Radiation analysis device, radiation analysis method and radiation analysis system

Abstract

To reduce an impact of secondary radiation generating from a layer not targeted for analysis in a radiation analysis device analyzing a workpiece having a plurality layers generating the secondary radiation.SOLUTION: A radiation analysis device analyzes a workpiece equipped with a plurality of layers apart from one another in which primary radiation is emitted to generate secondary radiation, and comprises: a radiation source that emits the primary radiation expanding at a prescribed angle toward a surface of the workpiece from a crossing direction relative to the plurality of layers; and a radiation detector that faces the surface of the workpiece, and detects the secondary radiation generating from the workpiece. The radiation source and the radiation detector are arranged so that, when viewing from the radiation source and the radiation detector, the secondary radiation generating in a prescribed analysis object layer of the plurality of layers is incident upon the radiation detector, and the secondary radiation generating in at least one non-analysis object layer located on a further depth side than the analysis object layer is not incident upon the radiation detector.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a radiation analysis device, a radiation analysis method, and a radiation analysis system. [Background technology]

[0002] Conventionally, for example, fluorescent X-ray analyzers have been used to measure the film thickness of a coating layer formed on the surface of a workpiece (for example, Patent Document 1). By using this fluorescent X-ray analyzer, the coating layer is irradiated with primary X-rays, and fluorescent X-rays (secondary X-rays) generated from the coating layer are detected by a detector, and quantitative analysis, qualitative analysis, or film thickness measurement of the coating layer can be performed based on the spectral distribution of the detected fluorescent X-rays. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-003306 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a workpiece has multiple coating layers that generate secondary radiation when irradiated with primary radiation, and the base material of the workpiece is made of a material that is transparent to radiation, when attempting to measure the thickness of a target coating layer using a radiation analysis device such as the above-mentioned X-ray fluorescence analysis device, a problem may arise in that the secondary radiation generated from the multiple coating layers is detected by the detector, making it impossible to accurately measure the thickness of the target coating layer.

[0005] The present invention has been made to solve all of the above-mentioned problems at once, and its main objective is to reduce the influence of secondary radiation generated from layers that are not the subject of analysis in a radiation analysis device that analyzes a workpiece having multiple layers that generate secondary radiation. [Means for solving the problem]

[0006] In other words, the radiation analysis apparatus of the present invention is for analyzing a workpiece having a plurality of spaced-apart layers that are irradiated with primary radiation and generate secondary radiation, and is equipped with a radiation source that irradiates primary radiation that spreads at a predetermined emission angle toward the surface of the workpiece from a direction intersecting the plurality of layers, and a radiation detector that faces the surface of the workpiece and detects secondary radiation generated from the workpiece, and is characterized in that, when viewed from the radiation source and the radiation detector, secondary radiation generated in a predetermined analysis target layer among the plurality of layers is incident on the radiation detector, and secondary radiation generated in at least one non-analysis target layer located behind the analysis target layer is not incident on the radiation detector.

[0007] With this configuration, it is possible to allow secondary radiation generated in a specific layer to be analyzed (e.g., the layer located at the front) among the multiple layers spaced apart from one another to be incident on the radiation detector, while preventing secondary radiation generated in at least one layer not to be analyzed located behind the layer to be analyzed from being incident on the radiation detector, thereby preventing detection of secondary radiation generated from layers not to be analyzed and reducing the adverse effects thereof. Note that, in this specification, "multiple layers are spaced apart from one another" means that the multiple layers are spaced apart from one another in the thickness direction.

[0008] As a means for analyzing only a specific layer to be analyzed among a plurality of layers, a so-called confocal X-ray fluorescence analysis method is considered, in which polycapillary X-ray lenses or the like are attached to both the radiation source and the radiation detector, and their focal points are aligned on the layer to be analyzed. However, in this confocal X-ray fluorescence analysis method, if the positional relationship between the layer to be analyzed and the radiation source and the radiation detector is shifted even slightly, for example, due to the workpiece being transported, the focal points of the radiation source and the radiation detector are shifted from the layer to be analyzed, and the layer to be analyzed cannot be analyzed. In contrast, according to the present invention, the layer to be analyzed is irradiated with primary radiation that spreads at a predetermined emission angle over a wide area, and the radiation source and the radiation detector are arranged so that only secondary radiation generated in a specific layer to be analyzed is incident on the radiation detector. Therefore, even if the positional relationship between the layer to be analyzed and the radiation source and the radiation detector is shifted slightly, for example, due to the workpiece being transported, the radiation detector can detect the secondary radiation from the layer to be analyzed, and the analysis can be performed.

