JP2013109937A - X-ray tube and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray tube capable of suppressing X-ray radiation caused by a brazing filler metal and radiating only a desired X-ray, and to provide a manufacturing method of the same.SOLUTION: The X-ray tube comprises: a substrate 103; a target 102 provided at one surface side of the substrate 103; an anode 108 bonded to a side face of the substrate 103 with a brazing filler metal; and a cathode which is disposed opposite to the target 102 and emits electrons and irradiates electrons onto the target 102. In the X-ray tube, at least a part of a peripheral region of the one surface side of the substrate 103 is a level difference which blocks the brazing filler metal 106 which flows out.

Description

  The present invention relates to an X-ray tube applied to diagnostic applications in the field of medical equipment and non-destructive X-ray imaging in the field of industrial equipment, and a method for manufacturing the same.

  In general, the X-ray tube accelerates electrons emitted from a cathode such as a filament directly or after controlling the trajectory by a control electrode toward an anode (anode) applied to the cathode at a high potential. The accelerated electrons collide with a target installed on the anode, and X-rays that are one type of radiation are generated. The generated X-rays are irradiated to the irradiated object through the window and imaged or inspected.

  The X-ray tube has an envelope in order to maintain a decompression space where electrons can fly. Further, the window for emitting the generated X-rays to the outside forms a part of the envelope and is vacuum-tightly joined to the surrounding envelope. As vacuum-tight joining, brazing is an effective means, and the method is disclosed in Patent Document 1. In Patent Document 1, in a transmission X-ray tube, amorphous carbon having a thickness of 0.2 mm is used as a window (outgoing window) that transmits X-rays, and a target metal such as W or Ti is formed on the vacuum side inner surface of the window. It is vapor-deposited and brazed with a brazing material (Ag is the main component) at its periphery.

JP-A-9-180660

  However, when the brazing material is heated to 780 ° C. to 900 ° C. in a vacuum, the brazing material melts and flows into the target surface. In particular, the metal surface on which W and Ti are vapor-deposited as the target has high fluidity of the brazing material, and covers a considerable portion of the target surface. When electrons collide with the target of the X-ray tube manufactured in such a state, unnecessary X-rays such as characteristic X-rays of brazing metal covering the target, such as Ag and Cu, are radiated. X-ray spectrum cannot be obtained.

  Therefore, an object of the present invention is to provide an X-ray tube capable of suppressing X-ray emission caused by the brazing material and emitting only desired X-rays, and a manufacturing method thereof.

In order to solve the above problems, the present invention provides a substrate, a target provided on one side of the substrate, an anode bonded to the side surface of the substrate with a brazing material, and opposed to the target, and emits electrons. A cathode that irradiates the target with the electrons;
An X-ray tube having
An X-ray tube is provided in which at least a part of a peripheral region of the one surface of the substrate is a step for blocking the brazing material that has flowed out.

  According to the present invention, at least a part of the peripheral region of the surface on which the target of the substrate is provided is a step that dams out the flowing brazing material. For this reason, the brazing material does not flow into the region of the target surface where electrons are irradiated, and only the desired X-rays originating from the target material can be emitted from the electrons that collide with the target.

It is sectional drawing of the target structure used for the X-ray tube of this invention, and an anode. It is sectional drawing which shows an example of a structure of (a) X-ray tube of this invention, and (b) It is sectional drawing which shows an example of a structure of an X-ray generator provided with an X-ray tube. It is sectional drawing of the target structure used for the X-ray tube of Example 2, and an anode. It is sectional drawing of the target structure used for the X-ray tube of Example 3, and an anode. 6 is a cross-sectional view of a target structure and an anode used for an X-ray tube of Example 4. FIG. 6 is a cross-sectional view of a target structure and an anode used in an X-ray tube of Example 5. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention does not receive a restriction | limiting at all by these structures including the member, shape, relative position, etc. which are described in the following embodiment. Moreover, the same code | symbol shows the same component in drawing referred below.

