Insulating device for isolating high voltage electrodes in a vacuum environment

Abstract

The application provides an insulation device for isolating high-voltage electrodes in a vacuum environment, comprising: an insulator comprising a first end face and a second end face opposite to each other, the first end face being connected with a first electrode, the second end face being connected with a second electrode, the first electrode and the second electrode being located in the vacuum environment, and the electric potential of the first electrode being less than that of the second electrode; wherein the surface layer of the first end face of the insulator and the surface layer in the vicinity of the side face of the first end face are covered with a conductive layer. The application improves the electric field at the electrode, the insulator and the vacuum contact surface, thereby improving the voltage resistance performance of the insulator in the vacuum environment.

Description

Technical Field

[0001] This invention relates to the field of semiconductors, and more particularly to an insulating device for isolating high-voltage electrodes in a vacuum environment. Background Technology

[0002] Insulation devices are widely used in equipment requiring the isolation of high-voltage electrodes in a vacuum environment, such as charged particle beam devices, X-ray tubes, and particle accelerators. Currently, the structure of insulation devices is as follows: Figure 1 As shown, insulator 120 is used to support metal electrodes 112 and 111 with different potentials. A vacuum environment can improve the withstand voltage performance of insulator 120, and the entire insulator 120 and metal electrodes 112 and 111 are placed in a vacuum environment. Compared to the insulation method of a vacuum gap, when insulator 120 is added with equal distance between metal electrodes 112 and 111, breakdown and discharge will occur between the electrodes at a lower voltage. This phenomenon can be called insulator surface flashover breakdown, and insulator surface flashover severely restricts the performance of insulation devices and metal electrodes in a vacuum environment.

[0003] Specifically, in a vacuum environment, flashover on the surface of insulator 120 is caused by the emission of cathode electrons 112e due to the enhanced electric field at the contact surface (defined as triple junction) of the metal electrode, insulator, and vacuum environment. The excited electrons 112e bombard the surface of insulator 120 and the gas molecules adsorbed on its surface, exciting new secondary electrons 112e. As the electrons 112e continue to move, flashover breakdown eventually occurs.

[0004] refer to Figure 2 and Figure 3 , Figure 2 and Figure 3 The diagrams show the potential distribution of the metal electrode 112, insulator 120, and vacuum contact surface under ideal and micro-defect conditions, respectively. The potential distribution diagrams show that when a micro-defect exists at the contact surface, the potential density at point A (the contact surface between the metal electrode 112, insulator 120, and vacuum) increases, meaning the electric field at point A is strengthened, thereby reducing the flashover breakdown voltage of the insulator 120. In practical applications, a perfect fit between the metal electrode 112 and the insulator 120 is almost impossible. The existence of a gap between the metal electrode 112 and the insulator 120 leads to a decrease in the withstand voltage of the insulator 120, resulting in a decline in the performance of the vacuum electrical device or damage to it.

[0005] Therefore, how to improve the electric field at the electrode, insulator and vacuum contact surface, thereby improving the withstand voltage performance of the insulator in a vacuum environment, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] In order to overcome the defects of the above-mentioned related technologies, the present invention provides an insulating device for isolating high-voltage electrodes in a vacuum environment, which improves the electric field at the electrode, insulator and vacuum contact surface, thereby improving the withstand voltage performance of the insulator in a vacuum environment.

[0007] According to one aspect of the present invention, an insulating device for isolating high-voltage electrodes in a vacuum environment is provided, comprising:

[0008] An insulator includes a first end face and a second end face facing away from each other. The first end face is connected to a first electrode, and the second end face is connected to a second electrode. The first electrode and the second electrode are located in the vacuum environment, and the potential of the first electrode is less than the potential of the second electrode.

[0009] The surface layer of the first end face of the insulator and the adjacent surface layer of the side surface of the first end face are covered with a conductive layer.

[0010] In some embodiments of the present invention, the surface layer of the second end face of the insulator and the surface layer of the side adjacent area of ​​the second end face are covered with a conductive layer.

[0011] In some embodiments of the present invention, the thickness of the conductive layer is less than 1 micrometer.

[0012] In some embodiments of the present invention, the conductive layer includes a metal layer or a semiconductor layer.

