共查询到18条相似文献,搜索用时 312 毫秒
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针对高可靠性产品寿命数据少、获取成本高的问题,基于充分利用产品在研制、加速试验等不同环境下的退化数据、失效数据等可靠性数据的思想,提出了一种融合非线性加速退化模型和失效率模型的产品寿命预测方法.首先,根据退化数据对非线性退化过程进行分析,估计退化过程的参数;然后,根据加速退化数据及相应的加速退化模型估计加速退化模型的参数,从而得到退化参数与应力之间的关系.进一步,利用比例风险模型融合产品的寿命数据和未失效截尾数据,并基于此计算产品的可靠度函数、预测产品的寿命.实例应用验证了所提方法的有效性,同时说明了所提方法的应用价值. 相似文献
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基于步进加速退化试验的某型电连接器可靠性评估 总被引:1,自引:0,他引:1
某导弹电连接器属于高可靠性、长寿命产品,在短时间内很难获取其失效数据。为了评估其可靠性,在分析其失效机理的基础上设计了步进应力加速退化试验,通过分析加速退化数据外推出产品在正常工作应力水平下的可靠度函数。试验中,以电连接器的接触电阻作为性能参量,选取温度作为加速应力。数据分析时利用Wiener随机过程对样品退化进行建模,为了提高模型参数的估计精度,采用极大似然法对所有性能退化数据进行整体统计推断。结果表明,提出的基于加速退化数据分析的方法实用、有效,实现了某导弹电连接器的可靠性评估并可为其他高可靠性产品的可靠性评估工作提供参考。 相似文献
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尤明懿 《电子产品可靠性与环境试验》2014,(1):27-31
提出一种基于可靠性预计数据的星载电子产品老练试验加速因子的估计方法。在该方法中,温度对产品失效过程的影响通过器件失效率预计模型中的温度应力参数予以刻画。通过比较产品在工作环境温度与老练试验温度下的预计失效率数据来估计老练试验加速因子。该方法简单、易行,含义明确,有望增强可靠性评估结果与可靠性预计结果的可比性。 相似文献
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随着国防装备的快速发展,对型号的可靠性和寿命提出了更高的要求。为满足型号的高可靠、长寿命要求,可靠性试验成为目前研究的重点。以火箭发射平台所用的液体摆水平传感器为研究对象,分析液体摆在环境温度应力作用下的失效原因;选择适用的加速退化模型,建立一种基于加速性能退化的可靠性模型,并通过试验评估进行论证。 相似文献
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The existing standard reliability models for power devices are not satisfactory and they fall short of predicting failure rates or wear-out lifetime of semiconductor products. This is mainly attributed to two reasons; the lack of a unified approach for predicting device failure rates and the fact that all commercial reliability evaluation methods relay on the acceleration of one dominant failure mechanism. Recently, device reliability research programs are aimed to develop new theoretical models and experimental methods that would result a better assessment of the device lifetime as well as point out on the dominating failure mechanism for particular operating conditions. A new model, named Multi failure mechanism, Overstress Life test (MOL) has been introduced and posed a better understanding of the dominating failure mechanisms under various stressed conditions in advanced FPGA devices (for 45 and 28 nm technologies). In this work we present, for the first time, the implementation of the MOL model to investigate the reliability of silicon power MOSFET and GaN power FET devices. Both, LTSpice simulation and experimental data are presented for a test circuit of a ring oscillator, based on CMOS-FET, NMOS-FET, PMOS-FET and N-channel e-GaN FET. The monitored data was acquired in-situ in form of the ring frequency or Vds values that enabled to assess the lifetime and determine the dominating mechanism during accelerated wearout by temperature, applied bias voltage, thermal cycling, gamma and electron irradiation. Moreover, in the case of GaN devices, RDS-On monitoring circuit has also been operated during thermal cycling of the tested component and the acceleration factor was derived for various operational parameters. 相似文献
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The use of accelerated step-stress and constant stress-in-time test techniques is demonstrated for generating models for predicting reliability at use conditions. Reliability prediction models were obtained for a signal diode, signal and power transistors, silicon trolled rectifier, and metal oxide varistor. Each of these device types follows the Arrhenius model for reliability prediction. Techniques are demonstrated for determining 1) the acceleration factor between extremely high acceleration testing conditions and field operating conditions on the signal diode; and 2) the acceleration or multiplying factor between high level stresses and use conditions which can be used to predict the performance of the signal diode over time. The effect of relative humidity on reliability is discussed. Devices under power operation have a lower relative humidity (RH) than the environment. This low RH suppresses humidity activated mechanisms. A transistor high-reliability screen which removes devices with early manufacturing type defects is described. This screen was effective, efficient and economical for improving the reliability of systems. A technique of combining acceleration factors for a number of items which affect reliability was demonstrated for the diode. This same technique should be useful for most device reliability predictions. The acceleration factors, however, can not be extrapolated into stress levels much above maximum ratings where new failure modes may appear that override the established failure rate relation with stress. The straight line plots of failure rates in this paper are terminated before these threshold limits. 相似文献
