Positioning brazing structure of single-needle lead insulator and preparation method

Abstract

The invention provides a positioning brazing structure of a single-pin lead insulator and a preparation method, the positioning brazing structure is used for positioning brazing of the single-pin lead insulator, and comprises a Dewar shell and a positioning lantern ring; the Dewar shell is of a cylindrical structure, a preformed hole is formed in the center of the Dewar shell, and the positioning lantern ring is sleeved with the preformed hole in a penetrating mode; the positioning lantern ring adopts a cylindrical structure and is sleeved in the preformed hole in a penetrating manner, and a positioning lantern ring inner hole is formed in the center of the positioning lantern ring and is used for penetrating and sleeving an insulator; the insulator is sleeved in an inner hole of the positioning lantern ring in a penetrating manner; high-reliability airtight welding between the insulator and the positioning lantern ring and between the positioning lantern ring and the Dewar shell is achieved in a low-temperature brazing mode. Through the innovatively designed positioning lantern ring and accurate gap control, the welding yield of the insulator and the Dewar shell is remarkably improved, high air tightness and mechanical strength in the welding process are ensured, the production cost is reduced, and the assembly quality and the use reliability are improved.

Description

Technical Field

[0001] The invention relates to a dewar packaging technology for an infrared detector component, in particular to a positioning brazing structure of a single-needle lead insulator and a preparation method thereof. Background Art

[0002] Infrared detector components have the advantages of high sensitivity, fast response speed, and long detector distance. They are widely used in civil fields such as aerospace, and are specifically widely used in infrared remote sensing, civil security, etc. Usually, infrared detectors need to work at low temperatures (about 80K), and they are generally packaged and prepared using a component Dewar structure. While providing optical, mechanical, electrical, and thermal interfaces for infrared detectors, the Dewar also has the function of providing mechanical protection and a vacuum environment for infrared detectors. Therefore, the preparation technology of infrared detector component Dewar is of great significance in the aerospace and aviation infrared fields.

[0003] In order to ensure the structural strength of the dewar, metal materials are generally used to prepare the dewar. The preparation of the component dewar consists of infrared detectors, core columns, cold heads, shells, porcelain rings, window caps and other components. In order to improve the vacuum life of the infrared detector component dewar, in general, the shell of the dewar needs to be brazed with a single-pin insulator to install the getter. In order to improve the yield of the brazed insulator to meet the requirements of leakage rate, a single-pin lead insulator positioning brazing structure is urgently needed to ensure the reliability of the insulator. Summary of the invention

[0004] The object of the present invention is to provide a positioning ring, which can effectively solve the problem of low welding yield rate caused by machining errors of the insulator and machining errors of reserved holes on the dewar shell, and a positioning brazing structure and a preparation method for a single-needle lead insulator.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A positioning brazing structure for a single-needle lead insulator is used for positioning brazing the single-needle lead insulator, comprising a dewar shell and a positioning collar; the dewar shell adopts a cylindrical structure, a reserved hole is provided at the center of the dewar shell, and the reserved hole is used to insert the positioning collar; the positioning collar adopts a cylindrical structure, is inserted into the reserved hole, a positioning collar inner hole is provided at the center of the positioning collar, and is used to insert the insulator; the insulator is inserted into the positioning collar inner hole; the insulator and the positioning collar, and the positioning collar and the dewar shell are welded with high reliability through low-temperature brazing.

[0007] Preferably, the aperture of the reserved hole is 0.02 mm to 0.05 mm larger than the outer diameter of the positioning collar, so as to ensure that the positioning collar can be smoothly installed in the Dewar shell and has an appropriate gap, thereby facilitating the flow and distribution of solder in the subsequent brazing process, and the gap can ensure that during brazing, the solder can fully cover the contact surface and effectively fill the gap between the Dewar shell and the positioning collar, ensuring high-reliability airtight welding.

[0008] Preferably, the diameter of the inner hole of the positioning ring is 0.02mm to 0.05mm larger than the outer diameter of the insulator, so as to ensure that the insulator can be smoothly inserted into the inner hole of the positioning ring and retain an appropriate gap during the installation process; the gap helps the solder to flow evenly during the brazing process and fill the joint surface between the insulator and the positioning ring, thereby achieving high-strength and high-airtightness welding, while ensuring the precise positioning and stability of the insulator in the positioning ring.

[0009] Preferably, flanges are provided on both sides of one end of the positioning collar, and the flanges are used to support and fix with the Dewar shell to improve the installation stability of the positioning collar in the Dewar shell. The flanges can provide additional support during the installation process to prevent the positioning collar from axial movement or offset, and at the same time provide a reliable structural basis for the brazing process, further ensuring the firmness and airtightness of the overall assembly.

