Anti-corrosion graphite gasket composite structure

Abstract

The invention discloses an anti-corrosion graphite gasket composite structure, which comprises a graphite base body, which is formed into a hollow disc-shaped structure and is used for providing a heat conduction function; the special engineering plastic isolating layer is of an annular sleeve structure, sleeves the peripheral edge of the graphite base body and is used for isolating corrosive gas; wherein the graphite base body is in clearance fit with the special engineering plastic isolating layer, and the tolerance zone of the clearance fit is smaller than or equal to 0.3 mm. Compared with the prior art, the invention has better corrosion resistance and more stable heat conduction efficiency, and can prevent graphite dust from polluting the cavity environment.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing, and in particular to a corrosion-resistant graphite gasket composite structure. Background Technology

[0002] Graphite gaskets are high-performance sealing materials, primarily made from natural flake graphite through special chemical treatment and high-temperature expansion. They possess excellent high-temperature resistance, corrosion resistance, and self-lubricating properties, making them widely used in static sealing applications across various industrial sectors. In advanced semiconductor manufacturing processes, graphite gaskets are widely used in the cavities of semiconductor processing equipment, primarily serving sealing and heat conduction functions. As semiconductor process nodes continue to shrink and process requirements become increasingly stringent, it is necessary to add corrosive gases such as WF6 (tungsten hexafluoride) into the cavities to achieve specific process effects.

[0003] Existing graphite gaskets primarily consist of graphite coated on aluminum foil. This structure meets basic thermal conductivity and sealing requirements under conventional process conditions. However, in advanced processes, the introduction of corrosive gases such as WF6 introduces the following technical drawbacks to existing solutions: First, the adhesive has a failure problem. The graphite and aluminum foil are bonded together by an adhesive, but in highly corrosive gas environments such as WF6, the adhesive fails rapidly, causing the graphite to detach and separate from the aluminum foil.

[0004] Second, there is the problem of decreased heat transfer efficiency. Due to the detachment of graphite from aluminum foil, the heat transfer path is disrupted, resulting in a significant decrease in heat transfer efficiency. This leads to a continuous rise in cavity temperature, making it impossible to meet the process temperature control requirements.

[0005] Third, there is the problem of graphite dust pollution. The graphite that detaches due to friction generates dust, which pollutes the cavity environment and leads to a significant decrease in wafer yield.

[0006] Fourth, the issue of corrosion resistance. Existing technologies use a single composite graphite material to form the gasket structure. Graphite itself does not possess anti-corrosion properties, and no matter how the structure is changed, the corrosion resistance problem cannot be fundamentally solved.

[0007] Therefore, there is an urgent need for a new type of graphite gasket product structure that can effectively isolate corrosive gases while maintaining the excellent thermal conductivity of graphite. Summary of the Invention

[0008] The summary of this invention introduces a series of simplified concepts, all of which are simplifications of existing technologies in the field, and will be further explained in detail in the detailed description section. This summary is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0009] The technical problem to be solved by the present invention is to provide a corrosion-resistant graphite gasket composite structure that has better corrosion resistance, more stable heat conduction efficiency, and can avoid graphite dust contamination of the cavity environment compared with the prior art.

[0010] To solve the above technical problems, the present invention provides a corrosion-resistant graphite gasket composite structure, comprising: The graphite matrix is ​​formed into a hollow disc-shaped structure. The specific structure of the graphite matrix is ​​manufactured according to requirements and is not the main improvement point of this application. Prefabricated parts can be used to provide thermal conductivity. A special engineering plastic isolation layer is formed as a circular sleeve structure, which fits onto the outer periphery and the inner edge of the hollow structure of the graphite matrix to isolate corrosive gases; Specialty engineering plastics can be selected from polyetheretherketone (PEEK), polyimide (PI), polyphenylene sulfide (PPS), polyarylene ether nitrile (PEN), ethylene-tetrafluoroethylene copolymer (ETFE), polybenzimidazole (PBI), polyethersulfone (PES), polytetrafluoroethylene (PTFE), polysulfone (PSF), thermoplastic polyimide (TPI), liquid crystal polymer (LCP), or polyetheretherketone (PEK).

