Welding device of metal diaphragm for capacitance film vacuum gauge

Abstract

The invention relates to the technical field of vacuum test instruments, in particular to a high-sensitivity metal diaphragm welding method for a capacitive thin film vacuum gauge. Comprising a vacuum chamber, a diaphragm vertical pressure change adjusting system, a diaphragm horizontal tension adjusting system, a reference cavity cylinder, a measuring cavity cylinder, a welding diaphragm and an infrared positioning instrument. Wherein the reference cavity cylinder, the measuring cavity cylinder and the welding diaphragm form a sensor welding assembly. Before welding, the welding diaphragm is placed between the reference cavity cylinder and the measuring cavity cylinder, after positioning of all parts in the sensor welding assembly is completed through the infrared positioning instrument, the tensile stress of the diaphragm is adjusted through the horizontal tension adjusting system, and the pressing force of the reference cavity cylinder, the measuring cavity cylinder and the metal diaphragm is adjusted through the vertical pressure change adjusting system. And after assembling, positioning and fastening of the diaphragm welding assembly are completed, a vacuum brazing system is started, and high-flatness reliable connection of the metal diaphragms is achieved according to a set vacuum brazing process and set tensile force.

Description

Technical Field

[0001] The invention relates to a welding device for a metal diaphragm used in a capacitance film vacuum gauge, belonging to the technical field of vacuum testing instruments, and in particular to a high-sensitivity welding device for a metal diaphragm used in a capacitance film vacuum gauge. Background Art

[0002] Capacitance film vacuum gauge is a full-pressure vacuum gauge. Different from resistance vacuum gauge, thermocouple vacuum gauge and ionization vacuum gauge with the same range, capacitance film vacuum gauge has nothing to do with the gas composition of the measured vacuum environment, and can fully and truly reflect the real pressure of the vacuum environment. Capacitance film vacuum gauge is the best choice for semiconductor manufacturing equipment such as etching, PVD, ALD and vacuum traceability calibration due to its high accuracy, good repeatability and fast response speed.

[0003] The use of Inconel alloy film as the capacitance sensing element is the mainstream form of capacitance vacuum gauges today. Compared with ceramic capacitance film, this structure has the advantages of high sensitivity and low processing cost. The working principle of capacitance film vacuum gauge is: when the pressure in the vacuum chamber changes, the deflection of the welding film changes, causing the distance between the two electrodes (reference electrode and measuring electrode) to change, and finally the pressure change of the vacuum environment is reflected by the change of capacitance.

[0004] The thickness of the metal diaphragm is usually between 0.02 and 0.05 mm. As the lower limit of vacuum control and control accuracy of advanced semiconductor processes gradually improve, the requirements for the lower limit of measurement of capacitance film vacuum gauges are getting lower and lower, and the sensitivity requirements are getting higher and higher. In particular, the demand for capacitance film vacuum gauges with a range of 0.1 torr and below is growing rapidly, so the thickness of the diaphragm is required to be less than 0.02 mm. Currently, due to the traditional means of resistance welding and laser welding, the metal diaphragm as the sensing electrode cannot be connected to the sensor smoothly and reliably, resulting in low-range capacitance film vacuum gauges being only in the hands of a few European and American companies, and unable to achieve large-scale production, which seriously restricts the development of related industries. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art, to propose a welding device for a metal diaphragm for a capacitance film vacuum gauge, to adopt a vacuum brazing method, to achieve high-flatness, high-efficiency and reliable welding of nickel alloy films below 0.02 mm through high-precision adjustment of stress in the horizontal and vertical directions of the metal film, directional layout of flux and solder, limitation of solder melting space and control of stress release direction during welding. At the same time, in the process of vacuum brazing, stress relief heat treatment of measuring cavity cylinders, reference cavity cylinders and welding diaphragms during processing is achieved. The technical solution involved in this application provides a new technical route for the development of capacitance film vacuum gauges with a range of 0.1 torr and below.

[0006] The technical solution of the present invention is:

[0007] A welding device for a metal diaphragm for a capacitance thin film vacuum gauge comprises a vacuum chamber, a diaphragm vertical pressure change adjustment system, a diaphragm horizontal tension adjustment system, a reference cavity cylindrical cylinder, a measuring cavity cylindrical cylinder, a welding diaphragm, an infrared locator and a radiation heating screen;

[0008] Three sets of diaphragm horizontal tension adjustment systems are provided on the circumference of the vacuum chamber, a diaphragm vertical pressure change sensing mechanism is provided at the bottom of the vacuum chamber, and a vertical pressure change stepping mechanism is provided on the upper part of the vacuum chamber.

