Bonding microwave window

Abstract

The utility model relates to microwave window technical field discloses a kind of bonding microwave windows. Including oxygen-free copper ring, further include AIN sheet and boron nitride sheet set on oxygen-free copper ring, AIN sheet and boron nitride sheet concentrically set on oxygen-free copper ring, and boron nitride sheet is located oxygen-free copper ring side close to arc cavity, AIN sheet is connected with oxygen-free copper ring by bonding heat-conducting silica gel. By optimizing vacuum brazing process to bonding with heat-conducting silica gel, manufacturing cost is reduced without affecting product function, and meanwhile, maintenance in later period also only needs to shovel silica gel, effectively improve the AIN sheet replacement efficiency;Meanwhile, by installing boron nitride sheet on the side of microwave window contacting plasma, effectively reduce the pollution or ablation risk caused by AIN sheet directly exposed to plasma environment, can effectively increase the service life of microwave window. Solve the problem that traditional microwave window AIN sheet is easily damaged and process is complex, significantly improve the reliability and maintenance convenience of ion source.

Description

Technical Field

[0001] This utility model belongs to the field of microwave window technology, specifically, it relates to an adhesive microwave window. Background Technology

[0002] The microwave window of a 45GHz ECR ion source, located between the waveguide and the arc cavity, is a key component responsible for vacuum sealing and impedance matching. Its materials typically include quartz, Al₂O₃, and aluminum nitride (AlN). Damage to the microwave window is a major cause of limited ECR ion source lifespan under strong DC beam operation.

[0003] Current microwave windows are made by vacuum brazing an AlN (AlN) sheet with an oxygen-free copper ring and ceramic. This requires expensive brazing furnace equipment, resulting in high welding costs. Furthermore, this manufacturing process encounters several problems during operation: First, during beam extraction, the AlN sheet can become contaminated or ablated under prolonged bombardment by returning electrons, leading to difficulty or failure in arc ignition at the ion source. In this case, the AlN sheet needs to be replaced, requiring the microwave window to be returned to the brazing furnace to melt the weld, clean the solder, and install a new AlN sheet for welding. This entire process is cumbersome and extremely time-consuming and costly. Second, the bombardment by returning electrons raises the temperature of the AlN sheet, creating stress at its edges. Because the solder, copper ring, and ceramic are relatively rigid and do not easily deform, the stress-induced deformation of the AlN sheet can cause it to crack due to compression with the copper ring and ceramic, resulting in loss of its sealing function and microwave window failure. Therefore, solving the problems of cumbersome microwave window manufacturing processes and the susceptibility of AIN wafers to contamination and damage is key to designing and manufacturing new microwave windows. It plays a vital role in reducing the manufacturing and maintenance costs of ion sources and ensuring their long-term stable operation.

[0004] Based on this, the present invention proposes an adhesive microwave window to solve the problems existing in the prior art. Utility Model Content

[0005] In view of this, the main purpose of this utility model is to provide an adhesive microwave window to solve the problems of easy damage to the AIN sheet and complex process of traditional microwave windows.

[0006] To achieve the above objectives, the technical solution of this utility model is implemented as follows: An adhesive microwave window includes an oxygen-free copper ring, and an AlN sheet and a boron nitride sheet disposed on the oxygen-free copper ring. The AlN sheet and the boron nitride sheet are concentrically disposed on the oxygen-free copper ring, and the boron nitride sheet is located on the side of the oxygen-free copper ring closer to the arc cavity, directly exposed to the arc cavity environment. The AlN sheet is connected to the oxygen-free copper ring by adhesive thermally conductive silicone.

[0007] In a preferred embodiment, a central through hole is provided in the middle of the oxygen-free copper ring. The central through hole is designed as a trapezoidal hole structure with a larger inner diameter and a smaller outer diameter. An insert hole and a positioning hole are respectively provided in the central through hole. The insert hole matches the AIN sheet, and the positioning hole matches the boron nitride sheet.

[0008] In a preferred embodiment, the central through hole is connected to both the recessed hole and the positioning hole.

