X-ray inspection equipment

Abstract

Provided is an X-ray inspection device that, when inspecting an object having a layered structure, can acquire an X-ray transmission image in which the layered structure is displayed with sufficient brightness and resolution. [Solution] The X-ray inspection device includes a support unit that supports an object having a layered structure, an X-ray generation unit that irradiates the object with X-rays, and an X-ray detection unit that detects the X-rays that have passed through the object. The X-ray generation unit has an electron gun that emits an electron beam E and a target 76 that emits X-rays in response to the incidence of the electron beam E. When viewed from the Y-axis direction in which the object and the target 76 face each other, the shape of the electron beam irradiation area R on the target 76 is an elongated shape with a longitudinal direction D2 that intersects with the layering direction D1 of the layered structure.

Description

[Technical Field]

[0001] The present invention relates to an X-ray inspection device. [Background technology]

[0002] An X-ray inspection device is known that includes a support unit that supports an object, an X-ray generation unit that irradiates the object with X-rays, and an X-ray detection unit that detects the X-rays that have passed through the object, in which the X-ray generation unit has an electron source that emits an electron beam and a target that emits X-rays in response to the incidence of the electron beam (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-107307 Summary of the Invention [Problem to be solved by the invention]

[0004] In the X-ray inspection device described above, it is common to control the shape of the X-ray focal point, i.e., the shape of the electron beam irradiation area on the target, so that it is circular when viewed from the object side, so that the resolution of the acquired X-ray transmission image does not vary depending on the direction (for example, so that there is no difference between the vertical resolution and the horizontal resolution in the acquired X-ray transmission image).It has been found that when such an X-ray inspection device is used to inspect an object having a layered structure, resolution can be obtained, but brightness may be insufficient.

[0005] Therefore, the object of the present invention is to provide an X-ray inspection device that can obtain an X-ray transmission image in which the layered structure is displayed with sufficient brightness and resolution when inspecting an object having a layered structure. [Means for solving the problem]

[0006] The X-ray inspection device of the present invention is [1] "an X-ray inspection device comprising: a support section for supporting an object having a layered structure; an X-ray generation section for irradiating X-rays onto the object; and an X-ray detection section for detecting the X-rays that have passed through the object, wherein the X-ray generation section has an electron source for emitting an electron beam and a target for emitting the X-rays in response to the incidence of the electron beam; and wherein the shape of the electron beam irradiation area on the target is an elongated shape whose longitudinal direction is a direction intersecting the layering direction of the layered structure when viewed from a direction in which the object and the target face each other."

[0007] In the above-described X-ray inspection device, the shape of the electron beam irradiation area on the target, when viewed from the direction in which the object and the target face each other, is elongated, with the longitudinal direction being a direction intersecting the stacking direction of the stacked structure. As a result, the width of the electron beam irradiation area in the stacking direction of the stacked structure is small when viewed from the object side. Therefore, sufficient resolution can be obtained in the X-ray transmission image in the stacking direction of the stacked structure. Furthermore, when comparing an electron beam irradiation area that has an elongated shape with the longitudinal direction intersecting the stacking direction of the stacked structure when viewed from the object side with an electron beam irradiation area that has a circular shape when viewed from the object side, if the widths of the electron beam irradiation area in the stacking direction of the stacked structure are equal in the elongated electron beam irradiation area and the circular electron beam irradiation area, the resolution of the X-ray transmission image in the stacking direction of the stacked structure is equal. However, the width of the electron beam irradiation area in the direction intersecting the stacking direction of the stacked structure is larger in the elongated electron beam irradiation area than in the circular electron beam irradiation area. Therefore, the amount of X-rays irradiated to the object is greater in an elongated electron beam irradiation area than in a circular electron beam irradiation area, and sufficient brightness can be obtained in the X-ray transmission image. Therefore, when an object having a layered structure is to be inspected, the X-ray inspection device can obtain an X-ray transmission image in which the layered structure is displayed with sufficient brightness and resolution.

