X-ray inspection is a technology based on the same principles as automated optical inspection (AOI). It uses X-rays as its source, instead of visible light, to automatically inspect features, which are typically hidden from view.

An x-ray inspection produces images of the object. The image is then processed by image processing software that detects the position and size/ shape of expected features (for process optimization) or presence/ absence of unexpected/ unintended objects or features (for anomaly detection). Instead of (visible) light it uses x-rays (typically generated by an x-ray tube) that pass through the object. Opposite the x-ray emitter is a detector that either converts x-ray into visible light (creating an optical image which is then picked up by a camera) or sensor arrays that directly pick up the x-ray and convert it into an electronic image. The image is produced due to the different absorption of x-rays when passing through the object and can therefore reveal structures inside the object that are hidden from outside view.

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