Feedthrough assembly for a gas analyzer, brazing jig and method of manufacturing thereof

Abstract

This invention provides a feedthrough assembly for a gas analyzer, a brazing fixture, and a method for fabricating the same. The feedthrough assembly includes a stainless steel base with mounting holes, the stainless steel base being used to seal and connect to the sensor body on the gas analyzer; a stainless steel carrier, installed in the mounting holes and sealed to the stainless steel base, the stainless steel carrier having through holes; and a vacuum electrode assembly corresponding to and passing through the through holes, used to conduct electrical signals from the gas analyzer to the outside. This invention, by using a stainless steel base and a stainless steel carrier to fabricate the feedthrough assembly, fundamentally eliminates interference from the internal electric field of the ferromagnetic material gas analyzer, thereby ensuring the accuracy of ion trajectories, significantly improving the signal-to-noise ratio, sensitivity, and measurement accuracy of the gas analyzer, and thus improving the accuracy of the analytical results.

Description

Technical Field

[0001] This invention relates to the field of semiconductor device technology, and in particular to the feedthrough components, brazing fixtures, and their preparation methods for a gas analyzer. Background Technology

[0002] In semiconductor manufacturing processes, critical steps such as atomic layer deposition (ALD), physical vapor deposition (PVD), chemical vapor deposition (CVD), and dry etching all require strict vacuum conditions. During these processes, a gas analyzer serves as a core device, providing real-time online monitoring of gas composition, leaks, and trace contaminants within the vacuum chamber to ensure process stability and improve product yield. The gas analyzer is typically installed within the process chamber via its vacuum feedthrough assembly. This assembly is a critical interface penetrating the vacuum chamber wall, internally connecting to the sensor detection unit located on the vacuum side, and externally connecting to the control circuitry, signal processing module, and power supply system located in the atmospheric environment. Therefore, the insulation strength, sealing performance, and connection reliability of the vacuum feedthrough directly determine the overall performance of the gas analyzer.

[0003] In existing technologies, vacuum feedthrough bases are generally made of high-purity alumina (Al2O3) or similar ceramic materials, utilizing their excellent high-temperature stability, high resistivity, and good mechanical strength. The metal leads on the ceramic base are then connected via a high-temperature active metal brazing process. However, despite efforts to match materials as closely as possible, a slight difference in the coefficient of thermal expansion (CTE) still exists between the ceramic and the sealing metal. For example, during high-temperature brazing, the two materials interact due to their different thermal expansion rates; in the subsequent cooling and solidification stage, this interaction force cannot be fully released due to CTE mismatch, resulting in significant residual stress in the solder layer and the ceramic / metal interface region. This leads to a risk of microcracks or poor sealing at the weld joint. In vacuum environments requiring extremely high airtightness, even a tiny leak can affect the vacuum level, leading to inaccurate analytical results. Summary of the Invention

[0004] The purpose of this invention is to provide a feedthrough assembly, brazing fixture and its preparation method for a gas analyzer, which ensures the sealing of the gas analyzer's external connections, thereby ensuring the reliability of the gas analyzer.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a feedthrough assembly for a gas analyzer, comprising:

[0006] A stainless steel base with mounting holes is used to seal and connect to the sensor body on the gas analyzer.

[0007] A stainless steel support component is installed in the mounting hole and is sealed to the stainless steel base; the stainless steel support component has a through hole.

[0008] A vacuum electrode assembly, corresponding to and passing through the through hole, is used to transmit electrical signals from the gas analyzer to the outside.

[0009] In some embodiments, the through hole includes a central through hole and a plurality of edge through holes located around the central through hole, the plurality of edge through holes being arranged at circumferential intervals;

[0010] The vacuum electrode assembly includes a central electrode assembly and several edge electrode assemblies. The central electrode assembly passes through the central through hole and is sealed to the stainless steel carrier. Each edge electrode assembly passes through the corresponding edge through hole and is sealed to the stainless steel carrier.

[0011] In some embodiments, both the central electrode assembly and the edge electrode assembly include a cap ring, a ceramic pillar, a transition member, and an electrode rod;

[0012] The ceramic column has a through hole that passes through it along the axis of the ceramic column;

[0013] The transition piece is fitted onto the ceramic column and is used to seal the connection between the ceramic column and the stainless steel support piece.