[0009] Furthermore, the vacuum chamber provides vacuum pressure guarantee for the vacuum brazing process, the horizontal tension adjustment system, the vertical pressure change sensing mechanism and the vertical pressure change sensing mechanism provide horizontal tensile stress and vertical compressive stress for the welding diaphragm, the observation window is used to observe the horizontal and vertical adjustment of the diaphragm state, and the radiation heating screen provides temperature guarantee for vacuum brazing.

[0010] Specifically, the vertical pressure change sensing mechanism on the bottom of the vacuum chamber and the vertical pressure change stepping mechanism on the upper cover of the vacuum chamber together constitute a diaphragm vertical pressure change adjustment system, and the reference cavity cylindrical cylinder, the measuring cavity cylindrical cylinder, and the welded diaphragm constitute a sensor welding assembly.

[0011] Furthermore, the bottom of the measuring cavity cylinder of the sensor welding assembly is placed on the vertical pressure change sensing mechanism, and then the diaphragm, the reference cavity cylinder and the annular solder are placed in sequence.

[0012] Specifically, after the positioning groove of the measuring cavity cylindrical tube is inserted into the planar boss on the vertical pressure-change sensing mechanism, the infrared locator positioning ring concentric with it marked by the infrared locator is used as a reference standard to fine-tune the position of the measuring cavity cylindrical tube on the plane of the vertical pressure-change sensing mechanism to determine the placement position of the measuring cavity cylindrical tube.

[0013] Specifically, the infrared locator positioning ring concentric with the infrared locator is used as a reference standard to fine-tune the position of the welding diaphragm in the measuring cavity cylinder to determine the placement position of the welding diaphragm.

[0014] Specifically, the position of the reference cavity cylindrical tube on the film is fine-tuned by using the infrared locator positioning ring concentric with the infrared locator mark as a reference standard to determine the placement position of the reference cavity cylindrical tube.

[0015] Furthermore, the horizontal tension of the diaphragm is determined by adjusting three horizontal tension adjustment systems on the side circumference of the vacuum chamber, and the vertical pressure change of the welded diaphragm is achieved by the vertical pressure change adjustment system.

[0016] Specifically, the horizontal tension adjustment system drives the displacement of the horizontal welding bellows by adjusting the stepping amount of the horizontal tension adjustment bolt installed on the horizontal tension positioning nut hole.

[0017] Specifically, the displacement of the horizontal welded bellows further drives the deformation of the horizontal compression spring, thereby generating a compression sensing force on the horizontal tension sensor in contact with it, and the horizontal tensile stress of the triangular welded diaphragm is accurately controlled by the size of the compression sensing force.

[0018] Furthermore, the displacement of the vertical compression stepping mechanism at the upper part of the vacuum chamber is realized by driving the displacement of the welding bellows by the advance and retreat of the vertical compression adjusting bolt.

[0019] Furthermore, the displacement of the vertical pressure-variable stepping mechanism further drives the vertical compression spring inside the vertical pressure-variable sensing mechanism to obtain the sensing force of the diaphragm vertical pressure sensor.

[0020] Furthermore, the displacement zero point of the vertical pressure-variable stepping mechanism is based on the contact resistance between the vertical pressure-variable sensing mechanism and the vertical pressure-variable stepping mechanism.

[0021] Specifically, when the resistance between the direct pressure-variable sensing mechanism and the vertical pressure-variable stepping mechanism changes from infinity to the ohm level, it serves as the adjustment origin of the vertical pressure-variable stepping mechanism.

[0022] Furthermore, the welded diaphragm is an equilateral triangle structure, and the diaphragm triangle is connected to three sets of horizontal tension adjustment systems through drawing wires. The vertical adjustment bolt on the straight compression positioning nut hole is slowly adjusted, and the wedge-shaped structure of the reference cavity cylinder is used to deform the diaphragm, thereby further reducing the strain of the diaphragm during welding and extending to the capacitance measurement part.

[0023] Furthermore, a circular flux coating is provided in the middle of the triangular diaphragm in a semi-coating manner, and the flux coating can be a nickel-plated coating.

[0024] Furthermore, the reference cavity cylindrical tube is in the form of a sleeve, and an annular solder is provided in the middle of the sleeve, and the solder can be silver-copper solder.

[0025] Furthermore, the inner cylinder of the reference cavity cylindrical cylinder is provided with a wedge-shaped structure for increasing the pressing force of the diaphragm.