[0011] The graphite matrix and the special engineering plastic isolation layer are in a clearance fit, and the tolerance zone of the clearance fit is less than or equal to 0.3 mm.

[0012] First, the applicant emphasizes why the above-mentioned main design concept of this application cannot be understood as a commonly used technical means or a conventional technical choice in the field.

[0013] The graphite matrix and the special engineering plastic isolation layer used in this invention have significantly different physical properties (coefficient of thermal expansion, hardness, elastic modulus, etc.), making it impossible to directly apply conventional tolerance and fit theories to the technical solution of this invention. Considering the operating conditions of semiconductor cavities: 1. It needs to withstand highly corrosive gases such as WF6; 2. It is necessary to ensure heat transfer efficiency (high temperature control accuracy is required); 3. It is necessary to avoid powder shedding and contamination (sensitive to wafer yield); In such a harsh environment, the 0.3mm tolerance zone is not arbitrarily set, but rather specifically designed. If the tolerance zone is designed to be too small, it will cause difficulties in production and assembly (problems with flanging and non-roundness in the die-cutting process, and changes in fit due to differences in thermal expansion between the two materials), leading to product quality issues and significantly increasing production costs. If the tolerance zone is designed to be too large, the technical problem that this invention aims to solve cannot be addressed.

[0014] The invention's design with a tolerance of less than 0.3mm ensures a tight fit between the special engineering plastic isolation layer and the graphite, preventing the infiltration of corrosive gases. This balanced design reflects a holistic consideration of the technical solution, rather than an isolated selection of technical parameters.

[0015] Taking a holistic approach, designing a 0.3mm tolerance zone is not a standard fit value that can be found in mechanical design manuals. Rather, it is a targeted solution for specific technical problems such as graphite-PTFE composite materials, die-cutting processes, and semiconductor corrosion environments, which inevitably requires creative effort.

[0016] Preferably, the anti-corrosion graphite gasket composite structure is further improved such that the special engineering plastic isolation layer is positioned such that the tolerance range of the portion of the special engineering plastic isolation layer above the graphite substrate is +0.1mm, and the tolerance range of the portion of the special engineering plastic isolation layer below the graphite substrate is 0mm. Alternatively, the special engineering plastic isolation layer may be positioned such that the tolerance range of the portion of the special engineering plastic isolation layer below the graphite substrate is +0.1mm, and the tolerance range of the portion of the special engineering plastic isolation layer above the graphite substrate is 0mm.

[0017] Preferably, the corrosion-resistant graphite gasket composite structure is further improved such that the dimensional and positional tolerance roundness of the graphite matrix and / or special engineering plastic isolation layer is 0.1 mm.

[0018] Preferably, the corrosion-resistant graphite gasket composite structure is further improved in that the special engineering plastic isolation layer is made by a die-cutting integral molding process.

[0019] Preferably, the corrosion-resistant graphite gasket composite structure is further improved in that the graphite matrix is ​​manufactured by a die-cutting integral molding process.

[0020] Preferably, the corrosion-resistant graphite gasket composite structure is further improved in that the graphite matrix and the special engineering plastic isolation layer are formed by fitting and splicing them together after being formed by two-stage die-cutting.

[0021] Preferably, the corrosion-resistant graphite gasket composite structure is further improved, wherein the special engineering plastic isolation layer is used to isolate WF6 corrosive gas.

[0022] Preferably, the corrosion-resistant graphite gasket composite structure is further improved such that the axial sidewall of the graphite matrix and the special engineering plastic isolation layer at least partially form surface contact.

[0023] Preferably, the anti-corrosion graphite gasket composite structure is further improved in that the contact position between the axial sidewall of the graphite matrix and the special engineering plastic isolation layer is formed as a concave surface, and the contact position between the special engineering plastic isolation layer and the axial sidewall of the graphite matrix is ​​formed as a convex surface that matches the concave surface. Alternatively, the contact point between the axial sidewall of the graphite matrix and the special engineering plastic isolation layer is formed as a convex surface, and the contact point between the special engineering plastic isolation layer and the axial sidewall of the graphite matrix is ​​formed as a concave surface that matches the convex surface.

