A dead zone free diaphragm valve for semiconductor high purity media

Abstract

This invention relates to the field of ultra-high purity fluid control technology in semiconductor manufacturing, and discloses a dead-zone-free diaphragm valve for high-purity semiconductor media. The valve adopts a modular architecture, including a valve body module, an integrated flow channel liner module, a diaphragm sealing assembly module, a valve stem drive module, a position sensing feedback module, an in-situ purging interface module, and a differential pressure balance channel module. Dead zones in the valve cavity are eliminated through a fully streamlined, uniform cross-section flow channel liner. A contour-adaptive diaphragm and a hyperboloid sealing edge form a surface seal with tangential inner surfaces and no stagnant cavities. Combined with micron-level position feedback, precise deformation control is achieved. A matching tangential swirl purging and differential pressure balance structure enables efficient online cleaning. This invention completely solves the problems of high-purity media residue, particle growth, and cross-contamination, and is suitable for ultra-high purity media transportation scenarios in advanced wafer manufacturing processes.

Description

Technical Field

[0001] This invention belongs to the field of ultra-high purity fluid control technology in semiconductor manufacturing, specifically a dead-zone-free diaphragm valve for semiconductor high-purity media. Background Technology

[0002] In the core processes of semiconductor wafer manufacturing, such as etching, cleaning, and thin film deposition, the delivery accuracy and cleanliness of ultra-high purity chemical liquids and special electronic gases directly determine the wafer yield and device electrical performance. Diaphragm valves, with their advantages of complete isolation between the medium and the drive mechanism and no external leakage, have become the core control element of high-purity medium delivery pipelines.

[0003] Existing semiconductor-grade diaphragm valves have the following prominent technical defects in practical applications;

[0004] 1. The flow channel structure has an inherent dead zone; traditional valve bodies mostly use cast or machined right-angled cavities, and there are steps, sharp corners and abrupt changes in cross-section at the connection between the flow channel and the valve cavity. When the medium flows through, a low-speed vortex stagnation zone is formed. Long-term operation will cause crystal particles to precipitate, microorganisms to grow or residual previous media to remain in the dead zone, and the risk of cross-contamination when switching media is extremely high. According to industry tests, the residual volume of the dead zone of conventional diaphragm valves can reach 0.3-0.8mL, which cannot meet the ppb-level cleanliness requirements of advanced processes.

[0005] Second, there is a residual cavity in the sealing structure; the conventional planar diaphragm and valve seat edge are in line contact seal, and an annular cavity is formed between the inner side of the sealing edge and the lower surface of the diaphragm. When the valve is closed, the medium is sealed in the cavity and cannot be carried away by the mainstream medium. Each opening and closing action will cause particles to fall off and the medium to become contaminated.

[0006] Third, insufficient opening control accuracy; most existing diaphragm valves are open-loop point-position control, which cannot sense the actual deformation of the diaphragm. After long-term operation, the diaphragm will creep and age, which will cause the actual opening to deviate from the design value. The dead zone volume gradually increases with the aging of the diaphragm, and the online cleaning effect is uncontrollable.

[0007] Fourth, the online cleaning efficiency is low; most existing cleaning methods are forward flushing, which makes it difficult to effectively replace the stagnant media in the dead zone. This requires long-term, high-flow rinsing, which not only wastes high-purity media but also significantly reduces equipment uptime.

[0008] To address the aforementioned issues, existing technologies have failed to systematically solve the dead zone problem from four dimensions: flow channel structure, sealing form, control precision, and cleaning method, and are therefore unable to meet the ultra-high cleanliness requirements of advanced semiconductor manufacturing processes. Summary of the Invention

[0009] In order to overcome the shortcomings of the prior art, the present invention provides a dead-zone-free diaphragm valve for high-purity semiconductor media, which effectively solves the systemic problems of existing diaphragm valves in four dimensions: flow channel structure, sealing form, control accuracy and cleaning method.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a dead-zone-free diaphragm valve for high-purity semiconductor media, comprising a valve body base module, an integrated flow channel lining module, a diaphragm sealing assembly module, a valve stem drive module, a position sensing feedback module, an in-situ purging interface module, a differential pressure balance channel module, and an actuator control module.

