KR20230109074A - Micro-focus x-ray tube using nano electric field emitter - Google Patents

Abstract

Disclosed is a micro focus X-ray tube.
In detail, the micro-focus X-ray tube has a junction structure in which metal and ceramics are laminated without an exhaust tube by using a nano-field emitter with excellent characteristics.

Description

Micro focus X-ray tube using nano electric field emitter {MICRO-FOCUS X-RAY TUBE USING NANO ELECTRIC FIELD EMITTER}

The present invention relates to a microfocus X-ray tube, and more particularly, to an apparatus and method for a microfocus X-ray tube having a structure in which different materials are bonded.

In general, an X-ray imaging method is a method of precisely inspecting microstructured elements and parts without destroying them. An X-ray imaging method uses X-rays of braking radiation generated when an electron beam focused to a very small size strikes a metal anode target. Here, in order to observe the internal microstructure, an enlarged shadow image of X-rays passing through elements and parts must be obtained. Video magnification process is required.

In other words, in the X-ray imaging method, the shadow image can be enlarged as the distance between the digital X-ray image detector and the X-ray source increases, but this causes a problem in that the amount of X-rays decreases in inverse proportion to the square of the distance. Therefore, in order to obtain an image magnification and an X-ray dose, it is advantageous to place the subject closer to the electron beam focusing point of the X-ray source, that is, the anode target.

However, since the anode target is relatively higher than the cathode electrode from which electron beams are emitted, it is difficult to contact the subject to the anode target due to problems such as insulation because the anode electrode becomes high voltage when the cathode is grounded. Therefore, even if a negative power cathode structure for grounding the anode electrode or a positive power source for the anode is required, a grounded window structure is required at the place where the subject is facing. An X-ray tube having such a structure is shown in FIG. 1 .

In detail, a conventional X-ray tube has a positive power anode and a grounded window structure, and is formed by making a vacuum container by bonding a glass tube and a metal electrode, evacuating internal gas using an exhaust pipe, and then sealing the tube. At this time, the metal head unit is coupled to a metal ring fused to the glass bulb, and each electrode of the electron gun is also connected to the outside through a stem structure fused to glass. Here, when the nano-field emitter is used as an electron source of an electron gun, it is difficult to obtain good quality characteristics when a vacuum X-ray tube is manufactured by using a glass tube insulating exhaust tube method.

The present invention provides a structure of a microfocus X-ray tube having a nano-field emitter realized by stacking a ceramic insulator and a metal electrode.

The present invention provides a structure of a microfocus X-ray tube directly bonded at high temperature through vacuum brazing without an exhaust pipe using a ceramic insulator.

The present invention provides a structure of a microfocus X-ray tube capable of minimizing a distance between a target location where X-rays are generated and a subject by using an electrode and an anode of a window grounded at the head of the microfocus X-ray.

A microfocus X-ray tube according to an embodiment of the present invention includes a head portion made of metal; a ceramic insulating tube bonded to one surface of the head at a high temperature; an electron gun bonded to the side surface of the head unit and equipped with a nano-field emitter; an anode disposed in an inner space formed by the high-temperature bonding of the head and the ceramic insulating tube; and a target in the form of a plate mounted on the anode. can include

The head unit according to an embodiment of the present invention is grounded with a window in the form of a thin plate (sheet), and the window in the form of a sheet emits X-rays generated by the electron beam emitted from the electron gun to the outside of the microfocus X-ray tube. can

In the head part according to an embodiment of the present invention, an insertion tube structure including an intaglio groove is formed on one surface of the head part, and the insertion tube structure is inserted into the ceramic insulation tube and guided by an insulation tube alignment guide to the ceramic section. It can be placed associatively and disjointly.

The head part according to an embodiment of the present invention is bonded to the insulating ceramic of the electron gun through an electron gun bonding ring, and the electron gun may be aligned in position by an electron gun guide formed on a side surface of the head part.

