Reliability life-testing and failure-analysis of GaAs monolithicKu-band driver amplifiers

`Gallium-arsenide monolithic microwave integrated-circuit (MMIC) Ku-band driver amplifiers were life tested under accelerated high temperature, DC and RF conditions until failure. These MMIC are used in various applications such as radar and satellite communication systems. The failure mechanisms controlling their reliability must be understood in order to improve the lifetime for these and other applications. This paper discusses the experimental procedures, statistical evaluation of the data and failure analysis of the devices. To the authors' knowledge, this is the first report of RF life testing of dual-gate driver amplifiers. The majority of the devices failed catastrophically due to high drain current, while others failed parametrically due to low output power. Failure analysis indicates that degradation of the Si₃N₄ dielectric layer to be the main failure mechanism in these MMIC. Statistical analysis revealed an activation energy of 0.87 eV and a median lifetime of 5.8·10⁴ hours at 140°C channel temperature, which is consistent with surface-phenomena failure mechanisms     

TAP及其应用

TAP(Test Access Port/Traffic Access Port)是一种新兴的用于网络监测的硬件设备,它提供了一种在不中断网络正常流量的情况下,获得网络流量的方法.因此,TAP可以用来实现监测网络性能、解决网络故障、分析网络流量和阻止恶意攻击等一系列功能.文章阐述了TAP的产生背景、主要特点、工作原理及其应用.     

ESD sensitivity of a GaAs MMIC microwave power amplifier

The EOS/ESD sensitivity of the main circuit blocks of a complete GaAs multi-stage power amplifier for microwave applications was investigated under HBM, MM and TLP regimes. Hard breakdown failure modes were identified due to passive components failure. The high current injection state of active components was also analyzed.     

二维固态有源相控阵失效单元补偿新方法

提出二维固态有源相控阵失效单元补偿的新方法，该方法基于失效单元矩形切割和线性规划方法。可适用于有源阵列多单元任意失效分布的实时补偿。在保证失效补偿后两主平面副瓣性能完全恢复的情况下，用线性规划方法对空间平均融瓣进行了优化。由于采用实数算法，仅需对非失效单元的幅度进行调整。理论分析及模拟计算表明该方法在工程应用中是切实可行的。     

Multihop Ad Hoc Networking: The Theory

This article reviews the basic principles behind mobile ad hoc networks (MANET) and critically discusses approximately ten years of research in this field. We summarize the main achievements and point out the limits of MANET research. This research was conducted under the assumption that the networks mainly will be used for large-scale general consumer applications, and nodes would be ubiquitous, thus reasonably dense and active. Both assumptions do not reflect reality and certainly would not be true in an initial phase of deployment. A lack of realism regarding the objective of MANET coupled with a lack of realism during the design of MANET are the main causes of MANET running a high risk of failure     

Analysis of deep submicron VLSI technological risks: A new qualification process for professional electronics

A large range of commercial deep submicron VLSI devices are used for avionic designs. Due to the scaling down, an ever higher level of integration and the use of new materials in foundries, the main failure mechanisms are changing while new ones appear. Lifetimes related to these failure mechanisms are suspected of being shorter and shorter so failure rate prediction becomes a great challenge for deep submicron (DSM) semiconductor reliability. We propose in this paper, a new approach based on technologies analysis in order to determine potential reliability risks regarding the specific use of DSM components for avionic applications.     

A Hybrid Timer Based Single Node Failure Recovery Approach for WSANs

The inter-actor connectivity is a very crucial issue to maintain network operation in the wireless sensor and actor networks. Most of the applications have been proposed for harsh environments where the backbone actor nodes are prone to failure or get damaged due to their battery power exhaustion or get physically damaged. Such failures can partition the network due to failure of the cut-vertex node and eventually decrease the network performance or even sometimes make the network useless. Currently, a few approaches have been proposed to restore the partitioned network due to failure of the cut-vertex node but without considering the recovery node capabilities. This paper proposes a localized hybrid timer based cut-vertex node failure recovery approach called distributed prioritized connectivity restoration algorithm (DPCRA) to handle such partitions and restore connectivity with the help of a small number of nodes. The main idea is to proactively identify whether the failure of an actor node causes partition or not in the network. If partition occurs the designated failure handlers (FHs) detect that partition and repair it locally using minimum information stored in each actor node. In case first designated node is unable to start the recovery process within a permissible reaction time the next designated FH could start the recovery process. The main strength of our paper is the use of multiple backup nodes for the guaranteed partitioned recovery. The experimental simulation shows that DPCRA outperforms other existing state-of-the-art approaches in terms of the number of participated repairing nodes and their total moving distance for the recovery to restore the disconnected partitions.     

