Pneumatic high pressure valve for semiconductor supercritical cleaning apparatus and method of assembling the same

Abstract

The present application relates to the technical field of pressure valve, and discloses a pneumatic high-pressure valve for semiconductor supercritical cleaning equipment and an assembling method thereof.The pneumatic high-pressure valve comprises a cylinder assembly, a plastic diaphragm and a plastic valve seat.A center step and an elastic washer are arranged in the cylinder body, and the piston has an annular step surface matched with the elastic washer.During the closing process of the valve, the piston first compresses the elastic washer to buffer and decelerate, and then drives the diaphragm to seal the valve port, so that soft landing is realized, and the particles generated by the impact of the high-pressure valve during closing are eliminated from the root.Meanwhile, the diaphragm adopts a multi-stage clamping groove structure, and cooperates with the dead-zone-free flow channel of the valve seat, so that the diaphragm can withstand 8.0Mpa supercritical fluid pressure and realize almost zero leakage and zero metal ion precipitation.

Description

Technical Field

[0001] This invention relates to the field of pressure valve technology, and in particular to a pneumatic high-pressure valve for semiconductor supercritical cleaning equipment and its assembly method. Background Technology

[0002] Wafer cleaning is a crucial step in semiconductor manufacturing. Traditional water-based and plasma cleaning methods, due to the surface tension of the liquid, can easily damage thin films in high aspect ratio structures, adversely affecting the performance of semiconductor devices. With the continuous development of semiconductor technology, the requirements for wafer cleaning are becoming increasingly stringent, leading to the development of supercritical carbon dioxide (sCO2) cleaning technology. This cleaning technology has unique advantages; it can thoroughly remove residues from deep holes and trenches of wafers without damaging fragile nanostructures, providing a more reliable cleaning solution for semiconductor manufacturing and gaining widespread attention and application in the field of semiconductor equipment technology.

[0003] However, supercritical carbon dioxide cleaning processes place unprecedented and extremely stringent technical requirements on valve components in pipeline systems. Specifically, in terms of high-pressure withstand capability, the critical point of carbon dioxide is 31.1℃ and 7.38MPa. In actual processes, to ensure the fluid remains stably in a supercritical state and possesses sufficient cleaning capacity, the operating pressure is typically maintained above 8.0MPa, posing a significant challenge to the valve's sealing structure and shell strength. Regarding cleanliness, semiconductor manufacturing environments are extremely sensitive to particulate contamination. Therefore, the process environment must meet ISO Class 1 standards. During frequent opening and closing of valves, any mechanical impact, friction, or wear on internal components must be carefully avoided to prevent the generation of new particles. Furthermore, contamination by metal ions (such as Na+, K+, Fe3+, etc.) can severely affect the electrical performance of semiconductor devices, leading to problems such as gate oxide breakdown and increased leakage current. Therefore, valve components in direct contact with the supercritical carbon dioxide fluid must be made of non-metallic materials to fundamentally prevent the precipitation and migration of metal ions. In terms of flow channel design, any area inside the valve chamber that may cause fluid stagnation or residue (dead zones or dead ends) will become a hiding place for contaminants and cause cross-contamination in subsequent processes. Therefore, the flow channel must have a smooth transition, be easy to purge, and ensure displacement efficiency.

[0004] Utility model patent CN214274495U discloses a high-strength pneumatic regulating valve, including a valve body, a plastic valve core, a valve seat, a valve cover, a valve stem, and a pressure plate. The valve seat is disposed within the valve body, the plastic valve core is disposed within a channel of the valve seat, and the valve cover is detachably disposed at the upper end of the valve body. The valve stem passes through the valve cover into the valve body and is fixedly connected to the plastic valve core. A drive cylinder is disposed at the upper end of the valve body, and the end of the valve stem extending out of the valve cover is connected to the drive shaft of the drive cylinder. An indicating mechanism is also included at the bottom of the cylinder. A metal part is embedded within the plastic valve core, and the metal part has a threaded hole. A tensile portion perpendicular to the axial direction of the threaded hole is sleeved on its outer side. The valve stem is threadedly connected to the metal part. Although this solution proposes a high-strength pneumatic regulating valve, the metal part embedded within the plastic valve core allows metal ions to easily precipitate through the micropores of the polymer material under the strong permeability of supercritical fluids.

[0005] Chinese patent publication CN115711305A discloses a high-pressure diaphragm valve and its control method, including a valve body, a valve seat, a diaphragm, and a top post. The valve body has a valve seat, and a diaphragm is mounted on the valve seat via a diaphragm cover. A top post, coaxially aligned with the valve seat, is located inside the diaphragm cover. One end of the top post is in contact with the diaphragm, and the other end is sealed to an actuator. The actuator includes a cylinder body, a cylinder cover, a lower piston, and an upper piston positioned between the two. The upper piston is movably mounted inside the lower piston. Hydraulic oil is sealed between the lower piston, the cylinder body, and the upper piston. A pair of disc springs are also mounted at both ends of the lower piston, facing the upper piston. The disc springs are in a pre-compressed state when installed inside the cylinder body. Although this solution uses hydraulic buffering, its structure is complex, and there is a risk of hydraulic oil leakage and contamination of the cleanroom. More importantly, its disc spring pre-compression design mainly addresses the sealing force issue and does not effectively absorb the kinetic energy of the valve core contacting the valve seat, thus failing to eliminate particles generated by the impact.

[0006] Utility model patent publication number CN213451764U discloses a pneumatic pressure regulating valve for high-pressure cleaning equipment, including a valve body and a valve seat disposed within the valve body. A valve cover, guide cylinder, bracket, spring sleeve, and pneumatic actuator are sequentially connected vertically to the top of the valve body. An air inlet is provided at the top of the pneumatic actuator, and a diaphragm is movably connected within the actuator. A pneumatic block is fixedly connected to the diaphragm, located below the air inlet. A valve stem is fixedly connected to the bottom of the pneumatic block, with its bottom end located within the valve body and fitted with a V-shaped valve core that matches the shape of the valve seat. The valve cover and valve body are integrally formed, and the valve cover and guide cylinder are detachably fixedly connected. A channel through which the V-shaped valve core can pass is provided on the valve cover. A gap exists between the inner wall of the channel and the valve stem, and an elastic element is disposed within the gap. The top end of the elastic element is connected to the guide cylinder, and a buffer plate is connected to the bottom end of the elastic element. The buffer plate is sleeved on the valve stem, located above the V-shaped valve core and within the channel. The proposed solution discloses a buffer plate structure, but the buffer plate is located above the valve stem and is mainly used to protect the actuator rather than the sealing interface; moreover, its V-shaped valve core structure is prone to forming dead corners at the sealing point, resulting in chemical reagent residues, which does not meet the stringent standard of sCO2 cleaning for a dead-zone-free flow channel. Summary of the Invention

[0007] The main objective of this invention is to provide a pneumatic high-pressure valve for semiconductor supercritical cleaning equipment. The main improvement is that it is suitable for semiconductor supercritical cleaning equipment that requires high pressure of 8.0 MPa, clean valve cavity with no dead zone, extremely close to zero leakage, and almost no particle and metal ion precipitation.

[0008] The second main objective of this invention is to provide a method for assembling a pneumatic high-pressure valve for a semiconductor supercritical cleaning equipment, wherein the assembled pneumatic high-pressure valve is suitable for semiconductor supercritical cleaning equipment.

[0009] The main objective of this invention is achieved through the following technical solution: a pneumatic high-pressure valve for semiconductor supercritical cleaning equipment is provided, comprising:

[0010] A cylinder assembly includes a cylinder top cover, a cylinder body, and a piston. The cylinder top cover is mounted on the cylinder body, and the cylinder body has a piston chamber and a central hole that are interconnected. A central step is formed at the transition between the piston chamber and the central hole, and an elastic washer is provided on the central step. The piston is housed in the piston chamber and extends through the elastic washer into the central hole.

[0011] A plastic diaphragm has a sealing diaphragm portion and a valve core integrally located at the center; the sealing diaphragm portion has a first sealing flange and a second sealing flange sequentially arranged outward from the center; the valve core has a threaded portion at the upper part and a valve core platform at the lower part, and the threaded portion is connected to the bottom end of the piston;

[0012] A plastic valve seat has an internal valve port and an inlet and outlet flow channel communicating with the valve port. The upper surface of the plastic valve seat has a first valve seat groove and a second valve seat groove arranged sequentially from the center outwards. The plastic valve seat supports the cylinder assembly and the plastic diaphragm. A first sealing flange is installed in the first valve seat groove, and a second sealing flange is installed in the second valve seat groove. The valve core platform is located at the valve port. The piston is configured to move up and down to drive the valve core platform to seal or disengage from the valve port. The elastic washer provides cushioning during the downward movement of the piston to reduce the impact intensity between the plastic diaphragm and the plastic valve seat.

