Backpressure valve for stabilizing liquid medicine output of semiconductor process and assembly method of backpressure valve

Abstract

The invention relates to a back pressure valve for stabilizing semiconductor process liquid medicine output and an assembling method of the back pressure valve. The back pressure valve comprises a valve seat, a diaphragm assembly and a pressure control assembly. The valve seat is provided with a liquid inlet, a liquid outlet and an inclined partition face, a center through hole is formed in the partition face, and the inner diameter of the center through hole is gradually increased in the fluid flowing direction. The diaphragm assembly comprises an upper diaphragm, a lower diaphragm and a diaphragm connecting rod connecting the upper diaphragm and the lower diaphragm, the diaphragm connecting rod penetrates through the center through hole, and the outer surface of the diaphragm connecting rod comprises an upper sealing section and a middle circulation section which are different in radial size. The pressure control assembly is arranged above the upper diaphragm and used for applying adjusting acting force to the upper diaphragm. The back pressure valve can effectively restrain fluid turbulence, enhance the stability of fluid flowing, quickly and stably respond to pressure changes, and ensure the stability of output pressure of a main pipeline, so that the strict requirement of the semiconductor technology for the liquid medicine output stability is met.

Description

Technical Field

[0001] The present application relates to the technical field of pressure valves, and in particular to a back-pressure valve for stabilizing the output of semiconductor process liquid and an assembly method thereof. Background Art

[0002] Advanced semiconductor manufacturing processes, such as chemical mechanical polishing (CMP) and high-aspect-ratio etching, present unprecedented challenges to process fluid supply systems. These systems demand not only high fluid purity but also extremely stable output pressure. Pressure fluctuations must typically be controlled within ±0.2% of the set value to ensure uniformity within the process window. Furthermore, to ensure rapid process switching, the pressure control system must be designed with a response time of less than 50ms.

[0003] To stabilize the output of semiconductor process chemicals, a backpressure valve is typically installed in the main line to maintain a stable output pressure at the liquid outlet. However, with the semiconductor industry's continuously increasing performance requirements, traditional backpressure valves have difficulty achieving a smooth transition in the cross-sectional area of ​​the fluid channel when opening. This often leads to fluid turbulence and a lack of guaranteed smooth flow. Furthermore, the response speed and stability of backpressure control are poor, making it difficult to meet the stringent output pressure stability requirements of semiconductor process chemicals.

[0004] Utility model patent number CN216951676U discloses a liquid back-pressure valve, which includes a valve body, a membrane core assembly, and an adjustment assembly. The valve body is formed with an installation cavity, a liquid inlet, a liquid outlet, and a fluid channel connecting the liquid inlet and the liquid outlet, and a valve port is provided in the fluid channel. The membrane core assembly includes a valve needle and a diaphragm. The valve needle has a connecting end and a sealing end that are relatively arranged. The connecting end of the valve needle is connected to the diaphragm, and the sealing end of the valve needle can be movably inserted at the valve port. The diaphragm is arranged between the installation cavity and the fluid channel. The adjustment assembly is installed in the installation cavity and connected to the diaphragm. The adjustment assembly is used to adjust the degree of deformation of the diaphragm to control the position of the valve needle to increase or decrease the flow area of ​​the fluid channel to adjust the magnitude of the fluid pressure. The valve body of the related technology of this patent is a traditional chamber structure, which is prone to cause fluid turbulence during the valve opening process, and thus cannot effectively ensure the smooth flow of the fluid. When the back pressure valve of this related technology is opened, the cross-sectional area of ​​the fluid channel changes sharply (the rate of change exceeds 20% / ms), which in turn causes turbulence (Reynolds number is as high as 3500 or more), which has an adverse effect on the smooth flow of the process liquid.

[0005] Utility model patent number CN211259719U discloses a back-pressure valve, which includes: a valve cover; a valve body, wherein the valve cover and the valve body are arranged axially in succession to form a chamber between the valve cover and the valve body, and a fluid inlet and a fluid outlet are respectively provided on the valve body; a diaphragm, wherein the diaphragm is arranged in the chamber; and a sealing member, which is sealed and accommodated in a groove provided on the side of the valve body facing the diaphragm; wherein the groove includes a bottom wall and a radial inner side wall, and a space is formed between the bottom wall, the radial inner side wall and the sealing member, and the back-pressure valve includes a guide channel so that the fluid flowing into the space can flow to the fluid outlet via the guide channel. Although the patented technology has improved the spatial layout of the diaphragm and the sealing member, there is still room for improvement in ensuring a smooth transition of the cross-sectional area of ​​the fluid channel. Therefore, it is still difficult to fully suppress fluid turbulence, which in turn affects the stability of the fluid flow.

[0006] Invention Patent Publication No. 103671986A discloses a back-pressure valve comprising a valve seat, a valve core, a pneumatic diaphragm, a pneumatic upper cover, and an adjusting cover. The valve seat inlet forms an inclined surface with the valve core, with the valve seat inlet being the inlet front inclined surface and / or the inlet rear inclined surface. The middle portion of the valve core is fixed to the pneumatic diaphragm, which is composed of one or two groups. The diaphragm divides the chamber formed by the valve seat and the pneumatic upper cover into two. The pressure regulating mechanism of the patent-related technology acts indirectly on the valve core. This indirect action mode results in a control response lag, with the response time typically exceeding 100ms, far from meeting the fast response requirement of less than 50ms required by semiconductor processes. Significant pressure overshoot or lag will occur in high-frequency pressure regulation situations, directly affecting process stability and repeatability. Summary of the Invention

[0007] The main purpose of this application is to provide a back pressure valve for stabilizing the output of semiconductor process liquid. The main improvement is that it is suitable for the high stability (pressure fluctuation is controlled within ±0.2% of the set value) and fast response speed (response time is less than 50ms) required for the output of semiconductor process liquid.

[0008] The second main purpose of this application is to provide an assembly method for a back pressure valve for stabilizing the output of semiconductor process liquid medicine, and the assembled back pressure valve can be suitable for the semiconductor process liquid medicine output system.

[0009] The main purpose of this application is achieved through the following technical solutions, which include proposing a back pressure valve for stabilizing the output of semiconductor process liquid, including: A valve seat having a top opening, a bottom opening, a liquid inlet, and a liquid outlet; the liquid inlet is located on a first side of the valve seat and is used to connect to the liquid outlet section of the main pipeline; the liquid outlet is located on a second side of the valve seat opposite to the first side and is used to connect to the circulation section of the main pipeline; an inclined dividing surface is provided inside the valve seat, the dividing surface dividing the interior of the valve seat into a liquid inlet chamber communicating with the liquid inlet and a liquid outlet chamber communicating with the liquid outlet; the dividing surface is provided with a central through hole, the inner diameter of the central through hole gradually increasing from top to bottom; The diaphragm assembly comprises an upper diaphragm, a lower diaphragm and a diaphragm connecting rod connecting the upper diaphragm and the lower diaphragm, the upper diaphragm sealing the top opening, the lower diaphragm sealing the bottom opening, and the diaphragm connecting rod passing through the central through hole; the diaphragm connecting rod has a dynamic sealing surface along the axial direction, the dynamic sealing surface comprises an upper sealing section and a middle flow section, the radial dimension of the upper sealing section is larger than the radial dimension of the middle flow section; the upper sealing section is used to squeeze and fit with the upper end of the central through hole to form a seal when the diaphragm connecting rod moves downward, so as to block the liquid inlet chamber and the liquid storage chamber; the middle flow section is used to cooperate with the inner wall of the central through hole whose inner diameter gradually increases from top to bottom when the diaphragm connecting rod moves upward, so as to form an annular fluid channel connecting the liquid inlet chamber and the liquid outlet chamber; A pressure control assembly is provided above the upper diaphragm and is used to apply a regulating force downward to adjust the rated opening pressure of the back-pressure valve; wherein, when the fluid pressure at the liquid inlet is greater than the rated opening pressure, the upper diaphragm is deformed upward to drive the diaphragm connecting rod to move upward, so that the back-pressure valve releases pressure, and when the fluid pressure at the liquid inlet is less than the rated opening pressure, the upper diaphragm is deformed downward to drive the diaphragm connecting rod to move downward, so that the back-pressure valve holds pressure, thereby maintaining the output pressure of the liquid outlet section of the main line stable.

[0010] The principle behind this basic structural example is to provide a valve seat with an inclined partition surface and a central through-hole, in conjunction with a diaphragm connecting rod with an upper sealing section and a middle flow section. As the diaphragm connecting rod moves up and down, the middle flow section engages with the inner wall of the central through-hole, which has a gradually changing inner diameter, to form an annular fluid passage with a smooth, continuously changing cross-sectional area. Specific benefits include: (1) Minimize the streamline deformation of the process liquid when it flows through the back pressure valve, effectively reduce the local flow velocity gradient and shear stress, thereby significantly suppressing the generation of fluid turbulence and ensuring the smooth flow of the fluid; (2) It effectively avoids the rapid change of the flow channel cross-sectional area during the opening process of the traditional valve, thereby significantly improving the dynamic response performance of the back pressure valve, enabling the back pressure valve to respond sensitively and stably to pressure changes (response speed is less than 50ms), and ultimately achieve stable maintenance of the main line output pressure, meeting the high requirements of the semiconductor process for the stability of the liquid output.

[0011] In a preferred embodiment of the present application, the inclination angle of the partition surface is set between 30° and 60°, while the inner wall cross-section of the central through hole exhibits a tapered angle of 5° to 20° from top to bottom. A transition section is provided between the upper sealing section and the middle flow section of the diaphragm connecting rod. The inner diameter of the transition section varies to match the inner diameter of the central through hole, and the length of the transition section is 0.5 to 2 times the diameter of the middle flow section.

[0012] The adoption of the above-mentioned preferred structural features, especially limiting the inclination angle of the dividing surface to 30° to 60°, can effectively guide the liquid medicine to flow smoothly toward the central through hole, significantly reducing the flow dead zone and turbulence. The taper of the central through hole is limited to 5° to 20°, and the pressure drop and turbulence of the liquid medicine passing through are further suppressed by the gentle change of the inner wall cross section. At the same time, a transition section that matches the change in the inner diameter of the central through hole is added to the diaphragm connecting rod to achieve a smooth gradual change in diameter between the upper sealing section and the middle flow section. The optimized combination of these three specific parameters further enhances the smoothness and continuity of the cross-sectional area change of the annular fluid channel, avoids sudden changes in the flow state of the liquid medicine to the greatest extent, and thus more effectively improves the stability of the fluid flow.

