WO2016190074A1

WO2016190074A1 - Reflective x-ray generation device

Info

Publication number: WO2016190074A1
Application number: PCT/JP2016/063792
Authority: WO
Inventors: 和哉熊本; 定好松田
Original assignee: 松定プレシジョン株式会社
Priority date: 2015-05-27
Filing date: 2016-05-09
Publication date: 2016-12-01
Also published as: JP6121072B1; JPWO2016190074A1

Abstract

Provided is a reflective X-ray generation device with which it is possible to adequately minimize any reduction in quality of a target. A reflective X-ray generation device is provided with: a chamber (10) constituting part of an interior space (IS) that extends in at least a z-axis direction; an electron gun (20) secured to the chamber (10) in the interior space (IS), the electron gun (20) irradiating a target (13) with electron rays; and an adjustment unit (82) for adjusting the angle of inclination, with respect to the z-axis direction, of the electron rays irradiated from the electron gun (20). The chamber (10) includes a window (12) via which X-rays emitted from the target (13) are led out of the interior space (IS).

Description

Reflective X-ray generator

The present invention relates to a reflective X-ray generator, and more specifically to a reflective X-ray generator capable of sufficiently suppressing target quality degradation.

Conventionally, X-ray imaging is used for diagnosis in the medical field and non-destructive inspection in the industrial field.

An X-ray generator that generates X-rays includes an electron gun that emits electrons (electron beams), a lens electrode that focuses the electrons emitted from the electron gun, a target that generates X-rays when the electrons collide, It has. The X-ray generator collides electrons emitted from an electron gun with a target, and generates X-rays from the target by the collision energy. The generated X-ray is radiated to an external object through the window. There are two types of X-ray generators, a transmission type and a reflection type. The transmission type is a method in which X-rays are extracted from the same direction as the traveling direction of the electron beam from the electron gun toward the target. The reflection type is a method in which X-rays are extracted from a direction different from the traveling direction of the electron beam from the electron gun toward the target.

In the transmission type, the target is held at a position in contact with the window, whereas in the reflection type, the target is held at a position away from the window. Therefore, the reflection type can cool the target more easily than the transmission type. Therefore, in the reflection type, the intensity of the electron beam can be increased, and more sensitive X-ray imaging can be performed.

In recent years, a technique for applying an electron beam emitted from an electron source to a desired position on a target has been proposed. For example, Patent Document 1 below discloses a transmission X-ray tube that houses an electron gun for generating an electron beam in a vacuum vessel. In this X-ray tube, the vacuum vessel includes a vacuum vessel main body, a target, a target support that supports the target, and a connecting body that connects the vacuum vessel main body and the target support. The coupling body is airtightly fixed to each of the vacuum vessel main body and the target support body, and allows displacement of the target support body with respect to the vacuum vessel main body. The target support can be tilted with respect to the axis of the electron beam generated by the electron gun, and the direction of tilting along the circumferential direction around the axis of the electron beam can be changed.

In Patent Document 2 below, an electron gun that emits electrons from the cathode in the direction of electron incidence, an anode made of a reflective target that emits X-rays by making the emitted electrons incident on the target surface, and a target are provided. A reflection type X-ray tube including an electron shielding means for shielding electrons reflected from a target surface is disclosed.

JP 2011-113705 A JP 2004-111336 A

However, the technique of Patent Document 1 relates to a transmission type. The transmission type target has a problem that it is difficult to cool the target as compared with the reflection type. Therefore, miniaturization of the electron beam convergence size and increase of the electron beam energy have a problem of shortening the life of the target. Moreover, since the connection body is increased in size, the irradiation position of the electron beam on the target cannot be changed in a wide range, and the deterioration of the quality of the target cannot be sufficiently prevented. In the conventional reflection type X-ray generator as in Patent Document 2, since the irradiation position of the electron beam on the target is always the same, there is a problem that the quality of the target is significantly deteriorated.

The present invention is for solving the above-described problems, and an object of the present invention is to provide a reflection type X-ray generator capable of sufficiently suppressing a reduction in target quality.

A reflective X-ray generator according to one aspect of the present invention includes a chamber constituting an internal space extending in at least one direction, an electron gun that is supported by the chamber in the internal space and irradiates an electron beam to a target, The chamber includes a window for guiding X-rays generated from the target to the outside of the internal space.

Preferably, the reflection type X-ray generator further includes an expansion / contraction portion that can be expanded / contracted by an external force, the electron gun is supported by the chamber via the expansion / contraction portion, and the adjustment portion locally expands / contracts the expansion / contraction portion. Let

In the reflection type X-ray generator, preferably, the electron gun is fixed and further includes a fixing base connected to the expansion / contraction part, and the chamber is a bottom part provided at a position sandwiching the electron gun and the fixing base between the window and the window. The elastic part is supported by the bottom part.

Preferably, in the reflection type X-ray generator, the adjustment unit includes a pushing unit that pushes the fixed base in a direction to locally increase the distance between the electron gun and the bottom.

Preferably, in the above reflection type X-ray generator, the adjustment unit includes a pulling unit that pulls the fixed base in a direction to locally reduce the distance between the electron gun and the bottom.

Preferably, in the reflection type X-ray generation device, the chamber further includes a head portion having a length in a direction perpendicular to the one direction along one direction, and the window is fixed to the head portion. .

Preferably, in the reflection type X-ray generator, the head portion includes a shape in which an upper portion of the cylinder is cut by at least the first surface and the second surface, and a window is provided on the first surface. The first surface is a plane, and the second surface forms a boundary line with the first surface.