The ceramic insulator tube according to the embodiment of the present invention is bonded to the anode through an anode connection ring, and the position of the ceramic insulator tube can be aligned by an insulator tube guide formed in the anode connection ring.

An electron gun according to an embodiment of the present invention includes a cathode electrode coupled to a cathode plate on which the nano-field emitter is formed; a gate electrode to which a gate plate is coupled; and a focus electrode to which a focus plate is coupled. can include

The gate plate according to an embodiment of the present invention has a gate opening for withdrawing electrons from the nano-field emitter, and the focus plate has a micro-focus opening for accelerating the electrons and focusing the emitted electron beam. X-ray tube.

The target according to the embodiment of the present invention is bonded to the anode by a vacuum brazing filler, and the anode may have an intaglio groove formed so that the bonding area is smaller than that of the target.

A microfocus X-ray tube according to another embodiment of the present invention includes a head portion bonded to an electron gun equipped with a nanofield emitter; a ceramic insulating tube bonded to the head at a high temperature; and an anode bonded to the ceramic insulating tube and equipped with a target in the form of a plate.

The head unit according to an embodiment of the present invention, a window for emitting the electron beam emitted from the electron gun to the outside; a diffusion prevention groove for minimizing brazing pillars in the process of grounding the head and the window; and a ring cover disposed along the anti-diffusion groove. can include

The head part according to an embodiment of the present invention may be formed in an insertion tube structure in which a partial region of the head part is inserted into the ceramic insulating tube.

The head part according to an embodiment of the present invention is bonded to the insulating ceramic of the electron gun through the electron gun bonding ring to the side of the head part, and the position of the electron gun can be aligned by the electron gun guide formed on the side of the head part.

The ceramic insulator tube according to the embodiment of the present invention is bonded to the anode through an anode connection ring, and the position of the ceramic insulator tube can be aligned by an insulator tube guide formed in the anode connection ring.

An electron gun according to an embodiment of the present invention includes a cathode electrode coupled to a cathode plate on which the nano-field emitter is formed; a gate electrode to which a gate plate is coupled; and a focus electrode to which a focus plate is coupled. can include

The gate plate according to an embodiment of the present invention may have a gate opening for withdrawing electrons from the nano-field emitter, and the focus plate may have a focus opening for focusing electron beams emitted by accelerating the electrons. .

In the anode according to an embodiment of the present invention, the target may be mounted by an intaglio groove formed such that a joint area is narrower than that of the target.

According to one embodiment of the present invention, the microfocus X-ray tube may have a nano-field emitter realized by stacking a ceramic insulator and a metal electrode.

According to one embodiment of the present invention, the microfocus X-ray tube can be directly bonded at high temperature through vacuum brazing using a ceramic insulator without an exhaust tube.

According to an embodiment of the present invention, the microfocus X-ray tube can minimize the distance between the position of the target where X-rays are generated and the subject by using the anode and the electrode of the window grounded to the head of the microfocus X-ray.

1 is a diagram illustrating a microfocus X-ray tube according to an exemplary embodiment.
2 is a diagram illustrating a junction structure of a microfocus X-ray tube according to an embodiment.
3 is a view showing a head unit and an electron gun according to an embodiment.
4 is a view showing an anode, a ceramic insulating tube, and an anode connecting ring according to an embodiment.
5 is a diagram showing a detailed configuration of an electron gun according to an embodiment.
6 is a diagram illustrating an anode and a target according to an embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a diagram illustrating a microfocus X-ray tube according to an exemplary embodiment.

Referring to FIG. 2 , the microfocus X-ray tube 100 may include an anode 150, a head part 160, and a ceramic insulating tube 180.

Self-restraint, the head portion 160 is made of a metal material, and one surface of the head portion 160 may be bonded to the window 161 in the form of a sheet. In one example, the sheet form may be a thin plate. Here, the head portion 160 may be bonded together with the ring-shaped seat cover 162 in order to increase the brazing bonding yield of the head portion 160 with the window 161 . The head part 160 may be bonded to the electron gun 110 equipped with the nano field emitter 123 on the side of the head part 160 . Here, the window 161 may serve to emit X-rays 200 generated by the electron beam 111 emitted from the electron gun 110 to the outside of the microfocus X-ray tube 100 .

