High-vacuum-tube electronic device and automatic vacuumizing and exhausting equipment

Abstract

The invention relates to a high-vacuum-tube electronic device and vacuumizing exhaust equipment thereof. One end of the electronic device cavity is connected with a hard pipe wall through a corrugated pipe structure, axial stress is borne through a supporting structure, and a pressure sensor is arranged on the supporting structure and used for detecting the vacuum degree. The matched vacuumizing and exhausting equipment comprises a supporting platform with a baking function, a vacuum tube, a vacuum unit composed of a molecular pump and a sputtering ion pump, an air exhaust connecting piece and a disconnecting device. The breaking device comprises a cutting working part and an extrusion sealing working part, the sealing working part seals the copper pipe in a two-section extrusion and electric heating mode, a compact structure is formed, and leakage is effectively prevented. The packaging structure is compact in structure, reliable in sealing and suitable for batch packaging of high-vacuum devices.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electronic device manufacturing, and in particular to a high-vacuum tube electronic device and an automatic vacuum pumping and exhausting device for the high-vacuum tube electronic device. BACKGROUND

[0002] High-vacuum electronic devices are widely used in modern science, medical treatment and industry, and typical representatives include X-ray tubes, electron guns of electron microscopes, vacuum tubes for high-energy electron accelerators, and some precision vacuum sensors. Such devices usually require the interior to reach an extremely high vacuum degree (about 10 -4 ~ 10 -6 Pa or even higher) to ensure the free movement of electrons or radiation particles in the cavity without interference from air molecules, thereby achieving stable and efficient performance.

[0003] Taking an X-ray tube as an example, its main function is to generate X-rays or β-rays for medical diagnosis, industrial defect detection, scientific research experiments and chip manufacturing. The X-ray tube is usually composed of a cavity with a high degree of internal vacuum, and positive and negative electrodes are arranged at both ends of the cavity. By applying a high voltage to accelerate electrons to hit the target, X-rays or β-rays are generated. Since the working principle requires the X-ray tube to maintain an ultra-high vacuum inside for a long time, strict requirements are placed on the cavity sealing, material gas adsorption characteristics and manufacturing process.

[0004] In the prior art, in order to maintain the vacuum state, some high-vacuum electronic devices usually have a vacuum pumping pump on the cavity, and these pumps continuously run to compensate for the slow release of material adsorbed gas. However, this solution has obvious defects. 1. Complex equipment and high cost: the self-contained vacuum pumping pump increases the device volume, structural complexity and energy consumption. 2. Reliability risk: failure of the vacuum pump directly leads to a decrease in the internal vacuum of the device, which may cause the device to be scrapped. 3. Limited vacuum degree: the pumping capacity of the high-vacuum tube electronic device itself is limited, and it is difficult to achieve the extremely high vacuum degree that can be achieved by a professional vacuum pumping machine.

[0005] High-vacuum electronic devices face the following technical problems during manufacturing and long-term use:

[0006] 1. How to remove the self-contained vacuum pumping pump while ensuring an ultra-high vacuum, thereby reducing equipment complexity and operating energy consumption.

[0007] 2. How to efficiently pump vacuum and achieve reliable sealing during the manufacturing process to ensure long-term stable operation of the device.

[0008] 3. How to timely detect the risk of vacuum decline during the use of the device to prevent device failure or scrapping.

[0009] The technical scheme of the present application aims at the problems, and provides a structure design and vacuum extraction and sealing method for large-size and high-vacuum electronic devices, which can be applied to ray tubes and other similar high-vacuum tubes, and solves the problems of high pump dependency, high cost and insufficient reliability in the prior art. SUMMARY

[0010] In view of the above deficiencies or shortcomings in the prior art, the present application first provides a high-vacuum tube electronic device, which no longer needs to be provided with an independent vacuum pump to maintain the high-vacuum degree (internal air pressure less than 10 -4 Pa) of the internal cavity of the high-vacuum tube electronic device.

[0011] Specifically, the high-vacuum tube electronic device comprises a sealed cavity, and a high-vacuum state is maintained in the cavity.

[0012] A section of the tube wall of the cavity is a corrugated tube structure capable of being axially elastically deformed, and both ends of the corrugated tube are connected with hard tube walls; a support structure coaxially arranged with the corrugated tube is arranged on the electronic device, and is used for bearing the axial force generated by the corrugated tube under the action of the internal and external pressure difference.

[0013] A pressure sensor is arranged on the support structure, the internal vacuum degree of the cavity is calculated by detecting the axial force of the corrugated tube, and an alarm signal is generated when the vacuum degree is lower than a preset value.

[0014] In some embodiments, an air extraction connecting part is further arranged on the cavity, which is used for being connected with an external vacuum extraction and exhaust equipment during manufacturing or maintenance, so as to realize internal vacuum extraction and sealing.

