A review of plastic-encapsulated-microcircuitreliability-prediction models

摘要

This paper reviews available plastic encapsulated microcircuit(PEM) reliability prediction models including the CNET, Thomson-CSF andRAC model. We examine the RAC (Reliability Analysis Center) model indetail, as it is the only usable model that considers the acceleratingeffects of temperature and humidity on PEM failures. Our intention is toprovide constructive criticisms and propose amendments. We agreed withthe assumptions made by the RAC model: types of packaging do not affectPEM failure rate; and a single activation energy of 0.8 eV may beadequate for different IC logic families. However, we feel that the RACmodel should incorporate a term for EOS/ESD failures as they constitutesa high percentage (up to 43%) of IC failures. The RAC model should setan upper limit of 130° C and 99% RH when using Peck's model to modeltemperature/humidity acceleration so as to avoid violatingphysics-of-failure considerations. It should consider treatingmicroprocessor and memories as two different classes of devices due tothe vast differences in their reliability as indicated by someliteratures. We question if the reliability growth rate can be projectedwithout restrictions. There should also be clearer indications of whatconstitutes “best commercial practices”-a prerequisite toapply the model