Vacuum capacitor with adjustable self-resonant frequency

Abstract

This invention discloses a vacuum capacitor with an adjustable self-resonant frequency, comprising a vacuum capacitor body and a connecting end made of conductive material. The connecting end is used for electrical connection with an external circuit and for fixing the vacuum capacitor body. A conductive ring is movably fitted on the connecting end, and the position of the conductive ring along the axis of the vacuum capacitor body is adjustable, so that the conductive ring can be flush with the mounting surface of the connecting end. This invention, by using an adjustable conductive ring movably fitted on the connecting end of the vacuum capacitor, allows adjustment of the effective conductive area of ​​the vacuum capacitor by changing the relative position of the conductive ring and the mounting surface, thereby changing the parasitic inductance parameter and adjusting the self-resonant frequency. This avoids system failures such as structural fatigue of the vacuum capacitor, impedance mismatch in the impedance matching device, and overheating and overload of the equipment caused by the self-resonant frequency being the same as the test frequency or operating frequency.

Description

Technical Field

[0001] This utility model relates to the field of vacuum capacitor technology, and in particular to a vacuum capacitor with an adjustable self-resonant frequency. Background Technology

[0002] Vacuum capacitors, due to their high voltage withstand capability, strong current carrying capacity, low high-frequency loss, and good self-healing properties, are now widely used in high-frequency, high-voltage fields such as broadcasting, medical MRI, semiconductor etching, and plasma cleaning. Their working principle involves forming a capacitor through coupling between electrodes, often combined with a high-frequency inductor to form a resonant circuit, achieving impedance matching and stable transmission of radio frequency power.

[0003] Based on their structure and function, vacuum capacitors can be divided into fixed type and variable type: fixed vacuum capacitors have a fixed electrode structure and capacitance value, and are assembled by welding to form a closed vacuum chamber; variable vacuum capacitors change their capacitance value by adjusting the coupling length between the moving electrode group and the stationary electrode group to adapt to different working conditions.

[0004] However, existing vacuum capacitors have the following technical drawbacks: After assembly, due to the fixed overall structure, volume, and geometry of the conductive parts, the self-resonant frequency (SRF) formed by parasitic inductance and capacitance is typically in the range of 10~1000MHz. When the operating frequency or test frequency of the vacuum capacitor equals its self-resonant frequency, the characteristics and function of the vacuum capacitor undergo fundamental changes, leading to structural fatigue, impedance mismatch in the impedance matching device, a significant decrease in RF power transmission efficiency, and system failures such as overheating and overload.

[0005] In fields such as semiconductor manufacturing where frequency accuracy is extremely critical, the aforementioned problems are particularly prominent. Therefore, there is an urgent need for a vacuum capacitor with an adjustable self-resonant frequency to adapt to frequency requirements under different operating conditions and avoid resonance failures. Utility Model Content

[0006] The problem to be solved by this invention is to provide a vacuum capacitor with an adjustable self-resonant frequency, so as to overcome the defects of existing vacuum capacitors caused by impedance mismatch, structural fatigue and system overheating due to self-resonance.

[0007] The technical solution adopted by this utility model to solve its technical problem is: a vacuum capacitor with adjustable self-resonant frequency, including a vacuum capacitor body, the vacuum capacitor body having a connecting end made of conductive material, the connecting end being used for electrical connection with an external circuit and for fixed installation of the vacuum capacitor body; a conductive ring is movably fitted on the connecting end, and the position of the conductive ring along the axial direction of the vacuum capacitor body is adjustable, so that the conductive ring can be flush with the mounting end face of the connecting end.

[0008] As a further improvement of this utility model, the conductive ring has two position states, namely: In the first position state, the conductive ring is offset relative to the mounting end face toward the center of the vacuum capacitor body; In the second position state, the conductive ring is flush with the mounting end face; When the conductive ring is adjusted, it can be switched between the first position state and the second position state.

[0009] As a further improvement of this utility model, the connecting end is circular, and its outer circumferential surface is provided with an external thread. The inner circumferential surface of the conductive ring is provided with an internal thread that matches the external thread. The conductive ring is threadedly installed on the connecting end, and when the conductive ring is rotated, its position along the axis of the vacuum capacitor body is changed.

[0010] As a further improvement of this utility model, the diameter of the end of the connecting end near the mounting end face is reduced to form a cylindrical part and a stepped surface connected to the cylindrical part. The conductive ring is fitted onto the cylindrical part, and the stepped surface is used to stop and limit the conductive ring.