[0008] The X-ray inspection device of the present invention may be [2] "the X-ray inspection device according to the above [1], in which the maximum width of the electron beam irradiation area in the longitudinal direction is at least twice the maximum width of the electron beam irradiation area in the direction perpendicular to the longitudinal direction." With this X-ray inspection device, it is possible to more reliably obtain an X-ray transmission image in which the layered structure is displayed with sufficient brightness and resolution.

[0009] The X-ray inspection device of the present invention may be [3] "the X-ray inspection device according to the above [1] or [2], wherein the target has a surface on which the electron beam irradiation area is formed, and a first angle formed between a first optical axis of the electron source passing through the electron beam irradiation area and the surface and a second angle formed between a second optical axis of the X-ray detection unit passing through the electron beam irradiation area and the surface are different from each other." With this X-ray inspection device, it is possible to realize a configuration in which the shape of the electron beam irradiation area when viewed from the target side is elongated with a simple configuration.

[0010] The X-ray inspection device of the present invention may be [4] "the X-ray inspection device according to any one of the above [1] to [3], wherein the X-ray generation unit further has an electron lens that shapes the electron beam so that the cross section of the electron beam passing through the electron beam irradiation area perpendicular to the first optical axis of the electron source has an elongated shape." This X-ray inspection device can reliably realize a configuration in which the shape of the electron beam irradiation area when viewed from the object side is elongated.

[0011] The X-ray inspection device of the present invention may be [5] "the X-ray inspection device according to any one of the above [1] to [4], wherein the object is a lithium-ion battery, and the lithium-ion battery, when supported by the support, has the stacked structure in which positive electrodes and negative electrodes are alternately arranged with separators interposed therebetween in a cross section perpendicular to the second optical axis of the X-ray detection unit passing through the electron beam irradiation area." With this X-ray inspection device, the stacked state of the positive electrodes and negative electrodes interposed between the separators can be confirmed with sufficient brightness and resolution in the acquired X-ray transmission image of the lithium-ion battery. [Effects of the Invention]

[0012] According to the present invention, when inspecting an object having a layered structure, it is possible to provide an X-ray inspection device that can obtain an X-ray transmission image in which the layered structure is displayed with sufficient brightness and resolution. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a configuration diagram of an example of an X-ray inspection device. [Figure 2] 2 is a partial cross-sectional view of the X-ray generating unit shown in FIG. 1. [Figure 3] 3 is a diagram showing an electron beam irradiation region formed on the target shown in FIG. 2. FIG. [Figure 4] FIG. 10 is a diagram showing the relationship between the shape of an electron beam irradiated region when viewed from the object side and the resolution of a laminated pattern in a comparative example. [Figure 5] FIG. 10 is a diagram showing the relationship between the shape of an electron beam irradiated region when viewed from the object side and the resolution of a laminated pattern in an example. [Figure 6] FIG. 10 is a diagram showing an electron beam irradiation area in a modified example. [Figure 7] FIG. 10 is a diagram showing an electron beam irradiation area in a modified example. [Figure 8] FIG. 10 is a diagram showing an electron beam irradiation area in a modified example. [Figure 9] FIG. 10 is a diagram showing an object in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0014] An example of the present invention will now be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and redundant explanations will be omitted.

[0015] As shown in FIG. 1, the X-ray inspection apparatus 1 includes a support unit 2, an X-ray generation unit 3, and an X-ray detection unit 4. The X-ray inspection apparatus 1 is an apparatus for obtaining an X-ray transmission image of an object S having a stacked structure S1 as an inspection target, and, as an example, obtains a CT (Computed Tomography) image of the object S. In this example, the object S is a lithium-ion battery 100A of a type known as a rectangular-shaped battery. In the lithium-ion battery 100A, a positive electrode 102 and a negative electrode 103 are stacked in one direction within a rectangular parallelepiped package 101 with a separator 104 interposed therebetween, thereby forming a stacked structure S1. In this case, this one direction is the stacking direction D1 of the stacked structure S1. Hereinafter, three mutually perpendicular directions will be referred to as the X-axis direction, the Y-axis direction, and the Z-axis direction. In this example, the Z-axis direction is the vertical direction, and the X-axis direction and the Y-axis direction are the horizontal directions.