Preferably, in the reflection type X-ray generation device, the head portion includes a shape in which an upper portion of the cylinder is further cut by a third surface, and the second and third surfaces are both flat surfaces, The surface forms a boundary line with the first surface, and the second surface and the third surface are symmetric with respect to a plane including the rotation axis of the cylinder.

Preferably, in the reflection type X-ray generator, the adjustment unit locally decreases the distance between the electron gun and the bottom and a push screw that pushes the fixing base in a direction to locally increase the distance between the electron gun and the bottom. And a pulling screw for pulling the fixing base in the direction to be fixed, and the fixing base is fixed by the push screw and the pulling screw.

In the reflection type X-ray generator, the area of the window portion exposed to the outside is preferably not less than 0.5 square millimeters and not more than 20 square millimeters.

Preferably, in the reflection X-ray generator, the target includes a substrate made of a light element material and a heavy metal material formed on a surface of the substrate that is irradiated with an electron beam.

In the reflective X-ray generator, the minimum value of the distance from the surface irradiated with the electron beam to the outer surface of the window is preferably 0.1 mm or more and 4 mm or less.

In the reflective X-ray generator, the minimum value of the distance from the surface irradiated with the electron beam to the outer surface of the window is preferably 0.2 mm or more and 2 mm or less.

In the above reflection type X-ray generator, the minimum value of the distance from the surface irradiated with the electron beam to the outer surface of the window is preferably 0.3 mm or more and 1.5 mm or less.

In the reflective X-ray generator, the focal diameter is preferably larger than 0 and not larger than 5 μm.

According to the present invention, it is possible to sufficiently suppress the target quality deterioration.

It is sectional drawing which shows schematic structure of the X-ray imaging apparatus in one embodiment of this invention. It is sectional drawing which shows the 1st structure of the X-ray generator in one embodiment of this invention. It is a top view which shows the structure of the expansion-contraction part 30 at the time of seeing from the lower side in FIG. 2 and the fixed base lower end part 52a. It is sectional drawing which shows the 2nd structure of the X-ray generator in one embodiment of this invention. It is a top view which shows the structure of the expansion-contraction part 30 at the time of seeing from the lower side in FIG. 4 and the fixed stand lower end part 52a. It is sectional drawing which shows the 3rd structure of the X-ray generator in one embodiment of this invention. It is a top view which shows the structure of the expansion-contraction part 30 at the time of seeing from the lower side in FIG. 6, and the fixing stand lower end part 52a. It is a perspective view which shows the 1st structure of the head part in one embodiment of this invention. It is a perspective view which shows the 2nd structure of the head part in one embodiment of this invention. It is a perspective view at the time of seeing from the 1st direction which shows the 3rd structure of the head part in one embodiment of this invention. It is a perspective view at the time of seeing from the 2nd direction which shows the 3rd structure of the head part in one embodiment of this invention. It is a figure which shows typically the positional relationship of the head part 11 and the workpiece | work WK when the boundary line with another surface does not exist in the vicinity of plane PL1 in which the window 12 is provided. It is a figure which shows typically the positional relationship of the head part 11 and the workpiece | work WK in case the boundary line LN1 with plane PL2 or curved surface CS2 exists in the vicinity of plane PL1 in which the window 12 is provided. 9A schematically shows the plane PL1 of FIG. 9, and schematically shows the positional relationship between the point where the arrow AR2 passes through the window 12 in FIG. 13 and the shortest distance D11 between the boundary line LN1. FIG. (B) is a schematic representation of the plane PL1 surface of FIG. 9, and the area of the window exposed to the outside is (a) by bringing the position of the arrow AR2 closer to the substantially triangular tip of the plane PL1. It is a figure which shows typically the positional relationship in the case of making it smaller than the case of. When the boundary line LN1 with the plane PL2 or the phase CS2 exists in the vicinity of the plane PL1 where the window 12 is provided, the head portion 11 when the area of the window exposed to the outside is smaller than in the case of FIG. It is a figure corresponding to FIG.14 (b) which shows the positional relationship of a workpiece | work WK typically.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[Schematic configuration of X-ray imaging apparatus]

First, a schematic configuration of an X-ray imaging apparatus according to an embodiment of the present invention will be described.

FIG. 1 is a cross-sectional view showing a schematic configuration of an X-ray imaging apparatus according to an embodiment of the present invention. Note that FIG. 1 shows the X-ray direction that coincides with the normal direction of the outer surface of the window among the traveling direction of the electron beam from the electron gun to the target (arrow AR1) and the X-ray emission direction from the window to the workpiece WK. It is sectional drawing at the time of seeing in the cross section containing the advancing direction (arrow AR2). The z-axis direction indicates the traveling direction of the electron beam (the direction indicated by the arrow AR1), and the z1 axis direction indicates the normal direction of the outer surface of the window (the direction indicated by the arrow AR2). Each of the x-axis, y-axis, and z-axis is assumed to be orthogonal to each other. Furthermore, it is assumed that the x1 axis, the y axis, and the z1 axis are orthogonal to each other.

Referring to FIG. 1, the X-ray imaging apparatus of the present embodiment includes an X-ray generation apparatus 1, an X-ray detection apparatus 70, a control unit 80, an operation unit 90, and the like. The workpiece WK to be subjected to inspection and X-ray irradiation is arranged so that the normal line of the plane of the workpiece WK facing the X-ray generation device 1 side is parallel to the normal line of the outer surface of the window. The arrow AR2 indicates the traveling direction of the X-ray that coincides with the normal direction of the outer surface of the window in the X-ray emission direction. The workpiece WK may be arranged such that the normal line of the plane of the workpiece WK facing the X-ray generator 1 side is inclined with respect to the normal line of the outer surface of the window. The workpiece WK may be a flat plate or a size that protrudes from the window. The work WK may be arranged in contact with the window.