[0026] Furthermore, a positioning groove is provided on the lower plane of the measuring cavity cylinder, and a wedge-shaped structure for raising the height of the diaphragm is provided on the outer edge of the upper plane to prevent the annular solder from overflowing.

[0027] Furthermore, the wedge shape of the reference cavity cylinder is higher than the wedge shape of the measuring cavity, so as to ensure the pressing force of the wedge shape structure of the reference cavity cylinder on the welding diaphragm.

[0028] Furthermore, a groove is provided on the plane of the cylindrical barrel of the measuring cavity, and a brazing solder layer is coated in the groove, and the solder layer can be silver-copper solder.

[0029] Furthermore, the annular nickel-plated coating in the middle of the diaphragm is arranged in the middle position of the planar groove on the measuring cavity cylinder to ensure the control of the brazing range of the diaphragm.

[0030] Furthermore, the inner cylinder wedge structure of the reference cavity cylinder, the plane wedge structure on the measuring cavity cylinder and the plane groove on the measuring cavity cylinder form a directional melting zone of the solder.

[0031] Furthermore, after completing the sensor welding assembly, the tension of the horizontal tension adjustment system is reset to zero, forming a horizontal stress free end of the diaphragm to ensure that the thermal stress generated by the diaphragm during the brazing process can be released to the free end, further reducing the impact on the flatness of the measuring part of the diaphragm.

[0032] Furthermore, the vacuum chamber is provided with a radiation heating screen, a horizontal tension adjustment system, a vertical pressure change sensing mechanism, a vertical pressure change stepping mechanism, and an observation window, and the horizontal tension adjustment system and the vertical tension adjustment system outside the vacuum chamber are provided with a water cooling circulation system.

[0033] Furthermore, the vacuum chambers equipped with the sensor welding components can form a ring array or other parallel forms and be connected to the vacuum brazing system to achieve batch brazing.

[0034] The present application relates to the technical field of vacuum testing instruments, and more specifically, to a method for welding a high-sensitivity metal diaphragm for a capacitance film vacuum gauge. It includes a vacuum chamber, a diaphragm vertical pressure change adjustment system, a diaphragm horizontal tension adjustment system, a reference cavity cylindrical cylinder, a measuring cavity cylindrical cylinder, a welding diaphragm, and an infrared locator. Among them: the reference cavity cylindrical cylinder, the measuring cavity cylindrical cylinder, and the welding diaphragm constitute a sensor welding assembly. Before welding, the welding diaphragm is placed between the reference cavity cylindrical cylinder and the measuring cavity cylindrical cylinder. After the positioning of the internal components of the sensor welding assembly is completed with the help of an infrared locator, the tensile stress of the diaphragm is adjusted by the horizontal tension adjustment system, and the vertical pressure change adjustment system adjusts the clamping force between the reference cavity cylindrical cylinder, the measuring cavity cylindrical cylinder, and the metal diaphragm. After the assembly, positioning, and tightening of the diaphragm welding assembly are completed, the vacuum brazing system is turned on, and the metal diaphragm is reliably connected with high flatness according to the set tension force according to the set vacuum brazing process. The high-sensitivity metal diaphragm welding method involved in this application adopts the overall heating of the sensor welding assembly, and the deformation caused by thermal stress is uniform, eliminating the problem of diaphragm wrinkles caused by local temperature unevenness in conventional laser welding and electronic welding. Further, through the specific structural design of the cavity cylinder, the measuring cavity cylinder and the welding diaphragm, precision welding without margin is achieved. It provides a new technical path for the connection of high-sensitivity metal diaphragms for capacitive thin film vacuum gauges, which can be used for the manufacture of thin film vacuum gauges below 0.1 torr. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings constituting a part of this application are used to provide a further understanding of this application, so that other features, purposes and advantages of this application become more obvious. The schematic embodiment drawings and their descriptions of this application are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0036] Figure 1 It is a schematic diagram of a high-sensitivity metal diaphragm welding method for a capacitance thin film vacuum gauge provided in an embodiment of the present application;

[0037] Figure 2 It is a schematic diagram of a vertical pressure change sensing mechanism of a high-sensitivity metal diaphragm welding method for a capacitance film vacuum gauge provided in an embodiment of the present application;

[0038] Figure 3 It is a schematic diagram of a sensor welding assembly according to a high-sensitivity metal diaphragm welding method for a capacitance film vacuum gauge provided in an embodiment of the present application;

[0039] Figure 4 It is a schematic diagram of a brazing welding position and a partial enlargement of the structure of a high-sensitivity metal diaphragm welding method for a capacitance film vacuum gauge provided in an embodiment of the present application;

[0040] Figure 5Schematic diagram of a horizontal tension adjustment system of a high-sensitivity metal diaphragm welding method for a capacitance film vacuum gauge provided in an embodiment of the present application;

[0041] Figure 6 It is a schematic diagram of a vertical pressure-variable stepping mechanism of a high-sensitivity metal diaphragm welding method for a capacitance film vacuum gauge provided in an embodiment of the present application;

[0042] Figure 7 It is a schematic diagram of batch welding of sensor welding components according to the high-sensitivity metal diaphragm welding method for capacitive film vacuum gauges provided in an embodiment of the present application.