[0013] In a preferred example, the present application can be further configured as follows: a support assembly is provided between the diaphragm assembly and the pressure control assembly, and the support assembly includes a support block, a first spring, an inner sealing ring of the support block and an outer sealing ring of the support block; an axial through hole is provided inside the support block, and the inner wall of the axial through hole is stepped to form an annular support surface for supporting the lower surface of the first spring, an inner circumferential surface of the support block is provided with an inner circumferential surface groove for accommodating the inner sealing ring of the support block, and an outer circumferential surface of the support block is provided with an outer circumferential surface groove for accommodating the outer sealing ring of the support block.

[0014] By adopting the preferred technical features of the above structure, a support assembly comprising a support block, a first spring, and inner and outer sealing rings is added to provide a stable and reliable support and sealing structure between the upper diaphragm and the pressure control assembly. This support assembly not only ensures stable load bearing for the first spring, but also, through the inner and outer sealing rings, ensures dynamic sealing between the movable and fixed components, thereby improving the airtightness and durability of the entire valve structure and ensuring that the force applied by the pressure control assembly is accurately and leak-free transmitted to the diaphragm assembly, thereby enhancing the accuracy and reliability of backpressure regulation.

[0015] In a preferred example, the present application can be further configured as follows: the upper diaphragm includes an upper diaphragm membrane body and an upper diaphragm connecting part, the upper diaphragm membrane body seals the top opening of the valve seat, and the upper diaphragm connecting part passes through the axial through hole inside the support block; wherein, the upper diaphragm connecting part is a hollow cylinder, and the outer surface and inner surface of the upper diaphragm connecting part are both provided with threads, the threads on the outer surface of the upper diaphragm connecting part are used to connect with the pressure control component, and the threads on the inner surface of the upper diaphragm connecting part are used to connect with the diaphragm connecting rod.

[0016] By adopting the preferred technical features of the above structure, the upper diaphragm connection is designed as a hollow cylinder with internal and external threads, providing a reliable and easy-to-assemble connection method. The external threads are used to connect to the pressure control assembly, while the internal threads are used to connect to the diaphragm connecting rod. This design ensures that the pressure control assembly, upper diaphragm, and diaphragm connecting rod are firmly fixed as a whole, ensuring the effective transmission of regulating force. At the same time, the modular connection method also simplifies the assembly and subsequent maintenance and disassembly of the valve, improving production efficiency and maintainability.

[0017] In a preferred example, the present application can be further configured as follows: the pressure control component is a pilot pressure control component, and the pilot pressure control component includes a pilot upper cover and a pilot floating pressure ring; the pilot upper cover is arranged on the top opening of the valve seat, and an air source channel is provided on the pilot upper cover; the pilot floating pressure ring is arranged inside the pilot upper cover, and is an annular cylindrical structure, wherein the axial main body of the pilot floating pressure ring is coaxially passed through the center of the first spring, and the upper end outer periphery of the pilot floating pressure ring is integrally formed with a radial extension portion, the upper surface of the first spring contacts and supports the radial extension portion, and the lower end inner periphery of the pilot floating pressure ring is provided with a thread so as to be connected to the upper diaphragm connection portion; wherein, the air source channel is used to introduce a pilot air source, and the pilot air source inflates the interior of the pilot upper cover through the air source channel to apply pressure to the pilot floating pressure ring, and transmits the pressure to the upper diaphragm through the pilot floating pressure ring.

[0018] By adopting the preferred technical features of the above-mentioned structure, the pressure control assembly is specifically designed as a pilot pressure control assembly. Pilot air is introduced through an external air supply channel, applying precise air pressure to the pilot floating pressure ring, which in turn transmits this pressure to the upper diaphragm. This approach enables precise, rapid, and remote automated adjustment of the backpressure valve's rated opening pressure, offering responsiveness and high control accuracy. It is particularly well-suited for automated semiconductor production lines requiring precise, programmed control, meeting the stringent process requirements for dynamic and accurate pressure control.

[0019] In a preferred example, the present application can be further configured as follows: the pressure control component is a manual pressure control component, and the manual pressure control component includes a manual upper cover, a manual floating pressure ring, a handwheel, a screw, a screw nut and a second spring; the manual upper cover is arranged on the top opening of the valve seat; the manual floating pressure ring is arranged in the manual upper cover, and is an annular cylindrical structure, wherein the axial main body of the manual floating pressure ring is coaxially passed through the center of the first spring, the upper cylinder of the manual floating pressure ring is used to accommodate the second spring, and the outer periphery of the upper end of the floating pressure ring is integrally formed with a radial extension portion, and the upper surface of the first spring The surface contacts and supports the radial extension part, and the inner circumference of the lower end of the floating pressure ring is provided with a thread so as to be connected to the upper diaphragm connection part; the handwheel is arranged on the top of the manual upper cover, and the handwheel is connected to the screw rod; the screw rod is matched with the screw rod nut inside the manual upper cover; the second spring is arranged in the upper cylinder and is connected to the screw rod and the screw rod nut; wherein, by adjusting the handwheel to drive the screw rod to move axially in the screw rod nut, the compression amount of the second spring is adjusted, thereby adjusting the adjustment force applied by the second spring to the floating pressure ring and transmitted to the upper diaphragm.

[0020] By adopting the preferred technical features of the above structure, the pressure control assembly is implemented as a manual pressure control assembly. By rotating the handwheel, the screw moves to adjust the pre-compression of the second spring, thereby accurately setting and calibrating the rated opening pressure of the back-pressure valve. This method provides a simple, reliable and durable reference pressure setting solution suitable for applications requiring on-site calibration or maintaining a fixed back-pressure value during specific process stages. It is intuitive to operate and does not require an external control unit.

[0021] In a preferred example, the present application may be further configured to further include a bottom plate, wherein the bottom plate is disposed below the bottom opening of the valve seat.

[0022] The optimized technical feature of the above structure, namely the addition of a base plate below the bottom opening of the valve seat, provides a stable mounting foundation for the back-pressure valve assembly. This base plate not only seals the bottom of the valve body and protects the lower diaphragm, but also connects to the valve seat and upper cover through its mounting holes, firmly assembling the entire valve into a single unit and enhancing the overall structural strength and sealing integrity of the valve.

[0023] The second main purpose of this application is achieved through the following technical solution, which proposes a method for assembling a back pressure valve for stabilizing the output of semiconductor process liquid, including the following steps: S1. Provide a valve seat, the valve seat having a top opening, a bottom opening, a liquid inlet, and a liquid outlet; the liquid inlet is located on a first side of the valve seat and is configured to connect to a liquid outlet section of a main pipeline; the liquid outlet is located on a second side of the valve seat, opposite to the first side, and is configured to connect to a circulation section of the main pipeline; an inclined partition surface is provided within the valve seat, the partition surface dividing the interior of the valve seat into a liquid inlet chamber communicating with the liquid inlet and a liquid outlet chamber communicating with the liquid outlet; the partition surface is provided with a central through hole, the inner wall cross-section of the central through hole having a tapered angle that gradually increases from top to bottom, such that the inner diameter of the central through hole gradually increases from top to bottom; S2. Assemble a support assembly, the support assembly comprising a support block, a first spring, an inner sealing ring of the support block, and an outer sealing ring of the support block; an axial through hole is provided inside the support block, and an inner wall of the axial through hole is stepped to form an annular support surface for supporting the lower surface of the first spring; the inner sealing ring of the support block is inserted into a groove on the inner circumferential surface of the support block, the outer sealing ring of the support block is inserted into a groove on the outer circumferential surface of the support block, and the first spring is arranged on the annular support surface; S3. Pass the floating pressure ring of the pressure control assembly through the first spring and the support block, and install an upper diaphragm on the bottom of the support block to connect the upper diaphragm to the floating pressure ring; S4. Install the support assembly, the floating pressure ring and the upper diaphragm into the valve seat, and connect the diaphragm connecting rod with the upper diaphragm, and also connect the lower diaphragm with the diaphragm connecting rod; the upper diaphragm is located at the top opening, the lower diaphragm is located at the bottom opening, and the diaphragm connecting rod passes through the central through hole; the diaphragm connecting rod has a dynamic sealing surface along the axial direction, and the dynamic sealing surface includes an upper sealing section and a middle flow section, and the radial dimension of the upper sealing section is larger than the radial dimension of the middle flow section; the upper sealing section is used to squeeze and fit with the upper end of the central through hole to form a seal when the diaphragm connecting rod moves downward, so as to block the liquid inlet chamber and the liquid storage chamber; the middle flow section is used to cooperate with the inner wall of the central through hole whose inner diameter gradually increases from top to bottom when the diaphragm connecting rod moves upward, so as to form an annular fluid channel connecting the liquid inlet chamber and the liquid outlet chamber; S5. Installing the regulating component of the pressure control assembly on the floating pressure ring, wherein the pressure control assembly applies a regulating force downward to adjust the rated opening pressure of the back-pressure valve; when the fluid pressure at the liquid inlet is greater than the rated opening pressure, the upper diaphragm deforms upward to drive the diaphragm connecting rod to move upward, thereby releasing pressure from the back-pressure valve; and when the fluid pressure at the liquid inlet is less than the rated opening pressure, the upper diaphragm deforms downward to drive the diaphragm connecting rod to move downward, thereby holding pressure in the back-pressure valve, thereby maintaining a stable output pressure at the liquid outlet section of the main line; S6. Install a bottom plate below the bottom opening of the valve seat.

[0024] This basic method example provides a logically clear and efficient back-pressure valve assembly method. Through steps S2 and S3, the support assembly, floating pressure ring, and upper diaphragm are pre-assembled into a modular component. Then, in step S4, the entire module is installed into the valve seat and connected to other components. This step-by-step, modular assembly process simplifies the operation, facilitates the installation quality and accuracy of key components (such as seals and springs), and effectively avoids incorrect or missing installation, thereby significantly improving assembly efficiency and the first-time pass rate of the final product, ensuring that the assembled back-pressure valve can achieve its expected stable performance. The specific effects are as follows: (1) Minimize the streamline deformation of the process liquid when it flows through the back pressure valve, effectively reduce the local flow velocity gradient and shear stress, thereby significantly suppressing the generation of fluid turbulence and ensuring the smooth flow of the fluid; (2) It effectively avoids the rapid change of the flow channel cross-sectional area during the opening process of the traditional valve, thereby significantly improving the dynamic response performance of the back pressure valve, enabling the back pressure valve to respond sensitively and stably to pressure changes (response speed is less than 50ms), and ultimately achieve stable maintenance of the main line output pressure, meeting the high requirements of the semiconductor process for the stability of the liquid output.

