X-ray transmission inspection apparatus and X-ray transmission inspection method
Proposed are an X-ray transmission inspection apparatus and an X-ray transmission inspection method, in which transmission images with a large difference between irradiation angles are obtained so that the depth of the position of a foreign object can be obtained with high precision. The apparatus includes an X-ray source, an X-ray sensor configured to detect a transmitted X-ray, a sample moving mechanism configured to move the sample in a specific transport direction, and a calculation part configured to calculate a height position of a foreign object in a thickness direction in the sample on the basis of the transmitted X-ray detected by the X-ray sensor, wherein the X-ray source and the X-ray sensor include X-ray sources and X-ray sensors, the X-ray sources irradiate the sample with x-rays, and the X-ray sensors are disposed to respectively detect only transmitted X-rays of X-rays from the corresponding X-ray sources.
1 . An X-ray transmission inspection apparatus comprising:
a plurality of X-ray sources, each X-ray source of the plurality of X-ray sources configured to irradiate a sample with X-rays;
a plurality of X-ray sensors, each X-ray sensor of the plurality of X-ray sensors installed on a side opposite to the X-ray source relative to the sample and configured to detect transmitted X-rays when X-rays pass through the sample;
a sample moving mechanism configured to move the sample in a transport direction; and
a calculation part configured to calculate a height position of a foreign object in a thickness direction in the sample based on the transmitted X-rays detected by the X-ray sensor,
wherein a plurality of sets of the plurality of X-ray sources paired with the plurality of X-ray sensors in one-to-one correspondence are provided,
each X-ray source of the plurality of sets of the plurality of X-ray sources paired with the plurality of X-ray sensors in one-to-one correspondence irradiates the sample with X-rays at a different irradiation angle with respect to the thickness direction of the sample, and
a position in the transport direction at which the foreign object in the sample is first detected by the X-ray sensor of one of the plurality of sets is set as a first passing point; a position in the transport direction at which the foreign object in the sample is detected based on transmitted X-rays detected by the X-ray sensor of the other one of the plurality of sets after the first passing point is detected is set as a second passing point; and the calculation part calculates the height position of the foreign object based on a distance between the first passing point and the second passing point, and the irradiation angles of the sets that detected the foreign object.
2 . The X-ray transmission inspection apparatus according to claim 1 , wherein an imaging start position of the sample in a predetermined transport direction is set as a reference point; and a distance between the first passing point and the second passing point is calculated based on the reference point.
3 . The X-ray transmission inspection apparatus according to claim 1 , wherein the X-ray sensor is a TDI sensor.
4 . The X-ray transmission inspection apparatus according to claim 2 , wherein the X-ray sensor is a TDI sensor.
5 . The X-ray transmission inspection apparatus according to claim 1 , further comprising:
a reference piece installed on a surface of the sample,
wherein the calculation part calculates the height position of the foreign object by comparison with a height position of the reference piece.
6 . The X-ray transmission inspection apparatus according to claim 1 , wherein each X-ray source of the plurality of sets of the plurality of X-ray sources paired with the plurality of X-ray sensors in one-to-one correspondence perform irradiation with X-rays in directions in which X-rays intersect one another.
7 . The X-ray transmission inspection apparatus according to claim 2 , wherein each X-ray source of the plurality of sets of the plurality of X-ray sources paired with the plurality of X-ray sensors in one-to-one correspondence perform irradiation with X-rays in directions in which X-rays intersect one another.
8 . The X-ray transmission inspection apparatus according to claim 1 , wherein each X-ray source of the plurality of sets of the plurality of X-ray sources paired with the plurality of X-ray sensors in one-to-one correspondence irradiates regions spaced apart from one another in the transport direction with X-rays.
9 . The X-ray transmission inspection apparatus according to claim 2 , wherein each X-ray source of the plurality of sets of the plurality of X-ray sources paired with the plurality of X-ray sensors in one-to-one correspondence irradiates regions spaced apart from one another in the transport direction with X-rays.
10 . An X-ray transmission inspection method using the X-ray transmission inspection apparatus according to claim 1 , the X-ray transmission inspection apparatus comprising two sets of the plurality of X-ray sources paired with the plurality of X-ray sensors in one-to-one correspondence, the method comprising:
moving the sample in the transport direction;
detecting, as the first passing point, the position in the transport direction at which the foreign object in the sample is detected based on transmitted X-rays detected by the X-ray sensor of one of two sets of the plurality of X-ray sources paired with the plurality of X-ray sensors in one-to-one correspondence;
detecting, as the second passing point, the position in the transport direction at which the foreign object in the sample is detected based on transmitted X-rays detected by the X-ray sensor of the other one of two sets of the plurality of X-ray sources paired with the plurality of X-ray sensors in one-to-one correspondence; and
calculating the height position of the foreign object in the sample based on the first passing point, the second passing point, and the irradiation angles of the plurality of X-ray sources of the two sets of the plurality of X-ray sources paired with the plurality of X-ray sensors in one-to-one correspondence.