[0009] In a preferred embodiment, the embedded hole is located on the side of the central through hole near the waveguide, and the positioning hole is located on the side of the central through hole near the arc cavity.

[0010] In a preferred embodiment, the embedded hole and the AIN sheet, and the positioning hole and the boron nitride sheet are all concentrically arranged.

[0011] In a preferred embodiment, the surface of the oxygen-free copper ring is provided with a plurality of connecting holes, which are evenly distributed.

[0012] In a preferred embodiment, the edge of the oxygen-free copper ring is further provided with several clearance notches.

[0013] In a preferred embodiment, mounting grooves are provided on both sides of the outer circumference of the oxygen-free copper ring, and a seal is provided in the mounting groove.

[0014] In a preferred embodiment, the seal is an annular rubber sealing ring that matches the mounting groove, and the cross-sectional shape of the sealing ring matches the trapezoidal structure of the mounting groove.

[0015] In a preferred embodiment, the mounting groove is a trapezoidal groove with a large interior and a small opening.

[0016] Compared with the prior art, the present invention provides an adhesive microwave window, which has the following advantages: 1. By optimizing the original complex vacuum brazing process for microwave windows to bonding with thermally conductive silicone, manufacturing costs are reduced without affecting product functionality. Furthermore, subsequent maintenance only requires removing the silicone and replacing it with a new AIN sheet, effectively improving AIN sheet replacement efficiency. Additionally, because silicone can produce significant elastic deformation, the risk of AIN sheet cracking due to stress deformation caused by heat is reduced.

[0017] 2. By adding a boron nitride sheet to the side of the microwave window that comes into contact with the plasma, it can withstand the bombardment of backflow electrons and plasma ablation, effectively reducing the risk of contamination or ablation of the AIN sheet due to direct exposure to the plasma environment, and effectively increasing the service life of the microwave window.

[0018] 3. The trapezoidal mounting grooves on both sides of the outer circle of the oxygen-free copper ring cooperate with the annular rubber sealing ring, and the elastic deformation of the sealing ring fills the tiny gaps in the contact surface to form a stable vacuum seal. At the same time, the oxygen-free copper ring, as the main structure, ensures the concentricity and sealing performance of the AIN sheet and the boron nitride sheet through the precise fit of the embedded hole and the positioning hole.

[0019] 4. The AlN sheet, as the main functional component of the microwave window, achieves impedance matching between the waveguide and the arc cavity through its material properties (low dielectric loss and high thermal conductivity), ensuring efficient transmission of microwave energy to the arc cavity and maintaining stable plasma excitation. This solves the problems of easy damage and complex manufacturing processes associated with traditional microwave window AlN sheets, significantly improving the reliability and ease of maintenance of the ion source. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a front view of the adhesive microwave window of this utility model; Figure 2 This is a schematic diagram of the structure of the adhesive microwave window of this utility model; Figure 3 This utility model Figure 1 Sectional view at point AA; Figure 4 This utility model Figure 3 Enlarged view of a section at point A Figure 5 This is a schematic diagram of the structure of the oxygen-free copper ring of this utility model; Figure 6 This is a schematic diagram of the structure of the boron nitride sheet of this utility model; Figure 7 This is a schematic diagram of the structure of the AIN chip of this utility model.

[0022] [Explanation of Key Component Symbols] 1. Oxygen-free copper ring; 2. AIN sheet; 3. Boron nitride sheet; 4. Adhesive thermal conductive silicone; 5. Embedded hole; 6. Positioning hole; 7. Connection hole; 8. Leaving notch; 9. Seal; 10. Mounting groove. Detailed Implementation

[0023] The structure of the adhesive microwave window will be further described in detail below with reference to the accompanying drawings and embodiments of the present invention.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments as described in this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0028] As per the instruction manual Figures 1-7 As shown, this utility model provides a technical solution: An adhesive microwave window, positioned between a waveguide and an arc cavity, serves to provide vacuum sealing and impedance matching. It includes an oxygen-free copper ring 1, and an AIN sheet 2 and a boron nitride sheet 3 mounted on the oxygen-free copper ring 1. The oxygen-free copper ring 1 acts as the main structure, fixing the AIN sheet 2 and the boron nitride sheet 3. The AIN sheet 2 and the boron nitride sheet 3 are concentrically positioned on the oxygen-free copper ring 1, with the boron nitride sheet 3 located on the side of the oxygen-free copper ring 1 closest to the arc cavity, directly exposed to the arc cavity environment. The AIN sheet 2 is connected to the oxygen-free copper ring 1 by adhesive thermally conductive silicone 4 (such as Dow Corning SE4486).