[0014] The electrode rod passes through the through hole and is used to conduct electrical signals;

[0015] The cap ring is connected to the top of the ceramic column and sleeved on the electrode rod to seal one end of the through hole.

[0016] In some embodiments, the ceramic column is made of alumina ceramic, and the welding areas of the ceramic column all have a metal layer.

[0017] The cap ring is welded to the welding area at the top of the ceramic column;

[0018] The inner wall of the transition piece is welded to the welding area of ​​the outer wall of the ceramic column, and the outer wall of the transition piece is welded to the stainless steel support.

[0019] In some embodiments, the transition member is a ring-shaped structure made of Kovar alloy, and the transition member is interference-fitted with and welded to both the central through hole and the edge through hole; and / or,

[0020] The surfaces of the stainless steel support, the electrode rod, the transition piece, and the cover ring are all nickel-plated to form a coating.

[0021] In some embodiments, the metal layer includes a molybdenum-manganese layer and a nickel layer;

[0022] The molybdenum-manganese layer and the nickel layer are sequentially disposed in the welding area of ​​the ceramic column.

[0023] Secondly, this application provides a brazing fixture for fabricating the feedthrough assembly, the brazing fixture comprising:

[0024] The mounting base has a protrusion adapted to the mounting hole, and a positioning hole is provided on the protrusion corresponding to the through hole on the stainless steel support member. The positioning hole is used for pre-installing the vacuum electrode assembly.

[0025] The fixing block has a limiting boss corresponding to the positioning hole. The limiting boss is adapted to the through hole, and the side wall of the limiting boss has a slot for venting. The center of the limiting boss has a receiving hole for accommodating the vacuum electrode assembly.

[0026] In the working state, the vacuum electrode assembly is inserted into the positioning hole, the stainless steel carrier and the stainless steel base are connected and installed on the protrusion, and the fixing block passes through the mounting hole and abuts against the stainless steel carrier.

[0027] Thirdly, this application provides a method for fabricating a feedthrough component, wherein the feedthrough component is fabricated using the aforementioned brazing fixture, and the fabrication method includes:

[0028] After cleaning the surfaces of the stainless steel bearing components, electrode rods, transition components, and cap rings to be welded, nickel plating is performed.

[0029] The welding area of ​​the ceramic column is metallized to form a metal layer;

[0030] The stainless steel bearing component is assembled with the stainless steel base and then welded to form a welded component.

[0031] The transition piece is cryogenically treated in a liquid nitrogen environment and then installed on the corresponding position on the stainless steel carrier to form an interference fit.

[0032] Insert the electrode rods into the positioning holes on the mounting base respectively;

[0033] The welded component, the ceramic column, and the cover ring are sequentially fitted onto the corresponding electrode rods; wherein, the cover ring, the ceramic column, the transition component, and the electrode rods are combined to form the vacuum electrode assembly;

[0034] The fixing block is installed in the mounting hole of the stainless steel base and abuts against the stainless steel bearing to form an assembly;

[0035] A copper-based solder sheet is placed between the ceramic pillar and the electrode rod, between the ceramic pillar and the transition piece, and between the transition piece and the stainless steel support piece.

[0036] The assembly is moved into a high-temperature brazing furnace, and the temperature is controlled within the range of 820~850℃. The assembly is held at this temperature for 5~15 minutes to complete the welding.

[0037] After welding, the temperature is controlled to be cooled from 800℃ to 500℃ at a cooling rate not exceeding 2℃ / min, and then cooled from 500℃ to 300℃ at a cooling rate of 3-5℃ / min, and then cooled to room temperature.

[0038] In some embodiments, after cleaning the surfaces of the stainless steel carrier, electrode rod, transition piece, and cap ring to be welded, nickel plating is performed, including:

[0039] The stainless steel support, the electrode rod, the transition piece, and the cover ring are plated with a nickel layer of 3-8 μm thickness on the surfaces to be welded.