[0013] The implementation principle of this basic structural example is to utilize the geometric interference between the central step set inside the cylinder and the piston's downward path, introducing an elastic washer as a deceleration medium. When the driving gas is discharged, the normally closed spring releases its potential energy to push the piston downward to close the valve. The annular stepped surface of the piston will contact the elastic washer placed on the central step before the diaphragm valve core. The elastic washer deforms under pressure, absorbing most of the piston's kinetic energy, causing the piston to change from rapid movement to damped slow movement, thereby gently pressing the diaphragm valve core into the valve seat groove, achieving a "soft landing" seal. Specific effects include:

[0014] 1) Effectively suppresses particle generation, meeting the stringent cleanliness requirements of semiconductor cleaning. By placing an elastic washer on the central step of the cylinder, when the piston rapidly descends under the drive of the spring to close the valve, the piston's step surface first contacts the elastic washer for buffering and deceleration, thus achieving a "soft landing." This avoids rigid, rapid impact between the plastic diaphragm and the plastic valve seat, virtually eliminating particles generated by impact friction at the source.

[0015] 2) High cleanliness and corrosion resistance are achieved inside the valve chamber. The valve chamber in contact with the fluid is constructed using a plastic (PEEK) valve seat and a plastic (PTFE) diaphragm, completely eliminating the use of metal materials. This prevents metal ion precipitation and contamination of the wafer, while ensuring excellent resistance to chemical fluids such as supercritical carbon dioxide.

[0016] 3) Possesses high-pressure resistance and dead-zone-free sealing capability. The structural design can withstand supercritical fluid pressure of 8.0 MPa, and the precise fit between the diaphragm and the valve seat eliminates dead zones within the valve, preventing residue accumulation and ensuring the thoroughness of the cleaning process.

[0017] In a preferred embodiment, the present invention may be further configured such that the plastic diaphragm is made of PTFE, wherein the flexible length of the sealing diaphragm portion of the plastic diaphragm is less than or equal to 2.5 times the diaphragm thickness; and the plastic valve seat is made of PEEK.

[0018] By adopting the preferred technical features of the above structure, the flexible length of the sealing diaphragm of the PTFE diaphragm is limited (≤2.5 times the thickness), which effectively prevents the diaphragm from excessively deforming or fatigue-breaking under high pressure (8.0 MPa). While ensuring that the diaphragm has sufficient flexibility to perform switching actions, the service life of the diaphragm is significantly extended, and the long-term reliability of the valve in supercritical environments is improved.

[0019] In a preferred embodiment, the present invention may be further configured such that the sealing diaphragm portion is provided with a sealing water line protrusion between the first sealing flange and the second sealing flange and between the first sealing flange and the valve core, the sealing water line protrusion being located above the contact plane between the plastic valve seat and the sealing diaphragm portion.

[0020] By employing the optimized technical features of the aforementioned structure, the sealing waterline protrusion concentrates the preload between the valve seat and the diaphragm onto a very small contact area, thereby generating extremely high local contact pressure. This high-pressure contact effectively cuts off the microscopic leakage path of the high-pressure fluid, greatly improving sealing performance and ensuring zero leakage under the high permeability conditions of supercritical carbon dioxide.

[0021] In a preferred embodiment, the present invention may be further configured such that the first sealing flange is installed in the first valve seat groove by an interference fit, and the second sealing flange is installed in the second valve seat groove by an interference fit; wherein, both the first sealing flange and the second sealing flange have a beveled side near the valve core and a straight side away from the valve core; the beveled side is used for guiding installation; the straight side is opposite to the beveled side and is used to block fluid pressure.

[0022] By adopting the optimized technical features of the above structure, an asymmetrical structure combining beveled and straight sides is used, balancing ease of assembly and sealing reliability. The beveled side near the valve core acts as a guide, allowing the diaphragm flange to be smoothly pressed into the valve seat groove, using an interference fit to avoid assembly damage; while the straight side away from the valve core serves as the main pressure-bearing surface, effectively blocking internal fluid pressure during valve operation, preventing the sealing flange from being squeezed out or deformed by high pressure, further ensuring the stability of the seal.

[0023] In a preferred embodiment, the present invention can be further configured such that the piston includes an integrally formed piston body, an upper piston rod, and a lower piston rod. The upper piston rod is connected to the upper end face of the piston body, and the lower piston rod is connected to the lower end face of the piston body. A receiving cavity is provided within the cylinder cover. The piston body is housed within the piston cavity, and an impeller structure surrounding the lower piston rod is provided on the lower end face of the piston body. The impeller structure generates a tangential torque under the action of the intake airflow to suppress piston rotation. The upper piston rod is housed within the receiving cavity, and a normally closed inner spring and a normally closed outer spring are sequentially sleeved on the upper piston rod from the inside to the outside. The lower piston rod extends from the piston cavity into the central hole, and a threaded hole for installing a plastic diaphragm is provided at the bottom end of the lower piston rod. The lower piston rod has an annular stepped surface. The radial width of the annular stepped surface matches the radial width of the elastic washer, allowing it to contact the elastic washer during the downward movement of the piston, thereby decelerating the piston.

[0024] By adopting the preferred technical features of the above structure, on the one hand, the impeller structure on the lower end face of the piston uses the intake airflow to generate tangential torque, which can effectively prevent the piston from rotating during reciprocating motion, thereby avoiding loosening at the threaded connection between the piston and the diaphragm and solving the risk of seal failure caused by loose threads; on the other hand, the annular stepped surface of the piston rod at the lower end of the piston matches the radial width of the elastic washer, ensuring the precise execution of the buffer deceleration effect and guaranteeing the stability of the "anti-impact particle generation" function.

[0025] In a preferred embodiment, the present invention can be further configured such that: a piston body sealing ring is mounted on the piston body; an upper piston sealing ring is mounted on the upper piston rod; and a lower piston sealing ring is mounted on the lower piston rod; the piston body sealing ring, the upper piston sealing ring, and the lower piston sealing ring are used to seal the gap between the piston and the cylinder head and the cylinder body; a valve seat sealing ring is mounted on the plastic valve seat, and the valve seat sealing ring is used to seal the gap between the cylinder body and the plastic valve seat; the cylinder head and the cylinder body are locked together by cylinder bolts and cylinder washers, and the cylinder bolts are fitted with cylinder anti-corrosion plugs; the plastic valve seat and the cylinder body are locked together by valve seat bolts and valve seat washers, and the valve seat bolts are fitted with valve seat anti-corrosion plugs.

[0026] By employing the optimized technical features of the above structure, the multi-seal design (piston upper / lower / body seals and valve seat seals) constructs a complete internal and external isolation system, preventing both drive gas leakage and external environmental contamination of the process chamber. Combined with the use of anti-corrosion plugs, it effectively protects the locking bolts from corrosion by the cleanroom environment or trace amounts of chemical gases, improving the overall durability and cleanliness level of the machine.

[0027] In a preferred embodiment, the present invention may further include: a photoelectric switch, mounted on the cylinder cover, for detecting the position of the piston to determine the on / off state of the pneumatic high-pressure valve, and generating a valve position open signal and a valve position closed signal.

[0028] By adopting the optimized technical features of the above structure, real-time monitoring and digital feedback of the on / off status of the pneumatic high-pressure valve are achieved. The on / off signal generated by detecting the piston position can be directly connected to the PLC control system of the semiconductor equipment, facilitating automated program control, fault alarms, and safety interlocks in the cleaning process, thus improving the equipment's intelligence level.

[0029] The second main objective of this invention is achieved through the following technical solution: a method for assembling a pneumatic high-pressure valve for semiconductor supercritical cleaning is proposed, comprising the following steps:

[0030] S1. Assemble a cylinder assembly, the cylinder assembly including a cylinder top cover, a cylinder body and a piston, the cylinder top cover being mounted on the cylinder body, the cylinder body having a piston chamber and a central hole communicating with each other; wherein, a central step is formed at the transition between the piston chamber and the central hole, an elastic washer is provided on the central step, the piston is accommodated in the piston chamber and extends through the elastic washer into the central hole;

[0031] S2. Install a plastic diaphragm at the bottom end of the piston. The plastic diaphragm has a sealing diaphragm portion and a valve core integrally disposed at the center. The sealing diaphragm portion is provided with a first sealing flange and a second sealing flange in sequence from the center outward. The valve core has a threaded portion at the upper part and a valve core platform at the lower part. The threaded portion is connected to the bottom end of the piston.