[0025] In a preferred example, the present application can be further configured as follows: in step S3, the floating pressure ring of the pressure control assembly is a pilot floating pressure ring; in step S5, the regulating component of the pressure control assembly includes a pilot upper cover; the pilot upper cover is arranged on the top opening of the valve seat, and an air source channel is provided on the pilot upper cover; the pilot floating pressure ring is located inside the pilot upper cover and is an annular cylindrical structure, wherein the axial main body of the pilot floating pressure ring is coaxially passed through the center of the first spring, the upper end outer periphery of the pilot floating pressure ring is integrally formed with a radial extension portion, the upper surface of the first spring contacts and supports the radial extension portion, and the lower end inner periphery of the pilot floating pressure ring is provided with a thread so as to be connected to the upper diaphragm connection portion; wherein, the air source channel is used to introduce a pilot air source, and the pilot air source inflates the interior of the pilot upper cover through the air source channel to apply pressure to the pilot floating pressure ring, and transmits the pressure to the upper diaphragm through the pilot floating pressure ring.

[0026] By utilizing the optimized technical features of the above method, detailed steps for assembling a pilot-operated back-pressure valve are defined. This method details how to precisely integrate key components, such as the pilot floating pressure ring and the pilot cover with air supply channels, into the valve, ensuring precise assembly of all components of the pilot pressure control assembly. This not only ensures smooth assembly but also ensures that the final product possesses the technical advantages of pilot control, including high precision, high response speed, and automated integration.

[0027] In a preferred example, the present application can be further configured as follows: in step S3, the floating pressure ring of the pressure control assembly is a manual floating pressure ring; in step S5, the adjusting component of the pressure control assembly includes a manual upper cover handwheel, a screw, a screw nut and a second spring; the manual upper cover is arranged on the top opening of the valve seat; the manual floating pressure ring is arranged in the manual upper cover, and is an annular cylindrical structure, wherein the axial main body of the manual floating pressure ring is coaxially penetrated through the center of the first spring, the upper cylinder of the manual floating pressure ring is used to accommodate the second spring, and the outer periphery of the upper end of the manual floating pressure ring is integrally formed with a radial extension portion, and the first The upper surface of the spring contacts and supports the radial extension portion, and the inner circumference of the lower end of the floating pressure ring is provided with a thread so as to be connected to the upper diaphragm connection portion; the handwheel is arranged on the top of the manual upper cover, and the handwheel is connected to the screw rod; the screw rod is matched with the screw rod nut inside the manual upper cover; the second spring is arranged in the upper cylinder and is connected to the screw rod and the screw rod nut; wherein, by adjusting the handwheel to drive the screw rod to move axially in the screw rod nut, the compression amount of the second spring is adjusted, thereby adjusting the adjustment force applied by the second spring to the manual floating pressure ring and transmitted to the upper diaphragm.

[0028] By utilizing the preferred technical features of the above method, detailed steps for assembling a manual back-pressure valve are defined. This method clarifies how to correctly assemble the components of the manual pressure control assembly, including the manual floating pressure ring, second spring, lead screw, handwheel, and manual cover. This assembly method ensures smooth and reliable mechanical transmission of the manual pressure control assembly, allowing the operator to precisely control the pressure of the second spring with the handwheel, thereby ensuring stable and reliable manual control of the back-pressure valve.

[0029] In summary, the technical solutions of the device or method of the present application examples include at least one of the following technical effects that contribute to the prior art: 1. By setting up a valve seat with an inclined partition surface and a central through hole inside, and using a diaphragm connecting rod with an upper sealing section and a middle flow section, the middle flow section of the diaphragm connecting rod will cooperate with the inner wall of the central through hole with a gradually changing inner diameter during the up and down movement of the diaphragm connecting rod, together forming an annular fluid channel with a smooth and continuously changing cross-sectional area. This structural design minimizes the streamline deformation of the process liquid when it flows through the back pressure valve, effectively reduces the local flow velocity gradient and shear stress, thereby significantly suppressing the generation of fluid turbulence and ensuring the smoothness of the fluid flow. At the same time, this structure avoids the sudden change in the cross-sectional area of ​​the flow channel when the traditional valve is opened. After testing, its response speed is less than 50ms, which fully meets the stringent requirements of the semiconductor process for pressure control, and ultimately achieves stable maintenance of the output pressure of the main line, meeting the high requirements of the semiconductor process for liquid output stability.

[0030] 2. The inclination angle of the dividing surface is limited to between 30° and 60°, which can effectively guide the liquid medicine to flow smoothly to the central through hole, significantly reduce the flow dead zone and reduce turbulence. The taper of the central through hole is controlled in the range of 5° to 20°, and its gentle change in the inner wall cross-section further reduces the pressure drop when the liquid medicine passes through and effectively suppresses turbulence. In addition, a transition section that matches the change in the inner diameter of the central through hole is added to the diaphragm connecting rod to ensure a smooth transition in diameter between the upper sealing section and the middle flow section. The optimized combination of these three specific parameters further enhances the smoothness and continuity of the cross-sectional area change of the annular fluid channel, avoids sudden changes in the flow state of the liquid medicine to the greatest extent, and thus more effectively improves the stability of the fluid flow.

[0031] 3. It provides a logically clear and efficient back-pressure valve assembly method. The support assembly, floating pressure ring, and upper diaphragm are preassembled into a modular component. This module is then installed into the valve seat and connected to the other components. This step-by-step, modular assembly process simplifies operation, ensures the installation quality and precision of key components (such as seals and springs), and effectively avoids incorrect or missing installation, thereby significantly improving assembly efficiency and the first-time pass rate of the final product, ensuring that the assembled back-pressure valve can achieve its expected stable performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A three-dimensional schematic diagram of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 1 of the present application is shown; Figure 2 A schematic diagram of the exploded components of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 1 of the present application is shown; Figure 3 A cross-sectional schematic diagram of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 1 of the present application is shown; Figure 4 A schematic diagram of an exploded view of the diaphragm assembly in Example 1 of the present application is shown; Figure 5 FIG1 is an exploded schematic diagram of the support assembly in Example 1 of the present application; Figure 6 FIG1 is an exploded schematic diagram of the pilot pressure control assembly in Example 1 of the present application; Figure 7 A three-dimensional schematic diagram of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 2 of the present application is shown; Figure 8 A schematic diagram of the exploded components of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 2 of the present application is shown; Figure 9 A cross-sectional schematic diagram of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 2 of the present application is shown; Figure 10 FIG2 is an exploded schematic diagram of the manual pressure control assembly in Example 2 of the present application; Figure 11 A schematic diagram illustrating the principle of a semiconductor process liquid delivery system in Example 3 of the present application is shown; Figure 12 A block diagram illustrating a method for assembling a back pressure valve for stabilizing the output of semiconductor process liquid according to Example 4 of the present application is provided; Figure 13 Draw the corresponding Figure 11 Schematic diagram of the assembly results of step S2 and step S3; Figure 14 Draw the corresponding Figure 11 Schematic diagram of the assembly result of step S4; Figure 15 A block diagram illustrating a method for assembling a back pressure valve for stabilizing the output of semiconductor process liquid in Example 5 of the present application is shown.

[0033] Explanation of reference numerals: 10, valve seat; 11, liquid inlet; 11a, liquid inlet bead; 11b, liquid inlet bead nut; 11c, liquid inlet limit buckle; 12, liquid outlet; 12a, liquid outlet bead; 12b, liquid outlet bead nut; 12c, liquid outlet limit buckle; 13, dividing surface; 14, liquid inlet chamber; 15, liquid outlet chamber; 16, central through hole; 17, valve seat mounting hole; 20, bottom plate; 21, bottom plate nut; 22, Bottom plate anti-corrosion plug; 23, bottom plate mounting hole; 31, upper diaphragm; 31a, upper diaphragm membrane body; 31b, upper diaphragm connecting portion; 32, lower diaphragm; 32a, lower diaphragm membrane body; 32b, lower diaphragm connecting portion; 33, diaphragm connecting rod; 33a, upper sealing section; 33b, middle flow section; 33c, transition section; 40, support block; 40a, axial through hole; 40b, annular support surface; 40c, inner peripheral surface groove; 40d, outer peripheral surface groove Groove; 41, inner sealing ring of support block; 42, outer sealing ring of support block; 43, first spring; 50, pilot pressure control assembly; 51, pilot cover; 51a, air source channel; 51b, pilot cover mounting hole; 52, pilot floating pressure ring; 53, pilot label; 61, cover fixing bolt; 62, cover fixing bolt spring washer; 63, cover fixing bolt flat washer; 64, cover anti-corrosion plug; 70, manual pressure control assembly; 71, manual cover ; 72. Screw; 72a. Screw nut; 73. Second spring; 74. Manual floating pressure ring; 75. Handwheel; 75a. Handwheel fixing bolt; 75b. Handwheel fixing bolt spring washer; 75c. Handwheel fixing bolt flat washer; 75d. Handwheel indicator disc label; 81. Process liquid storage tank; 82. Main line; 82a. Liquid outlet section; 82b. Circulation section; 82c. Liquid outlet branch pipe; 83. Drive pump; 84. Back pressure valve; 85. Isolation valve. DETAILED DESCRIPTION

[0034] The embodiments of the present application are combined with the accompanying drawings to clearly and completely illustrate the technical solutions. Please note that the embodiments shown are only part of the understanding of the concept of the present application, do not represent all, and are not the only explanation. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field on the premise of understanding the application concept of this application are within the scope of protection of this application.

[0035] For ease of understanding, the "pressure holding" mentioned in this specification refers to the process of increasing the upstream fluid pressure by closing the valve or reducing the opening; "pressure relief" refers to the process of reducing the upstream fluid pressure by opening the valve or increasing the opening. "Annular fluid channel" specifically refers to the fluid circulation space with an annular cross-section formed between the outer wall of the diaphragm connecting rod and the inner wall of the central through hole. It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of this application, the directional indication is only used to explain the relative position relationship, movement status, etc. between the various components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly. In order to more clearly explain the technical solution of this application, the back pressure valve will be described and explained in detail below, but it should be noted that the following content does not constitute a limitation on the scope of protection of this application.