[0009] Furthermore, it is preferable that, in the layer to be analyzed, the radiation analysis apparatus has an overlapping area between an irradiation area of ​​the primary radiation from the radiation source and a detection area in which the secondary radiation can be detected by the radiation detector, and that, in the layer not to be analyzed, the irradiation area and the detection area do not overlap. In this manner, secondary radiation is not generated from the detection region of the radiation detector in the layers not to be analyzed, so that secondary radiation generated from the layers not to be analyzed can be more reliably prevented from entering the radiation detector.

[0010] In addition, it is preferable that the radiation detector of the radiation analysis device includes a detection element that detects the secondary radiation, and a view angle limiting element that is arranged in front of the detection element and limits the view angle at which the secondary radiation can be detected by the detection element. In this way, by limiting the field of view angle that can be detected by the radiation detector, it becomes less likely that the irradiation area and the detection area in the layer not to be analyzed will overlap, thereby allowing for greater freedom in the positioning of the radiation source and the radiation detector.

[0011] In the radiation analysis apparatus, the radiation source preferably includes a radiation angle limiting element that limits the radiation angle of the primary radiation. In this way, by limiting the azimuth angle of the primary radiation, it becomes even less likely that the irradiation area and the detection area will overlap in the layer not to be analyzed, thereby allowing even greater freedom in the positioning of the radiation source and radiation detector.

[0012] In a specific embodiment of the radiation analysis device, the workpiece is transported along a predetermined transport direction.

[0013] A specific embodiment of the radiation analysis device in which the effects of the present invention become more pronounced is one in which the workpiece has a plurality of sheet-like sheet portions facing each other with a gap therebetween, the layer to be analyzed is formed on the surface of a front sheet portion that is located furthest from the front of the plurality of sheet portions when viewed from the radiation source and the radiation detector, and the layer not to be analyzed is formed on the surface of a rear sheet portion that is located further back than the front sheet portion from the plurality of sheet portions.

[0014] A specific embodiment of the radiation analysis device is one in which the radiation source emits X-rays as the primary radiation, the radiation detector detects fluorescent X-rays as the secondary radiation, and detects fluorescent X-rays generated from the layer to be analyzed to perform quantitative analysis of elements contained in the layer to be analyzed.

[0015] A specific embodiment of the radiation analysis device is one that analyzes the workpiece and measures the film thickness or deposition amount of the analysis target layer.

[0016] The radiation analysis method of the present invention is a method for analyzing a workpiece having a plurality of spaced-apart layers that are irradiated with primary radiation and generate secondary radiation, comprising the steps of: irradiating primary radiation spreading at a predetermined emission angle from a radiation source toward a surface of the workpiece from a direction intersecting the plurality of layers; detecting secondary radiation generated from the workpiece by a radiation detector facing the surface of the workpiece; and positioning the radiation source and the radiation detector such that, as viewed from the radiation source and the radiation detector, secondary radiation generated in a predetermined analysis target layer among the plurality of layers is allowed to enter the radiation detector, while secondary radiation generated in at least one non-analysis target layer located behind the analysis target layer is not allowed to enter the radiation detector. Such a radiation analysis method can achieve the same effects as those achieved by the above-described radiation analysis apparatus of the present invention.

[0017] A radiation analysis system according to the present invention includes the above-mentioned radiation analysis device, and a transport device that transports the workpiece along a predetermined transport direction. Such a radiation analysis system can achieve the same effects as the above-described radiation analysis system of the present invention. Effect of the Invention

[0018] According to the present invention described above, in a radiation analysis device that analyzes a workpiece having multiple layers that generate secondary radiation, it is possible to reduce the influence of secondary radiation generated from layers that are not the subject of analysis. [Brief description of the drawings]

[0019] [Figure 1] 1 is a diagram showing the overall configuration of a radiation analysis system according to an embodiment of the present invention; [Diagram 2] FIG. 13 is a diagram showing the overall configuration of a radiation analysis system according to another embodiment. [Diagram 3] FIG. 13 is a diagram showing the overall configuration of a radiation analysis system according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, a radiation analysis system 300 including a radiation analysis apparatus 100 according to an embodiment of the present invention will be described with reference to the drawings.

[0021] As shown in FIG. 1, the radiation analysis system 300 of this embodiment includes a conveying device 200 that conveys a workpiece W along a predetermined conveying direction, and a radiation analysis device 100 that analyzes the workpiece W by irradiating radiation (also called primary radiation) toward the conveyed workpiece W and detecting radiation (also called secondary radiation) generated from the workpiece W.