[0015] The present application also simultaneously provides a vacuum extraction and exhaust equipment for a high-vacuum tube electronic device, which comprises:

[0016] A support platform is provided with a plurality of mounting stations, and is used for arranging the electronic devices to be extracted.

[0017] A vacuum tube is provided with a plurality of vacuum extraction neck tubes, each of which corresponds to each mounting station and is provided with a flange for connecting an air extraction connecting part.

[0018] A vacuum unit comprises a molecular pump and a sputtering ion pump, which are connected with the vacuum tube through valves, respectively, and the pump and the valves are controlled by a control unit.

[0019] An alternative air extraction connecting part is provided, which comprises a copper pipe in the middle and connecting parts at both ends of the copper pipe, and the connecting parts are connected with the vacuum extraction neck tube and the electronic device to be extracted, respectively.

[0020] A disconnecting device is used for cutting off the copper pipe of the air extraction connecting part after air extraction is completed.

[0021] In some embodiments, the control unit controls the start, stop and valve opening and closing of the molecular pump and the sputtering ion pump according to the pressure value in the vacuum tube;

[0022] When the pressure in the vacuum tube is from atmospheric pressure to 10 -1 Pa, the molecular pump is started for rough pumping, and after the molecular pump is started, the valve between the molecular pump and the vacuum tube is opened;

[0023] When the pressure in the vacuum tube is from 10 -1 Pa to 10 -4 Pa, the molecular pump is maintained in operation, and the switching to the sputtering ion pump is prepared;

[0024] When the pressure in the vacuum tube is less than 10 -4 Pa, the sputtering ion pump is started, and then the valve between the sputtering ion pump and the vacuum tube is opened, while or subsequently the valve between the molecular pump and the vacuum tube is closed, and finally the molecular pump is closed; the sputtering ion pump realizes the high vacuum degree of 10 -4 Pa or above in the vacuum tube.

[0025] In some embodiments, the disconnecting device comprises a cutting working part and a extrusion sealing working part arranged along the copper pipe;

[0026] The cutting working part is arranged at the side of the copper pipe close to the vacuum tube, and comprises a cutting knife and an anvil, which cut the copper pipe of the pumping connecting piece after pumping is completed;

[0027] The extrusion sealing working part is arranged at the side of the copper pipe close to the electronic device, and comprises a first extrusion block and a second extrusion block arranged oppositely, which are used for applying a clamping force to the copper pipe to clamp and seal the copper pipe.

[0028] In some embodiments, the first extrusion block and the second extrusion block are respectively connected to the positive and negative poles of the power supply;

[0029] A thermocouple is arranged in at least one of the first extrusion block and the second extrusion block.

[0030] In some embodiments, the extrusion sealing working part comprises the following working steps:

[0031] Pre-clamping: the two extrusion blocks are close to each other, and the distance is 1.6-1.8 times the thickness of the wall of the clamped copper pipe;

[0032] Heating: the first extrusion block and the second extrusion block are connected to the power supply, the current flows through the clamped part of the copper pipe and makes the copper pipe heat; the current is heated to 550-600℃;

[0033] Final clamping: after the temperature reaches the set temperature, the two extrusion blocks are close to each other again to extrude the copper pipe at an interval of 0.5-1s, and the distance is 1.2-1.6 times the thickness of the wall of the copper pipe;

[0034] Keep warm, two extrusion blocks are static, maintain the clamping copper pipe state; keep the extrusion block power on, maintain the copper pipe temperature, stay for 2-5s;

[0035] Band pressure cooling, two extrusion blocks are static, maintain the clamping copper pipe state, cut off the connection between the extrusion block and the power supply, and the copper pipe is naturally cooled;

[0036] Separation, after the copper pipe is cooled to below 200 DEG C, the two extrusion blocks are away from each other, and the copper pipe is released.

[0037] In some embodiments, the cutting work part includes a cutting knife and an anvil, and the copper pipe is arranged between the cutting knife and the anvil;

[0038] The anvil is provided with a positioning structure to clamp the copper pipe to prevent movement, and is also provided with a groove opposite the cutting knife blade, and the cutting knife blade is inserted into the groove when the copper pipe is cut; the cutting knife is a straight blade, and the cutting knife blade is perpendicular to the movement direction of the cutting knife.

[0039] In some embodiments, the anvil is provided with a protruding sealing shoulder, and the sealing shoulder is located on the side of the groove close to the vacuum tube; the cutting knife is provided with a pressing shoulder matched with the sealing shoulder, and the pressing shoulder and the sealing shoulder extrude the copper pipe at the same time when the cutting knife moves towards the anvil to cut the copper pipe.

