JP2008256587A - X-ray inspection device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inspect the shape of a metal surface or the like at high spatial resolution in an X-ray inspection device. <P>SOLUTION: The X-ray inspection device irradiates an X-ray irradiation section 30 of an analyte 1 with X-rays 6 and inspects the surface shape of the analyte 1. The X-ray inspection device has an X-ray source 2 for irradiating the X-ray irradiation section 30 with the original X-rays 6, a plurality of X-ray detectors 4 that are arranged at an interval in a state facing the X-ray irradiation section 30 so as to detect a secondary X-rays (scattered X-rays 7 or fluorescent X-rays) released from each part of the X-ray irradiation section 30 according to the irradiation of the original X-rays 6 and detect two-dimensional X-ray intensity distribution, and a plurality of suppressing means (for example, collimator 3) that are arranged between the X-ray irradiation section 30 and X-ray detectors 4 and suppress depth angle of the secondary X-rays 7 reaching respective X-ray detectors 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an X-ray inspection apparatus and an X-ray inspection method suitable for surface inspection of a subject such as metal.

As a general X-ray inspection apparatus, it is known to perform an inspection based on a transmission image of the inside and surface of a subject by X-rays transmitted through the subject. Such an X-ray inspection apparatus includes an X-ray source that generates X-rays and an X-ray two-dimensional detector such as an X-ray film, an X-ray image intensifier, or an X-ray CCD camera. Some obtain a transmission image of a specimen. Further, as a special X-ray inspection apparatus, X-rays (original X-rays) from an X-ray source are irradiated on the subject surface, and secondary X-rays (fluorescent X-rays or scattered X-rays) emitted from the X-ray source are secondly emitted. There are known ones that detect a dimension and perform element distribution analysis on the surface of an object (see, for example, Patent Document 1 and Patent Document 2).
JP 2000-55842 A JP 2003-329622 A

  In the X-ray inspection apparatus described above, for example, when inspecting a scratch of about 10 μm on the surface of a metal plate having a thickness of about several tens of centimeters, the X-ray transmission inspection has a high energy and the number of photons is 10 μm or less. An X-ray source generated from the X-ray focal point is required. In such a case, electrons having a high power density are absorbed by the metal target that generates X-rays in the X-ray source, so that there is a problem in durability due to thermal shock of the metal target, which is difficult to realize. Therefore, it has been a problem that the number of X-ray photons necessary for inspection and the spatial resolution cannot be compatible.

  Further, in an inspection apparatus using fluorescent X-rays or scattered X-rays, the distance between the X-ray source and the subject cannot be shortened to a certain distance or less due to limitations on the shape and size of the X-ray source. Therefore, the number of irradiation X-ray photons on the subject surface is limited, and the number of fluorescent and scattered X-ray photons is also limited accordingly. For this reason, it is necessary to increase the collimator diameter in order to secure the number of X-ray photons necessary for detection, and it is difficult to ensure the spatial resolution determined by the collimator diameter.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an X-ray inspection apparatus and an X-ray inspection method capable of inspecting a shape such as a metal surface with high spatial resolution.

  The present invention achieves the above object, and one aspect of the present invention is an X-ray inspection apparatus that inspects the surface shape of a subject by irradiating the X-ray irradiation part of the subject with an original X-ray. The X-ray source for irradiating the X-ray irradiation unit with the original X-ray, and the secondary X-ray emitted from each part of the X-ray irradiation unit in response to the irradiation with the original X-ray, A plurality of X-ray detectors that are arranged opposite to each other and are spaced apart from each other and detect a two-dimensional X-ray intensity distribution, and are arranged between the X-ray irradiation unit and the X-ray detector. And a plurality of suppression means for suppressing a prospective angle of the secondary X-ray that reaches each of the X-ray detectors.

  Another aspect of the present invention is an X-ray that irradiates an original X-ray in an X-ray inspection apparatus that inspects the surface shape of the subject by irradiating the X-ray irradiation unit of the subject with the original X-ray. A source, an X-ray condensing optical element for condensing the original X-rays on the X-ray irradiation unit, and secondary X-rays emitted from the X-ray irradiation unit in response to the irradiation of the original X-rays As described above, the X-ray detector disposed facing the X-ray irradiation unit, the X-ray source, the X-ray focusing optical element, and the X-ray detector are relatively disposed with respect to the subject, and And a moving mechanism for moving along the subject.

