Comparison of Aluminum Electrolytic Capacitor Lifetimes Using Accelerated Life Testing

2014 ◽  
Vol 2014 (1) ◽  
pp. 000662-000667 ◽  
Author(s):  
Stephani Gulbrandsen ◽  
Joelle Arnold ◽  
Greg Caswell ◽  
Ken Cartmill
Keyword(s):  
Weight Loss ◽  
Operating Conditions ◽  
Accelerated Life Test ◽  
Electrolytic Capacitor ◽  
Time To Failure ◽  
Equivalent Series Resistance ◽  
Aluminum Electrolytic Capacitor ◽  
Critical Weight ◽  
Accelerated Life ◽  
Speed Up

This research compared the lifetime of similar aluminum electrolytic capacitors from different manufacturers using an accelerated life test, which consisted of critical weight loss testing and rate of weight loss testing. In critical weight loss testing, capacitors are perforated to speed up electrolyte evaporation and the equivalent series resistance (ESR) and weight are measured periodically to determine their relationship. In rate of weight loss testing, capacitors are subjected to final operating conditions (i.e. voltage and ripple current are applied) and the weight is periodically measured over the course of 500 hours. After test completion the relationship between ESR and weight loss is used to calculate the critical weight loss that occurs at datasheet-defined failure, which is typically a 200% increase in ESR. The rate of weight loss is extrapolated to the critical weight to estimate a time to failure that can be compared to other capacitors tested using the same accelerated approach. In this research, testing compared 450 V, 68 μF capacitors from Manufacturer A and Manufacturer B, and results indicated Manufacturer A had a significantly longer lifetime. Therefore, capacitors from Manufacturer A are more reliable than capacitors from Manufacturer B.

scholarly journals Reliability of X7R Multilayer Ceramic Capacitors During High Accelerated Life Testing (HALT)

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1900 ◽  
Author(s):  
Ana Hernández-López ◽  
Juan Aguilar-Garib ◽  
Sophie Guillemet-Fritsch ◽  
Roman Nava-Quintero ◽  
Pascal Dufour ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Time To Failure ◽  
Multilayer Ceramic Capacitors ◽  
Thermal Failure ◽  
Accelerated Life Tests ◽  
Accelerated Life ◽  
Essential Components ◽  
Ceramic Capacitors ◽  
Life Tests ◽  
Multilayer Ceramic

Multilayer ceramic capacitors (MLCC) are essential components for determining the reliability of electronic components in terms of time to failure. It is known that the reliability of MLCCs depends on their composition, processing, and operating conditions. In this present work, we analyzed the lifetime of three similar X7R type MLCCs based on BaTiO3 by conducting High Accelerated Life Tests (HALT) at temperatures up to 200 °C at 400 V and 600 V. The results were adjusted to an Arrhenius equation, which is a function of the activation energy (Ea) and a voltage stress exponent (n), in order to predict their time to failure. The values of Ea are in the range of 1–1.45 eV, which has been reported for the thermal failure and dielectric wear out of BaTiO3-based dielectric capacitors. The stress voltage exponent value was in the range of 4–5. Although the Ea can be associated with a failure mechanism, n only gives an indication of the effect of voltage in the tests. It was possible to associate those values with each type of tested MLCC so that their expected life could be estimated in the range of 400–600 V.

scholarly journals ESR Estimation Schemes of Output Capacitor for Buck Converter from Capacitor Perspective

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1596
Author(s):  
Lei Ren ◽  
Lei Zhang ◽  
Chunying Gong
Keyword(s):  
Buck Converter ◽  
Electrolytic Capacitor ◽  
Equivalent Series Resistance ◽  
Power Electronic Converters ◽  
Aluminum Electrolytic Capacitor ◽  
Advantages And Disadvantages ◽  
Optimal Period ◽  
Current Characteristics ◽  
Output Capacitor ◽  
Conduction Mode

The aluminum electrolytic capacitor (AEC) is one of the most vulnerable parts in power electronic converters and its reliability is crucial to the whole system. With the growth of service time, the equivalent series resistance (ESR) increases and the capacitance (C) decreases due to the loss of electrolytes, which will result in extra power loss and even damage to transistors. To prevent significant damages, the AEC must be replaced at an optimal period and online health monitoring is indispensable. Through the analysis of degradation parameters (ESR and C), ESR is proved to be a better health indicator and therefore is determined as the monitoring parameter for AEC. From the capacitor perspective, ESR estimation schemes of output capacitors for a Buck converter are studied. Based on the voltage–current characteristics, two ESR calculation models are proposed, which are applicable for both continuous conduction mode (CCM) and discontinuous conduction mode (DCM). From the point of implementation view, the advantages and disadvantages of the two estimation schemes are pointed out, respectively. A Buck prototype is built and tested, and simulation and experimental results are provided to validate the proposed ESR estimation schemes.

