Air duct pressure control system

Abstract

The utility model provides an air duct pressure control system which comprises an air inlet, an air outlet, an operation air duct, a bypass air duct, a variable-frequency fan, a pressure meter, a first air door, a second air door, a third air door, a fourth air door and a controller. The controller can control the operation frequency of the variable-frequency fan, the first air door, the second air door and the third air door switch the air channel for air flowing, the fourth air door adjusts the pressure of the air channel, no fan needs to be additionally arranged in the bypass air channel, and in the operation, stopping and switching periods of the processing equipment and the variable-frequency fan, the air channel pressure can be adjusted. And the pressure value in the air duct can reach and be stably kept at the target pressure value.

Description

Technical Field

[0001] This application relates to a pressure control system, and particularly to an air duct pressure control system. Background Art

[0002] In semiconductor manufacturing processes, the control of the cleanliness and differential pressure of the gases in the equipment and environment is an important factor. Figure 1 The following is a block diagram of a gas pressure control system for existing semiconductor manufacturing processes. As Figure 1 shown, the gas pressure control system 1 for existing semiconductor manufacturing processes includes an air inlet 11, an air outlet 12, an operating air duct 13, and a bypass air duct 14. The two ends of the operating air duct 13 and the bypass air duct 14 are respectively connected to the air inlet 11 and the air outlet 12. The process equipment 10 and the equipment fan 15 are arranged in the operating air duct 13, and the bypass fan 16 is arranged in the bypass air duct 14.

[0003] The gas pressure control system 1 for existing semiconductor manufacturing processes is negative pressure relative to the external environment. When the process equipment 10 is operating, the equipment fan 15 rotates to introduce external gas from the air inlet 11 into the operating air duct 13. The gas passes through the process equipment 10 and the equipment fan 15 and is discharged from the air outlet 12. By controlling the rotation speed of the equipment fan 15, the negative pressure value of the air duct can be adjusted or maintained. When the process equipment 10 stops, the equipment fan 15 also stops operating. The bypass fan 16 rotates to introduce external gas from the air inlet 11 into the bypass air duct 14, and the gas is discharged from the air outlet 12. By controlling the rotation speed of the bypass fan 16, the negative pressure value of the air duct can be stabilized.

[0004] However, during the period when the state of the equipment fan 15 corresponding to the process equipment 10 changes from operation to stop or from stop to operation, the gas pressures of the gas pressure control system 1 for existing semiconductor manufacturing processes and the plant utility system will change significantly, indirectly affecting the pressures of the fans and other co-managed equipment in the plant utility system, and the stable operation of the bypass fan 16 also leads to increased energy consumption. How to solve various problems such as unstable negative pressure and increased energy consumption in the prior art is the main purpose of developing this application. Summary of the Utility Model

[0005] The technical problem to be solved by this application is to provide an air duct pressure control system, including: an air inlet, an air outlet, an operating air duct, a bypass air duct, and a variable-frequency fan. The two ends of the operating air duct and the bypass air duct are respectively connected to the air inlet and the air outlet, and the variable-frequency fan is arranged in the operating air duct; a pressure gauge is arranged in the air inlet and defaults a target pressure value to detect the pressure value of the gas in the air inlet; a first air damper and a second air damper are arranged in the operating air duct. The first air damper is located between the air inlet and the variable-frequency fan, and the second air damper is located between the variable-frequency fan and the air outlet; a third air damper and a fourth air damper are arranged in the bypass air duct. The third air damper is located between the air inlet and the fourth air damper; and a controller is connected to the variable-frequency fan, the pressure gauge, the first air damper, the second air damper, the third air damper, and the fourth air damper to control the operation or stop of the variable-frequency fan, the opening or closing of the first air damper, the second air damper, and the third air damper, and the maintenance or change of the opening of the fourth air damper, so that the pressure value of the gas in the air inlet reaches the target pressure value.

[0006] In one embodiment, the above-mentioned target pressure value is between -1 Pa and -5000 Pa.

[0007] In one embodiment, the above-mentioned controller is a programmable logic controller.

