Special Cases in Failure Analysis: Research on the Optimal Confidence Limit Evaluation by Zero-Failure Data

2020 ◽  
Vol 20 (5) ◽  
pp. 1638-1643
Author(s):  
Haiyang Li ◽  
Zeyu Zheng ◽  
Zihao Yang ◽  
Chen Xu
Author(s):  
Rommel Estores ◽  
Pascal Vercruysse ◽  
Karl Villareal ◽  
Eric Barbian ◽  
Ralph Sanchez ◽  
...  

Abstract The failure analysis community working on highly integrated mixed signal circuitry is entering an era where simultaneously System-On-Chip technologies, denser metallization schemes, on-chip dissipation techniques and intelligent packages are being introduced. These innovations bring a great deal of defect accessibility challenges to the failure analyst. To contend in this era while aiming for higher efficiency and effectiveness, the failure analysis environment must undergo a disruptive evolution. The success or failure of an analysis will be determined by the careful selection of tools, data and techniques in the applied analysis flow. A comprehensive approach is required where hardware, software, data analysis, traditional FA techniques and expertise are complementary combined [1]. This document demonstrates this through the incorporation of advanced scan diagnosis methods in the overall analysis flow for digital functionality failures and supporting the enhanced failure analysis methodology. For the testing and diagnosis of the presented cases, compact but powerful scan test FA Lab hardware with its diagnosis software was used [2]. It can therefore easily be combined with the traditional FA techniques to provide stimulus for dynamic fault localizations [3]. The system combines scan chain information, failure data and layout information into one viewing environment which provides real analysis power for the failure analyst. Comprehensive data analysis is performed to identify failing cells/nets, provide a better overview of the failure and the interactions to isolate the fault further to a smaller area, or to analyze subtle behavior patterns to find and rationalize possible faults that are otherwise not detected. Three sample cases will be discussed in this document to demonstrate specific strengths and advantages of this enhanced FA methodology.


Author(s):  
Alex Davila-Frias ◽  
Val Marinov ◽  
Om Prakash Yadav ◽  
Yuriy Atanasov

Abstract Accelerated life testing (ALT) has been a common choice to study the effects of environmental stresses on flexible hybrid electronics (FHE), a promising technology to produce flexible electronic devices. Nevertheless, accelerated degradation testing (ADT) has proven to be a more effective approach, which does not require failure occurrences, allowing shorter testing times. Since FHE devices are expected to be highly reliable, ADT provides useful information in the form of degradation data for further analysis without actual failure data. In this paper, we present the design and experimental setup of ADT for FHE considering two stress factors simultaneously. We use daisy-chain resistance as a measurable degradation characteristic to periodically monitor the degradation of FHE products under accelerated stress conditions. Two stress factors, temperature and humidity, are considered and ADT was carried out considering four combinations of temperature and humidity simultaneously. Failure analysis was performed on failed units to investigate the failure process and location of the failure. The ADT data was used to fit in the appropriate mathematical degradation model representing the failure process. The data analysis showed faster degradation paths for higher stress combinations. Finally, we present insights and further research opportunities to expand the work.


2017 ◽  
Vol Vol 159 (A1) ◽  
Author(s):  
D A Njumo

The main area of this work reflects a topic for which there is little or limited reference available and is carried out to meet the needs of professional and practical floating dry dock operators. The risk of hazards in floating dry docks is evaluated using a discrete fuzzy set theory (FST) and an evidential reasoning (ER) approach in a situation where historical failure data is not available. Fuzzy set modelling is used to estimate the safety levels of the causes of basic failure events in floating dry docks due to stability concerns using the concept of linguistic variables, and provides a framework for dealing with such variables in a systematic way. The ER approach is used to synthesise the estimated safety levels of the causes of hazards/basic hazard events. The results of this work will be valuable to dry dock masters and sister maritime engineering professionals.


2010 ◽  
Vol 37-38 ◽  
pp. 939-943 ◽  
Author(s):  
Yi Qiang Wang ◽  
Xiao Jun Wang ◽  
Shun Ming Hua

An automatic tool changer (ATC) is one of the most important subsystems of a computerized numerical control (CNC) lathe. The field failure analysis is very important to improve the reliability of the ATC. The structure and mechanism of an ATC is briefly introduced. Its brief reliability block diagram is set up. With this understanding, through the collection of the field failure data, a coding system to code failure data is devised and a failure analysis database of CNC lathes is accrued. The failure mode and cause are analyzed to indicate the weak subsystem of the ATC. Some suggestions on improving the reliability have been proposed.