[0043] In the figure: 1-vacuum chamber, 2-observation window, 3-vertical pressure change sensing mechanism, 31-vertical welding bellows, 32-vertical compression spring, 4-vertical pressure sensor, 5-sensor welding assembly, 51-reference cavity cylindrical tube, 52-annular solder, 53-welding diaphragm, 54-measuring cavity cylindrical tube, 55-measuring cavity positioning groove, 511-annular solder placement groove, 512 reference cavity lower plane wedge structure, 531-welding diaphragm annular coating 1, 532-welding diaphragm annular coating 2, 541-brazing solder layer, 542-measuring cavity horizontal plane wedge structure, 6-horizontal tension adjustment system, 6 1- horizontal tension adjustment bolt, 62- horizontal tension positioning nut hole, 63- horizontal tension sensor, 64- horizontal compression spring, 65- horizontal compression spring mounting hole, 66- horizontal welding bellows, 67- horizontal tension wire drawing fastening hole, 7- vertical compression stepping mechanism, 71- vertical compression adjustment bolt, 72- vertical compression positioning nut hole, 73- vertical compression compression spring mounting hole, 74- vertical welding bellows, 8 infrared locator, 9- welding sensor assembly positioning and stretching diagram, 10- infrared locator reference positioning ring, 11- radiation heating screen, 12- batch brazing system diagram. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0045] A high-sensitivity metal diaphragm welding method for a capacitance thin film vacuum gauge includes a vacuum chamber, a diaphragm vertical pressure change adjustment system, a diaphragm horizontal tension adjustment system, a reference cavity cylinder, a measuring cavity cylinder, a diaphragm, an infrared locator, and a radiation heating screen. Among them:

[0046] The circumference of the vacuum chamber is provided with three groups of diaphragm horizontal tension adjustment systems, the bottom of the vacuum chamber is provided with a diaphragm vertical pressure change sensing mechanism, and the upper part of the vacuum chamber is provided with a vertical pressure change stepping mechanism.

[0047] The vertical pressure change sensing mechanism and the vertical pressure change stepping mechanism together constitute a diaphragm vertical pressure change regulating system.

[0048] The reference cavity cylindrical cylinder, the measuring cavity cylindrical cylinder and the welding diaphragm constitute a sensor welding assembly.

[0049] The bottom of the measuring cavity cylinder of the sensor welding assembly is placed on the upper plane of the vertical pressure change sensing mechanism, and the welding diaphragm, the reference cavity cylinder and the annular solder are placed in sequence.

[0050] The positions of the reference cavity cylindrical tube, the measuring cavity cylindrical tube and the welding diaphragm in the sensor welding assembly in the vacuum chamber are positioned by an infrared positioning instrument.

[0051] The horizontal tension of the welded diaphragm is provided by adjusting three horizontal tension adjustment systems of the circumference of the vacuum chamber, and the vertical compressive stress of the diaphragm is provided by the diaphragm vertical pressure change adjustment system.

[0052] The horizontal tension adjustment system is realized by adjusting the advance and retreat of the bolt to drive the displacement of the welded bellows.

[0053] The displacement of the welded bellows further drives the deformation of the horizontal compression spring to the sensing force of the horizontal tension sensor, so as to accurately control the horizontal tensile stress of the diaphragm.

[0054] The displacement of the vertical pressure-changing stepping mechanism on the upper part of the vacuum chamber is achieved by driving the displacement of the welding bellows by the advance and retreat of the adjusting bolt.

[0055] The displacement of the vertical pressure-variable stepping mechanism further drives the compression spring inside the vertical pressure-variable sensing mechanism to obtain the sensing force of the diaphragm vertical pressure sensor.

[0056] The displacement zero point of the vertical pressure-variable stepping mechanism is based on the contact resistance between the vertical pressure-variable sensing mechanism and the vertical pressure-variable stepping mechanism.

[0057] The diaphragm is an equilateral triangle structure, and the diaphragm triangles are connected to three sets of horizontal tension adjustment systems through drawing wires.