The X-ray generator (X-ray source) 1 is a reflective X-ray generator. In the X-ray generator 1, the chamber 10 is a sealed type and constitutes a decompressed internal space IS. The internal space IS extends in the z-axis direction. The electron gun 20 is supported by the chamber 10 in the internal space IS. The X-ray generator 1 generates X-rays from the target by irradiating the target with an electron beam as indicated by an arrow AR1 from the electron gun 20 in the internal space IS. X-rays generated from the target spread radially, are guided to the outside of the internal space IS from the window 12 provided in the chamber 10, and are irradiated onto the work WK. An arrow AR4 indicates the traveling direction of the end portion of the X-ray that spreads radially. The lower part of the X-ray generator 1 is arranged in the case 100. A power source 101 is provided in the case 100. The bottom of the chamber 10 and the electron gun 20 are maintained at a high voltage by the power source 101, and the case 100 is maintained at the ground potential. The case 100 is filled with an insulating gas or resin for the purpose of preventing discharge.

The X-ray detection device 70 receives the X-ray that has passed through the workpiece WK, and transmits a signal indicating the intensity of the received X-ray to the control unit 80.

The control unit 80 is electrically connected to each of the X-ray generation apparatus 1, the X-ray detection apparatus 70, and the operation unit 90, and controls the entire X-ray imaging apparatus. The control unit 80 includes an X-ray generation control unit 81, a position angle adjustment unit 82, and an image generation unit 83.

The X-ray generation control unit 81 controls the voltage applied to the parts constituting the electron gun 20 and the lens of the X-ray generation apparatus 1 and the degree of vacuum inside the X-ray generation apparatus 1 to thereby control the X-ray generation apparatus 1. Controls X-rays generated from.

The position angle adjustment unit 82 adjusts the position (X-ray irradiation position) and the desired angle (X-ray irradiation angle) of the work WK by moving or tilting the work WK. The position angle adjustment unit 82 rotates the X-ray generation device 1 and the X-ray detection device 70 around the irradiation position of the electron beam on the target or the workpiece WK, thereby adjusting the position and angle desired to view the workpiece WK. You may do. Further, the position angle adjustment unit 82 may adjust the position of the workpiece WK to be seen and the angle to be seen by moving the X-ray detection device 70 along the x1 axis direction or the y axis direction.

The image generation unit 83 generates an X-ray image of the work WK based on the signal received from the X-ray detection device 70.

The operation unit 90 receives various operations related to the X-ray imaging apparatus from the operator, and transmits a signal based on the received operation to the control unit 80.

[Configuration of X-ray generator]

Subsequently, the configuration of the X-ray generator in one embodiment of the present invention will be described.

FIG. 2 is a cross-sectional view showing a first configuration of the X-ray generator in one embodiment of the present invention.

Referring to FIG. 2, the X-ray generator 1 having the first configuration includes a chamber 10, an electron gun 20, a telescopic unit 30, an adjustment unit 40, an electrode 51, a fixed base 52, and the like. . Each of the electron gun 20, the telescopic part 30, and the fixed base 52 is provided in the internal space IS of the chamber 10. Each of the adjustment unit 40 and the electrode 51 is provided on the bottom 14 of the chamber 10.

The chamber 10 includes a head part (anode) 11, a window (X-ray extraction window) 12, a target 13, a bottom part 14, a main body 15, metal plates (joining rings) 16a and 16b, and the like. The internal space IS of the chamber 10 has at least a degree of vacuum (for example, a degree of vacuum of 1 × 10 ⁻⁴ Pa or less) such that electrons can fly between the electron gun 20 and the target 13. The degree of vacuum of the internal space IS is preferably set as appropriate in consideration of the type of the electron gun 20 to be used, the operating temperature of the electron gun 20, and the like.

The head portion 11 is fixed to the work WK side (upper side in FIG. 2) of the main body 15. The head part 11 is fixed to the metal plate 16a by a method such as welding, and the metal plate 16a is fixed to the main body 15 by a method such as brazing. The head unit 11 and the target 13 are kept at the ground potential (GND potential) during electron beam irradiation. For example, the head portion 11 is tapered such that the length in the direction perpendicular to the z-axis direction (the length in the x-axis direction or the y-axis direction) decreases toward the upper side in FIG. 2 along the z-axis direction. It has a shape. It is preferable that the head part 11 has a substantially polygonal cone shape or a substantially conical tip. The head portion 11 is made of a metal such as copper, for example.

The window 12 is fixed near the position closest to the workpiece WK in the head portion 11. The window 12 closes a hole 11 a provided between the internal space IS and the outside of the head portion 11. The outer surface of the window 12 is a flat surface and has a normal line in the z1 axis direction. The outer surface of the window 12 and the outer surface of the head portion 11 are substantially on the same plane. The window 12 has a higher X-ray transmittance than the head unit 11. The window 12 is made of Be (beryllium), SiN (silicon nitride), SiC (silicon carbide), diamond-like carbon, or the like. The window 12 has a shape such as a circular plate, a square plate, or a trapezoidal plate. The thickness of the window 12 is, for example, not less than 0.01 mm and not more than 1 mm, preferably not less than 0.05 mm and not more than 0.5 mm, and more preferably not less than 0.1 mm and not more than 0.3 mm. The area of the window 12 exposed to the outside is preferably 0.5 square millimeters or more and 20 square millimeters or less. By setting the area of the window 12 exposed to the outside to 0.5 square millimeters or more, the X-ray radiation angle can be secured. The head part 11 can be reduced in size by setting the area of the window 12 exposed to the outside to 20 square millimeters or less.

