Diagnosis of Failing Scan Cells through Orthogonal Response Compaction

This paper presents a novel scheme to address the challenge of identifying failing scan cells from production test responses in the presence of scan compression. The scheme is based on a very simple test response compactor employing orthogonal- spatial and time- signatures. The advantage of this scheme as compared to previous work in this field is the simple and incremental nature of the compaction hardware required. The ability of the scheme to accurately identify failing scan cells from compacted responses has been measured on production fail data from five industrial designs and is reported herein.