[0040] In some embodiments, the extrusion sealing work part and the cutting work part can be synchronous or asynchronous operation;

[0041] Synchronous operation: the first extrusion block is arranged on the anvil, and the second extrusion block and the cutting knife are controlled to move by the same driving device;

[0042] Asynchronous operation: the cutting knife is controlled to move by one driving device, and the two extrusion blocks are controlled to move by another driving device, and in the asynchronous operation mode, the extrusion sealing work part is operated to seal the copper pipe first, and then the cutting work part is operated to cut the copper pipe.

[0043] The high vacuum tube electronic device and the vacuum pumping and exhausting equipment thereof have the following effects:

[0044] The application introduces a section of corrugated pipe as a flexible vacuum connection section in the cavity of the high vacuum tube electronic device, the two ends of the corrugated pipe are connected with the hard pipe wall, the support structure coaxially arranged with the corrugated pipe is used to cross the two sections of hard pipe wall to form the main force structure. The axial resultant force generated by the internal and external pressure difference on the device end face is no longer transmitted through the shell wall or the corrugated section, but is borne by the support structure and transmitted to the sensor.

[0045] The axial force and the internal and external pressure difference form a stable linear relationship (F≈Δp·A, A is the effective cross-sectional area and is basically constant during use; Δp is the internal and external pressure difference of the high-vacuum tube electronic device, wherein the external ambient pressure value can be directly measured by an instrument), which is convenient for accurate conversion of the cavity vacuum degree by the pressure sensor installed on the support structure.

[0046] When the converted vacuum degree is lower than the threshold value, an automatic alarm is given, so as to realize online state monitoring and maintenance decision without damaging the seal. The evacuation connection part provided on the cavity provides a standard interface for manufacturing and later maintenance, and the cavity can be sealed after being evacuated to the target vacuum in the factory; if the vacuum decays after long-term use, the evacuation equipment can be connected again for re-evacuation and re-sealing, so as to reduce the scrap rate and the whole life cost.

[0047] The evacuation and exhaust equipment of the present application adopts a double-pump structure of a molecular pump and a sputtering ion pump, and pressure is controlled in sections for different pressure sections. The molecular pump works efficiently in the interval from atmospheric pressure to 10 -4 Pa, and the sputtering ion pump realizes high-vacuum maintenance in the interval below 10 -4 Pa. Thus, the evacuation time is shortened, the final vacuum degree is improved, and the energy consumption is reduced.

[0048] The replaceable evacuation connecting piece provided in the equipment includes a copper pipe in the middle and connecting parts at both ends, and the copper pipe can be directly sealed and cut off in the middle after evacuation, which not only reduces the consumption cost, but also facilitates quick replacement and reduces downtime.

[0049] In the sealing and cutting-off link, the present application is provided with a combined extrusion sealing working part and a cutting-off working part. The extrusion sealing working part adopts a first extrusion block and a second extrusion block arranged oppositely, a pre-clamping pressure is first applied, then the copper pipe is locally softened by heating, and then a final clamping pressure is applied, so that the metal atoms on both sides of the copper pipe are metallurgically combined under high temperature and high pressure, and the copper pipe is permanently sealed after cooling. The cutting-off working part cuts off the copper pipe near the vacuum tube, and the pressing shoulder and the anvil sealing shoulder form a temporary seal before cutting off to prevent vacuum leakage during cutting off. The combined structure can ensure the high air tightness of the seal and the cleanliness of the cutting-off process.

[0050] In addition, the extrusion sealing working part and the cutting-off working part can work synchronously or asynchronously. In the synchronous mode, the two are controlled by the same driving device, and quick sealing and cutting-off can be realized in batch production; in the asynchronous mode, the two are independently driven, and sealing is performed before cutting-off, which is suitable for precise devices with extremely high vacuum maintenance requirements. This design takes into account the production efficiency and vacuum quality while having strong process adaptability.

[0051] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 This is a simplified structural diagram of the high-vacuum tube electronic device of the present invention;

[0053] Figure 2 This is a simplified structural diagram of the vacuum exhaust device of the present invention.

[0054] Explanation of reference numerals in the attached figures

[0055] 1-Electronic components, 1a-Cavity, 1b-Bellbell, 1c-Rigid tube wall, 1d-Supporting structure

[0056] 2-Support Platform

[0057] 3-Vacuum tube, 3a-Vacuum neck tube

[0058] 4-Molecular pump

[0059] 5-Sputtering Ion Pump

[0060] 6-Evacuation connector, 6a-Copper pipe;

[0061] 7-Cut-off work section,

[0062] 8-Extrusion Sealing Working Section

[0063] 9-Vacuum gauge. Detailed Implementation

[0064] In this invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the orientation in the assembled and used state. "Inner" and "outer" refer to the inner and outer sides relative to the outline of each component itself.