  First, a preferred embodiment of the X-ray tube of the present invention will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a cross-sectional view of a target structure and an anode used in the X-ray tube of this embodiment. In FIG. 1, the target structure 101 includes a target 102, a substrate 103 that supports the target 102, a metallized layer 104, and a barrier 107. By irradiating the target 102 with the electron beam 109, X-rays are generated from the target 102.

  The target 102 is formed on one surface of the substrate 103 by sputtering, vapor deposition, or the like. As a material of the target 102, W, Cu, Ta, Pt, Mo, Te, or an alloy thereof is preferably used. When the electron beam 109 collides with the target 102, the energy of the electron beam 109 is almost changed to thermal energy, so that the target 102 and the substrate 103 are heated. Accordingly, the material of the substrate 103 is required to have heat resistance, and ceramics, diamond, or other inorganic materials having insulating properties are preferably used. In the case where X-rays are emitted through the substrate 103, X-ray transparency is also required. In this case, ceramics, glass, diamond, beryllium, aluminum, graphite, or the like is preferably used.

  The substrate 103 is vacuum-tightly bonded to the anode 108 by brazing. When glass, graphite, ceramics, or the like is used as the material of the substrate 103, the side surface of the substrate 103 is subjected to a metallization process so that brazing can be performed more firmly and airtightly, and the metallized layer 104 having a metal and an intermediate layer. Is preferably formed. As a material constituting the metallized layer 104, a metal containing Ti, Mo—Mn, or the like is preferably used. The metallized layer 104 is not essential as a member constituting the X-ray tube of the present invention. The substrate 103 and the anode 108 are brazed by filling the brazing portion 105 with a brazing material, and the anode 108 is bonded to the side surface of the substrate 103 by the brazing material. In the case where the metallized layer 104 is formed on the side surface of the substrate 103, the anode 108 is bonded to the side surface of the substrate 103 through the metallized layer 104 with a brazing material. The brazing material is determined in consideration of the heat resistance of each of the target 102, the substrate 103, and the anode 108, and brazing is performed at a temperature suitable for the brazing material. When the brazing material BAg-8 (JIS standard) is used, brazing can be performed at 780 ° C. to 900 ° C., and brazing is performed in a vacuum, in an inert gas or a reducing gas atmosphere in order to prevent oxidation of the member. Is preferred.

  In order to ensure good vacuum tightness, it is necessary to penetrate the brazing material into a narrow space. For this reason, as the brazing material, one having high fluidity, particularly one having high fluidity on the metal surface is used. Therefore, in this embodiment, the barrier 107 is formed on the substrate 103 (precisely on the target 102) so that the brazing material does not flow into the region irradiated with the electron beam 109 on the surface of the target 102. Specifically, a barrier 107 is formed in the peripheral region of the surface of the substrate 103 on which the target 102 is provided, and the barrier 107 forms a step that dams out the brazing material that has flowed out. The barrier 107 may be provided in at least a part of the peripheral region of the surface of the substrate 103 where the target 102 is provided. However, the electron beam 109 is irradiated to the peripheral region of the surface of the substrate 103 where the target 102 is provided. More preferably, it is provided in an annular shape so as to surround the region.

  As the material of the barrier 107, a substance having non-affinity with the brazing material is preferably used. For example, ceramic adhesives such as Aron Ceramics (registered trademark), other inorganic materials mainly composed of ceramics, and inorganic materials having conductivity can be used. The height of the barrier 107 is preferably about 1 to 10 times the thickness of the brazing portion 105. When the barrier 107 that satisfies this height condition is formed, the brazing material 106 that has flowed out during brazing is prevented from entering inside by the barrier 107, and the brazing material does not flow into the region irradiated with the electron beam 109. Therefore, since the electron beam 109 does not collide with the brazing material 106 that has flowed out, characteristic X-rays caused by the brazing material are not generated. The barrier 107 is not essential as a member constituting the X-ray tube of the present invention. Regardless of the presence or absence of the barrier 107, the effect of the present invention can be obtained if at least a part of the peripheral region where the target 102 of the substrate 103 is provided is a step that dams out the brazing material 106 that has flowed out.

