Importance of multi-temp testing in automotive qualification and zero defects program

For automotive qualification of Integrated circuits (ICs), multi-temp testing is required by AEC-Q100. In this paper, we demonstrate the importance and necessity of this multi-temp testing in automotive qualification and zero defects program.During the qualification of one of our new products, we found that all samples could pass electrical testing at room temperature after high temperature operating life test, but a few of them failed at hot temperature. One transistor in the circuit was found to have large leakage current. Only at hot temperature, this leakage current was increased (>50 μA) and the fail was detected during hot electrical testing. Root cause was identified and design error is corrected before the release of the product. No failures are observed anymore.