X-ray inspection apparatus and x-ray inspection method

Abstract

Provided are an X-ray inspection apparatus and an X-ray inspection method capable of continuously inspecting even a long sheet-shaped sample while performing intensity correction. The X-ray inspection apparatus includes an X-ray source; a sample moving mechanism; an X-ray detector equipped with a line sensor with pixels detecting X-ray radiation passing through a sample; an image storage unit for storing X-ray radiation intensities; an intensity correction unit for correcting the X-ray radiation intensities stored in the image storage unit; and a defect detector for detecting a defect in the sample. The intensity correction unit sets an intensity of X-rays detected from the inspection initiation region after starting inspection of the sample or an intensity of X-rays preliminarily detected from the sample before starting the inspection as a reference radiation intensity, and corrects an intensity of X-rays detected from the subsequent inspection region based on a correction coefficient obtained from comparison between the intensity of X-rays detected from the subsequent inspection region and the reference radiation intensity.

Description

technical field [0001] The present invention relates to an X-ray inspection device and an X-ray inspection method capable of detecting foreign matter and the like in a sample. Background technique [0002] Generally, X-ray transmission inspection is used in order to detect tiny foreign matter such as metal in a sheet-like long sample (inspection object). The sample is transported between the radiation detectors, and the presence or absence of foreign matter is determined from the X-ray transmission image obtained by irradiating the sample with X-rays. [0003] In an X-ray inspection apparatus used in such an X-ray transmission inspection, since inspection operations are continuously performed, temporal stability is required in terms of the inspection capability of the apparatus. However, in general, the X-ray intensity of the X-ray source and the sensitivity of the X-ray detector fluctuate with time. In addition, elements of the X-ray detector degrade in detection intensit...

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Problems solved by technology

Therefore, there is a problem that immediately after the data correction process, all the components have the same output, and the output shifts over time, the overall value decreases, or the output deviation between components occurs, resulting in a decrease in the detection capability of the inspection device.

That is, in the case of inspecting a sheet-shaped sample by the roll-to-roll method, etc., when a correction operation is performed during the inspection at a set period, the inspection can only be performed stably at the interval until the intensity correction, so it is difficult to Continuously perform X-ray foreign matter inspection of strips of several kilometers to tens of kilometers

In addition, intensity correction must be performed without a sample, and in the case of a sheet-like sample, there is always a sample between the X-ray source and the X-ray detector, so it is difficult to perform correction

[0012] In the above-mentioned prior patent documents 1 and 2, although a method of performing intensity correction in an area without a sample and a method of performing intensity correction using a signal of a boundary portion (a portion not required to be inspected) are described, they cannot be sufficiently corrected. When the section without the sample and the boundary part (short) are obtained accurately, there may be cases where the correction cannot be performed correctly

In particular, in the case of the above-mentioned elongated sheet-like sample, since the sample is supplied continuously without interruption, it is difficult to apply the techniques of Patent Documents 1 and 2.

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