[0011] The valve body base module serves as the structural load-bearing entity, providing installation references and sealing interfaces for the other modules. The integrated flow channel liner module is embedded in the inner cavity of the valve body base, employing a fully streamlined, uniform cross-section design with no right angles, steps, or abrupt changes in cross-section, eliminating dead zones in the flow channel morphology. The diaphragm sealing assembly module is located at the top sealing port of the liner, with the lower surface contour of the diaphragm perfectly matching the liner sealing surface. When closed, it forms a full-circumferential seal, with the inner side of the seal tangentially connected to the inner wall of the flow channel, completely eliminating any residual sealing cavities. The valve stem drive module is used to output a linear... The displacement drives the diaphragm to generate elastic deformation, thereby achieving on / off switching and adjustment. The position sensing feedback module collects the valve stem's micron-level displacement in real time, accurately feeding back the actual deformation of the diaphragm. The in-situ purging interface module is connected along the tangent of the flow channel, generating a spiral vortex to sweep across the entire inner wall and sealing surface of the flow channel, achieving efficient online cleaning. The differential pressure balance channel module connects the upper cavity of the diaphragm and the inlet flow channel, balancing the static pressure difference on both sides of the diaphragm, reducing the driving load and decreasing the diaphragm stress. The actuator control module forms a closed-loop control based on position feedback, achieving precise adjustment of the opening degree and automatic compensation for diaphragm creep.

[0012] Furthermore, the integrated flow channel liner module consists of an inlet straight section, a central gradually expanding sealing section, and an outlet straight section. The sections are smoothly transitioned by a large-radius circular arc. The cross-sectional area of ​​the flow channel remains constant along the flow direction. CFD fluid simulation optimization ensures that there is no low-speed vortex region.

[0013] Furthermore, the top sealing edge of the central gradually expanding sealing section adopts a hyperbolic arc surface structure, with smooth arcs in both the axial and radial directions. The inner side of the sealing surface is connected to the tangent of the inner wall of the flow channel, without any depressions or steps.

[0014] Furthermore, the diaphragm sealing assembly adopts a three-layer composite structure, with an inner layer of high-purity modified PTFE diaphragm, a middle layer of metal elastic support, a central connecting seat for fixed connection with the valve stem, and the edges of the diaphragm being pressed and fixed by a pressure ring.

[0015] Furthermore, the position sensing feedback module adopts a non-contact magnetostrictive or laser displacement sensor with a resolution of not less than 1 micrometer, and is equipped with a signal conditioning unit and a calibration storage unit, and has a built-in creep compensation algorithm.

[0016] Furthermore, the in-situ purging interface module consists of a purging connector, a high-purity one-way valve, and a swirl guide channel assembly. The guide channels are evenly distributed along the circumference of the flow channel, and the purging medium enters tangentially to form a spiral flow field.

[0017] Furthermore, the differential pressure balance channel module incorporates a filter damping unit and a pressure buffer chamber. The filter unit blocks particles from entering the drive chamber, and the buffer chamber attenuates pressure fluctuations.

[0018] Furthermore, the actuator control module adopts a PID closed-loop control algorithm, which can accurately control the fully open, fully closed and arbitrary intermediate opening degrees, and has creep compensation, fault warning and communication functions.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] (1) Thorough elimination of dead zone: Through the combination design of the streamlined equal cross-section flow channel lining and the tangential surface sealing structure, the dead zone of the flow channel structure and the residual cavity of the seal are eliminated at the same time. The overall dead zone residual volume of the valve is reduced to less than 0.02mL, which is more than 90% lower than that of traditional diaphragm valves, thus avoiding media retention and particle growth from the source.

[0021] (2) Higher control precision: Micron-level non-contact position detection combined with closed-loop control can achieve an opening control precision of ±1μm, which can compensate for deviations caused by diaphragm creep and thermal expansion and contraction in real time, ensuring that the dead zone volume remains stable and does not increase after long-term operation, and the cleaning effect can be repeated.

[0022] (3) Improved cleaning efficiency: The tangential swirling purging method causes the cleaning medium to spiral forward along the inner wall, covering the entire flow channel surface and sealing surface, reducing the cleaning time by more than 65%, reducing the consumption of high-purity media by 70%, and greatly improving the equipment utilization rate.

[0023] (4) Extended service life: The differential pressure balance design makes the static pressure on the upper and lower sides of the diaphragm basically equal. The drive mechanism only needs to overcome the elastic force of the diaphragm, and the output force is reduced by more than 60%. At the same time, the diaphragm stress is greatly reduced, and the service life is more than twice that of the traditional structure.