[0040] In some embodiments, the surface of the ceramic column to be welded is metallized to form a metal layer, including:

[0041] A molybdenum-manganese layer with a thickness of 15-35 μm is first plated on the surface of the ceramic column to be welded, followed by a nickel layer with a thickness of 3-8 μm.

[0042] The beneficial effects of the feedthrough assembly, brazing fixture, and preparation method of the gas analyzer provided by this invention are as follows:

[0043] 1. By using a stainless steel base and stainless steel bearing components, the interference of the internal electric field of the ferromagnetic material gas analyzer is fundamentally eliminated, thereby ensuring the accuracy of ion trajectory and significantly improving the signal-to-noise ratio, sensitivity, and measurement accuracy of the gas analyzer, thus improving the accuracy of the analysis results.

[0044] 2. The brazing between the stainless steel base and the stainless steel load-bearing component is a metal-to-metal connection with a perfect match in thermal expansion coefficients and minimal residual welding stress. This fundamentally avoids the risk of micro-cracks and leaks caused by thermal stress, greatly improving the airtightness of the feedthrough component.

[0045] 3. By setting a transition piece and forming a metal layer in the welding area of ​​the ceramic column, the stress caused by the difference in thermal expansion coefficient between the ceramic column and the stainless steel load-bearing component is effectively buffered, further enhancing the reliability of the weld under thermal cycling.

[0046] 4. By adopting liquid nitrogen cold fitting interference fit technology, the transition part and the stainless steel load-bearing part are interference fitted and then welded, which realizes pre-tightening at room temperature and stress release at high temperature, dynamically optimizes the stress distribution at the interface of dissimilar materials, and significantly improves the thermal fatigue resistance.

[0047] 5. By controlling the brazing temperature at 820-850℃, incomplete welds and leaks are eliminated. Furthermore, a slow cooling process (cooling from 800℃ to 500℃ at a rate not exceeding 2℃ / min, and from 500℃ to 300℃ at a controlled cooling rate of 3-5℃ / min) minimizes residual welding stress. These two processes together ensure the weld quality and long-term reliability.

[0048] 6. The ceramic pillar, stainless steel support, electrode rod, transition piece and cap ring have undergone targeted metallization treatment, which greatly improves the wettability and bonding strength of the brazing filler metal.

[0049] 7. The use of a stainless steel base and stainless steel bearing components significantly reduces raw material costs. Furthermore, the simplified structure of the stainless steel base and bearing components reduces tooling complexity and process control difficulty, thereby improving production efficiency and yield. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the feedthrough component from a first-view perspective, provided by an embodiment of the present invention;

[0051] Figure 2 This is a schematic diagram of the feedthrough component from a second perspective, provided in an embodiment of the present invention.

[0052] Figure 3 A perspective view of the stainless steel bearing component provided in the embodiments of the present invention;

[0053] Figure 4 A cross-sectional view along the axial direction of a stainless steel bearing member provided in an embodiment of the present invention;

[0054] Figure 5 An exploded view of the vacuum electrode assembly provided in an embodiment of the present invention;

[0055] Figure 6 A perspective view of the fixing block provided in an embodiment of the present invention;

[0056] Figure 7 A cross-sectional view of the fixing block along its axial direction, provided in an embodiment of the present invention;

[0057] Figure 8 A schematic diagram of the feedthrough assembly using brazing fixtures provided in the embodiments of the present invention;

[0058] Figure 9 A cross-sectional view along the axial direction of the feedthrough assembly after it has been assembled using a brazing fixture, as provided in the embodiment of the present invention;

[0059] Figure 10 A flowchart illustrating the fabrication method of the feedthrough component according to an embodiment of the present invention.

[0060] Figure label:

[0061] 1. Stainless steel base; 2. Stainless steel bearing component; 2. Through hole; 21. Center through hole; 211. Edge through hole; 212. Edge boss; 213. Vacuum electrode assembly; 3. Cover ring; 31. Ceramic column; 32. Transition component; 33. Electrode rod; 34. Fixing seat; 4. Protrusion; 41. Positioning hole; 42. Fixing block; 5. Limiting boss; 51. Groove; 52. Receiving hole; 53. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.