Reliability Assessment Based on Performance Parameter for Micro-Gyro

2014 ◽  
Vol 1037 ◽  
pp. 197-200
Author(s):  
Li Xia Yu ◽  
Li Qin ◽  
Meng Mei Wang
Keyword(s):  
High Reliability ◽  
Reliability Assessment ◽  
Assessment Method ◽  
Accelerated Life Test ◽  
Time To Failure ◽  
Accelerated Life ◽  
Parameter Measuring ◽  
Failure Life ◽  
Effective Assessment ◽  
Short Time

For high-reliability and long-lifetime product, it is difficult to assess the reliability with traditional accelerated life test that record only time to failure. Aiming to solve the problem of the previously, a reliability test and assessment method forecasting the life of samples based on degradation parameter was proposed. According to the working characteristic, the key parameter measuring performance degradation was selected. Based on statistical analysis methods, parameter degradation was designed and parameter degradation model was build. Combined with practical application background, the failure threshold was set and reliability assessment resultwas obtained. The method is applied to assessing reliability of micro gyroscope. The application shows that the method can achieve effective assessment, which can be used as similar products that are difficult to obtain the failure life data in a short time.

scholarly journals Accelerated competing risks model from Gompertz lifetime distributions with type-II censoring scheme

2020 ◽  
Vol 24 (Suppl. 1) ◽  
pp. 165-175
Author(s):  
Abdullah Almarashi ◽  
Gamal Abd-Elmougod
Keyword(s):  
Accelerated Life Test ◽  
Likelihood Method ◽  
Model Parameters ◽  
Test Model ◽  
Time To Failure ◽  
Type Ii ◽  
Type Ii Censoring ◽  
Accelerated Life ◽  
Interval Estimators ◽  
Censoring Scheme

Time to failure under normal stress conditions may take a long period of time and statistical inferences under this condition is more serious. Then, the experiment is loaded under stress higher than normal one which is defined as accelerated life tests. This problem in this paper is discussed in the form of partially step-stress accelerated life test model when the lifetime of the product has Gompertz lifetime distribution and unites are fails under the two independent risks. The maximum likelihood method under type-II censoring scheme is used to formulate the point and asymptotic confidence interval estimators of model parameters. The two boot?strap methods are also used to formulate the point and approximate interval estimators. The numerical results are adopted in the form of Monte Carlo studying to illustrate, assess and compare all of the theoretical results. Finally, results are discussed in points to clarify results validity.

Bearing life prognosis under environmental effects based on accelerated life testing

2002 ◽  
Vol 216 (5) ◽  
pp. 509-516 ◽  
Author(s):  
C Zhang ◽  
M T Le ◽  
B B Seth ◽  
S Y Liang
Keyword(s):  
Operating Conditions ◽  
Accelerated Life Testing ◽  
Model Verification ◽  
Accelerated Life Test ◽  
Experimental Result ◽  
Life Testing ◽  
Accelerated Life ◽  
Bearing Life ◽  
Stress Levels ◽  
Life Tests

The reliability of a bearing is typically estabilished by repeated life testing which provides valuable information on the fatigue mechanisms from crack initiation, crack propagation to flake or spall. Under nominal operating conditions, life testing often consumes a significant amount of time and resources, due to the comparatively high bearing mean lifetime before failure (MTBF), rendering the procedures expensive and impractical. Therefore, the technology of accelerated life testing (ALT), which is widely used in manufacturing practice, offers the attractive benefit of requiring relatively less investment in terms of time and resources. Data from tests at high stress levels (e.g. temperature, voltage, pressure, corrosive media, etc.) can be extrapolated, through a physically reasonable statistical model, to obtain life estimates at lower, normal stress levels. In this study, a methodology to predict bearing lifetime under a corrosive environment has been developed based on accelerated life testing data and the application of the inverse power law. Bearing life tests under various corrosion stress levels were performed for model identification followed by additional independent bearing life tests conducted for model verification. The experimental result shows that the accelerated life test model can effectively assess the life probability of a bearing based on accelerated environmental testing, even with extrapolation to untested stress levels.

