The Failure Analysis Process

2012 ◽  
pp. 549-583

Abstract This chapters discusses the basic steps in the failure analysis process. It covers examination procedures, selection and preservation of fracture surfaces, macro and microfractography, metallographic analysis, mechanical testing, chemical analysis, and simulated service testing.

Author(s):  
Steve Ferrier ◽  
Kevin D. Martin ◽  
Donald Schulte

Abstract Application of a formal Failure Analysis metaprocess to a stubborn yield loss problem provided a framework that ultimately facilitated a solution. Absence of results from conventional failure analysis techniques such as PEM (Photon Emission Microscopy) and liquid crystal microthermography frustrated early attempts to analyze this low-level supply leakage failure mode. Subsequently, a reorganized analysis team attacked the problem using a specific toplevel metaprocess.(1,a) Using the metaprocess, analysts generated a specific unique step-by-step analysis process in real time. Along the way, this approach encouraged the creative identification of secondary failure effects that provided repeated breakthroughs in the analysis flow. Analysis proceeded steadily toward the failure cause in spite of its character as a three-way interaction among factors in the IC design, mask generation, and wafer manufacturing processes. The metaprocess also provided the formal structure that, at the conclusion of the analysis, permitted a one-sheet summary of the failure's cause-effect relationships and the analysis flow leading to discovery of the anomaly. As with every application of this metaprocess, the resulting analysis flow simply represented an effective version of good failure analysis. The formal and flexible codification of the analysis decision-making process, however, provided several specific benefits, not least of which was the ability to proceed with high confidence that the problem could and would be solved. This paper describes the application of the metaprocess, and also the key measurements and causeeffect relationships in the analysis.


Author(s):  
DongHoon Choi ◽  
Jae-Hoon Kim

Mobile elevating work platforms (MEWPs) consist of a work platform, extending structure, and chassis, and are used to move persons to working positions. MEWPs are useful but are composed of pieces of equipment, and accidents do occur owing to equipment defects. Among these defects, accidents caused by the fracture of bolts fixed to the extension structure and swing system are increasing. This paper presents a failure analysis of the fixing bolts of MEWP. Standard procedure for failure analysis was employed in this investigation. Visual inspection, chemical analysis, tensile strength measurement, and finite element analysis (FEA) were used to analyze the failure of the fixing bolts. Using this failure analysis approach, we found the root cause of failure and proposed a means for solving this type of failure in the future. First, the chemical composition of the fixing bolt is obtained by a spectroscopy chemical analysis method, which determined that the chemical composition matched the required standard. The tensile test showed that the tensile and yield strengths were within the required capacity. The stress analysis was carried out at five different boom angles, and it was determined that the fixing bolt of MEWP can withstand the loads at all the boom angles. The outcomes of the fatigue analysis revealed that the fixing bolt fails before reaching the design requirements. The results of the fatigue analysis showed primarily that the failure of the fixing bolt was due to fatigue. A visual inspection of the fractured section of the fixing bolt also confirmed the fatigue failure. We propose a method to prevent failure of the fixing bolt of the MEWP from four different standpoints: the manufacturer, safety certification authority, safety inspection agency, and owner.


Author(s):  
Reinaldo Lucas dos Santos Rosa ◽  
Antonio Carlos Seabra

This chapter provides a guide for microfluidic devices development and optimization focused on chemical analysis applications, which includes medicine, biology, chemistry, and environmental monitoring, showing high-level performance associated with a specific functionality. Examples are chemical analysis, solid phase extraction, chromatography, immunoassay analysis, protein and DNA separation, cell sorting and manipulation, cellular biology, and mass spectrometry. In this chapter, most information is related to microfluidic devices design and fabrication used to perform several steps concerning chemical analysis, process preparation of reagents, samples reaction and detection, regarding water quality monitoring. These steps are especially relevant to lab-on-chip (LOC) and micro-total-analysis-systems (μTAS). μTAS devices are developed in order to simplify analytical chemist work, incorporating several analytical procedures into flow systems. In the case of miniaturized devices, the analysis time is reduced, and small volumes (nL) can be used.


2013 ◽  
Vol 804 ◽  
pp. 333-336
Author(s):  
Yun Jian Jiang ◽  
Xiang Feng Zheng ◽  
Rong Gang Xue ◽  
Guo Zhen Dong ◽  
Ji Feng Zhao ◽  
...  

Through methods, such as microscope analysis, chemical analysis, metallography examination and scanning electron microscope etc, the causes resulting in high temperature reheater tube cracking of station boiler have been analyzed. The result indicates the crack is reheat crack, and structure stress, higher hardness and excessive welding residual stress are the primary inducement of tube joint crack.


2011 ◽  
Vol 301-303 ◽  
pp. 989-994
Author(s):  
Fei Wang ◽  
Da Wang ◽  
Hai Gang Yang

Scan chain design is a widely used design-for-testability (DFT) technique to improve test and diagnosis quality. However, failures on scan chain itself account for up to 30% of chip failures. To diagnose root causes of scan chain failures in a short period is vital to failure analysis process and yield improvements. As the conventional diagnosis process usually runs on the faulty free scan chain, scan chain faults may disable the diagnostic process, leaving large failure area to time-consuming failure analysis. In this paper, a SAT-based technique is proposed to generate patterns to diagnose scan chain faults. The proposed work can efficiently generate high quality diagnostic patterns to achieve high diagnosis resolution. Moreover, the computation overhead of proving equivalent faults is reduced. Experimental results on ISCAS’89 benchmark circuits show that the proposed method can reduce the number of diagnostic patterns while achieving high diagnosis resolution.


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