[0065] This invention provides a high-vacuum tube electronic device 1 (see attached document). Figure 1 Specifically, the electronic device 1 includes a sealed cavity 1a, the interior of which is maintained in a high vacuum state. One section of the wall of the cavity 1a is configured as a bellows 1b, with the two ends of the bellows 1b respectively connected to a first rigid tube wall 1c and a second rigid tube wall 1c. The end of the rigid tube wall 1c has an end face. The three are coaxially arranged to form a continuous sealed housing.

[0066] In this embodiment, the bellows 1b serves as a flexible vacuum connection section. Its function is to ensure the vacuum seal continuity of the cavity 1a between the first rigid tube wall 1c and the second rigid tube wall 1c during assembly and operation, while allowing for minor relative displacement or form and position error compensation between the two rigid tube wall sections 1c. The bellows 1b itself does not bear the main axial stress of the device under the action of internal and external pressure difference.

[0067] To bear the axial force generated by the internal and external pressure difference on the end face of the device, the embodiment is provided with a support structure 1d coaxially arranged with the bellows 1b outside the cavity 1a. The two ends of the support structure 1d are fixed on the first hard pipe wall 1c and the second hard pipe wall 1c respectively, thereby forming a main force passage, so that the axial load generated by the internal and external pressure difference is transmitted and borne by the support structure 1d instead of the bellows 1b.

[0068] A pressure sensor is mounted on the support structure 1d and rigidly connected with the support structure 1d, for real-time detection of the axial force borne by the support structure 1d. Since the effective pressure area A of the end face of the cavity 1a is basically constant during the use cycle, the internal and external pressure difference Δp (the external air pressure can be detected by the instrument) and the axial force F satisfy the approximate relationship F≈Δp·A, so that the vacuum degree inside the cavity 1a can be calculated by detecting F. When the calculated vacuum degree is lower than the preset value, the pressure sensor transmits a signal to the control system, and the control system triggers an alarm to prompt maintenance or re-evacuation.

[0069] In the embodiment, an evacuation connecting part is arranged on the cavity 1a. The evacuation connecting part can be connected with an external evacuation and exhaust equipment during the manufacture or maintenance of the device, so that the cavity 1a is sealed after being evacuated to the target vacuum degree. The evacuation connecting part can adopt a flange connection, a threaded connection or other vacuum sealing structure to adapt to the needs of different production lines and maintenance environments.

[0070] The structure has the advantages that the bellows 1b provides vacuum sealing continuity and assembly flexibility, the support structure 1d independently bears the axial force and cooperates with the pressure sensor to realize online vacuum detection, and the evacuation connecting part provides a standardized interface for manufacture and maintenance. This design improves the structural life of the cavity 1a, the vacuum maintaining stability and reduces the maintenance cost.

[0071] Evacuation and exhaust equipment (see FIG. 2) Figure 2 ):

[0072] An evacuation and exhaust equipment for a high-vacuum tube electron device 1, comprising a support platform 2, a vacuum tube 3, a vacuum unit, a replaceable evacuation connecting part 6 and a control unit.

[0073] The support platform 2 is provided with a plurality of mounting stations for fixing the electron device 1 to be evacuated and performing heating and baking treatment. The mounting stations can include electric heating plates, infrared heating devices or other controllable heat sources to heat the electron device 1 during the evacuation process, so that the gases adsorbed on the surface of the device and the cavity 1a are desorbed, thereby shortening the evacuation time and improving the final vacuum degree. The heating temperature and heating curve of each mounting station can be set by an independent control module to adapt to the process requirements of different models of electron devices 1.

[0074] The vacuum pipe 3 is provided with a plurality of vacuum extraction necks 3a at positions corresponding to the mounting stations. The vacuum extraction necks 3a are provided with flange sealing interfaces at their ends for connecting to the vacuum extraction connectors 6. In this embodiment, the vacuum pipe 3 is of a bus type structure, and each mounting station can be connected to the vacuum pipe 3 simultaneously during the vacuum extraction stage, thereby enabling parallel vacuum extraction of a plurality of electronic devices 1.

[0075] The vacuum unit comprises a molecular pump 4 and a sputtering ion pump 5, which are connected to the vacuum pipe 3 through independent valves respectively. The molecular pump 4 is used for rough extraction and medium vacuum stage, and the sputtering ion pump 5 is used for high vacuum maintenance stage. The valves are designed with high vacuum level sealing to avoid external air entering or vacuum degree dropping during switching.