[0022] The workpiece W in this embodiment is sheet-shaped and includes a sheet-shaped base material a made of a material (e.g., resin, etc.) that does not easily generate primary radiation, and a coating layer b formed on one surface of the base material a and made of a material (e.g., metal, etc.) that generates secondary radiation when irradiated with primary radiation.

[0023] The conveying device 200 is, for example, a roll-to-roll type that conveys the workpiece W using a plurality of drum rolls 210, but is not limited thereto. In this embodiment, the workpiece W is conveyed in such a manner that it is folded back by the drum rolls 210, so that the first sheet portion w1 and the second sheet portion w2 that face each other with a gap therebetween are moved in opposite directions. In this conveying state, a total of two coating layers b1, b2 formed on the surfaces of the first sheet portion w1 and the second sheet portion w2 are formed parallel to each other and spaced apart in the thickness direction.

[0024] The radiation analysis apparatus 100 of this embodiment is an X-ray fluorescence analysis apparatus 100 that performs qualitative and quantitative analysis of elements contained in the workpiece W by irradiating the workpiece W with X-rays as primary radiation and detecting fluorescent X-rays generated from the workpiece W as secondary radiation. Specifically, as shown in FIG. 1, the radiation analysis apparatus 100 includes a radiation source 1 (specifically, an X-ray tube) that irradiates the workpiece W with primary radiation, a radiation detector 2 (specifically, an X-ray detector) that detects secondary radiation generated from the workpiece W, and an analysis unit 3 that analyzes the workpiece W based on an output from the radiation detector 2. In the radiation analysis apparatus 100 of this embodiment, the radiation source 1 and the radiation detector 2 are both arranged to face the surface of the first sheet portion w1 of the workpiece W.

[0025] The radiation source 1 irradiates the surface of the first sheet portion w1 with radial primary radiation from a direction intersecting the multiple coating layers b1 and b2. The radiation source 1 includes a radiation angle limiting element 11 that limits the radiation angle θ1 of the emitted primary radiation, and the emitted primary radiation is spread at a predetermined radiation angle θ1 by the radiation angle limiting element 11. The radiation source 1 of this embodiment is disposed so that the angle φ1 between the central axis 1a of the emitted primary radiation and the surface of the first sheet portion w1 is less than 90° (i.e., oblique to the surface of the first sheet portion w1). The primary radiation emitted from the radiation source 1 passes through the base material a of each of the first sheet portion w1 and the second sheet portion w2, and is irradiated to all of the two coating layers b1 and b2 formed on the surfaces of each of the first sheet portion w1 and the second sheet portion w2.

[0026] The radiation detector 2 detects secondary radiation generated from the workpiece W. Specifically, the radiation detector 2 is, for example, a silicon drift detector configured using a semiconductor detection element such as a Si element as a detection element, and outputs a current proportional to the energy of the detected secondary radiation.

[0027] The radiation detector 2 includes a detection element that detects secondary radiation, and a view angle limiting element 21 that is disposed in front of the detection element and limits a view angle θ2 at which the detection element can detect the secondary radiation. The view angle limiting element 21 has a view angle θ2 at which the secondary radiation can be detected set within a predetermined range, and can detect secondary radiation generated within the view. The view angle limiting element 21 is a ring-shaped element made of heavy elements that have low transmittance for radiation (specifically, X-rays), and is a so-called collimator. The radiation detector 2 is disposed so that the angle φ2 between the central axis 2a of its detection view field and the surface of the first sheet portion w1 is 90° (i.e., so as to be perpendicular to the surface of the first sheet portion w1).

[0028] In this embodiment, the radiation detector 2 and the radiation source 1 are oriented so that the central axis 2a of the detection field of view of the radiation detector 2 intersects with the central axis 1a of the primary radiation emitted from the radiation source 1 on the surface of the first sheet portion w1. The radiation source 1 and the radiation detector 2 are also arranged so that the in-plane direction of a plane including their respective central axes 1a, 2a is approximately parallel to the direction of movement of the transport device 200.

[0029] The analysis unit 3 receives the current output by the radiation detector 2 and acquires the spectrum of the secondary radiation. Based on the acquired spectrum, the analysis unit 3 performs qualitative and quantitative analysis of the elements that generated the secondary radiation, identifies the elements contained, analyzes foreign matter, and measures the thickness and deposition amount of the coating layer.