[0058] A circular nickel-plated coating is provided in the middle of the triangular diaphragm.

[0059] The reference cavity cylindrical tube is in the form of a sleeve, and an annular solder is arranged in the middle of the sleeve.

[0060] The inner cylinder of the reference cavity cylindrical cylinder is provided with a wedge-shaped structure for increasing the pressing force of the diaphragm.

[0061] A positioning groove is arranged on the lower plane of the cylindrical tube of the measuring cavity, and a wedge-shaped structure for raising the height of the diaphragm is arranged on the outer edge of the upper plane.

[0062] The reference cavity cylindrical wedge is higher than the measuring cavity wedge.

[0063] A groove is arranged on the upper plane of the measuring cavity cylinder, and brazing solder is coated in the groove.

[0064] The middle annular nickel-plated coating of the welding diaphragm is arranged at the middle position of the plane groove on the cylinder of the measuring cavity.

[0065] The inner cylinder wedge structure of the reference cavity cylinder, the flat wedge structure on the measuring cavity cylinder and the flat groove on the measuring cavity cylinder form a directional melting zone of the solder.

[0066] A high-sensitivity metal diaphragm welding method for a capacitance thin film vacuum gauge. A vacuum chamber equipped with a sensor welding assembly can form a ring array or other parallel forms and be connected to a vacuum brazing system to achieve batch brazing.

[0067] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0068] like Figure 1-7 As shown, the present application provides a high-sensitivity metal diaphragm welding method for a capacitance thin film vacuum gauge, comprising a vacuum chamber 1, an observation window 2, a vertical pressure change sensing mechanism 3, a vertical pressure sensor 4, a sensor welding assembly 5, a horizontal tension regulator system 6, a vertical pressure change stepping mechanism 7, an infrared locator 8, and a radiation heating screen 11. Three groups of diaphragm horizontal tension adjustment systems 6 are arranged around the vacuum chamber 1, a diaphragm vertical pressure change sensing mechanism 3 is arranged at the bottom of the vacuum chamber 1, and a vertical pressure change stepping mechanism 7 is arranged at the top of the vacuum chamber 1.

[0069] Furthermore, the vacuum chamber 1 provides vacuum pressure guarantee for the vacuum brazing process, the horizontal tension adjustment system 6, the vertical pressure change sensing mechanism 3 and the vertical pressure change sensing mechanism 7 provide horizontal tensile stress and vertical compressive stress for the welding diaphragm 53, the observation window 2 is used to observe the state of the horizontal and vertical adjustment diaphragm 53, and the radiation heating screen 11 provides temperature guarantee for vacuum brazing.

[0070] Specifically, the vertical pressure change sensing mechanism 3 on the bottom of the vacuum chamber and the vertical pressure change stepping mechanism 7 on the upper cover of the vacuum chamber together constitute a diaphragm vertical pressure change adjustment system, and the reference cavity cylindrical tube 51, the measuring cavity cylindrical tube 54, and the welded diaphragm 53 constitute a sensor welding assembly 5.

[0071] Furthermore, the bottom of the measuring cavity cylinder 54 of the sensor welding assembly 5 is placed on the upper plane of the vertical pressure change sensing mechanism 3, and then the welding diaphragm 53, the reference cavity cylinder 51 and the annular solder 52 are placed in sequence.

[0072] Specifically, after the positioning groove of the measuring cylindrical cavity 54 is inserted into the planar boss on the vertical pressure-change sensing mechanism 3, the infrared locator positioning ring 10 concentric with the infrared locator 8 is used as a reference standard to fine-tune the position of the cylindrical measuring cavity 54 on the plane of the vertical pressure-change sensing mechanism 3 to accurately determine the placement position of the measuring cavity cylindrical cavity 54.

[0073] Specifically, the infrared locator positioning ring 10 concentric with the infrared locator 8 is used as a reference standard to fine-tune the position of the welding diaphragm 53 in the cylindrical measuring cavity cylindrical tube 54 to determine the placement position of the welding diaphragm 53.

[0074] Specifically, the infrared locator positioning ring 10 concentric with the infrared locator 8 is used as a reference standard to fine-tune the position of the reference cavity cylindrical tube 54 on the film 53 to determine the placement position of the reference cavity cylindrical tube 54.

[0075] Furthermore, the determination and control of the horizontal tension of the welding diaphragm 53 is provided by adjusting the three horizontal tension adjustment systems 6 of the vacuum chamber, and the vertical pressure change of the welding diaphragm 53 is achieved by the vertical pressure change adjustment system.