[0063] This invention provides a feedthrough component for a gas analyzer, with reference to... Figures 1 to 4 As shown, the feedthrough assembly includes a stainless steel base 1, a stainless steel support 2, and a vacuum electrode assembly 3. The stainless steel base 1 has a mounting hole and is used for sealingly connecting to the sensor body on the gas analyzer. The stainless steel support 2 is installed in the mounting hole and is sealed to the stainless steel base 1. The stainless steel support 2 has a through hole 21. The vacuum electrode assembly 3 corresponds to the through hole 21 and passes through it, sealingly connecting to it. The vacuum electrode assembly 3 is used to transmit the electrical signal from the gas analyzer to the outside.

[0064] In this embodiment, both the stainless steel base 1 and the stainless steel support member 2 are made of stainless steel. Specifically, the stainless steel base 1 can be formed by welding a cylindrical shell and a flange. The stainless steel support member 2 has a disc-shaped structure, with an edge boss 213 on the lower surface edge and a positioning ring on the inner wall of the mounting hole. The stainless steel support member 2 achieves precise alignment by engaging the edge boss 213 with the positioning ring, and is then fixedly connected by welding.

[0065] Understandably, since the stainless steel base 1 and the stainless steel support component 2 are non-ferromagnetic, the sealed connection achieved by welding the stainless steel base 1 to the sensor body on the gas analyzer fundamentally eliminates the interference of the internal electric field of the ferromagnetic material gas analyzer, thereby ensuring the accuracy of ion trajectory and significantly improving the signal-to-noise ratio, sensitivity, and measurement accuracy of the gas analyzer, thus improving the accuracy of the analysis results. Furthermore, the brazing between the stainless steel base 1 and the stainless steel support component 2 is a metal-to-metal connection with perfectly matched coefficients of thermal expansion and minimal residual welding stress, fundamentally avoiding the risk of microcracks and leaks caused by thermal stress, and greatly improving the airtightness of the feedthrough assembly.

[0066] refer to Figure 4 and Figure 5 As shown, in some embodiments, the through hole 21 includes a central through hole 211 and a plurality of edge through holes 212 located around the central through hole 211. The plurality of edge through holes 212 are arranged at annular intervals, and the diameter of the central through hole 211 is larger than the diameter of the edge through holes 212.

[0067] The vacuum electrode assembly 3 includes a central electrode assembly and several edge electrode assemblies. The central electrode assembly passes through the central through-hole 211 and is sealed to the stainless steel support 2. Each edge electrode assembly passes through a corresponding edge through-hole 212 and is sealed to the stainless steel support 2. It is understood that since the diameter of the central through-hole 211 is larger than the diameter of the edge through-holes, the size of the central electrode assembly is adapted to be larger than the size of the edge electrode assemblies.

[0068] Furthermore, both the central electrode assembly and the edge electrode assembly include a cover ring 31, a ceramic pillar 32, a transition piece 33, and an electrode rod 34.

[0069] Specifically, the ceramic column 32 has a through hole that passes through it along its central axis. The transition piece 33 is fitted onto the ceramic column 32 to seal the ceramic column 32 to the stainless steel support piece 2. The electrode rod 34 passes through the through hole to conduct electrical signals. The cover ring 31 is connected to the top of the ceramic column 32 and fitted onto the electrode rod 34 to seal one end of the through hole.

[0070] In this embodiment, the ceramic pillar 32 is a cylindrical structure made of high-purity alumina ceramic, serving as the insulating body. A metal layer is provided on the welding areas of the ceramic pillar 32 surface. The transition member 33 is a ring-shaped structure made of Kovar alloy material, whose coefficient of thermal expansion is close to that of the ceramic pillar 32, ensuring the sealing and reliability of the structure after welding the transition member 33 to the ceramic pillar 32 and the stainless steel support member 2. Furthermore, by using the transition member 33, the stress caused by the difference in thermal expansion coefficients between the ceramic pillar 32 and the stainless steel support member 2 is effectively buffered, further enhancing the reliability of the weld under thermal cycling.

[0071] In addition, by welding the cover ring to the welding area at the top of the ceramic column 32, the vacuum electrode assembly 3 is provided with double airtight protection, and the mechanical strength and resistance to environmental corrosion of the welding point are also enhanced.