[0030] Thus, in the radiation analysis system 300 of this embodiment, the radiation source 1 and the radiation detector 2 are arranged such that, as viewed from the radiation source 1 and the radiation detector 2, secondary radiation generated in the coating layer b1 located at the forefront of the multiple coating layers b1, b2 is incident on the radiation detector 2, and secondary radiation generated in at least one coating layer located behind the coating layer b1 is not incident on the radiation detector 2. Specifically, the radiation source 1 and the radiation detector 2 are arranged such that secondary radiation generated in the coating layer b1 (referred to as the layer to be analyzed) formed on the surface (outward surface) of the first sheet portion w1 is incident on the radiation detector 2, and secondary radiation generated in the coating layer b2 (referred to as the layer not to be analyzed) formed on the surface (outward surface) of the second sheet portion w2 is not incident on the radiation detector 2.

[0031] More specifically, in the radiation analysis system 300, in the layer b1 to be analyzed, an area irradiated with primary radiation by the radiation source 1 and a detection area in which secondary radiation can be detected by the radiation detector 2 overlap, while in the layer b2 not to be analyzed, an area irradiated with primary radiation by the radiation source 1 and a detection area by the radiation detector 2 do not overlap. Note that the radiation source 1 and the radiation detector 2 are arranged such that the length of the irradiation area in the layer b1 to be analyzed is smaller than the length of the detection area when viewed from a direction perpendicular to the central axes 1a, 2a of the radiation source 1 and the radiation detector 2, respectively.

[0032] The arrangement of the radiation source 1 and the radiation detector 2 is set based on the distance X between the analysis target layer b1 and the non-analysis target layer b2. Specifically, the distance between the analysis target layer b1 and the non-analysis target layer b2 is X, the angle between the central axis 1a of the radiation source 1 and a perpendicular line perpendicular to the surface of the first sheet portion w1 is φ3 (=90°-φ1), and the length of the irradiated area in the non-analysis target layer b2 viewed from a direction perpendicular to the central axes 1a and 2a of the radiation source 1 and the radiation detector 2 is d. irr2 , the length of the detection region in the non-analyte is d det2 The radiation source 1 and the radiation detector 2 are arranged so as to satisfy the following formula (1).

[0033] X tanφ3-dirr2 / 2>d det2 / twenty one)

[0034] By arranging the radiation source 1 and the radiation detector 2 so as to satisfy such formula (1), it is possible to ensure that secondary radiation generated in the analysis target layer b1 formed in the first sheet portion w1 is incident on the radiation detector 2, while preventing secondary radiation generated in the non-analysis target layer b2 formed in the second sheet portion w2 from being incident on the radiation detector 2.

[0035] According to the radiation analysis system 300 of this embodiment configured in this manner, secondary radiation generated in the analysis target layer b1, which is located at the forefront of the multiple layers, can be made to enter the radiation detector 2, while secondary radiation generated in at least one non-analysis target layer b2, which is located behind the analysis target layer b1, can be prevented from entering the radiation detector 2. This makes it possible to prevent secondary radiation generated from layers not to be analyzed from being detected, thereby reducing the adverse effects thereof.

[0036] The present invention is not limited to the above-described embodiment. For example, in other embodiments, as shown in FIG. 2, the radiation detector 2 does not have to be positioned so that the angle φ2 between the central axis 2a of the detection field of view and the surface of the first sheet portion w1 is 90°, and may be positioned so that the central axis 2a of the detection field of view is oblique to the surface of the first sheet portion w1.

[0037] In other embodiments, the radiation source 1 may not include the emission angle limiting element 11, and the radiation detector 2 may not include the view angle limiting element 21.

[0038] In the above embodiment, the radiation source 1 and the radiation detector 2 are arranged such that the in-plane direction of the plane including their respective central axes 1a, 2a is approximately parallel to the movement direction of the conveying device 200; however, this is not limited thereto. In other embodiments, the radiation source 1 and the radiation detector 2 may be arranged such that the in-plane direction of the plane including their respective central axes 1a, 2a intersects with the movement direction of the conveying device 200. It is only necessary that the radiation source 1 and the radiation detector 2 are arranged in such a direction that the distance between the first sheet portion w1 and the second sheet portion w2 of the moving workpiece W does not vary significantly.

[0039] Further, the radiation analysis system 300 of another embodiment may analyze a workpiece W that is not transported (moved) by the transport device 200.

[0040] Furthermore, in the above embodiment, the workpiece W is in the form of a sheet, but is not limited to this. In other embodiments, the workpiece W may be a laminate in which a plurality of layers are stacked.