The head portion 160 may be bonded to the other surface of the head portion 160 with a ceramic insulation tube 180 at high temperature. The ceramic insulation tube 180 may be bonded to the anode 150 through the anode connection ring 152 . Positions of the ceramic insulating tubes 180 forming the microfocus X-ray tube 100 may be aligned by an insulating tube guide formed on the anode connection ring 152 . The inner diameter of the ceramic insulating tube 180 and the outer diameter of the anode connecting ring 152 may be spaced apart in consideration of a thermal expansion coefficient difference, processing error, and the like, and the spaced distance may be 0.2 mm or less based on a radius. Here, the anode 150 may be disposed in the center of an internal space formed by the hot-bonded head portion 160 and the ceramic insulating tube 180 .

The anode 150 may be implemented in a bottleneck structure in which the width of the anode 150 narrows based on a certain point to secure withstand voltage. The anode 150 may be spaced apart from the ceramic insulating tube 180 in the inner space at regular intervals. A plate-shaped target 151 may be disposed on the head of the anode 150 . The head of the anode 150 may be formed to be inclined at a specific angle. The target 151 may be brazed and disposed according to a specific angle of the head of the anode 150 .

In addition, the electron beam 111 emitted from the electron gun 110 is accelerated by the voltage applied to the anode 150, and the X-rays 200 generated from the electron beam 111 reaching the target 151 are It can be emitted to the outside of the microfocus X-ray tube 100 through the window 161 of 160.

2 is a diagram illustrating a junction structure of a microfocus X-ray tube according to an embodiment.

Referring to FIG. 2 , the microfocus X-ray tube 100 does not have a separate exhaust pipe for vacuum exhaust, and may be manufactured as a vacuum sealed tube when brazing each part in a vacuum atmosphere. In addition, in order to minimize stress due to a difference in coefficient of thermal expansion between the ceramic insulating tube 180 and the head portion 160 made of metal, each junction may have a characteristic junction structure.

In detail, the microfocus X-ray tube 100 may have a structure in which a ceramic material of the ceramic insulating tube 180 and a metal material of the head part 160 are bonded at a high temperature. The microfocus X-ray tube 100 may have a structure in which a large diameter is formed on the side of the head part 160 and the electron gun 120 is bonded through the large diameter formed on the side.

In addition, in the micro-focus X-ray tube 100, a high-voltage anode anode is disposed inside the micro-focus X-ray tube 100, and a ground cathode cathode 120 and a window 161 are disposed on the side and upper surfaces of the head portion 160, respectively. ) may have a structure in which is disposed. In the case of bipolar power supply, a positive voltage may be applied to the anode, and a negative voltage may be applied to the window 161 and the cathode.

Therefore, the present invention can provide a more improved microfocus X-ray tube 100 by using a method of directly vacuum brazing without an exhaust pipe with a ceramic insulation structure in order to manufacture a nano-field emitter-based X-ray tube with excellent characteristics.

3 is a view showing a head unit and an electron gun according to an embodiment.

Referring to FIG. 3 , the head unit 160 may have an electron gun 110 having a nano-field emitter disposed on a side surface of the head unit 160 . The electron gun bonding ring 169 of the head part 160 may be bonded to the focus insulating ceramic 141 of the electron gun 110 by brazing. The electron gun 110 may be aligned with the head part 160 by the electron gun alignment guide 170 formed in the head part 160 . The electron gun 110 may include a cathode electrode 120 connected to an external power supply (not shown), a gate electrode 130, and a focus electrode 140. In addition, the cathode electrode 120, the gate electrode 130, and the focus electrode 140 may be insulated and bonded by the insulating ceramic tubes 121, 131, and 141, respectively. The electron gun 110 will be described in more detail with reference to FIG. 5 .