[0076] Specifically, the horizontal tension adjustment system 6 is realized by adjusting the stepping amount of the horizontal tension adjustment bolt 61 installed on the horizontal tension positioning nut hole 62 to drive the displacement of the horizontal welding bellows 66 .

[0077] Specifically, the displacement of the horizontal welding bellows 66 further drives the deformation of the horizontal compression spring 64 and generates a compression sensing force on the horizontal tension sensor 63 in contact therewith, and the horizontal tensile stress of the welding diaphragm 53 in the triangular direction is precisely controlled by the compression sensing force.

[0078] Furthermore, the displacement of the vertical compression stepping mechanism 7 at the upper part of the vacuum chamber 1 is achieved by driving the displacement of the vertical welding bellows 31 through the stepping of the vertical compression adjusting bolt 71 .

[0079] Furthermore, the displacement of the vertical pressure-change stepping mechanism 7 further drives the compression spring 32 inside the vertical pressure-change sensing mechanism 3 to obtain the sensing force of the welding diaphragm 53 in the vertical direction.

[0080] Furthermore, the displacement zero point of the vertical compression-variable stepping mechanism 7 is based on the contact resistance between the vertical compression-variable sensing mechanism 3 and the vertical compression-variable stepping mechanism 7 .

[0081] Specifically, when the resistance between the vertical pressure-variable sensing mechanism 3 and the vertical pressure-variable stepping mechanism 7 changes from infinity to ohm level, it serves as the adjustment origin of the vertical pressure-variable stepping mechanism 7;

[0082] Furthermore, the welding diaphragm 53 is an equilateral triangle structure, and the diaphragm triangle is connected to three sets of horizontal tension adjustment systems 6 through drawing wires. The vertical adjustment bolt 71 on the vertical clamping positioning nut hole 72 is slowly adjusted, and the wedge structure 512 of the reference cavity cylindrical tube 51 is used to deform the welding diaphragm 53, thereby further reducing the brazing temperature and affecting the capacitance measurement part inside the cylindrical tube on the strain of the welding diaphragm 53.

[0083] Furthermore, the middle of the welding diaphragm 53 is provided with an annular nickel-plated coating 531 and an annular nickel-plated coating 532 by a semi-coating method.

[0084] Furthermore, the reference cavity cylindrical tube is in the form of a sleeve, and an annular solder is provided in the middle of the sleeve, and the solder can be silver-copper solder.

[0085] Furthermore, the inner cylinder of the reference cavity cylindrical cylinder 54 is provided with a wedge-shaped structure 512 for increasing the pressing force of the diaphragm.

[0086] Furthermore, a positioning groove 55 is provided on the lower plane of the measuring cavity cylinder, and a wedge-shaped structure 542 for raising the height of the diaphragm is provided on the outer edge of the upper plane to prevent the annular solder from overflowing.

[0087] Furthermore, the reference cavity cylindrical wedge 512 is higher than the measuring cavity wedge 542 to maintain the pressing force of the wedge structure 512 of the reference cavity cylindrical 54 on the welding diaphragm 53 .

[0088] Furthermore, a groove is provided on the plane of the measuring cavity cylindrical barrel 54, and a brazing solder layer 541 is coated in the groove, and the solder can be silver-copper solder.

[0089] Furthermore, the middle annular nickel-plated coatings 531 and 532 of the welding diaphragm 53 are arranged in the middle position of the planar groove on the measuring cavity cylinder 51 to ensure the diaphragm welding area.

[0090] Furthermore, the inner cylinder wedge structure 512 of the reference cavity cylindrical cylinder 51, the planar wedge structure 542 on the measuring cavity cylindrical cylinder 54, and the planar groove on the measuring cavity cylindrical cylinder 54 form a directional melting zone of the solder.

[0091] Furthermore, after completing the sensor welding assembly 5, the three sets of horizontal tensions are reset to zero through the tension adjustment system 6, forming a horizontal stress free end of the diaphragm to ensure that the thermal stress generated by the diaphragm during the brazing process can be released to the free end and to ensure effective contact between the upper and lower solders, thereby further reducing the impact on the flatness of the diaphragm inside the welded sensor assembly 5 and the welding strength.

[0092] Furthermore, the horizontal tension adjustment system 6, the vertical pressure change sensing mechanism 3, the vertical pressure change stepping mechanism 7, the observation window 2, and the upper cover of the vacuum chamber 1 are provided with a water cooling circulation system.