[0036] The embodiments of the present application disclose a back-pressure valve for stabilizing the output of semiconductor process liquid. This back-pressure valve is a pressure-maintaining valve. Its operating mechanism is that when the pressure in the upstream pipeline rises, the valve opening will increase accordingly, thereby achieving pressure relief and ensuring that the upstream pressure remains stable. Specifically, when the pressure generated by the driving pump or other factors in the system cause the pressure in the outlet section (upstream) of the main line to be higher than the set value of the back-pressure valve, this pressure will act on the diaphragm inside the valve, and the upward force generated will overcome the downward regulating force of the back-pressure valve. As the upstream pressure increases, the degree to which the diaphragm is lifted gradually increases, driving the diaphragm connecting rod to move upward, thereby increasing the valve opening. This allows more fluid to flow back from the main line through the valve to the storage tank, thereby quickly releasing excess upstream pressure. This "pressure relief" working mode ensures that the back-pressure valve can maintain the pressure upstream (i.e., the point of use) constant at the set value.

[0037] In contrast, a traditional pressure-reducing valve or pressure-stabilizing valve is a downstream pressure control valve. Its operating principle is that when upstream pipeline pressure increases, the valve opening decreases, reducing fluid flow to maintain stable downstream pressure. The main purpose of a pressure-reducing valve is to reduce higher upstream pressure and stabilize it at a lower downstream pressure. It typically senses downstream pressure and adjusts the valve opening accordingly. When upstream pressure rises, the fluid flow rate and flow through the valve increase accordingly, which may cause downstream pressure to rise. To offset this effect, the internal mechanism of the pressure-reducing valve tightens, reducing the valve opening, thereby restricting fluid flow and maintaining stable downstream pressure. The main function of a pressure-reducing valve is to maintain a constant downstream pressure.

[0038] In summary, a back-pressure valve actively releases pressure to maintain stable upstream pressure, and its opening is positively correlated with upstream pressure. It is typically installed between the upstream and downstream pipes of the main pipeline circulation path. A pressure-stabilizing valve, on the other hand, actively throttles flow to maintain stable downstream pressure, and its opening is negatively correlated with upstream pressure. It is typically installed in the outlet branch connected to the upstream pipe. The back-pressure valve in this application utilizes its unique "the greater the pressure, the greater the opening" pressure-relieving mechanism to effectively address the pressure pulsation problem commonly found in semiconductor process liquid chemical systems, ensuring stable and clean liquid output at the point of use.

[0039] Furthermore, the control requirements for backpressure valves vary across different semiconductor production scenarios. Fully automated production lines tend to utilize remote pneumatic (pilot) control technology to achieve rapid and programmable pressure adjustment. However, in certain R&D and pilot production lines, or in specialized process equipment with strict cost control requirements, a backpressure valve that can accurately and stably manually set a backpressure baseline value and ensure long-term reliable operation after setting also has significant industrial value and application needs.

[0040] Example 1, Figure 1 A three-dimensional schematic diagram of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 1 of the present application is shown. Figure 2 A schematic diagram of the exploded components of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 1 of the present application is shown. Figure 3 A cross-sectional schematic diagram of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 1 of the present application is shown. Figure 4 A schematic diagram of the exploded view of the diaphragm assembly in Example 1 of the present application is shown. Figure 5 A schematic diagram of the exploded view of the support assembly in Example 1 of the present application is shown. Figure 6 A schematic diagram of an exploded view of the pilot pressure control assembly in Example 1 of the present application is shown.

[0041] Reference Figure 1 、 Figure 2 as well as Figure 3 A back pressure valve for stabilizing the output of semiconductor process liquid disclosed in Example 1 of the present application includes: a valve seat 10, a base plate 20 disposed below the valve seat 10, a diaphragm assembly disposed within the valve seat 10, a pilot pressure control assembly 50 disposed on the valve seat 10 and connected to the diaphragm assembly, and a support assembly disposed between the diaphragm assembly and the pilot pressure control assembly. The diaphragm assembly comprises an upper diaphragm 31, a lower diaphragm 32, and a diaphragm connecting rod 33 connecting the two. The support assembly includes a support block 40, a support block inner sealing ring 41, a support block outer sealing ring 42, and a first spring 43. The pilot pressure control assembly 50 includes a pilot upper cover 51 and a pilot floating pressure ring 52.

[0042] Refer again Figure 1 、 Figure 2 as well as Figure 3 , the valve seat 10 has a top opening, a bottom opening, a liquid inlet 11 and a liquid outlet 12. The liquid inlet 11 is located on the first side of the valve seat 10, and is used to connect to the liquid outlet section 82a of the main line 82. The liquid outlet 12 is located on the second side of the valve seat 10 opposite to the first side, and is used to connect to the circulation section 82b of the main line. The liquid inlet 11 is provided with an inlet bead 11a, an inlet bead nut 11b and an inlet limit buckle 11c. The main function of the inlet bead 11a is to assist in positioning and sealing. When connecting to the main line, it can initially cooperate with or buffer the main line, thereby facilitating positioning and connection. The inlet bead nut 11b generates an axial pressing force by cooperating with the thread of the liquid inlet 11. The pressing force acts on the inlet bead 11a, so that it is tightly pressed against the main line to ensure a reliable connection seal. The function of the liquid inlet limiting buckle 11c is to limit the axial movement of the liquid inlet bead nut 11b, thereby indirectly limiting the axial movement of the liquid inlet bead 11a. The liquid outlet 12 is provided with a liquid outlet bead 12a, a liquid outlet bead nut 12b, and a liquid outlet limiting buckle 12c. The functions of the liquid outlet bead 12a, the liquid outlet bead nut 12b, and the liquid outlet limiting buckle 12c at the liquid outlet 12 are similar to those of the liquid inlet bead 11a, the liquid inlet bead nut 11b, and the liquid inlet limiting buckle 11c at the liquid inlet 11, and will not be repeated here.

[0043] An inclined partition surface 13 is provided inside the valve seat 10. The partition surface 13 divides the interior of the valve seat 10 into a liquid inlet chamber 14 connected to the liquid inlet 11 and a liquid outlet chamber 15 connected to the liquid outlet 12. The partition surface 13 is provided with a central through hole 16 connecting the liquid inlet chamber 14 and the liquid outlet chamber 15. The inclination angle of the partition surface 13 is preferably in the range of 30° to 60°. This design can ensure that the liquid medicine flows smoothly to the central through hole 16, effectively reducing the flow dead zone and turbulence, and laying a solid foundation for the high stability of the laminar state. The inner wall cross-section of the central through hole 16 has a tapered change from top to bottom, so that the inner diameter of the central through hole 16 gradually increases from top to bottom, wherein the taper of the inner wall cross-section of the central through hole 16 is 5° to 20°. The relatively gentle taper design can effectively suppress the pressure drop and turbulence of the process liquid when passing through the central through hole 16, thereby further improving the smoothness of the liquid medicine flow. For example, computational fluid dynamics (CFD) simulations have shown that when the inclination angle of the partition surface 13 is 40° and the taper of the inner wall section of the central through hole 16 is 10°, the turbulence suppression rate is increased by 15% and the pressure drop is reduced by 20%.

[0044] Coordinate Reference Figure 1 、 Figure 2、 Figure 3 and Figure 4 The diaphragm assembly includes an upper diaphragm 31, a lower diaphragm 32, and a diaphragm connecting rod 33 connecting the upper and lower diaphragms 31 and 32. The upper diaphragm 31 seals the top opening of the valve seat 10, the lower diaphragm 32 seals the bottom opening of the valve seat 10, and the diaphragm connecting rod 33 passes through the central through-hole. The diaphragm connecting rod 33 has an axially oriented dynamic sealing surface comprising an upper sealing section 33a, a middle flow section 33b, and a transition section 33c located between the upper sealing section 33a and the middle flow section 33b.

[0045] When the diaphragm connecting rod 33 moves downward, the upper sealing section 33a tightly contacts the upper edge of the central through hole 16, effectively isolating the liquid inlet chamber 14 from the liquid outlet chamber 15. The radial dimension of the upper sealing section 33a is slightly larger than the minimum inner diameter D1 at the upper end of the central through hole 16 to ensure an effective seal. For example, the radial dimension of the upper sealing section can range from D1 + 0.05 mm to D1 + 0.2 mm (taking into account material deformation and sealing requirements).

[0046] As the diaphragm connecting rod 33 moves upward, the central flow section 33b cooperates with the gradually expanding inner wall of the central through hole 16 to form an annular fluid channel, connecting the liquid inlet chamber 14 with the liquid outlet chamber 15. The radial dimension of the central flow section 33b is smaller than that of the upper sealing section 33a and significantly smaller than the inner diameter D2 of the central through hole 16 at the pressure relief position, thereby forming a sufficient annular flow channel area. For example, the radial dimension of the central flow section is set within the range of D2-0.5mm to D2-2mm, ensuring sufficient flow capacity. At the same time, by precisely controlling the cross-sectional area of ​​the annular fluid channel, effective regulation of the pressure relief flow rate and stability is achieved.

[0047] The transition section 33c is used to achieve a smooth and gradual change in the inner diameter between the upper sealing section 33a and the middle flow section 33b. The change in the inner diameter of the transition section 33c matches the change in the inner diameter of the central through hole, thereby achieving a smooth and gradual change in the cross-sectional area of ​​the annular fluid passage. For example, the length of the transition section 33c is designed to be 0.5 to 2 times the diameter of the middle flow section. This design effectively prevents the process liquid from rapidly expanding or contracting between the upper sealing section 33a and the middle flow section 33b, thereby improving the stability of the process liquid flow.

[0048] By coordinating the internal structure of the valve seat 10 with the structure of the diaphragm connecting rod 33, the streamline deformation of the process liquid is minimized when passing through the back-pressure valve, avoiding sharp angles and sudden changes in cross-section. When the diaphragm connecting rod 33 moves, it cooperates with the inner wall of the central through hole 16, so that the cross-sectional area of ​​the formed annular fluid channel can change smoothly and continuously. This smooth change helps to reduce local flow velocity gradients and shear stress, thereby reducing the occurrence of turbulence, and can also reduce energy loss, improve the fluid efficiency of the back-pressure valve, and improve dynamic responsiveness, avoiding fluid shock and pressure fluctuations, making the back-pressure valve more sensitive and stable to pressure changes during opening and closing. Prototype tests show that at a pressure of 10 bar, the response time is 45ms, the pressure fluctuation is ±0.18%, and the turbulence suppression rate is 90% (Reynolds number <1500).