[0011] As a further improvement of this utility model, the mounting end face is provided with a mounting threaded hole.

[0012] As a further improvement of this utility model, the vacuum capacitor body includes two electrode disks, a first ceramic tube sealed between the two electrode disks, and two electrode ring groups respectively fixed on the end faces of the two electrode disks facing each other and coupled to each other, with both electrode disks serving as the connection end.

[0013] As a further improvement of this utility model, one of the two electrode disks is fitted with the conductive ring, or both of the electrode disks are fitted with the conductive ring.

[0014] As a further improvement of this utility model, the vacuum capacitor body includes a moving electrode group and a stationary electrode group, and the position of the moving electrode group within the vacuum capacitor body is adjustable to change the coupling length between it and the stationary electrode group.

[0015] As a further improvement of this utility model, the vacuum capacitor body further includes a second ceramic tube, a base, and a bellows. The static electrode group includes a static electrode disk. The static electrode disk and the base are respectively sealed and fixedly connected to the two ends of the second ceramic tube. The base and the moving electrode group are sealed and connected through the bellows. The base and the static electrode disk are both set as the connection end.

[0016] As a further improvement of this utility model, the conductive ring is fitted onto the base and / or the static electrode disk.

[0017] The beneficial effects of this utility model are as follows: This utility model provides a vacuum capacitor with an adjustable self-resonant frequency. By adjusting the position of the adjustable conductive ring at the connection end of the vacuum capacitor, the effective conductive area of ​​the vacuum capacitor can be adjusted by changing the relative position of the conductive ring and the mounting end face, thereby changing the parasitic inductance parameters and adjusting the self-resonant frequency. This avoids system failures such as structural fatigue of the vacuum capacitor, impedance mismatch of the impedance matching device, and overheating of the equipment caused by the self-resonant frequency being the same as the test frequency or operating frequency. This meets the needs of vacuum capacitors in the field of semiconductor manufacturing equipment. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a perspective view of a first embodiment of the vacuum capacitor with adjustable self-resonant frequency according to the present invention; Figure 2 This is a cross-sectional view of the conductive ring in the first position state in Embodiment 1 of this utility model; Figure 3 This is a perspective view of the conductive ring in Embodiment 1 of this utility model; Figure 4 This is a cross-sectional view of the conductive ring in the second position state in Embodiment 1 of this utility model; Figure 5 This is a perspective view of a second embodiment of the vacuum capacitor with adjustable self-resonant frequency according to the present invention. Figure 6 This is a cross-sectional view of the conductive ring in the first position state in Embodiment 2 of this utility model; Figure 7 This is a cross-sectional view of the conductive ring in the second position state in Embodiment 2 of this utility model.

[0020] Referring to the accompanying drawings, the following explanations are provided: 1. Vacuum capacitor body; 100. Mounting end face; 101. Mounting threaded hole; 110. Cylindrical part; 120. Stepped surface; 2. Conductive ring; 201. Internal thread; 11. Electrode disk; 12. First ceramic tube; 13. Electrode ring assembly; 14. Second ceramic tube; 15. Base; 16. Bellows; 17. Static electrode disk; 18. Static electrode ring assembly; 19. Moving electrode disk; 20. Moving electrode ring assembly; 21. Pull rod. Detailed Implementation

[0021] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0022] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0024] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0025] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0026] The technical solutions provided by the various embodiments of this application are described below with reference to the accompanying drawings.

[0027] See Figures 1 to 7This utility model provides a vacuum capacitor with an adjustable self-resonant frequency, including a vacuum capacitor body 1. The vacuum capacitor body 1 is provided with a connecting end made of conductive material, which is used for electrical connection with an external circuit and for fixing the vacuum capacitor body 1. The outer end face of the connecting end is designated as the mounting end face 100.

[0028] As one of the important improvements in this application, a conductive ring 2 is movably fitted onto the connection end, and the position of the conductive ring 2 along the axis of the vacuum capacitor body 1 is adjustable. By adjusting the conductive ring 2, it can be made flush with the mounting end face 100 of the connection end, thereby changing the conductive area of ​​the vacuum capacitor (before adjustment, the conductive area of ​​the vacuum capacitor is only the mounting end face 100; after adjustment, the conductive area of ​​the vacuum capacitor is composed of the mounting end face 100 and the end face of the conductive ring 2), thus changing the self-resonant frequency of the vacuum capacitor. The specific reasons are as follows: It is well known that the self-resonant frequency (SRF) of a vacuum capacitor is determined by its capacitance (C) and parasitic inductance (L), and the calculation formula is as follows:

[0029] When the conductive ring 2 is adjusted to change the conductive area of ​​the vacuum capacitor, it is equivalent to changing the effective geometry of the conductive part. The change in conductive area will directly lead to a change in parasitic inductance. Since the self-resonant frequency is determined by the capacitance and parasitic inductance of the vacuum capacitor, when the capacitance (for a fixed vacuum capacitor) or the basic capacitor structure (for a variable vacuum capacitor) remains unchanged, the change in parasitic inductance will directly lead to a change in the self-resonant frequency.

[0030] As can be seen, this application, through the adjustable conductive ring 2 at the connection end of the vacuum capacitor, can adjust the effective conductive area of ​​the vacuum capacitor by changing the relative position of the conductive ring 2 and the mounting end face 100, thereby changing the parasitic inductance parameters and adjusting the self-resonant frequency. This avoids system failures such as structural fatigue of the vacuum capacitor, impedance mismatch of the impedance matching device, and overheating of the equipment caused by the self-resonant frequency being the same as the test frequency or operating frequency, thus meeting the needs of vacuum capacitors in the field of semiconductor manufacturing equipment.

[0031] The conductive ring 2 has two positional states: In the first position state, the conductive ring 2 is biased relative to the mounting end face 100 toward the center of the vacuum capacitor body 1, and the bias distance is not required. In the second position state, the outer end face of the conductive ring 2 is flush with the mounting end face 100; Adjusting the conductive ring 2 allows it to switch between a first position and a second position. In this way, the adjustment of the conductive ring 2 only changes the conductive area of ​​the vacuum capacitor without increasing its overall height. This allows it to be directly adapted to the installation space of existing equipment without requiring modifications to external circuitry or mechanical structures, thus reducing application costs.

[0032] Preferably, the conductive ring 2 is fitted onto the connecting end in a threaded connection manner.

[0033] Specifically, the connecting end is circular, with an external thread on its outer circumference. The inner circumference of the conductive ring 2 has an internal thread 201 that matches the external thread. The conductive ring 2 is threaded onto the connecting end. Rotating the conductive ring 2 changes its position along the axis of the vacuum capacitor body 1. In this application, the conductive ring 2 and the connecting end achieve axial position adjustment through threaded engagement. This has advantages such as convenient operation, easy adjustment, fewer additional parts, and easy assembly. It also ensures that the conductive ring 2 is flush with the mounting end face 100 after adjustment, ensuring reliable contact between the conductive ring 2 and external circuits or mechanical structures.

[0034] Of course, the adjustment of the conductive ring 2 in this application is not limited to the threaded connection. For example, the conductive ring 2 can also be slidably fitted onto the connection end and the two can be locked together radially by screws. In addition, in order to ensure the reliability of the electrical connection between the two, spring contacts or the like can be installed between the two, so that the conductive area of ​​the vacuum capacitor can be changed by adjusting the conductive ring 2, thereby changing the self-resonant frequency of the vacuum capacitor.

[0035] Furthermore, the diameter of the end of the connection near the mounting end face 100 is reduced to form a cylindrical part 110 and a stepped surface 120 perpendicularly connected to the cylindrical part 110. An external thread is provided on the cylindrical part 110, and the conductive ring 2 is threadedly fitted onto the cylindrical part 110. The stepped surface 120 is used to stop and limit the conductive ring 2, which can ensure that the conductive ring 2 does not undergo excessive displacement during adjustment and ensure structural stability.

[0036] In this utility model, the mounting end face 100 of the connecting end is provided with a mounting threaded hole 101. The number of mounting threaded holes is one or more, which are used to electrically connect with external circuits or mechanical structures and realize the fixed installation of the vacuum capacitor body 1.

[0037] The structure of this application can be applied to both fixed vacuum capacitors and variable vacuum capacitors. The specific structures of the two embodiments, fixed vacuum capacitor and variable vacuum capacitor, are described in detail below.

[0038] Example 1

[0039] See Figures 1 to 4In this embodiment, the vacuum capacitor body 1 is a fixed vacuum capacitor, which includes two electrode disks 11, a first ceramic tube 12, and two electrode ring groups 13.

[0040] The first ceramic tube 12 is a cylindrical shape with open ends, typically made of ceramic material. Two circular electrode disks 11 are sealed and fixedly connected to the upper and lower ends of the first ceramic tube 12, respectively, using methods such as, but not limited to, brazing. The first ceramic tube 12 and the two electrode disks 11 cooperate to form a sealed space, which is configured as a vacuum chamber. Two electrode ring assemblies 13 are respectively fixed to the end faces of the two electrode disks 11 facing each other, and the two electrode ring assemblies 13 are coupled together and housed within the vacuum chamber.

[0041] The two electrode ring groups 13 are both composed of multiple electrode rings of different diameters arranged concentrically at intervals. The electrode rings in the two electrode ring groups 13 are alternately and concentrically arranged in the vacuum chamber so that the two electrode ring groups 13 can couple with each other through the electric field formed between them. The coupling length between the two electrode ring groups 13 does not change, and the capacitance of the vacuum capacitor body 1 is a constant value.

[0042] The coupling length mentioned in this article refers to the effective length of the two electrode ring groups 13 that influence and interact with each other under the action of an electric field, that is, the length of the overlap of the two electrode ring groups 13 facing each other in the radial direction.

[0043] Furthermore, in this embodiment, the two connection terminals on the vacuum capacitor body 1 are two electrode disks 11.

[0044] Optionally, either of the two electrode disks 11 may be fitted with a conductive ring 2, or both electrode disks 11 may be fitted with a conductive ring 2, and the conductive ring 2 may be made of the same material as the two electrode disks 11.

[0045] Figure 2 The diagram shows a cross-sectional view of the conductive ring 2 in its first position, where the stop of the conductive ring 2 is located on the stepped surface 120. When the self-resonant frequency of the vacuum capacitor body 1 approaches the test frequency or operating frequency, the conductive ring 2 is rotated to the second position, making it flush with the mounting end face 100 (e.g., ...). Figure 4 As shown in the figure, by changing the conductive area of ​​the vacuum capacitor body 1, the self-resonant frequency of the vacuum capacitor changes accordingly.

[0046] Example 2

[0047] See Figures 5 to 7In this embodiment, the vacuum capacitor body 1 is a variable vacuum capacitor. The vacuum capacitor body 1 includes a moving electrode group and a stationary electrode group. The position of the moving electrode group in the vacuum capacitor body 1 is adjustable to change the coupling length between it and the stationary electrode group, thereby changing the coupling area and realizing capacitance adjustment.

[0048] The static electrode assembly includes a static electrode disk 17 and a static electrode ring assembly 18, which have the same structure as the electrode disk 11 and electrode ring assembly 13 in Embodiment 1, respectively. The static electrode ring assembly 18 is fixed to the end face of the static electrode disk 17 facing the moving electrode disk 19. The moving electrode assembly includes a moving electrode disk 19 and a moving electrode ring assembly 20, which also has the same structure as the electrode ring assembly 13 in Embodiment 1. The moving electrode disk 19 is arranged vertically opposite to the static electrode disk 17, and the moving electrode ring assembly 20 is fixed to the end face of the moving electrode disk 19 facing the static electrode disk 17.

[0049] Furthermore, the vacuum capacitor body 1 also includes a second ceramic tube 14, a base 15, a bellows 16, and a pull rod 21. The second ceramic tube 14 is also a cylindrical shape with open ends. The moving electrode assembly is located inside the second ceramic tube 14. The base 15 and the stationary electrode disk 17 are respectively sealed and fixedly connected to the upper and lower ends of the second ceramic tube 14. The base 15 and the moving electrode disk 19 are sealed and connected through the bellows 16, thereby forming a closed space between the second ceramic tube 14, the base 15, the bellows 16, the moving electrode disk 19, and the stationary electrode disk 17. This closed space is configured as a vacuum chamber, and the moving electrode ring assembly 20 and the stationary electrode ring assembly 18 are coupled and housed in the vacuum chamber.

[0050] Furthermore, the pull rod 21 is located inside the bellows 10, with its lower end fixedly connected to the moving electrode disk 19 and its upper end connected to the transmission mechanism. When an external power device, such as a motor, drives the pull rod 21 to move up and down axially through the transmission mechanism, the pull rod 21 will synchronously drive the moving electrode assembly to move, and at the same time, the bellows 16 will be compressed / stretched accordingly, so that the coupling length between the moving electrode ring assembly 20 and the stationary electrode ring assembly 18 changes, thereby realizing the adjustment of the capacitance value of the vacuum capacitor.