[0016] The support part 2 supports the lithium ion battery 100A so that the stacking direction D1 coincides with the X-axis direction. The support part 2 is capable of rotating (spinning) around an axis perpendicular to the Z-axis direction. When acquiring a CT image of the lithium ion battery 100A, the lithium ion battery 100A is rotated by the rotation of the support part 2. As an example, the support part 2 is a support table on which the lithium ion battery 100A is placed, a holding mechanism that holds the lithium ion battery 100A, or the like.

[0017] The X-ray generation unit 3 irradiates the lithium ion battery 100A supported by the support unit 2 with X-rays from one side in the Y-axis direction. As shown in FIG. 2, the X-ray generation unit 3 includes an X-ray tube 7, a power supply unit 8, and a cylindrical member 9. The cylindrical member 9 has a first opening 9a and a second opening 9b. The first opening 9a and the second opening 9b face each other on a tube axis TA. The X-ray tube 7 is attached to the end of the cylindrical member 9 on the first opening 9a side. The power supply unit 8 is attached to the end of the cylindrical member 9 on the second opening 9b side. In this example, the tube axis TA is parallel to the Y-axis direction. Note that FIG. 2 shows cross sections of the cylindrical member 9 and the tip of a socket 84, which will be described later.

[0018] The power supply unit 8 is configured by embedding a high-voltage generating unit 82, a high-voltage wire 83, and the base end of a socket 84 in an insulating block 81. The insulating block 81 is formed of an insulating resin such as epoxy resin. The outer surface of the insulating block 81 is coated with a conductive paint to set the potential at the ground potential. The base end of the socket 84 is electrically connected to the high-voltage generating unit 82 via the high-voltage wire 83. The tip end of the socket 84 is disposed inside the cylindrical member 9 via the second opening 9b and is located on the tube axis TA.

[0019] In the X-ray tube 7, a vacuum housing is formed by the bulb 71, head 72, and side tube 73. The bulb 71 is disposed inside the cylindrical member 9 via the first opening 9a, and the head 72 is disposed outside the cylindrical member 9 on the opposite side of the bulb 71 from the power supply unit 8. In this state, a flange 72a provided on the head 72 is attached to the end of the cylindrical member 9 on the first opening 9a side. The side tube 73 is connected to the side wall of the head 72 so that its center line intersects (e.g., is perpendicular to) the tube axis TA. A window member 74 is provided on the top wall of the head 72. The window member 74 is located on the tube axis TA. As an example, the bulb 71 is formed of an insulating material such as glass, and the head 72 and side tube 73 are formed of a conductive material such as metal.

[0020] In the X-ray tube 7, an anode member 75 extends along the tube axis TA inside the bulb 71 and the head 72. The anode member 75 has a tip surface 75a on the window member 74 side and a base end 75b on the opposite side from the window member 74. The anode member 75 airtightly penetrates the bottom wall of the bulb 71. The base end 75b of the anode member 75 is electrically and physically connected to the tip of a socket 84 of the power supply unit 8 outside the bulb 71. A target 76 is provided on the tip surface 75a of the anode member 75. The target 76 is formed into a film shape from tungsten, for example. The tip surface 75a of the anode member 75 is inclined so as to face an electron gun (electron source) 77 and the window member 74. The electron gun 77 is housed in the side tube 73. The electron gun 77 emits an electron beam. The target 76 emits X-rays in response to the incidence of the electron beam.