[0032] S3. Install the cylinder assembly and the plastic diaphragm onto the plastic valve seat. The plastic valve seat has a valve port and an inlet flow channel and an outlet flow channel communicating with the valve port. The upper surface of the plastic valve seat has a first valve seat groove and a second valve seat groove arranged sequentially from the center outward. The plastic valve seat supports the cylinder assembly and the plastic diaphragm. The first sealing flange is installed in the first valve seat groove, and the second sealing flange is installed in the second valve seat groove. The valve core platform is located at the valve port. The piston is configured to move up and down to drive the valve core platform to seal or disengage from the valve port. The elastic washer is used to provide cushioning during the downward movement of the piston to reduce the impact intensity between the plastic diaphragm and the plastic valve seat.

[0033] This basic method example demonstrates the efficient assembly of a pneumatic high-pressure valve, ensuring that all components work together to achieve superior performance, including high pressure resistance of 8.0 MPa, a clean valve cavity with no dead zones, extremely close to zero leakage, and virtually no particle or metal ion precipitation. Specific results are as follows:

[0034] 1. The effective construction of the core buffer mechanism was ensured. The assembly steps clearly defined the installation sequence and positional relationship between the elastic gasket and the piston assembly, ensuring that the assembled valve could accurately trigger the deceleration mechanism at the moment of closure, thereby stably achieving the technical target of low particle generation.

[0035] 2. The integrity of the interference seal structure is ensured. The diaphragm installation steps specified in this method, combined with the beveled guide design, allow the PTFE diaphragm to be embedded into the valve seat with the correct interference fit, avoiding material scratches or stress concentration caused by forced assembly, and ensuring sealing performance under high pressure.

[0036] 3. Improved assembly precision and efficiency. The modular assembly process (cylinder first, then diaphragm, then assembly) helps ensure coaxial alignment, reduces assembly errors, and results in high consistency of the manufactured high-pressure valves, enabling them to be quickly put into use on semiconductor production lines.

[0037] In a preferred embodiment, the present invention may further include:

[0038] Step S4: Install anti-corrosion plugs on the cylinder assembly and the plastic valve seat; Step S5: Install photoelectric switches on the cylinder assembly;

[0039] The photoelectric switch is installed on the cylinder cover and is used to detect the position of the piston to determine the on / off state of the pneumatic high-pressure valve and generate valve position open signal and valve position closed signal.

[0040] By adopting the optimized technical features of the above method, the installation of anti-corrosion components and detection components is integrated into the standardized assembly process, ensuring that every high-pressure valve leaving the factory has complete protection capabilities and intelligent feedback capabilities, avoiding the risk of structural loosening or seal damage that may occur during later installation.

[0041] In a preferred embodiment, the present invention can be further configured such that, in step S1, the piston includes an integrally formed piston body, an upper piston rod, and a lower piston rod. The upper piston rod is connected to the upper end face of the piston body, and the lower piston rod is connected to the lower end face of the piston body. The cylinder cover has a receiving cavity. The piston body is housed within the piston cavity, and the lower end face of the piston body has an impeller structure surrounding the lower piston rod. The upper piston rod is housed within the receiving cavity, and a normally closed inner spring and a normally closed outer spring are sequentially sleeved on the upper piston rod from the inside to the outside. The lower piston rod extends from the piston cavity into the central hole, and the bottom end of the lower piston rod has a threaded hole for installing a plastic diaphragm. The lower piston rod also has an annular stepped surface. The radial width of the annular stepped surface matches the radial width of the elastic washer, allowing it to contact the elastic washer during the downward movement of the piston, thereby slowing down the piston.

[0042] In step S3, the first sealing flange is installed in the first valve seat groove by interference fit, and the second sealing flange is installed in the second valve seat groove by interference fit; wherein, both the first sealing flange and the second sealing flange have a beveled side near the valve core and a straight side away from the valve core; the beveled side is used for guiding installation; the straight side is opposite to the beveled side and is used to block fluid pressure.

[0043] By adopting the preferred technical features of the above method, the impeller orientation and step surface matching are clearly defined during the assembly process, ensuring that the physical basis for the piston anti-rotation function and deceleration function is correctly established; at the same time, the interference fit guided by the bevel is used in the diaphragm installation step, which reduces the assembly difficulty and improves the first-pass yield rate of assembly.

[0044] In a preferred embodiment, the present invention can be further configured such that, in step S1, a piston body sealing ring is mounted on the piston body, an upper piston sealing ring is mounted on the upper piston rod, and a lower piston sealing ring is mounted on the lower piston rod. The piston body sealing ring, the upper piston sealing ring, and the lower piston sealing ring are used to seal the gap between the piston and the cylinder head and the cylinder body; the cylinder head and the cylinder body are locked together by cylinder bolts and cylinder washers.

[0045] In step S3, a valve seat sealing ring is installed on the plastic valve seat, and the valve seat sealing ring is used to seal the gap between the cylinder body and the plastic valve seat; the plastic valve seat and the cylinder body are locked together by valve seat bolts and valve seat washers.

[0046] In step S4, the cylinder anti-corrosion plug is installed on the cylinder bolt, and the valve seat anti-corrosion plug is installed on the valve seat bolt.

[0047] By adopting the optimized technical features of the above method, the installation of each level of sealing rings and the tightening sequence of bolts are standardized, ensuring the airtightness and structural strength of the mating surface between the cylinder and the valve body, preventing high-pressure leakage or component loosening due to improper assembly, and ensuring the safe operation of the valve under 8.0 MPa conditions.

[0048] In summary, the technical solutions of the apparatus or method in this invention include at least one of the following technical effects that contribute to the prior art:

[0049] 1. Eliminating particle generation at its physical source for ultimate cleanliness: The "soft landing" buffer mechanism of this invention converts the high-speed kinetic energy of the valve when it closes into elastic potential energy and dissipates it, completely avoiding the rigid impact at the sealing interface in traditional valves. This reduces the number of particles generated by impact and friction by at least two orders of magnitude, controlling new particles ≥20Nm to ≤3Ea / ml, fully meeting the highest ISO Class 1 cleanliness requirements for semiconductors.

[0050] 2. Achieving ultra-low leakage rate under 8.0 MPa high pressure: An interference fit is formed between the double sealing flanges on the PTFE diaphragm and the grooves on the PEEK valve seat, supplemented by a raised sealing water line to concentrate stress, constructing a multi-stage redundant sealing system. This structure effectively resists the strong permeability of supercritical carbon dioxide. Helium gas chromatography-mass spectrometry (HGS) analysis shows that the leakage rate of its plastic sealing structure can be consistently below 5 x 10⁻⁶. -6 Pa·m³ / s, achieving "technical zero leakage" under high pressure.

[0051] 3. Ensuring a Metal-Free Flow Path and Long Service Life: All valve components in contact with the process fluid are made of carefully selected high-purity engineering plastics (PTFE / PEEK), completely eliminating the possibility of metal ion precipitation and ensuring the chemical purity of the process fluid (metal ion precipitation concentration less than 1ppt). Simultaneously, the "soft landing" mechanism significantly reduces the impact stress on the diaphragm. Combined with the optimized design of the diaphragm's flexible length, its mechanical fatigue life is significantly improved, easily exceeding 5 million switching cycles.

[0052] 4. Enhanced operational reliability and intelligent integration capabilities: The innovative impeller structure on the lower end face of the piston utilizes the driving airflow to generate anti-rotation torque, reducing the risk of loosening of the threaded connection between the piston and the diaphragm. Simultaneously, the integrated photoelectric switch provides precise on / off status feedback signals for the valve, facilitating integration into the equipment's main control PLC system to achieve automated closed-loop control and fault early warning of the process flow. Attached Figure Description

[0053] Figure 1 A three-dimensional schematic diagram of a pneumatic high-pressure valve for a semiconductor supercritical cleaning equipment is shown in an embodiment of the present invention;

[0054] Figure 2 An exploded view of the components of the pneumatic high-pressure valve in an embodiment of the present invention is shown.

[0055] Figure 3 A cross-sectional schematic diagram of the pneumatic high-pressure valve in an embodiment of the present invention is shown;

[0056] Figure 4 An exploded view of the cylinder assembly of the pneumatic high-pressure valve in an embodiment of the present invention is shown.