[0013] In some embodiments of the present invention, the conductive layer is prepared by at least one of the following processes: physical vapor deposition, physical vapor deposition, chemical vapor deposition, chemical electroplating, and ion implantation.

[0014] In some embodiments of the present invention, the side neighboring surface layer of the first end face forms a rounded corner structure or a chamfered structure.

[0015] In some embodiments of the present invention, the chamfer angle of the chamfer structure is greater than or equal to 5 degrees and less than or equal to 85 degrees.

[0016] In some embodiments of the present invention, the chamfer height of the chamfer structure is greater than or equal to 0.1 mm and less than or equal to 1 mm.

[0017] In some embodiments of the present invention, the insulator is an inorganic material or an organic material.

[0018] In some embodiments of the present invention, the voltage v between the first electrode and the second electrode, and the path length L between the first electrode and the second electrode along the surface of the insulator, satisfy the following mathematical relationship: 0.8 kV / mm <v / L<1.5kV / mm。

[0019] Compared with the prior art, the advantages of this invention are:

[0020] On the one hand, by covering the surface layer of the first end face of the insulator and the surface layer of the adjacent side of the first end face with a conductive layer, an equipotential surface is generated in the insulator when the first electrode contacts it, thereby reducing the electric field strength at the contact surface (the adjacent side of the first end face) of the insulator, the first electrode, and the vacuum environment, and thus improving the breakdown voltage of the insulator in the vacuum environment. On the other hand, since the flashover phenomenon on the surface of the insulator is mainly caused by the electrode with a lower potential, the first end face and its adjacent side of the insulator in contact with the first electrode with a lower potential are prone to insulation failure. Therefore, covering the surface layer of the first end face of the insulator and the surface layer of the adjacent side of the first end face with a conductive layer can effectively improve the insulation performance. Attached Figure Description

[0021] The above and other features and advantages of the present invention will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0022] Figure 1 A schematic diagram of the insulation device is shown.

[0023] Figure 2 The potential distribution diagram of the metal electrode, insulator, and vacuum contact surface under ideal conditions is shown.

[0024] Figure 3 The potential distribution diagrams of the metal electrode, insulator, and vacuum contact surface under micro-defect conditions are shown.

[0025] Figure 4 A schematic diagram of an insulating device according to an embodiment of the present invention is shown.

[0026] Figure 5 A schematic diagram of an insulating device according to another embodiment of the present invention is shown.

[0027] Figure 6 The diagram shows the electric field intensity distribution of the metal electrode, insulator, and vacuum contact surface under ideal conditions.

[0028] Figure 7 The electric field intensity distribution of the metal electrode, insulator, and vacuum contact surface under micro-imperfection conditions is shown.

[0029] Figure 8 The diagram shows the electric field intensity distribution when a rounded corner structure is formed on the side neighbor surface of the first end face of the metal electrode, insulator, and vacuum contact surface according to an embodiment of the present invention.

[0030] Figure 9 The diagram shows the electric field intensity distribution when a chamfered structure is formed on the side neighbor surface of the first end face of the metal electrode, insulator, and vacuum contact surface according to an embodiment of the present invention.

[0031] Figure 10 A schematic diagram of an insulating device having a chamfered structure formed on the side neighboring surface layer of the first end face according to an embodiment of the present invention is shown.

[0032] Figure 11 The diagram shows the electric field intensity distribution when a predetermined chamfer structure is formed on the side neighbor surface layer of the first end face of the metal electrode, insulator, and vacuum contact surface according to an embodiment of the present invention. Detailed Implementation

[0033] Example embodiments will now be described more fully with reference to the accompanying drawings. However, these example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of the specific details described, or other methods, materials, apparatus, etc., can be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring aspects of this disclosure. The same reference numerals in the figures denote the same or similar structures, and therefore their detailed descriptions are omitted.

[0034] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including,” “having,” and “have” are used to indicate an open-ended inclusion meaning and that other elements / components / etc. may exist in addition to the listed elements / components / etc.

[0035] This invention provides an insulating device for isolating high-voltage electrodes in a vacuum environment, which improves the electric field at the electrode, insulator, and vacuum contact surface, thereby enhancing the withstand voltage performance of the insulator in a vacuum environment.