In the head unit 160 , a window 161 may be grounded on one surface of the head unit 160 . The head portion 160 may further include a diffusion prevention groove 166 and a ring cover 162 in relation to the window 161 . The window 161 may emit electron beams emitted from the electron gun 110 to the outside. For example, the window 161 may be formed of beryllium or a thin metal having a thickness of 50 μm or less, for example, copper.

The head portion 160 may be formed with a diffusion prevention groove 166 to minimize brazing filler in a process in which the head portion 160 and the window 161 are grounded. The anti-diffusion groove 166 is concave in the head portion 160 and can be fanned out in a ring shape. The anti-diffusion groove 166 may be formed in the head portion 160 with at least one different diameter. The ring cover 162 may be disposed on the head portion 160 along the anti-diffusion groove 166 .

The anti-diffusion groove 166 and the ring cover 162 may increase the bonding yield by adjusting the degree of diffusion of the brazing filler on the bonding surface.

When the head portion 160 is bonded to the ceramic insulation tube 180, it may be brazed to the insulation tube bonding ring 167 formed on the head portion 160. In the head part 160 , the head part 160 and the ceramic insulator tube 180 may be aligned by an insulator tube alignment guide 168 . The head portion 160 may have an insertion tube structure 164 including an intaglio groove 163 formed therein. The inner diameter of the ceramic insulating tube 180 and the outer diameter of the head portion 160 may be spaced apart in consideration of a thermal expansion coefficient difference, a processing error, and the like, and the distance may be 0.2 mm or less based on a radius.

In addition, the thickness and length forming the electron gun bonding ring 169 of the head portion 160 and the insulator tube bonding ring 167 of the head portion 160 to which different materials are bonded according to the present invention are 0.5 mm and 1.5 mm, respectively. can be

The insertion tube structure 164 may be inserted into the ceramic insulation tube 180 and spaced apart from the ceramic insulation tube 180 by the intaglio groove 163 . For example, the insertion tube structure 164 may be formed with an engraved groove 163 into which a strip-shaped non-volatile getter (not shown) may be mounted.

A separation space 165 may be formed between the head portion 160 and the ceramic insulating tube 180 by the intaglio groove 163 . For example, the head portion 160 has an insertion tube structure 164 inserted into the ceramic insulator tube 180, and is spaced apart from the ceramic insulator tube 180 by the insulator tube alignment guide 168. (165) can be formed.

4 is a view showing an anode, a ceramic insulating tube, and an anode connecting ring according to an embodiment.

Referring to FIG. 4 , a junction structure between the anode 150 , the ceramic insulating tube 180 and the anode connection ring 152 may be shown. In detail, the anode 150 may be made of a material such as copper having good thermal conductivity. The anode 150 may use an anode connecting ring 152 made of a material such as Kovar to overcome the difference in thermal expansion coefficient.

Each joint between the anode 150 and the ceramic insulator 180 utilizes an anode connecting ring 152 having thin junction ring structures 153, 156, and 157, thereby reducing the difference in thermal expansion coefficient. stress can be minimized.

The anode 150 and the anode connecting ring 152 may be brazed at the junction 155, and the ceramic insulator 180 is joined by the bonding ring structure 153 of the anode connecting ring 152. Position alignment is achieved by the insulated tube guide 154.

5 is a diagram showing a detailed configuration of an electron gun according to an embodiment.

Referring to FIG. 5 , the electron gun 110 may include a cathode plate 121 on which nano-field emitters 123 are formed, a gate plate 132 and a focus plate 142 . Here, a cathode electrode may be coupled to the cathode plate 121 , a gate electrode 130 may be coupled to the gate plate 132 , and a focus electrode may be coupled to the focus plate 142 .

In addition, a gate opening 133 may be formed in the gate plate 132 to withdraw electrons from the nano field emitter 123 . A focus opening 143 may be formed in the focus plate 142 to focus the electron beam 111 emitted by accelerating electrons.

