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1 – 10 of over 61000C. Pusarla, A. Dasgupta, M.G. Pecht and A. Christou
This paper presents an application of the physics‐of‐failure design philosophy to flip‐chip bonds in a microelectronic package. The physics‐of‐failure philosophy utilises…
Abstract
This paper presents an application of the physics‐of‐failure design philosophy to flip‐chip bonds in a microelectronic package. The physics‐of‐failure philosophy utilises knowledge of the life‐cycle load profile, package architecture and material properties to identify potential failure mechanisms and to prevent operational failures through robust design and manufacturing practices. The potential failure mechanisms and failure sites are identified in this paper for flip‐chip bonds, and an approach is presented to prevent the identified potential failure mechanisms by design. Finally, quality conformance issues are discussed to ensure a robust manufacturing process and qualification issues are addressed to evaluate the reliability of the designed flip‐chip bond.
Liyu Yang and Joseph Bernstein
The purpose of this paper is to describe key failure mechanisms observed during the development of the advanced packaging technology. Extensive accelerated stress tests are…
Abstract
Purpose
The purpose of this paper is to describe key failure mechanisms observed during the development of the advanced packaging technology. Extensive accelerated stress tests are conducted to collect failure data and understand failure characteristics and failure trends. The results will be useful for design improvement and failure rate predictions.
Design/methodology/approach
High density chip scale packages (CSP) are developed to meet the needs for high performance and small form‐factor products, but with reduced process procedures and product cost. Test‐to‐failure approaches are applied to evaluate the failure rate and reliability models instead of compliance qualification testing approaches.
Findings
The study shows Cu‐trace cracking failure can be treated as random failures and analyzed using a constant failure rate approach. The acceleration factor for the Cu‐trace cracking failure mechanism exhibits a large power exponent comparing to the parameters used in reference models. In addition, the solder joint failure data collected through the study do not fit well with the well‐known solder fatigue life model. Moreover, the test results affirm the test‐to‐failure approach adopted in data collection is providing more accurate failure characteristics compared to the compliance qualification testing approach.
Practical implications
The paper shows that the reliability performance of package technology can be improved by enhancing the package design, improving manufacturing processes and materials optimization.
Originality/value
This is an original research paper and the test‐to‐failure approach in the reliability study helps provide realistic reliability predictions.
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Chengfu Hu, Chong Shi, Yiping Zhang, Xiao Chen and Sha Luo
Cemented conglomerate accumulation is a weak and heterogeneous medium that occurs in western China. It consists mainly of argillaceous cement that loses strength rapidly upon…
Abstract
Purpose
Cemented conglomerate accumulation is a weak and heterogeneous medium that occurs in western China. It consists mainly of argillaceous cement that loses strength rapidly upon contact with water, leading to collapse instability failure. Its deformation failure mechanism is complex and poorly understood. In this paper, the erosion failure mechanism of cemented conglomerate accumulation is investigated.
Design/methodology/approach
The collapse failure process after erosion of the slope foot for typical cemented conglomerate accumulation is studied based on field investigation using the particle discrete element method. And how the medium composition, slope angle and cementation degree influence the failure mode and process of the cemented conglomerate accumulation is examined.
Findings
The foot erosion of slope induces a tensile failure that typically manifests as “erosion at the foot of slope – tensile cracking at the back edge of slope top – integral collapse.” The collapse failure is more likely to occur when the cemented conglomerate accumulation has a higher rock content, a steeper slope angle or a weaker cementation degree.
Originality/value
A model based on rigid blocks and disk particles to simulate the cemented conglomerate accumulation is developed. It shows that the hydraulic erosion at the foot of the slope resulted in a different failure mechanism than that of general slopes. The results can inform the stability management, disaster prevention and mitigation of similar slopes.
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J.W. Morris, D. Grivas, D. Tribula, T. Summers and D. Frear
This paper discusses the microstructures of solder joints and the mechanism of thermal fatigue, which is an important source of failure in electronic devices. The solder joints…
Abstract
This paper discusses the microstructures of solder joints and the mechanism of thermal fatigue, which is an important source of failure in electronic devices. The solder joints studied were near‐eutectic Pb‐Sn solder contacts on copper. The microstructure of the joints is described. While the fatigue life of near‐eutectic solder joints is strongly dependent on the operating conditions and on the microstructure of the joint, the metallurgical mechanisms of failure are surprisingly constant. When the cyclic load is in shear at temperatures above room temperature the shear strain is inhomogeneous, and induces a rapid coarsening of the eutectic microstructure that concentrates the deformation in well‐defined bands parallel to the joint interface. Fatigue cracks propagate along the Sn‐Sn grain boundaries and join across the Pb‐rich regions to cause ultimate failure. The failure occurs through the bulk solder unless the joint is so thin that the intermetallic layer at the interface is a significant fraction of the joint thickness, in which case failure may be accelerated by cracking through the intermetallic layer. The coarsening and subsequent failure are influenced more strongly by the number of thermal cycles than by the time of exposure to high temperature, at least for hold times up to one hour. Thermal fatigue in tension does not cause well‐defined coarsened bands, but often leads to rapid failure through cracking of the brittle intermetallic layer. Implications are drawn for the design of accelerated fatigue tests and the development of new solders with exceptional fatigue resistance.