[0008] In one embodiment, when the above-mentioned controller controls the above-mentioned fourth air damper to maintain the opening, the opening of the above-mentioned fourth air damper is between 30% and 70%; when the above-mentioned controller controls the above-mentioned fourth air damper to change the opening, the opening of the above-mentioned fourth air damper changes by 0.1% to 5% per second.

[0009] The air duct pressure control system of this application includes an air inlet, an operating air duct, a bypass air duct, an air outlet, a pressure gauge, a variable-frequency fan, a first air damper, a second air damper, a third air damper, a fourth air damper, and a controller, and is applicable to the air duct pressure control method of this application. The pressure gauge defaults the target pressure value, the variable-frequency fan is linked with the process equipment, the controller can control the operating frequency of the variable-frequency fan, the first air damper, the second air damper, and the third air damper to switch the air duct for gas flow, and the fourth air damper to adjust the air duct pressure. There is no need to additionally set a fan in the bypass air duct. During the operation, stop, and conversion of the process equipment and the variable-frequency fan, the pressure value in the air duct can reach and stably maintain the target pressure value, which not only reduces the energy consumption of pressure control, but also makes the pressure of the plant system fan and other co-managed equipment not affected by the conversion of the operation / stop state of the process equipment and the variable-frequency fan in this system.

[0010] The other effects and detailed contents of the embodiments of this application are described below in conjunction with the drawings. Brief Description of the Drawings

[0011] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0012] Figure 1 is a block diagram of the gas system of the existing semiconductor manufacturing process;

[0013] Figure 2 is a block diagram of the air duct pressure control system according to an embodiment of the present application;

[0014] Figure 3 is a control result diagram of the air duct pressure control method according to an embodiment of the present application.

[0015] 1: Gas pressure control system of the existing semiconductor manufacturing process

[0016] 2: Air duct pressure control system 10, 20: Process equipment

[0017] 11, 21: Air inlet 12, 22: Air outlet

[0018] 13, 23: Operating air duct 14, 24: Bypass air duct

[0019] 15: Equipment fan 16: Bypass fan

[0020] 25: Variable frequency fan 26: Pressure gauge

[0021] 28: Controller 271: First air damper

[0022] 272: Second air damper 273: Third air damper

[0023] 274: Fourth air damper Detailed implementation manners

[0024] In the following implementation manners, the positional relationships described, including: up, down, left, and right, unless otherwise specified, are all based on the directions in which the components are shown in the drawings.

[0025] Figure 2 is a block diagram of the air duct pressure control system according to an embodiment of the present application. As Figure 2As shown in the figure, the air duct pressure control system 2 includes: an air inlet 21, an air outlet 22, an operating air duct 23, a bypass air duct 24, a variable-frequency fan 25, a pressure gauge 26, a first air damper 271, a second air damper 272, a third air damper 273, a fourth air damper 274, and a controller 28. The two ends of the operating air duct 23 and the bypass air duct 24 are respectively connected to the air inlet 21 and the air outlet 22. The pressure gauge 26 is arranged in the air inlet 21 and defaults to a target pressure value, used to detect the pressure value of the gas in the air inlet 21. The variable-frequency fan 25, the first air damper 271, and the second air damper 272 are arranged in the operating air duct 23. The first air damper 271 is located between the air inlet 21 and the variable-frequency fan 25, and the second air damper 272 is located between the variable-frequency fan 25 and the air outlet 22. The third air damper 273 and the fourth air damper 274 are arranged in the bypass air duct 24. The third air damper 273 is located between the air inlet 21 and the fourth air damper 274. The controller 28 is connected to the variable-frequency fan 25, the pressure gauge 26, the first air damper 271, the second air damper 272, the third air damper 273, and the fourth air damper 274, used to control the operation or stop of the variable-frequency fan 25, the opening or closing of the first air damper 271, the second air damper 272, and the third air damper 273, and the maintaining or changing of the opening degree of the fourth air damper 274, so that the pressure value of the gas in the air inlet 21 reaches the target pressure value.

