Optimum Accelerated Life Tests Wth a Nonconstant Scale Parameter

Previous work on planning accelerated life tests has assumed that the scale parameter σ for a location-scale distribution of log lifetime remains constant over all stress levels. This assumption is, however, inappropriate for many applications, including accelerated tests for metal fatigue and certain electronic components. This article extends the existing maximum likelihood theory for test planning to the nonconstant σ model and presents test plans for a large range of practical testing situations. The test plans are optimum in that they minimize the asymptotic variance of the maximum likelihood estimator of a specified quantile at the design stress. The development and discussion in the article, as well as the theory given in the Appendix, applies to accelerated-life-test models in which the log time-to-failure can be modeled as a location-scale distribution. The test setup assumes simultaneous testing of units with time censoring. We give particular numerical results for the Weibull failure-time distr...

[1]  P. C. Li,et al.  Time-dependent dielectric breakdown of chemical-vapour-deposited SiO/sub 2/ gate dielectrics , 1989 .

[2]  D. J. Klinger,et al.  Failure time and rate constant of degradation: An argument for the inverse relationship , 1992 .

[3]  K. Chaloner,et al.  Bayesian design for accelerated life testing , 1992 .

[4]  W. Meeker.  Accelerated Testing: Statistical Models, Test Plans, and Data Analyses , 1991 .

[5]  William Q. Meeker,et al.  Theory for Optimum Accelerated Censored Life Tests for Weibull and Extreme Value Distributions , 1978 .

[6]  A. Spitzer,et al.  Lifetime of thin oxide and oxide-nitride-oxide dielectrics within trench capacitors for DRAMs , 1989 .

[7]  William Q. Meeker,et al.  Fisher Information Matrix for the Extreme Value, Normal and Logistic Distributions and Censored Data , 1994 .

[8]  W. Meeker.  A Comparison of Accelerated Life Test Plans for Weibull and Lognormal Distributions and Type I Censoring , 1984 .

[9]  Ronald E. Glaser,et al.  Estimation for a weibull accelerated life testing model , 1984 .

[10]  J. A. Schwarz.  Effect of temperature on the variance of the log‐normal distribution of failure times due to electromigration damage , 1987 .

[11]  Russell R. Barton.  Optimal accelerated life-time plans that minimize the maximum test-stress , 1991 .

[12]  C. Chan,et al.  Temperature-dependent standard deviation of log(failure time) distributions , 1991 .

[13]  H.-U. Schreiber,et al.  Electromigration measuring techniques for grain boundary diffusion activation energy in aluminum , 1981 .

[14]  William Q. Meeker,et al.  Optimum Accelerated Life-Tests for the Weibull and Extreme Value Distributions , 1975, IEEE Transactions on Reliability.

[15]  R. L. Hartman,et al.  Methodology of accelerated aging , 1985, AT&T Technical Journal.

[16]  J. McPherson,et al.  Acceleration Factors for Thin Gate Oxide Stressing , 1985, 23rd International Reliability Physics Symposium.

[17]  Herman Chernoff,et al.  Optimal Accelerated Life Designs for Estimation , 1962 .

[18]  W. Meeker,et al.  Accuracy of approx confidence bounds using censored Weibull regression data from accelerated life tests , 1990 .

[19]  Wayne Nelson,et al.  Optimum Censored Accelerated Life Tests for Normal and Lognormal Life Distributions , 1975 .

[20]  L. E. Felton,et al.  Compensating effects in electromigration kinetics , 1985 .

[21]  Thomas J. Kielpinski,et al.  Optimum Censored Accelerated Life Tests for Normal and Lognormal Life Distributions , 1975, IEEE Transactions on Reliability.

[22]  W Nelson,et al.  Fitting of fatigue curves with nonconstant standard deviation to data with runouts , 1984 .

[23]  K. C. Boyko,et al.  Time Dependent Dielectric Breakdown of 210? Oxides , 1989 .