Development of high-speed X-ray CT inspection system using X-ray line sensor

The recent progress in surface mount technology has highlighted an urgent demand for a higher performance level of inspection technology. X-ray inspection is one of the most suitable systems for substituting the conventional automated optical inspection system. In particular, X-ray computed tomography (CT) inspection provides precise inspection as it can obtain three-dimensional data and can distinguish the features on the top side of a double-sided printed circuit board (PCB) from those on the bottom side. However, X-ray inspection systems are not in common use in the surface mount production line due to their complex image capturing mechanism, which requires a longer inspection time. Taking this limitation into consideration, we developed a simple mechanism utilizing an X-ray line sensor to obtain CT images of a wide area at a faster rate. We term this system as linear CT. In this paper, we explain the image capturing mechanism of linear CT and report that this mechanism can generate cross-sectional images of sufficiently high quality for precise inspection.