[0076] The control unit is connected to each pump and valve, and automatically controls the start and stop of the pumps and the opening and closing of the valves according to the pressure in the vacuum pipe 3. For example, when the pressure in the vacuum pipe 3 is between atmospheric pressure and 10 -1 Pa, the molecular pump 4 is started and the valve between the molecular pump 4 and the vacuum pipe 3 is opened for rough extraction; when the pressure is reduced to 10 -1 Pa to 10 -4 Pa, the molecular pump 4 is maintained in operation and is ready to switch to the sputtering ion pump 5; when the pressure is lower than 10 -4 Pa, the sputtering ion pump 5 is started and the valve between the molecular pump 4 and the vacuum pipe 3 is closed, achieving high vacuum maintenance.

[0077] Specifically, when the pressure in the vacuum pipe 3 is between atmospheric pressure and 10 -1 Pa, the molecular pump 4 is started for rough extraction, and the molecular pump 4 is started first, and then the valve between the molecular pump 4 and the vacuum pipe 3 is opened;

[0078] When the pressure in the vacuum pipe 3 is between 10 -1 Pa and 10 -4 Pa, the molecular pump 4 is maintained in operation and is ready to switch to the sputtering ion pump 5;

[0079] When the pressure in the vacuum pipe 3 is less than 10 -4 Pa, the sputtering ion pump 5 is started first, and then the valve between the sputtering ion pump 5 and the vacuum pipe 3 is opened; at the same time or subsequently, the valve between the molecular pump 4 and the vacuum pipe 3 is closed, and finally the molecular pump 4 is closed; the sputtering ion pump 5 achieves high vacuum degree of 10 -4 Pa or above in the vacuum pipe 3.

[0080] The vacuum pipe 3 is also connected to a high-precision vacuum gauge 9, which can monitor the actual pressure in the vacuum pipe 3 in real time.

[0081] The replaceable vacuum extraction connector 6 is used to connect the electronic device 1 and the vacuum pipe 3. The connector comprises a copper pipe 6a segment in the middle and connecting portions at both ends, one end of which is connected to the flange of the vacuum pipe 3 neck, and the other end is connected to the flange of the vacuum extraction port of the electronic device 1.

[0082] Compared to existing technologies, traditional vacuum systems often only provide single-station evacuation or lack simultaneous baking functionality, resulting in long evacuation cycles and poor vacuum stability. Some systems require additional equipment handling between evacuation and heating, increasing the risk of contamination and damage. This embodiment achieves simultaneous evacuation and baking operations by directly setting up the heating and baking installation station on the support platform 2, which improves evacuation efficiency and reduces the risk of inter-process transfer. The bus-type vacuum tube 3, combined with a multi-pump staged evacuation method, can simultaneously serve multiple electronic devices 1, improving production cycle time and capacity. The replaceable evacuation connector 6 further reduces maintenance costs and extends the overall lifespan of the equipment.

[0083] The disconnecting device is installed at the vacuum connection 6 of the vacuum exhaust equipment. It is used to cut off the copper pipe 6a connector and seal the end of the electronic device 1 after the vacuum is completed. The disconnecting device mainly includes a cutting working part 7 and a compression sealing working part 8, which can operate synchronously or asynchronously.

[0084] Cut-off work section 7:

[0085] The cutting section 7 is located on the side of the copper tube 6a near the vacuum tube 3. Its main function is to cut the copper tube 6a after evacuation, while simultaneously forming a temporary sealing structure. The cutting section 7 includes a cutting blade and an anvil, with the copper tube 6a positioned between the two.

[0086] Cutting board: The cutting board has a positioning structure for the copper tube 6a, such as a positioning groove and an independent fixing piece, to fix the copper tube 6a and prevent it from moving during the cutting process; the size of the positioning groove is slightly larger than the outer diameter of the copper tube 6a to ensure that the copper tube 6a will not tilt or shift under the action of the blade. A groove is provided on the cutting board, and the cutting blade faces the groove. During the cutting operation, the blade of the cutting blade is inserted into the groove to protect the blade.

[0087] Cutting Blade: The cutting blade is a straight-edged blade with the cutting edge perpendicular to the direction of movement. The blade is designed with a trapezoidal flat top (0.3–0.6 mm) to ensure uniform pressure distribution during cutting and prevent stretching or edge lifting. After the cutting blade first contacts the copper tube 6a at the pressing shoulder and forms a temporary seal with the anvil sealing shoulder, the cutting edge inserts into the positioning groove to complete the cut.

[0088] The fit between the pressing shoulder and the sealing shoulder: The cutting board is also provided with a protruding sealing shoulder, located on the side of the groove near the vacuum tube 3, which is used to fit with the pressing shoulder on the cutting knife or a separate pressing shoulder to form a temporary seal.

[0089] During the cutting process, the compression shoulder contacts the copper tube 6a and applies pressure, causing a localized pressure zone to form on the copper tube 6a. The sealing shoulder and the compression shoulder together form a temporary seal. This design reduces vacuum leakage in the cavity during cutting and provides stable support for subsequent compression sealing.