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Battery life prediction is critical for lithium/thionyl chloride cells with a long storage life. The objective of this study was to develop models for rapidly estimating the storage life of Li/SOCl2 cells using the semiempirical approach. An accelerated degradation test involving numerous cells stored at various temperatures (room temperature or RT, 40, 50, 60, and 70 °C) was conducted to investigate the effect of the storage time and temperature on capacity degradation. The degradation law can be summarized on the basis of the test data for constructing the semiempirical equation; this law demonstrates that the residual capacity of aging cells exponentially changes with the storage time and temperature. The degradation data are also used for parameterization with the multiple nonlinear curve fitting method based on the universal global optimization algorithm. According to the simulation and comparison between the experimental data and prediction curve, the fitting prediction curve accurately fits the experimental data. This finding indicates that the semiempirical model is useful because of its satisfactory ability to approximate the measured data. In addition, characteristic values of the battery, including the storage life under various storage conditions, average self-discharge rate, and acceleration factor, can be calculated on the basis of the mathematical model. 相似文献
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三参数Weibull分布拟合LED照明灯寿命的优势较为明显,但要得到三参数Weibull分布参数较为精确的点估计较为困难。目前常用的参数估计方法有极大似然法、矩估计法、Bayes估计法等,由于其计算的方程复杂,导致软件编程繁琐,不易掌握,而且也不一定能得到参数估计。鉴于此,文章针对恒加试验提出一种简便地求解三参数Weibull分布参数估计的方法,该方法不涉及超越方程的求解问题,软件编程相当简单,且统计思想清晰。通过LED照明灯恒加试验下的几个案例数据说明方法的应用,并与已有的方法做了对比分析。 相似文献
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Min-Hsiung Hsieh Shuen-Lin Jeng 《Reliability, IEEE Transactions on》2007,56(3):369-380
Using degradation measurements is becoming more important in reliability studies because fewer failures are observed during short experiment times. Most of the literature discusses continuous degradation processes such as Wiener, gamma, linear, and nonlinear random effect processes. However, some types of degradation processes do not occur in a continuous pattern. Discrete degradations have been found in many practical problems, such as leakage current of thin gate oxides in nano-technology, crack growth of metal fatigue, and fatigue damage of laminates used for industrial specimens. In this research, we establish a procedure based on a likelihood approach to assess the reliability using a discrete degradation model. A non-homogeneous Weibull compound Poisson model with accelerated stress variables is considered. We provide a general maximum likelihood approach for the estimates of model parameters, and derive the breakdown time distributions. A data set measuring the leakage current of nanometer scale gate oxides is analyzed by using the procedure. Goodness-of-fit tests are considered to check the proposed models for the amount of degradation increment, and the rate of event occurrence. The estimated reliabilities are calculated at lower stress of the accelerated variable, and the approximate confidence intervals of quantiles for breakdown time distribution are given to quantify the uncertainty of the estimates. Finally, a simulation study based on the gate oxide data is built for the discrete degradation model to explore the finite sample properties of the proposed procedure. 相似文献
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讨论了4种用于描述加速寿命试验中失效分布参数和环境条件之间关系的失效物理模型。针对阿伦尼斯模型,探讨了加速寿命试验中的参数估计方法,构建了参数的极大似然估计(MLE)方程组,解得加速寿命试验中失效分布参数的MLE值,进而通过转化,借助于标准正态分布表获得其寿命指标的近似值,并通过一个实例介绍了其具体应用。 相似文献
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A general degradation model which includes conventional acceleration tests such as fixed, progressive, and step stress experiments is derived from the reaction theory under the assumption of linear degradation accumulation. Its application to the acceleration test is discussed. According to the reaction theory, degradation of the characteristic parameter, ? is connected to reaction rate K and time t by a linear transformation function f(?) = Kt. The total degradation is determined by the linear accumulation of the Kiti product such as f(?n)= # Kiti. This relationship is also expressed as a generalized Miner's equation #(ti/Li) = 1 in which ti and Li are the actual stressing time and expected life under the ith stress condition, respectively, and # ti is the life expectancy of the component under successive stress conditions from i = 1 to n. Validity of this linear accumulation assumption is investigated under various stress application paths. For monotonic step-up, cyclic, and random stress, the rule almost holds as a whole, but monotonic step-down stress sometimes causes erroneous recovering effects of the parameter. The degradation accumulation principle is effectively applicable to integrate degradation and failure pattern information and also to avoid some shortcomings of conventional life test methods. 1) For example, in order to find efficiently the life vs. stress plot, we could combine the degradation (failure fraction) vs. stress diagram, obtained by one step stress experiment, and the knowledge of the degradation pattern obtained by a constant stress test. 相似文献