[0036] See below. Figure 4 , Figure 4 A schematic diagram of an insulating device according to an embodiment of the present invention is shown.

[0037] An insulating device for isolating high-voltage electrodes in a vacuum environment includes an insulator 220. The insulator 220 includes a first end face 220A and a second end face 220B facing away from each other. The first end face 220A is connected to a first electrode 211, and the second end face 220B is connected to a second electrode 212. The first electrode 211 and the second electrode 212 are located in the vacuum environment, and the potential of the first electrode 211 is less than the potential of the second electrode 212. A conductive layer 221 covers the surface of the first end face 220A and the surface of its lateral adjacent area 222.

[0038] Specifically, by setting the conductive layer 221, an equipotential surface is generated when the first end face 220A of the insulator 220 comes into contact with the first electrode 211, thereby reducing the electric field strength at the contact surface (the side neighbor 222 of the first end face 220A) of the insulator 220, the first electrode 211 and the vacuum environment, thereby improving the breakdown voltage of the insulator 220 in the vacuum environment.

[0039] Specifically, since the surface flashover phenomenon of the insulator 220 is mainly caused by the electrode with a lower potential, insulation failure is likely to occur at the first end face 220A and its side area 222 of the first electrode 211 with a lower potential. Therefore, a conductive layer 221 is covered on the surface of the first end face 220A and the surface of the side area 222 of the first end face 220A, which can effectively improve the insulation performance.

[0040] In some embodiments, the side neighboring surface layer of the first end face may be formed with a rounded corner structure or a chamfered structure. See also Figure 6-9 , Figure 6 The electric field intensity distribution of the metal electrode, insulator, and vacuum contact surface under ideal conditions is shown. Figure 7 The electric field intensity distribution of the metal electrode, insulator, and vacuum contact surface under micro-defect conditions is shown. Figure 8 The diagram shows the electric field intensity distribution when a rounded corner structure is formed in the side neighbor surface layer of the first end face of the metal electrode, insulator and vacuum contact surface according to an embodiment of the present invention. Figure 9 An electric field intensity distribution diagram is shown when a chamfered structure is formed in the side neighbor surface layer of the first end face of the metal electrode, insulator, and vacuum contact surface according to an embodiment of the present invention. For clarity, in Figures 6 to 9 In the figure, the electric field lines shown are equipotential lines. The electric field strength increases with the direction of the dashed line. The specific electric field strength can be determined by referring to the gray scale of the electric field strength on the right side of each figure.

[0041] Figures 6 to 9In this example, taking alumina ceramic as the insulator with a dielectric constant of 10 and a metal electrode voltage of -10kV as an example, the electric field strength is simulated. The ideal maximum electric field strength at the interface between the insulator 220, the first electrode 211, and the vacuum environment is 1.1e5 V / m (reference). Figure 6 The maximum electric field strength at the contact surface between the insulator 120, the first electrode 111, and the vacuum environment under micro-imperfection conditions is 2.36e6 V / m (reference). Figure 7 The electric field strength at the gap between the insulator 120 and the first electrode 111. The maximum electric field strength at the contact surface between the insulator 220 (with conductive layers 221 and 221'), the first electrode 211, and the vacuum environment is compared to... Figure 7 The maximum electric field strength shown is significantly reduced and approaches 0 (reference). Figure 8 and Figure 9 Specifically, when the side adjacent surface layer of the first end face can form a rounded corner structure, the maximum electric field strength at the contact surface of the insulator 220 with conductive layer 221, the first electrode 211, and the vacuum environment is 4.5e5 V / m (reference). Figure 8 When a chamfered structure can be formed on the side adjacent surface of the first end face, the maximum electric field strength at the contact surface of the insulator 220 with conductive layer 221', the first electrode 211, and the vacuum environment is related to the angle and height of the chamfered structure. Figure 10 The electric field intensity decreases as the height H decreases, gradually approaching the electric field of the ideal model; the magnitude of the maximum electric field intensity at the contact surface decreases with the angle of the chamfered structure (e.g., Figure 10 The decreasing angle α shows a trend of increasing, as illustrated in Tables 1 and 2:

[0042] Table 1: Maximum electric field intensity corresponding to different chamfer heights when the chamfer angle is 45 degrees.