[0024] Preferably, the corrosion-resistant graphite gasket composite structure is further improved so that the hollowed-out disc-shaped structure is a ring; Alternatively, a hollowed-out disc-shaped structure is a disc with multiple irregular through holes formed in the middle.

[0025] The working principle of this invention is as follows; This invention adopts the technical principle of dual-material composite structure + gap fit, and achieves synergistic optimization of corrosion resistance and heat conduction through material functional zoning and structural fit design.

[0026] 1. This invention divides the graphite gasket product structure into two functionally different areas; The graphite matrix is ​​located inside and in contact with the heat source, utilizing the high thermal conductivity of graphite to achieve efficient heat conduction.

[0027] The special engineering plastic isolation layer is located on the periphery of the graphite matrix and is in direct contact with corrosive gases. PTFE (polytetrafluoroethylene) has excellent chemical stability and can resist the erosion of strong corrosive gases such as WF6, thus playing a role in isolation and protection.

[0028] By functionally zoning materials, the two functions of "corrosion resistance" and "thermal conductivity" are decoupled, avoiding the contradiction that a single material cannot simultaneously meet the two performance requirements.

[0029] 2. This invention uses a clearance fit to achieve a mechanical connection between the two materials; The outer diameter of the graphite substrate is designed to be 307.55 mm (upper tolerance +0.1 mm, lower tolerance 0 mm). The inner diameter of the special engineering plastic isolation layer is designed to be 308.15mm (upper tolerance 0mm, lower tolerance -0.1mm). After fitting, a clearance tolerance zone of 0.3mm is formed.

[0030] Clearance fits reduce assembly difficulty. Compared to interference fits, clearance fits do not require a large assembly force, thus avoiding damage to brittle graphite materials during assembly. Tolerance zone control ensures fitting accuracy. Through die-cutting process, dimensional tolerances are controlled within ±0.1mm and roundness tolerances are controlled within 0.1mm to ensure uniform fitting clearance and prevent local stress concentration. Furthermore, the two-stage die-cutting process ensures precision by separately manufacturing the graphite matrix and the special engineering plastic isolation layer. The dimensional accuracy of each layer is controlled by a dedicated mold, and then they are assembled by fitting together, thus avoiding the deformation problem caused by the different shrinkage rates of the two materials during one-piece molding.

[0031] The assembled structure utilizes the elastic deformation characteristics of the special engineering plastic separator and the rigid support of the graphite matrix to form a stable mechanical fit. During operation, the gas pressure within the cavity acts on the outer surface of the special engineering plastic separator, making the separator adhere more tightly to the graphite matrix and enhancing structural stability.

[0032] Based on the working principle of the present invention described above, at least the following technical effects can be achieved; 1. Existing technology uses a graphite-coated aluminum foil structure. The adhesive fails under the influence of WF6 gas, causing the graphite to separate from the aluminum foil. This interrupts the heat conduction path, leading to a faster temperature rise in the EUI cycle (MTBC) and failure to meet temperature control requirements. Existing technology uses a single composite material; graphite itself is not corrosion-resistant, and while the aluminum foil has some corrosion resistance, the bonding interface between the graphite and aluminum foil has weak points in the adhesive, failing to fundamentally solve the corrosion problem.

[0033] This invention provides a special engineering plastic isolation layer that completely covers the periphery of a graphite matrix, physically isolating corrosive gases such as WF6 from the graphite matrix. Polytetrafluoroethylene (PTFE) possesses extremely strong chemical inertness, does not react with WF6, and maintains structural integrity.

[0034] Meanwhile, the heat conduction path remains stable, the temperature control meets the process requirements, the temperature remains stable during the MTBC cycle, and corrosive gases are effectively isolated to avoid temperature imbalance.

[0035] 2. In existing technologies, graphite detaches after the adhesive fails, generating dust that contaminates the wafer environment, causing wafer contamination and reduced yield. Furthermore, the graphite layer in existing technologies is exposed to corrosive environments, making corrosion and detachment unavoidable.

