ISSN:0748-8017    

DOI:10.1002/qre.4680060203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractA thermal model of double‐drift IMPATT diodes on diamond heat sinks has been developed. The thermal model approximates the temperature‐dependent thermal conductivities of Si and diamond (Type II) by means of simple empirical formulae. The application of the thermal model to three IMPATT diode lots indicates that under life test, junction temperatures are greater than 700°C, and that the metal/Si interface temperatures exceed 500°C. An explanation of the failure mechanism is presented. Designs that result in a lower junction temperature are pro

ISSN:0748-8017    

DOI:10.1002/qre.4680060204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThere is an evident lack of information about military‐type relays regarding their reliability, failure mechanisms and modes. In trying to fill this gap, even partially, this paper deals with different findings of internal visual inspection (IVI), failure analysis (FA) and a proposal for screening tests of relays as have been carried out in our laboratory. Likewise, it includes recommendations for quality assurance improvements. A special emphasis is placed on failure predictions by analysis of the IVI findings. This paper is based on a paper presented at the Seventh International Conference of the Israel Society for Quality Assurance (Tel‐Aviv, 8–10 November

ISSN:0748-8017    

DOI:10.1002/qre.4680060205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractLow‐power rectifier diodes were stressed by different forward currentsIF, reverse voltagesUR, and ambient temperaturesafor a time interval (0,t*) in order to analyse the resulting distributions. Owing to the limitations in the test time,t*, the gathering of comprehensive information about their performance requires high stress levels without exceeding either physical limits or the limits for initiating thermal runaway. First, the results of lifetime experiments related to the middle stress region were described by a Weibull distribution with constant shape parameter and stress‐dependent scale parameter. This model, however, did not fit sufficiently the typical features of the real‐life distribution. Therefore a non‐parametric measure called the average initial reliability in (O,t*) was defined using the experimental results. Its stress dependence was estimated. The results are guiding figures of stress conditions both for accelerated tests and for circuits with high demands on reli

ISSN:0748-8017    

DOI:10.1002/qre.4680060206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper discusses a dynamic histogram control chart which combines some ideas of histograms,Xcharts, zone charts and chi‐square charts. The chart is easy to use, easy to understand, and has quick response times. Another feature is that it does not require normal data asXcharts and zone charts do. The chart is especially useful for controlling processes with low data accumulation rates such as chemical processes or for controlling processes involving short runs such as job shop

ISSN:0748-8017    

DOI:10.1002/qre.4680060207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractMechanical equipment design demands a deep understanding of the inherent failure mechanisms likely to be encountered in service operation. Such understanding can result in the eradication or the limitation of the effects of in‐service failures. This aspect of engineering design is examined and a case study example, in which the design of stand‐by equipment involved the limitation of fretting corrosion, is used as an illustration of the general principles invol

ISSN:0748-8017    

DOI:10.1002/qre.4680060208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe use of Taguchi methods for parameter design and tolerance design is well established. This paper describes a new application to qualification trials or type approval tests. The essential difference from the accepted use is that the purpose is to demonstrate performance when a product is subjected to internal or external noise. With a tolerance trial the aim is to find which sources of noise can be cost‐effectively controlled. Two case‐study examples are presented which show the value of the technique. The first shows how the measurements are used to provide one of the published performance specifications for a digital electronic product. The second reveals how an interaction between three environmental parameters took an analogue electronic product out of specification. There is a discussion on the suitability of the technique for software testing and for reliability demonstrations. This includes comments on which arrays are most appropriate for which situat

ISSN:0748-8017    

DOI:10.1002/qre.4680060209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractUsing the example of stress tests for dielectric breakdown, the close relation between the local variation of defect density on the one hand and the area dependence of yield is verified directly.There is appreciable real variation of defect density (in addition to purely statistical fluctuation) even within individual wafers, but also additional variation between wafers processed together in groups and further variation again between groups of wafers processed separately. Correspondingly, the dependence of yield on area differs progressively more from the Poisson model as more (different) data are summarized in a single average yield.The local variation of defect density also depends on stress level, and hence on the defect considered.

ISSN:0748-8017    

DOI:10.1002/qre.4680060210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractResponse surface methodology (RSM) has long been recognized as an effective approach to empirical optimization of engineering processes. This paper reports a novel application of the methodology to enhance the efficiency and reliability of an active device alignment operation that is critical to fibreoptics manufacturing. With 22factorial designs, the RSM approach has been found capable of locating the optimum co‐ordinates for maximum power coupling at speeds more than three times those of the usual search algorithm

ISSN:0748-8017    

DOI:10.1002/qre.4680060211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

ISSN:0748-8017    

DOI:10.1002/qre.4680060212

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY