KR100874895B1 - Vacuum pressure controlling apparatus for use in semiconductor device fabrication - Google Patents

Abstract

The apparatus for controlling vacuum pressure which is suitable for the semiconductor device fabrication is provided to minimize the process contamination which can be generated in the chamber by precisely detecting the valve position value, the emergency signal. The apparatus for controlling vacuum pressure comprises the pressure control valve(200), and the valve controller(100). The pressure control valve is installed between the vacuum chamber(400) and vacuum pump(300). The pressure control valve is controlled by valve control signal to control the pressure within the vacuum chamber. The valve controller compares the valve setting value with the valve position value applied from the position sensor installed at the pressure control valve to recognize the malfunction of the valve operation to generate the interlock signal. The valve controller relieves the pressure signal from the pressure sensor installed at the vacuum chamber and checks the pressure of the chamber and applies the valve control signal to the pressure control valve.

Description

Vacuum pressure controlling apparatus suitable for semiconductor device fabrication

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of vacuum pressure control in chambers, and more particularly to a vacuum pressure control device suitable for the manufacture of semiconductor devices.

In general, in the semiconductor manufacturing process of forming a film on a wafer and etching in a set pattern, various kinds of processing gases are used for performing a process. The reaction gases are usually very toxic and fatal to the human body and may explode when mixed with other gases or air. Therefore, the treatment of the gases after the performance of the process is of considerable importance in terms of environmental safety. Most of the process gases used for semiconductor device manufacturing are treated on a process line to be discharged as harmless gases. That is, a semiconductor processing line is usually provided with a plurality of chambers (chambers) for processing a large amount of wafers, and each chamber is connected to a processing gas suction line and a clean gas suction line, and the discharge line of the chamber has a vacuum pump. Is installed. In addition, the exhaust line of the vacuum pump is connected to the combustion exhaust and the acid exhaust through the scrubber (scrubber) for the reaction gas incineration purification. When processing the wafer, a film is formed on the wafer by using flammable gas and highly corrosive acid gas.Cleaning the chamber after the first processing is completed using the combustible gas as described above, and again, acid gas for secondary processing. Is injected into the chamber. Nitrogen (N2) gas is used to clean the chamber. Nitrogen gas is discharged to the combustible exhaust part when cleaning residual flammable gas, and nitrogen gas is discharged to the acid exhaust part when cleaning residual acid gas. Here, the gas separation and discharge performed strictly in the semiconductor manufacturing process is performed depending on the operation of the gas valve. By replacing the existing bellows with a seal bushing with a double O-ring and forming a barrier film by injecting high pressure nitrogen between them, an improved gas valve is disclosed to prevent external leakage of gas and to facilitate maintenance and replacement. However, there is still a problem that it is difficult to know the operation state and the overhaul period of the valve precisely due to particles or residues attached to the valve. In addition, when a malfunction of such a gas valve occurs, wafer loss is caused due to contamination of the main chamber during a run of the main chamber, and thus there is a disadvantage in that process and operation efficiency are deteriorated.

Meanwhile, in a semiconductor manufacturing process such as a chemical vapor deposition (CVD) process, a pressure control valve for opening and closing the vacuum passage is almost essential between the vacuum chamber into which the wafers are introduced and the vacuum pump to make the inside of the vacuum chamber at a set air pressure. do. Such a pressure regulating valve is driven in response to a valve control signal applied from the valve controller, such that the pressure in the vacuum chamber is regulated to a preset pressure. A typical pressure regulating valve is a globe valve type having a bellows seal made of stainless steel in the valve housing. Malfunction detection devices of valve controllers which generate an interlock by sensing a malfunction state of the pressure regulating valve, also called a vacuum valve, are also known in the art. The malfunction detection device of such a valve controller adopts a method of generating an interlock when the open state detection signal is simply not fed back from a state detection sensor that detects an open / closed state of a valve opened and closed by air. That is, a malfunction detection apparatus of a conventional valve controller for generating an interlock when malfunctioning of the vacuum valve to prevent a process defect is generated from a valve driving control unit for generating a valve driving voltage in response to a predetermined control signal, and from the valve driving control unit. A solenoid drive unit for supplying / blocking air for opening / closing the valve by the generated valve driving voltage, a roughing valve opened and closed by air supplied from the solenoid drive unit, a sensor for detecting an open / closed state of the roughing valve; And a relay for driving the open state detection signal of the sensor to feed back the open state detection signal of the roughing valve to the valve driving control unit, and the open state detection signal of the roughing valve from the relay through the valve driving control unit. Including a controller that generates an interlock when not fed back The lure is.

Therefore, in the above-described conventional technology, the valve opening / closing position value of the valve is not monitored to detect an abnormal operation of the valve, but the time from when the switch connected to the porter coupler is turned on to the switch connected to the sensor of the valve. Because of the method of measuring and interlocking after a set time has elapsed, the reliability of the interlock of the valve controller is low, and if a particle or process by-product is attached to the valve shutoff and there is a minute vacuum leakage, There was a problem that was difficult to be accurate and accurate. In other words, when a minute leakage occurs due to a valve malfunction, an interlock may not be immediately generated, and an alarm may be generated after the wafer contamination has progressed considerably.

It would therefore be highly desirable to be able to promptly alert and take action in the event of a valve malfunction to minimize or reduce process contamination that may occur in the chamber.

Accordingly, an object of the present invention is to provide an air pressure control device suitable for manufacturing a semiconductor device.

Another object of the present invention is to provide a vacuum pressure control device suitable for manufacturing a semiconductor device capable of monitoring the valve opening and closing position value of the valve to detect abnormal valve operation.

It is still another object of the present invention to precisely monitor the valve opening and closing position to enable immediate alarm and action in the event of a valve malfunction, thereby minimizing or reducing process contamination that may occur in the chamber, and the resulting vacuum. To provide a pressure control method.

It is another object of the present invention to set and control the operation of the valve with an easy operation input, and to monitor the operation state of the valve according to the valve opening and closing position value and to self-diagnose and generate an interlock when determining malfunction, and at the same time, the equipment main management system It is to provide an improved valve controller that communicates with the host device in real time.

According to one aspect of the present invention for achieving the above object of the present invention, a vacuum pressure control device suitable for semiconductor device manufacturing:

A pressure regulating valve installed between the vacuum chamber and the vacuum pump, the pressure regulating valve being driven in response to an applied valve control signal to adjust the pressure in the vacuum chamber to a preset pressure;

When the pressure of the vacuum chamber is checked, the valve control signal generated according to the checked pressure is applied to the pressure regulating valve, and the valve opening / closing position value of the pressure regulating valve is monitored to deviate from a preset error value. It is equipped with a valve controller that detects an abnormal operation and generates an interlock signal.

In an embodiment of the present invention, the valve controller further includes a display unit for visually displaying state data related to valve operation of the pressure regulating valve, and an operation unit for performing menu hierarchical setting related to valve operation of the pressure regulating valve. It can be provided.

Preferably, the interlock signal may be transmitted to a host device for manufacturing the semiconductor device, and a valve opening / closing position value of the pressure regulating valve may be applied from a position sensor installed near an operating end of the pressure regulating valve. . In addition, the pressure of the vacuum chamber may be checked by at least two pressure sensors.

According to the vacuum pressure control device of the present invention as described above, since the valve opening and closing position value is accurately monitored, it is possible to quickly alarm and measure when the valve malfunctions, thereby minimizing or reducing process contamination that may occur in the chamber. . In addition, there is an advantage that it is easy to operate and set when controlling the valve and that the setting value can be easily confirmed without a separate key operation.

Hereinafter, according to the present invention, a preferred embodiment of a vacuum pressure control device suitable for manufacturing a semiconductor device will be described with reference to the accompanying drawings.

Although many specific details are described by way of example and in the following embodiments, it should be noted that this has been described without the intent to assist those of ordinary skill in the art to provide a more thorough understanding of the invention. . However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. Other illustrations, known methods, procedures, and electronic circuits for the operation and actuation of conventional vacuum valves have not been described in detail in order not to obscure the present invention.

First, the technical gist of the present invention will be briefly described in order to help understanding of the present invention. To the valve controller which checks the pressure of the vacuum chamber and applies the valve control signal generated according to the checked pressure to the pressure regulating valve, It precisely monitors the valve open / close position value of the pressure regulating valve to detect an abnormal operation of the valve and generate an interlock signal when it is out of the preset error value. In addition, an operation unit is also provided for performing menu hierarchical setting related to valve operation of the pressure regulating valve for ease of operation and setting. Here, the menu hierarchical setting means that submenus are listed at the bottom of a particular upper menu for reducing the number of push button keys and to facilitate input operation. It is the hierarchical menu structure listed again below.