[0057] Figure 5 A schematic diagram illustrating the features of the cylinder body of the pneumatic high-pressure valve in an embodiment of the present invention;

[0058] Figure 6 A schematic diagram illustrating the features of the piston of the pneumatic high-pressure valve in an embodiment of the present invention;

[0059] Figure 7 A schematic diagram illustrating the features of the diaphragm of the pneumatic high-pressure valve in an embodiment of the present invention is shown. Figure 7 Parts (A) and (B) show the features of the membrane from different angles;

[0060] Figure 8 Draw Figure 3 Enlarged view of region A in the middle;

[0061] Figure 9 Draw Figure 8 Enlarged view of region B in the middle;

[0062] Figure 10 A schematic diagram illustrating the features of the valve seat of the pneumatic high-pressure valve in an embodiment of the present invention is shown;

[0063] Figure 11 A flowchart illustrating an assembly method for a pneumatic high-pressure valve used in a semiconductor supercritical cleaning equipment according to an embodiment of the present invention is shown.

[0064] Figure 12 Draw the corresponding Figure 11 Assembly diagram for step S1;

[0065] Figure 13 Draw the corresponding Figure 11 Assembly diagram for step S2;

[0066] Figure 14 Draw the corresponding Figure 11 Assembly diagram for step S3;

[0067] Figure 15 Draw the corresponding Figure 11 Assembly diagram for steps S4-S5.

[0068] Figure label:

[0069] 10. Cylinder top cover; 11. Air outlet; 12. Receiving cavity; 13. Top cover sealing ring;

[0070] 20. Cylinder block; 21. Elastic washer; 22. Intake port; 23. Piston chamber; 24. Center bore; 25. Center step;

[0071] 30. Piston; 30A. Piston body; 30B. Upper piston rod; 30C. Lower piston rod; 30D. Annular stepped surface; 30E. Impeller structure; 31. Upper piston seal ring; 31A. Upper sealing groove; 32. Piston body seal ring; 32A. Body sealing groove; 33. Lower piston seal ring; 33A. Lower sealing groove; 34. Normally closed outer spring; 35. Normally closed inner spring;

[0072] 40. Plastic diaphragm; 41. Sealing diaphragm section; 41A. First sealing flange; 41B. Second sealing flange; 41C. Sealing water line protrusion; 42. Valve core; 42A. Threaded section; 42B. Valve core platform;

[0073] 50. Plastic valve seat; 51. Valve seat sealing ring; 51A. Valve seat sealing groove; 52. Valve port; 53. Inlet flow channel; 54. Outlet flow channel; 55. First valve seat retaining groove; 56. Second valve seat retaining groove;

[0074] 60. Photoelectric switch; 61. Photoelectric switch bolt;

[0075] 71. Cylinder anti-corrosion plug; 72. Cylinder bolt; 73. Cylinder gasket; 74. Valve seat anti-corrosion plug; 75. Valve seat bolt; 76. Valve seat gasket. Detailed Implementation

[0076] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments for understanding the inventive concept of the present invention, and cannot represent all embodiments, nor are they interpreted as the only embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art under the premise of understanding the inventive concept of the present invention are within the scope of protection of the present invention.

[0077] The "soft landing" mentioned in the embodiments and variations of this invention refers to a specific method of valve closing action in this invention. It is not the "hard closing" of a traditional valve where the valve core directly impacts the valve seat with high-speed kinetic energy. Instead, through a pre-set, independent elastic buffer mechanism, most of the kinetic energy of the actuator (piston) is absorbed the instant before the valve core contacts the valve seat, thus achieving a gentle contact between the valve core and the valve seat at an extremely low speed to complete the seal. Its core lies in decomposing the closing process into two stages: "high-speed approach" and "low-speed compression," eliminating impact energy at its physical source and thus suppressing particle generation. The "sealing waterline" refers to one or more annular, tiny linear protrusions with a cross-sectional size much smaller than the main sealing flange, integrally formed on the lower surface of the sealing diaphragm of the plastic diaphragm. Its function is not to guide flow in the traditional sense, but rather as a "stress concentration structure." Under pre-tightening force, it generates extremely high local pressure through a very small contact area, acting like a wedge on the valve seat surface to form a highly reliable line seal, cutting off the microscopic leakage path of highly permeable media such as supercritical fluids. "Interference fit" refers to the dimensional relationship between the sealing flange of the plastic diaphragm and the groove of the plastic valve seat in this invention. Before assembly, the outer diameter of the flange is designed to be slightly larger than the inner diameter of the groove. During assembly, the elasticity of the PTFE material is used to "squeeze" the flange into the groove, ensuring that it remains under pressure after assembly, thereby generating continuous radial sealing pressure at the interface between the two. "Supercritical fluid" specifically refers to a state of matter where both temperature and pressure are above their critical point. In this application, it mainly refers to supercritical carbon dioxide, whose physical characteristics include no surface tension, high permeability, and high solubility, posing challenges to valve sealing and material compatibility far exceeding those of conventional fluids. It should be noted that if any directional indication (such as up, down, left, right, front, back, etc.) is involved in the embodiments of this invention, the directional indication is only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indication will also change accordingly. To facilitate a better understanding of the technical solution of this invention, the electric regulating valve of this invention will be described and explained in further detail below, but this should not be construed as limiting the scope of protection of this invention.

[0078] Figure 1 A three-dimensional schematic diagram of a pneumatic high-pressure valve for a semiconductor supercritical cleaning equipment is shown in an embodiment of the present invention; Figure 2 An exploded view of the components of the pneumatic high-pressure valve in an embodiment of the present invention is shown. Figure 3 A cross-sectional schematic diagram of the pneumatic high-pressure valve in an embodiment of the present invention is shown; Figure 4 An exploded view of the cylinder assembly of the pneumatic high-pressure valve in an embodiment of the present invention is shown. Figure 5 A schematic diagram illustrating the features of the cylinder body of the pneumatic high-pressure valve in an embodiment of the present invention; Figure 6A schematic diagram illustrating the features of the piston of the pneumatic high-pressure valve in an embodiment of the present invention; Figure 7 A schematic diagram illustrating the features of the diaphragm of the pneumatic high-pressure valve in an embodiment of the present invention is shown. Figure 7 Parts (A) and (B) show the features of the membrane from different angles; Figure 8 Draw Figure 3 Enlarged view of region A in the middle; Figure 9 Draw Figure 8 Enlarged view of region B in the middle; Figure 10 A schematic diagram illustrating the features of the valve seat of the pneumatic high-pressure valve in an embodiment of the present invention is shown.

[0079] A pneumatic high-pressure valve for semiconductor supercritical cleaning equipment is used in the semiconductor manufacturing industry's equipment supply chain. Specifically, it can be applied to the flow control of advanced supercritical carbon dioxide cleaning process equipment. The product application requirements of the pneumatic high-pressure valve include: withstanding the high pressure of 8.0 MPa that can be reached in the supercritical carbon dioxide cleaning process, a clean valve cavity with no dead zone, extremely close to zero leakage, and almost no particle and metal ion precipitation.

[0080] Reference Figure 1 and Figure 2 The pneumatic high-pressure valve for a semiconductor supercritical cleaning equipment disclosed in this embodiment of the invention includes: a cylinder assembly pre-assembled to form a driving and conducting function, a plastic diaphragm 40 controlled by the driving of the cylinder assembly to close the valve port 52, a plastic valve seat 50 that provides the valve port 52 and the flow channel connecting the valve port 52, and a photoelectric switch 60 mounted on the cylinder assembly.

[0081] Reference Figure 2 , Figure 3 and Figure 4 The cylinder assembly is mounted on the plastic valve seat 50. The cylinder assembly is pre-assembled with a cylinder cover 10, a cylinder body 20, and a piston 30.