The target 13 is fixed to a portion of the head portion 11 facing the internal space IS. The target 13 is close to the window 12. One end of the target 13 is close to the joint between the window 12 and the head portion 11. The target 13 is an X-ray generation source that generates X-rays when irradiated with an electron beam. The target 13 is usually made of a heavy metal having an atomic number of 26 or more. The target 13 preferably has a high thermal conductivity and a high melting point. Specifically, the target 13 is made of W (tungsten), Ta (tantalum), Rh (rhodium), Mo (molybdenum), Cr (chromium), or the like. The thickness of the target 13 is, for example, 0.1 μm or more and 1 mm or less.

The target 13 may be formed on one surface of the substrate by a method such as sputtering or vapor deposition, and may be fixed to the head portion 11 by bonding the other surface of the substrate to the inner wall surface of the head portion 11. The substrate in this case is made of a light element material such as diamond-like carbon, diamond, graphite sheet, or beryllium. The target 13 may be formed of a thin film produced by rolling or polishing. The thickness of the target 13 is, for example, not less than 0.1 μm and not more than 3 μm. In the case where the target 13 has a heavy metal formed on one surface (surface irradiated with an electron beam) made of a light element, the thickness of the substrate is such that electrons of the electron beam stop in the substrate. It is preferable to have. The intensity of X-rays generated from heavy metals is greater than the intensity of X-rays generated from light elements. By doing in this way, the magnitude | size of the X-ray generation part in the target 13 can be made small.

The bottom portion 14 is fixed to the opposite side (lower side in FIG. 2) of the work WK in the main body 15. The bottom portion 14 is provided at a position where the electron gun 20 and the fixed base 52 are sandwiched between the bottom portion 14 and the window 12. The bottom part 14 is fixed to the metal plate 16b by a method such as welding, and the metal plate 16b is fixed to the main body 15 by a method such as brazing. The bottom 14 is made of a metal such as stainless steel. A plurality of holes 14a are opened at the center of the bottom portion 14, and a plurality of electrodes 51 are inserted into each of the plurality of holes 14a. An insulating material such as glass is buried between the electrode 51 and the bottom portion 14 so as to be airtight. Each of the plurality of electrodes 51 is for supplying a potential or electric power to the electron gun 20.

The main body 15 has a cylindrical shape, and has an opening on each of the workpiece WK side and the opposite side of the workpiece WK. The opening on the workpiece WK side is covered with the head portion 11 and the window 12. The opening on the opposite side of the workpiece WK is covered by the bottom 14. The main body 15 insulates the electron gun 20 from the target 13 (head portion 11). The main body 15 is made of an insulator such as ceramic.

The electron gun 20 is fixed to a cylindrical fixed base 52. The electron gun 20 is supported on the bottom portion 14 via the telescopic portion 30 and the fixed base 52. The electron gun 20 is kept at a negative potential during electron beam irradiation. The electron gun 20 may be a thermal electron cathode, a tungsten filament, a crystal electron source such as a LaB6 cathode, or a field emission type such as cold FE or thermal FE.

The electron gun 20 includes a lens (not shown) for extracting and converging electrons generated from the electron gun 20 into the internal space IS. The lens of the electron gun 20 may be an electrostatic lens type or a magnetic lens type.

FIG. 3 is a plan view showing the configuration of the telescopic part 30 and the fixed base lower end part 52a when viewed from the lower side in FIG. 3, 5, and 7, the portion of the fixing base lower end portion 52 a that contacts the push screw 41 is indicated by a triangular symbol, and the portion of the fixing base lower end portion 52 a that contacts the pull screw 42 is a rectangular shape. It is indicated by a symbol.

Referring to FIGS. 2 and 3, the fixing base 52 includes a fixing base lower end portion 52a having a circumferential planar shape when viewed from the z-axis direction. The elastic part 30 is connected to the fixed base lower end part 52 a and is supported by the bottom part 14. The expansion / contraction part 30 can be expanded and contracted by an external force. The expansion / contraction part 30 extends from the fixed base lower end 52a to the inner diameter side (the electrode 51 side in FIG. 2) and reaches the bottom 14 and the outer diameter side (main body in FIG. 2) from the fixed base lower end 52a. 15 side) and an outer diameter side portion 30b reaching the bottom portion 14.

The adjusting unit 40 locally expands and contracts the expansion and contraction unit 30 to thereby change the inclination angle of the electron beam (direction indicated by the arrow AR1) irradiated from the electron gun 20 with respect to the extending direction (z-axis direction) of the internal space IS. Adjust. The adjustment part 40 includes a push screw 41 (an example of a push part) and a pull screw 42 (an example of a pull part). Each of the push screw 41 and the pull screw 42 is, for example, three. The push screw 41 is screwed into a hole 14 b provided in the bottom portion 14. A thread is formed on the inner wall of the hole 14b. The pull screw 42 is inserted into a hole 14 c provided in the bottom portion 14. The hole 14c is a through hole, and no thread is formed on the inner wall of the hole 14c. The head portion of the pull screw 42 is in contact with the peripheral surface of the hole 14 c in the bottom portion 14. Each of the push screw 41 and the pull screw 42 is provided alternately at equal intervals along the circumferential shape of the edge of the fixed base lower end 52a.