The cathode plate 121, the gate plate 132, and the focus plate 142 are electrically connected and bonded to the cathode electrode 120, the gate electrode 130, and the focus electrode 140, respectively, and the cathode electrode 120, the gate The electrode 130, the focus electrode 140, and the head portion 160 may be insulated and bonded by the insulating ceramic tubes 121, 131, and 141, respectively.

Each of the three electrodes may be connected to an external power supply. The distance between the cathode plate 121, the gate plate 132, the focus plate 142 and the head part 160 together with the size of the nano field emitter 123 and the gate opening 133, the focus opening 143 and the head The size of the sub-aperture 171 may be optimized for optimal focusing of the electron beam 111 .

6 is a diagram illustrating an anode and a target according to an embodiment.

Referring to FIG. 6 , the anode 150 and the plate-shaped target 151 may be bonded in various ways. At this time, when the anode 150 is joined using a brazing filler, the concave groove 153 may be formed so that the bonding area is smaller than the area of the target in order to prevent overflow of the filler.

Meanwhile, the method according to the present invention is written as a program that can be executed on a computer and can be implemented in various recording media such as magnetic storage media, optical reading media, and digital storage media.

Implementations of the various techniques described herein may be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or combinations thereof. Implementations may be a computer program product, i.e., an information carrier, e.g., a machine-readable storage, for processing by, or for controlling, the operation of a data processing apparatus, e.g., a programmable processor, computer, or plurality of computers. It can be implemented as a computer program tangibly embodied in a device (computer readable medium) or a radio signal. A computer program, such as the computer program(s) described above, may be written in any form of programming language, including compiled or interpreted languages, and may be written as a stand-alone program or in a module, component, subroutine, or computing environment. It can be deployed in any form, including as other units suitable for the use of. A computer program can be deployed to be processed on one computer or multiple computers at one site or distributed across multiple sites and interconnected by a communication network.

Processors suitable for processing a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from read only memory or random access memory or both. Elements of a computer may include at least one processor that executes instructions and one or more memory devices that store instructions and data. In general, a computer may include, receive data from, send data to, or both, one or more mass storage devices that store data, such as magnetic, magneto-optical disks, or optical disks. It can also be combined to become. Information carriers suitable for embodying computer program instructions and data include, for example, semiconductor memory devices, for example, magnetic media such as hard disks, floppy disks and magnetic tapes, compact disk read only memory (CD-ROM) ), optical media such as DVD (Digital Video Disk), magneto-optical media such as floptical disks, ROM (Read Only Memory), RAM (RAM) , Random Access Memory), flash memory, EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), and the like. The processor and memory may be supplemented by, or included in, special purpose logic circuitry.

In addition, computer readable media may be any available media that can be accessed by a computer, and may include both computer storage media and transmission media.

Although this specification contains many specific implementation details, they should not be construed as limiting on the scope of any invention or what is claimed, but rather as a description of features that may be unique to a particular embodiment of a particular invention. It should be understood. Certain features that are described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable subcombination. Further, while features may operate in particular combinations and are initially depicted as such claimed, one or more features from a claimed combination may in some cases be excluded from that combination, and the claimed combination is a subcombination. or sub-combination variations.

Similarly, while actions are depicted in the drawings in a particular order, it should not be construed as requiring that those actions be performed in the specific order shown or in the sequential order, or that all depicted actions must be performed to obtain desired results. In certain cases, multitasking and parallel processing can be advantageous. Further, the separation of various device components in the embodiments described above should not be understood as requiring such separation in all embodiments, and the program components and devices described may generally be integrated together into a single software product or packaged into multiple software products. You have to understand that you can.

On the other hand, the embodiments of the present invention disclosed in this specification and drawings are only presented as specific examples to aid understanding, and are not intended to limit the scope of the present invention. In addition to the embodiments disclosed herein, it is obvious to those skilled in the art that other modified examples based on the technical idea of the present invention can be implemented.