[0093] Furthermore, the vacuum chamber 1 equipped with the sensor welding assembly 5 can be connected to the vacuum brazing system 12 in a ring array or other parallel forms to achieve batch brazing.

[0094] During batch brazing, the sensor welding components 5 to be brazed are respectively loaded into each vacuum chamber, and the oil-free molecular pump group provides a clean oil-free vacuum environment for the batch vacuum brazing system 12. During evacuation, the cold cathode composite vacuum gauge collects the pressure of each vacuum chamber. When the vacuum chamber pressure is better than 5E-3Pa, the heating system of each vacuum chamber is turned on. The thermocouples set in each vacuum chamber collect the chamber pressure in real time, and the industrial computer adjusts the heating power in real time through automatic feedback to keep the deviation between the temperature inside the chamber and the set temperature at ±3°C. The heating system realizes batch welding of the sensor welding components 5 according to the set brazing temperature curve.

[0095] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A welding device for a metal diaphragm for a capacitance thin film vacuum gauge, characterized in that: The welding device comprises a vacuum chamber, an observation window, a vertical pressure change sensing mechanism, a vertical pressure sensor, a sensor welding assembly, a horizontal tension regulator system, a vertical pressure change stepping mechanism, an infrared locator and a radiation heating screen; An observation window is provided on one side of the vacuum chamber for observing the interior of the vacuum chamber; A vertical pressure change sensing mechanism is provided at the bottom of the vacuum chamber; A vertical pressure sensor and a sensor welding assembly are installed on the vacuum chamber; There are three sets of horizontal tension adjustment systems around the circumference of the vacuum chamber; A vertical pressure-variable stepping mechanism is arranged on the upper part of the vacuum chamber.

2. The welding device for a metal diaphragm for a capacitance thin film vacuum gauge according to claim 1, characterized in that: The horizontal tension adjustment system, the vertical pressure change sensing mechanism and the vertical pressure change sensing mechanism provide horizontal tensile stress and vertical compressive stress for the diaphragm to be welded; The vacuum chamber provides vacuum pressure guarantee for vacuum brazing process; The observation window is used to adjust the state of the diaphragm horizontally and vertically; The radiation heating screen provides temperature guarantee for vacuum brazing; The vertical pressure change sensing mechanism on the bottom surface of the vacuum chamber and the vertical pressure change stepping mechanism on the vacuum chamber together constitute a diaphragm vertical pressure change regulating system.

3. The welding device for a metal diaphragm for a capacitance thin film vacuum gauge according to claim 1, characterized in that: The vertical pressure change sensing mechanism includes a vertical welded bellows and a compression spring; The sensor welding assembly includes a reference cavity cylindrical tube, annular solder, a welding diaphragm, a measuring cavity cylindrical tube, and a positioning groove; An annular solder placement groove and a wedge-shaped structure on the lower plane of the reference cavity are arranged in the reference cavity cylinder; The welding diaphragm is provided with a circular nickel-plated coating and a circular nickel-plated coating; The measuring cavity cylindrical tube is provided with a measuring cavity cylindrical tube and a wedge-shaped structure; The horizontal tension regulator system is equipped with a horizontal tension adjustment bolt, a horizontal tension positioning nut hole, a horizontal tension sensor, a horizontal compression spring, a horizontal compression spring mounting hole, a horizontal welding bellows, and a horizontal tension wire drawing fastening hole; The vertical compression stepping mechanism is provided with a vertical compression adjusting bolt, a vertical compression positioning nut hole, a vertical compression compression spring installation hole, and a vertical welding bellows; The bottom of the measuring cavity cylinder of the sensor welding assembly is placed on the upper plane of the vertical pressure change sensing mechanism, and then the welding diaphragm, the reference cavity cylinder and the annular solder are placed in sequence; After the positioning groove of the measuring cylindrical cavity is inserted into the upper flat boss of the vertical pressure-change sensing mechanism, the infrared positioning ring concentric with the infrared positioning instrument marked by the infrared positioning instrument is used as a reference standard to fine-tune the position of the cylindrical measuring cavity on the upper flat surface of the vertical pressure-change sensing mechanism to accurately determine the placement position of the measuring cavity cylindrical cylinder; Using the infrared locator positioning ring concentric with the infrared locator as a reference standard, fine-tune the position of the welding diaphragm in the measuring cavity cylinder to determine the placement position of the welding diaphragm; Using the infrared locator positioning ring concentric with the infrared locator as a reference standard, fine-tune the position of the reference cavity cylinder on the film to determine the placement position of the reference cavity cylinder; The determination and control of the horizontal tension of the diaphragm to be welded is provided by adjusting the three horizontal tension adjustment systems of the vacuum chamber, and the vertical pressure change of the diaphragm to be welded is achieved by the vertical pressure change adjustment system.