[0036] The special engineering plastic isolation layer of this invention completely seals the graphite matrix from the side. Even with long-term use, the graphite matrix will not come into direct contact with corrosive gases, thus avoiding the corrosion and shedding of graphite. This can improve the cleanliness of the cavity environment and significantly improve the wafer yield.

[0037] 3. The structural form of existing technologies necessitates the use of adhesives, making it impossible to avoid the inherent problem of adhesive failure. The adhesives relied upon in existing technologies are organic materials, which are prone to aging and failure under corrosive gases and high temperatures.

[0038] This invention employs a mechanical fit, where the graphite matrix and the special engineering plastic isolation layer are fitted together with a gap, without relying on adhesives. This eliminates the problem of adhesive aging and failure, resulting in a long-term stable structure, extended service life, and extended maintenance cycle.

[0039] 4. Existing technologies using interference fits are prone to damage during assembly due to the brittleness of graphite materials; excessive gaps lead to loose fits and impaired heat conduction. Existing technologies involve a single material in a single molding process, avoiding the need for material matching, but this also prevents the utilization of the performance advantages of different materials.

[0040] This invention employs a two-stage die-cutting process to control the dimensional accuracy of the graphite matrix and the special engineering plastic isolation layer, achieving a 0.3mm gap fit. This eliminates the risk of damage during assembly, resulting in high fit precision, good product consistency, and strong interchangeability.

[0041] 5. Both the special engineering plastic insulating layer and the graphite matrix of this invention possess high temperature resistance (able to withstand semiconductor process temperatures) and electrical shock resistance, meeting the specifications for semiconductor cavity materials. This invention solves the application challenge of graphite gaskets in corrosive gas environments during advanced processes, providing hardware support for further miniaturization of semiconductor process nodes. Attached Figure Description

[0042] The accompanying drawings are intended to illustrate the general characteristics of the methods, structures, and / or materials used in specific exemplary embodiments of the invention, supplementing the description in the specification. However, the drawings are schematic diagrams not drawn to scale and may not accurately reflect the precise structural or performance characteristics of any of the given embodiments. The drawings should not be construed as limiting or restricting the range of numerical values ​​or properties covered by exemplary embodiments of the invention. The invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0043] Figure 1 This is a schematic diagram of the structure of the first embodiment of the present invention.

[0044] Figure 2 This is a schematic cross-section of the special engineering plastic isolation layer of the present invention. Figure 1 .

[0045] Figure 3 This is a schematic cross-section of the special engineering plastic isolation layer of the present invention. Figure 2 .

[0046] Figure 4This is a schematic cross-section of the special engineering plastic isolation layer of the present invention. Figure 3 .

[0047] Figure 5 This is a schematic diagram of the structure of the second embodiment of the present invention.

[0048] Figure 6 This is a schematic cross-section of the special engineering plastic isolation layer of the present invention. Figure 4 .

[0049] Figure 7 This is a schematic cross-section of the special engineering plastic isolation layer of the present invention. Figure 5 .

[0050] Figure 8 This is a schematic diagram of the structure of the third embodiment of the present invention.

[0051] Explanation of reference numerals in the attached figures: 1 is a graphite matrix; 2 is a special engineering plastic isolation layer; 3 is a through hole. Detailed Implementation

[0052] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and various details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art. It should be understood that when an element is referred to as "connected" or "combined" to another element, the element can be directly connected or combined to the other element, or there may be intermediate elements. The difference is that when an element is referred to as "directly connected" or "directly combined" to another element, there are no intermediate elements.

[0053] First embodiment; refer to Figure 1 As shown, the present invention provides a corrosion-resistant graphite gasket composite structure, comprising: Graphite matrix 1, which is formed in the form of a ring, is used to provide thermal conductivity; The special engineering plastic isolation layer 2 is formed as a circular sleeve structure and fits onto the outer periphery of the graphite matrix 1 to isolate corrosive gases; The graphite substrate 1 and the special engineering plastic isolation layer 2 are in a clearance fit, and the tolerance zone of the clearance fit is less than or equal to 0.3 mm.