[0024] (5) Good maintenance convenience: The modular design is adopted, and the flow channel lining and diaphragm assembly are independent replaceable units. There is no need to disassemble the entire pipeline during maintenance, which shortens the replacement time by 80%. The valve body base can be reused, reducing the total life cycle cost.

[0025] (6) Strong adaptability to working conditions: By changing the lining and diaphragm components of different materials, it can be adapted to various media such as ultra-high purity chemical liquids and special electronic gases, and supports various working modes such as normally closed, normally open, and adjustable, covering most high-purity media transportation scenarios in semiconductor manufacturing. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0027] In the attached diagram:

[0028] Figure 1 This is a block diagram showing the overall modular architecture and connection relationships of the present invention;

[0029] Figure 2 A block diagram of the internal flow channel structure of the integrated flow channel lining module;

[0030] Figure 3 A block diagram of the layered composite structure of the diaphragm sealing assembly module;

[0031] Figure 4 A block diagram showing the internal composition and flow of the in-situ purging interface module;

[0032] Figure 5 This is a block diagram showing the signal connection between position sensing feedback and actuator control.

[0033] Figure 6 This is a block diagram of the internal structure of the differential pressure balancing channel module;

[0034] In the diagram: 1. Valve body base module; 2. Integrated flow channel lining module; 21. Inlet straight section; 22. Central gradually expanding sealing section; 23. Outlet straight section; 3. Diaphragm sealing assembly module; 31. Reinforced PTFE diaphragm layer; 32. Metal elastic support layer; 33. Central connecting seat; 4. Valve stem drive module; 5. Position sensing feedback module; 51. Non-contact displacement sensor; 52. Signal conditioning unit; 53. Calibration storage unit; 6. In-situ purge interface module; 61. Purge inlet connector; 62. High-purity check valve unit; 63. Swirl flow guide channel group; 7. Differential pressure balance channel module; 71. Filter damping unit; 72. Pressure buffer chamber; 8. Actuator control module; 9. Medium inlet port; 10. Medium outlet port. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] This embodiment describes a normally closed pneumatic diaphragm valve with no dead zone, suitable for transporting ultra-high purity chemical liquids. It has a nominal diameter of DN15, a rated working pressure of 0.7MPa, and is applicable to media including semiconductor process chemicals such as hydrofluoric acid, ammonia, isopropanol, and photoresist developer. It is mainly used in media transport pipelines for wafer cleaning and wet etching processes.

[0038] The valve body base module 1 is made of 316L austenitic stainless steel forging blank, integrally milled by a five-axis linkage machining center, and subjected to solution treatment and passivation treatment. After electrolytic polishing, the surface roughness Ra≤0.8μm, and the flatness of the inner cavity mounting reference surface≤0.02mm. The left and right ends of the valve body base module 1 are respectively machined with a medium inlet port 9 and a medium outlet port 10. The ports adopt a 1 / 2-inch VCR face seal connection structure, and the end face sealing surface is ultra-precision ground with a flatness ≤0.002mm to ensure no external leakage of high-purity media. The valve body base module 1... The inner cavity has an annular positioning step machined in the middle, and the step surface is provided with an annular sealing groove with a rectangular cross section. A high-purity perfluoroether rubber O-ring is built in to achieve radial static sealing between the lining and the valve body. The top of the valve body has a drive module mounting flange machined, which is fastened to the valve stem drive module 4 by 8 internal hexagonal stainless steel bolts. The flange surface has two symmetrically distributed positioning pin holes to ensure that the assembly coaxiality is ≤0.03mm. The side wall on the inlet side of the valve body has a purge interface mounting hole machined, and the top side wall has a process hole for differential pressure balance channel. The end of the process hole is sealed with a stainless steel ball sealing weld.

