junction are reviewed. The threshold test used in detecting parasitic MOS action caused by improper layout and/or ionic contamination is presented. They are used to pinpoint the area of instability on the semiconductor. High temperature bake and biased operating life procedures and their use in identifying and pinpointing causes of instabilities are discussed. Finally a method for removing various materials and/or layers of a semiconductor device is presented. This method is used in pinpointing the manufacturing step which might have caused the observed abnormal electrical characteristics.     

强化质量管理,确保航天装备质量

本文从全过程质量控制、软件质量管理、工艺设计技术、建立FRACAS(故障报告、分析和纠正措施系统)及质量问题归零等方面阐述了航天装备质量管理的要点和难点,以及航天装备质量管理要点和难点的解决方法,从强化质量管理的角度,论述了如何确保航天产品质量.