First, Figure 1 is a schematic configuration diagram of a vacuum pressure control device according to an embodiment of the present invention. Referring to the drawings, the pressure in the vacuum chamber 400 is installed between the vacuum chamber 400 and the vacuum pump 300 by being driven in response to the valve control signal VCON applied through the line L1. The pressure control valve 200 is shown to be adjusted to the set pressure. The valve controller 100 connected to the pressure regulating valve 200 checks the pressure of the vacuum chamber 400 and outputs the valve control signal VCON generated according to the checked pressure to the pressure regulating valve 200. The valve opens and closes the valve opening and closing position value PF of the pressure regulating valve 200 to detect an abnormal valve operation and transmits an interlock signal INTL to the host equipment 500. .

The valve controller 100 may include a control unit 110, a valve driving unit 120, a display unit 130, a first sensing unit 140, an operation unit 150, a second sensing unit 160, and memories 170, 180, and 190. , And an input / output unit 195. That is, the valve controller 100 may further include a display unit for visually displaying state data related to valve operation of the pressure regulating valve 200. In addition, the operation unit 150 may be further provided to perform a menu hierarchical setting related to valve operation of the pressure regulating valve 200.

The controller 110 performs general control related to the monitoring of the pressure of the vacuum chamber and the operation of the pressure regulating valve and the driving according to a preset program. The RAM 170 connected to the controller 110 functions as a main memory. The flash memory 180 connected to the controller 110 functions as a nonvolatile memory and permanently stores the generation of the interlock signal and various history information until an erase command is given. The program that programmed the operation of the controller 110 is stored in the ROM 190. However, in other cases, the program may be stored in the flash memory 180.

The operation unit 150 connected to the control unit 110 includes pushbutton keys and state display lamps described in FIG. 7, and enables easy operation and setting by setting menu hierarchical settings related to valve operation of the pressure regulating valve. To the user.

The pressure regulating valve 200 is composed of a valve actuator unit 215 and a control valve unit 220, employing solenoid valves and the blocking unit 208 is provided at the operating end of the bellows 207 made of stainless steel The internal structure of the control valve 220 may be achieved. The sensor installed in the blocking unit 280 may be composed of a magnetic position sensor or a potentiometer. When employed as a magnetic position sensor, it can be implemented as a Hall effect linear position sensor. In the case where the potential meter is employed as a sensor, it is desirable to obtain a result of varying the output voltage value according to the degree of movement of the breaker by connecting to the breaker 280 or the shaft of the bellows. Here, the potential meter may have an output value of about 1.2 volts to about 4.8 volts when the valve close position moves in the range of 0-28 mm.

The host equipment 500 that receives the interlock signal INTL is connected to the vacuum chamber 400 through a line L12 and controls a process recipe for the vacuum chamber 400.

The pressure in the vacuum chamber 400 is checked by at least two pressure sensors 410 and 412. The first pressure sensor 410 is a low vacuum sensor for sensing a pressure of tens to hundreds of torr (torr), the second pressure sensor 412 is a high vacuum sensor for sensing a pressure of thousands of torr.

The valve 416 directly connected between the vacuum chamber 400 and the vacuum pump 300 without passing through the pressure regulating valve 200 is a bypass valve.

The first sensing unit 140 receives a valve closed position signal applied from the position sensor 210 installed in the pressure regulating valve 200 and converts the digital valve closed position data into digital valve closed position data. In addition, the second sensing unit 160 receives a pressure sensing signal applied from the pressure sensors 410 and 412 installed in the chamber 400 and converts the pressure sensing signal into digital pressure data. The valve driver 120 generates the valve control signal VCON in response to a valve driving command of the controller 110 and applies it to the pressure regulating valve 200.

The control unit 110 checks the pressure of the chamber based on the digital pressure data, applies the valve driving command to the valve driving unit 120 according to the checked pressure, and the digital valve close position data is preset. It monitors whether the error range value is exceeded and generates an interlock signal (INTL) when it exceeds.

FIG. 2 is a detailed block diagram of the pressure control valve of FIG. 1. Referring to the drawings, the electric field proportional valve 215c, the opening position control circuit 215a, the electric proportional valve driving circuit 215b, the first and second solenoid valves 225, 230, and the vacuum pressure control valve 220 . DC 24V is typically applied to the first and second solenoid valves 225 and 230 as a driving voltage. The configuration and operation of the pressure control valve shown in FIG. 2 are well known in the art, and thus, further description thereof will be omitted. However, the position sensor 210 is installed in the vacuum pressure control valve 220 of the structure as shown in FIG.