When the push screw 41 is rotated in the direction of entering the hole 14b, the push screw 41 pushes the lower end 52a of the fixed base away from the bottom 14. Thereby, the expansion / contraction part 30 in the vicinity of the position where the push screw 41 presses the fixed base lower end 52a is locally extended, and the distance between the electron gun 20 and the fixed base 52 and the bottom 14 is the same as the distance between the push screw 41 and the fixed base lower end It becomes locally large near the position where the portion 52a is pressed.

The tip of the pull screw 42 is screwed into a groove 52b provided in the lower end 52a of the fixed base. When the pull screw 42 is rotated in a direction to enter the fixed base lower end portion 52 a, the head portion of the pull screw 42 is in contact with and pressed against the bottom portion 14. Therefore, the pull screw 42 pulls the fixed base lower end portion 52 a toward the bottom portion 14. Thereby, the expansion / contraction part 30 near the position where the pulling screw 42 pulls the fixed base lower end part 52a is locally contracted, and the distance between the electron gun 20 and the fixing base 52 and the bottom part 14 is that the pulling screw 42 is at the lower end of the fixed base. It becomes locally smaller in the vicinity of the position where the portion 52a is pulled.

For example, when the push screw 41 on the right side in FIG. 2 is rotated in the direction to enter the hole 14b and the pull screw 42 on the left side in FIG. 2 is rotated in the direction to enter the groove 52b, the electron gun 20 is moved by the arrow M1. The electron beam trajectory also changes in the direction indicated by the arrow M11 (the tilt angle of the electron beam increases). As a result, the electron beam irradiation position on the target 13 changes, and the distance (minimum FOD) between the electron beam irradiation position on the target 13 and the atmosphere-side surface of the window 12 changes. 2 is rotated in a direction in which the pull screw 42 on both sides of the right push screw 41 in FIG. 2 enters the groove 52b, and the push screw 41 on both sides in the left pull screw 42 in FIG. 2 is rotated in a direction to enter the hole 14b. In such a case, the electron gun 20 is tilted in the direction indicated by the arrow M2, and the locus of the electron beam is also changed in the direction indicated by the arrow M12 (the tilt angle of the electron beam is increased). As a result, the electron beam irradiation position on the target 13 changes, and the distance (minimum FOD) between the electron beam irradiation position on the target 13 and the atmosphere-side surface of the window 12 changes.

After adjusting the electron gun 20 to a target angle, the push screw 41 applies a pressing force to the fixed base 52 so that the angle does not tilt, and the pull screw 42 pulls the fixed base 52. Each of the push screw 41 and the pull screw 42 applies a force to the fixing base 52 in directions opposite to each other along the circumferential direction of the fixing base lower end portion 52a. Thereby, the fixing base 52 is stably fixed. As a result, it is possible to prevent the tilt of the electron gun 20 from changing unnecessarily due to vibration or the like.

FIG. 4 is a cross-sectional view showing a second configuration of the X-ray generator in one embodiment of the present invention. FIG. 5 is a plan view showing the configuration of the telescopic part 30 and the fixed base lower end part 52a when viewed from the lower side in FIG.

4 and 5, in the X-ray generator 1 having the second configuration, the internal space IS of the chamber 10 is configured by the chamber 10, the extendable part 30, and the fixed base 52. The bottom part 14 has an annular shape. The main body 15 is made of an insulator such as glass.

The fixed base 52 is cylindrical and includes a fixed base lower end 52a having a circular planar shape when viewed from the z-axis direction. The fixed base lower end 52 a covers one opening in the cylindrical shape of the fixed base 52. Four holes 52c are opened in the fixed base lower end 52a, and each of the four electrodes 51 is inserted into each of the four holes 52c. Each hole 52c of the electrode 51 is provided with an insulating material such as glass so as to airtightly fill the space between the fixed base lower end 52a and the electrode 51.

The configuration other than the above in the X-ray generator 1 of the second configuration and the method of tilting the electron gun 20 are the same as in the case of the X-ray generator of the first configuration. The same reference numerals are given and description thereof will not be repeated.

FIG. 6 is a cross-sectional view showing a third configuration of the X-ray generator in one embodiment of the present invention. FIG. 7 is a plan view showing the configuration of the telescopic part 30 and the fixed base lower end part 52a when viewed from the lower side in FIG.

6 and 7, in the X-ray generator 1 having the third configuration, the internal space IS of the chamber 10 is configured by the chamber 10, the telescopic portion 30, and the fixed base 52. A main body 15 of the chamber 10 is integrated with the head portion 11. The main body 15 and the head unit 11 may be separated from each other. The main body 15 may be made of, for example, stainless steel, and the head portion 11 may be made of, for example, a metal such as copper. The chamber 10 is an open type. The main body 15 is provided with an opening 15a, and a vacuum pump 60 is connected to the opening 15a. Thereby, the opening 15a can be opened to the atmosphere, and the electron gun 20 and the like can be exchanged. The bottom part 14 is airtightly fixed with screws or the like with a copper gasket or an O-ring sandwiched between the main body 15 and the like. The bottom part 14 has an annular shape. The head portion 11 and the main body 15 are made of a metal such as copper, for example.

The fixed base 52 has a truncated cone shape, and includes a fixed base lower end 52a having a circumferential planar shape when viewed from the z-axis direction. The fixed base 52 insulates the electron gun 20 from the target 13 (main body 15). A part of the fixed base 52 (part other than the fixed base lower end 52a) is made of an insulator such as ceramic. Four holes 52c are opened in the fixed base lower end 52a, and each of the four electrodes 51 is inserted into each of the four holes 52c. The elastic part 30 is connected to the fixed base lower end part 52 a and is supported by the bottom part 14. The stretchable part 30 has a bellows shape. The expansion / contraction part 30 is arrange | positioned in the position which overlaps with the fixed stand lower end part 52a, when it sees from a z-axis direction.