  In addition, when the X-ray tube is manufactured, the surface of the substrate 103 on which the target 102 and the barrier 107 are formed is faced upward (toward the anti-vertical direction), and the substrate 103 and the anode 108 are joined by brazing, so that The brazing material blocking effect (blocking effect) of the barrier 107 is increased.

  FIG. 2A is a cross-sectional view showing an example of the configuration of an X-ray tube including the target structure 101 and the anode 108 of FIG. In FIG. 2A, an X-ray tube 200 is a transmissive X-ray tube. The metal electron gun flange 204, the cylindrical insulator 205, and the anode 108 are vacuum-tightly joined at their respective joining surfaces to form an envelope 208 that can be decompressed. Brazing is suitable as the vacuum hermetic joining method.

  As a material of the insulator 205, glass or ceramics is preferably used, and alumina is a promising candidate in terms of insulation, vacuum tightness, thermal conductivity, and wettability with metal. The material of the electron gun flange 204 is determined in consideration of the material of the insulator 205. When the insulator 205 is alumina, the electron gun flange 204 is optimally kovar. A metal or the like is preferably used as the material of the anode 108, but the anode 108 does not have to be composed of one kind of metal. For example, when the thermal expansion coefficients of the insulator 205 and the substrate 103 are greatly different, metals having similar thermal expansion coefficients may be used as the anodes 108, respectively. In this case, the metals having similar coefficients of thermal expansion can be vacuum-tightly bonded to each other, and then the bonded metals can be vacuum-tightly bonded to the insulator 205 and the substrate 103. Brazing, welding, etc. are suitable as a vacuum-tight joining method between metals.

  An electron gun unit 201 is installed on the electron gun flange 204. In the electron gun unit 201, electrons are emitted from the cathode 202, and electrons emitted from the cathode 202 by the control electrode 203 are formed into an electron beam 109 having a desired trajectory and size and emitted toward the target 102. The cathode 202 and the control electrode 203 are disposed to face the target 102. As the cathode 202, a high melting point metal such as tungsten or rhenium, or a filament type cathode in which yttria or the like is applied on the surface thereof, a thermal field emission type cathode, an impregnation type cathode in which porous tungsten is impregnated with BaO as a main component, or the like Is applicable. In addition, a Spindt type, a carbon nanotube, a cold cathode represented by a surface conduction type, and the like are also applicable. Electric power and electric signals necessary for driving the electron gun unit 201 are generated by a driving power source 211 (see FIG. 2B), and a vacuum-tight voltage / current introducing unit 210 attached to the electron gun flange 204 is provided. Via the outside.

  An acceleration voltage generated by the drive power supply 211 is applied to the anode 108 in order to accelerate the electron beam 109. For this reason, it is preferable that the drive power supply 211 and the anode 108 are electrically connected, and further the anode 108 and the target 102 are electrically connected. As a method of electrically connecting the target 102 and the anode 108, for example, there is the following method. In the case where the target 102 is formed on the entire surface of one side of the substrate 103, there is a method in which the target 102 and the anode 108 are electrically connected to each other around the target 102 via a brazing material. When the target 102 is formed in a region excluding the peripheral region on one side of the substrate 103, a conductive member is formed in the peripheral region on the one surface of the substrate 103, and the target 102 and the anode 108 are electrically connected via the conductive member. There is a way to connect. When the target 102 is formed in a region excluding the peripheral region on one side of the substrate 103, a conductive barrier is formed in the peripheral region on the one surface of the substrate 103, and the target 102 is connected to the target 102 via the conductive barrier. There is also a method of electrically connecting the anode 108.