[0021] In the X-ray generating unit 3, the power supply unit 11 is configured by the socket 84. The power supply unit 11 is disposed inside the cylindrical member 9 and is electrically connected to a part of the X-ray tube 7 (in this example, the base end 75b of the anode member 75). In the X-ray generating unit 3, the cylindrical member 9 and the power supply unit 8 configure the housing unit 12. That is, the housing unit 12 includes the cylindrical member 9 and the power supply unit 8. The housing unit 12 houses a part of the X-ray tube 7 (in this example, the bulb 71 and the base end 75b of the anode member 75) and the socket 84 so as to be located within the insulating oil IO.

[0022] In the X-ray generation unit 3 configured as above, as an example, the head 72 and side tube 73 are set to ground potential, while a positive voltage is applied to the anode member 75 and target 76 by the power supply unit 8. In this state, when the electron beam emitted from the electron gun 77 is focused on the target 76, X-rays are emitted from the electron beam irradiation region on the target 76, and the X-rays are emitted to the outside with the electron beam irradiation region as a focal point after passing through the window member 74. In this way, the X-ray tube 7 is configured as a reflection type X-ray tube.

[0023] As shown in FIG. 1, the X-ray detection unit 4 faces the X-ray generation unit 3 in the Y-axis direction. The X-ray detection unit 4 detects X-rays emitted from the X-ray generation unit 3 and transmitted through the lithium-ion battery 100A. As an example, the X-ray detection unit 4 is an indirect conversion type X-ray detector and includes a scintillator and a photodetector array. The scintillator emits light in response to incident X-rays. The photodetector array is disposed on the opposite side of the scintillator from the X-ray generation unit 3 and detects the light emitted by the scintillator. Note that the X-ray detection unit 4 may also be a direct conversion type X-ray detector.

[0024] As shown in FIGS. 1, 2, and 3, the shape of the electron beam irradiation region R on the target 76 of the X-ray generation unit 3 is an elongated shape with the longitudinal direction D2 intersecting the stacking direction D1 of the stacked structure S1 when viewed from the Y-axis direction in which the lithium-ion battery 100A and the target 76 face each other. In other words, the support unit 2 supports the lithium-ion battery 100A so that the "shape of the electron beam irradiation region R when viewed from the target S side" is an "elongated shape with the longitudinal direction D2 intersecting the stacking direction D1 of the stacked structure S1." As shown in FIG. 3(a), in this example, the maximum width W1 of the electron beam irradiation region R in the longitudinal direction D2 is at least twice the maximum width W2 of the electron beam irradiation region R in the direction perpendicular to the longitudinal direction D2. As an example, W1 is 20 to 40 μm, and W2 is 10 to 20 μm. FIG. 3(a) shows the shape of the electron beam irradiation region R when viewed from the target object S side.

[0025] Here, the term "long shape" refers to a shape (e.g., an elliptical shape, an oval shape, a rectangular shape, etc.) in which the maximum width in one direction is greater than the maximum width in a direction perpendicular to the one direction, and the longitudinal direction refers to the one direction. In this example, the electron beam E traveling toward the target 76 is focused into a cone shape with the first optical axis A1 of the electron gun 77 as the center line. In this example, the shape of the electron beam irradiation area R when viewed from the target S side is elliptical, and its longitudinal direction D2 coincides with the Z-axis direction.

[0026] As shown in FIG. 3B, a first angle θ1 formed between a first optical axis A1 of the electron gun 77, which passes through the electron beam irradiation region R, and the surface 76a of the target 76, and a second angle θ2 formed between a second optical axis A2 of the X-ray detection unit 4, which passes through the electron beam irradiation region R, and the surface 76a of the target 76 are different from each other. The surface 76a is the surface of the target 76 where the electron beam irradiation region R is formed. In this example, the surface 76a of the target 76 and the tip surface 75a of the anode member 75 are inclined so that the second angle θ2 is smaller than the first angle θ1. In this example, the second optical axis A2 of the X-ray detection unit 4 coincides with the tube axis TA of the X-ray tube 7. Note that, as shown in FIG. 1, the lithium-ion battery 100A, when supported by the support unit 2, has a stacked structure S1 in which positive electrodes 102 and negative electrodes 103 are alternately arranged with separators 104 interposed therebetween in a cross section perpendicular to the second optical axis A2 of the X-ray detection unit 4.