The configuration other than the above in the X-ray generator 1 of the third configuration and the method of tilting the electron gun 20 are the same as in the case of the X-ray generator of the first configuration. The same reference numerals are given and description thereof will not be repeated.

The configuration of the X-ray generator may be any of the first to third configurations described above, or may be a combination of the members in each of the first to third configurations described above. The configuration of the X-ray generator may be other than the first to third configurations described above.

[Appearance of head section]

Subsequently, the external shape of the head portion in one embodiment of the present invention will be described.

FIG. 8 is a perspective view showing a first configuration of the head portion according to the embodiment of the present invention.

Referring to FIG. 8, the head portion 11 of the first configuration includes a shape in which the upper part of the cylinder is cut by a plurality of surfaces. The tip of the head part 11 has a substantially polygonal pyramid shape. The head unit 11 includes planes PL1 and PL2 that are planes for cutting a cylinder, and a curved surface CS1 that is a side surface of the cylinder. Window 12 is provided in the vicinity of the tip of head portion 11 on plane PL1. The normal lines of the planes PL1 and PL2 are inclined with respect to the cylindrical rotation axis OA. The plane PL1 and the plane PL2 are adjacent to each other at the boundary line LN1. The boundary line LN1 is linear and is located at the most distal end (position closest to the workpiece WK) in the head portion 11. Each of planes PL1 and PL2 has a substantially semicircular planar shape.

FIG. 9 is a perspective view showing a second configuration of the head portion according to the embodiment of the present invention.

Referring to FIG. 9, the head portion 11 having the second configuration also includes a shape in which the upper part of the cylinder is cut by a plurality of surfaces. The tip of the head part 11 has a substantially polygonal pyramid shape. The head unit 11 includes planes PL1, PL2, PL3, and PL4 that are planes for cutting a cylinder, and a curved surface CS1 that is a side surface of the cylinder. Window 12 is provided in the vicinity of the tip of head portion 11 on plane PL1. Each normal of the planes PL1, PL2, PL3, and PL4 is inclined with respect to the rotation axis OA of the cylinder, and each of the planes PL1, PL2, PL3, and PL4 surrounds the rotation axis OA of the cylinder. Is arranged. The plane PL1 and the plane PL2 are adjacent by a boundary line LN1, the plane PL1 and the plane PL3 are adjacent by a boundary line LN2, the plane PL2 and the plane PL4 are adjacent by a boundary line LN3, and the plane PL3 And the plane PL4 are adjacent to each other at the boundary line LN4. Each of the boundary lines LN1, LN2, LN3, and LN4 is linear. Each of planes PL1, PL2, PL3, and PL4 has a substantially triangular planar shape. The plane PL1 and the plane PL2 are symmetric with respect to the plane PL10 including the cylindrical rotation axis OA.

FIG. 10 and FIG. 11 are perspective views showing a third configuration of the head portion in one embodiment of the present invention.

Referring to FIG. 10 and FIG. 11, the head portion 11 having the third configuration also includes a shape in which the upper part of the cylinder is cut by a plurality of surfaces. The tip of the head part 11 has a substantially conical shape. The head unit 11 includes a plane PL1 that is a plane for cutting a cylinder, a curved surface CS2 that is a curved surface that cuts the cylinder into a conical shape, and a curved surface CS1 that is a side surface of the cylinder. Window 12 is provided in the vicinity of the tip of head portion 11 on plane PL1. The normal line of the plane PL1 is inclined with respect to the cylindrical rotation axis OA, and each of the plane PL1 and the curved surface CS2 is disposed so as to surround the cylindrical rotation axis OA. The plane PL1 and the curved surface CS2 are adjacent to each other at the boundary lines LN1 and LN2. Each of the boundary lines LN2 and LN3 is curved. The plane PL1 has a substantially triangular planar shape.

The configuration of the head portion may be any of the first to third configurations described above, or may be a configuration other than these. Each of the head portions having the first to third configurations may be applied to any of the above-described X-ray generators having the first to third configurations, and may be applied to an X-ray generator other than the above-described ones. Also good.

[Effects of the embodiment]

Next, the effect of this embodiment will be described.

According to the present embodiment, since the tilt angle of the electron beam can be adjusted, the irradiation position of the electron beam on the target 13 is changed in a wide range by a simpler method than when the target 13 is moved. be able to. As a result, the quality degradation of the target 13 can be sufficiently suppressed.

Further, when impurities are mixed in the window 12 (this phenomenon is likely to occur when the window 12 is made of Be), X-rays can be irradiated while avoiding the impurities, so that the quality of the captured image of the work WK can be improved. Decline can be suppressed.

Further, the FOD can be shortened to some extent by irradiating the target 13 closest to the window 12 with the electron beam.

Furthermore, since the tilt angle of the electron beam can be adjusted, the irradiation position of the electron beam on the target can be appropriately set in a wide range. Thereby, a window can be reduced in size and the size near the front-end | tip of a head part can be made small. As a result, the head unit 11 has a configuration in which a boundary line with another surface exists in the vicinity of the plane on which the window 12 is provided, particularly as in the configurations of the second and third head units. In the case of the configuration, the FOD can be reduced even in the state where the normal line on the X-ray irradiation side of the workpiece WK is inclined with respect to the normal line on the outer surface of the window 12 (z1 axis direction). The effect of reducing the FOD will be described in detail with reference to FIGS.