[0039] The integrated flow channel lining module 2 is made of high-purity PFA (fusible polytetrafluoroethylene) raw material and is formed by a precision injection molding machine in a 100,000-level cleanroom. After molding, it is annealed at 200℃ for 4 hours to eliminate internal stress. The inner surface is fluid polished, and the final roughness Ra≤0.05μm, with no visible scratches or pits. The lining has an axisymmetric structure and is divided into an inlet straight section 21, a central gradually expanding sealing section 22, and an outlet straight section 23 along the medium flow direction. In this embodiment, the inner diameter of the inlet straight section 21 and the outlet straight section 23 are both 15mm, and the lengths are 20mm and 18mm, respectively. The left end of the inlet straight section 21 is provided with an outwardly flanged positioning platform, which is inserted into the positioning groove at the valve body inlet end to prevent axial movement of the lining. The inlet straight section 21 and the central gradually expanding sealing section 22 are smoothly transitioned by an R8mm concave arc. The central gradually expanding sealing section 22 gradually expands in diameter towards the top, with a maximum inner diameter of 24mm. The sealing edge adopts a hyperbolic arc surface structure, with an axial section arc radius of 12mm and a radial section arc radius of 15mm, forming a continuous, uniformly wide sealing band of 2mm. The central gradually expanding sealing section 22 and the outlet straight section 23 are smoothly transitioned by an arc with the same parameters, and the cross-sectional area of ​​the flow channel remains constant throughout. The flow channel profile has been optimized by CFD fluid dynamics simulation. In the flow velocity range of 0.5m / s-3m / s, there is no low-speed vortex zone in the flow channel, and the medium flow velocity uniformity deviation is less than 5%, completely eliminating the dead zone. The outer circular surface of the lining is provided with an annular positioning boss, which is interference-fitted with the inner cavity positioning step of the valve body base module 1. The interference is 0.05mm. During assembly, a heat fitting process is adopted. The valve body is heated to 80℃ and then pressed into the lining. After cooling, it fits tightly without relative displacement. The inlet and outlet end faces of the lining are both machined with a 15° chamfer, which smoothly connects with the inner wall of the valve body port, and the step misalignment is ≤0.02mm.

[0040] The diaphragm sealing assembly module 3 is located at the top opening of the integrated flow channel liner module 2. From bottom to top, it consists of a reinforced polytetrafluoroethylene (PTFE) diaphragm layer 31, a metal elastic support layer 32, and a central connecting seat 33. The three layers are hot-pressed together and riveted to the center to form an integral structure. The reinforced PTFE diaphragm layer 31 has a thickness of 0.8 mm and is made of modified PTFE material filled with 20% glass fiber to improve creep resistance and wear resistance. The lower surface is mirror-polished with a roughness Ra≤0.02μm. The lower surface contour of the diaphragm layer perfectly matches the hyperboloidal surface of the top surface of the central gradually expanding sealing section 22. In the closed state, the two form a full-circuit surface contact seal. The inner edge of the sealing surface is connected to the tangent of the inner wall of the flow channel, with no recessed cavities, completely eliminating sealing dead angles. The metal elastic support layer 32 has a thickness of... A 0.3mm Hastelloy C276 thin-shell stamped sheet is attached to the upper surface of the diaphragm layer, providing uniform elastic recovery force to the diaphragm and dispersing the concentrated load on the valve stem to avoid excessive local stress on the diaphragm. The central connecting seat 33 is made of 316L stainless steel and is fastened to the diaphragm layer and support layer by riveting at the bottom. It has an M4 internal thread hole in the center, which is threaded to the valve stem end of the valve stem drive module 4 and is equipped with anti-loosening adhesive for locking. The outer edge of the diaphragm assembly is pressed and fixed to the top positioning step of the integrated flow channel liner module 2 by a stainless steel annular pressure ring. The pressure ring is locked by 6 circumferentially distributed fastening bolts. The clamping force is precisely calculated to ensure reliable sealing and no permanent deformation of the diaphragm edge. A uniform gap is left between the inner wall of the pressure ring and the deformation area of ​​the diaphragm to avoid interfering with the vertical deformation of the diaphragm.

[0041] The valve stem drive module 4 adopts a single-acting pneumatic piston drive structure and is installed at the upper flange of the valve body base module 1. The drive module includes a cylinder body, piston assembly, return spring assembly, guide sleeve, and valve stem. The cylinder diameter is 40mm, the rated drive air pressure is 0.5MPa, and the piston is sealed with a PTFE guide ring, resulting in low frictional resistance. The return spring assembly uses three circumferentially distributed stainless steel springs to provide stable return force, ensuring automatic valve closure in case of air loss. The valve stem is made of 316L stainless steel, heat-treated, and hard chrome plated. It has a clearance fit with the guide sleeve, and the guide length is more than three times the valve stem diameter to ensure linearity of movement. The lower end of the valve stem passes through the guide hole in the center of the pressure ring and is threaded to the center connecting seat 33. A dustproof ring is provided at the guide hole to prevent external particles from entering the drive chamber. The upper limit position of the valve stem is adjusted by the limit nut, corresponding to the fully open state of the valve. The lower limit position is determined by the calibrated fully closed displacement, corresponding to the fully closed state of the valve.

