Wafer probe test cost reduction of an RF/A device by automatic testset minimization — A case study

Abstract

This work presents a case study of wafer probe test cost reduction by multivariate parametric testset optimization for a production RF/A device. More than 1.5 million tested device samples across dozens lots and hundreds of parametric measurements are analyzed using a new automatic testset minimization system. Parametric test subsets are found that can be used to predict infrequent wafer probe failures. Multivariate test models are generated to justify removal of ineffective tests, screen failures with minimal test cost, and demonstrate that some frequently passing tests are safe drop candidates. The proposed method is evaluated using parametric test data from an RF/A IC currently in production, showing how to reduce test cost and uncover tradeoffs between test escapes and overkills during high volume wafer probe screening.