[0043]

[0044]

[0045] Table 2: Maximum electric field intensity corresponding to different chamfer heights when the chamfer height is 1 mm.

[0046] 85° 1.89e5 75° 2.28e5 60° 2.24e5 45° 2.69e5 30° 2.01e5 15° 2.98e5 5° 2.9e5

[0047] Therefore, in some embodiments, the chamfer angle of the chamfer structure can be greater than or equal to 5 degrees and less than or equal to 85 degrees, so that the maximum electric field strength can be close to the ideal state by adjusting the chamfer angle. Preferably, the chamfer angle of the chamfer structure can be 85 degrees. In other embodiments, the chamfer height of the chamfer structure is greater than or equal to 0.1 mm and less than or equal to 1 mm, so that the maximum electric field strength can be close to the ideal state by adjusting the chamfer height. Preferably, the chamfer height of the chamfer structure can be 0.1 mm.

[0048] In a preferred embodiment, the chamfer angle of the chamfer structure is 85 degrees and the chamfer height of the chamfer structure is 0.1 mm, such as... Figure 11 The conductive layer 211” with the chamfered structure shown has a maximum electric field strength of 1.13e5V / m at the metal electrode, insulator and vacuum contact surface, which greatly reduces the maximum electric field strength at the metal electrode, insulator and vacuum contact surface and effectively improves the high voltage resistance performance of the insulator.

[0049] Furthermore, the present invention also provides an insulating device according to another embodiment, see schematic diagram. Figure 5 .

[0050] In this embodiment, in addition to the conductive layer 221, the insulator 220 is also covered with a conductive layer 223 on the surface of the second end face 220B and the surface of the side neighbor 224 of the second end face 220B. Thus, the conductive layer 223 creates an equipotential surface when the second end face 220B of the insulator 220 contacts the second electrode 212, thereby reducing the electric field strength at the contact surface (side neighbor 224 of the second end face 220B) of the insulator 220, the second electrode 212, and the vacuum environment, further improving the breakdown voltage of the insulator 220 in a vacuum environment.

[0051] In some embodiments, the insulator can be an inorganic or organic material. Considering that inorganic materials have better vacuum adaptability, electrical withstand voltage performance, and high-temperature resistance than organic materials, in some embodiments, the insulator can be an inorganic material. Preferably, the insulator can be alumina ceramic, for example, a ceramic with an alumina content greater than 95%, to improve the insulator's withstand voltage and high-temperature resistance. This application is not limited to this; the insulator can also be inorganic materials such as aluminum nitride, silicon nitride, beryllium oxide, and silicon carbide.

[0052] In some embodiments, the thickness of the conductive layer can be less than 1 micrometer to avoid the formation of a discontinuity during the formation of the conductive layer due to excessive thickness. At the same time, by reducing the thickness of the conductive layer, the roughness of the surface of the conductive layer facing the electrode can be significantly reduced, thereby avoiding an increase in the electric field strength at the contact surface of the insulator, the electrode and the vacuum environment due to roughness.

[0053] In some embodiments, the conductive layer can be prepared by at least one of the following processes: physical vapor deposition, physical vapor deposition, chemical vapor deposition, chemical electroplating, and ion implantation. Preferably, ion implantation can be used to prepare the conductive layer so that a conductive layer is formed on the end face of the insulator itself, reducing the surface roughness of the conductive layer facing the electrode. Other methods of preparing the conductive layer are also within the scope of protection of this application.

[0054] In some embodiments, the conductive layer may include a metal layer or a semiconductor layer. The metal layer may be aluminum, copper, cobalt, tungsten, etc. The semiconductor layer may be silicon carbide, doped silicon, etc. By using different materials for the metal layer or semiconductor layer, the electric field at the side surface of the insulator's end face can be adjusted. Many more variations are possible in this application, which will not be elaborated upon here.

[0055] In some embodiments, the withstand voltage between electrodes is related to the vacuum level, the length of the insulator between the electrodes, and the surface roughness of the electrodes.