100: micro focus X-ray tube 110: electron gun
111: electron beam 120: cathode
130: gate 140: focus
150: anode 151: target
152: anode connection ring 160: head part
161: window 162: ring cover
163: intaglio groove 164: insertion tube
180: ceramic insulator 200: X-ray

Claims (16)

In the microfocus X-ray tube,
A head portion made of metal;
a ceramic insulating tube bonded to one surface of the head at a high temperature;
an electron gun bonded to the side surface of the head unit and equipped with a nano-field emitter;
an anode disposed in an inner space formed by the high-temperature bonding of the head and the ceramic insulating tube; and
a plate-shaped target mounted on the anode;
A microfocus X-ray tube comprising a. According to claim 1,
the head part,
It is grounded with a sheet-shaped window,
The window in the form of a sheet,
A micro-focus X-ray tube for emitting X-rays generated by the electron beam emitted from the electron gun to the outside of the micro-focus X-ray tube. According to claim 1,
the head part,
It is formed in an insertion tube structure including an intaglio groove on one side of the head,
The insertion tube structure,
A microfocus X-ray tube inserted into the ceramic insulation tube and spaced apart from the ceramic insulation tube by an insulation tube alignment guide. According to claim 1,
the head part,
Bonded to the insulating ceramic of the electron gun through the electron gun bonding ring,
The electron gun,
A microfocus X-ray tube in which the position of the electron gun is aligned by an electron gun guide formed on a side surface of the head unit. According to claim 1,
The ceramic insulator,
It is bonded to the anode through the anode connecting ring,
A microfocus X-ray tube in which positions of the ceramic insulator tube are aligned by an insulator tube guide formed on the anode connection ring. According to claim 1,
The electron gun,
a cathode electrode coupled to the cathode plate on which the nano-field emitter is formed;
a gate electrode to which a gate plate is coupled; and
Focus electrode combined with focus plate
A microfocus X-ray tube comprising a. According to claim 6,
The gate plate,
A gate opening for withdrawing electrons from the nano-field emitter is formed;
The focus plate,
A microfocus X-ray tube having a focus aperture for concentrating the electron beam emitted by accelerating the electrons. According to claim 1,
The target,
Bonded with the anode by vacuum brazing filler,
The anode,
A microfocus X-ray tube in which an intaglio groove is formed so that a junction area is narrower than the area of the target. In the microfocus X-ray tube,
a head portion bonded to an electron gun equipped with a nano-field emitter;
a ceramic insulating tube bonded to the head at a high temperature; and
an anode bonded to the ceramic insulator tube and equipped with a plate-shaped target;
A microfocus X-ray tube comprising a. According to claim 9,
the head part,
a window for radiating the electron beam emitted from the electron gun to the outside;
a diffusion prevention groove for minimizing brazing pillars in the process of grounding the head and the window; and
A ring cover disposed along the anti-diffusion groove
A microfocus X-ray tube comprising a. According to claim 9,
the head part,
A microfocus X-ray tube formed of an insertion tube structure in which a partial region of the head portion is inserted into the ceramic insulating tube. According to claim 9,
the head part,
It is bonded to the insulating ceramic of the electron gun through the electron gun bonding ring to the side of the head,
A microfocus X-ray tube in which the position of the electron gun is aligned by an electron gun guide formed on a side surface of the head unit. According to claim 9,
The ceramic insulator,
It is bonded to the anode through the anode connecting ring,
A microfocus X-ray tube in which positions of the ceramic insulator tube are aligned by an insulator tube guide formed on the anode connection ring. According to claim 9,
The electron gun,
a cathode electrode coupled to the cathode plate on which the nano-field emitter is formed;
a gate electrode to which a gate plate is coupled; and
Focus electrode combined with focus plate
A microfocus X-ray tube comprising a. According to claim 14,
The gate plate,
A gate opening for withdrawing electrons from the nano-field emitter is formed;
The focus plate,
A microfocus X-ray tube having a focus aperture for concentrating the electron beam emitted by accelerating the electrons. According to claim 9,
The anode,
A microfocus X-ray tube in which the target is mounted by an intaglio groove formed to have a bonding area smaller than that of the target.