[0090] The copper tube 6a truncation itself can form a preliminary seal at the port, but the sealing structure only relies on the copper tube 6a body and the cutting extrusion, and there are small gaps and instability, which is easy to seep over time. The temporary sealing is ensured by the cooperation of the pressing shoulder and the sealing shoulder, which ensures that the copper tube 6a port does not rebound or shift during the cutting process, and creates a stable working condition for subsequent extrusion sealing. The geometric design of the cutting knife and the anvil (straight blade, trapezoidal flat top, and vertical blade) ensures that the plastic flow of the copper tube 6a during cutting is controllable and will not produce axial tearing or local collapse.

[0091] Operation steps: First, place the copper tube 6a in the anvil positioning slot, and the cutting knife is close to the copper tube 6a. The pressing shoulder and the sealing shoulder start to clamp the copper tube 6a. When the blade is flattened and cuts the copper tube 6a, the pressing shoulder further clamps the copper tube 6a. Then the blade cuts through the copper tube 6a, and the blade is inserted into the groove. The movement of the pressing shoulder can be designed to be driven by a separate drive device, or it can be driven by the same drive device as the cutting knife.

[0092] Through the precise cooperation of the cutting knife, the anvil, and the pressing shoulder and the sealing shoulder, the cutting work part 7 not only completes the cutting of the copper tube 6a, but also forms a stable preliminary sealing structure, ensuring that the vacuum port is fixed in position and the end face is complete during the subsequent extrusion sealing process, and reducing the risk of micro-leakage. This provides a reliable foundation for extrusion sealing and realizes the high-reliability process logic of "temporary sealing first, then reinforced sealing".

[0093] Extrusion sealing working part 8:

[0094] Although the cutting operation of the copper tube 6a can form a preliminary seal, due to surface defects and oxide films, the seal may fail and slowly leak over time. Extrusion sealing clamps the copper tube 6a wall on both sides by external force, making the copper tube 6a form a stable plastic bond, thereby greatly improving the sealing reliability. To further eliminate micro-leakage, the copper tube 6a is heated to 550-650°C after the extrusion block is energized, which breaks down the surface oxide film of the copper tube 6a, recrystallizes, and solid-state metallurgical bonding occurs, thereby achieving dense sealing.

[0095] The extrusion sealing working part 8 is arranged on the side of the copper tube 6a close to the electronic device 1, and includes a first extrusion block and a second extrusion block arranged opposite along the axis of the copper tube 6a. The extrusion block is controlled by a lead screw drive mechanism to achieve precise position control, and the minimum gap G of the extrusion block is set to G = 1.2t-1.6t, where t is the wall thickness of the copper tube 6a. The first and second extrusion blocks are respectively connected to the positive and negative electrodes of the power supply, and at least one built-in thermocouple is used for temperature monitoring.

[0096] Operation steps:

[0097] Pre-clamping: two extrusion blocks are close to each other to a gap of about 1.6-1.8 times the thickness of the copper tube 6a, and a preliminary clamping force is applied to the copper tube 6a without power or low power preheating.

[0098] Temperature rising stage: while the pre-clamping gap is maintained or slowly pushed forward, power is applied to heat the clamping part of the copper tube 6a to 550-600℃, which is higher than the recrystallization temperature to reduce the rheological resistance and promote plastic flow and interface bonding.

[0099] Final clamping: after the temperature reaches the preset value, the extrusion blocks are close to the copper tube 6a within 0.5-1s, the gap is reduced to 1.2-1.6 times the tube wall thickness, causing 20-40% thickness compression of the two layers of tube wall, breaking and extruding the interface oxide film, and realizing solid phase forging welding or diffusion welding.

[0100] Pressure holding and heat preservation: maintain for 2-5s to maintain the state of the extrusion blocks clamping the copper tube, ensuring that the plastic flow is completed and a dense seal is formed.

[0101] Pressure cooling: maintain the state of the extrusion blocks clamping the copper tube, disconnect the extrusion blocks from the power supply, and allow the copper tube 6a to cool naturally to <200℃ to prevent thermal springback from causing the micro gap to reopen.

[0102] Separation: after cooling is completed, the extrusion blocks are moved away from each other to release the copper tube 6a.

[0103] The working surface of the extrusion block is a circular arc with a radius of 1.0-1.5 times the outer diameter of the copper tube 6a, which avoids sharp necking.

[0104] A thin film thermocouple is embedded in the extrusion block close to the contact surface 1-2mm, and the thermocouple is used to detect the temperature of the extrusion area. The actual temperature is used as a reference to feedback and close-loop control the current to ensure that the temperature is within the design temperature.

[0105] The extrusion sealing working part 8 is also provided with a displacement sensor, a stress sensor and a mechanical limit. The displacement sensor detects the size of the gap. The mechanical limit controls the minimum gap of the two extrusion blocks. The stress sensor monitors the clamping force.

