Inspection and failure analysis

Gitis N, Vinogradov M. Incoming inspection and failure analysis of CMP consumables at the semiconductor fab. VMIC Conference Santa Clara, CA 2003. 

ASM Handbook. ASM International http //products.asmintemational.org/hbk/index.jsp (accessed March 27, 2011). The ASM Handbook comprises 21 volumes providing major reference information to industry about mining extraction, metallurgical processing and fabrication of metals testing, inspection, and failure analysis microstructural analysis and materials characterization corrosion, and wear phenomena in machinery and eqnipment, some of it used in the mining industry. 

Modem industrial facilities usually are equipped with systems that form the foimdation for the second requirement. Historical inspection data, failure analysis reports, analytical chemistry records, databases of operational parameters, and maintenance management systems are usually in place. The main task, therefore, is one of combining and integrating corrosion data into these existing (computerized) systems. In many organizations, much of the technical infrastructure required for achieving corrosion process control is already in place. Only the addition of certain corrosion-specific elements to existing systems may be needed. 

In the simplest terms, a fault-tree for risk analysis requires the following information probabiUty of detection of a particular anomaly for an NDE system, repair or replacement decision for an item judged defective, probabiUty of failure of the anomaly, cost of failure, cost of inspection, and cost of repair. Implementation of a risk-based inspection system should lead to an overall improvement in the inspection costs as well as in the safety in operation for a plant, component, or a system. Unless the database is well estabUshed, however, costs may fluctuate considerably. 

Visual inspection techniques are stressed as the most important tools used to study failures. This text is not a substitute for rigorous failure analysis conducted by experts, but it will help the reader identify and eliminate many cooling water system problems. Still, on occasion, the experienced, skilled, failure analyst using sophisticated analytical techniques and specialized equipment may be required to solve complex or unusual problems. Common sense, appropriate experience, and systematic investigation are, however, often superior to the more elaborate, but less effective, techniques used by some. 

This report evaluates recent performance of DGs and all DG vendors with the exception of Transamerica Delaval, Inc. (TDl), because of the emphasis already being given to TDI diesels in other studies. For the period 1980 through 1983 inclusive, BNL reviewed and evaluated DG failure data, DG vendor inspection reports, the TDI lessons learned as they related to the other vendors, and previous pertinent studies. The data sources used for DG failure analysis were LERs, 10 CFR 50.55E, Part 21, NPRDS, and EPRI document files. The DG failures were classified relative to the DG component that failed (e.g., main bearings, starting system). The failures were also categorized and analyzed by mode, manufacturer, and cause. Manufacturers with significant failures are identified in the report. 

The acoustic microscopy s primary application to date has been for failure analysis in the multibillion-dollar microelectronics industry. The technique is especially sensitive to variations in the elastic properties of semiconductor materials, such as air gaps. SAM enables nondestructive internal inspection of plastic integrated-circuit (IC) packages, and, more recently, it has provided a tool for characterizing packaging processes such as die attachment and encapsulation. Even as ICs continue to shrink, their die size becomes larger because of added functionality in fact, devices measuring as much as 1 cm across are now common. And as die sizes increase, cracks and delaminations become more likely at the various interfaces. 

An Instron tensile machine can be used to measure stress and strain in the automotive lab. However, incoming inspection at a supplier is generally where this type of analysis takes place. More often, an automotive chemist at an OEM will be required to analyze a sample for failure analysis of that particular part. A thermogravimetric analyzer (TGA) will measure the change in mass of an elastomer in an inert (nitrogen) atmosphere as the temperature is waived. These instruments are very precise and will give information such as degradation temperature, filler content solvent residue, and absorbed moisture content. 

Before we can define the mission for any particular test or inspection system we must be able to specify customer needs. While a detailed framework for designing inspection systems is given in Section 7, we must consider now how to define such needs. One way is to apply a failure modes and effects analysis (FMEA) to the product and design a test and evaluation system to cover each of the potential failure modes. But this technique does not make the customer an explicit part of the design process, whereas we have seen earlier (Section 1) that direct customer input is increasingly needed in more customized products. A preferable technique is to begin with customer function and quality requirements as the basis for a list of product attributes that form the basis of test and inspection. In attributes inspection (Section 2.1), this list is often a defect list or fault list defining the discrete defects that the inspection system must ensure the customer never experiences. 

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