[0026] In this embodiment, the process equipment 20 is arranged in the operating air duct 23. The variable-frequency fan 25 is interlocked with the process equipment 20. The pressure gauge 26 defaults the target pressure value of the air duct to a negative pressure, and the target pressure value is, for example, -1 Pa to -5000 Pa. The controller 28 can be a programmable logic controller (PLC). The first air damper 271, the second air damper 272, and the third air damper 273 are used to switch the air duct through which the gas flows. The fourth air damper 274 is a proportional air damper, used to control the air duct pressure. When the controller 28 controls the fourth air damper 274 to maintain the opening degree, the opening degree of the fourth air damper is between 30% and 70%. When the controller 28 controls the fourth air damper 274 to change the opening degree, the fourth air damper 274 changes the opening degree by 0.1% to 5% per second.

[0027] Based on the above air duct pressure control system, the present application provides an air duct pressure control method, including: pressure control in the operating state of the process equipment, pressure control when the process equipment is switched from the operating state to the stop state, pressure control in the stop state of the process equipment, and pressure control when the process equipment is switched from the stop state to the operating state.

[0028] Pressure control for the operating state of the process equipment: When the process equipment 20 and the variable-frequency fan 25 are operating, the controller 28 controls the opening of the first air damper 271 and the second air damper 272, the closing of the third air damper 273, the maintaining of the opening degree of the fourth air damper 274, and the operating frequency of the variable-frequency fan 25, so that the pressure value of the gas in the air inlet 21 reaches the target pressure value. Since the pressure in the air duct is negative relative to the external pressure, the gas outside the air inlet 21 flows through the air inlet 21 along the operating air duct 23 to the air outlet 22 and is discharged. After the pressure value of the gas in the air inlet 21 reaches the target pressure value, the controller 28 controls the change of the operating frequency of the variable-frequency fan 25, for example but not limited to, from 0.1 Hz to 5 Hz per second, so that the pressure value in the air duct is maintained at the target pressure value.

[0029] Pressure control for the process equipment to switch from the operating state to the stopped state: When the process equipment 20 switches from operating to stopped, the controller 28 controls the third air damper 273 to gradually open and the variable-frequency fan 25 to reduce the operating frequency; until the third air damper 273 is fully open, the controller 28 controls the variable-frequency fan 25 to stop, and the first air damper 271 and the second air damper 272 to close. During the period when the third air damper 273 changes from closed to fully open, the controller 28 controls the variable-frequency fan 25 to reduce the operating frequency at a rate of 0.1 Hz to 10 Hz per second.

[0030] Pressure control for the stopped state of the process equipment: When the process equipment 20 and the variable-frequency fan 25 are stopped, the first air damper 271 and the second air damper 272 are closed, the third air damper 273 is open, and the controller 28 controls the change of the opening degree of the fourth air damper 274, so that the pressure value of the gas in the air inlet 21 is maintained at the target pressure value. The gas outside the air inlet 21 flows through the air inlet 21 along the bypass air duct 24 to the air outlet 22 and is discharged.

[0031] Pressure control for the process equipment to switch from the stopped state to the operating state: When the process equipment 20 switches from stopped to operating, the controller 28 controls the change of the opening degree of the fourth air damper 274, the gradual opening of the first air damper 271 and the second air damper 272, the gradual closing of the third air damper 273, and the variable-frequency fan 25 to operate at the initial frequency; until the first air damper 271 and the second air damper 272 are fully open and the third air damper 273 is fully closed, the controller 28 controls the variable-frequency fan to operate in the pressure chasing mode, so that the pressure value of the gas in the air inlet reaches the target pressure value. The initial frequency of the operation of the variable-frequency fan 25 is, for example but not limited to, from 25 Hz to 60 Hz.

[0032] It should be noted that when the pressure gauge measures that the pressure value of the gas in the air duct reaches the target pressure value in this application, the difference between the actually measured pressure value by the pressure gauge and the target pressure value is within the allowable range, for example, the difference between the actually measured pressure value and the target pressure value is within 0% to 30% of the target pressure value, for example: 0% to 20%, 0% to 10%, 0% to 5%.

[0033] The air duct flow rate that can be controlled by the air duct pressure control system of the present application is, for example, 1 m 3 / h (Cubic Meter Per Hour, CMH) to 20000 m 3 / h, and it can be applied to the exhaust gas pipeline system of process equipment and the pipeline system of semiconductor factories. When the air duct pressure control system of the present application is actually used to control the air duct with a target pressure value of negative pressure 800 Pa, the control results are as Figure 3 shown.