[0010] Preferably, the insulator includes a single needle, a sleeve ring and an outer sleeve ring from the inside to the outside, and the single needle, the sleeve ring and the outer sleeve ring are sintered into an integrated structure at high temperature to ensure that the insulator has excellent mechanical strength and air tightness under high temperature, high pressure and low temperature environments;

[0011] The single needle is made of Kovar material to provide electrical connection function;

[0012] The sleeve ring is made of ceramic material and has good insulation performance;

[0013] The outer sleeve ring is made of kovar material to provide overall structural support and brazing interface, so that the insulator can operate stably and maintain reliable performance in a complex working environment.

[0014] The present invention also provides a method for preparing a positioning brazing structure of a single-needle lead-in insulator, which is characterized by comprising the following steps:

[0015] Step S1: Installation of the locating ring

[0016] First, prepare the positioning collar and ensure that its size is consistent with the reserved hole of the dewar shell; the positioning collar is prepared to have an inner and outer ring structure so as to accurately fix the insulator in the dewar shell;

[0017] Nest the positioning collar into the reserved hole on the Dewar shell, and ensure that the positioning collar and the Dewar shell fit tightly without looseness or deviation, forming a positioning basis;

[0018] Step S2: Place insulators

[0019] Prepare a single-needle lead insulator and place it firmly in the inner hole of the positioning collar, making sure that the lead end faces outward and the contact surface between the insulating part and the inner hole of the collar is good and error-free, so as to facilitate subsequent welding;

[0020] Step S3: Laying the first layer of silver-copper solder

[0021] Place a ring of silver-copper solder over the gap between the Dewar shell and the locating collar;

[0022] The silver-copper solder is evenly laid in the gap between the Dewar shell and the positioning collar to ensure that the silver-copper solder can provide good bonding force and promote air tightness and mechanical strength during subsequent brazing;

[0023] Step S4: Place the second layer of silver-copper solder

[0024] Gently place a ring of silver-copper solder again above the gap between the positioning ring and the insulator; ensure that the silver-copper solder can provide good bonding force to promote air tightness and mechanical strength during subsequent brazing;

[0025] Step S5: Perform brazing operation

[0026] After all parts are prepared, the final connection is made through a low-temperature brazing process;

[0027] The soldering assembly is first heated to the appropriate temperature, usually using an electronic or laser heating system, to ensure that the solder melts and flows into the joint;

[0028] During the heating process, the silver-copper solder will flow between the Dewar shell and the positioning collar, and between the positioning collar and the insulator, filling the gap and ensuring a tight fit between the two interfaces;

[0029] By precisely controlling the temperature, heating time and cooling speed, a high-reliability and airtight single-needle lead insulator positioning brazing assembly process is ultimately formed, achieving high-reliability and airtight welding between the single-needle lead insulator and the Dewar housing.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The present invention has a simple structure, convenient operation and low price: The present invention adopts a simple and effective structural design, reduces complex processing steps and high precision requirements, thereby reducing production costs. At the same time, the operation process is simple, suitable for large-scale production and application, and has high production efficiency.

[0032] (2) The present invention is compatible with processing errors and solves the problem of being unable to be directly welded to the shell: Since the insulator may have dimensional errors during the processing process, it is impossible to directly weld it to the dewar shell. The positioning ring designed by the present invention and the precise gap control can effectively compensate for this error, ensuring that the insulator and the dewar shell can be brazed smoothly, solving the problem of being unable to weld due to processing errors.

[0033] (3) The present invention improves the welding yield rate and ensures high reliability: Through the structural design and welding process of the present invention, the welding yield rate of the insulator and the dewar shell can be greatly improved. The precise control of the positioning ring and the gap ensures the airtightness and mechanical strength during the welding process, thereby effectively reducing the product failure rate caused by poor welding and improving the reliability and quality of the overall assembly.

