Two life prediction models for optoelectronic displays without conventional life tests.

Abstract

To precisely predict the life of optoelectronic displays over a short time, two life prediction models were established based on the three-parameter Weibull right approximation method (TPWRAM). In Model I, the acceleration life under each stress was obtained using TPWRAM, the data points formed by acceleration life and acceleration stress were, respectively, fitted by three extrapolation functions and the optimal extrapolation function was determined by comparing the fitting determination coefficient and root-mean-square error. In Model II, after introducing an acceleration parameter, the luminance attenuation data under conventional stress were calculated directly by combining the ones obtained using TPWRAM under each acceleration stress. The luminance attenuation test data from the vacuum fluorescent display (VFD) were collected through four groups of constant-stress accelerated degradation tests (ADT), and the two models were applied to the life prediction of VFD. The results indicated that the designed ADT scheme was feasible, Model I revealed the changing law of life with stress and simplified the process of life prediction, and Model II made it possible to obtain the luminance attenuation formula at conventional stress without conducting a conventional life test, overcoming the shortcomings of long time-consuming traditional life tests. It was verified by comparing the life prediction values that the two models had very high precision, and both of these not only achieve the accurate estimation of optoelectronic product life without resorting to conventional life test, but also improved the method of life prediction and perfect its theoretical system.