[0082] Reference Figure 5The cylinder body 20 is mounted on the plastic valve seat 50, providing movement space for the piston 30 and guiding its reciprocating motion. The cylinder body 20 has a piston chamber 23 and a central hole 24 communicating with each other along its central axis. An air inlet 22 communicating with the piston chamber 23 is provided on the side wall of the cylinder body 20. A central step 25 is formed at the transition between the piston chamber 23 and the central hole 24, and an elastic washer 21 is provided on the central step 25. The elastic washer 21 is made of rubber or polyurethane and is used to buffer and decelerate the piston 30 when it moves downwards to contact the central step 25, thereby reducing the impact intensity between the plastic diaphragm 40 and the plastic valve seat 50 when the valve closes, and thus suppressing particle generation. A cylinder cover 10 is mounted on the cylinder body 20. The cylinder cover 10 and the cylinder body 20 are locked and fixed by cylinder bolts 72 and cylinder washers 73, and a cylinder anti-corrosion plug 71 is installed on the cylinder bolts 72. The cylinder cover 10 has an internal receiving cavity 12, and an air outlet 11 communicating with the receiving cavity 12 is opened on the side wall of the cylinder cover 10. The valve is installed in a circulating pipeline filled with ultrapure water (DIWater) in an ISO Class 3 clean environment. The cleanliness of the water in the pipeline is monitored online using a laser particle counter (capable of detecting particles ≥20Nm). The valve is continuously opened and closed 100,000 times, and the number of newly added particles per unit volume of liquid before and after the cycle is recorded. Experimental verification shows that the pneumatic high-pressure valve of this embodiment reduces the number of particles generated by impact and friction by at least two orders of magnitude, and can control the newly added particles ≥20Nm to ≤3Ea / ml, fully meeting the highest level of cleanliness requirements for semiconductors, ISO Class 1.

[0083] Reference Figure 6The piston 30 includes an integrally formed piston body 30A, an upper piston rod 30B, and a lower piston rod 30C. The upper piston rod 30B is connected to the upper end face of the piston body 30A, and the lower piston rod 30C is connected to the lower end face of the piston body 30A. The piston body 30A has a main sealing groove 32A, the upper piston rod 30B has an upper sealing groove 31A, and the lower piston rod 30C has a lower sealing groove 33A. The piston upper sealing ring 31, piston main sealing ring 32, and piston lower sealing ring 33 are pre-fitted into their respective upper sealing grooves 31A, main sealing groove 32A, and lower sealing groove 33A to seal the gaps between the piston 30 and the cylinder upper cover 10 and the cylinder body 20. The piston 30 is housed within the cylinder body 20. The piston body 30A is housed within the piston cavity 23. The upper piston rod 30B is housed in the receiving cavity 12, and a normally closed inner spring 35 and a normally closed outer spring 34 are sequentially sleeved on the upper piston rod 30B from the inside to the outside. The lower piston rod 30C extends from the piston cavity 23 into the central hole. The bottom end of the lower piston rod 30C has a threaded hole for installing a plastic diaphragm 40, and the lower piston rod 30C has an annular stepped surface 30D. The radial width of the annular stepped surface 30D matches the radial width of the elastic washer 21 (for example, the radial width of the annular stepped surface 30D is slightly larger than the radial width of the elastic washer 21). In the final stage of the pneumatic high-pressure valve closing, the annular stepped surface 30D acts as a contact area with the elastic washer 21 to achieve buffering and deceleration of the piston 30. During the closing process of the pneumatic high-pressure valve, the state of the driving air source connected to the air outlet 11 and the air inlet 22 changes from air intake to air exhaust. The normally closed inner spring 35 and the normally closed outer spring 34 push down to drive the plastic diaphragm 40 to close the valve port 52. At this time, in a conventional pneumatic high-pressure valve, particles may be generated between the plastic diaphragm 40 and the plastic valve seat 50 due to rapid impact. In order to meet the stringent requirement of almost no particles in semiconductor supercritical cleaning, this embodiment of the invention provides an elastic washer 21 on the central step 25, so that the piston 30 can be decelerated when it comes into contact with the elastic washer 21 during rapid downward movement, thereby suppressing the generation of particles.

[0084] In a preferred embodiment, an impeller structure 30E surrounding the lower piston rod 30C is provided on the lower end face of the piston body 30A. The impeller structure includes multiple radially and obliquely distributed blade grooves. During the process of driving gas flowing into the cylinder, the airflow impacts these blade grooves, generating a tangential torque that "locks" the piston 30 in the rotational position. This ingenious design effectively prevents the piston 30 from rotating unexpectedly during operation and prevents the plastic diaphragm 40 connected to the piston 30 from loosening, ensuring the long-term reliability of the pneumatic high-pressure valve seal.

[0085] Reference Figure 2 and Figure 3 A plastic diaphragm 40 is mounted on the bottom end of the piston 30, and the cylinder assembly and the diaphragm are mounted on the plastic valve seat 50. (See reference for details.) Figure 7 , Figure 8 and Figure 9The plastic diaphragm 40 is integrally molded from highly corrosion-resistant polytetrafluoroethylene (PTFE) material and mainly includes a sealing diaphragm portion 41 and a valve core 42 integrally disposed at its center. The valve core 42 is located at the center of the plastic diaphragm 40, having a lower valve core platform 42B and an upper threaded portion 42A. The valve core platform 42B is disposed at the valve port 52 of the plastic valve seat 50, and the threaded portion 42A is used to screw into a threaded hole at the bottom end of the lower piston rod 30C, so that the plastic diaphragm 40 is driven by the cylinder assembly to open or close the valve port 52. The sealing diaphragm portion 41 is a flexible disc-shaped body with a predetermined thickness and flexibility surrounding the valve core 42. In a preferred embodiment, the flexible length L1 of the sealing diaphragm portion 41 is less than or equal to 2.5 times the diaphragm thickness L2. On the lower surface of the sealing diaphragm portion 41, a first sealing flange 41A and a second sealing flange 41B are concentrically spaced outward from the center. The first sealing flange 41A and the second sealing flange 41B are respectively used to form a sealing interface by interference fit with the first valve seat groove 55 and the second valve seat groove 56 on the plastic valve seat 50. Both the first sealing flange 41A and the second sealing flange 41B are constructed with asymmetrical cross-sectional profiles. Specifically, both the first sealing flange 41A and the second sealing flange 41B have a beveled side near the valve core 42 and a straight side away from the valve core 42. The beveled side forms a gentle slope that guides and gradually compresses, facilitating the smooth sliding of the first sealing flange 41A and the second sealing flange 41B into the valve seat groove and avoiding installation damage. The straight side, opposite to the beveled side, can resist the leakage pressure of the internal fluid. The straight edge mates with the side of the valve seat groove, providing a nearly vertical, maximized pressure-bearing surface. This effectively blocks and withstands internal fluid pressure, thereby preventing the first sealing flange 41A and the second sealing flange 41B from deforming or being squeezed out under high pressure, thus improving the reliability of the seal. In a preferred embodiment, a sealing waterline protrusion 41C is provided between the first sealing flange 41A and the second sealing flange 41B, and between the first sealing flange 41A and the valve core 42. The sealing waterline protrusion 41C is located on the top surface of the plastic valve seat 50. When the plastic diaphragm 40 is pressed onto the plastic valve seat 50, the preload is highly concentrated at the top of the sealing waterline protrusion 41C, generating very high local pressure, further enhancing the pneumatic high-pressure valve's ability to withstand high pressure. The static external leakage rate is measured using a high-precision helium gas spectrometer by connecting the valve under test to an 8.0 MPa supercritical carbon dioxide pressure source. Subsequently, the valve underwent 100,000 high-pressure switching cycles (0 -> 8.0 MPa -> 0), and its leakage rate was measured again to evaluate its dynamic sealing performance and durability. Test data showed that the leakage rate of its plastic sealing structure remained consistently below 5 x 10⁻⁶.-6 Pa·m³ / s. The multi-stage seal in this embodiment of the invention is not a simple structural superposition. The sealing waterline achieves extremely high sealing specific pressure with minimal preload through the principle of "stress concentration." The interference fit of the double flange provides structural support and redundancy. These structures work synergistically to construct a highly reliable high-pressure sealing system under both static and dynamic conditions, far exceeding the performance of a single sealing structure, demonstrating the ingenuity of this invention.

[0086] Reference Figure 2 , Figure 3 and Figure 9 The plastic valve seat 50 is made of corrosion-resistant polyetheretherketone (PEEK) material and has a valve port 52 and an inlet flow channel 53 and an outlet flow channel 54 communicating with the valve port 52. The upper surface of the plastic valve seat 50 has a first valve seat groove 55, a second valve seat groove 56, and a valve seat sealing groove 51A. A valve seat sealing ring 51 is pre-fitted into the valve seat sealing groove 51A. The cylinder assembly and the plastic diaphragm 40 are mounted on the plastic valve seat 50. The cylinder body 20 and the plastic valve seat 50 are locked and fixed by valve seat bolts 75 and valve seat washers 76, and a valve seat anti-corrosion plug 74 is installed on the valve seat bolts 75. The valve seat sealing ring 51 is used to seal the gap between the cylinder body and the plastic valve seat 50. The first valve seat groove 55 and the second valve seat groove 56 are used to interference fit with the first sealing flange 41A and the second sealing flange 41B of the valve core 42, respectively, to form a sealing interface. The valve core platform 42B is located at the valve port 52, so that the plastic diaphragm 40 can be driven by the cylinder assembly to open or close the valve port 52.