[0041] In the above embodiment, the workpiece W has a coating layer formed only on one surface of the base material a, but this is not limited thereto. In another embodiment, for example, as shown in FIG. 3, the workpiece W may have a coating layer formed on both one surface and the other surface (rear surface) of the base material a. In this case, the radiation source 1 and the radiation detector 2 may be arranged so that secondary radiation generated in the coating layer b (layer to be analyzed) formed on one surface (the surface facing the radiation source 1 and the radiation detector 2) of the workpiece W is incident on the radiation detector 2, and secondary radiation generated in the coating layer c (layer not to be analyzed) formed on the other surface (i.e., the rear surface) is not incident on the radiation detector 2.

[0042] In another embodiment, the workpiece W may have one or more coating layers made of a material that does not generate secondary radiation even when irradiated with primary radiation. Even if such a coating layer that does not generate secondary radiation is formed on the layer to be analyzed, the effects of the present invention can be achieved.

[0043] In addition, the base material a in other embodiments is not limited to being made of a material that does not easily generate primary radiation. The base material a in other embodiments may be, for example, in a mesh shape and may be structurally configured to transmit the primary radiation.

[0044] Furthermore, the radiation analysis apparatus 100 of another embodiment may be configured to irradiate an electron beam as primary radiation and detect characteristic X-rays as secondary radiation.

[0045] In addition, various modifications and combinations of the embodiments may be made as long as they do not go against the spirit of the present invention. [Explanation of symbols]

[0046] 100...Radiation analyzer 1...radiation source 2. Radiation detector W ···Work b1: Analysis target layer b2...Non-analysis target layer

Claims

1. 1. A radiation analysis apparatus for analyzing a workpiece having a plurality of spaced apart layers that are irradiated with primary radiation and generate secondary radiation, comprising: a radiation source that irradiates primary radiation, the primary radiation spreading at a predetermined radiation angle, toward the surface of the workpiece from a direction intersecting the plurality of layers; a radiation detector facing the surface of the workpiece and detecting secondary radiation generated from the workpiece; a radiation analyzing apparatus in which the radiation source and the radiation detector are disposed such that, as viewed from the radiation source and the radiation detector, secondary radiation generated in a predetermined analysis target layer among the plurality of layers is incident on the radiation detector, and secondary radiation generated in at least one non-analysis target layer located deeper than the analysis target layer is not incident on the radiation detector.

2. an area of ​​the analysis target layer where the primary radiation is irradiated by the radiation source and a detection area where the secondary radiation can be detected by the radiation detector overlap; The radiation analysis apparatus according to claim 1 , wherein the irradiation region and the detection region do not overlap in the non-analysis target layer.

3. 3. The radiation analysis device according to claim 1, wherein the radiation detector comprises: a detection element that detects the secondary radiation; and a view-angle limiting element that is disposed in front of the detection element and limits a view angle at which the secondary radiation can be detected by the detection element.

4. 3. The radiation analyzing apparatus according to claim 1, wherein the radiation source includes a radiation angle limiting element that limits a radiation angle of the primary radiation.

5. 3. The radiation analysis apparatus according to claim 1, wherein the workpiece is transported in a predetermined transport direction.

6. The workpiece has a plurality of sheet portions that are sheet-shaped and face each other with a gap between them, the analysis target layer is formed on a surface of a front sheet portion that is located nearest to the radiation source and the radiation detector among the plurality of sheet portions, 3. The radiation analysis device according to claim 1, wherein the non-analysis layer is formed on a surface of a rear sheet portion of the plurality of sheet portions that is located rearward of the front sheet portion.

7. the radiation source emits X-rays as the primary radiation, the radiation detector detects fluorescent X-rays as the secondary radiation, 3. The radiation analysis apparatus according to claim 1, wherein the fluorescent X-rays generated from the analysis target layer are detected to quantitatively analyze elements contained in the analysis target layer.

8. The radiation analysis apparatus according to claim 1 or 2, wherein the workpiece is analyzed to measure the film thickness or deposition amount of the analysis target layer.

9. 1. A method of radiological analysis for analyzing a workpiece having a plurality of spaced apart layers irradiated with primary radiation and generating secondary radiation, the method comprising: irradiating a surface of the workpiece with primary radiation from a radiation source in a direction intersecting the plurality of layers, the primary radiation spreading at a predetermined radiation angle; Detecting secondary radiation generated from the workpiece with a radiation detector facing the surface of the workpiece; the radiation source and the radiation detector are disposed so that, as viewed from the radiation source and the radiation detector, secondary radiation generated in a predetermined analysis target layer among the plurality of layers is incident on the radiation detector, and secondary radiation generated in at least one non-analysis target layer located deeper than the analysis target layer is not incident on the radiation detector.

10. The radiation analysis device according to claim 1 or 2; a conveying device that conveys the workpiece along a predetermined conveying direction.

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