FIG. 12 is a diagram schematically showing the positional relationship between the head unit 11 and the workpiece WK when there is no boundary line with another surface near the plane PL1 where the window 12 is provided.

Referring to FIG. 12, the case where head portion 11 has a configuration in which no boundary line with another surface exists in the vicinity of plane PL1 where window 12 is provided is, for example, the tip of head portion 11 Is formed of a single plane (when the head portion 11 has a substantially cylindrical shape). In this case, when the normal line (arrow AR3) of the plane on the head portion 11 side of the workpiece WK is inclined with respect to the normal line (arrow AR2) of the outer surface of the window 13 (when the workpiece WK is tilted), it is indicated by a circle X1. At the position, the end of the work WK interferes with the head part 11, and the work WK cannot approach the target 13. As a result, FOD has a large value of distance D1.

FIG. 13 is a diagram schematically showing the positional relationship between the head portion 11 and the work WK when a boundary line LN1 between the plane PL2 or the curved surface CS2 exists in the vicinity of the plane PL1 where the window 12 is provided. is there.

Referring to FIG. 13, when there is a boundary line LN1 with plane PL2 or curved surface CS2 in the vicinity of plane PL1 where window 12 is provided, the boundary line is set so that work WK approaches plane PL2 or curved surface CS2. The workpiece WK can be tilted with LN1 as a fulcrum. Thereby, the workpiece | work WK can be made to approach the target 13 compared with the case of FIG. As a result, FOD has a value of distance D2 that is smaller than distance D1. In the case of FIG. 13, the shortest distance between the point where AR2 penetrates the window 12 exposed to the outside and the boundary line LN1 is the distance D11.

FIG. 14A shows the plane PL1 in FIG. 9, and the shortest distance D11 between the point where the arrow AR2 passes through the window 12 in FIG. 13 and the boundary line LN1 is drawn. FIG. 14B shows the position of the arrow AR2 at the substantially triangular tip of the plane PL1 when the boundary line LN1 with the plane PL2 or the phase CS2 exists in the vicinity of the plane PL1 where the window 12 is provided. It is a figure when the area of the window exposed outside becomes smaller than the case of FIG. 13 (FIG. 14 (a)) by approaching. The shortest distance D12 between the point where the arrow AR2 passes through the window 12 and the boundary line LN1 is drawn. It can be seen that the distance D12 can be shorter than the distance D11.

FIG. 15 shows a case where the area of the window exposed to the outside is smaller than in the case of FIG. 13 when the boundary line LN1 with the plane PL2 or the phase CS2 exists in the vicinity of the plane PL1 where the window 12 is provided. FIG. 15 is a view corresponding to FIG. 14B schematically showing the positional relationship between the head unit 11 and the workpiece WK.

Referring to FIG. 15, in head portion 11 of the second and third configurations of the present embodiment, boundary line LN1 with plane PL2 or curved surface CS2 exists in the vicinity of plane PL1 where window 12 is provided. is doing. In such a configuration, by making the area of the window 12 smaller than the conventional area (area in the case of FIG. 13) as described above, the point where the arrow AR2 passes through the window 12 exposed to the outside and the boundary line LN1 Is the distance D12 smaller than the distance D11. As a result, FOD has a value of distance D3 that is smaller than distance D2.

The distance D4 indicating the minimum FOD (the minimum value of the distance from the surface irradiated with the electron beam in the target 13 to the outer surface of the window 12) in the present embodiment is, for example, 0.1 mm or more and 4 mm or less, preferably It is 0.2 mm or more and 2 mm or less, More preferably, it is 0.3 mm or more and 1.5 mm or less, More preferably, it is 1 mm or more and 1.5 mm or less. In the conventional X-ray generator, the reproducibility of the assembly accuracy is poor and a large fluctuation occurs in the minimum FOD. However, by adding an electron beam angle adjustment function to the X-ray generator as in this embodiment. The minimum FOD can be adjusted with high accuracy as in the above range.

In the transmission type, the window 12 is typically used with a thickness of 0.5 mm. Therefore, the minimum FOD is 0.5 mm. On the other hand, the reflection type is typically used at about 10 mm. A case where the minimum FOD is, for example, about 1 mm to 1.5 mm will be described. In this case, it can be used without much difference compared to the transmission type. For example, when the thickness of the workpiece WK is 3 mm, the FOD including the thickness is 3.5 mm in the transmission type, and the FOD including the thickness is, for example, 4 mm to 4.5 mm in the present embodiment. Then there is no big difference. Further, since the X-ray dose can be increased by the amount that can be cooled in the reflective type, it is possible to realize an enlargement rate equivalent to that of the transmissive type by separating the X-ray detection device 70 compared to the transmissive type.

Furthermore, according to the present embodiment, the following effects can be obtained by reducing the FOD.

When the distance between the X-ray generator 1 and the X-ray detector 70 is the same as the distance in the conventional case, the geometric magnification of the captured image of the workpiece WK can be increased by reducing the FOD, The photographed image of the work WK can be enlarged and viewed.

When the geometric magnification is the same as the conventional case, the amount of received X-rays in the X-ray detection device 70 increases as the FOD decreases. As a result, when the amount of received X-ray light is reduced to the same extent as in the conventional case, the amount of electron beam colliding with the target 13 can be reduced. As a result, the spread of the electron beam can be reduced, and the size of the X-ray generation part in the target 13 can be reduced. That is, the resolution can be improved. Further, since the amount of electron beams can be reduced, damage to the target 13 can be reduced.