[0087] Reference Figure 1 , Figure 2 and Figure 3The photoelectric switch 60 is mounted on the cylinder cover 10 via photoelectric switch bolts 61. The photoelectric switch 60 detects the position of the piston 30 to determine the on / off state of the pneumatic high-pressure valve, generates valve open and valve close signals, and feeds these signals back to the main control system (such as a PLC, DCS, or computer), thus forming a complete control closed loop. This is crucial for the programmed operation, fault diagnosis, and safety interlocking of semiconductor supercritical cleaning equipment. In a preferred embodiment, instead of the original photoelectric switch 60, a linear Hall effect displacement sensor can be integrated inside the cylinder cover 10. Simultaneously, a permanent magnet is embedded at the top of the upper piston rod 30B of the piston 30. In this way, the sensor can not only provide valve open and valve close signals but also output a continuous analog position signal of the piston in real time. This further enables the pneumatic high-pressure valve to have the possibility of coarse flow adjustment. More importantly, by monitoring the piston's position-time curve, the operating status of the valve can be accurately diagnosed; for example, it can determine whether the spring is fatigued, the air passage is blocked, or the seal is worn, providing a data basis for predictive maintenance of the equipment.

[0088] Figure 11 A flow block diagram illustrating an assembly method for a pneumatic high-pressure valve used in a semiconductor supercritical cleaning equipment, according to an embodiment of the present invention, is shown. (Refer to...) Figure 11 This invention also discloses an assembly method for a pneumatic high-pressure valve used in a semiconductor supercritical cleaning equipment, comprising steps S1 to S5. Steps S1 to S3 are key steps. Specifically, step S1 involves assembling a cylinder assembly, which includes a cylinder cover 10, a cylinder body 20, and a piston 30; step S2 involves installing a plastic diaphragm 40 onto the bottom end of the piston 30; step S3 involves installing the cylinder assembly and the plastic diaphragm 40 onto a plastic valve seat 50; step S4 involves placing an anti-corrosion plug on the cylinder assembly and the plastic valve seat 50; and step S5 involves installing a photoelectric switch 60 onto the cylinder assembly.

[0089] Figure 12 Draw the corresponding Figure 11 Assembly diagram for step S1. The operation of step S1 can be found in [reference needed]. Figure 12 (Refer to) Figure 2 , Figure 3 , Figure 4 and Figure 5Assemble the cylinder assembly. The cylinder assembly includes a cylinder top cover 10, a cylinder body 20, and a piston 30. In a preferred embodiment, step S1 specifically includes: fitting the piston upper sealing ring 31, piston body sealing ring 32, and piston lower sealing ring 33 into the corresponding sealing grooves of the piston 30; installing the elastic washer 21 on the center step 25 of the cylinder body 20; installing the piston 30 with the sealing rings installed into the cylinder body 20; fitting the normally closed outer spring 34 and normally closed inner spring 35 into the upper end of the piston 30; fitting the top cover sealing ring 13 into the sealing groove of the cylinder top cover 10; and locking the cylinder top cover 10 onto the cylinder body 20 using cylinder bolts 72 and cylinder washers 73.

[0090] The cylinder body 20 is mounted on the plastic valve seat 50, providing space for the piston 30 to move and guiding its reciprocating motion. The cylinder body 20 has a piston chamber 23 and a central hole 24 communicating with each other along its central axis. An air inlet 22 communicating with the piston chamber 23 is provided on the side wall of the cylinder body 20. A central step 25 is formed at the transition between the piston chamber 23 and the central hole 24, and an elastic washer 21 is provided on the central step 25. The elastic washer 21 is made of rubber or polyurethane and is used to buffer and decelerate the piston 30 when it moves downwards to contact the central step 25, thereby reducing the impact intensity between the plastic diaphragm 40 and the plastic valve seat 50 when the valve is closed, thus suppressing particle generation. The cylinder cover 10 is mounted on the cylinder body 20, and the cylinder cover 10 and the cylinder body 20 are locked and fixed by cylinder bolts 72 and cylinder washers 73. A cylinder anti-corrosion plug 71 is installed on the cylinder bolts 72. The cylinder cover 10 has an internal cavity 12, and an air outlet 11 communicating with the cavity 12 is provided on the side wall of the cylinder cover 10.

[0091] The piston 30 includes an integrally formed piston body 30A, an upper piston rod 30B, and a lower piston rod 30C. The upper piston rod 30B is connected to the upper end face of the piston body 30A, and the lower piston rod 30C is connected to the lower end face of the piston body 30A. The piston body 30A has a main sealing groove 32A, the upper piston rod 30B has an upper sealing groove 31A, and the lower piston rod 30C has a lower sealing groove 33A. The piston upper sealing ring 31, piston main sealing ring 32, and piston lower sealing ring 33 are pre-fitted into their respective upper sealing grooves 31A, main sealing groove 32A, and lower sealing groove 33A to seal the gaps between the piston 30 and the cylinder upper cover 10 and the cylinder body 20. The piston 30 is housed within the cylinder body 20. The piston body 30A is housed within the piston cavity 23. The upper piston rod 30B is housed in the receiving cavity 12, and a normally closed inner spring 35 and a normally closed outer spring 34 are sequentially sleeved on the upper piston rod 30B from the inside to the outside. The lower piston rod 30C extends from the piston cavity 23 into the central hole. The bottom end of the lower piston rod 30C has a threaded hole for installing a plastic diaphragm 40, and the lower piston rod 30C has an annular stepped surface 30D. The radial width of the annular stepped surface 30D matches the radial width of the elastic washer 21 (for example, the radial width of the annular stepped surface 30D is slightly larger than the radial width of the elastic washer 21). In the final stage of the pneumatic high-pressure valve closing, the annular stepped surface 30D acts as a contact area with the elastic washer 21 to achieve buffering and deceleration of the piston 30. During the closing process of the pneumatic high-pressure valve, the state of the driving air source connected to the air outlet 11 and the air inlet 22 changes from air intake to air exhaust. The normally closed inner spring 35 and the normally closed outer spring 34 push down to drive the plastic diaphragm 40 to close the valve port 52. At this time, in a conventional pneumatic high-pressure valve, particles may be generated between the plastic diaphragm 40 and the plastic valve seat 50 due to rapid impact. In order to meet the stringent requirement of almost no particles in semiconductor supercritical cleaning, this embodiment of the invention provides an elastic washer 21 on the central step 25, so that the piston 30 can be decelerated when it comes into contact with the elastic washer 21 during rapid downward movement, thereby suppressing the generation of particles.

[0092] Figure 13 Draw the corresponding Figure 11 Assembly diagram for step S2. The operation of step S2 can be found by referring to... Figure 13 (Refer to) Figure 7A plastic diaphragm 40 is installed at the bottom end of the piston 30. The externally threaded rod of the plastic diaphragm 40 is screwed into the external thread of the piston 30 end of the assembled cylinder assembly and tightened. The plastic diaphragm 40 is integrally molded from highly corrosion-resistant polytetrafluoroethylene (PTFE) material and mainly includes a sealing diaphragm portion 41 and a valve core 42 integrally located at its center. The valve core 42 is located at the center of the plastic diaphragm 40, having a lower valve core platform 42B and an upper threaded portion 42A. The valve core platform 42B is disposed at the valve port 52 of the plastic valve seat 50, and the threaded portion 42A is used to engage with the threaded hole at the bottom end of the lower piston rod 30C, so that the plastic diaphragm 40 is driven by the cylinder assembly to open or close the valve port 52. The sealing diaphragm portion 41 is a flexible disc-shaped body with a predetermined thickness and flexibility surrounding the valve core 42. In a preferred embodiment, the flexible length L1 of the sealing diaphragm portion 41 is less than or equal to 2.5 times the diaphragm thickness L2. A first sealing flange 41A and a second sealing flange 41B are concentrically spaced outwards from the center on the lower surface of the sealing diaphragm portion 41. The first sealing flange 41A and the second sealing flange 41B are respectively used to form a sealing interface with the first valve seat groove 55 and the second valve seat groove 56 on the plastic valve seat 50 through an interference fit. Both the first sealing flange 41A and the second sealing flange 41B are constructed with asymmetrical cross-sectional profiles. Specifically, both the first sealing flange 41A and the second sealing flange 41B have a beveled side near the valve core 42 and a straight side away from the valve core 42. The beveled side forms a gentle slope that guides and gradually compresses, facilitating the smooth sliding of the first sealing flange 41A and the second sealing flange 41B into the valve seat groove and avoiding installation damage. The straight side, opposite to the beveled side, can resist the leakage pressure of the internal fluid. The straight edge mates with the side of the valve seat groove, providing a nearly vertical, maximized pressure-bearing surface. This effectively blocks and withstands internal fluid pressure, thereby preventing the first sealing flange 41A and the second sealing flange 41B from deforming or being squeezed out under high pressure, thus improving the reliability of the seal. In a preferred embodiment, a sealing waterline protrusion 41C is provided between the first sealing flange 41A and the second sealing flange 41B, and between the first sealing flange 41A and the valve core 42. The sealing waterline protrusion 41C is located on the top surface of the plastic valve seat 50. When the plastic diaphragm 40 is pressed onto the plastic valve seat 50, the preload is highly concentrated at the top of the sealing waterline protrusion 41C, generating very high local pressure, further enhancing the pneumatic high-pressure valve's ability to withstand high pressure.

