Evaluation of Microcircuit Accelerated Test Techniques PDF Download

Author: G. M. Johnson
Publisher:
ISBN:
Category :
Languages : en
Pages : 318

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Book Description
The results of an extensive life test matrix demonstrated the general validity and effectiveness of accelerated tests of microcircuits using both temperature and voltage as accelerating stresses. Over 2500 microcircuits from TTL, CMOS and linear technologies were life tested at ambient temperatures between 125C and 285C. In general, bimodal failure distributions, comprised of early (Freak) and late (main) lognormal distributions, were observed. The relationship of median life with junction temperature could be represented with an Arrehenius reaction rate model. Activation energies for the freak distribution ranged from 0.7 eV to 1.3 eV, and in certain instances a short high temperature burn-in to eliminate the freak population results in a dramatic improvement in use-temperature failure rates. Complete high temperature microcircuit life characterization and lot acceptance tests are required to identify economically screenable lots. MIL-STD-883 test methods are proposed for general application of microcircuit high temperature accelerated tests as a new tool for assuring the reliability of semiconductor production lots, and for screening out potential surface related failures. Included in the proposed methods are guidelines for assuring test effectiveness. The inherent effectiveness of accelerated tests can only be assured through careful selection of the life-test circuit configuration, and test temperatures, and the effective analysis of the resulting failure data.