[0106] The embodiment realizes high reliable sealing of the copper tube 6a port, solves the problem of easy failure and micro leakage of the traditional cutting and plugging structure, ensures controllability and repeatability, and can be widely applied to the production process of the high vacuum tube electronic device 1.

[0107] Action steps of the present application:

[0108] 1. Electronic device 1 installation and pretreatment:

[0109] The vacuumized electronic device 1 is placed on the mounting station of the vacuumizing exhaust equipment, which has the baking function, so that the electronic device 1 is heated synchronously during the vacuumizing process to remove the residual moisture and volatile matters in the cavity 1a. The bellows 1b is the connecting structure between the hard pipe walls 1c at both ends of the cavity 1a, which maintains the integrity of the cavity 1a, and the bellows 1b itself does not bear the axial stress.

[0110] 2. Vacuumizing operation:

[0111] Through the cooperation of the vacuum pipe 3, the molecular pump 4 and the sputtering ion pump 5, the rough pumping (from atmospheric pressure to 10 - 1 Pa) is firstly performed by the molecular pump 4, then the medium vacuum maintaining (from 10 -1 Pa to 10 -4 Pa) is performed, and finally the high vacuum (<10 -4 Pa) is realized by the sputtering ion pump 5.

[0112] The control unit automatically controls the start, stop and valve opening and closing of the pump according to the pressure value in the vacuum pipe 3, so as to realize the closed-loop and controllable vacuumizing process.

[0113] The baking function of the mounting station ensures that the water and the volatile components in the internal material of the electronic device 1 and the surface of the copper pipe 6a are fully volatilized during the vacuumizing process, so as to improve the final vacuum stability.

[0114] 3. Operation of the extrusion sealing working part 8:

[0115] In the asynchronous operation mode, the extrusion sealing working part 8 works before the cutting working part 7, so as to preferentially ensure the sealing of the port of the electronic device 1.

[0116] The port of the copper pipe 6a is clamped by the relatively arranged extrusion blocks to form a preliminarily stable sealing structure. The extrusion blocks are electrified to heat the port of the copper pipe 6a to 550-650℃, break the oxidation film on the surface and enhance the plastic flow of the copper material, so as to realize the dense solid-phase combination. The two-stage extrusion, pressure insulation and pressure cooling process are adopted to realize the joint strength, sealing reliability and long-term air tightness.

[0117] 4. Operation of the cutting working part 7:

[0118] The pressing shoulder close to the side of the vacuumizing exhaust equipment contacts the copper pipe 6a to form a temporary sealing with the anvil sealing shoulder; the cutting knife is axially pushed forward to cut the copper pipe 6a.

[0119] The specific embodiments of the application described above do not constitute a limitation on the protection scope of the application. Any various other corresponding changes and modifications made according to the technical concept of the application should be included in the protection scope of the claims of the application.

Claims

1. A high-vacuum tube electronic device, comprising a sealed cavity (1a), wherein a high vacuum state is maintained within the cavity (1a), characterized in that: One section of the wall of the cavity (1a) is a corrugated pipe (1b) structure that can be axially elastically deformed, and the two ends of the corrugated pipe (1b) are respectively connected to the rigid pipe wall (1c); the electronic device (1) is provided with a support structure (1d) arranged coaxially with the corrugated pipe (1b) to bear the axial force generated by the corrugated pipe (1b) under the action of internal and external pressure difference; A pressure sensor is installed on the support structure (1d) to calculate the vacuum level inside the cavity (1a) by detecting the axial force on the bellows (1b), and to generate an alarm signal when the vacuum level is lower than a preset value.

2. The high-vacuum tube electronic device according to claim 1, characterized in that, The cavity (1a) is also provided with a vacuum connection part, which is used to connect with an external vacuum exhaust device during manufacturing or maintenance to achieve internal vacuuming and sealing.

3. A vacuum pumping and degassing device for high-vacuum tube electronic devices, characterized in that, include: The support platform (2) is equipped with several installation stations for setting up the electronic devices (1) that are being evacuated; Vacuum tube (3), the vacuum tube (3) is provided with multiple vacuum neck tubes (3a), each vacuum neck tube (3a) corresponds to each installation station, and is provided with a flange for connecting the air extraction connector (6); The vacuum unit includes a molecular pump (4) and a sputtering ion pump (5), which are connected to the vacuum tube (3) through valves respectively. The pump and its valves are controlled by the control unit. Replaceable vacuum connector (6); the vacuum connector (6) includes a copper tube (6a) in the middle and connecting parts at both ends of the copper tube (6a), the connecting parts being connected to the vacuum neck tube (3a) and the evacuated electronic device, respectively. Disconnection device, used to cut off the copper tube (6a) of the vacuum connector (6) after the vacuuming of the electronic device (1) is completed.