[0034] In summary, the present invention has a simple structure, convenient operation, and low price. Through the innovatively designed positioning ring and precise gap control, the problem of inability to directly weld due to insulator processing errors is effectively solved, and the welding yield of insulators and dewar shells is significantly improved. This design is not only compatible with processing errors, ensuring high air tightness and mechanical strength during the welding process, but also reduces production costs, improves assembly quality and reliability, is suitable for large-scale applications, and has a wide range of practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic structural diagram of a Dewar housing, a positioning collar and an insulator assembly in a positioning brazing structure of a single-needle lead-in insulator provided by an embodiment of the present invention;

[0036] Figure 2 A schematic structural diagram of a Dewar housing in a positioning brazing structure of a single-needle lead-in insulator provided by an embodiment of the present invention;

[0037] Figure 3 A schematic front view of the structure of a positioning ring in a positioning brazing structure of a single-needle lead-in insulator provided by an embodiment of the present invention;

[0038] Figure 4 A schematic top view of a positioning ring in a positioning brazing structure of a single-needle lead-in insulator provided by an embodiment of the present invention;

[0039] Figure 5 A schematic diagram of the front view structure of an insulator in a positioning brazing structure of a single-needle lead-in insulator provided by an embodiment of the present invention;

[0040] Figure 6 A schematic diagram of the top view of the insulator in a positioning brazing structure of a single-needle lead insulator provided by an embodiment of the present invention.

[0041] The serial numbers in the figure are as follows:

[0042] 1. Dewar housing; 101. reserved hole; 2. positioning collar; 201. flange of positioning collar; 202. outer diameter of positioning collar; 203. inner hole of positioning collar; 3. insulator; 301. outer diameter of insulator; 3. insulator; 301. outer diameter of insulator; 302. external collar; 303. collar; 304. single needle. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0044] like Figures 1 to 6 As shown, a positioning brazing structure of a single-pin lead insulator provided in this embodiment is used for positioning brazing a single-pin lead insulator 3 , and includes a Dewar housing 1 and a positioning collar 2 .

[0045] The Dewar shell 1 is a cylindrical structure, made of Kovar, and is machined. The cylinder wall thickness is 1mm. The diameter of the reserved hole 101 of the Dewar shell 1 is 4mm, and the tolerance is ±0.05mm. A reserved hole 101 is provided in the center of the Dewar shell 1, and the reserved hole 101 is used to insert the positioning collar 2;

[0046] The positioning ring 2 adopts a cylindrical structure and is inserted into the reserved hole 101. The center of the positioning ring 2 is provided with a positioning ring inner hole 203 for inserting the insulator 3. The positioning ring 2 is made of calcified material and is prepared by machining. The diameter of the positioning ring 2 is 3.78mm, the wall thickness is 0.3mm, and the distance between the supporting surfaces on both sides is 4.30mm. The positioning ring 2 can be placed in the brazing aperture of the Dewar shell and installed and fixed.

[0047] The insulator 3 is inserted into the inner hole 203 of the positioning collar; the insulator 3 includes a single needle 304, a collar 303 and an outer collar 302 from the inside to the outside, and the single needle 304, the collar 303 and the outer collar 302 are sintered into an integrated structure at high temperature to ensure that the insulator 3 has excellent mechanical strength and air tightness under high temperature, high pressure and low temperature environments; the single needle 304 is made of Kovar material to provide electrical connection function; the collar 303 is made of ceramic wrapped with a Kovar thin layer and is cylindrical in shape, and has good insulation performance;

[0048] The outer diameter 301 of the insulator is 3.12 mm, the machining error is ±0.02 mm, the outer diameter of the single pin 304 is 1 mm, and the length of the insulator 3 is 10 mm.

[0049] The outer sleeve ring 302 is made of kovar material to provide overall structural support and a brazing interface, so that the insulator 3 can operate stably and maintain reliable performance in a complex working environment.

[0050] The insulator 3 and the positioning collar 2 as well as the positioning collar 2 and the Dewar housing 1 are welded in a low-temperature brazing manner to achieve high-reliability airtight welding.

[0051] The inner diameter of the inner hole 203 of the positioning collar is 3.20mm, and the positive tolerance is 0.01mm to 0.03mm. The flange 201 of the positioning collar has a width of 0.5mm, a distance between the two support surfaces of 4.30mm, and an outer diameter 202 of the positioning collar is 3.78mm, and the tolerance is a negative tolerance of 0.03mm to 0.01mm.

[0052] Furthermore, in the present embodiment, the aperture of the reserved hole 101 is 0.02 mm to 0.05 mm larger than the outer diameter 202 of the positioning collar 2, so as to ensure that the positioning collar 2 can be smoothly installed in the Dewar housing 1 and has an appropriate gap, thereby facilitating the flow and distribution of the solder in the subsequent brazing process, and the gap can ensure that during brazing, the solder can fully cover the contact surface and effectively fill the gap between the Dewar housing and the positioning collar, thereby ensuring high-reliability airtight welding.