[0049] The upper diaphragm 31 includes an upper diaphragm body 31a and an upper diaphragm connecting portion 31b. The upper diaphragm body 31a seals the top opening of the valve seat, while the upper diaphragm connecting portion 31b extends through the axial through-hole within the support block. The upper diaphragm connecting portion 31b is a hollow cylinder with threads on both its outer and inner surfaces. The threads on the outer surface of the upper diaphragm connecting portion 31b are used to connect to the pilot pressure control assembly, while the threads on the inner surface of the upper diaphragm connecting portion 31b are used to connect to the upper end of the diaphragm connecting rod 33.

[0050] The lower diaphragm 32 includes a lower diaphragm body 32a and a lower diaphragm connecting portion 32b. The lower diaphragm body 32a seals the top opening of the valve seat. The surface of the lower diaphragm connecting portion 32b is provided with threads for connecting to the lower end of the diaphragm connecting rod 33.

[0051] Coordinate Reference Figure 1 、 Figure 2 、 Figure 3 as well as Figure 5 The support assembly includes a support block 40, a support block inner seal ring 41, a support block outer seal ring 42, and a first spring 43. An axial through-hole 40a is defined within the support block 40. The upper diaphragm connection portion 31b is connected to the pilot pressure control assembly through the axial through-hole 40a of the support block 40. The inner wall of the axial through-hole 40a is stepped to form an annular support surface 40b for supporting the lower surface of the first spring 43. An inner circumferential groove 40c is defined on the inner circumferential surface of the support block 40 for accommodating the support block inner seal ring 41, and an outer circumferential groove 40d is defined on the outer circumferential surface of the support block 40 for accommodating the support block outer seal ring 42.

[0052] Coordinate Reference Figure 1 、 Figure 2 、 Figure 3 as well as Figure 6 The pilot pressure control assembly 50 includes a pilot cover 51 and a pilot floating pressure ring 52. The pilot cover 51 is disposed on the top opening of the valve seat 10 and is provided with an air source passage 51a. The pilot floating pressure ring 52 is disposed within the pilot cover 51 and has an annular cylindrical structure. The axial main body of the pilot floating pressure ring 52 is coaxially inserted through the center of the first spring 43. A radial extension is integrally formed on the outer periphery of the upper end of the pilot floating pressure ring 52. The upper surface of the first spring 43 contacts and supports the radial extension. The inner periphery of the lower end of the pilot floating pressure ring is threaded for connection with the upper diaphragm connection portion 31b. The air source passage 51a is used to introduce a pilot air source. This air source inflates the interior of the pilot upper cover 51 through the air source passage 51a, applying pressure to the pilot floating pressure ring 52 (for example, a pressure range of 0.5 to 1.0 MPa). The pressure is then transmitted to the upper diaphragm 31 via the pilot floating pressure ring 52. A pilot label 53 may also be affixed to the pilot pressure control assembly 50 to indicate the model and parameter information of the backpressure valve.

[0053] Refer again Figure 1 、 Figure 2 as well as Figure 3 , the base plate 20 is arranged below the bottom opening of the valve seat 10. The base plate 20 is provided with a base plate mounting hole 23, the valve seat 10 is provided with a valve seat mounting hole 17, and the pilot upper cover 51 is provided with a pilot upper cover mounting hole 51b. The base plate mounting hole 23, the valve seat mounting hole 17 and the pilot upper cover mounting hole 51b cooperate with each other. For example, they can be respectively arranged at the four corners of the base plate 20, the valve seat 10 and the pilot upper cover 51. During the installation process, the base plate nut 21 can be first installed to the base plate mounting hole 23, and the base plate anti-corrosion plug 22 can be installed in the base plate mounting hole 23. Then the valve seat 10 is installed on the base plate 20, and the pilot upper cover 51 is installed on the valve seat 10. On the pilot upper cover mounting hole 51b, first install the upper cover fixing bolt flat washer 63, followed by the upper cover fixing bolt spring washer 62, and finally the upper cover fixing bolt 61. The bolt passes through the pilot cover mounting hole 51b and the valve seat mounting hole 17, and is locked with the base plate nut 21 in the base plate mounting hole 23. Furthermore, a base plate anti-corrosion plug 64 is installed in the pilot cover mounting hole 51b. The base plate anti-corrosion plug 22 and the base plate anti-corrosion plug 64 are made of, for example, polytetrafluoroethylene (PTFE).

[0054] The back pressure valve for stabilizing the output of semiconductor process liquid provided in Example 1 of the present application has the following working principle: by providing a valve seat 10 with an inclined partition surface 13 and a central through hole 16, and using a diaphragm connecting rod 33 with an upper sealing section 33a and a middle flow section 33b, when the diaphragm connecting rod 33 moves up and down, the middle flow section 33b on it can cooperate with the inner wall of the central through hole 16 with a gradually changing inner diameter, forming an annular fluid channel with a smooth and continuously changing cross-sectional area. Through the structural design of the back pressure valve, the process liquid can minimize the streamline deformation when flowing through, effectively reducing the local flow velocity gradient and shear stress. This significantly suppresses the generation of fluid turbulence, ensures the smoothness of fluid flow, and thus maintains the stability of the pressure in the system. At the same time, this structure avoids the sudden change in the flow channel cross-sectional area when the traditional valve is opened. After testing, its response speed is less than 50ms, which fully meets the stringent requirements of the semiconductor process for pressure control, and ultimately achieves the stable maintenance of the output pressure of the main line 82, meeting the high requirements of the semiconductor process for liquid output stability.

[0055] Example 2, Figure 7 A three-dimensional schematic diagram of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 2 of the present application is shown. Figure 8 A schematic diagram of the exploded components of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 2 of the present application is shown. Figure 9 A cross-sectional schematic diagram of a back pressure valve for stabilizing the output of semiconductor process liquid in Example 2 of the present application is shown. Figure 10 A schematic diagram of an exploded view of the manual pressure control assembly in Example 2 of the present application is shown.

[0056] Reference Figure 7 、 Figure 8 、 Figure 9 as well as Figure 10 The difference between Example 2 and Example 1 is that a manual pressure control assembly 70 is used instead of the pilot pressure control assembly 50 as the pressure control assembly. The manual pressure control assembly 70 includes a manual upper cover 71, a screw 72, a screw nut 72a, a second spring 73, a manual floating pressure ring 74, and a handwheel 75.

[0057] The manual upper cover 71 is positioned over the top opening of the valve seat 10. The manual floating pressure ring 74 is disposed within the manual upper cover 71 and has an annular cylindrical structure. The axial main portion of the manual floating pressure ring 74 coaxially passes through the center of the first spring 43. The upper cylindrical portion of the manual floating pressure ring 74 accommodates the second spring. A radially extending portion is integrally formed on the outer periphery of the upper end of the manual floating pressure ring 74, which contacts and supports the upper surface of the first spring 43. The lower inner periphery of the manual floating pressure ring 74 is threaded for connection to the upper diaphragm connection portion 31b.

[0058] The handwheel 75 is arranged at the top of the manual upper cover 71. The handwheel 75 is connected to the screw rod 72 via a handwheel fixing bolt 75a. The handwheel fixing bolt 75a is also provided with a handwheel fixing bolt spring washer 75b and a handwheel fixing bolt flat washer 75c. A handwheel indicator disc label 75d can be affixed to the handwheel 75 to identify the relevant model and parameters. The screw rod 72 is connected to the screw nut 72a inside the manual upper cover 71. The second spring 73 is arranged in the upper cylinder of the manual floating pressure ring 74 and is connected to the screw rod 72 and the screw nut 72a. The handwheel 75 is adjusted to drive the screw rod 72 to move axially in the screw nut 72a, thereby adjusting the compression amount of the second spring 73, thereby adjusting the regulating force applied by the second spring 73 to the manual floating pressure ring and transmitted to the upper diaphragm 31.

[0059] The backpressure valve for stabilizing the output of semiconductor process liquids, provided in Example 2 of the present application, operates as follows: The core fluid control principle of Example 2 is consistent with that of Example 1, differing in how the rated opening pressure is set. This embodiment utilizes a manual pressure control assembly 70, in which the operator sets or adjusts the valve's baseline backpressure value by rotating a handwheel 75. Specifically, rotation of handwheel 75 drives the screw 72 to slide axially within the screw nut 72a, thereby precisely regulating the initial compression of the second spring 73. This compression determines the constant preload applied to the manual floating pressure ring 74, which serves as the rated opening pressure setpoint for the backpressure valve. During process operation, the valve automatically releases or holds pressure based on a comparison of the upstream fluid pressure with a preset value. Therefore, this manual assembly is not intended for dynamic process control, but rather for initial process parameter calibration and setting, or for use in operating conditions where frequent backpressure changes are not required. It provides a stable and reliable pressure setting solution that does not require an external air or power source.

[0060] Example 3: This embodiment of the application also discloses a semiconductor process liquid output system, including the back pressure valve of Example 1 or 2. Figure 11 A schematic diagram illustrating the principle of a semiconductor process liquid output system in Example 3 of the present application is shown.

[0061] Reference Figure 11, a semiconductor process liquid output system disclosed in Example 3 of the present application includes: a process liquid storage tank 81, a main line 82 connected to the process liquid storage tank 81, a drive pump 83 arranged on the main line 82, a back pressure valve 84 and an isolation valve 85, wherein the back pressure valve 84 is the back pressure valve for stabilizing the output of the semiconductor process liquid in Example 1 or Example 2. The main line 82 is divided into two parts: a liquid outlet section 82a and a circulation section 82b, wherein the liquid outlet section 82a is connected to the liquid inlet of the back pressure valve 84, and the circulation section 82b is connected to the liquid outlet of the back pressure valve 84. On the liquid outlet section 82a, an isolation valve 85 is first provided, followed by the installation position of the drive pump 83. The liquid outlet section 82a can be connected to a plurality of liquid outlet branches 82c, and each liquid outlet branch 82c is connected to the use point of the semiconductor process liquid. Among them, the back pressure valve 84 has the function of balancing pressure pulsation. When the pressure in the main line 82 rises, its opening will increase accordingly to ensure the stable output of the semiconductor process liquid at the use point.

[0062] The semiconductor process liquid output system provided in Example 3 of the present application has the following working principle: precise back pressure control is achieved through the back pressure valve in Example 1 or Example 2, ensuring a stable supply of process liquid at multiple usage points and effectively balancing the pressure pulsation in the system.