4. The vacuum exhaust device according to claim 3, characterized in that, The control unit controls the start-up, shutdown, and valve opening and closing of the molecular pump (4) and sputtering ion pump (5) based on the pressure value inside the vacuum tube (3); When the pressure inside the vacuum tube (3) is atmospheric pressure to 10 -1 When Pa, start the molecular pump (4) for rough pumping. After the molecular pump (4) is started, open the valve between the molecular pump (4) and the vacuum tube (3). When the pressure inside the vacuum tube (3) is 10 -1 Pa to 10 -4 At Pa, maintain the operation of the molecular pump (4) and prepare to switch to the sputtering ion pump (5); When the pressure inside the vacuum tube (3) is less than 10 -4 At Pa, the sputtering ion pump (5) is turned on, then the valve between the sputtering ion pump (5) and the vacuum tube (3) is opened, and the valve between the molecular pump (4) and the vacuum tube (3) is closed simultaneously or subsequently, and finally the molecular pump (4) is closed; the sputtering ion pump (5) achieves 10 Pa in the vacuum tube (3). -4 High vacuum of over Pa.

5. The vacuum exhaust device according to claim 3, characterized in that, The disconnecting device includes a cutting working part (7) and a compression sealing working part (8) arranged along the copper tube (6a). The cutting section (7) is located on the side of the copper tube (6a) near the vacuum tube (3), and includes a cutting blade and an anvil. After the evacuation is completed, it cuts the copper tube (6a) of the evacuation connector (6). The extrusion sealing working part (8) is provided on the side of the copper tube (6a) close to the electronic device (1), and includes a first extrusion block and a second extrusion block arranged opposite to each other, for applying clamping force to the copper tube (6a) to clamp and seal the copper tube (6a).

6. The vacuum exhaust device according to claim 5, characterized in that, The first and second extrusion blocks are connected to the positive and negative terminals of the power supply, respectively; at least one of the first and second extrusion blocks is equipped with a thermocouple.

7. The vacuum exhaust device according to claim 6, characterized in that, The extrusion sealing working part (8) includes the following working steps: Pre-clamping: Two clamping blocks are brought close to each other, with a distance of 1.6 to 1.8 times the wall thickness of the clamped copper tube (6a); The temperature rises, the first and second extrusion blocks are connected to the power supply, and the current flows through the clamped part of the copper tube (6a) and causes the copper tube (6a) to heat up; the temperature rises to 550-600℃. After the final clamping and heating to the set temperature, the two extrusion blocks are brought close to each other again to extrude the copper tube (6a) after an interval of 0.5 to 1 second, with a distance of 1.2 to 1.6 times the wall thickness of the copper tube (6a); Keep the temperature stable, keep the two extrusion blocks still, and maintain the state of clamping the copper tube (6a); keep the extrusion blocks powered on to maintain the temperature of the copper tube (6a) for 2 to 5 seconds; Under pressure cooling, the two extrusion blocks remain stationary, maintaining the state of clamping the copper tube (6a). The connection between the extrusion blocks and the power supply is cut off, and the copper tube (6a) cools down naturally. After the copper tube (6a) is detached and cooled to below 200°C, the two extrusion blocks move away from each other, releasing the copper tube (6a).

8. The vacuum exhaust device according to claim 5, characterized in that, The cutting workpiece (7) includes a cutting blade and an anvil, with a copper tube (6a) disposed between the cutting blade and the anvil. The cutting board is equipped with a positioning structure to hold the copper tube (6a) in place and prevent it from moving. The cutting board is also equipped with a groove facing the blade of the cutting knife. When cutting the copper tube (6a), the blade is inserted into the groove. The cutting knife is a straight blade, and the blade is perpendicular to the direction of movement of the cutting knife.

9. The vacuum exhaust device according to claim 8, characterized in that, The anvil is provided with a protruding sealing shoulder, which is located on the side of the groove near the vacuum tube (3); the cutting blade is provided with a pressing shoulder that cooperates with the sealing shoulder, and the pressing shoulder and the sealing shoulder simultaneously squeeze the copper tube (6a).

10. The vacuum exhaust device according to claim 5, characterized in that, The compression sealing working part (8) and the cutting working part (7) can operate synchronously or asynchronously; Synchronous operation: The first extrusion block is set on the anvil, and the second extrusion block and the cutting blade are controlled by the same drive device to move; Asynchronous operation: The cutting blade is controlled to move by one drive device, and the two extrusion blocks are controlled to move by another drive device. In the asynchronous operation mode, the extrusion sealing work part (8) first seals the copper tube (6a), and the cutting work part (7) then cuts the copper tube (6a).

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