  Furthermore, another aspect of the present invention is an X-ray inspection method for inspecting the surface shape of a subject by irradiating the X-ray irradiation portion of the subject with X-rays, facing the X-ray irradiation portion. An X-ray source for irradiating the original X-ray is disposed, and a plurality of X-ray detectors are disposed opposite to each other so as to face the X-ray irradiation unit, and between the X-ray irradiation unit and the X-ray detector. In addition, a plurality of suppression means for suppressing a prospective angle at which the X-ray irradiation unit is expected from each of the plurality of X-ray detectors is disposed, and emitted from each part of the X-ray irradiation unit according to the irradiation of the original X-ray The secondary X-ray to be detected is two-dimensionally detected by the plurality of X-ray detectors.

  Furthermore, another aspect of the present invention is an X-ray inspection method for inspecting the surface shape of a subject by irradiating the X-ray irradiation portion of the subject with X-rays, facing the X-ray irradiation portion. An X-ray source for irradiating the original X-ray, an X-ray condensing optical element for condensing the original X-ray on the X-ray irradiator, and an X-ray detector facing the X-ray irradiator The secondary X-ray emitted from the X-ray irradiation unit in response to the irradiation of the original X-ray is detected by the X-ray detector, and the X-ray source, the X-ray condensing optical element, and the X-ray are detected. The detector is moved relative to the subject and along the subject, and the detection of secondary X-rays by the X-ray detector is repeated.

  According to the present invention, it is possible to provide an X-ray inspection apparatus and an X-ray inspection method capable of inspecting a shape such as a metal surface with high spatial resolution.

  Hereinafter, embodiments of an X-ray inspection apparatus according to the present invention will be described with reference to the drawings.

[First Embodiment]
First, a first embodiment of the X-ray inspection apparatus according to the present invention will be described with reference to FIG. A plurality of (two in FIG. 1) X-ray sources 2 are arranged near the subject 1 so that X-rays (original X-rays) 6 are irradiated on the X-ray irradiation unit 30 of the subject 1 from each. Has been placed. A collimator 3 having a plurality of fine tubes 8 is arranged facing the X-ray irradiation unit 30 of the subject 1, and an X-ray two-dimensional detector 4 is arranged at each position where the X-ray irradiation unit 30 is viewed through the fine tubes 8. ing. The outside of the X-ray source 2 and the X-ray two-dimensional detector 4 is covered with a shield 5.

  In the present embodiment configured as described above, first, X-rays 6 from a plurality of X-ray sources 2 are irradiated two-dimensionally to the X-ray irradiation unit 30 of the subject 1. A part of the X-rays 6 irradiated to the X-ray irradiation unit 30 of the subject 1 is scattered on the surface or inside of the subject 1, and scattered X-rays 7 are emitted. A part of the scattered X-rays 7 emitted from the subject 1 passes through the collimator 3 in which a plurality of fine tubes 8 are opened, and then enters the X-ray two-dimensional detector 4 where the X-ray dose is two. Dimensionally detected.

  At this time, the positional relationship among the subject 1, the collimator 3 and the X-ray two-dimensional detector 4 is arranged as shown in FIG. 1, the collimator diameter, the collimator thickness, the distance between the subject 1 and the collimator 3, and the collimator 3 By setting the distance between the X-ray two-dimensional detector 4 to an appropriate value, the collimator 3 can expect the entire surface of the subject 1 uniformly and with a certain spatial resolution. In addition, since the number of photons of the scattered X-rays 7 changes depending on the surface shape (for example, unevenness) of the subject 1, information on the surface shape of the subject 1 is displayed two-dimensionally on the X-ray two-dimensional detector 4. It becomes.

  According to the present embodiment, since the surface shape information of the subject 1 is two-dimensionally displayed on the X-ray two-dimensional detector 4, the surface shape of the subject 1 can be inspected.

[Second Embodiment]
Next, a second embodiment of the X-ray inspection apparatus according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  The configuration of the present embodiment is almost the same as that in FIG. 1, but what is characteristic here is that the characteristic X-rays 10 unique to the target metal 9 of the plurality of X-ray sources 2 are used, and the surface of the subject 1 is released. The use of drooping fluorescent X-rays 11 and the use of an energy discrimination type X-ray two-dimensional detector 12.