[0063] Example 4: This embodiment of the application also discloses a method for assembling a back pressure valve for stabilizing the output of semiconductor process liquid. Figure 12 A block diagram illustrating a method for assembling a back pressure valve for stabilizing the output of semiconductor process liquid in Example 4 of the present application is shown. Figure 13 Draw the corresponding Figure 12 Assembly diagram of step S2 and step S3. Figure 14 Draw the corresponding Figure 12 Assembly diagram of step S4.

[0064] Reference Figure 12Example 4 of the present application discloses a method for assembling a back pressure valve for stabilizing the output of a semiconductor process liquid, which is used to assemble the back pressure valve in Example 1 of the present application. The method includes steps S1 to S6. Steps S1 to S5 are key steps. Specifically, step S1 is to provide the valve seat 10; step S2 is to assemble the support assembly, which includes a support block 40, a first spring 43, a support block inner sealing ring 41 and a support block outer sealing ring 42; step S3 is to pass the pilot floating pressure ring 52 of the pilot pressure control assembly 50 through the first spring 43 and the support block 40, and install the upper diaphragm 31 at the bottom of the support block 40 to connect the upper diaphragm 31 with the pilot floating pressure ring 52; step S4 is to install the support assembly, the pilot floating pressure ring 52 and the upper diaphragm 31 into the valve seat 10, and connect the diaphragm connecting rod 33 with the upper diaphragm 31, and also connect the lower diaphragm 32 with the diaphragm connecting rod 33; step S5 is to install the adjusting component of the pilot pressure control assembly 50 on the pilot floating pressure ring 52; step S6 is to install the base plate 20 below the bottom opening of the valve seat 10.

[0065] The operation of step S1 can be combined with reference to Figure 1 、 Figure 2 as well as Figure 3 A valve seat 10 is provided. The valve seat 10 has a top opening, a bottom opening, a liquid inlet 11, and a liquid outlet 12. The liquid inlet 11 is located on a first side of the valve seat 10 and is used to connect to the liquid outlet section 82a of the main line 82. The liquid outlet 12 is located on a second side of the valve seat 10 opposite to the first side and is used to connect to the circulation section 82b of the main line.

[0066] The valve seat 10 is internally provided with an inclined partition surface 13, which divides the interior of the valve seat 10 into an inlet chamber 14 connected to the inlet port 11 and an outlet chamber 15 connected to the outlet port 12. A central through hole 16 is provided on the partition surface 13, connecting the inlet chamber 14 and the outlet chamber 15. The inclination angle of the partition surface 13 is set between 30° and 60°. This design effectively guides the process liquid in and out of the central through hole smoothly, significantly reducing stagnation and turbulence, especially for process liquids with high viscosity or containing particles. The inner wall cross-section of the central through hole 16 tapers from top to bottom, with the inner diameter gradually increasing. The taper ranges from 5° to 20°. This design helps reduce pressure drop and turbulence when the process liquid passes through the central through hole 16. By providing a relatively gentle curvature, the pressure drop and turbulence of the process liquid can be suppressed when passing through the central through hole 16, further improving the smoothness of the process liquid flow.

[0067] The operations of step S2 and step S3 can be combined with reference to Figure 13, assemble the support assembly, which includes a support block 40, a first spring 43, an inner seal ring 41 of the support block, and an outer seal ring 42 of the support block (also with reference to Figure 5 ). The support block 40 is internally designed with an axial through hole 40a, the inner wall of which is stepped, specifically used to support the annular support surface 40b on the lower surface of the first spring 43. It has a compact structure and clear functions. Among them, the inner sealing ring 41 of the support block is first installed into the inner peripheral surface groove 40c of the support block 40, and then the outer sealing ring 42 of the support block is installed into the outer peripheral surface groove 40d of the support block 40. Then, grease is evenly applied to the surfaces of the inner sealing ring 41 and the outer sealing ring 42 of the support block, and the first spring 43 is set on the annular support surface 40b. Then, the pilot floating pressure ring 52 is passed through the first spring 43 and the support block 40. Subsequently, the diaphragm 31 is installed on the bottom of the support block 40 to ensure that the upper diaphragm 31 is firmly connected to the pilot floating pressure ring 52.

[0068] The operation of step S4 can be combined with reference to Figure 14 Next, assemble the support assembly, pilot floating pressure ring 52, and upper diaphragm 31 into the valve seat 10, and then invert the entire assembly into the tooling so that the upper diaphragm 31 can be accurately pressed into the upper sealing groove of the valve seat 10. This will allow the upper diaphragm 31 to seal the top opening of the valve seat 10. The diaphragm connecting rod 33 is screwed together with the upper diaphragm 31 through threaded engagement, and the lower diaphragm 32 is also screwed together with the diaphragm connecting rod 33 through threaded engagement. Figure 1 、 Figure 2 、 Figure 3 and Figure 4 The diaphragm assembly includes an upper diaphragm 31, a lower diaphragm 32, and a diaphragm connecting rod 33 connecting the upper and lower diaphragms 31 and 32. The upper diaphragm 31 is located at the top opening of the valve seat 10, while the lower diaphragm 32 is located at the bottom opening of the valve seat 10. The diaphragm connecting rod 33 passes through the central through-hole. The diaphragm connecting rod 33 is equipped with a dynamic sealing surface along the axial direction. This surface consists of an upper sealing section 33a, a middle flow section 33b, and a transition section 33c connecting the upper and lower sealing sections.

[0069] When the diaphragm connecting rod 33 moves downward, the upper sealing section 33a tightly engages the upper end of the central through hole 16, forming a seal that effectively isolates the liquid inlet chamber 14 from the liquid outlet chamber 15. The radial dimension of the upper sealing section 33a is slightly larger than the minimum inner diameter D1 of the upper end of the central through hole 16 to ensure an effective seal. For example, the radial dimension of the upper sealing section can range from D1 + 0.05 mm to D1 + 0.2 mm (taking into account material deformation and sealing requirements).

[0070] As the diaphragm connecting rod 33 moves upward, the central flow section 33b engages the gradually expanding inner wall of the central through hole 16, forming an annular fluid channel connecting the liquid inlet chamber 14 and the liquid outlet chamber 15. The radial dimension of the central flow section 33b is smaller than that of the upper sealing section 33a and significantly smaller than the inner diameter D2 of the central through hole 16 at the pressure relief position, thereby creating a sufficient annular flow channel area. For example, the radial dimension of the central flow section can range from D2-0.5mm to D2-2mm, providing sufficient flow capacity. By controlling the cross-sectional area of ​​the annular fluid channel, the pressure relief flow rate and stability can be adjusted.

[0071] The transition section 33c ensures a smooth transition between the inner diameters of the upper sealing section 33a and the middle flow section 33b. Its inner diameter changes in concert with the central through-hole, thereby ensuring a smooth change in the cross-sectional area of ​​the annular fluid passage. For example, the length of the transition section 33c can be set to 0.5 to 2 times the diameter of the middle flow section. This prevents sudden expansion or contraction of the process liquid between the upper sealing section 33a and the middle flow section 33b, helping to improve the stability of the process liquid flow.

[0072] By coordinating the internal structure of the valve seat 10 with the structure of the diaphragm connecting rod 33, the streamline deformation of the process liquid is minimized when passing through the back pressure valve, avoiding sharp angles and sudden changes in cross-section. When the diaphragm connecting rod 33 moves, it cooperates with the inner wall of the central through hole 16 to ensure that the cross-sectional area of ​​the annular fluid channel changes smoothly and continuously. This smooth change helps to reduce the local flow velocity gradient and reduce shear stress, thereby reducing the occurrence of turbulence, and can also reduce energy loss, improve the fluid efficiency of the back pressure valve, and improve dynamic responsiveness, avoiding fluid shock and pressure fluctuations, making the back pressure valve more sensitive and stable to pressure changes during opening and closing.

[0073] The upper diaphragm 31 comprises an upper diaphragm body 31a and an upper diaphragm connection portion 31b. The upper diaphragm body 31a tightly seals the top opening of the valve seat, while the upper diaphragm connection portion 31b smoothly passes through the axial through-hole within the support block. The upper diaphragm connection portion 31b is a hollow cylinder with threads on both its outer and inner surfaces. The threads on the outer surface of the upper diaphragm connection portion 31b are used to connect to the pilot pressure control assembly, while the threads on the inner surface of the upper diaphragm connection portion 31b are used to connect to the upper end of the diaphragm connecting rod 33.

[0074] The lower diaphragm 32 includes a lower diaphragm body 32a and a lower diaphragm connecting portion 32b. The lower diaphragm body 32a seals the top opening of the valve seat. The surface of the lower diaphragm connecting portion 32b is provided with threads for connecting to the lower end of the diaphragm connecting rod 33.

[0075] The operations of step S5 and step S6 can be combined with reference to Figure 1 、 Figure 2 as well as Figure 3 The regulating component of the pilot pressure control assembly 50 is mounted on the pilot floating pressure ring 52 , and the bottom plate 20 is mounted below the bottom opening of the valve seat 10 . The regulating component of the pilot pressure control assembly 50 includes a pilot upper cover 51 .

[0076] The pilot upper cover 51 is disposed on the top opening of the valve seat 10 and is provided with an air source passage 51a. The pilot floating pressure ring 52 is disposed within the pilot upper cover 51 and has an annular cylindrical structure. The axial main body of the pilot floating pressure ring 52 is coaxially inserted through the center of the first spring 43. A radial extension is integrally formed on the outer periphery of the upper end of the pilot floating pressure ring 52. The upper surface of the first spring 43 contacts and supports the radial extension. The lower inner periphery of the pilot floating pressure ring is threaded for connection with the upper diaphragm connection portion 31b. The air source passage 51a is used to introduce a pilot air source. The pilot air source inflates the interior of the pilot upper cover 51 through the air source passage 51a, applying pressure to the pilot floating pressure ring 52, which in turn transmits the pressure to the upper diaphragm 31 via the pilot floating pressure ring 52.