[0042] The position sensing feedback module 5 is mounted on the side mounting bracket of the valve stem drive module 4, and includes a non-contact displacement sensor 51, a signal conditioning unit 52, and a calibration storage unit 53. The non-contact displacement sensor 51 is a magnetostrictive displacement sensor with a detection range of 20mm, a resolution of 0.5μm, and a repeatability of ±1μm. A permanent magnet assembly is mounted on the top of the valve stem, with the magnet arranged parallel to the sensor sensing rod, enabling non-contact detection of the valve stem's real-time displacement. The signal conditioning unit 52 converts the raw pulse signal output by the sensor into a standard 4-20mA analog signal and an RS485 digital signal, which are then transmitted to the actuator control module 8. The calibration storage unit 53 uses an industrial-grade Flash memory chip, pre-stores the factory-calibrated displacement-opening curve, and incorporates a diaphragm creep compensation algorithm. This algorithm automatically corrects the fully closed position reference based on the cumulative operating time and number of switching cycles, compensating for the sealing stroke loss caused by diaphragm creep, and ensuring stable sealing pressure and no increase in dead zone volume after long-term operation.

[0043] The in-situ purge interface module 6 is located on the inlet side of the valve body base module 1. Along the purge medium flow direction, it sequentially includes a purge inlet connector 61, a high-purity check valve unit 62, and a swirl guide channel group 63. The purge inlet connector 61 uses a 1 / 4-inch VCR interface, connected to an external high-purity nitrogen or ultrapure water cleaning pipeline. The connector material is 316L stainless steel, electrolytically polished. The high-purity check valve unit 62 uses a PFA valve seat and a fluoroplastic valve core, with an opening pressure of 0.05 MPa, which can prevent process... The reverse flow of the medium into the purging pipeline causes cross-contamination; the swirl guide channel group 63 contains a total of 3 guide channels, which are evenly distributed along the circumference of the straight section 21 at the inlet. The outlet axis of the guide channel forms a 35° angle with the axial direction of the flow channel and is arranged along the tangential direction of the inner wall of the flow channel. During purging, the high-pressure cleaning medium enters the flow channel tangentially through the guide channel, forming a spiral swirling flow field. The flow field flows closely against the inner wall, which can effectively peel off particles and residual media attached to the wall and sealing surface, and the cleaning coverage reaches 100%.

[0044] The differential pressure balancing channel module 7 is located within the internal wall of the valve body base module 1. The channel has a diameter of 2mm, with one end connected to the drive chamber above the diaphragm sealing assembly module 3 and the other end connected to the inlet side flow channel of the integrated flow channel lining module 2. Inside the channel, along the medium flow direction, a filter damping unit 71 and a pressure buffer chamber 72 are sequentially arranged. The filter damping unit 71 uses a sintered stainless steel filter element with a filtration accuracy of 0.2μm, which can prevent particles in the medium from entering the drive chamber, avoiding particle abrasion of the diaphragm's upper surface and the drive components. The pressure buffer chamber 72 is a cylindrical expanded cavity with a diameter of 6mm and a length of 8mm, with a volume of approximately 0.23mL. It can effectively attenuate inlet pressure fluctuations and reduce the impact of pressure shocks on diaphragm deformation. The differential pressure balancing channel ensures that the static pressure on both sides of the diaphragm is essentially equal. The valve stem drive only needs to overcome the diaphragm's elastic force and sealing specific pressure, significantly reducing the drive gas source pressure requirements and simultaneously reducing the alternating stress on the diaphragm, thus extending its service life.

[0045] The actuator control module 8 is installed in the electrical box on top of the valve. It uses an industrial-grade 32-bit microcontroller as its core. The signal input terminal is electrically connected to the position sensing feedback module 5, and the control output terminal is electrically connected to the solenoid valve of the valve stem drive module 4. The actuator control module 8 adopts an incremental PID closed-loop control algorithm. After receiving the real-time displacement feedback signal, it precisely adjusts the output air pressure of the solenoid valve to control the stroke and speed of the valve stem, so that the diaphragm can be stably in a fully open, fully closed, or any intermediate opening position. The control module has multiple built-in working modes, including on / off mode, proportional regulation mode, cleaning mode, etc. It also has functions such as diaphragm life warning, abnormal opening alarm, and sensor fault diagnosis. It supports Modbus communication protocol to connect to the factory control system.