[0029] In this embodiment, during ECR ion source operation, microwaves are transmitted through a waveguide to the arc cavity to excite plasma, generating high-energy electrons. Some electrons, after acceleration or reflection, move from the arc cavity side towards the microwave window and directly bombard the surface of the boron nitride sheet 3 near the arc cavity. By withstanding the bombardment of the returning electrons and plasma ablation, the boron nitride sheet 3 effectively protects the inner AIN sheet 2 from direct damage. At the same time, when the AIN sheet 2 undergoes stress deformation due to heat, the adhesive thermally conductive silicone 4, with its elastic deformation capability, can alleviate the edge stress concentration caused by the difference in thermal expansion coefficients, reducing the risk of AIN sheet 2 cracking due to compression. This solves the problem of easy contamination and damage to the AIN sheet in the microwave window of traditional brazing processes.

[0030] In a preferred embodiment, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, the oxygen-free copper ring 1 serves as the main structure for bonding the microwave window. A central through-hole is provided in the center of the oxygen-free copper ring 1. The central through-hole is designed as a trapezoidal hole with a larger inner diameter and a smaller outer diameter, facilitating its mating with internal nested components. Furthermore, an embedding hole 5 and a positioning hole 6 are respectively provided inside the central through-hole. The embedding hole 5 is used in conjunction with the AIN sheet 2, and the positioning hole 6 is used in conjunction with the boron nitride sheet 3. Both are directly connected to the central through-hole, together forming the functional layer fixing structure of the microwave window.

[0031] Specifically, the embedded hole 5 is located on the side of the central through hole near the waveguide, and radially limits the AIN chip 2 through size matching, ensuring that the AIN chip 2 is stably installed in the middle of the oxygen-free copper ring 1; the positioning hole 6 is located on the side of the central through hole near the arc cavity, and fixes the boron nitride chip 3 through concentric positioning, so that the boron nitride chip 3 is directly exposed to the arc cavity environment. This design, through the division of labor between the embedded hole 5 and the positioning hole 6, not only ensures the sealing and impedance matching functions of the AIN chip 2, but also utilizes the boron nitride chip 3 to withstand the backflow electron bombardment and plasma ablation, reducing the risk of direct damage to the AIN chip 2.

[0032] In a preferred embodiment, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the oxygen-free copper ring 1 has a disc structure and several connecting holes 7 are provided on its surface. These connecting holes 7 are evenly distributed and are used to achieve precise fixing and installation of the oxygen-free copper ring 1 by cooperating with external bolts or positioning pins in the connecting holes 7 during use, thereby ensuring the stability of the overall structure of the microwave window.

[0033] In a preferred embodiment, such as Figure 1 , Figure 2 , Figure 3 and Figure 5 As shown, the edge of the oxygen-free copper ring 1 is also provided with several clearance notches 8. These clearance notches 8 are formed by partially removing the edge material of the oxygen-free copper ring 1, which simplifies the installation process by utilizing its clearance characteristics; at the same time, after installation, the clearance notches 8 can cooperate with the protruding structures of other components (such as waveguides or arc cavity flanges) to form mechanical limits, effectively preventing the oxygen-free copper ring 1 from rotating during operation, and further improving the reliability of the structure.

[0034] In a preferred embodiment, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, mounting grooves 10 are provided on both sides of the outer circumference of the oxygen-free copper ring 1, and a seal 9 is installed in the mounting groove 10. The seal 9 is fixed to both sides of the oxygen-free copper ring 1 by being embedded in the mounting groove 10, ensuring that it is in close contact with the contact surface of adjacent components (such as waveguides or arc cavity flanges) during use, thus providing a basic guarantee for the vacuum sealing of the microwave window.