[0093] Figure 14 Draw the corresponding Figure 11 Assembly diagram for step S3. The operation of step S3 can be found in [reference needed]. Figure 14 (Refer to) Figure 8 and Figure 10 The cylinder assembly and the plastic diaphragm 40 are installed on the plastic valve seat 50. Specifically, the valve seat sealing ring 51 is inserted into the valve seat sealing groove of the plastic valve seat 50, the sealing flange of the plastic diaphragm 40 is aligned with the valve seat groove of the plastic valve seat 50 and pressed in, and finally the cylinder assembly and the plastic valve seat 50 are locked together using valve seat bolts 75 and valve seat washers 76. The plastic valve seat 50 is made of corrosion-resistant polyetheretherketone (PEEK) material and has a valve port 52 and an inlet flow channel 53 and an outlet flow channel 54 communicating with the valve port 52. The upper surface of the plastic valve seat 50 has a first valve seat groove 55, a second valve seat groove 56, and a valve seat sealing groove 51A, in which the valve seat sealing ring 51 is pre-fitted. The cylinder assembly and the plastic diaphragm 40 are mounted on the plastic valve seat 50. The cylinder body 20 and the plastic valve seat 50 are locked and fixed by valve seat bolts 75 and valve seat washers 76, and a valve seat anti-corrosion plug 74 is installed on the valve seat bolts 75. The valve seat sealing ring 51 is used to seal the gap between the cylinder body and the plastic valve seat 50. The first valve seat groove 55 and the second valve seat groove 56 are used to interference fit with the first sealing flange 41A and the second sealing flange 41B of the valve core 42, respectively, to form a sealing interface. The valve core platform 42B is located at the valve port 52, so that the plastic diaphragm 40 can be driven by the cylinder assembly to open or close the valve port 52.

[0094] Figure 15 Draw the corresponding Figure 11 Assembly diagrams for steps S4-S5. Steps S4-S5 can be referenced. Figure 15 (Refer to) Figure 2 Step S4 involves installing anti-corrosion plugs on the cylinder assembly and the plastic valve seat 50. Specifically, an anti-corrosion plug 71 is installed in the cylinder bolt hole, and an anti-corrosion plug 74 is installed in the valve seat bolt hole. Step S5 involves installing a photoelectric switch 60 on the top of the cylinder assembly. The photoelectric switch 60 is mounted on the cylinder cover 10. It is secured to the cylinder cover 10 using photoelectric switch bolts 61. The photoelectric switch 60 detects the position of the piston 30 to determine the on / off state of the pneumatic high-pressure valve, generates valve open and valve close signals, and feeds these signals back to the main control system (such as a PLC, DCS, or computer), thus forming a complete control closed loop. This is crucial for the programmed operation, fault diagnosis, and safety interlocking of semiconductor supercritical cleaning equipment.

[0095] The pneumatic high-pressure valve provided in the embodiments and variations of this invention has the following working principle: During valve opening, compressed air (typically 0.4-0.6 MPa) enters the lower part of the piston chamber 23 of the cylinder body 20 through the air inlet 22, pushing the piston body 30A upward against the resistance of the normally closed inner spring 35 and the normally closed outer spring 34. The piston 30 drives the valve core 42 of the connected plastic diaphragm 40 to move upward away from the valve port 52 of the plastic valve seat 50, opening the fluid passage. At this time, the photoelectric switch 60 detects that the piston 30 has moved upward to a predetermined position and outputs a valve position opening signal. During valve closing, the air source is switched to exhaust, and the spring force of the normally closed inner spring 35 and the normally closed outer spring 34 pushes the piston 30 downward. At the end of the closing stroke (for example, about 1 to 2 mm before the plastic diaphragm 40 contacts the plastic valve seat 50), the annular step surface 30D of the lower piston rod 30C of the piston 30 contacts the elastic washer 21 on the central step 25 of the cylinder body 20. The elastic washer 21 provides a reverse damping force, causing the piston 30 to decelerate rapidly. Subsequently, the piston 30 continues to descend at a low speed, causing the valve core 42 to seal the valve port 52. At this time, the photoelectric switch 60 detects the piston position and outputs a valve position closed signal.

[0096] The specific embodiments and variations provided by the present invention have the following corresponding technical effects to achieve a significant improvement over the prior art:

[0097] 1. Completely resolves the contradiction between high-pressure sealing and particle control: Traditional valves require forceful closure to withstand 8.0 MPa pressure, leading to particle splashing. This invention, through an "elastic gasket graded deceleration" mechanism, eliminates kinetic energy particles generated by impact without reducing the final sealing pressure, thus meeting ISO Class 1 cleanliness standards.

[0098] 2. An ultra-clean all-Teflon / PEEK flow path was constructed: the valve seat is made of PEEK and the diaphragm is made of PTFE. Combined with the unique "oblique side guidance + straight side pressure bearing" interference groove structure, not only is the precipitation of metal ions eliminated, but also the cold flow deformation of the PTFE diaphragm under high pressure is prevented, which greatly extends the service life of the valve in supercritical fluids.

[0099] 3. Achieved intelligent intrinsic safety control: integrated photoelectric feedback and anti-rotation impeller design. The impeller structure utilizes airflow as "energy" to convert it into "anti-loosening torque," preventing thread loosening accidents caused by piston rotation; the photoelectric switch provides real-time valve position status, and together with the anti-corrosion plug design, enables the valve to adapt to the humid and corrosive external environment of semiconductor plants.

[0100] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A pneumatic high pressure valve for supercritical cleaning of semiconductors, characterized in that The application relates to a plastic valve assembly, which comprises the following components: a cylinder assembly, which comprises a cylinder upper cover (10), a cylinder body (20) and a piston (30), the cylinder upper cover (10) is installed on the cylinder body (20), the cylinder body (20) is internally provided with a piston cavity (23) and a center hole (24) which are in communication with each other; wherein a center step (25) is formed at the transition of the piston cavity (23) and the center hole (24), an elastic gasket (21) is arranged on the center step (25), the piston (30) is accommodated in the piston cavity (23) and extends into the center hole (24) through the elastic gasket (21); a plastic diaphragm (40) which is provided with a sealing diaphragm part (41) and a valve core (42) arranged integrally in the center; the sealing diaphragm part (41) is sequentially provided with a first sealing flange (41A) and a second sealing flange (41B) outward along the center; the valve core (42) is provided with a threaded part (42A) at the upper part and a valve core platform (42B) at the lower part, and the threaded part (42A) is connected to the bottom end of the piston (30); a plastic valve seat (50) which is internally provided with a valve port (52), an inlet flow channel (53) and an outlet flow channel (54) which are in communication with the valve port (52), and the upper surface of the plastic valve seat (50) is sequentially provided with a first valve seat clamping groove (55) and a second valve seat clamping groove (56) outward along the center; the plastic valve seat (50) carries the cylinder assembly and the plastic diaphragm (40), the first sealing flange (41A) is installed in the first valve seat clamping groove (55), the second sealing flange (41B) is installed in the second valve seat clamping groove (56), and the valve core platform (42B) is located at the valve port (52); wherein the piston (30) is configured to move up and down to drive the valve core platform (42B) to seal or separate from the valve port (52), and the elastic gasket (21) is used for providing buffering during the downward movement of the piston (30) to reduce the impact intensity between the plastic diaphragm (40) and the plastic valve seat (50). The piston (30) comprises an integrally formed piston body (30A), an upper piston rod (30B) and a lower piston rod (30C), the upper piston rod (30B) is connected to the upper end face of the piston body (30A), and the lower piston rod (30C) is connected to the lower end face of the piston body (30A); the cylinder upper cover (10) is provided with a containing cavity (12); the piston body (30A) is accommodated in the piston cavity (23), and the lower end face of the piston body (30A) is provided with an impeller structure (30E) surrounding the lower piston rod (30C), the impeller structure (30E) is used to generate tangential torque under the action of the intake airflow to inhibit the rotation of the piston (30); the upper piston rod (30B) is accommodated in the containing cavity (12), and the upper piston rod (30B) is sequentially sleeved with a normally closed inner spring (35) and a normally closed outer spring (34) from inside to outside; the lower piston rod (30C) extends into the center hole from the piston cavity (23), the bottom end of the lower piston rod (30C) is provided with a threaded hole for mounting a plastic diaphragm (40), and the lower piston rod (30C) has an annular stepped surface (30D); the radial width of the annular stepped surface (30D) matches the radial width of the elastic washer (21), so as to contact the elastic washer (21) during the downward movement of the piston (30), so as to slow down the piston (30).