[0046] The complete working process of this embodiment is as follows:

[0047] Fully open state: Under the action of the return spring, the valve stem drive module 4 drives the valve stem to the highest position, and the diaphragm sealing assembly module 3 springs up accordingly. The lower surface of the diaphragm is basically flush with the inner wall of the top of the flow channel, and the flow channel is a complete smooth tube. The medium enters from the medium inlet port 9, flows out from the medium outlet port 10 through the inlet straight section 21, the central gradually expanding sealing section 22, and the outlet straight section 23. The flow rate is uniform throughout the process, with no dead zones.

[0048] Valve closing process: The actuator control module 8 outputs a valve closing signal, the solenoid valve is turned on to drive the air pressure, the piston pushes the valve stem downward, and the center of the diaphragm undergoes elastic deformation downward; the position sensing feedback module 5 collects the valve stem displacement in real time. When the displacement reaches the calibrated full-close value, the actuator control module 8 cuts off the air source. At this time, the lower surface of the diaphragm is completely in contact with the hyperbolic arc surface of the central gradually expanding sealing section 22, forming a full circle of equal width seal. There is no cavity residue on the inner side of the seal, achieving zero-leakage shutdown.

[0049] Opening adjustment: The actuator control module 8 receives external opening commands and performs closed-loop adjustment in conjunction with real-time displacement feedback to stabilize the valve stem at the target displacement position and maintain the corresponding deformation of the diaphragm, thereby achieving precise flow regulation.

[0050] Online cleaning: After the valve is closed, open the in-situ purge interface module 6 and introduce high-purity cleaning medium. The medium forms a spiral flow through the vortex guide groove, sweeping across the entire inner wall of the flow channel and the sealing surface, carrying away the residual medium and attached particles. After cleaning, close the purge interface and the valve can be directly put into the next cycle of operation without disassembly.

[0051] Example 2

[0052] This embodiment is a normally open, electrically operated, dead-zone-free diaphragm valve suitable for conveying special electronic gases. It has a nominal diameter of DN10, a rated working pressure of 1.2MPa, and is applicable to special electronic gases such as nitrogen trifluoride, tungsten hexafluoride, and hydrogen chloride. It is mainly used in the precision gas supply system of dry etching and chemical vapor deposition processes. It is equipped with an electric heating temperature control function to prevent easily liquefied gases from condensing and remaining.

[0053] The overall modular architecture of this embodiment is consistent with that of Embodiment 1, and also includes a valve body base module 1, an integrated flow channel lining module 2, a diaphragm sealing assembly module 3, a valve stem drive module 4, a position sensing feedback module 5, an in-situ purging interface module 6, a differential pressure balance channel module 7, and an actuator control module 8. The parameters and structure of each module have been specifically optimized for high-pressure gas conditions and temperature control requirements, as detailed below:

[0054] The valve body base module 1 is made of duplex stainless steel, and is precision machined after integral forging, with the pressure resistance rating increased to 2.0MPa. The inner cavity is machined with an annular heating chamber for installing heating components. The medium inlet port 9 and the medium outlet port 10 adopt a 1 / 4-inch VCR metal surface sealing structure, which is suitable for high-pressure gas transmission. The valve body is covered with an insulation layer to reduce heat loss.

[0055] The integrated flow channel lining module 2 is integrally milled from high-purity 316L stainless steel bar. The inner surface is electropolished and passivated, with a roughness Ra≤0.025μm and no micro-pits. The inner diameter of the inlet straight section 21 and the outlet straight section 23 are both 10mm. The top sealing arc radius of the central gradually expanding sealing section 22 is adjusted to 10mm, the sealing band width is 2.5mm, and the flow channel transition arc radius is R6mm, maintaining a continuous change of equal cross-sectional area throughout. A thermally conductive silicone grease layer is provided between the outer circular surface of the lining and the heating chamber of the valve body to ensure uniform heat transfer to the flow channel wall. The heating chamber is embedded with a thin-film polyimide heating element and a PT100 temperature sensor with a heating power of 20W, which can stably control the flow channel temperature within the set value ±0.5℃ range to prevent easily liquefied gases from condensing and remaining in the valve cavity.