中波广播发射机功放问题与解决建议研究

调频广播发射技术的核心载体源自广播发射机,其中国内又主要以中波发射机为主.因此,研究中波广播发射机的故障是确保广播发射工作有序开展的先决条件,具有重要的现实意义.本文以国内广播电台应用广泛的DAM-50KW中波广播发射机为例,对维护功放模块的损坏问题和解决检测方法展开分析和总结.     

Failure rate estimation of known failure mechanisms of electronic packages

Product reliability is one of the key factors for a successful product launch. However, electronic components can still fail in various stages of applications due to certain failure mechanisms. A constant failure rate typically describes a majority of non-solder joint related package failures in the accelerated testing or the field application. Historically, the failure rate for a constant failure phenomenon is estimated by using the Chi-square value or the expected number of failures.This paper will discuss the statistical characteristics of the number of failures observed in tests or applications and their confidence bounds. Several methods used to estimate the confidence bounds will be described, and a new approach will be proposed and validated through case studies. The estimation of the acceleration factor (AF) used in the failure rate modeling is also discussed. The conclusion will help engineers to understand the statistical meaning of the failures observed in stress tests or in the field applications, additionally, obtain a meaningful failure rate based on the expected failure data.     

白光LED的失效机理分析

论述了白光发光二极管(LED)在封装和应用中存在的主要模式和失效机理,并介绍了若干失效分析实例,提出了可靠性保证措施,对于进一步完善白光LED封装技术、提高其寿命和可靠性提供参考.

Abstract：

Discussed are the main failure modes and mechanisms of white LEDs during the processes of package and applications. Several cases for analyzing the failures are introduced. Finally, some reliability assurance measures are suggested to improve the lifetime and reliability of white LEDs, which are helpful for further improvement of the packaging technology.     

The use of the focused ion beam in failure analysis

Since the introduction of the Focused Ion Beam (FIB), many applications have been developed. This article deals with a stand alone FIB in a failure analysis laboratory where it is used for material characterisation and sample preparation. In this paper examples will be given of FIB applications as used for failure analysis and process monitoring of semiconductor devices.     

A review of induction motors signature analysis as a medium forfaults detection

This paper is intended as a tutorial overview of induction motors signature analysis as a medium for fault detection. The purpose is to introduce in a concise manner the fundamental theory, main results, and practical applications of motor signature analysis for the detection and the localization of abnormal electrical and mechanical conditions that indicate, or may lead to, a failure of induction motors. The paper is focused on the so-called motor current signature analysis which utilizes the results of spectral analysis of the stator current. The paper is purposefully written without “state-of-the-art” terminology for the benefit of practising engineers in facilities today who may not be familiar with signal processing     

Online multiple-model-based fault diagnosis and accommodation

While most research attention has been focused on fault detection and diagnosis, much less research effort has been devoted to failure accommodation. Due to the inherent complexity of nonlinear systems, most model-based analytical redundancy fault diagnosis and accommodation (FDA) studies deal with the linear systems, which are subjected to simple additive or multiplicative faults. This assumption has limited the effectiveness and usefulness in practical applications. In this paper, the online fault accommodation (FA) control problems under multiple catastrophic or incipient failures are investigated. The main interest is focused on dealing with the unanticipated component failures in the most general formulation. Through discrete-time Lyapunov stability theory, the sufficient conditions to guarantee the system online stability and to meet performance criteria under failures are derived. A systematic procedure for proper FA under the unanticipated failures is developed. The approach is to combine the control technique derived from discrete-time Lyapunov theory with the modern intelligent technique that is capable of self-optimization and online adaptation for real-time failure estimation. In addition, a complete architecture of FDA is proposed by incorporating the intelligent fault tolerant control strategy with a cost-effective fault detection scheme and a multiple-model based failure diagnosis process to efficiently handle the false alarms and the accommodation of both the anticipated and unanticipated failures in online situations. The simulation results, including a three-tank benchmark problem, substantiate the feasibility study of the proposed FDA framework and provide a promising potential to spin-off applications in industrial and aerospace engineering.     