Abdulnaser Ibrahim Nour, Mohammad Najjar, Saed Al Koni, Abullateef Abudiak, Mahmoud Ibrahim Noor and Rani Shahwan
The purpose of this research is to examine the impact of governance mechanisms on corporate failure.
Abstract
Purpose
The purpose of this research is to examine the impact of governance mechanisms on corporate failure.
Design/methodology/approach
This study used a hypothesis-testing research design to collect data from the annual reports of 35 companies listed on Palestine Exchange from 2010 to 2019. Descriptive and inferential statistics were employed, along with correlation analysis to evaluate linear relationships between variables. The variance inflation factor was used to test multicollinearity, and binary logistic regression was utilized to develop the research model.
Findings
There is a significant positive relationship between board of directors' independency, institutional ownership and the quality of external audit, and corporate failure reduction. No significant relationship has been found among corporate governance variables such as board size, board meetings' frequency, board members' remuneration and audit committee existence, and corporate failure reduction.
Research limitations/implications
Several empirical research studies have developed models to predict corporate failure using accounting and financial data. However, limited research has empirically investigated the impact of the different mechanisms of governance on corporate failure prediction.
Practical implications
The research highlighted the significance of companies' commitment to governance principles and their impact on predicting failure. The study suggests that decision-makers and managers can adopt different governance mechanisms to support corporate success and avoid those that may lead to negative consequences and failure.
Originality/value
This research is the first in Palestine to use a comprehensive list of corporate governance mechanisms to predict the failure of companies listed on the Palestine Stock Exchange between 2010 and 2019.
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Amar Messas, Karim Benyahi, Arezki Adjrad, Youcef Bouafia and Sarah Benakli
The purpose of this study, is to deals with capacity design (strong column – weak beam) in reinforced concrete frames, slightly slender, which depends on the determination of a…
Abstract
Purpose
The purpose of this study, is to deals with capacity design (strong column – weak beam) in reinforced concrete frames, slightly slender, which depends on the determination of a capacity ratio necessary to reach a structural plastic mechanism. To find the capacity ratio allowing to achieve a fairly ductile behavior in reinforced concrete frames, it is necessary to validate this concept by a non-linear static analysis (push-over). However, this analysis is carried out by the use of the ETABS software, and by the introduction into the beams and columns of plastic hinges according to FEMA-356 code.
Design/methodology/approach
This approach makes it possible to assess seismic performance, which facilitates the establishment of a system for detecting the plasticization mechanisms of structures. It is also necessary to use a probabilistic method allowing to treat the dimensioning by the identification of the most probable mechanisms and to take only those that contribute the most to the probability of global failure of the structural system.
Findings
In this study, three reinforced concrete frame buildings with different numbers of floors were analyzed by varying the capacity ratio of the elements. The results obtained indicate that it is strongly recommended to increase the ratio of the resistant moments of the columns on those of the beams for the Algerian seismic regulation (RPA code), knowing that the frameworks in reinforced concrete are widespread in the country.
Originality/value
The main interest of this paper is to criticize the resistance condition required by RPA code, which must be the subject of particular attention to reach a mechanism of favorable collapse. This study recommends, on the basis of a reliability analysis, the use of a capacity dimensioning ratio greater than or equal to two, making it possible to have a sufficiently low probability of failure to ensure a level of security for users.
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Fei-Jun Chen, Shi Yan and Zhen-Guo Yang
The purpose of this study is to address two kinds of printed circuit board (PCB) failures with electrolytic Ni/Au as the surface finish. One was the weak bondability of gold wires…
Abstract
Purpose
The purpose of this study is to address two kinds of printed circuit board (PCB) failures with electrolytic Ni/Au as the surface finish. One was the weak bondability of gold wires to Ni/Au pads and the other was “dull gold” and weak solder wettability, which both caused great loss for the PCB manufacturer.