1980 ◽  
Vol 15 (1) ◽  
pp. 43-49 ◽  
Author(s):  
G J Turvey

An exact solution of the strip equilibrium equations is combined with the Tsai-Hill failure criterion to facilitate an initial flexural failure analysis of uniformly-loaded, antisymmetrically-laminated, GFRP and CFRP angle-ply strips. Dimensionless, initial-failure data (that is, failure loads and their associated strip centre-line deflections) are presented for the practical range of fibre orientations, 15° ≤|θ| ≤ 75°, in strips comprising up to ten laminae.


Author(s):  
G K Cole

Statistical failure analysis of aero gas turbines presents many special problems. Various difficulties must be overcome, including the paucity and form of available data with its heavily censored nature, selecting the right analysis method, the validity of the underlying modelling assumptions and the correct interpretation of the results. This paper outlines the formal Rolls-Royce approach to quantifying numerical risk for safety and reliability, and the pivotal role played by the Weibull distribution. It reviews the generic forms of the censored failure data obtained from test and service environments. The limitations of the current analysis techniques are reviewed.


Author(s):  
D A Njumo

The main area of this work reflects a topic for which there is little or limited reference available and is carried out to meet the needs of professional and practical floating dry dock operators. The risk of hazards in floating dry docks is evaluated using a discrete fuzzy set theory (FST) and an evidential reasoning (ER) approach in a situation where historical failure data is not available. Fuzzy set modelling is used to estimate the safety levels of the causes of basic failure events in floating dry docks due to stability concerns using the concept of linguistic variables, and provides a framework for dealing with such variables in a systematic way. The ER approach is used to synthesise the estimated safety levels of the causes of hazards/basic hazard events. The results of this work will be valuable to dry dock masters and sister maritime engineering professionals.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Haiyang Li ◽  
Zeyu Zheng

Due to the improvement of the quality of industrial products, zero-failure data often occurs during the reliability life test or in the service environment, and such problems cannot be handled using traditional reliability estimation methods. Regarding the processing and analysis of zero-failure data, the confidence limit assessment methods were proposed by some researchers. Based on the existing research, a confidence limit method set (CLMS) is established in the Weibull distribution for reliability estimation of zero-failure data. The method set includes the unilateral confidence limit method and optimal confidence limit method, so that almost all existing grouping types of zero-failure data can be quickly evaluated, and multiple methods can be used in parallel to deal with the same problem. The effectiveness and high efficiency of the CLMS combined with numerical simulation examples have been verified, and the possibility of analyzing multiple groups of zero-failure data with a confidence limit method suitable for processing single group of zero-failure data is expanded. Finally, the actual effect of the method set is verified by the single group of zero-failure data of rolling bearings and the multiple groups of zero-failure data of torque motors. The results of the example evaluation show that the CLMS has obvious advantages in practical engineering applications.


2021 ◽  
Vol 11 (3) ◽  
pp. 1249
Author(s):  
Shizheng Li ◽  
Zhaojun Yang ◽  
Hailong Tian ◽  
Chuanhai Chen ◽  
Yongfu Zhu ◽  
...  

A hydraulic system is a key subsystem of heavy-duty machine tools with a high failure intensity, the failure of which often causes shutdown of production and economic loss in machining. Therefore, it is necessary to implement failure analysis to identify the weak links of system and improve the reliability. For hydraulic system, there is often an amount of failure data collected in field, which help to calculate the occurrence probability of basic events through fault tree analysis method. However, the data are incomplete and uncertain. To address this issue, this study presents a fault tree analysis methodology. Experts’ opinions are utilized, combined with field data based on the Dempster–Shafer theory and rough set theory to fill the incompleteness and eliminate the uncertainty. For application in a case study, a fault tree of the hydraulic system of heavy-duty machine tools is firstly constructed. Then, the importance analysis is performed to help identify the weak links of hydraulic system. The results show the critical basic events affecting the safety and reliability of a hydraulic system.


Author(s):  
Jean-Yves Glacet ◽  
Fourmun Lee

Abstract SRAM bitmapping and failure analysis have been used as a driver for continuous yield improvement during pre-qualification manufacturing of a microcontroller. The combination of the embedded SRAM electrical failure data and failure analysis results was used to generate a pareto of failure modes and failure mechanisms and establish a correlation between the two. Bitmap trend charts can be used as a manufacturing line monitoring tool to supplement traditional in-line inspection. Identification of manufacturing issues can be obtained from bit failure information and compared with in-line inspection results to quickly identify which specific process module is responsible for a significant yield loss.


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