  A getter 209 may be provided inside the envelope 208 to maintain a vacuum as shown in FIG. As the getter 209, an evaporation type getter using Ba or a non-evaporation type getter made of an alloy made of a metal such as Zr, Ti, V, Fe, and Al can be used.

  FIG. 2B is a cross-sectional view showing an example of the configuration of the X-ray generator provided with the X-ray tube 200. In FIG. 2B, an X-ray tube 200 is installed in a container 213, and a driving power source 211 for driving the X-ray tube 200 is installed around the X-ray tube 200. The container 213 is filled with an insulating oil 214 to ensure a withstand voltage, and an X-ray circumscribing window 212 for radiating X-rays to the outside is attached to a part of the container 213. The electron beam 109 exiting the electron gun unit 201 is further accelerated by the voltage applied to the anode 108 and collides with the target 102. When the electron beam 109 collides with the target 102, a part of the energy of the electron beam 109 is emitted from the target 102 as X-rays, and the X-rays pass through the substrate 103, the insulating oil 214, and the X-ray circumscribed window 212 to the outside. Radiated and photographed or examined.

  Although FIG. 2 shows a transmissive X-ray tube, the present invention can also be applied to a reflective X-ray tube.

[Example 1]
In this example, an X-ray tube using the target structure 101 and the anode 108 shown in FIG. 1 was manufactured, and an X-ray generator equipped with the X-ray tube was manufactured.

  First, the target structure 101 shown in FIG. 1 was produced, and the produced target structure 101 and the anode 108 were brazed as shown in FIG. Specifically, it is as follows. Using SUMI-CRYSTAL manufactured by Sumitomo Electric Industries, Ltd., which is an artificial diamond having a diameter of 8 mm and a thickness of 2 mm as the substrate 103, the side surface of the substrate 103 was metallized with a Ti-containing paste to form a metallized layer 104. Next, Ti was applied to the entire surface of one side of the substrate 103 by sputtering, and W having a thickness of 10 μm was formed as the target 102. Subsequently, a barrier 107 made of Aaron ceramics manufactured by Toa Gosei Co., Ltd. having a width of 0.5 mm and a height of 0.5 mm from the center on the target 102 is formed in an annular shape, and the target structure 101 is formed. Completed. The barrier 107 was provided on the target, and a step was formed by the convex barrier 107. Thereafter, the target structure 101 is placed inside the Kovar anode 108, and a brazing material BA-108 manufactured by Toyo Riken Co., Ltd. is used in a vacuum atmosphere with the surface on which the barrier 107 is formed facing upward at 850 ° C. High temperature brazing was performed to form a brazing portion 105 and hermetically sealed in a vacuum. The brazing material 106 that flowed out was blocked by the barrier 107 and was not inside the barrier 107. Further, the target 102 and the anode 108 were electrically connected by the flowing brazing material 106.

  Next, the electron gun unit 201 shown in FIG. 2A was produced, and the produced electron gun unit 201, the electron gun flange 204, and the voltage / current introducing portion 210 were connected as shown in FIG. Specifically, it is as follows. An electron gun unit 201 was completed by using an impregnated cathode mainly composed of BaO as the cathode 202 and using an electrode made of Mo composed of two electrodes having a passage hole of φ2 mm as the control electrode 203. Thereafter, the electron gun unit 201 was fixed to the electron gun flange 204, and the vacuum-tight voltage / current introduction unit 210 and the electrodes of the electron gun unit 201 were connected. Further, as getter 209, Igun SAES Getters S. p. A non-evaporable getter ST172 manufactured by Company A was installed, and the heater built in the getter 209 and the voltage / current introduction unit 210 were connected.

  Subsequently, an insulator 205 shown in FIG. The insulator 205 has a cylindrical shape with a diameter of 50 mm and a thickness of 4 mm. The material is alumina, and both ends of the insulator 205 are metalized using a metal paste.