[0056] With other conditions remaining constant, the lower the vacuum level, the better the withstand voltage performance of the insulator between the electrodes. When the vacuum level is below e-3 Pa, the flashover phenomenon on the insulator surface is independent of the vacuum level change. Therefore, in some embodiments, the vacuum level of the electrodes can be below e-3 Pa, thereby effectively improving the withstand voltage performance of the insulator between the electrodes through the conductive layer. Preferably, the vacuum level of the electrodes can be below e-5 Pa.

[0057] With other conditions remaining constant, the smaller the surface roughness of the electrode contact insulator, the better the withstand voltage performance. The surface roughness of the electrode contact insulator can be less than 0.8 micrometers, and in some preferred embodiments, it can be less than 0.2 micrometers. Therefore, by reducing the surface roughness of the electrode contact insulator, the increase in the electric field strength at the contact surface between the insulator, electrode, and vacuum environment due to roughness can be avoided.

[0058] When other conditions remain unchanged, the longer the path of the insulator between the electrodes (i.e., the shortest path from one electrode through the insulator to the other electrode, which is not the spatial vertical distance between the first electrode and the second electrode. When the sidewall of the insulator has a curved shape, the total length of the surface curved path can be used as the path of the insulator between the electrodes), the better the voltage withstand performance. The voltage v between the first electrode and the second electrode, and the path length L along the surface of the insulator between the first electrode and the second electrode, can satisfy the following mathematical relationship: 0.8 kV / mm < v / L < 1.5 kV / mm. In a preferred example, the voltage v between the first electrode and the second electrode, and the path length L along the surface of the insulator between the first electrode and the second electrode can be 1 kV / mm.

[0059] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the icon to another component, these terms are used in this specification only for convenience, for example, according to the direction of the example described in the drawings. It can be understood that if the device of the icon is flipped so that it is upside down, the component described as "upper" will become the component described as "lower". Other relative terms such as "higher", "lower", "top", "bottom", "left", "right", etc. also have similar meanings. When a structure is "on" another structure, it may mean that a structure is integrally formed on another structure, or that a structure is "directly" disposed on another structure, or that a structure is "indirectly" disposed on another structure through another structure.

[0060] In the description of this specification, the description of reference terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0061] The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. An insulation device for isolating a high voltage electrode in a vacuum environment, characterized in that, include: An insulator includes a first end face and a second end face facing away from each other. The first end face is connected to a first electrode, and the second end face is connected to a second electrode. The first electrode and the second electrode are located in the vacuum environment, and the potential of the first electrode is less than the potential of the second electrode. The surface layer of the first end face of the insulator and the side adjacent surface layer of the first end face are covered with a conductive layer, and the side adjacent surface layer of the first end face forms a rounded corner structure or a chamfered structure.

2. The insulating device as described in claim 1, characterized in that, The surface layer of the second end face of the insulator and the adjacent surface layer of the side surface of the second end face are covered with a conductive layer.

3. The insulating device as described in claim 1 or 2, characterized in that, The thickness of the conductive layer is less than 1 micrometer.

4. The insulating device as described in claim 1 or 2, characterized in that, The conductive layer includes a metal layer or a semiconductor layer.

5. The insulating device as described in claim 1 or 2, characterized in that, The conductive layer is prepared by at least one of the following processes: physical vapor deposition, physical vapor deposition, chemical vapor deposition, chemical electroplating, and ion implantation.

6. The insulating device as claimed in claim 1, characterized in that, The chamfer angle of the chamfered structure is greater than or equal to 5 degrees and less than or equal to 85 degrees.

7. The insulating device as claimed in claim 1, characterized in that, The chamfer height of the chamfer structure is greater than or equal to 0.1 mm and less than or equal to 1 mm.

8. The insulating device as described in claim 1 or 2, characterized in that, The insulator is an inorganic or organic material.

9. The insulating device as described in claim 1 or 2, characterized in that, The voltage v between the first electrode and the second electrode, and the path length L along the surface of the insulator between the first electrode and the second electrode, satisfy the following mathematical relationship: 0.8 kV / mm <v / L<1.5 kV / mm。

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