An internal insulation structure for a scanning electron microscope electron column

Abstract

The utility model relates to scanning electron microscope technical field discloses an inside insulation structure of scanning electron microscope electron cavity, including lens barrel shell, the top of lens barrel shell is connected with the connecting cable. The utility model discloses that the isolation cylinder of lens barrel shell inner wall adopts silicon nitride ceramic, and silicon nitride ceramic is high temperature -resistant and strong insulation, utilizes its high insulation to isolate high -voltage control component and lens barrel shell, and epoxy resin cylinder is wrapped high -voltage control component, and the filling glue between both is filled, and high -voltage control component is tightly wrapped, avoids the electric discharge caused by air gap, and further blocks the current conduction, bottom insulation ring cooperates with polytetrafluoroethylene insulating pad, and the isolation filament holder and lens barrel shell, ensure the insulation isolation of bottom circuit and shell, form multilayer insulation structure, significantly improve the insulation performance inside electron cavity, reduce high -voltage discharge risk, guarantee the stable operation of scanning electron microscope.

Description

Technical Field

[0001] This utility model relates to the field of scanning electron microscopy technology, specifically to an internal insulation structure for the electron cavity of a scanning electron microscope. Background Technology

[0002] A scanning electron microscope (SEM) consists of three main parts: a vacuum system, an electron beam system, and an imaging system. Both the imaging system and the electron beam system are built into a vacuum column. The electron beam system consists of an electron gun and an electromagnetic lens. It is mainly used to generate an electron beam with a very narrow energy distribution and a defined electron energy for scanning and imaging. The electromagnetic lens requires a DC voltage of up to tens of thousands of volts to drive it.

[0003] However, due to design and material limitations, after a period of use (approximately 5-10 years), the insulation material inside the tube containing the high-voltage control components of existing scanning electron microscopes begins to age and its insulation performance deteriorates. This leads to high-voltage discharge within the tube, severely interfering with the normal operation of the scanning electron microscope. Mild cases result in irregular black horizontal stripes on the fluorescent screen, affecting the analytical quality of the microscope or even preventing imaging. Severe cases can damage the electron optics components inside the tube, or even cause high-voltage power supply breakdown. Therefore, the lifespan of scanning electron microscope tubes is generally short. Repair or replacement by the manufacturer is not only expensive (approximately 1 / 5 of the total value of the microscope) but also time-consuming, seriously affecting normal operation. Therefore, this paper proposes an internal insulation structure for the electron cavity of a scanning electron microscope to address the aforementioned problems. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide an internal insulation structure for the electron cavity of a scanning electron microscope, addressing the shortcomings of the prior art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: an internal insulation structure for the electron cavity of a scanning electron microscope, including a microscope tube shell, a connecting cable connected to the top of the microscope tube shell, a filament power control circuit board connected to the inner wall of the top of the microscope tube shell, an isolation cylinder connected to the inner wall of the microscope tube shell, the isolation cylinder being made of silicon nitride ceramic, an epoxy resin cylinder being disposed within the inner cavity of the isolation cylinder, a high-voltage control component being disposed within the inner cavity of the epoxy resin cylinder, a filler rubber being filled between the high-voltage control component and the epoxy resin cylinder, the filler rubber being vulcanized silicone rubber, an insulating ring being disposed below the inner wall of the microscope tube shell, and an annular groove being formed at the bottom of the insulating ring. A polytetrafluoroethylene (PTFE) insulating pad is installed inside the slot. A filament holder is connected to the bottom of the microscope tube shell. The insulating sleeve on the inner wall of the microscope tube shell is made of silicon nitride ceramic. Silicon nitride ceramic is heat-resistant and has strong insulation properties, which are used to isolate the high-voltage control component from the microscope tube shell. An epoxy resin sleeve wraps the high-voltage control component, and the space between the two is filled with filler glue to tightly wrap the high-voltage control component, avoiding discharge caused by air gaps and further blocking current conduction. The bottom insulating ring cooperates with the PTFE insulating pad to isolate the filament holder from the microscope tube shell, ensuring the insulation isolation between the bottom circuit and the shell, forming a multi-layer insulation structure. This significantly improves the insulation performance inside the electron cavity, reduces the risk of high-voltage discharge, and ensures the stable operation of the scanning electron microscope.

[0006] Preferably, the insulating ring is made of barium titanate ceramic, and the outer surface of the insulating ring is provided with a number of micron-sized protrusions. The insulating ring made of barium titanate ceramic has a high dielectric constant and insulation properties. The micron-sized protrusions on the outer surface reduce the contact area of ​​contaminants, making it difficult for dust to adhere, extending the cleaning cycle, reducing the probability of leakage, and enhancing structural stability.