[0072] In some embodiments, the metal layer includes a molybdenum-manganese layer and a nickel layer, which are sequentially disposed in the welding area of ​​the ceramic pillar 32.

[0073] In some embodiments, the transition member 33 is interference-fitted with and welded to the central through hole 211 and the edge through hole 212.

[0074] In this embodiment, the transition piece 33 in the central electrode assembly is interference-fitted with the central through hole 211 and then welded, and the transition piece 33 in the edge electrode assembly is interference-fitted with the edge through hole 212 and then welded. Specifically, the size of the transition piece 33 in the central electrode assembly is designed to be slightly larger than the diameter of the central through hole 211, and then the transition piece 33 is cryogenically treated with liquid nitrogen before being installed into the central through hole 211. Similarly, the size of the transition piece 33 in the edge electrode assembly is designed to be slightly larger than the diameter of the edge through hole 212, and then the transition piece 33 is cryogenically treated with liquid nitrogen before being installed into the edge through hole 212. This embodiment, through this innovative assembly method, achieves pre-tightening of the transition piece 33 and the stainless steel support piece 2 at room temperature and stress release at high temperature, dynamically optimizes the stress distribution at the interface of dissimilar materials, and significantly improves the thermal fatigue resistance.

[0075] In some embodiments, the electrode rod 34 is preferably made of austenitic stainless steel.

[0076] In some embodiments, the surfaces of the stainless steel support 2, the electrode rod 34, the transition member 33, and the cover ring 31 are all nickel-plated to form a coating.

[0077] In another embodiment provided in this application, a brazing fixture is provided for fabricating the feedthrough assembly, with reference to... Figures 1 to 8 As shown, the brazing fixture includes: a fixed base 4 with a protrusion 41 adapted to the mounting hole, a positioning hole 42 corresponding to the through hole 21 on the stainless steel support 2 on the protrusion 41, the positioning hole 42 being used for pre-installing the electrode rod 34 in the vacuum electrode assembly 3; and a fixed block 5 with a cylindrical limiting boss 51 corresponding to the positioning hole 42, the limiting boss 51 being adapted to the through hole 21, and the side wall of the limiting boss 51 having a slot 52 for venting, and the center of the limiting boss 51 having a receiving hole 53 for receiving the vacuum electrode assembly 3. In the working state, the vacuum electrode assembly 3 is inserted into the positioning hole 42, the stainless steel support 2 and the stainless steel base 1 are connected and installed on the protrusion 41, and the fixed block 5 passes through the mounting hole and abuts against the stainless steel support 2.

[0078] In this embodiment, to achieve precise assembly and consistent welding of the feedthrough components, the brazing fixture is designed. Both the fixing base 4 and the fixing block 5 are made of graphite. Before brazing, all electrode rods 34 are precisely inserted into their corresponding positioning holes 42, ensuring that the relative position, spacing, and perpendicularity of all electrode rods 34 are strictly maintained during the welding process. Furthermore, when the fixing block 5 passes through the mounting hole and abuts against the stainless steel support 2, the limiting boss 51 is precisely inserted into the corresponding through hole 21, ensuring that the relative position, spacing, and perpendicularity of all ceramic pillars 32 and transition pieces 33 are strictly maintained during the welding process. Simultaneously, the slot 52 is used for gas extraction or protective gas entry during brazing, further improving welding reliability.

[0079] In another embodiment provided in this application, a method for fabricating a feedthrough component is provided, wherein the feedthrough component is fabricated using the aforementioned brazing fixture, with reference to... Figures 1 to 10 As shown, the preparation method includes:

[0080] S901: After cleaning the surfaces to be welded of the stainless steel bearing 2, electrode rod 34, transition piece 33, and cover ring 31, nickel plating is performed.

[0081] Specifically, in this step, nickel is plated onto the surfaces to be welded of the stainless steel support 2, electrode rod 34, transition piece 33, and cover ring 31 to form a nickel layer. The thickness of the nickel layer is 3~8μm.

[0082] S902: Metallize the welding area of ​​the ceramic column 32 to form a metal layer.

