X-ray inspection device and X-ray inspection method
View Patent ↗In order to prevent misdetection and erroneous detection by clearly determining only a contrast caused by a foreign matter, there are provided an X-ray inspection method and an X-ray inspection device including: an X-ray tube ( 11 ) for irradiating a measurement sample with a characteristic X-ray having energy lower than an X-ray absorption edge of one element contained in the measurement sample and having energy higher than an X-ray absorption edge of a detection element; an X-ray detector ( 13 ) for receiving a transmission X-ray obtained when the X-ray passes through the sample; and an operation portion ( 15 ) for obtaining a contrast image from a transmission image of the transmission X-ray.
1. A method for detecting whether Fe is present as foreign matter in a manufactured sample containing lithium cobalt oxide, comprising the steps:
irradiating the manufactured sample containing lithium cobalt oxide with characteristic x-rays generated by an x-ray tube having Ni target tube, the characteristic x-rays having energy lower than an x-ray absorption edge of a constituent element of the sample and having energy higher than an x-ray absorption edge of Fe so that Fe present in the sample absorbs the characteristic x-rays to a greater degree than the constituent element of the sample;
detecting the intensity of the characteristic x-rays that pass through the sample; and
creating an image which shows a distribution of the detected intensity of the characteristic x-rays passing through the sample and in which Fe present in the sample appears in clear contrast.
2. A method according to claim 1 ; wherein the irradiating step includes, before irradiating the sample with characteristic x-rays, passing the characteristic x-rays through a Co foil filter having an x-ray absorption edge of energy higher than that of the characteristic x-rays.
3. A method according to claim 1 ; wherein the manufactured sample is an electrode of a secondary battery.
4. A method according to claim 1 ; wherein the manufactured sample is an electrode of a lithium-ion secondary battery.
5. A method for detecting whether Cr is present as foreign matter in a manufactured sample containing lithium manganese oxide, comprising the steps:
irradiating the manufactured sample containing lithium manganese oxide with characteristic x-rays generated by an x-ray tube having an Fe target tube, the characteristic x-rays having energy lower than an x-ray absorption edge of a constituent element of the sample and having energy higher than an x-ray absorption edge of Cr so that Cr present in the sample absorbs the characteristic x-rays to a greater degree than the constituent element of the sample;
detecting the intensity of the characteristic x-rays that pass through the sample; and
creating an image which shows a distribution of the detected intensity of the characteristic x-rays passing through the sample and in which Cr present in the sample appears in clear contrast.
6. A method according to claim 5 ; wherein the irradiating step includes, before irradiating the sample with characteristic x-rays, passing the characteristic x-rays through a Mn foil filter having an x-ray absorption edge of energy higher than that of the characteristic x-rays.
7. A method according to claim 5 ; wherein the manufactured sample is an electrode of a secondary battery.
8. A method according to claim 5 ; wherein the manufactured sample is an electrode of a lithium-ion secondary battery.