[0056] In the diaphragm sealing assembly module 3, the reinforced polytetrafluoroethylene diaphragm layer 31 is made of modified PTFE material filled with carbon fiber, which improves the high-temperature creep resistance by 40% and has a thickness of 1.0 mm, making it suitable for higher differential pressure loads; the metal elastic support layer 32 is made of nickel-based alloy sheet, which has higher yield strength and can withstand greater deformation stress; the central connecting seat 33 adopts a spherical hinge structure, which contacts the valve stem end through a spherical surface, which can automatically compensate for slight valve stem misalignment, ensure uniform pressure on the sealing surface, and avoid insufficient local sealing pressure; the diaphragm edge adopts a double-layer pressure ring clamping structure, which further improves the sealing reliability under high pressure.

[0057] The valve stem drive module 4 adopts a servo electric drive structure, consisting of a micro servo motor, ball screw pair, guide mechanism and valve stem. The positioning accuracy is ±0.5μm. Compared with pneumatic drive, it has a more stable opening adjustment capability and a wider adjustment ratio, which can meet the precise control requirements of gas flow. The drive module has a built-in stroke limit and overload protection mechanism to prevent diaphragm damage due to overpressure.

[0058] The non-contact displacement sensor 51 of the position sensing feedback module 5 adopts a laser interferometric displacement sensor with a resolution of 0.1μm, which has higher detection accuracy and can capture the micron-level creep and thermal expansion of the diaphragm. In addition to the built-in displacement-opening calibration curve and creep compensation algorithm, the calibration storage unit 53 also adds a temperature-deformation compensation model. Combined with the temperature signal of the heating cavity, it compensates for the thermal expansion and contraction deformation of the diaphragm caused by temperature changes in real time, ensuring the dead zone control accuracy and sealing reliability over a wide temperature range.

[0059] The in-situ purging interface module 6 has two symmetrically distributed swirl guide groove groups 63 with a purging angle of 40°. The purging medium is high-purity nitrogen, which is used for pipeline replacement and particle purging before valve switching. The high-purity one-way valve unit 62 adopts a metal-to-metal sealing structure with a pressure rating consistent with the main valve to ensure no reverse leakage under high pressure.

[0060] The filter damping unit 71 of the differential pressure balance channel module 7 uses a nickel-based alloy sintered filter element with a precision of 0.1μm, which is suitable for high-pressure gas conditions; the volume of the pressure buffer chamber 72 is adjusted to 0.15mL, and a throttling orifice plate is added to further suppress the impact of pressure pulsation on the diaphragm; due to the low density of the gas medium and the large pressure fluctuation, the differential pressure balance design can significantly reduce the power consumption and heat generation of the electric drive and improve the operational stability.

[0061] The actuator control module 8 integrates a temperature control loop and a gas flow control algorithm. In addition to position closed-loop control, it can also finely adjust the diaphragm opening based on feedback signals from the downstream mass flow meter to achieve high-precision flow control without dead zones. The control module also has multiple diagnostic functions such as heating fault alarm, purging abnormality detection, and diaphragm life warning. It supports SEMI standard communication protocol access to semiconductor plant systems.

[0062] In addition to having all the dead-zone-free effects of Example 1, this embodiment also features high-pressure gas adaptation, temperature control and anti-condensation, and ultra-high-precision flow regulation. It is particularly suitable for the precise delivery of special gases in advanced etching and deposition processes, effectively avoiding gas condensation residue and particle generation, and significantly improving process stability and wafer yield.

[0063] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dead-zone-free diaphragm valve for high-purity semiconductor media, characterized in that, It includes a valve body base module (1), an integrated flow channel lining module (2), a diaphragm sealing assembly module (3), a valve stem drive module (4), and a position sensing feedback module (5). The integrated flow channel lining module (2) is embedded and fixed in the internal cavity of the valve body base module (1), forming a medium flow channel with a smooth transition throughout the entire process. There are no right-angle steps or abrupt changes in cross-section on the inner wall of the flow channel. The diaphragm sealing assembly module (3) is located at the top sealing port of the integrated flow channel liner module (2). The lower surface contour of the diaphragm is fully adapted to the top sealing surface contour of the integrated flow channel liner module (2). In the closed state, the inner side of the sealing contact surface is tangentially connected to the inner wall of the flow channel, with no cavities remaining. The output end of the valve stem drive module (4) is connected to the central area of ​​the diaphragm sealing assembly module (3) for driving the diaphragm to generate elastic deformation in order to realize valve opening and closing and opening degree adjustment; The position sensing feedback module (5) is installed on the side of the valve stem drive module (4) and is used to collect the valve stem displacement in real time and provide feedback on the actual deformation state of the diaphragm.