[0053] Preferably, the diameter of the inner hole 203 of the positioning collar is 0.02 mm to 0.05 mm larger than the outer diameter 301 of the insulator 3, so as to ensure that the insulator 3 can be smoothly inserted into the inner hole 203 of the positioning collar 2 and retain an appropriate gap during the installation process; the gap helps the solder to flow evenly during the brazing process and fill the joint surface between the insulator and the positioning collar, thereby achieving high-strength and high-airtightness welding, while ensuring the precise positioning and stability of the insulator in the positioning collar.

[0054] Further, in this embodiment, flanges 201 are provided on both sides of one end of the positioning collar 2, and the flanges 201 are used to support and fix with the Dewar shell 1 to improve the installation stability of the positioning collar in the Dewar shell. The flanges 201 can provide additional support during the installation process to prevent the positioning collar from axial movement or offset, and at the same time provide a reliable structural foundation for the brazing process, further ensuring the firmness and airtightness of the overall assembly.

[0055] The present invention also provides a method for preparing a positioning brazing structure of a single-needle lead-in insulator, which is characterized by comprising the following steps:

[0056] Step S1: Installation of the locating ring

[0057] First, prepare the positioning collar 2 and ensure that its size is consistent with the reserved hole 101 of the Dewar housing 1; the positioning collar 2 is prepared to have an inner and outer ring structure so as to accurately fix the insulator 3 in the Dewar housing 1;

[0058] Nest the positioning collar 2 in the reserved hole 101 on the Dewar housing 1, and ensure that the positioning collar 2 and the Dewar housing 1 fit tightly without looseness or deviation, forming a positioning basis;

[0059] Step S2: Place insulators

[0060] Prepare a single-needle lead insulator 3, and place the insulator 3 firmly in the inner hole 203 of the positioning collar 2, ensuring that the lead end faces outwards and the contact surface between the insulating part and the inner hole of the collar is good and error-free, so as to facilitate subsequent welding;

[0061] Step S3: Laying the first layer of silver-copper solder

[0062] A ring of silver-copper solder is placed above the gap between the Dewar shell 1 and the positioning collar 2. The silver-copper solder is selected to have a lower melting point and excellent welding performance.

[0063] The silver-copper solder is evenly laid in the gap between the Dewar shell 1 and the positioning collar 2 to ensure that the silver-copper solder can provide good bonding force and promote air tightness and mechanical strength during subsequent brazing;

[0064] Step S4: Place the second layer of silver-copper solder

[0065] Gently place a ring of silver-copper solder again above the gap between the positioning ring 2 and the insulator 3; ensure that the silver-copper solder can provide good bonding force to promote air tightness and mechanical strength during subsequent brazing;

[0066] Step S5: Perform brazing operation

[0067] After all parts are prepared, the final connection is made through a low-temperature brazing process;

[0068] The soldering assembly is first heated to the appropriate temperature, usually using an electronic or laser heating system, to ensure that the solder melts and flows into the joint;

[0069] During the heating process, the silver-copper solder will flow between the Dewar shell 1 and the positioning collar 2, and between the positioning collar 2 and the insulator 3, filling the gap and ensuring the tight connection of the two interfaces;

[0070] By precisely controlling the temperature, heating time and cooling speed, a high-reliability and airtight single-needle lead insulator positioning brazing assembly process is finally formed, thereby achieving high-reliability and airtight welding between the single-needle lead insulator 3 and the Dewar housing 1.

[0071] The invention has a simple structure, convenient operation and low price. Through the innovatively designed positioning ring and precise gap control, the problem of inability to directly weld due to insulator processing errors is effectively solved, and the welding yield of insulators and dewar shells is significantly improved. The design is not only compatible with processing errors, ensuring high air tightness and mechanical strength during the welding process, but also reduces production costs, improves assembly quality and reliability, is suitable for large-scale applications, and has wide practical value.

[0072] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0073] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0074] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A positioning brazing structure for a single-needle lead-in insulator, used for positioning brazing a single-needle lead-in insulator (3), characterized in that: It comprises a Dewar housing (1) and a positioning collar (2); The Dewar housing (1) adopts a cylindrical structure, and a reserved hole (101) is provided at the center of the Dewar housing (1), and the reserved hole (101) is used to pass the positioning ring (2); The positioning collar (2) has a cylindrical structure and is inserted into the reserved hole (101). A positioning collar inner hole (203) is provided at the center of the positioning collar (2) for inserting the insulator (3). The insulator (3) is inserted into the inner hole (203) of the positioning ring; The insulator (3) and the positioning collar (2), as well as the positioning collar (2) and the Dewar housing (1) are welded together in a manner of low-temperature brazing to achieve high-reliability airtight welding.