[0083] Specifically, in this step, a molybdenum-manganese layer with a thickness of 15~35μm is first plated on the welding area of ​​the ceramic column 32, and then a nickel layer with a thickness of 3~8μm is plated on.

[0084] S903: The stainless steel bearing 2 and the stainless steel base 1 are assembled and then welded to form a welded part.

[0085] Specifically, in this step, the stainless steel bearing 2 and the stainless steel base 1 are assembled and then laser-welded to form the welded part.

[0086] S904: The transition piece 33 is cryogenically treated in a liquid nitrogen environment and then installed at the corresponding position on the stainless steel support piece 2 to form an interference fit.

[0087] Specifically, in this step, the transition piece 33 is cryogenically treated in a liquid nitrogen environment to shrink its outer diameter, and then quickly assembled into the corresponding through hole 21 of the stainless steel carrier piece 2. After the assembly returns to room temperature, an interference fit structure with preload is formed.

[0088] S905: Insert the electrode rods 34 into the positioning holes 42 on the fixing base 4 respectively.

[0089] In this step, the fixing base 4 is placed on a horizontal workbench beforehand, and then multiple electrode rods 34 are inserted into the corresponding positioning holes 42 on the fixing base 4.

[0090] S906: The welding component, the ceramic column 32, and the cover ring 31 are sequentially fitted onto the corresponding electrode rod 34; wherein the cover ring 31, the ceramic column 32, the transition component 33, and the electrode rod 34 are combined to form the vacuum electrode assembly 3.

[0091] S907: The fixing block 5 is installed in the mounting hole of the stainless steel base 1 and abuts against the stainless steel bearing 2 to form an assembly.

[0092] S908: A copper-based solder sheet is placed between the ceramic pillar 32 and the electrode rod 34, between the ceramic pillar 32 and the transition member 33, and between the transition member 33 and the stainless steel support member 2.

[0093] S909: The assembly is moved into a high-temperature brazing furnace, and the temperature is controlled within the range of 820~850℃. The assembly is held at this temperature for 5~15 minutes to complete the welding.

[0094] It should be noted that by controlling the temperature within the range of 820~850℃ and holding it at this temperature for 5~15 minutes, the copper-based brazing filler metal is ensured to have optimal fluidity. This ensures that the filler metal can fully wet and fill all weld seams to achieve a high-strength bond, while also effectively preventing excessive loss of filler metal due to excessively high temperature or insufficient wetting due to excessively low temperature, thereby improving the reliability of the welding.

[0095] S910: After welding, control the temperature to drop from 800℃ to 500℃ at a cooling rate not exceeding 2℃ / min, control the temperature to drop from 500℃ to 300℃ at a cooling rate of 3-5℃ / min, and then cool to room temperature.

[0096] In this step, residual welding stress is minimized. After this step, the brazed feedthrough assembly is removed from the brazing fixture and tested with a helium mass spectrometer. The leak rate of the feedthrough assembly prepared using this method can reach 1.0 × 10⁻⁶. -11 Below Pa·m³ / s, it meets the stringent sealing requirements of ultra-high vacuum systems.

[0097] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the present invention. Furthermore, the present invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A method for fabricating a feedthrough component, characterized in that, include: After cleaning the surfaces of the stainless steel bearing components, electrode rods, transition components, and cap rings to be welded, nickel plating is performed. The welding area of ​​the ceramic column is metallized to form a metal layer; The stainless steel bearing component is assembled with the stainless steel base and then welded to form a welded component. The transition piece is cryogenically treated in a liquid nitrogen environment and then installed on the corresponding position on the stainless steel carrier to form an interference fit. Insert the electrode rods into the positioning holes on the mounting base respectively; The welding component, the ceramic column, and the cover ring are sequentially fitted onto the corresponding electrode rods; wherein, the cover ring, the ceramic column, the transition component, and the electrode rods are combined to form a vacuum electrode assembly; The fixing block is installed in the mounting hole of the stainless steel base and abuts against the stainless steel bearing to form an assembly; A copper-based solder sheet is placed between the ceramic pillar and the electrode rod, between the ceramic pillar and the transition piece, and between the transition piece and the stainless steel support piece. The assembly is moved into a high-temperature brazing furnace, and the temperature is controlled within the range of 820~850℃. The assembly is held at this temperature for 5~15 minutes to complete the welding. After welding, the temperature is controlled to be cooled from 800℃ to 500℃ at a cooling rate not exceeding 2℃ / min, and then cooled from 500℃ to 300℃ at a cooling rate of 3-5℃ / min, and then cooled to room temperature.