[0007] Preferably, the outer wall of the lens barrel shell is connected to a glue injection pipe, and the left end of the glue injection pipe is connected to a sealing plug. The glue injection pipe is used to inject filler glue between the epoxy resin barrel and the high-pressure control component. After filling, the pipe is sealed with a sealing plug to ensure that the filler glue fills the gap, which facilitates replacement after the filler glue ages and improves maintenance efficiency.

[0008] Preferably, the inner wall of the isolation cylinder is spirally connected to a cooling pipe, the outer wall of the lens barrel shell is connected to a cooling oil tank, the top of the cooling oil tank is connected to an oil pump, the top end of the cooling pipe passes through the isolation cylinder and the lens barrel shell in sequence and is connected to the output end of the oil pump, and the input end of the oil pump is connected to the cooling oil tank through a pipe. By starting the oil pump, the cooling oil in the cooling oil tank is pumped into the cooling pipe on the inner wall of the isolation cylinder. The cooling oil absorbs heat as it flows in the pipe, reducing the operating temperature of the high-voltage control components, avoiding aging of the insulation material caused by high temperature, maintaining long-term insulation stability, and reducing the risk of discharge caused by overheating.

[0009] Preferably, the inner wall of the isolation cylinder is provided with a spiral groove, and the cooling pipe is connected in the groove. The cooling pipe is fixed by the spiral groove on the inner wall of the isolation cylinder, so that the cooling pipe fits tightly against the isolation cylinder and the epoxy resin cylinder, increasing the heat dissipation area and improving the heat transfer efficiency.

[0010] Preferably, the bottom end of the cooling pipe passes through the isolation cylinder and the outer shell of the mirror cylinder in sequence and extends outward, and the extended end is connected to a return pipe. The top end of the return pipe is connected to the cooling oil tank to form a cooling oil circulation loop. After absorbing heat, the cooling oil flows back to the cooling oil tank to cool down, ensuring that the cooling oil is used in a cyclical manner and maintaining the continuity of the heat dissipation effect.

[0011] The present invention adopts the above technical solution, which can bring the following beneficial effects: 1. The internal insulation structure of the electron cavity of this scanning electron microscope utilizes silicon nitride ceramic as an insulating sleeve on the inner wall of the microscope tube. Silicon nitride ceramic is heat-resistant and has strong insulation properties, which are used to isolate the high-voltage control components from the microscope tube shell. An epoxy resin sleeve encapsulates the high-voltage control components, with filler glue filling the gap between them, tightly wrapping the high-voltage control components to prevent discharge caused by air gaps and further blocking current conduction. The bottom insulating ring cooperates with the polytetrafluoroethylene insulating pad to isolate the filament holder from the microscope tube shell, ensuring insulation isolation between the bottom circuit and the shell, forming a multi-layer insulation structure. This significantly improves the insulation performance inside the electron cavity, reduces the risk of high-voltage discharge, and ensures the stable operation of the scanning electron microscope. A glue injection pipe is used to inject filler glue between the epoxy resin sleeve and the high-voltage control components. After filling, the pipe is sealed with a sealing plug to ensure that the filler glue fills the gap, facilitating replacement after the filler glue ages and improving maintenance efficiency.

[0012] 2. The internal insulation structure of the electron cavity of this scanning electron microscope involves pumping cooling oil from the cooling oil tank into the cooling pipe on the inner wall of the isolation cylinder via an oil pump. The cooling oil absorbs heat as it flows within the pipe, reducing the operating temperature of the high-voltage control components, preventing aging of the insulation material due to high temperature, maintaining long-term insulation stability, and reducing the risk of discharge caused by overheating. The bottom end of the cooling pipe is connected to the cooling oil tank via a return pipe, forming a cooling oil circulation loop. After absorbing heat, the cooling oil flows back to the cooling oil tank to cool down, ensuring the continuous use of the cooling oil and maintaining the continuity of the heat dissipation effect. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the front structure of this utility model; Figure 2 This is a front sectional view of the present invention; Figure 3 for Figure 2 Enlarged view of point A; Figure 4 This is a front cross-sectional view of the isolation cylinder of this utility model.

[0014] In the diagram: 1. Lens barrel housing; 2. Connecting cable; 3. Filament power control circuit board; 4. Isolation tube; 5. Epoxy resin tube; 6. High voltage control assembly; 7. Filler adhesive; 8. Insulating ring; 9. PTFE insulating pad; 10. Filament holder; 11. Adhesive injection pipe; 12. Sealing plug; 13. Cooling pipe; 14. Cooling oil tank; 15. Oil pump; 16. Groove; 17. Return pipe. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0017] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "several" means two or more, unless otherwise explicitly specified.

