A Comprehensive Methodology for Stress Procedures Evaluation and Comparison for Burn-In of Automotive SoC

Environmental and electrical stress phases are commonly applied to automotive devices during manufacturing test. The combination of thermal and electrical stress is used to give rise to early life latent failures that can be naturally found in a population of devices by accelerating aging processes through Burn-In test phases. This paper provides a methodology to evaluate and compare the stress procedures to be run during Burn-In; the proposed method takes into account several factors such as circuit activity, chip surface temperature and current consumption required by the stress procedure, and also considers Burn-In flow and tester limitations. A specific metric called Stress Coverage is suggested summing up all the stress contributions. Experimental results are gathered on an automotive device, showing the comparison between scan-based and functional stress run by a massively parallelized test equipment; reported figures and tables quantify the differences between the two approaches in terms of stress.