[0027] As described above, in the X-ray inspection device 1, the shape of the electron beam irradiation region R when viewed from the object S side is an elongated shape with the longitudinal direction D2 being a direction intersecting the stacking direction D1 of the stacked structure S1. As a result, the width of the electron beam irradiation region R in the stacking direction D1 of the stacked structure S1 is small when viewed from the object S side. Therefore, sufficient resolution can be obtained in the X-ray transmission image in the stacking direction D1 of the stacked structure S1. Furthermore, comparing an electron beam irradiation region R that has an elongated shape with a longitudinal direction D2 intersecting the stacking direction D1 of the stacked structure S1 when viewed from the object S side with an electron beam irradiation region R that has a circular shape when viewed from the object S side, if the elongated electron beam irradiation region R and the circular electron beam irradiation region R have the same width in the stacking direction D1 of the stacked structure S1 (for example, if the diameter of the circular electron beam irradiation region R is W2), the resolution of the X-ray transmission image in the stacking direction D1 of the stacked structure S1 will be the same. However, the width of the electron beam irradiation region R in the direction intersecting the stacking direction D1 of the stacked structure S1 is larger in the elongated electron beam irradiation region R than in the circular electron beam irradiation region R (the width is W2 in the circular electron beam irradiation region R, but is W1 in the elongated electron beam irradiation region R). Therefore, the amount of X-rays irradiated onto the object S is greater in the elongated electron beam irradiation region R than in the circular electron beam irradiation region R, and sufficient brightness can be obtained in the X-ray transmission image. Therefore, when the object S having the layered structure S1 is the inspection target, the X-ray inspection device 1 can obtain an X-ray transmission image in which the layered structure S1 is displayed with sufficient brightness and resolution. Furthermore, when the shape of the electron beam irradiation region R when viewed from the object S side is sufficient to be the same as when it is circular, it is possible to suppress the energy density of the electron beam E in the electron beam irradiation region R. In this case, the life of the target 76 can be extended.

[0028] FIG. 4 is a diagram showing the relationship between the shape of the electron beam irradiation region R as viewed from the target S and the resolution of the stacked pattern in a comparative example. As shown in FIGS. 4(a) and 4(b), when the shape of the electron beam irradiation region R as viewed from the target S is circular, sufficient resolution can be obtained for both stacked patterns whose stacking directions D1 are perpendicular to each other. However, in this case, if the high-intensity electron beam E is focused on a small area on the target 76 to obtain sufficient brightness, the target's lifespan may be shortened. The stacked pattern is a black and white stripe pattern with a width of 10 μm, and the diameter of the electron beam irradiation region R is 20 μm.

[0029] FIG. 5 is a diagram showing the relationship between the shape of the electron beam irradiation region R when viewed from the object S side and the resolution of the laminated pattern in an embodiment. As shown in FIG. 5(a), when the shape of the electron beam irradiation region R when viewed from the object S side is elliptical and the longitudinal direction D2 of the electron beam irradiation region R coincides with the stacking direction D1 of the laminated pattern, sufficient resolution is not obtained. On the other hand, as shown in FIG. 5(b), when the shape of the electron beam irradiation region R when viewed from the object S side is elliptical and the longitudinal direction D2 of the electron beam irradiation region R is perpendicular to the stacking direction D1 of the laminated pattern, sufficient resolution is obtained. The laminated pattern is a black and white stripe pattern with a width of 10 μm, and the lengths of the major and minor axes of the electron beam irradiation region R are 40 μm and 20 μm, respectively.

[0030] In the X-ray inspection device 1, the maximum width W1 of the electron beam irradiation region R in the longitudinal direction D2 is at least twice the maximum width W2 of the electron beam irradiation region R in the direction perpendicular to the longitudinal direction D2. This makes it possible to more reliably obtain an X-ray transmission image in which the stacked structure S1 is displayed with sufficient brightness and resolution.