2. The preparation method according to claim 1, characterized in that, After cleaning the surfaces of the stainless steel bearing components, electrode rods, transition components, and cap rings to be welded, nickel plating is performed, including: The stainless steel support, the electrode rod, the transition piece, and the cover ring are plated with a nickel layer of 3-8 μm thickness on the surfaces to be welded.

3. The preparation method according to claim 1, characterized in that, The welded areas of the ceramic column are metallized to form a metal layer, including: A molybdenum-manganese layer with a thickness of 15-35 μm is first plated in the welding area of ​​the ceramic column, followed by a nickel layer with a thickness of 3-8 μm.

4. A feedthrough assembly for a gas analyzer, characterized in that, The feedthrough component is prepared by the preparation method according to any one of claims 1-3, and comprises: A stainless steel base with mounting holes is used to seal and connect to the sensor body on the gas analyzer. A stainless steel support component is installed in the mounting hole and is sealed to the stainless steel base; the stainless steel support component has a through hole. A vacuum electrode assembly, corresponding to and passing through the through hole, is used to transmit electrical signals from the gas analyzer to the outside.

5. The feedthrough component according to claim 4, characterized in that, The through hole includes a central through hole and a plurality of edge through holes located around the central through hole, and the plurality of edge through holes are arranged at circumferential intervals. The vacuum electrode assembly includes a central electrode assembly and several edge electrode assemblies. The central electrode assembly passes through the central through hole and is sealed to the stainless steel carrier. Each edge electrode assembly passes through the corresponding edge through hole and is sealed to the stainless steel carrier.

6. The feedthrough component according to claim 5, characterized in that, Both the central electrode assembly and the edge electrode assembly include a cover ring, a ceramic pillar, a transition piece, and an electrode rod. The ceramic column has a through hole that passes through it along the axis of the ceramic column; The transition piece is fitted onto the ceramic column and is used to seal the connection between the ceramic column and the stainless steel support piece. The electrode rod passes through the through hole and is used to conduct electrical signals; The cap ring is connected to the top of the ceramic column and sleeved on the electrode rod to seal one end of the through hole.

7. The feedthrough component according to claim 6, characterized in that, The ceramic column is made of alumina ceramic, and the welding areas of the ceramic column all have a metal layer; The cap ring is welded to the welding area at the top of the ceramic column; The inner wall of the transition piece is welded to the welding area of ​​the outer wall of the ceramic column, and the outer wall of the transition piece is welded to the stainless steel support.

8. The feedthrough component according to claim 6, characterized in that, The transition piece is a ring-shaped structure made of Kovar alloy, and the transition piece is interference-fitted with and welded to both the central through hole and the edge through hole; and / or The surfaces of the stainless steel support, the electrode rod, the transition piece, and the cover ring are all nickel-plated to form a coating.

9. The feedthrough component according to claim 7, characterized in that, The metal layer includes a molybdenum-manganese layer and a nickel layer; The molybdenum-manganese layer and the nickel layer are sequentially disposed in the welding area of ​​the ceramic column.

10. A brazing fixture, characterized in that, The brazing fixture for fabricating the feedthrough assembly as described in any one of claims 4 to 9 includes: The mounting base has a protrusion adapted to the mounting hole, and a positioning hole is provided on the protrusion corresponding to the through hole on the stainless steel support member. The positioning hole is used for pre-installing the vacuum electrode assembly. The fixing block has a limiting boss corresponding to the positioning hole. The limiting boss is adapted to the through hole, and the side wall of the limiting boss has a slot for venting. The center of the limiting boss has a receiving hole for accommodating the vacuum electrode assembly. In the working state, the vacuum electrode assembly is inserted into the positioning hole, the stainless steel carrier and the stainless steel base are connected and installed on the protrusion, and the fixing block passes through the mounting hole and abuts against the stainless steel carrier.

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