4. A welding device for a metal diaphragm for a capacitance thin film vacuum gauge according to claim 3, characterized in that: In the horizontal tension adjustment system, the displacement of the horizontal welding bellows is driven by adjusting the step amount of the horizontal tension adjustment bolt installed on the horizontal tension positioning nut hole.

5. The welding device for a metal diaphragm for a capacitance thin film vacuum gauge according to claim 3, characterized in that: The displacement of the horizontal welded bellows further drives the deformation of the horizontal compression spring, thereby generating a compression sensing force on the horizontal tension sensor in contact with it, and the horizontal tensile stress of the welded diaphragm in the triangular direction is precisely controlled through the compression sensing force.

6. A welding device for a metal diaphragm for a capacitance thin film vacuum gauge according to claim 2, characterized in that: The displacement of the vertical compression stepping mechanism on the upper part of the vacuum chamber is achieved by driving the vertical welding bellows to move by the stepping of the vertical compression adjusting bolt; The displacement of the vertical pressure-variable stepping mechanism further drives the compression spring inside the vertical pressure-variable sensing mechanism to obtain the sensing force of the welding diaphragm in the vertical direction.

7. A welding device for a metal diaphragm for a capacitance thin film vacuum gauge according to claim 2, characterized in that: The displacement zero point of the vertical pressure-variable stepping mechanism is based on the contact resistance between the vertical pressure-variable sensing mechanism and the vertical pressure-variable stepping mechanism. When the resistance between the vertical pressure-variable sensing mechanism and the vertical pressure-variable stepping mechanism changes from infinity to ohm level, it is used as the adjustment origin of the vertical pressure-variable stepping mechanism. The welding diaphragm is an equilateral triangle structure. The diaphragm triangle is connected to three sets of horizontal tension adjustment systems through wire drawing. The vertical adjustment bolt on the vertical compression positioning nut hole is slowly adjusted. The wedge-shaped structure of the reference cavity cylinder makes the welding diaphragm deform, and the brazing temperature is further reduced to affect the capacitance measurement part inside the cylinder on the strain of the welding diaphragm.

8. The welding device for a metal diaphragm for a capacitance thin film vacuum gauge according to claim 2, characterized in that: A circular nickel-plated coating and a circular nickel-plated coating are provided in the middle of the welding diaphragm by means of semi-coating; The reference cavity cylinder is in the form of a sleeve, and a ring solder is arranged in the middle of the sleeve, and the solder is selected as silver-copper solder; The inner cylinder of the reference cavity cylindrical cylinder is provided with a wedge-shaped structure for increasing the pressing force of the diaphragm; A positioning groove is provided on the lower plane of the measuring cavity cylinder, and a wedge-shaped structure for raising the height of the diaphragm is provided on the outer edge of the upper plane to prevent the annular solder from overflowing; The wedge shape of the reference cavity cylinder is higher than the wedge shape of the measuring cavity, so as to maintain the pressing force of the wedge structure of the reference cavity cylinder on the welding diaphragm; A groove is provided on the plane of the cylindrical barrel of the measuring cavity, and a brazing solder layer is coated in the groove, and the solder is selected as silver-copper solder; The middle annular nickel-plated coating of the welding diaphragm is arranged in the middle position of the plane groove on the cylindrical tube of the measuring cavity to ensure the welding interval of the diaphragm; The inner cylinder wedge structure of the reference cavity cylinder, the plane wedge structure on the measuring cavity cylinder and the plane groove on the measuring cavity cylinder form a directional melting zone of the solder.

9. A welding device for a metal diaphragm for a capacitance thin film vacuum gauge according to claim 8, characterized in that: The three sets of horizontal tension are adjusted to zero by adjusting the system tension to form a horizontal stress free end of the diaphragm to ensure that the thermal stress generated by the diaphragm during the brazing process can be released to the free end and to ensure effective contact between the upper and lower solders, further reducing the impact on the flatness of the diaphragm inside the welded sensor assembly and the welding strength.

10. The welding device for a metal diaphragm for a capacitance thin film vacuum gauge according to claim 1, characterized in that: The horizontal tension adjustment system, vertical pressure change sensing mechanism, vertical pressure change stepping mechanism, observation window, and vacuum chamber upper cover are equipped with a water cooling circulation system; the vacuum chamber equipped with sensor welding components forms a ring array connected to the vacuum brazing system to realize batch brazing.

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