[0031] In the X-ray inspection device 1, the first angle θ1 that the first optical axis A1 of the electron gun 77 makes with the surface 76a of the target 76 and the second angle θ2 that the second optical axis A2 of the X-ray detection unit 4 makes with the surface 76a of the target 76 are different from each other. This makes it possible to realize a simple configuration in which the shape of the electron beam irradiation region R when viewed from the object S side is elongated.

[0032] In the X-ray inspection device 1, when a lithium ion battery 100A as an object S is supported by a support part 2, the lithium ion battery 100A has a stacked structure S1 in which positive electrodes 102 and negative electrodes 103 are alternately arranged with separators 104 interposed therebetween in a cross section perpendicular to the second optical axis A2 of the X-ray detection part 4. This makes it possible to confirm the stacked state of the positive electrodes 102 and negative electrodes 103 with the separators 104 interposed therebetween with sufficient brightness and resolution in the acquired X-ray transmission image of the lithium ion battery 100A.

[0033] The present invention is not limited to the above example. For example, as shown in FIG. 6(b), the surface 76a of the target 76 may be inclined so that the second angle θ2 is greater than the first angle θ1. In this case, when the electron beam E traveling toward the target 76 is focused conically around the first optical axis A1 of the electron gun 77, the shape of the electron beam irradiation area R when viewed from the target S side becomes elliptical, as shown in FIG. 6(a), and its longitudinal direction D2 coincides with the X-axis direction. In the example shown in FIG. 6, the support unit 2 may support the lithium-ion battery 100A so that the stacking direction D1 of the stacked structure S1 intersects with the longitudinal direction D2 (e.g., so that the stacking direction D1 of the stacked structure S1 coincides with the Z-axis direction). In the example shown in FIG. 6, as in the example shown in FIG. 3, the second optical axis A2 of the X-ray detection unit 4 coincides with the tube axis TA of the X-ray tube 7.

[0034] 7(b), the second optical axis A2 of the X-ray detection unit 4 does not have to coincide with the tube axis TA of the X-ray tube 7. In the example shown in FIG. 7, on a plane including the first optical axis A1 of the electron gun 77 and the second optical axis A2 of the X-ray detection unit 4, the tube axis TA is inclined with respect to the second optical axis A2 in the opposite direction to the first optical axis A1. That is, in the example shown in FIG. 7, the X-ray tube 7 is disposed so that the tube axis TA is inclined with respect to the second optical axis A2 in the opposite direction to the first optical axis A1. In this case, when the electron beam E traveling toward the target 76 is focused in a conical shape with the first optical axis A1 of the electron gun 77 as the center line, the shape of the electron beam irradiation region R when viewed from the object S side becomes elliptical, as shown in FIG. 7(a), and its longitudinal direction D2 coincides with the X-axis direction. 7, the support 2 supports the lithium-ion battery 100A so that the stacking direction D1 of the stacked structure S1 intersects with the longitudinal direction D2 (for example, so that the stacking direction D1 of the stacked structure S1 coincides with the Z-axis direction). In the example shown in Fig. 7, the first angle θ1 and the second angle θ2 are different from each other, as in the examples shown in Fig. 3 and Fig. 6.

[0035] 8(b), an electron lens 78 may be disposed between the electron gun 77 and the target 76. The electron lens 78 shapes the electron beam E so that the cross section of the electron beam E perpendicular to the first optical axis A1 of the electron gun 77 has an elongated shape. This reliably realizes a configuration in which the shape of the electron beam irradiation region R when viewed from the target S side is elongated. For example, even if the first angle θ1 and the second angle θ2 are equal to each other, as shown in FIG. 8(a), the shape of the electron beam irradiation region R when viewed from the target S side is elongated with the longitudinal direction D2 intersecting the stacking direction D1 of the stacked structure S1. The electron lens 78 is, for example, an electric field lens using electrodes, a magnetic field lens using coils, or the like.