  Next, the envelope 208 shown in FIG. Specifically, it is as follows. An electron gun flange 204 on which an electron gun unit 201 and the like were installed, an anode 108 on which a target structure 101 was installed, and an insulator 205 were placed in a vacuum furnace. Then, the barrier 107 was disposed so as to face the cathode side, and brazing material BA-143 manufactured by Toyo Riken Co., Ltd. was used to perform low-temperature brazing at 700 ° C. in a vacuum atmosphere to complete the envelope 208. At the same time, a brazing material BA-143 was used, and a copper pipe (not shown) for vacuum exhaust of φ1 / 4 inch was brazed to the electron gun flange 204.

  Subsequently, the copper pipe was connected to an evacuation system (not shown), and the envelope 208 was baked to 400 ° C. while evacuating the inside of the envelope 208 to perform vacuum heat degassing treatment. Further, a driving power source (not shown) was connected to the voltage / current introducing unit 210 to heat the filament of the electron gun unit 201 and activate the cathode 202. Next, a voltage applying means (not shown) was connected to the anode 108, 1 kV was applied, an electron beam 109 of 10 mA was collided with the target 102 from the electron gun unit 201, and aging was performed for 48 hours. Thereafter, the getter 209 was energized and activated at 600 ° C., the copper pipe was chipped off, and the X-ray tube 200 shown in FIG. 2A was completed.

  Next, the produced X-ray tube 200 is installed in a container 213 having an X-ray circumscribing window 212 for extracting X-rays and filled with insulating oil 214, and a voltage / current introduction unit 210 and a driving power supply 211 are installed. And the anode 108 and the drive power supply 211 were connected. Thereafter, the container 213 was sealed to complete the X-ray generator shown in FIG.

  With respect to the produced X-ray generator, a voltage of 100 kV was applied to the anode 108, a current of 10 mA was passed through the anode 108, and its spectrum was measured with a semiconductor detector manufactured by AMPTEK, USA. The amount of characteristic X-rays (Ag: 22.2 keV, 24.9 keV, Cu: 8.0 keV, 8.9 keV) from Ag and Cu, which are the components of the brazing material 106 that flowed out, is 0.1% or less, which is a problem. It did not become.

[Example 2]
In this example, an X-ray tube using the target structure 101 and the anode 108 shown in FIG. 3 was manufactured, and an X-ray generator equipped with the X-ray tube was manufactured.

  First, the target structure 101 shown in FIG. 3 was produced, and the produced target structure 101 and the anode 108 were brazed as shown in FIG. Specifically, it is as follows. The substrate 103 is Sumitomo Electric Industries, Ltd., which is an artificial diamond having a diameter of 8 mm and a thickness of 2 mm. A laser having a width of 1 mm and a depth of 0.6 mm is positioned at a radius of 2.5 mm from the center of the substrate 103 by laser. The groove 307 was formed in an annular shape. Further, the side surface of the substrate 103 was metalized with a Ti-containing paste to form a metallized layer 104. Next, a 3 mm wide pyroduct 597C (made by Alemco) conductive paste was applied across the groove 307 and partly in contact with the target 102 and the metallized layer 104 to form a conductive member 310. Subsequently, Ti was pulled down by sputtering to the inner side of the groove 307 on the substrate 103, W having a thickness of 10 μm was formed as the target 102, and the target structure 101 was completed. A step was formed by the groove 307 provided on the substrate 103. Thereafter, the target structure 101 is placed inside the Kovar anode 108, and a brazing material BA-108 manufactured by Toyo Riken Co., Ltd. is used in a vacuum atmosphere with the surface on which the groove 307 is formed facing upward at 850 ° C. High temperature brazing was performed to form a brazing portion 105 and hermetically sealed in a vacuum. This brazing was performed in the same manner as in Example 1. The brazing material 106 that flowed out was blocked by the groove 307 and was not inside the groove 307. In addition, the target 102 and the anode 108 are electrically connected via the conductive member 310.