2. The dead-zone-free diaphragm valve for high-purity semiconductor media according to claim 1, characterized in that, It also includes an in-situ purging interface module (6), which is located on the inlet side of the valve body base module (1). Its outlet end is tangentially connected to the flow channel sidewall of the integrated flow channel lining module (2). The purging medium enters along the tangential direction of the inner wall of the flow channel and forms a spiral flow field that sweeps across the entire inner wall of the flow channel and the sealing surface.

3. The dead-zone-free diaphragm valve for high-purity semiconductor media according to claim 1, characterized in that, It also includes a differential pressure balance channel module (7), which is located in the inner wall of the valve body base module (1). One end of the module is connected to the drive cavity above the diaphragm sealing assembly module (3), and the other end is connected to the inlet side flow channel of the integrated flow channel lining module (2) to balance the static pressure difference between the upper and lower sides of the diaphragm.

4. The dead-zone-free diaphragm valve for high-purity semiconductor media according to claim 1, characterized in that, The integrated flow channel lining module (2) includes, in sequence, an inlet straight section (21), a central gradually expanding sealing section (22) and an outlet straight section (23) along the medium flow direction. The two adjacent sections are smoothly transitioned by a large-radius circular arc surface, and the overall cross-section of the flow channel maintains a continuous change in area along the flow direction.

5. The dead-zone-free diaphragm valve for high-purity semiconductor media according to claim 4, characterized in that, The top sealing edge of the central gradually expanding sealing section (22) adopts a hyperbolic arc surface structure, and the arc surface generatrix is ​​smoothly transitioned in both the axial and radial directions of the flow channel. When the diaphragm is closed, the diaphragm sealing component module (3) forms a full circle of equal width contact seal with the hyperbolic arc surface, and the inner edge of the sealing surface is connected to the tangent of the inner wall of the flow channel without any depressions or steps.

6. The dead-zone-free diaphragm valve for high-purity semiconductor media according to claim 5, characterized in that, The diaphragm sealing assembly module (3) consists of a reinforced polytetrafluoroethylene diaphragm layer (31), a metal elastic support layer (32), and a central connecting seat (33) from bottom to top. The three layers are combined by hot pressing and riveting to the center to form an integral structure. The outer edge of the diaphragm assembly is pressed and fixed to the top positioning step of the integrated flow channel lining module (2) by an annular pressure ring.

7. The dead-zone-free diaphragm valve for high-purity semiconductor media according to claim 6, characterized in that, The position sensing feedback module (5) includes a non-contact displacement sensor (51), a signal conditioning unit (52), and a calibration storage unit (53). The non-contact displacement sensor (51) is arranged opposite to the magnet assembly that is dynamically set on the valve stem drive module (4), and the displacement detection resolution is not less than 1 micrometer. The calibration storage unit (53) has a built-in displacement-opening calibration curve and diaphragm creep compensation algorithm, which are used to correct the opening reference in real time.

8. The dead-zone-free diaphragm valve for high-purity semiconductor media according to claim 2, characterized in that, The in-situ purging interface module (6) includes, in sequence along the medium flow direction, a purging inlet connector (61), a high-purity one-way valve unit (62), and a swirl guide channel group (63); the swirl guide channel group (63) includes 2-4 guide channels evenly distributed along the circumference of the flow channel, the outlet axis of the guide channel forms an angle of 30°-45° with the axial direction of the flow channel, and is arranged along the tangential direction of the inner wall of the flow channel.

9. The dead-zone-free diaphragm valve for high-purity semiconductor media according to claim 3, characterized in that, The differential pressure balance channel module (7) has a filter damping unit (71) and a pressure buffer chamber (72) arranged sequentially along the medium flow direction inside the channel; the filter damping unit (71) has a filtration accuracy less than the maximum allowable particle size in the medium; the pressure buffer chamber (72) is an expanded cavity used to attenuate inlet pressure fluctuations.

10. The dead-zone-free diaphragm valve for high-purity semiconductor media according to any one of claims 1 to 3, characterized in that, It also includes an actuator control module (8), whose signal input end is electrically connected to the position sensing feedback module (5) and whose control output end is electrically connected to the valve stem drive module (4); the actuator control module (8) forms a closed-loop control based on the real-time displacement feedback signal, accurately adjusts the valve stem stroke, and has the functions of automatic compensation for diaphragm creep and early warning of abnormal opening.

Images