[0035] In this embodiment, during use, the seal 9 utilizes its elastic deformation properties to fill the gap between the oxygen-free copper ring 1 and adjacent components, effectively preventing vacuum leakage and ensuring the vacuum seal of the oxygen-free copper ring 1 after installation. The dimensions of the mounting groove 10 match the cross-sectional dimensions of the seal 9, preventing the seal 9 from failing due to excessive compression while ensuring it provides stable sealing pressure, further improving the overall reliability of the microwave window.

[0036] Specifically, the seal 9 is an annular rubber sealing ring used in conjunction with the mounting groove 10, and its cross-sectional shape matches the trapezoidal structure of the mounting groove 10. The mounting groove 10 is formed on both sides of the outer circle of the oxygen-free copper ring 1, and is designed as a trapezoidal groove with a large interior and a small opening. This structure facilitates the embedding and installation of the seal 9, and also prevents the seal 9 from falling off during use by shrinking the groove opening.

[0037] In this embodiment, the seal 9 is embedded into the mounting groove 10 through elastic deformation. Its fixed end (the part in contact with the bottom of the groove) is stably positioned due to the large internal space of the trapezoidal groove, while the narrow groove on the open side restricts the radial movement of the seal 9, ensuring that it always fits the contact surface between the oxygen-free copper ring 1 and adjacent components (such as waveguides or arc cavity flanges) during use. This design not only ensures the reliable fixing of the seal 9, but also utilizes its elastic deformation characteristics to achieve the vacuum sealing function after the oxygen-free copper ring 1 is installed.

[0038] The usage process and operating principle of the adhesive microwave window described in this utility model include: Usage Process: Installation: First, use the connecting holes 7 on the edge of the oxygen-free copper ring 1 and external bolts or locating pins to precisely fix the oxygen-free copper ring 1 onto the mating flange of the waveguide and arc cavity. Simultaneously, utilize the clearance notch 8 to engage with the flange protrusion structure to prevent rotation of the oxygen-free copper ring 1 after installation. Assembly: Fix the AIN sheet 2 into the recessed hole 5 in the middle of the oxygen-free copper ring 1 using adhesive thermally conductive silicone 4, ensuring radial positioning of the AIN sheet 2 and the recessed hole 5. Concentrically install the boron nitride sheet 3 into the locating hole 6 on the side of the oxygen-free copper ring 1 closest to the arc cavity, directly exposing it to the arc cavity environment. Sealing: Embed the annular rubber sealing ring 9 into the trapezoidal mounting grooves 10 on both sides of the outer circumference of the oxygen-free copper ring 1, utilizing the groove's shrinkage characteristics to prevent the sealing ring from falling off. The sealing ring 9 fills the gap between the oxygen-free copper ring 1 and the waveguide / arc cavity flange contact surface through elastic deformation, forming a vacuum seal. After the system is connected and the microwave window is docked with the waveguide and arc cavity, the ECR ion source is started. The microwave is transmitted to the arc cavity through the waveguide, which excites the plasma and generates high-energy electrons. At this time, the boron nitride sheet 3 begins to withstand the bombardment of backflow electrons and plasma ablation, and the AIN sheet 2 enters the impedance matching and sealing working state.

[0039] Operating principle: The operating principle of the adhesive microwave window is based on the synergistic effect of structural design and material properties. The core is to solve the problem of easy damage in traditional brazing processes and improve reliability. 1. Electron bombardment protection: After being accelerated or reflected, the high-energy electrons in the arc cavity preferentially bombard the surface of the boron nitride sheet 3 near the arc cavity (rather than directly acting on the AIN sheet 2); the boron nitride sheet 3, with its high resistance to electron bombardment and ablation resistance, becomes a "protective barrier" for the AIN sheet 2, effectively reducing the risk of contamination or ablation of the AIN sheet 2 caused by direct exposure to the plasma environment.