  Next, as in Example 1, the electron gun flange 204 and the insulator 205 on which the electron gun unit 201 and the like were installed were produced. Using the produced electron gun flange 204 and the insulator 205 and the anode 108 on which the target structure 101 produced by the above-described method is installed, the groove 307 is disposed so as to face the cathode side. Brazing was performed to complete the envelope 208 shown in FIG. Subsequently, as in Example 1, vacuum baking, aging, chip-off, etc. were performed to complete the X-ray tube 200 shown in FIG. Thereafter, in the same manner as in Example 1, an X-ray generator provided with this X-ray tube was produced.

  When the produced X-ray generator was evaluated by the same method as in Example 1, the amount of characteristic X-rays from Ag and Cu, which are the components of the brazing material 106 that flowed out, was 0.1% or less, which is a problem. It did not become.

[Example 3]
In this example, an X-ray tube using the target structure 101 and the anode 108 shown in FIG. 4 was manufactured, and an X-ray generator equipped with the X-ray tube was manufactured.

  First, the target structure 101 shown in FIG. 4 was produced, and the produced target structure 101 and the anode 108 were brazed as shown in FIG. Specifically, it is as follows. Using SUMI-CRYSTAL manufactured by Sumitomo Electric Industries, Ltd., which is an artificial diamond having a diameter of 8 mm and a thickness of 2 mm as the substrate 103, the side surface of the substrate 103 was metallized with a Ti-containing paste to form a metallized layer 104. Next, a sputtering method and a mask are used on the entire surface of one side of the substrate 103, a non-film formation region of φ3 mm is formed at the center on the substrate 103, Ti is subtracted, and then 0.2 μm of Mo is formed. Formed. A 10 μm thick W film with a diameter of 4 mm was formed thereon using a mask, and the target 102 was obtained. Subsequently, a barrier 107 made of Aaron ceramics manufactured by Toa Gosei Co., Ltd. having a width of 0.5 mm and a height of 0.5 mm is formed annularly at a position of a radius of 3 mm from the center on the substrate 103 to complete the target structure 101. It was. The barrier 107 was provided on the conductive member, and a step was formed by the convex barrier 107. Thereafter, the target structure 101 is placed inside the Kovar anode 108, and the surface on which the target 102 is formed is placed in a vacuum atmosphere using a brazing material BA-108 manufactured by Toyo Riken Co., Ltd. The brazing part 105 was formed and vacuum-tightly sealed. This brazing was performed in the same manner as in Example 1. The brazing material 106 that flowed out was blocked by the barrier 107 and did not enter the inside of the barrier 107. The conductive member 410 and the anode 108 are electrically connected by the flowing brazing material 106, and the target 102 and the conductive member 410 are electrically connected through the overlapping portion.

  Next, as in Example 1, the electron gun flange 204 and the insulator 205 on which the electron gun unit 201 and the like were installed were produced. Using the produced electron gun flange 204 and insulator 205 and the anode 108 provided with the target structure 101 produced by the above-described method, brazing was performed in the same manner as in Example 1, and the result is shown in FIG. The envelope 208 was completed. Subsequently, as in Example 1, vacuum baking, aging, chip-off, etc. were performed to complete the X-ray tube 200 shown in FIG. Thereafter, in the same manner as in Example 1, an X-ray generator provided with this X-ray tube was produced.

  When the produced X-ray generator was evaluated by the same method as in Example 1, the amount of characteristic X-rays from Ag and Cu, which are the components of the brazing material 106 that flowed out, was 0.1% or less, which is a problem. It did not become.

[Example 4]
In this example, an X-ray tube using the target structure 101 and the anode 108 shown in FIG. 5 was manufactured, and an X-ray generator equipped with the X-ray tube was manufactured.