[0036] 9, the target object S may be a lithium-ion battery 100B of a type known as a cylindrical battery. In the lithium-ion battery 100B, a positive electrode 102 and a negative electrode 103 are wound with a separator 104 interposed therebetween within a cylindrical package 101, thereby forming a stacked structure S1. In this case, any radial direction (i.e., any direction perpendicular to the center line CL) of the positive electrode 102 and the negative electrode 103 wound with the separator 104 interposed therebetween is the stacking direction D1 of the stacked structure S1. In the example shown in FIG. 1, the support 2 may support the lithium-ion battery 100B so that the center line CL is parallel to the Z-axis direction. In this case, when the lithium-ion battery 100B is supported by the support 2, the stacked structure S1 can be said to have a structure in which the positive electrodes 102 and the negative electrodes 103 are alternately arranged with the separator 104 interposed therebetween in a cross section perpendicular to the second optical axis A2 of the X-ray detection unit 4.

[0037] Furthermore, the X-ray tube 7 is not limited to being configured as a reflection-type X-ray tube, and may be configured as a transmission-type X-ray tube. As an example, in a transmission-type X-ray tube 7, an electron gun 77 is disposed inside a bulb 71, and a target 76 is provided on the inner surface of a window member 74. In this case, the target 76 is set at ground potential, and a negative voltage is applied to the electron gun 77 by a power supply unit 8. In this state, when an electron beam emitted from the electron gun 77 is focused on the target 76, X-rays are emitted from an electron beam irradiation region on the target 76, and the X-rays are emitted to the outside with the electron beam irradiation region as a focal point after passing through the window member 74. Furthermore, the X-ray generation unit 3 does not need to have a power supply unit 8. In this case, a high voltage may be supplied to the X-ray tube 7 from the outside via a high-voltage cable. [Explanation of symbols]

[0038] 1...X-ray inspection device, 2...support part, 3...X-ray generation part, 4...X-ray detection part, 76...target, 76a...surface, 77...electron gun (electron source), 78...electron lens, 100A, 100B...lithium ion battery, 102...positive electrode, 103...negative electrode, 104...separator, A1...first optical axis, A2...second optical axis, D1...stacking direction, D2...longitudinal direction, E...electron beam, R...electron beam irradiation area, S...object, S1...stacking structure, W1, W2...maximum width, θ1...first angle, θ2...second angle.

Claims

1. a support portion that supports an object having a laminated structure; an X-ray generating unit that irradiates the object with X-rays; an X-ray detection unit that detects the X-rays that have passed through the object, The X-ray generating unit an electron source that emits an electron beam; a target that emits the X-rays in response to the electron beam being incident thereon, An X-ray inspection device in which the shape of the electron beam irradiation area on the target is an elongated shape with its longitudinal direction intersecting the stacking direction of the stacked structure when viewed from a direction in which the object and the target face each other.

2. 2. The X-ray inspection apparatus according to claim 1, wherein a maximum width of the electron beam irradiation area in the longitudinal direction is at least twice as large as a maximum width of the electron beam irradiation area in a direction perpendicular to the longitudinal direction.

3. the target has a surface on which the electron beam irradiation region is formed, 2. The X-ray inspection device according to claim 1, wherein a first angle formed by a first optical axis of the electron source passing through the electron beam irradiation area and the surface, and a second angle formed by a second optical axis of the X-ray detection unit passing through the electron beam irradiation area and the surface are different from each other.

4. 2. The X-ray inspection apparatus according to claim 1, wherein the X-ray generation unit further comprises an electron lens that shapes the electron beam so that a cross-sectional shape of the electron beam perpendicular to a first optical axis of the electron source passing through the electron beam irradiation region is elongated.

5. the target object is a lithium ion battery, The X-ray inspection device according to any one of claims 1 to 4, wherein, when the lithium ion battery is supported by the support portion, the stacked structure has a structure in which positive electrodes and negative electrodes are alternately arranged via separators in a cross section perpendicular to a second optical axis of the X-ray detection portion that passes through the electron beam irradiation area.

Images