Design/methodology/approach
The failure samples were studied and analyzed in terms of macro- and micro-morphology of the surface finish, its element composition and thickness by various characterization techniques, such as three-dimensional stereo microscope, scanning electron microscope, energy dispersive spectroscopy and X-ray fluorescence spectrum.
Findings
Then the causes of the two failures were both found to be the inadequate thickness of gold deposit and other surface finish defects, but these causes played different roles in either failure or the mechanisms differ. Finally, their failure mechanisms were discussed and corresponding countermeasures were put forward for prevention.
Practical implications
This study not only addresses a practical failure problem but also provides some clues to a better and further understanding of the effect of PCB process and management on its quality and reliability in manufacturing practice.
Originality/value
It sheds light on how the thickness and quality of surface finish affects its wire bonding and soldering performances.
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– The purpose of this study is to explore the dependence of material properties and failure criteria for fused deposition modeling (FDM) polycarbonate on raster orientation.
Abstract
Purpose
The purpose of this study is to explore the dependence of material properties and failure criteria for fused deposition modeling (FDM) polycarbonate on raster orientation.
Design/methodology/approach
Tension, hardness and density measurements were conducted on a range of specimens at raster angles between 0 and 90° at 15° intervals. Specimens were manufactured so the raster angle was constant throughout each specimen (no rotation between adjacent layers). The yield strength, tensile strength, per cent elongation, elastic modulus, hardness and density of the material were measured as a function of raster angle. The orientation dependence of the properties was then analyzed and used to motivate a failure mechanism map for the material.
Findings
The properties of the material were found to be highly orientation-dependent. The variations in mechanical properties were explained to first order using a failure mechanism map similar to those generated for fiber-reinforced composites.
Originality/value
In addition to providing valuable experimental data for FDM polycarbonate, the study proposes micro-mechanisms of failure that appear to explain and capture the angular variation of strength with raster orientation. The fact that analysis methods which have been used for composites appear to apply to FDM materials suggests rich areas for future exploration.
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Johanna Virkki, Lauri Sydänheimo and Pasi Raumonen
Accelerated tests are commonly used to evaluate the reliability of electronic components and to detect failures caused by environmental conditions in field use. Many standard…
Abstract
Purpose
Accelerated tests are commonly used to evaluate the reliability of electronic components and to detect failures caused by environmental conditions in field use. Many standard accelerated tests are available for evaluating the reliability in a commonly approved way. These tests form a good basis for reliability testing. However, sometimes standard accelerated tests may not be directly used to test the reliability of a certain component. Rather, such tests should be modified for each component, based on the component's structure and field use. The purpose of this paper was to modify two Joint Electron Device Engineering Council (JEDEC) standard accelerated tests: the steady‐state temperature humidity‐bias life test (the 85/85 test) and the temperature cycling test, for use in testing tantalum capacitors more efficiently.
Design/methodology/approach
The 85/85 test was first modified by adding a ripple voltage and then by adding a voltage off‐period. The temperature cycling test was modified by using applied voltage during the test and then by shortening the testing time.
Findings
Standard accelerated tests form a good basis for reliability testing, but accelerated tests should be carefully planned and tailored for each component type, based on structure and conditions of use. Results show that, with minor modifications, standard tests can be diversified into various types of tests.
Research limitations/implications
Conclusions are mostly based on a literature review. More testing needs be undertaken in order to collect statistical data to validate the conclusions.
Originality/value
The objective in this paper was to produce more versatile tests for tantalum capacitors, based on two JEDEC standard accelerated tests. The developed tests can help detect failure mechanisms of tantalum capacitors faster and more accurately than standard accelerated tests.
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Saskia M. de Theije, Peter C. Sander and Aarnout C. Brombacher
Because of the importance of the product design process, a good control of it is of vital importance. It is shown how design tests can be defined and executed that are able to…
Abstract
Because of the importance of the product design process, a good control of it is of vital importance. It is shown how design tests can be defined and executed that are able to identify quality problem. Emphasis will be on the early detection of reliability problems. The quality control method itself and the results reached at Philips Electronics Industries‐Consumer Electronics Division (PEI‐CED) in Taiwan will be discussed. First, the organisation of a design process and design reliability evaluation program in general will be considered. Next, it will be explained what opportunities for improvement of reliability control in the design process at PEI‐CED were detected. A risk analysis, aimed at identifying reliability risks and analysing them, will be the basis for the reliability tests that will be elaborated next.
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