In Auburngrads/SMRD: Statistical Methods For Reliability Data

Example 1.2 - Integrated Circuit Life Test (Meeker, 1987)

• Motivation for the study

  • Company 'A' is shipping products with defective integrated circuits (IC)

  • The company wants to ID which products contain defective IC's and remove them from the population of items to be shipped

  • Identifying the defective products requires testing them to simulate their first year of operation (process called burn-in)

  • Very little time is available to conduct the burn-in inspection

  • Since temperature & humidity affect the service life of IC's exposing the units to elevated temperature & humidity may help speed the burn-in inspection

  • However, Company A is concerned that this 'accelerated' burn-in may not produce meaningful information

• Study objectives

  • Estimate the probability of IC's failing before 100 hours

  • Estimate the hazard function at 100 hours

  • Estimate the required burn-in time to remove the majority of the defective units

• Data set (Table 1.2) lfp1370

  • Lifetimes of $n = 4156$ integrated circuits (IC's)

  • IC's were exposed to $80^{o}C$ and $80\%$ relative humidity until failure

  • The test was stopped after 1370 hours (28 failures were observed, the rest were right censored)

Auburngrads/SMRD documentation built on Sept. 14, 2020, 2:21 a.m.