[0077] The base plate 20 is provided with a base plate mounting hole 23, the valve seat 10 is provided with a valve seat mounting hole 17, and the pilot cover 51 is provided with a pilot cover mounting hole 51b. The base plate mounting holes 23, the valve seat mounting holes 17, and the pilot cover mounting holes 51b cooperate with each other and, for example, can be respectively provided at the four corners of the base plate 20, the valve seat 10, and the pilot cover 51. During installation, the base plate nuts 21 can be first installed into the base plate mounting holes 23, and the base plate anti-corrosion plugs 22 can be installed in the base plate mounting holes 23. Then, the valve seat 10 can be installed on the base plate 20, and the pilot cover 51 can be installed on the valve seat 10. A flat upper cover fixing bolt washer 63, a spring upper cover fixing bolt washer 62, and an upper cover fixing bolt 61 are sequentially installed in the pilot upper cover mounting hole 51b. The upper cover fixing bolt 61 passes through the pilot upper cover mounting hole 51b and the valve seat mounting hole 17, and is locked and secured with the base plate nut 21 in the base plate mounting hole 23. An upper cover anti-corrosion plug 64 is then installed in the pilot upper cover mounting hole 51b. After confirming that the backpressure valve is functioning properly and has no abnormalities, a pilot label 53 should be affixed to the top of the pilot upper cover 51. This label clearly indicates the model, pressure range, and other key parameters of the backpressure valve to ensure accurate identification and proper use by the operator. Then, install the liquid inlet bead 11a, liquid inlet bead nut 11b, and liquid inlet limit buckle 11c at the liquid inlet 11. Install the liquid outlet bead 12a, liquid outlet bead nut 12b, and liquid outlet limit buckle 12c at the liquid outlet 12.

[0078] The liquid inlet bead 11a is used to assist in positioning and sealing. When connected to the main pipeline, the liquid inlet bead 11a can form an initial fit or buffer with the main pipeline to help position the connection. The liquid inlet bead nut 11b cooperates with the thread on the liquid inlet 11 to generate an axial clamping force. The clamping force acts on the liquid inlet bead 11a so that the liquid inlet bead 11a is pressed together with the main pipeline to form a sealed and reliable connection. The liquid inlet limit buckle 11c is used to limit the axial movement range of the liquid inlet bead nut 11b, thereby limiting the axial movement range of the liquid inlet bead 11a. The liquid outlet 12 is provided with a liquid outlet bead 12a, a liquid outlet bead nut 12b and a liquid outlet limiting buckle 12c. The functions of the liquid outlet bead 12a, the liquid outlet bead nut 12b and the liquid outlet limiting buckle 12c at the liquid outlet 12 are similar to those of the liquid inlet bead 11a, the liquid inlet bead nut 11b and the liquid inlet limiting buckle 11c at the liquid inlet 11, and are not repeated here.

[0079] The assembly method for a back-pressure valve for stabilizing the output of semiconductor process liquids, provided in Example 4 of the present application, has the following operating principle: It provides a logically clear and efficient back-pressure valve assembly method. By pre-assembling the support assembly, pilot floating pressure ring 52, and upper diaphragm 31 into a modular component, then installing the entire module into the valve seat 10 and connecting other components, this step-by-step, modular assembly process simplifies operation, facilitates ensuring the installation quality and accuracy of key components (such as sealing rings and springs), effectively avoids mis-installation or missing installation, and thus significantly improves assembly efficiency and the first-time pass rate of the final product, ensuring that the assembled back-pressure valve can achieve its expected stable performance.

[0080] Example 5, Figure 15 A block diagram illustrating a method for assembling a back pressure valve for stabilizing the output of semiconductor process liquid in Example 5 of the present application is shown.

[0081] Reference Figure 15 Example 5 of the present application discloses an assembly method of a back pressure valve for stabilizing the output of semiconductor process liquid, which is used to assemble the back pressure valve in Example 2 of the present application. The method covers steps S10 to S60. Specifically, step S10 is to provide the valve seat 10; step S20 is to assemble the support assembly, which includes a support block 40, a first spring 43, a support block inner sealing ring 41 and a support block outer sealing ring 42; step S30 is to pass the manual floating pressure ring 74 of the manual pressure control assembly 70 through the first spring 43 and the support block 40, and install the upper diaphragm 31 at the bottom of the support block 40 to connect the upper diaphragm 31 with the manual floating pressure ring 74; step S40 is to install the support assembly, the manual floating pressure ring 74 and the upper diaphragm 31 into the valve seat 10, and connect the diaphragm connecting rod 33 with the upper diaphragm 31, and also connect the lower diaphragm 32 with the diaphragm connecting rod 33; step S50 is to install the adjusting component of the manual pressure control assembly 70 on the manual floating pressure ring 74; step S60 is to install the base plate 20 below the bottom opening of the valve seat 10.

[0082] The main difference between Example 5 and Example 4 is step S50. Figure 10 The adjustment components of the manual pressure control assembly 70 include a manual upper cover 71, a screw 72, a screw nut 72a, a second spring 73, a manual floating pressure ring 74, and a handwheel 75. After assembling the screw 72 and screw nut 72a, the assembly is installed into the manual upper cover 71. The handwheel 75 is then inserted into the screw 72 from the top of the manual upper cover 71. The handwheel fixing bolt washer 75c, the handwheel fixing bolt spring washer 75b, and the handwheel fixing bolt 75a are then installed in sequence to complete the locking.

[0083] The manual upper cover 71 is disposed on the top opening of the valve seat 10. The manual floating pressure ring 74 is disposed within the manual upper cover 71 and has an annular cylindrical structure. The axial main body of the manual floating pressure ring 74 coaxially passes through the center of the first spring 43. The upper cylindrical portion of the manual floating pressure ring 74 is used to accommodate the second spring. The upper outer periphery of the manual floating pressure ring 74 is integrally formed with a radial extension. The upper surface of the first spring 43 contacts and supports the radial extension. The lower inner periphery of the manual floating pressure ring 74 is threaded for connection to the upper diaphragm connection portion 31b.

[0084] The handwheel 75 is arranged at the top of the manual upper cover 71. The handwheel 75 is connected to the screw rod 72 via a handwheel fixing bolt 75a. A handwheel fixing bolt spring washer 75b and a handwheel fixing bolt flat washer 75c are also provided at the handwheel fixing bolt 75a. The screw rod 72 is connected to the screw nut 72a inside the manual upper cover 71. The second spring 73 is arranged in the upper cylinder of the manual floating pressure ring 74 and is connected to the screw rod 72 and the screw nut 72a. The handwheel 75 is adjusted to drive the screw rod 72 to move axially in the screw nut 72a, thereby adjusting the compression amount of the second spring 73, thereby adjusting the regulating force applied by the second spring 73 to the manual floating pressure ring and transmitted to the upper diaphragm 31.

[0085] The assembly method for a back-pressure valve for stabilizing the output of semiconductor process liquid chemicals, provided in Example 5 of the present application, has the following operating principle: it clarifies how to correctly assemble the components of a manual pressure control assembly 70, including a manual floating pressure ring 74, a second spring 73, a screw 72, a handwheel 75, and a manual upper cover 71. This assembly method ensures smooth and reliable mechanical transmission of the manual pressure control assembly 70, and enables the operator to precisely adjust the pressure of the second spring 73 using the handwheel 75, thereby achieving stable and reliable manual control of the back-pressure valve.

[0086] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A back pressure valve for stabilizing the output of semiconductor process liquid, characterized in that: include: A valve seat (10) having a top opening, a bottom opening, a liquid inlet (11) and a liquid outlet (12); the liquid inlet (11) is located on a first side of the valve seat (10) and is used to connect to a liquid outlet section (82a) of a main pipeline (82); the liquid outlet (12) is located on a second side of the valve seat (10) opposite to the first side and is used to connect to a circulation section (82b) of the main pipeline (82); an inclined partition surface (13) is provided inside the valve seat (10), and the partition surface (13) divides the inside of the valve seat (10) into a liquid inlet chamber (14) communicating with the liquid inlet (11) and a liquid outlet chamber (15) communicating with the liquid outlet (12); the partition surface (13) is provided with a central through hole (16), and the inner diameter of the central through hole (16) gradually increases from top to bottom; A diaphragm assembly comprises an upper diaphragm (31), a lower diaphragm (32) and a diaphragm connecting rod (33) connecting the upper diaphragm (31) and the lower diaphragm (32), wherein the upper diaphragm (31) seals the top opening, the lower diaphragm (32) seals the bottom opening, and the diaphragm connecting rod (33) passes through the central through hole (16); the diaphragm connecting rod (33) has a dynamic sealing surface along the axial direction, the dynamic sealing surface comprises an upper sealing section (33a) and a middle flow section (33b), and the radial dimension of the upper sealing section (33a) is greater than The radial dimension of the middle flow section (33b); the upper sealing section (33a) is used to squeeze and fit with the upper end of the central through hole (16) to form a seal when the diaphragm connecting rod (33) moves downward, so as to block the liquid inlet chamber (14) and the liquid outlet chamber (15); the middle flow section (33b) is used to fit with the inner wall of the central through hole (16) whose inner diameter gradually increases from top to bottom when the diaphragm connecting rod (33) moves upward, so as to form an annular fluid channel connecting the liquid inlet chamber (14) and the liquid outlet chamber (15); A pressure control assembly is provided above the upper diaphragm (31) and is used to apply a regulating force downward to regulate the rated opening pressure of the back pressure valve (84); wherein, when the fluid pressure of the liquid inlet (11) is greater than the rated opening pressure, the upper diaphragm (31) is deformed upward to drive the diaphragm connecting rod (33) to move upward, so that the back pressure valve (84) is relieved of pressure, and when the fluid pressure of the liquid inlet (11) is less than the rated opening pressure, the upper diaphragm (31) is deformed downward to drive the diaphragm connecting rod (33) to move downward, so that the back pressure valve (84) is held back, thereby maintaining the output pressure of the liquid outlet section (82a) of the main line (82) stable.

2. The back pressure valve according to claim 1, characterized in that: The inclination angle of the partition surface (13) is 30° to 60°; the inner wall cross section of the central through hole (16) has a tapered change from top to bottom, wherein the tapered angle of the inner wall cross section of the central through hole (16) is 5° to 20°; a transition section (33c) is provided between the upper sealing section (33a) and the middle flow section (33b) of the diaphragm connecting rod (33), and the inner diameter change of the transition section (33c) matches the inner diameter change of the central through hole (16), wherein the length of the transition section (33c) is 0.5 to 2 times the diameter of the middle flow section (33b).

3. The back pressure valve according to claim 1, characterized in that: It also includes a bottom plate (20), which is arranged below the bottom opening of the valve seat (10).