[0054] For example, the graphite matrix 1 is made of high thermal conductivity graphite material with a thermal conductivity ≥100 W / (m·K) and has a circular hollow structure. The outer diameter is assumed to be 300mm ~ 320mm, with an upper tolerance of +0.1mm and a lower tolerance of 0mm. The inner diameter is assumed to be 280mm, which is determined according to the size of the equipment interface. The thickness is 5mm. The form and position tolerance is roundness 0.1mm.

[0055] The special engineering plastic isolation layer 2 is made of polytetrafluoroethylene (the same applies to other special engineering plastics mentioned above), with a purity of ≥99%; it is a circular sleeve structure; the inner diameter is assumed to be 300mm ~ 320mm, with an upper tolerance of 0mm and a lower tolerance of -0.1mm; the wall thickness is 2mm; the height matches the thickness of the graphite matrix 1, which is 5mm; the form and position tolerance is roundness of 0.1mm.

[0056] The graphite substrate 1 is fitted inside the special engineering plastic isolation layer 2, and a clearance fit is formed between the two. The clearance is 0.3mm (theoretical value), and the actual clearance range is 0.1mm~0.5mm (considering the cumulative tolerance).

[0057] Options are available; please refer to them. Figure 2 , Figure 3 and Figure 4 As shown, the axial sidewall of the graphite substrate 1 and the special engineering plastic isolation layer 2 form at least partial surface contact at their contact points. Surface contact increases friction and prevents relative displacement between the graphite substrate 1 and the special engineering plastic isolation layer 2. The other side of the graphite substrate 1 is formed as a concave surface, or the other side of the special engineering plastic isolation layer 2 is formed as a concave surface.

[0058] Options are available; please refer to them. Figure 6 and Figure 7 As shown, the contact point between the axial sidewall of the graphite substrate 1 and the special engineering plastic isolation layer 2 is formed as a concave surface, and the contact point between the special engineering plastic isolation layer 2 and the axial sidewall of the graphite substrate 1 is formed as a convex surface that mates with the concave surface. The contact between the concave and convex surfaces increases the frictional force and prevents relative displacement between the graphite substrate 1 and the special engineering plastic isolation layer 2.

[0059] Based on the structure of the first embodiment described above, the preferred manufacturing process of the present invention is provided as follows; Step 1: Molding of graphite matrix 1; The graphite material is placed in a special mold and stamped into a ring structure using a die-cutting process. The mold precision is controlled within ±0.05mm to ensure that the outer diameter of the graphite substrate 1 meets the design requirements and the roundness is 0.1mm.

[0060] Step 2: Molding of the special engineering plastic isolation layer 2; The process employs a die-cutting molding technique, placing polytetrafluoroethylene (PTFE) material in a specialized mold and cold-pressing it into a circular sleeve structure. The mold precision is controlled within ±0.05mm to ensure that the inner diameter of the special engineering plastic isolation layer 2 meets the design requirements, with a roundness of 0.1mm.

[0061] Step 3: Fitting and assembly; The formed graphite substrate 1 is inserted into one end of the special engineering plastic isolation layer 2. Due to the use of a clearance fit, the fitting process does not require heating or pressurization and can be completed manually. After fitting, a uniform gap is formed between the outer circumferential surface of the graphite substrate 1 and the inner circumferential surface of the special engineering plastic isolation layer 2, with a gap value of 0.3 mm (theoretical center value).

[0062] Based on the structure of the first embodiment described above, an exemplary description of the usage process of the present invention is provided; The assembled corrosion-resistant graphite gasket composite structure is installed at the cavity interface of the LAM Flex device. The outer circumferential surface of the special engineering plastic isolation layer 2 is in contact with the inner wall of the cavity, directly exposed to corrosive gas environments such as WF6. The inner circumferential surface of the graphite matrix 1 is in contact with the heat source to achieve heat conduction.

[0063] During operation, WF6 gas comes into contact with the special engineering plastic isolation layer 2. Due to the chemical inertness of polytetrafluoroethylene (PTFE), no corrosion reaction occurs. The graphite matrix 1 is completely encapsulated by the special engineering plastic isolation layer 2, isolating it from corrosive gases and maintaining structural integrity and thermal conductivity.