  First, the target structure 101 shown in FIG. 5 was produced, and the produced target structure 101 and the anode 108 were brazed as shown in FIG. Specifically, it is as follows. Using SUMI-CRYSTAL manufactured by Sumitomo Electric Industries, Ltd., which is an artificial diamond having a diameter of 8 mm and a thickness of 2 mm as the substrate 103, the side surface of the substrate 103 was metallized with a Ti-containing paste to form a metallized layer 104. Next, a mask was used on one side of the substrate 103, Ti was subtracted by sputtering, and W having a diameter of 6 mm and a thickness of 10 μm was formed as the target 102. Subsequently, a conductive barrier 507 having a height of 0.5 mm was formed in an annular shape so as to be in contact with the metallized layer 104 and the target 102 using an inorganic conductive adhesive 597A manufactured by Alemco, and the target structure 101 was completed. . A step was formed by the convex conductive barrier 507. Thereafter, the target structure 101 is placed inside the Kovar anode 108, and the surface on which the target 102 is formed is placed in a vacuum atmosphere using a brazing material BA-108 manufactured by Toyo Riken Co., Ltd. The brazing part 105 was formed and vacuum-tightly sealed. This brazing was performed in the same manner as in Example 1. The brazing material 106 that flowed out was blocked by the conductive barrier 507 and did not enter the inside of the conductive barrier 507. Further, the target 102 and the anode 108 are electrically connected by the conductive barrier 507.

  Next, as in Example 1, the electron gun flange 204 and the insulator 205 on which the electron gun unit 201 and the like were installed were produced. Using the produced electron gun flange 204 and insulator 205 and the anode 108 provided with the target structure 101 produced by the above-described method, brazing was performed in the same manner as in Example 1, and the result is shown in FIG. The envelope 208 was completed. Subsequently, as in Example 1, vacuum baking, aging, chip-off, etc. were performed to complete the X-ray tube 200 shown in FIG. Thereafter, in the same manner as in Example 1, an X-ray generator provided with this X-ray tube was produced.

  When the produced X-ray generator was evaluated by the same method as in Example 1, the amount of characteristic X-rays from Ag and Cu, which are the components of the brazing material 106 that flowed out, was 0.1% or less, which is a problem. It did not become.

[Example 5]
In this example, an X-ray tube using the target structure 101 and the anode 108 shown in FIG. 6 was manufactured, and an X-ray generator equipped with the X-ray tube was manufactured.

  First, the target structure 101 shown in FIG. 6 was produced, and the produced target structure 101 and the anode 108 were brazed as shown in FIG. Specifically, it is as follows. Using SUMI-CRYSTAL manufactured by Sumitomo Electric Industries, Ltd., which is an artificial diamond having a diameter of 8 mm and a thickness of 2 mm as the substrate 103, the side surface of the substrate 103 was metallized with a Ti-containing paste to form a metallized layer 104. Next, Ti was applied to the entire surface of one side of the substrate 103 by sputtering, and W having a thickness of 10 μm was formed as the target 102. Subsequently, an inorganic conductive adhesive 597A manufactured by Alemco Co., Ltd. was used on the periphery of the substrate 103 to apply between the target 102 and the metallized layer 104 to establish electrical continuity, thereby completing the target structure 101. After that, the target structure 101 is placed inside the Kovar anode 108, the surface on which the target 102 is formed, and the brazing material BA-108 manufactured by Toyo Riken Co., Ltd. is used. The brazing part 105 was formed and vacuum-tightly sealed. At this time, the target structure 101 was protruded from the surroundings, and was installed 1 mm higher than the anode 108. This brazing was performed in the same manner as in Example 1. The brazing material 106 that flowed out was blocked by a step 607 formed by causing the target structure 101 to protrude from the periphery, and the flow toward the target structure 101 side was prevented.

  Next, as in Example 1, the electron gun flange 204 and the insulator 205 on which the electron gun unit 201 and the like were installed were produced. Using the produced electron gun flange 204 and insulator 205 and the anode 108 provided with the target structure 101 produced by the above-described method, brazing was performed in the same manner as in Example 1, and the result is shown in FIG. The envelope 208 was completed. Subsequently, as in Example 1, vacuum baking, aging, chip-off, etc. were performed to complete the X-ray tube 200 shown in FIG. Thereafter, in the same manner as in Example 1, an X-ray generator provided with this X-ray tube was produced.