4. The back pressure valve according to any one of claims 1 to 3, characterized in that: A support assembly is provided between the diaphragm assembly and the pressure control assembly, and the support assembly includes a support block (40), a first spring (43), an inner sealing ring of the support block (41), and an outer sealing ring of the support block (42); an axial through hole (40a) is provided inside the support block (40), and the inner wall of the axial through hole (40a) is stepped to form an annular support surface (40b) for supporting the lower surface of the first spring (43); an inner peripheral surface groove (40c) for accommodating the inner sealing ring (41) of the support block is provided on the inner peripheral surface of the support block (40), and an outer peripheral surface groove (40d) for accommodating the outer sealing ring (42) of the support block is provided on the outer peripheral surface of the support block (40).

5. The back pressure valve according to claim 4, characterized in that: The upper diaphragm (31) includes an upper diaphragm membrane body (31a) and an upper diaphragm connecting portion (31b), wherein the upper diaphragm membrane body (31a) seals the top opening of the valve seat (10), and the upper diaphragm connecting portion (31b) passes through the axial through hole (40a) inside the support block (40); wherein the upper diaphragm connecting portion (31b) is a hollow cylinder, and both the outer surface and the inner surface of the upper diaphragm connecting portion (31b) are provided with threads, the threads on the outer surface of the upper diaphragm connecting portion (31b) are used to connect to the pressure control component, and the threads on the inner surface of the upper diaphragm connecting portion (31b) are used to connect to the diaphragm connecting rod (33).

6. The back pressure valve according to claim 5, characterized in that: The pressure control assembly is a pilot pressure control assembly (50), and the pilot pressure control assembly (50) includes a pilot upper cover (51) and a pilot floating pressure ring (52); the pilot upper cover (51) is arranged on the top opening of the valve seat (10), and the pilot upper cover (51) is provided with an air source channel (51a); the pilot floating pressure ring (52) is arranged inside the pilot upper cover (51) and has an annular cylindrical structure, wherein the axial main body of the pilot floating pressure ring (52) is coaxially penetrated through the center of the first spring (43), and the pilot floating pressure ring The outer periphery of the upper end of (52) is integrally formed with a radial extension portion, the upper surface of the first spring (43) contacts and supports the radial extension portion, and the inner periphery of the lower end of the pilot floating pressure ring (52) is provided with a thread so as to be connected to the upper diaphragm connecting portion (31b); wherein, the air source channel (51a) is used to introduce a pilot air source, and the pilot air source inflates the interior of the pilot upper cover (51) through the air source channel (51a) to apply pressure to the pilot floating pressure ring (52), and transmits the pressure to the upper diaphragm (31) through the pilot floating pressure ring (52).

7. The back pressure valve according to claim 5, characterized in that: The pressure control assembly is a manual pressure control assembly (70), and the manual pressure control assembly (70) includes a manual upper cover (71), a manual floating pressure ring (74), a hand wheel (75), a screw (72), a screw nut (72a) and a second spring (73); the manual upper cover (71) is arranged on the top opening of the valve seat (10); the manual floating pressure ring (74) is arranged in the manual upper cover (71), and has an annular cylindrical structure, wherein the axial main body of the manual floating pressure ring (74) is coaxially penetrated through the center of the first spring (43), the upper cylinder of the manual floating pressure ring (74) is used to accommodate the second spring (73), and the outer peripheral edge of the upper end of the manual floating pressure ring (74) is integrally formed with a radial extension portion, and the upper surface of the first spring (43) contacts and supports the radial extension portion. The inner circumference of the lower end of the manual floating pressure ring (74) is provided with a thread so as to be connected to the upper diaphragm connecting portion (31b); the handwheel (75) is arranged on the top of the manual upper cover (71), and the handwheel (75) is connected to the screw rod (72); the screw rod (72) is matched and connected with the screw nut (72a) inside the manual upper cover (71); the second spring (73) is arranged in the upper cylinder and is connected to the screw rod (72) and the screw nut (72a); wherein, by adjusting the handwheel (75) to drive the screw rod (72) to move axially in the screw nut (72a), the compression amount of the second spring (73) is adjusted, thereby adjusting the regulating force applied by the second spring (73) to the manual floating pressure ring (74) and transmitted to the upper diaphragm (31).

8. A method for assembling a back pressure valve for stabilizing the output of semiconductor process liquid, characterized in that: The following steps are involved: S1. Provide a valve seat (10), wherein the valve seat (10) has a top opening, a bottom opening, a liquid inlet (11), and a liquid outlet (12); the liquid inlet (11) is located on a first side of the valve seat (10) and is used to connect to a liquid outlet section (82a) of a main line (82); the liquid outlet (12) is located on a second side of the valve seat (10) opposite to the first side and is used to connect to a circulation section (82b) of the main line (82); the valve seat (10) ) is provided with an inclined dividing surface (13) inside, and the dividing surface (13) divides the inside of the valve seat (10) into a liquid inlet chamber (14) communicating with the liquid inlet (11) and a liquid outlet chamber (15) communicating with the liquid outlet (12); the dividing surface (13) is provided with a central through hole (16), and the inner wall cross section of the central through hole (16) has a tapered change that gradually increases from top to bottom, so that the inner diameter of the central through hole (16) gradually increases from top to bottom; S2. Assemble the support assembly, the support assembly comprising a support block (40), a first spring (43), an inner sealing ring of the support block (41), and an outer sealing ring of the support block (42), wherein an axial through hole (40a) is provided inside the support block (40), and the inner wall of the axial through hole (40a) is stepped to form an annular support surface (40b) for supporting the lower surface of the first spring (43), wherein the inner sealing ring (41) of the support block is inserted into the inner peripheral surface groove (40c) of the support block (40), and the outer sealing ring (42) of the support block is inserted into the outer peripheral surface groove (40d) of the support block (40), and the first spring (43) is arranged on the annular support surface (40b); S3, passing the floating pressure ring of the pressure control assembly through the first spring (43) and the support block (40), and installing an upper diaphragm (31) on the bottom of the support block (40) to connect the upper diaphragm (31) to the floating pressure ring; S4. Install the support assembly, the floating pressure ring and the upper diaphragm (31) into the valve seat (10), connect the diaphragm connecting rod (33) to the upper diaphragm (31), and connect the lower diaphragm (32) to the diaphragm connecting rod (33); the upper diaphragm (31) is located at the top opening, the lower diaphragm (32) is located at the bottom opening, and the diaphragm connecting rod (33) passes through the central through hole (16); the diaphragm connecting rod (33) has a dynamic sealing surface in the axial direction, and the dynamic sealing surface includes an upper sealing section (33a) and a middle flow section (33b), and the upper The radial dimension of the upper sealing section (33a) is greater than the radial dimension of the middle flow section (33b); the upper sealing section (33a) is used to squeeze and fit with the upper end of the central through hole (16) to form a seal when the diaphragm connecting rod (33) moves downward, so as to block the liquid inlet chamber (14) and the liquid outlet chamber (15); the middle flow section (33b) is used to fit with the inner wall of the central through hole (16) whose inner diameter gradually increases from top to bottom when the diaphragm connecting rod (33) moves upward, so as to form an annular fluid channel connecting the liquid inlet chamber (14) and the liquid outlet chamber (15); S5. Install the regulating component of the pressure control assembly on the floating pressure ring, wherein the pressure control assembly applies a regulating force downward to adjust the rated opening pressure of the back pressure valve; when the fluid pressure of the liquid inlet (11) is greater than the rated opening pressure, the upper diaphragm (31) is deformed upward to drive the diaphragm connecting rod (33) to move upward, so that the back pressure valve (84) releases pressure, and when the fluid pressure of the liquid inlet (11) is less than the rated opening pressure, the upper diaphragm (31) is deformed downward to drive the diaphragm connecting rod (33) to move downward, so that the back pressure valve (84) is held in pressure, thereby maintaining the output pressure of the liquid outlet section (82a) of the main line (82) stable; S6. Installing a bottom plate (20) below the bottom opening of the valve seat (10).

9. The assembly method according to claim 8, characterized in that: In step S3, the floating pressure ring of the pressure control component is a pilot floating pressure ring (52). In step S5, the regulating component of the pressure control component includes a pilot upper cover (51); the pilot upper cover (51) is arranged on the top opening of the valve seat (10), and the pilot upper cover (51) is provided with an air source channel (51a); the pilot floating pressure ring (52) is located inside the pilot upper cover (51) and is an annular cylindrical structure, wherein the axial main body of the pilot floating pressure ring (52) is coaxially penetrated through the center of the first spring (43), and the pilot floating pressure ring (52) is provided with a pilot upper cover (51a). The outer peripheral edge of the upper end of the dynamic pressure ring (52) is integrally formed with a radial extension portion, the upper surface of the first spring (43) contacts and supports the radial extension portion, and the inner peripheral surface of the lower end of the pilot floating pressure ring (52) is provided with a thread so as to be connected to the upper diaphragm connecting portion (31b); wherein, the air source channel (51a) is used to introduce a pilot air source, and the pilot air source inflates the interior of the pilot upper cover (51) through the air source channel (51a) to apply pressure to the pilot floating pressure ring (52), and transmits the pressure to the upper diaphragm (31) through the pilot floating pressure ring (52).

10. The assembly method according to claim 8, characterized in that: In step S3, the floating pressure ring of the pressure control assembly is a manual floating pressure ring (74), and in step S5, the regulating component of the pressure control assembly includes a manual upper cover (71), a hand wheel (75), a screw (72), a screw nut (72a) and a second spring (73); the manual upper cover (71) is arranged on the top opening of the valve seat (10); the manual floating pressure ring (74) is arranged in the manual upper cover (71) and has an annular cylindrical structure, wherein the axial main body of the manual floating pressure ring (74) is coaxially penetrated through the center of the first spring (43), the upper cylinder of the manual floating pressure ring (74) is used to accommodate the second spring (73), the outer peripheral edge of the upper end of the manual floating pressure ring (74) is integrally formed with a radial extension portion, the upper surface of the first spring (43) contacts and supports the radial extension portion, and the inner peripheral surface of the lower end of the manual floating pressure ring (74) is provided with a thread so as to be connected to the upper diaphragm connecting portion (31b); In step S5, the handwheel (75) is arranged on the top of the manual upper cover (71), and the handwheel (75) is connected to the screw rod (72); the screw rod (72) is connected to the screw rod nut (72a) inside the manual upper cover (71); the second spring (73) is arranged in the upper cylinder and is connected to the screw rod (72) and the screw rod nut (72a); wherein, by adjusting the handwheel (75) to drive the screw rod (72) to move axially in the screw rod nut (72a), the compression amount of the second spring (73) is adjusted, thereby adjusting the regulating force applied by the second spring (73) to the manual floating pressure ring (74) and transmitted to the upper diaphragm (31).

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