Novel failure mode of chip corrosion at automotive HALL sensor devices under multiple stress conditions

Semiconductor devices used in automotive applications undergo numerous stress situations depending on their particular application. Corrosion, as one main crucial failure mechanisms, can affect the lifetime of electronic components on system, device or even die level. In this paper, a novel corrosion mechanism on HALL sensor devices is investigated and clarified. This corrosion is only occurring under complex conditions like layout aspects, ionic impurities combined with humidity penetration and thermo-mechanical strain due to packaging and additional mechanical load from further over moulding. It is shown how advanced physical and chemical analysis can be combined with finite element simulation to ascertain a chemical degradation running on silicon, silicon dioxide and metallisation level to derive the complete chemical reaction mechanism for the observed corrosion defects. To verify the new failure mode, experiments to recreate this type of corrosion were carried out. Finally, conclusions are drawn on how failure modes can be prevented and how the robustness of the HALL devices under harsh environments can be increased.     

Study of a failure mechanism during UIS switching of planar PT-IGBT with current sense cell

IGBT with sense emitter cells are used in power applications where current sensing or feedback is needed to guarantee safe operation of the switching device. In this paper we show, by experimental measurements and simulations, how the coupling of undesired voltages to the sense cell that is disconnected from the main IGBT emitter is able to trigger the latch-up of the entire device during inductive switching leading to its failure. Being able to reproduce the failure phenomenon by 2D simulations we are able to identify the possible physical cause of this phenomenon.     

超高亮度发光二极管芯片切割技术

介绍了超高亮度发光二极管(UHB-LED)芯片切割工艺中砂轮切割、金刚刀划片及激光切割的应用情况、工艺原理、工艺特点和发展前景.结合生产实践,对比和分析了不同切割工艺的优缺点,针对不同切割生产工艺中存在的芯片正崩、芯片背崩、芯片脱落以及划片裂片不良等问题进行了探讨并提出了解决方法.指出激光切割技术是LED芯片切割工艺发展的必然趋势.     

一种GaAs PHEMT器件的失效分析

随着Ga As PHEMT(赝配高电子迁移率晶体管)器件的广泛应用,器件的可靠性及失效分析方法越来越受到人们的重视。该文采用半导体参数分析仪、聚焦离子束(FIB)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、能谱仪(EDX)等分析方法对一种PHEMT器件进行失效分析,为实际生产和加工过程中的失效分析提供了参考。     

基于随机Petri网的网络可信赖性分析方法研究

随着人们对计算机网络系统的依赖性的不断增强,网络系统的可信赖性研究变得越来越重要.本文首先对可信赖性的概念及其主要性能指标进行论述,并对系统可信赖性各种模型方法及求解特点作了分类比较.在此基础上研究了随机Petri网(SPN)对网络系统可信赖性建模分析的方法和步骤,着重研究了随机Petri网描述系统的服务失效模型和容错模型,并给出了网络系统可信赖性分析中主要指标的计算方法.最后对于应用随机Petri方法分析网络系统可信赖性时存在的问题以及研究现状作了分析和总结,并对今后研究的方向进行了展望.     

Bioinspired Self-healing Soft Electronics

Inspired by nature, various self-healing materials that can recover their physical properties after external damage have been developed. Recently, self-healing materials have been widely used in electronic devices for improving durability and protecting the devices from failure during operation. Moreover, self-healing materials can integrate many other intriguing properties of biological systems, such as stretchability, mechanical toughness, adhesion, and structural coloration, providing additional fascinating experiences. All of these inspirations have attracted extensive research on bioinspired self-healing soft electronics. This review presents a detailed discussion on bioinspired self-healing soft electronics. Firstly, two main healing mechanisms are introduced. Then, four categories of self-healing materials in soft electronics, including insulators, semiconductors, electronic conductors, and ionic conductors, are reviewed, and their functions, working principles, and applications are summarized. Finally, human-inspired self-healing materials and animal-inspired self-healing materials as well as their applications, such as organic field-effect transistors (OFETs), pressure sensors, strain sensors, chemical sensors, triboelectric nanogenerators (TENGs), and soft actuators, are introduced. This cutting-edge and promising field is believed to stimulate more excellent cross-discipline works in material science, flexible electronics, and novel sensors, accelerating the development of applications in human motion monitoring, environmental sensing, information transmission, etc.