[0040] 2. Thermal stress buffering: During operation, the AIN sheet 2 may generate edge stress due to heat. At this time, the adhesive thermally conductive silicone 4 absorbs part of the thermal expansion difference through elastic deformation, which alleviates the stress concentration between the AIN sheet 2 and the oxygen-free copper ring 1 (high rigidity) and avoids cracking of the AIN sheet 2 or failure of the seal due to compression.

[0041] 3. Vacuum sealing mechanism: The trapezoidal mounting grooves 10 on both sides of the outer circle of the oxygen-free copper ring 1 cooperate with the annular rubber sealing ring 9. The elastic deformation of the sealing ring 9 fills the tiny gaps in the contact surface, forming a stable vacuum seal. At the same time, the oxygen-free copper ring 1, as the main structure, ensures the concentricity and sealing performance of the AIN sheet 2 and the boron nitride sheet 3 through the precise cooperation of the embedded hole 5 and the positioning hole 6.

[0042] 4. Impedance matching function: As the main functional component of the microwave window, the AIN chip 2 achieves impedance matching between the waveguide and the arc cavity through its material properties (low dielectric loss and high thermal conductivity), ensuring efficient transmission of microwave energy to the arc cavity and maintaining stable plasma excitation.

[0043] In summary, the adhesive microwave window, through a combination of structural optimization (adhesive bonding instead of brazing, boron nitride protective layer) and material properties (thermally conductive silicone buffer, elastic sealing ring), solves the problems of easy damage and complex manufacturing process of traditional microwave window AIN sheets, significantly improving the reliability and maintenance convenience of the ion source.

[0044] All content not described in detail in this specification is prior art known to those skilled in the art, and the model parameters of each component are not specifically limited; conventional equipment can be used. Control elements not mentioned in this technical solution are prior art and are therefore not shown in the figures, and will not be described further here.

[0045] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model.

Claims

1. An adhesive microwave window, comprising an oxygen-free copper ring (1), characterized in that, It also includes an AIN sheet (2) and a boron nitride sheet (3) disposed on the oxygen-free copper ring (1). The AIN sheet (2) and the boron nitride sheet (3) are concentrically disposed on the oxygen-free copper ring (1), and the boron nitride sheet (3) is located on the side of the oxygen-free copper ring (1) close to the arc cavity and is directly exposed to the arc cavity environment. The AIN sheet (2) is connected to the oxygen-free copper ring (1) by bonding thermally conductive silicone (4).

2. The adhesive microwave window as described in claim 1, characterized in that, The oxygen-free copper ring (1) has a central through hole in the middle. The central through hole is designed as a trapezoidal hole structure with a larger inner diameter and a smaller outer diameter. An embedded hole (5) and a positioning hole (6) are respectively provided in the central through hole. The embedded hole (5) matches the AIN sheet (2), and the positioning hole (6) matches the boron nitride sheet (3).

3. The adhesive microwave window as described in claim 2, characterized in that, The central through hole is connected to both the embedded hole (5) and the positioning hole (6).

4. The adhesive microwave window as described in claim 2, characterized in that, The embedded hole (5) is located on the side of the central through hole near the waveguide, and the positioning hole (6) is located on the side of the central through hole near the arc cavity.

5. The adhesive microwave window as described in claim 2, characterized in that, The embedded hole (5) and the AIN sheet (2), and the positioning hole (6) and the boron nitride sheet (3) are all concentrically set.

6. The adhesive microwave window as described in claim 1, characterized in that, The oxygen-free copper ring (1) has several connecting holes (7) on its surface, and the connecting holes (7) are evenly distributed.

7. The adhesive microwave window as described in claim 1, characterized in that, The edge of the oxygen-free copper ring (1) is also provided with several clearance notches (8).

8. The adhesive microwave window as described in claim 1, characterized in that, The oxygen-free copper ring (1) has mounting grooves (10) on both sides of its outer circle, and a seal (9) is provided in the mounting groove (10).

9. The adhesive microwave window as described in claim 8, characterized in that, The seal (9) is an annular rubber seal that matches the mounting groove (10), and its cross-sectional shape matches the trapezoidal structure of the mounting groove (10).

10. The adhesive microwave window as described in claim 8, characterized in that, The mounting groove (10) is a trapezoidal groove with a large interior and a small opening.

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