  When the produced X-ray generator was evaluated by the same method as in Example 1, the amount of characteristic X-rays from Ag and Cu, which are the components of the brazing material 106 that flowed out, was 0.1% or less, which is a problem. It did not become.

[Comparative example]
As a comparative example, an X-ray tube having the same configuration as that of Example 1 except that the barrier 107 was not provided was manufactured, and an X-ray generation apparatus including the X-ray tube was manufactured.

  About the produced X-ray generator, it evaluated by the same method as Example 1. FIG. Regarding characteristic X-rays (Ag: 22.2 keV, 24.9 keV, Cu: 8.0 keV, 8.9 keV) from Ag and Cu, which are components of the brazing material 106 that flowed out, respectively, compared with Examples 1 to 5 It was emitted 50 to 300 times more, and the effect of the present invention was confirmed.

  101: target structure, 102: target, 103: substrate, 104: metallized layer, 105: brazing portion, 106: flowing brazing material, 107: barrier, 108: anode, 109: electron beam, 200: X-ray tube , 201: electron gun unit, 202: cathode, 203: control electrode, 204: electron gun flange, 205: insulator, 208: envelope, 209: getter, 210: voltage / current introduction unit, 211: drive power supply, 212: X-ray circumscribed window, 213: container, 214: insulating oil, 307: groove, 310, 410: conductive member, 507: conductive barrier, 607: step

Claims (13)

A substrate, a target provided on one side of the substrate, an anode bonded to a side surface of the substrate by a brazing material, a cathode disposed opposite to the target, emitting electrons and irradiating the targets with the electrons; ,
An X-ray tube having
An X-ray tube characterized in that at least a part of the peripheral area of the one surface of the substrate is a step for blocking the brazing material that has flowed out.   The X-ray tube according to claim 1, wherein the step is constituted by a convex barrier.   The X-ray tube according to claim 2, wherein the barrier has no affinity for the brazing material.   The X-ray tube according to claim 2, wherein the barrier is made of an inorganic material whose main component is ceramics.   The X-ray tube according to claim 2, wherein the barrier is made of a conductive inorganic material.   The target is provided on the entire surface of the one surface of the substrate, the target and the anode are electrically connected at a peripheral portion of the target, and the barrier is provided on the target. Item 6. The X-ray tube according to any one of Items 2 to 5.   The target is provided in a region excluding the peripheral region of the one side of the substrate, a conductive member is provided in the peripheral region of the one side of the substrate, and the target and the anode are electrically connected via the conductive member. The X-ray tube according to claim 2, wherein the X-ray tube is connected and the barrier is provided on the conductive member.   The target is provided in a region excluding the peripheral region of the one side of the substrate, the barrier is provided in the peripheral region of the one side of the substrate, and the target and the anode are electrically connected via the barrier. The X-ray tube according to claim 5, wherein   The X-ray tube according to claim 1, wherein the step is constituted by a groove along the one surface of the substrate.   The target is provided in a region excluding the peripheral region of the one side of the substrate, a conductive member is provided across the groove in the peripheral region of the one side of the substrate, and the target and the anode are connected to the conductive member. The X-ray tube according to claim 9, wherein the X-ray tube is electrically connected to the X-ray tube.   The X-ray tube according to claim 1, wherein the step is configured by projecting the one surface of the substrate from the periphery.   The X-ray tube according to any one of claims 1 to 11, wherein the substrate is made of ceramic, diamond, or other inorganic material having insulating properties. It is a manufacturing method of the X-ray tube according to any one of claims 1 to 12,
A method for manufacturing an X-ray tube, characterized in that, when the side surface of the substrate and the anode are bonded with a brazing material, the one surface of the substrate is bonded upward.

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