[0034] Figure 3 In the figure, the left vertical axis indicates the air duct negative pressure value, the right vertical axis indicates the operating frequency of the variable frequency fan, and the horizontal axis indicates the measurement time. During the measurement period, the operating frequency of the variable frequency fan ranges from 0 Hz to 50 Hz. After 3 operation / stop conversion processes, the air duct negative pressure value remains within -800 Pa ± 30 Pa. In the initial state, the variable frequency fan is pre-started and operates at the initial frequency, and there is no obvious change in the pressure of the air duct; when the process equipment is switched from stop to operation, the third damper of the bypass air duct is closed, and the first and second dampers of the operating air duct are opened. Since the variable frequency fan operates in a pressure chasing mode, the pressure of the air duct drops instantaneously; during the operation of the process equipment, the operating frequency of the variable frequency fan is controlled to adjust the air duct pressure; when the process equipment is switched from operation to stop, the third damper of the bypass air duct is opened, the first and second dampers of the operating air duct are closed, the variable frequency fan stops, and the opening degree of the fourth damper is adjusted to maintain the air duct pressure at the target pressure value. From the control results, it can be seen that the air duct pressure control system of the present application can keep the air duct pressure stable during the conversion of operation / stop of the process equipment and the variable frequency fan. In the stop state, there is no need to set a fan in the bypass air duct, and the air duct pressure can still be maintained at the target pressure value, so that the pressure of the factory facility system fan and other co-managed equipment will not be affected by the conversion of operation / stop states of the process equipment and the variable frequency fan within this system.

[0035] In summary, the air duct pressure control system of the present application includes an air inlet, an operating air duct, a bypass air duct, an air outlet, a pressure gauge, a variable frequency fan, a first damper, a second damper, a third damper, a fourth damper, and a controller, and is applicable to the air duct pressure control method of the present application. The pressure gauge defaults the target pressure value, the variable frequency fan is linked with the process equipment, the controller can control the operating frequency of the variable frequency fan, the first, second, and third dampers to switch the air duct for gas flow, and the fourth damper to adjust the air duct pressure. There is no need to additionally set a fan in the bypass air duct. During the operation, stop, and conversion of the process equipment and the variable frequency fan, the pressure value in the air duct can reach and stably maintain at the target pressure value, which not only reduces the energy consumption of pressure control, but also makes the pressure of the factory facility system fan and other co-managed equipment not affected by the conversion of operation / stop states of the process equipment and the variable frequency fan within this system.

[0036] The above-described embodiments and / or implementation manners are merely used to illustrate the preferred embodiments and / or implementation manners for implementing the technology of this application, and do not impose any formal restrictions on the implementation manners of the technology of this application. Any person skilled in the art, without departing from the scope of the technical means disclosed in the content of this application, may make some modifications or refinements to other equivalent embodiments, but should still be regarded as the same technology or embodiment as this application in essence.

Claims

1. An air duct pressure control system, characterized in that: The air duct pressure control system comprises: An air inlet, an air outlet, a running air duct, a bypass air duct and a variable frequency fan, the two ends of the running air duct and the bypass air duct are respectively connected to the air inlet and the air outlet, and the variable frequency fan is arranged in the running air duct; A pressure gauge is disposed in the air inlet and is set to a target pressure value by default, so as to detect the pressure value of the gas in the air inlet; A first damper and a second damper are disposed in the operating air duct, the first damper is located between the air inlet and the variable frequency fan, and the second damper is located between the variable frequency fan and the air outlet; a third damper and a fourth damper, disposed in the bypass air duct, the third damper being located between the air inlet and the fourth damper; and A controller is connected to the variable frequency fan, the pressure gauge, the first damper, the second damper, the third damper and the fourth damper, and is used to control the operation or stop of the variable frequency fan, the opening or closing of the first damper, the second damper and the third damper, and the fourth damper to maintain or change the opening, so that the pressure value of the gas in the air inlet reaches the target pressure value.

2. The air duct pressure control system according to claim 1, characterized in that: The target pressure value is between -1Pa and -5000Pa.

3. The air duct pressure control system according to claim 1, characterized in that: The controller is a programmable logic controller.

Images