  In the present embodiment configured as described above, first, characteristic X-rays 10 are irradiated two-dimensionally on the surface of the subject 1 from a plurality of X-ray sources 2. A part of the characteristic X-ray 10 irradiated to the subject 1 is absorbed by the surface of the subject 1, and the fluorescent X-ray 11 is emitted therefrom. A part of the fluorescent X-rays 11 emitted from the surface of the subject 1 passes through the collimator 3 in which a plurality of fine tubes 8 are opened, and then enters the X-ray two-dimensional detector 4 where the X-ray dose is Two-dimensionally detected. The subsequent operation is the same as that of the first embodiment, but the fluorescent X-ray 11 is more sensitive in intensity response to fine changes in the surface shape of the subject 1 than the scattered X-ray 7 in FIG. Is a feature. Thereby, it is possible to inspect the surface shape of the subject 1 with high resolution in the depth direction.

[Third Embodiment]
Next, a third embodiment of the X-ray inspection apparatus according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as 1st or 2nd embodiment, and the overlapping description is abbreviate | omitted.

  In the present embodiment, X-rays 6 generated from one (or some or all) of the plurality of X-ray sources 2 are incident on an X-ray focusing optical element 14 such as a Fresnel zone plate, and the X-rays 6 are emitted. It is configured to focus and irradiate the surface of the subject 1 with a minute point. A part of the X-ray 6 irradiated to the subject 1 is scattered on the surface or inside of the subject 1, and scattered X-rays 7 are emitted. A part of the scattered X-rays 7 emitted from the subject 1 is incident on the X-ray detector 13 where the X-ray dose is detected.

  In this embodiment, an X-ray inspection apparatus including an X-ray source 2, an X-ray detector 13, an X-ray condensing optical element 14, a shield 5 and the like is integrated, and the subject 1 is relatively relative to the subject 1. Is provided with a moving mechanism (not shown) for moving (scanning) along. By this moving mechanism, the position of the inspection apparatus is moved by about the condensed diameter of the X-ray 6, and the scattered X-ray dose is detected in the same manner each time. By performing this operation continuously and comparing the scattered X-ray dose in the range in which the inspection apparatus is moved (scanned), the shape change of the surface of the subject 1 can be detected. At this time, the condensing diameter of the X-ray 6 condensed by the X-ray condensing optical element 14 can be made smaller than the spatial resolution obtained by the X-ray inspection apparatus of the first embodiment. Therefore, a surface shape change with higher spatial resolution can be detected.

[Fourth Embodiment]
Next, a fourth embodiment of the X-ray inspection apparatus according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as 1st thru | or 3rd embodiment, and the overlapping description is abbreviate | omitted.

  In the present embodiment, an oscillator 15, a pulse power supply 16, and a time-resolved detector 17 (or a synchronous detector 18) are added to the configuration shown in FIG. In the present embodiment configured as described above, first, the pulse power source 16 is driven by the pulse signal from the oscillator 15 set to a certain repetition frequency, and the X-rays 6 from the plurality of X-ray sources 2 are pulsed. The subject 1 is irradiated. Thereafter, the operation up to the operation of detecting the scattered X-rays 7 emitted from the subject 1 by the X-ray two-dimensional detector 4 is the same as in the first embodiment.

  The X-ray dose detected by the X-ray two-dimensional detector 4 is two-dimensionally and time-resolved (pulse event measurement) by the time-resolved detector 17. Alternatively, only the pulse component is synchronously detected by the synchronous detector 18 synchronized with the oscillator 15. Further, since the X-ray 6 is generated in a pulse shape, the current peak value of the X-ray source 2 can be set higher than that at the time of direct current. Therefore, since the pulse peak value of the irradiated X-ray is higher than that at the time of direct current, the pulse peak value of the scattered X-ray 7 is similarly high.

  According to the present embodiment, since scattered event X-rays 7 having a high pulse peak value can be measured, for example, inspection with a high SN ratio (signal / noise ratio) in a radiation environment or the like can be performed. . In addition, since only scattered X-rays synchronized with the repetition frequency of X-rays 6 can be detected, an inspection with a high SN ratio can be performed in a noise environment (for example, in a radiation environment) having other frequency components.

[Fifth Embodiment]
Next, a fifth embodiment will be described with reference to FIG. In the present embodiment, in the configuration of the first embodiment (FIG. 1), instead of the collimator 3 installed on the front surface of the X-ray two-dimensional detector 4, an X-ray imaging optical element 19 is installed, The surface image of the specimen 1 is formed on the X-ray two-dimensional detector 4. The collimator 3 obtains an image of the subject surface based on the principle of a pinhole camera. In the fifth embodiment, the X-ray signal from the subject 1 can be detected efficiently and two-dimensionally detected. Therefore, it is possible to secure the spatial resolution and the number of X-ray photons as signals.

