IC Solder Joint Inspection via Robust Principle Component Analysis.

Defect inspection of integrated circuits (ICs) solder joints is a long-standing task. This paper proposes a novel IC solder joint inspection method based on the idea of robust principle component analysis (RPCA), which is a celebrated optimization technique. To the best of our knowledge, this is the first time IC solder joint inspection is formulated as an optimization problem. In particular, we model an IC solder joint image as observed data corrupted by gross errors. According to the RPCA theory, the observed data can be approximately decomposed into a low-rank component and an error component. In this paper, an appearance model of qualified IC solder joints is defined for IC solder joint inspection based on RPCA. Then, a defect score is defined based on the appearance model and is used to evaluate the quality of IC solder joints. Meanwhile, location prior knowledge related to human perception is incorporated in the defect score to further evaluate the defects of IC solder joints. Finally, a simple discrimination scheme is proposed to inspect IC solder joints. Experimental results indicate that the proposed method is superior to the existing methods in inspection performance. [ABSTRACT FROM AUTHOR]