[0019] Please see Figure 1-4One embodiment of this utility model is as follows: an internal insulation structure for the electron cavity of a scanning electron microscope, including a microscope tube shell 1, a connecting cable 2 connected to the top of the microscope tube shell 1, a filament power control circuit board 3 connected to the inner wall of the top of the microscope tube shell 1, an isolation cylinder 4 connected to the inner wall of the microscope tube shell 1, the isolation cylinder 4 being made of silicon nitride ceramic, an epoxy resin cylinder 5 disposed within the inner cavity of the isolation cylinder 4, a high voltage control component 6 disposed within the inner cavity of the epoxy resin cylinder 5, a filler 7 being filled between the high voltage control component 6 and the epoxy resin cylinder 5, the filler 7 being vulcanized silicone rubber, an insulating ring 8 disposed below the inner wall of the microscope tube shell 1, the insulating ring 8 being made of barium titanate ceramic, the outer surface of the insulating ring 8 being provided with several micron-sized protrusions, the insulating ring 8 made of barium titanate ceramic having a high dielectric constant and insulation, the micron-sized protrusions on the outer surface reducing the contact area of ​​contaminants, making it difficult for dust to adhere, extending the cleaning cycle, while reducing the probability of leakage and enhancing structural stability, an annular groove being opened at the bottom of the insulating ring 8, a polytetrafluoroethylene insulating pad 9 being disposed in the annular groove, the microscope tube shell The bottom of the microscope tube 1 is connected to a filament holder 10. The insulating cylinder 4 on the inner wall of the microscope tube 1 is made of silicon nitride ceramic. Silicon nitride ceramic is resistant to high temperature and has strong insulation properties. Its high insulation properties are used to isolate the high voltage control component 6 from the microscope tube 1. The epoxy resin cylinder 5 wraps the high voltage control component 6, and the two are filled with filler 7 to tightly wrap the high voltage control component 6, avoid discharge caused by air gaps, and further block current conduction. The bottom insulating ring 8 cooperates with the polytetrafluoroethylene insulating pad 9 to isolate the filament holder 10 from the microscope tube 1, ensuring the insulation isolation between the bottom circuit and the shell, forming a multi-layer insulation structure, which significantly improves the insulation performance inside the electron cavity, reduces the risk of high voltage discharge, and ensures the stable operation of the scanning electron microscope. The outer wall of the microscope tube 1 is connected to a glue injection pipe 11. The left end of the glue injection pipe 11 is connected to a sealing plug 12. The glue injection pipe 11 is used to inject filler 7 between the epoxy resin cylinder 5 and the high voltage control component 6. After filling, the pipe is sealed with the sealing plug 12 to ensure that the filler 7 fills the gap, which is convenient for replacement after the filler 7 ages, improving maintenance efficiency.

[0020] Working principle: The insulating cylinder 4 on the inner wall of the lens barrel shell 1 is made of silicon nitride ceramic. Silicon nitride ceramic is resistant to high temperature and has strong insulation properties. Its high insulation properties are used to isolate the high voltage control component 6 from the lens barrel shell 1. The epoxy resin cylinder 5 wraps the high voltage control component 6, and the space between the two is filled with filler 7, which tightly wraps the high voltage control component 6 to avoid discharge caused by air gaps and further block current conduction. The bottom insulating ring 8 cooperates with the polytetrafluoroethylene insulating pad 9 to isolate the filament holder 10 from the lens barrel shell 1, ensuring the insulation isolation between the bottom circuit and the shell, forming a multi-layer insulation structure, which significantly improves the insulation performance inside the electronic cavity. The filler 7 is injected into the space between the epoxy resin cylinder 5 and the high voltage control component 6 through the glue injection pipe 11. After filling, the pipe is sealed with a sealing plug 12 to ensure that the filler 7 fills the gap, which is convenient for replacement after the filler 7 ages.

[0021] Please see Figure 1-4 Based on the above embodiments, in another embodiment of this utility model, a cooling pipe 13 is spirally connected to the inner wall of the isolation cylinder 4. A spiral groove 16 is formed on the inner wall of the isolation cylinder 4, and the cooling pipe 13 is connected in the groove 16. The cooling pipe 13 is fixed by the spiral groove 16 on the inner wall of the isolation cylinder 4, so that the cooling pipe 13 fits tightly against the isolation cylinder 4 and the epoxy resin cylinder 5, increasing the heat dissipation area and improving the heat transfer efficiency. A cooling oil tank 14 is connected to the outer wall of the lens barrel shell 1, and an oil pump 15 is connected to the top of the cooling oil tank 14. The top end of the cooling pipe 13 passes through the isolation cylinder 4 and the lens barrel shell 1 in sequence and is connected to the output end of the oil pump 15. The input end of the oil pump 15 is connected to the... The cooling oil tank 14 is connected to the cooling oil pipe 13 on the inner wall of the isolation cylinder 4 by starting the oil pump 15. The cooling oil absorbs heat as it flows in the pipe, reducing the operating temperature of the high-voltage control component 6, avoiding aging of the insulation material caused by high temperature, maintaining long-term insulation stability, and reducing the risk of discharge caused by overheating. The bottom end of the cooling pipe 13 passes through the isolation cylinder 4 and the outer shell 1 of the mirror tube in sequence and extends outward. The extended end is connected to the return pipe 17. The top end of the return pipe 17 is connected to the cooling oil tank 14 to form a cooling oil circulation loop. After absorbing heat, the cooling oil flows back to the cooling oil tank 14 to cool down, ensuring that the cooling oil is used in a cyclical manner and maintaining the continuity of heat dissipation.

