An Automated Detection Method of Solder Joint Defects Using 3D Computed Tomography for IC Package Inspection

Recent electronics parts continue to decrease in size so that it is more likely to exhibit defects. Lately, computed tomography scanning technique has been introduced to provide useful tools for the internal inspection of electronic packages. In this paper, we presents a novel method for detecting solder joint defects in the 3D packaging devices. Our method is composed of three steps. First, mis-alignment during the CT scan process is corrected. Second, open solder joints, missing solder joints, and solder bridges are detected using blob labeling procedure. Finally, head-in-pillow defect is inspected by the principal curvature analysis. The experimental results demonstrated that our method accurately detected solder joint defects within less than one second. Our method can be successfully applied to inline manufacturing, which requires rapid inspection of whole chips.