[0064] Based on the structure of the first embodiment described above, the performance verification of the present invention is provided as follows; 1. Corrosion test: The product of this embodiment was placed in a WF6 gas environment (concentration assumed to be 100 ppm, temperature assumed to be 200°C) and continuously operated for 100 MTBCs (Mean Time Between Failures). The test results showed: The surface of the special engineering plastic isolation layer 2 shows no signs of corrosion; No powder shedding was observed in graphite substrate 1; The structure remains intact, with no loosening or detachment.

[0065] 2. Temperature control test: Tested under actual operating conditions of the LAM Flex equipment, the IUE temperature remained stable within the MTBC cycle, the temperature rise rate met the process requirements, and there was no continuous temperature rise phenomenon as seen in existing technologies.

[0066] Second embodiment; Referring to Figure 5, this invention provides a corrosion-resistant graphite gasket composite structure. The second embodiment differs from the first embodiment in its dimensions and the perforated structure of the graphite matrix, making it suitable for different types of semiconductor processing equipment, including: The graphite matrix 1 is formed as a multi-layered annular structure that is connected to each other by connecting ribs / reinforcing ribs and nested together to provide thermal conductivity. A special engineering plastic isolation layer 2 is fitted around the outer periphery of the graphite matrix 1 to isolate corrosive gases; The graphite substrate 1 and the special engineering plastic isolation layer 2 are in a clearance fit, and the tolerance zone of the clearance fit is less than or equal to 0.3 mm.

[0067] The graphite substrate 1 is assumed to have an outer diameter range of 180mm to 220mm (determined according to the device interface size), with an upper tolerance of +0.1mm and a lower tolerance of 0mm; other parameters are the same as in the first embodiment and will not be repeated.

[0068] The special engineering plastic isolation layer 2 is assumed to have an inner diameter range of 200mm~220mm (determined based on the outer diameter of the graphite matrix + 0.3mm gap), an upper tolerance of 0mm, and a lower tolerance of -0.1mm; other parameters are the same as in the first embodiment and will not be repeated.

[0069] Options are available; please refer to them. Figure 2 , Figure 3 and Figure 4 As shown, the axial sidewall of the graphite substrate 1 and the special engineering plastic isolation layer 2 form at least partial surface contact at their contact points. Surface contact increases friction and prevents relative displacement between the graphite substrate 1 and the special engineering plastic isolation layer 2. The other side of the graphite substrate 1 is formed as a concave surface, or the other side of the special engineering plastic isolation layer 2 is formed as a concave surface.

[0070] Options are available; please refer to them. Figure 6 and Figure 7 As shown, the contact point between the axial sidewall of the graphite substrate 1 and the special engineering plastic isolation layer 2 is formed as a concave surface, and the contact point between the special engineering plastic isolation layer 2 and the axial sidewall of the graphite substrate 1 is formed as a convex surface that mates with the concave surface. The contact between the concave and convex surfaces increases the frictional force and prevents relative displacement between the graphite substrate 1 and the special engineering plastic isolation layer 2.

[0071] The assembly and working principle of the second embodiment are the same as those of the first embodiment, and will not be described again.

[0072] Third embodiment; refer to Figure 8 As shown, this invention provides a corrosion-resistant graphite gasket composite structure. The difference between the third embodiment and the first embodiment lies in the size specifications and the perforated structure of the graphite matrix, making it suitable for different types of semiconductor processing equipment, including: The graphite substrate 1 is formed as a disk structure with multiple through holes 3. The specific shape and position of the through holes 3 are set as needed, and are not limited to circular through holes. They can be irregularly shaped through holes to provide heat conduction function. The special engineering plastic isolation layer 2 is formed as a circular sleeve structure, which fits onto the outer periphery of the graphite substrate 1 and the inner edge of each through hole 3, and is used to isolate corrosive gases. The graphite substrate 1 and the special engineering plastic isolation layer 2 are in a clearance fit, and the tolerance zone of the clearance fit is less than or equal to 0.3 mm.

[0073] The assembly and working principle of the third embodiment are the same as those of the first embodiment, and will not be described again.

