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Über dieses Buch

This book concentrates on the quality of electronic products. Electronics in general, including semiconductor technology and software, has become the key technology for wide areas of industrial production. In nearly all expanding branches of industry electronics, especially digital electronics, is involved. And the spread of electronic technology has not yet come to an end. This rapid development, coupled with growing competition and the shorter innovation cycle, have caused economic problems which tend to have adverse effects on quality. Therefore, good quality at low cost is a very attractive goal in industry today. The demand for better quality continues along with a demand for more studies in quality assurance. At the same time, many companies are experiencing a drop in profits just when better quality of their products is essential in order to survive against the competition. There have been many proposals in the past to improve quality without increase in cost, or to reduce cost for quality assurance without loss of quality. This book tries to summarize the practical content of many of these proposals and to give some advice, above all to the designer and manufacturer of electronic devices. It mainly addresses practically minded engineers and managers. It is probably of less interest to pure scientists. The book covers all aspects of quality assurance of components used in electronic devices. Integrated circuits (lCs) are considered to be the most important components because the degree of integration is still rising.

Inhaltsverzeichnis

Frontmatter

1. Introduction

Abstract
When valves were the active elements in electronic devices, their lifetime was so much less than the lifetime of all other components (like resistors or capacitors), that the quality of valves determined the quality of the device.
Werner Fleischhammer

2. Integrated quality assurance

Abstract
Quality assurance in the past was often an appendix to manufacturing. Its main task was to assure the quality of outgoing products by making measurements on attributive samples. These included accelerated life tests and tests under environmental stress like shock or aggressive atmosphere. It was up to management to interpret the results and decide whether corrective changes had to be made. This situation could never be very effective, because it resulted in curing bad quality instead of preventing it.
Werner Fleischhammer

3. Joint evaluation of all components

Abstract
As failure detection loses its prevailing importance, failure prevention comes into vogue, as stated in Table 3.1. The first step in failure prevention is the thorough evaluation of all new components. Evaluation means extended tests on a few samples of a component type as a first step towards its qualification. Due to the high complexity of modern electronic systems, high values of MTBF have to be realized. Therefore the importance of the qualification of electronic components is growing. This results from the fact that quality can only be improved when it is designed into the product. Therefore the goal for vendor and customer must be a joint qualification. The objective is, on the one hand, to avoid any duplication of work. The results of all characterization tests done by the vendor should be made available to the customer. The customer, on the other hand, should help the vendor to improve the components by transferring all the knowledge gained by evaluation and application back to the vendor. So a joint evaluation is indispensable to improving quality at a reasonable cost.
Werner Fleischhammer

4. Functional and electrical evaluation of digital ICs

Abstract
The first task when evaluating a component is to test all electrical properties: logic function, static parameters, dynamic parameters and some special properties. Because of the relatively small number of parts available for evaluation, no distributions or statistics are calculated; these are done later on incoming inspection. The purpose of evaluation is to obtain knowledge of all relevant properties of a component, even if these properties are not specified in the vendor’s data sheet. A thorough knowledge of all properties of all components is absolutely necessary to make a mature, faultless and safe design. Even if a design works without problems in a prototype, problems may occur later during production if there are any obscurities. So the results of evaluation tests are needed by the design engineers; and they are given by the evaluating engineers in form of application rules, or as recommendations.
Werner Fleischhammer

5. Reliability and environmental requirements

Abstract
The prediction of the reliability (failure rate) of electronic components is of great importance in designing electronic systems. The failure rate is affected by the inherent reliability of the components and by the operational and on-site environmental conditions.
Werner Fleischhammer

6. Quality assurance in the production phase

Abstract
The fast development of technology together with growing competition and shorter innovation cycles caused severe economic problems for the electronic industry. Cheaper products at the expense of consumer quality is by no means a promising response. Past experience shows that improving quality without increasing cost is a better way to compete. Chapter 3 showed how the quality of a product can be increased by better quality assurance in the pre-production phase.
Werner Fleischhammer

7. Design for quality, the key to good quality at low cost

Abstract
Logic design has been subjected to fundamental changes. Electronic devices are no longer designed on a breadboard with inevitable design errors eliminated tediously on prototypes. Today, logic design is computer aided, and both highly ICs and complete electronic systems are simulated immediately. Design errors are excluded by a great deal by simulation. In reality, no designer and no simulation is perfect, so failures will still be detected on prototypes. However, the number of redesigns at the prototype stage has dropped from as high as ten to one. This design method successfully reduced time to market. The author knows of one company which finished the design of a medium-scaled mainframe one year before the expected date on using the new design method for the first time. Other companies, according to the literature, had similar experiences. Time to market was shortened from 2–4 years to 1–2 years. This did not come without a struggle. At the beginning, engineers did not believe in the feasibility of a complete simulation. Management had to insist on it until its obvious success convinced all doubters.
Werner Fleischhammer

8. Specifications and standards as a basis for co-operation

Abstract
The preceding chapters have shown that efficient cost-saving quality assurance can only have been performed where there is strong cooperation between vendor and customer on the basis of mutual trust. This relationship has to be laid down in the form of a framework of specifications, which document the liabilities of both parties (Groh, 1993).
Werner Fleischhammer

Backmatter

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