  Further, by adjusting the distances between the subject 1, the X-ray imaging optical element 19, and the X-ray two-dimensional detector 4, the enlargement ratio of the X-ray image of the subject 1 can be changed. It is possible to arbitrarily select a case in which a wide area is inspected roughly or a case in which a narrow area is inspected with high resolution by magnified imaging.

[Sixth Embodiment]
Next, a sixth embodiment of the X-ray inspection apparatus according to the present invention will be described with reference to FIG.

  The present embodiment is composed of an X-ray irradiation / detection device 20 and a surface unevenness monitor 21 formed integrally therewith. The X-ray irradiation / detection device 20 is, for example, the X-ray detection device according to any one of the first to fifth embodiments described above. The surface unevenness monitor 21 is a displacement sensor having, for example, a light projecting unit 23 that projects laser light 22 for measuring the distance between the surface and the sensor, and a light receiving unit 24 that receives reflected light from the surface. The surface unevenness state obtained from the surface unevenness monitor 21 is used for correction of scattering and fluorescent X-ray dose obtained by the X-ray irradiation / detection device 20 by data processing.

  In the present embodiment configured as described above, the surface unevenness monitor 21 measures the distance between the subject 1 and the X-ray irradiation / detection device 20, thereby correcting the error in the detected X-ray dose due to the distance. It becomes possible. Thereby, the measurement of a more accurate surface state is attained.

[Seventh Embodiment]
Next, a seventh embodiment of the X-ray inspection apparatus according to the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same or similar structure as 6th Embodiment, and the overlapping description is abbreviate | omitted.

  The present embodiment includes an X-ray irradiation / detection device 20 and a two-dimensional scanning surface unevenness monitor 25. The two-dimensional scanning surface unevenness monitor 25 has a mechanism for scanning the displacement sensor two-dimensionally. A two-dimensional scanning surface unevenness monitor 25 is installed in the traveling direction of the X-ray irradiation / detection device 20, and the surface state of the subject 1 is measured in advance, so that X-ray irradiation is performed by data processing according to the distance. -The scattering and fluorescent X-ray dose obtained by the detection device 20 can be corrected in real time, and more accurate real-time measurement of the surface state becomes possible.

[Eighth Embodiment]
Next, an eighth embodiment of the X-ray inspection apparatus according to the present invention will be described. This embodiment is a modification of the second embodiment (FIG. 2) and is similar to the second embodiment, but some or all of the targets of the plurality of X-ray sources 2 are made of different metal materials. There is a feature. In the present embodiment configured as described above, a plurality of types of characteristic X-rays 10 unique to different target metals can be obtained, and the subject 1 can be irradiated with these. The energy of the fluorescent X-ray is determined by the material of the subject 1. Therefore, by selecting the characteristic X-ray 10 suitable for the material (fluorescent X-ray 11) of the subject 1 and irradiating the subject 1, the surface shape inspection of the subject 1 made of a plurality of materials can be performed.

1 is a longitudinal sectional view of a first embodiment of an X-ray inspection apparatus according to the present invention. It is a longitudinal cross-sectional view of 2nd Embodiment of the X-ray inspection apparatus which concerns on this invention. It is a longitudinal cross-sectional view of 3rd Embodiment of the X-ray inspection apparatus which concerns on this invention. It is a longitudinal cross-sectional view of 4th Embodiment of the X-ray inspection apparatus which concerns on this invention. It is a longitudinal cross-sectional view of 5th Embodiment of the X-ray inspection apparatus which concerns on this invention. It is a figure which shows 6th Embodiment of the X-ray inspection apparatus which concerns on this invention, Comprising: (a) is a whole perspective view, (b) is the perspective view which looked at the light projection part and light-receiving part of (a) from the bottom. It is. It is a figure which shows 7th Embodiment of the X-ray inspection apparatus which concerns on this invention, Comprising: (a) is a whole perspective view, (b) is the perspective view which looked at the light projection part and light-receiving part of (a) from the downward direction. It is.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Subject, 2 ... X-ray source, 3 ... Collimator, 4 ... X-ray two-dimensional detector, 5 ... Shielding body, 6 ... X-ray, 7 ... Scattered X-ray, 8 ... Micro tube, 9 ... Target metal, DESCRIPTION OF SYMBOLS 10 ... Characteristic X-ray, 11 ... Fluorescence X-ray, 12 ... Energy discrimination type X-ray two-dimensional detector, 13 ... X-ray detector, 14 ... X-ray condensing optical element, 15 ... Oscillator, 16 ... Pulse power supply, 17 ... time-resolved detector, 18 ... synchronous detector, 19 ... X-ray imaging optical element, 20 ... X-ray irradiation / detection device, 21 ... surface unevenness monitor, 22 ... laser light, 23 ... light projecting unit, 24 ... light reception 25: Two-dimensional scanning surface unevenness monitor, 30 ... X-ray irradiation unit