Accelerated Reliability Methodologies for Electronic Components: A Case Study

2002 ◽  
Author(s):  
Nick Strifas ◽  
John Fraysse ◽  
Massimo Ruzzene
Keyword(s):  
Fiber Optic ◽  
Accelerated Life Test ◽  
Fiber Optic Sensor ◽  
Time To Failure ◽  
Electronic Components ◽  
Life Test ◽  
Life Distribution ◽  
Optic Sensor ◽  
Accelerated Life

The procedures of estimating the time to failure from accelerated test data are reviewed in this study. An accelerated life test approach which provides the desired reliability results for a fiber optic sensor in shorter times than would be possible with a test performed under normal stress conditions is presented. Utilizing ReliaSoft ALTA software the statistical and life distribution that describe the time to failure of the sensor is determined and the desired reliability results are calculated using the level probability density function.

scholarly journals A New Compromise Design Plan for Accelerated Failure Time Models with Temperature as an Acceleration Factor

Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 836
Author(s):  
Irene Mariñas-Collado ◽  
M. Jesús Rivas-López ◽  
Juan M. Rodríguez-Díaz ◽  
M. Teresa Santos-Martín
Keyword(s):  
Failure Time ◽  
Failure Process ◽  
Accelerated Life Test ◽  
Accelerated Failure Time ◽  
Time To Failure ◽  
Middle Point ◽  
Accelerated Life ◽  
Accelerated Failure Time Models ◽  
Accelerated Failure ◽  
Compromise Design

An accelerated life test of a product or material consists of the observation of its failure time when it is subjected to conditions that stress the usual ones. The purpose is to obtain the parameters of the distribution of the time-to-failure for usual conditions through the observed failure times. A widely used method to provoke an early failure in a mechanism is to modify the temperature at which it is used. In this paper, the statistically optimal plan for Accelerated Failure Time (AFT) models, when the accelerated failure process is described making use of Arrhenius or Eyring equations, was calculated. The result was a design that had only two stress levels, as is common in other AFT models and that is not always practical. A new compromise plan was presented as an alternative to the widely used “4:2:1 plan”. The three-point mixture design proposed specified a support point in the interval that was optimal for the estimation of the parameters in AFT models, rather than simply the middle point. It was studied in comparison to different commonly used designs, and it proved to have a higher D-efficiency than the others.

The Method for Estimating the Time to Failure in Accelerated Life Test

2013 ◽  
Vol 347-350 ◽  
pp. 129-132
Author(s):  
Zhong Zhen Chen ◽  
Lu Tie Xu
Keyword(s):  
Failure Time ◽  
Estimation Method ◽  
Time Estimation ◽  
Simulation Method ◽  
Accelerated Life Test ◽  
Time To Failure ◽  
Life Test ◽  
Test Range ◽  
Accelerated Life ◽  
Important Means

Accelerated life test was an important means to obtain storage reliability index of missile-borne photoelectric system. Because of difficulty to continuously test, the number of failure samples in the test range could be only got. Whether distribution intervals, logarithmic distribution or new failure time estimation method proposed in this paper such as range median distribution and the uniform distribution of the index had their applicable limitations. On the basis of comparison to Monte Carlo numerical simulation method, the characteristics of the applicability of the estimation method based on Weibull distribution were explored.

Aluminum electrolytic capacitors for tablet PC

2017 ◽  
Vol 31 (19-21) ◽  
pp. 1740011
Author(s):  
Longchun Liu ◽  
Liangwei Dong ◽  
Qinglong Li ◽  
Xiangyang Xu
Keyword(s):  
High Frequency ◽  
Temperature Stability ◽  
Operating Conditions ◽  
Electrolytic Capacitor ◽  
Tablet Pc ◽  
Durability Test ◽  
Aluminum Electrolytic Capacitor ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Aluminum Electrolytic Capacitors

Based on the operating conditions of tablet PC, this paper presents the design of a long load life aluminum electrolytic capacitor. Due to the key technology breakthrough of electrolyte with low resistance and excellent temperature stability, the capacitor boasts low leakage current, low impedance, high frequency, high ripple resistance and high temperature resistance. In the meantime, it can pass 5000 h of durability test with load at 105[Formula: see text]C. The aluminum electrolytic capacitor can be used in tablet PC with long load life.

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