[Others]

The X-ray generator may be a microfocus type (having a focal diameter of 10 μm or less) in addition to a sealed type and an open type. When the X-ray generator is a microfocus type, the focal diameter is preferably 5 μm or less.

The adjustment unit may be provided on the side surface or the front surface of the chamber instead of being provided on the bottom surface.

The shape of the internal space formed by the chamber is arbitrary, and the internal space may have a plurality of extending directions. When the internal space has a plurality of extending directions, the adjusting unit may adjust the inclination angle of the electron beam emitted from the electron gun with respect to at least one extending direction of the internal space.

The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 X-ray generator 10 Chamber 11 Head part 11a Head part hole 12 Window 13 Target 14 Bottom part 14a, 14b, 14c Bottom part hole 15 Main body 15a Main body opening 16a, 16b Metal plate 20 Electron gun 30 Expansion / contraction part 30a Expansion / contraction part Inner diameter side portion 30b Outer diameter side portion of expansion / contraction portion 40 Adjustment portion 41 Push screw 42 Pull screw 51 Electrode 52 Fixing base 52a Fixing base lower end 52b Fixing base groove 52c Fixing base hole 60 Vacuum pump 70 X-ray detection device 80 Control Unit 81 X-ray generation control unit 82 Position angle adjustment unit 83 Image generation unit 90 Operation unit 100 Case 101 Power supply AR1 Arrow indicating the traveling direction of the electron beam AR2 Among the X-ray emission directions from the window to the workpiece, the window method Arrow indicating the direction of travel of X-rays that matches the line direction AR3 AR4 indicating the direction of the normal line of the plane on the side of the side AR4 Traveling direction of the end of the X-ray that spreads radially CS1, CS2 Curved surface D1, D2, D3, D4, D11, D12 Distance IS internal space LN1, LN2, LN3 LN4 Boundary line M1, M2 Arrow indicating the tilt direction of the electron gun M11, M12 Arrow indicating the direction in which the trajectory of the electron beam changes OA Cylindrical rotation axis PL1, PL2, PL3, PL4, PL10 Plane WK Work X1 End of work Where the head interferes with the head

Claims

A chamber constituting an internal space extending in at least one direction;
An electron gun that is supported by the chamber in the internal space and irradiates an electron beam to a target;
An adjustment unit for adjusting an inclination angle of the electron beam irradiated from the electron gun with respect to the one direction;
The reflection type X-ray generator, wherein the chamber includes a window for guiding X-rays generated from the target to the outside of the internal space.
It is further equipped with a stretchable part that can be stretched by external force,
The electron gun is supported by the chamber via the extendable part,
The reflective X-ray generation device according to claim 1, wherein the adjustment unit locally expands and contracts the expansion and contraction unit.
The electron gun is fixed, and further includes a fixing base connected to the extendable part,
The chamber further includes a bottom provided at a position sandwiching the electron gun and the fixed base between the window and the window,
The reflective X-ray generator according to claim 2, wherein the expandable portion is supported by the bottom portion.
The reflection type X-ray generation device according to claim 3, wherein the adjustment unit includes a pressing unit that pushes the fixed base in a direction to locally increase a distance between the electron gun and the bottom.
4. The reflection type X-ray generator according to claim 3, wherein the adjusting unit includes a pulling unit that pulls the fixed base in a direction to locally reduce a distance between the electron gun and the bottom.
The chamber further includes a head portion having a length in a direction perpendicular to the one direction along the one direction.
The reflective X-ray generator according to claim 1, wherein the window is fixed to the head portion.
The head portion includes a shape in which an upper portion of a cylinder is cut by at least a first surface and a second surface, the window is provided on the first surface, and the first surface is The reflection type X-ray generation device according to claim 6, wherein the reflection type X-ray generation device is a flat surface, and the second surface forms a boundary line with the first surface.
The head portion includes a shape in which an upper portion of a cylinder is further cut by a third surface, the second and third surfaces are both flat surfaces, and the third surface is the first surface. The reflective X-ray generator according to claim 7, wherein a boundary line is formed between the second surface and the third surface, and the second surface and the third surface are symmetric with respect to a plane including a rotation axis of the cylinder. .
The adjusting unit is
A push screw that pushes the fixed base in a direction to locally increase the distance between the electron gun and the bottom,
A pull screw for pulling the fixing base in a direction to locally reduce the distance between the electron gun and the bottom,
The reflective X-ray generator according to claim 3, wherein the fixing base is fixed by the push screw and the pull screw.
2. The reflection type X-ray generator according to claim 1, wherein an area of the portion of the window exposed to the outside is not less than 0.5 square millimeters and not more than 20 square millimeters.
2. The reflective X-ray generator according to claim 1, wherein the target includes a substrate made of a light element material and a heavy metal material formed on a surface of the substrate irradiated with an electron beam.
The reflection type X-ray generator according to claim 1, wherein the minimum value of the distance from the surface of the target irradiated with the electron beam to the outer surface of the window is 0.1 mm or more and 4 mm or less.
The reflection type X-ray generator according to claim 12, wherein the minimum value of the distance from the surface of the target irradiated with the electron beam to the outer surface of the window is 0.2 mm or more and 2 mm or less.
The reflection type X-ray generator according to claim 13, wherein the minimum value of the distance from the surface of the target irradiated with the electron beam to the outer surface of the window is 0.3 mm or more and 1.5 mm or less.
The reflection type X-ray generator according to claim 1, wherein the focal diameter is greater than 0 and 5 μm or less.