2. The pneumatic high pressure valve according to claim 1, characterized in that The material of the plastic diaphragm (40) is PTFE, wherein the flexible length of the sealing diaphragm part (41) of the plastic diaphragm (40) is less than or equal to 2.5 times the thickness of the diaphragm; the material of the plastic valve seat (50) is PEEK.

3. The pneumatic high pressure valve according to claim 1, characterized in that The sealing diaphragm part (41) is further provided with a sealing water line protrusion (41C) between the first sealing flange (41A) and the second sealing flange (41B) and between the first sealing flange (41A) and the valve core (42), and the sealing water line protrusion (41C) is located above the contact plane of the plastic valve seat (50) and the sealing diaphragm part (41).

4. The pneumatic high pressure valve according to claim 3, characterized in that The first sealing flange (41A) is installed in the first valve seat clamping groove (55) by interference fit, and the second sealing flange (41B) is installed in the second valve seat clamping groove (56) by interference fit; wherein the first sealing flange (41A) and the second sealing flange (41B) both have a beveled side close to the valve core (42) and a straight side away from the valve core (42); the beveled side is used for guiding installation; the straight side opposite to the beveled side is used for blocking fluid pressure.

5. The pneumatic high pressure valve according to claim 1, characterized in that The piston body (30A) is provided with a piston body sealing ring (32), the upper piston rod (30B) is provided with a piston upper sealing ring (31), and the lower piston rod (30C) is provided with a piston lower sealing ring (33), and the piston body sealing ring (32), the piston upper sealing ring (31) and the piston lower sealing ring (33) are used for sealing the gap between the piston (30) and the cylinder head (10) and the cylinder block (20); the plastic valve seat (50) is provided with a valve seat sealing ring (51), and the valve seat sealing ring (51) is used for sealing the gap between the cylinder block (20) and the plastic valve seat (50); the cylinder head (10) and the cylinder block (20) are locked through a cylinder bolt (72) and a cylinder washer (73), and the cylinder bolt (72) is provided with a cylinder anticorrosion plug (71); the plastic valve seat (50) and the cylinder block (20) are locked through a valve seat bolt (75) and a valve seat washer (76), and the valve seat bolt (75) is provided with a valve seat anticorrosion plug (74).

6. The pneumatic high pressure valve according to any one of claims 1 to 5, characterized in that Further comprising: A photoelectric switch (60) is installed on the cylinder head (10) and is used for detecting the position of the piston (30) to determine the on-off state of the pneumatic high-pressure valve and generate a valve position opening signal and a valve position closing signal.

7. A method of assembling a pneumatic high pressure valve for semiconductor supercritical cleaning, characterized by, The following steps are included: S1, assemble the cylinder assembly, the cylinder assembly includes a cylinder head (10), a cylinder block (20) and a piston (30), the cylinder head (10) is installed on the cylinder block (20), and the cylinder block (20) is provided with a piston cavity (23) and a center hole (24) which are in communication with each other; wherein the transition of the piston cavity (23) and the center hole (24) forms a center step (25), the center step (25) is provided with an elastic washer (21), the piston (30) is accommodated in the piston cavity (23) and extends into the center hole (24) through the elastic washer (21); the piston (30) includes an integrally formed piston body (30A), an upper piston rod (30B) and a lower piston rod (30C), the upper piston rod (30B) is connected to the upper end face of the piston body (30A), and the lower piston rod (30C) is connected to the lower end face of the piston body (30A); the cylinder head (10) is provided with a containing cavity (12); S2, install a plastic diaphragm (40) at the bottom end of the piston (30), the plastic diaphragm (40) has a sealing diaphragm part (41) and a valve core (42) integrally arranged at the center; the sealing diaphragm part (41) is sequentially provided with a first sealing flange (41A) and a second sealing flange (41B) outward along the center; the valve core (42) has a threaded part (42A) at the upper part and a valve core platform (42B) at the lower part, and the threaded part (42A) is connected to the bottom end of the piston (30); S3, install the cylinder assembly and the plastic diaphragm (40) on a plastic valve seat (50), the plastic valve seat (50) is internally provided with a valve port (52), an inlet flow channel (53) and an outlet flow channel (54) communicated with the valve port (52), and a first valve seat clamping groove (55) and a second valve seat clamping groove (56) are sequentially arranged on the upper surface of the plastic valve seat (50) along the center outward; the plastic valve seat (50) carries the cylinder assembly and the plastic diaphragm (40), the first sealing flange (41A) is installed in the first valve seat clamping groove (55), the second sealing flange (41B) is installed in the second valve seat clamping groove (56), and the valve core platform (42B) is located at the valve port (52); wherein the piston (30) is configured to move up and down to drive the valve core platform (42B) to seal or separate from the valve port (52), and the elastic washer (21) is used to provide buffering during the downward movement of the piston (30) to reduce the impact strength between the plastic diaphragm (40) and the plastic valve seat (50); In step S1, the piston body (30A) is accommodated in the piston cavity (23), and the lower end surface of the piston body (30A) is provided with an impeller structure (30E) surrounding the lower piston rod (30C); the upper piston rod (30B) is accommodated in the containing cavity (12), and the upper piston rod (30B) is sequentially sleeved with a normally closed inner spring (35) and a normally closed outer spring (34) from inside to outside; the lower piston rod (30C) extends into the center hole from the piston cavity (23), the bottom end of the lower piston rod (30C) is provided with a threaded hole for installing a plastic diaphragm (40), and the lower piston rod (30C) has an annular stepped surface (30D); wherein the radial width of the annular stepped surface (30D) matches the radial width of the elastic washer (21), which is used to contact the elastic washer (21) during the downward movement of the piston (30) to slow down the piston (30).

8. The method of assembly of claim 7, wherein, Also includes: Step S4, set a corrosion-proof plug on the cylinder assembly and the plastic valve seat (50); Step S5, install a photoelectric switch (60) on the cylinder assembly; wherein the photoelectric switch (60) is installed on the cylinder upper cover (10), which is used to detect the position of the piston (30) to determine the opening and closing state of the pneumatic high-pressure valve, and generate a valve position opening signal and a valve position closing signal.

9. The method of assembly of claim 7, wherein, In step S3, the first sealing flange (41A) is installed in the first valve seat clamping groove (55) by interference fit, and the second sealing flange (41B) is installed in the second valve seat clamping groove (56) by interference fit; wherein the first sealing flange (41A) and the second sealing flange (41B) both have a beveled side close to the valve core (42) and a straight side away from the valve core (42); the beveled side is used for guiding installation; the straight side opposite to the beveled side is used for blocking fluid pressure.

10. The method of assembly of claim 9, wherein, In step S1, the piston body (30A) is provided with a piston body sealing ring (32), the upper piston rod (30B) is provided with a piston upper sealing ring (31), and the lower piston rod (30C) is provided with a piston lower sealing ring (33), which are used to seal the gap between the piston (30) and the cylinder head (10) and the cylinder body (20); the cylinder head (10) and the cylinder body (20) are locked by cylinder bolts (72) and cylinder gaskets (73); In step S3, the plastic valve seat (50) is provided with a valve seat sealing ring (51), which is used to seal the gap between the cylinder body (20) and the plastic valve seat (50); the plastic valve seat (50) and the cylinder body (20) are locked by valve seat bolts (75) and valve seat gaskets (76); In step S4, a cylinder corrosion prevention plug (71) is installed on the cylinder bolt (72), and a valve seat corrosion prevention plug (74) is installed on the valve seat bolt (75).

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