Claims (13)

In an X-ray inspection apparatus that inspects the surface shape of a subject by irradiating the X-ray irradiation part of the subject with original X-rays,
An X-ray source for irradiating the X-ray irradiator with original X-rays;
Two-dimensionally arranged opposite to the X-ray irradiation unit so as to detect secondary X-rays emitted from each part of the X-ray irradiation unit in response to the irradiation of the original X-ray. A plurality of X-ray detectors for detecting a dynamic X-ray intensity distribution;
A plurality of suppression means arranged between the X-ray irradiator and the X-ray detector, for suppressing a prospective angle of the secondary X-ray reaching each X-ray detector;
An X-ray inspection apparatus characterized by comprising:   The X-ray inspection apparatus according to claim 1, wherein the suppression unit is a collimator.   The X-ray inspection apparatus according to claim 1, wherein the suppression unit is an X-ray imaging optical element. In an X-ray inspection apparatus that inspects the surface shape of a subject by irradiating the X-ray irradiation part of the subject with original X-rays,
An X-ray source that irradiates the original X-ray;
An X-ray focusing optical element that focuses the original X-rays on the X-ray irradiation unit;
An X-ray detector disposed opposite to the X-ray irradiation unit so as to detect secondary X-rays emitted from the X-ray irradiation unit in response to irradiation of the original X-ray;
A moving mechanism for moving the X-ray source, the X-ray focusing optical element and the X-ray detector relative to the subject and along the subject;
An X-ray inspection apparatus characterized by comprising:   The X-ray inspection apparatus according to any one of claims 1 to 4, wherein the secondary X-ray is a scattered X-ray.   The X-ray inspection apparatus according to any one of claims 1 to 4, wherein the secondary X-ray is a fluorescent X-ray.   The X-ray source is a pulse X-ray source, and the X-ray detector performs pulse event measurement or synchronous detection. X-ray inspection equipment.   The X-ray inspection apparatus according to claim 1, further comprising a subject surface unevenness monitor that inspects the surface unevenness of the subject.   9. The X-ray inspection apparatus according to claim 1, wherein there are a plurality of X-ray sources, and the plurality of X-ray sources can simultaneously irradiate an original X-ray. .   The X-ray inspection apparatus according to claim 1, wherein there are a plurality of X-ray sources, and the plurality of X-ray sources can irradiate different characteristic X-rays. . In an X-ray inspection method for inspecting the surface shape of a subject by irradiating the X-ray irradiation part of the subject with X-rays,
An X-ray source that irradiates the original X-rays facing the X-ray irradiation unit
A plurality of X-ray detectors are arranged at intervals from each other so as to face the X-ray irradiation unit,
Between the X-ray irradiator and the X-ray detector, a plurality of suppression means for suppressing a prospective angle to expect the X-ray irradiator from each of the plurality of X-ray detectors,
Two-dimensionally detecting secondary X-rays emitted from each part of the X-ray irradiation unit in response to the irradiation of the original X-rays by the plurality of X-ray detectors;
X-ray inspection method characterized by the above. In an X-ray inspection method for inspecting the surface shape of a subject by irradiating the X-ray irradiation part of the subject with X-rays,
An X-ray source that irradiates the original X-rays facing the X-ray irradiation unit is disposed,
An X-ray condensing optical element that condenses the original X-ray on the X-ray irradiation unit is disposed,
An X-ray detector is disposed opposite the X-ray irradiation unit,
Secondary X-rays emitted from the X-ray irradiation unit in response to irradiation of the original X-rays are detected by the X-ray detector;
The X-ray source, the X-ray condensing optical element, and the X-ray detector are moved relative to the subject and along the subject, so that secondary X-rays generated by the X-ray detector are generated. Repeating detection,
X-ray inspection method characterized by the above.   13. The method according to claim 11, further comprising: detecting irregularities on the surface of the X-ray irradiation unit by a surface irregularity monitor attached to the X-ray source, the X-ray focusing optical element, and the X-ray detector. The X-ray inspection method described.

Images