[0022] Working principle: By starting the oil pump 15, the cooling oil in the cooling oil tank 14 is pumped into the cooling pipe 13 on the inner wall of the isolation cylinder 4. The cooling oil absorbs heat as it flows in the pipe, reducing the operating temperature of the high-voltage control component 6, avoiding aging of the insulation material caused by high temperature, maintaining long-term insulation stability, and reducing the risk of discharge caused by overheating. The bottom end of the cooling pipe 13 is connected to the cooling oil tank 14 through the return pipe 17 to form a cooling oil circulation loop. After absorbing heat, the cooling oil flows back to the cooling oil tank 14 to cool down, ensuring the cooling oil is used in a cyclical manner and maintaining the continuity of heat dissipation.

[0023] It is worth noting that the filament power control circuit board 3, high voltage control component 6, and oil pump 15 in the above embodiments are all commonly used devices in the prior art. The models used can be customized according to actual usage requirements. Furthermore, the power supply interface of the electrical equipment in this utility model is connected to the power supply system through a switch (not shown in the figure) and wires (not shown in the figure) to achieve control. The circuit control, specific composition, and principle involved are all prior art and are known in the current field. They are clear to those skilled in the art, so they will not be described in detail here.

[0024] This invention provides an internal insulating structure for the electron cavity of a scanning electron microscope. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technology.

Claims

1. An internal insulation structure for the electron cavity of a scanning electron microscope, comprising a microscope tube shell (1), wherein a connecting cable (2) is connected to the top of the microscope tube shell (1), and a filament power control circuit board (3) is connected to the inner wall of the top of the microscope tube shell (1), characterized in that: An isolation cylinder (4) is connected to the inner wall of the lens barrel shell (1). The isolation cylinder (4) is made of silicon nitride ceramic. An epoxy resin cylinder (5) is provided in the inner cavity of the isolation cylinder (4). A high-voltage control component (6) is provided in the inner cavity of the epoxy resin cylinder (5). A filler (7) is filled between the high-voltage control component (6) and the epoxy resin cylinder (5). An insulating ring (8) is provided at the bottom of the inner wall of the lens barrel shell (1). An annular groove is opened at the bottom of the insulating ring (8). A polytetrafluoroethylene insulating pad (9) is provided in the annular groove. A filament holder (10) is connected to the bottom of the lens barrel shell (1).

2. The internal insulation structure of the electron cavity of a scanning electron microscope according to claim 1, characterized in that: The insulating ring (8) is made of barium titanate ceramic, and the outer surface of the insulating ring (8) is provided with several micron-sized protrusions.

3. The internal insulation structure of the electron cavity of a scanning electron microscope according to claim 1, characterized in that: The outer wall of the lens barrel shell (1) is connected to a glue injection pipe (11), and a sealing plug (12) is connected to the left end of the glue injection pipe (11).

4. The internal insulation structure of the electron cavity of a scanning electron microscope according to claim 1, characterized in that: The inner wall of the isolation cylinder (4) is spirally connected to a cooling pipe (13), the outer wall of the lens barrel shell (1) is connected to a cooling oil tank (14), the top of the cooling oil tank (14) is connected to an oil pump (15), the top of the cooling pipe (13) passes through the isolation cylinder (4) and the lens barrel shell (1) in sequence and is connected to the output end of the oil pump (15), and the input end of the oil pump (15) is connected to the cooling oil tank (14) through a pipe.

5. The internal insulation structure of the electron cavity of a scanning electron microscope according to claim 4, characterized in that: The inner wall of the isolation cylinder (4) is provided with a spiral groove (16), and the cooling pipe (13) is connected in the groove (16).

6. The internal insulation structure of the electron cavity of a scanning electron microscope according to claim 4, characterized in that: The bottom end of the cooling pipe (13) passes through the isolation cylinder (4) and the outer shell of the mirror cylinder (1) in sequence and extends outward, and the extended end is connected to the return pipe (17). The top end of the return pipe (17) is connected to the cooling oil tank (14).

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