[0051] In this embodiment, the two connection terminals on the vacuum capacitor body 1 are the base 15 and the static electrode disk 17.

[0052] The base 15 and / or the static electrode disk 17 are fitted with a conductive ring 2, and the conductive ring 2 is made of the same material as the base 15 and the static electrode disk 17.

[0053] Figure 6The diagram shown is a cross-sectional view with the conductive ring 2 mounted on the stationary electrode disk 17 in the first position. At this position, the conductive ring 2's stop is located on the stepped surface 120 of the stationary electrode disk 17. When the self-resonant frequency of the vacuum capacitor body 1 approaches the test frequency or operating frequency, the conductive ring 2 is rotated to the second position, making it flush with the mounting end face 100 (e.g., ...). Figure 7 As shown in the figure, by changing the conductive area of ​​the vacuum capacitor body 1, the self-resonant frequency of the vacuum capacitor changes accordingly.

[0054] It is evident that the structure of this utility model can be applied to both fixed vacuum capacitors and variable vacuum capacitors without altering the core structure of the original capacitor, making it easy to promote industrialization.

[0055] The same or similar parts between the various embodiments in this specification can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments.

[0056] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An adjustable self-resonant frequency vacuum capacitor, comprising a vacuum capacitor body (1) provided with a connecting end made of a conductive material, the connecting end being used for electrically connecting with an external circuit and realizing fixed installation of the vacuum capacitor body (1); characterized in that, A conductive ring (2) is movably fitted on the connection end, and the position of the conductive ring (2) along the axis of the vacuum capacitor body (1) is adjustable, so that the conductive ring (2) can be flush with the mounting end face (100) of the connection end.

2. The adjustable self-resonant frequency vacuum capacitor of claim 1, wherein, The conductive ring (2) has two positional states, namely: In the first position state, the conductive ring (2) is biased toward the center of the vacuum capacitor body (1) relative to the mounting end face (100); In the second position state, the conductive ring (2) is flush with the mounting end face (100); When the conductive ring (2) is adjusted, it can be switched between the first position state and the second position state.

3. The adjustable self-resonant frequency vacuum capacitor of claim 1, wherein, The connecting end is circular, and its outer circumference is provided with an external thread. The inner circumference of the conductive ring (2) is provided with an internal thread (201) that matches the external thread. The conductive ring (2) is threadedly installed on the connecting end. When the conductive ring (2) is rotated, its position along the axis of the vacuum capacitor body (1) is changed.

4. The adjustable self-resonant frequency vacuum capacitor of claim 1, wherein, The end of the connection end that is close to the mounting end face (100) has a reduced diameter to form a cylindrical part (110) and a stepped surface (120) connected to the cylindrical part (110). The conductive ring (2) is fitted onto the cylindrical part (110), and the stepped surface (120) is used to stop and limit the conductive ring (2).

5. The adjustable self-resonant frequency vacuum capacitor of claim 1, wherein, The mounting end face (100) is provided with a mounting threaded hole (101).

6. The adjustable self-resonant frequency vacuum capacitor of claim 1, wherein, The vacuum capacitor body (1) includes two electrode disks (11), a first ceramic tube (12) sealed between the two electrode disks (11), and two electrode ring groups (13) fixed on the end faces of the two electrode disks (11) facing each other and coupled to each other. Both electrode disks (11) are set as the connection ends.

7. The adjustable self-resonant frequency vacuum capacitor of claim 6, wherein, One of the two electrode disks (11) is fitted with the conductive ring (2), or both of the electrode disks (11) are fitted with the conductive ring (2).

8. The adjustable self-resonant frequency vacuum capacitor of claim 1, wherein, The vacuum capacitor body (1) includes a moving electrode group and a stationary electrode group, and the position of the moving electrode group within the vacuum capacitor body (1) is adjustable to change the coupling length between it and the stationary electrode group.

9. The adjustable self-resonant frequency vacuum capacitor of claim 8, wherein, The vacuum capacitor body (1) also includes a second ceramic tube (14), a base (15) and a bellows (16). The static electrode group includes a static electrode disk (17). The static electrode disk (17) and the base (15) are respectively sealed and fixedly connected to the two ends of the second ceramic tube (14). The base (15) and the moving electrode group are sealed and connected through the bellows (16). The base (15) and the static electrode disk (17) are both set as the connection end.

10. The adjustable self-resonant frequency vacuum capacitor of claim 9, wherein, The conductive ring (2) is fitted on the base (15) and / or the static electrode disk (17).

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