[0074] Optionally, in the first to third embodiments described above, the special engineering plastic isolation layer 2 is formed by splicing 2 to 4 arc-shaped polytetrafluoroethylene (PTFE) segments to form a complete ring. Each segment is connected by an overlap, with the overlap width assumed to be 5 mm. The segmented structure reduces the molding difficulty of large PTFE products and facilitates the replacement of partially damaged PTFE segments.

[0075] The graphite substrate 1 can adopt an integral structure or a corresponding segmented structure. The dimensional tolerances and fit relationships are the same as in the first embodiment and will not be repeated here.

[0076] The difference in manufacturing process is that each polytetrafluoroethylene (PTFE) segment is molded separately, then spliced ​​into a complete ring, and then fitted with the graphite matrix 1. Other steps are the same as in the first embodiment and will not be repeated here.

[0077] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will also be understood that, unless explicitly defined herein, terms such as those defined in a general dictionary shall be interpreted as having the meaning consistent with their meaning in the relevant field context, and not as having an idealized or overly formal meaning.

[0078] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A corrosion-resistant graphite gasket composite structure, characterized in that, include: The graphite matrix (1) is formed into a hollow disk-shaped structure to provide thermal conductivity; A special engineering plastic isolation layer (2) is formed as a ring-shaped sleeve structure, which fits around the outer periphery and the inner edge of the hollow structure of the graphite matrix (1) to isolate corrosive gases; The graphite matrix (1) and the special engineering plastic isolation layer (2) are in a clearance fit, and the tolerance zone of the clearance fit is less than or equal to 0.3 mm.

2. The anti-corrosion graphite gasket composite structure as described in claim 1, characterized in that: The graphite substrate (1) and the special engineering plastic isolation layer (2) are positioned such that the tolerance range of the portion of the special engineering plastic isolation layer (2) above the graphite substrate (1) is +0.1mm, and the tolerance of the portion of the special engineering plastic isolation layer (2) below the graphite substrate (1) is 0mm. Alternatively, the special engineering plastic isolation layer (2) is positioned such that the tolerance range of the portion of the special engineering plastic isolation layer (2) below the graphite substrate (1) is +0.1mm, and the tolerance range of the portion of the special engineering plastic isolation layer (2) above the graphite substrate (1) is 0mm.

3. The anti-corrosion graphite gasket composite structure as described in claim 1 or 2, characterized in that: The dimensional and positional tolerances of the graphite matrix (1) and / or the special engineering plastic isolation layer (2) are 0.1 mm.

4. The anti-corrosion graphite gasket composite structure as described in claim 1, characterized in that: The special engineering plastic isolation layer (2) is made by a die-cutting integral molding process.

5. The anti-corrosion graphite gasket composite structure as described in claim 1, characterized in that, The graphite matrix (1) is made by a die-cutting process.

6. The anti-corrosion graphite gasket composite structure as described in claim 1, characterized in that: The graphite matrix (1) and the special engineering plastic isolation layer (2) are formed by fitting and splicing them together after being formed by two-stage die cutting.

7. The anti-corrosion graphite gasket composite structure as described in claim 1, characterized in that: The special engineering plastic isolation layer (2) is used to isolate WF6 corrosive gas.

8. The anti-corrosion graphite gasket composite structure as described in claim 1, characterized in that: The axial sidewall of the graphite matrix (1) and the special engineering plastic isolation layer (2) at least partially form a surface contact.

9. The anti-corrosion graphite gasket composite structure as described in claim 8, characterized in that: The contact position between the axial sidewall of the graphite matrix (1) and the special engineering plastic isolation layer (2) is formed as a concave surface, and the contact position between the special engineering plastic isolation layer (2) and the axial sidewall of the graphite matrix (1) is formed as a convex surface that matches the concave surface; Alternatively, the contact position between the axial sidewall of the graphite substrate (1) and the special engineering plastic isolation layer (2) is formed as a convex surface, and the contact position between the special engineering plastic isolation layer (2) and the axial sidewall of the graphite substrate (1) is formed as a concave surface that matches the convex surface.

10. The anti-corrosion graphite gasket composite structure as described in claim 1, characterized in that: The hollowed-out disc-shaped structure is a ring; Alternatively, a hollowed-out disc-shaped structure is a disc with multiple irregular through holes formed in the middle.

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