2. The positioning brazing structure of a single-needle lead insulator according to claim 1, characterized in that: The diameter of the reserved hole (101) is 0.02 mm to 0.05 mm larger than the outer diameter (202) of the positioning collar (2), so as to ensure that the positioning collar (2) can be smoothly installed in the Dewar housing (1) and has an appropriate gap, thereby facilitating the flow and distribution of solder during the subsequent brazing process. The gap can ensure that during brazing, the solder can fully cover the contact surface and effectively fill the gap between the Dewar housing and the positioning collar, thereby ensuring high-reliability airtight welding.

3. The positioning brazing structure of a single-needle lead insulator according to claim 1, characterized in that: The diameter of the inner hole (203) of the positioning collar is 0.02 mm to 0.05 mm larger than the outer diameter (301) of the insulator (3), so as to ensure that the insulator (3) can be smoothly inserted into the inner hole (203) of the positioning collar (2) and retain an appropriate gap during the installation process; the gap helps the solder to flow evenly during the brazing process and fill the joint surface between the insulator and the positioning collar, thereby achieving high-strength and high-airtightness welding, while ensuring the precise positioning and stability of the insulator in the positioning collar.

4. The positioning brazing structure of a single-needle lead insulator according to claim 1, characterized in that: Flanges (201) are respectively provided on both sides of one end of the positioning collar (2), and the flanges (201) are used to support and fix with the Dewar shell (1) to improve the installation stability of the positioning collar in the Dewar shell; the flanges (201) can provide additional support during the installation process to prevent the positioning collar from axial movement or offset, and at the same time provide a reliable structural basis for the brazing process, further ensuring the firmness and airtightness of the overall assembly.

5. The positioning brazing structure of a single-needle lead insulator according to claim 1, characterized in that: The insulator (3) comprises, from the inside to the outside, a single needle (304), a sleeve ring (303) and an external sleeve ring (302), wherein the single needle (304), the sleeve ring (303) and the external sleeve ring (302) are sintered at high temperature into an integrated structure, so as to ensure that the insulator (3) has excellent mechanical strength and air tightness in high temperature, high pressure and low temperature environments; The single needle (304) is made of varable material to provide an electrical connection function; The sleeve ring (303) is made of ceramic material and has good insulation performance; The outer sleeve ring (302) is made of varable material and is used to provide overall structural support and a brazing interface, so that the insulator (3) can operate stably and maintain reliable performance in a complex working environment.

6. A method for preparing a positioning brazing structure of a single-needle lead-in insulator according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step S1: Installation of the locating ring First, prepare the positioning collar (2) and ensure that its size is consistent with the reserved hole (101) of the Dewar housing (1); The positioning collar (2) is prepared to have an inner and outer ring structure so as to accurately fix the insulator (3) in the Dewar housing (1); The positioning collar (2) is nested in the reserved hole (101) on the Dewar housing (1), and it is ensured that the positioning collar (2) and the Dewar housing (1) are tightly matched without looseness or deviation, so as to form a positioning basis; Step S2: Place insulators Prepare a single-needle lead insulator (3), and place the insulator (3) firmly in the inner hole (203) of the positioning ring (2), ensuring that the lead end faces outwards and the contact surface between the insulating part and the inner hole of the ring is good and error-free, so as to facilitate subsequent welding; Step S3: Placing silver-copper solder (first layer) A ring of silver-copper solder is placed above the gap between the Dewar housing (1) and the positioning collar (2); The silver-copper solder is evenly laid in the gap between the Dewar shell (1) and the positioning ring (2), ensuring that the silver-copper solder can provide good bonding force and promote air tightness and mechanical strength during subsequent brazing; Step S4: Placing silver-copper solder (second layer) Gently place a ring of silver-copper solder again above the gap between the positioning ring (2) and the insulator (3); ensure that the silver-copper solder can provide good bonding force to promote air tightness and mechanical strength during subsequent brazing; Step S5: Perform brazing operation After all parts are prepared, the final connection is made through a low-temperature brazing process; The soldering assembly is first heated to the appropriate temperature, usually using an electronic or laser heating system, to ensure that the solder melts and flows into the joint; During the heating process, the silver-copper solder will flow between the Dewar shell (1) and the positioning collar (2), and between the positioning collar (2) and the insulator (3), filling the gap and ensuring the tight connection of the two interfaces; By precisely controlling the temperature, heating time and cooling speed, a high-reliability airtight single-needle lead insulator positioning brazing assembly process is finally formed, thereby achieving high-reliability airtight welding of the single-needle lead insulator (3) and the dewar housing (1).

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