3 is a flow chart illustrating a valve operation control for generating an interlock signal according to FIG. 1. The subject performing the control flow in FIG. 3 is the controller 110. First, step 31 is a step in which initialization is performed. In this step, the controller 110 initializes an internal buffer, various registers, and flags for storing temporary storage data. Step 32 is a step of storing a valve close initial value. In other words, the reference value is set when the valve is closed. Step 33 is a step of checking whether the valve is closed under the operation mode. The purpose of the thirty-third step is to allow the interlock to be generated if there is an error in the closing operation after the valve closing operation is performed. Step 34 is a step of receiving a current valve close value. The current valve close value is a value sensed by the position sensor 210 and provided from the first sensing unit 140. Step 35 is a step of subtracting the initial value of the valve close from the received current valve close value to check whether the allowed error E is out of tolerance. Here, step 36 is immediately performed in the case of deviation from the allowable error. In step 36, an interlock signal is generated, and an alarm and display are performed. Step 37 is a step of storing a code value, in which the event occurrence history is coded and stored in various situations or interlocks. Step 38 is a step of checking whether to communicate with the host. Communication with the host may be performed by wire or wirelessly, and various control data as well as event occurrence history data may be transmitted and received. Step 39 is a step of transmitting the history code and the interlock generation result to the host.

4 is a control flow diagram of the valve position value setting according to FIG. 1. The control flow of FIG. 4 is performed by the controller 110 and is performed by the user pressing a key through the manipulation unit 150. First, step 41 is a key input scanning step. If scanning of the key input is started in step 42 and a specific key is pressed, it is checked in step 43 whether the angle key is pushed. In the 44th step, an operation of reading a current valve position value, reading a position related command, and storing the same is performed. Step 45 is a step of displaying the setting value and the driving value on the screen. Step 46 is to check whether there is an up / down key input. Step 47 is a step of displaying the setting up change value on the screen when the up key is input. In operation 48, when the down key is input, the setting down change value is displayed on the screen. Step 49 is a step of checking whether there is an input of the enter key, and if there is an input of the enter key, storing of the set data is performed.

5 is an exemplary view illustrating a display state of a display unit of FIG. 1. Referring to the screen state 50, it can be seen that the first and second pressures P1 and P2 are respectively 7.123 torr and 123.120 torr tr, and the valve position is 15.550 mm. Referring to screen state 54, it is shown that the valve position is 12.123 mm and the valve position setting is 00.000 mm. Referring to screen state 58, it is shown that the first pressure P1 is 7.123 Torr and the setting pressure is shown as 130.000 Pa.

6 is an exemplary diagram illustrating a storage data table of a memory of FIG. 1. In FIG. 6, reference numeral 60 denotes a valve operating initial value region. Reference numeral 62 denotes a valve closed primary value region, and reference numeral 64 denotes a valve closed secondary value region. Reference numeral 66 denotes an area of tolerance (E). Therefore, the measurement data displayed in the valve closed secondary value region is outside the tolerance (also called the management tolerance) value of 0.01 mm, and thus is subject to interlock generation. The storage data table is provided in the RAM 170, and the valve closing initial value and the allowable error data are information read from the flash memory 180. Although the tolerance value is set to 0.01 mm in the present embodiment, the tolerance value is not limited thereto, and the tolerance value may be arbitrarily set by the user according to the equipment used, the valve characteristic, and the process characteristic.

7 is a diagram illustrating an arrangement of buttons and a display lamp of the operation unit of FIG. 1. Referring to the drawings, full open 7a, full close 7b, angle 7c, slow vacuum 7d, P1 control 7e, P2 control 7f, forward direction 7g, reverse direction 7h, The keys for setting up 7i, down 7j, select 7k, and enter 7l are arranged on the left side in the figure. Further, in the drawing, light emitting lamps for showing the run 7m, the control 7n, the alarm 7o, and the error 7p as lamp display are arranged. On the other hand, unexplained reference numeral 7q is a changeover switch 7q necessary for switching the valve controller to a remote or local function. In this way, operation of a key required for valve control at the time of valve control in a local state is made as simple as possible. That is, the keys are located in front of the panel, thereby increasing the convenience of operation.

Hereinafter, an embodiment of the operation of the vacuum pressure control apparatus according to the present invention will be described with reference to the other figures with reference to Figs.

First, the setting operation for drive control is described, and then the process of generating an interlock in case of valve malfunction is described.

4, when the user presses the angle key 7c of the control panel 152 of FIG. 7, the control unit 110 of FIG. 1 continuously passes through the check step of step 43 and proceeds to steps 44 and 45. To do it. By performing the 45 th step, the screen state 54 of FIG. 5 is displayed on the screen of the display unit 130 of FIG. 1. As such, when the valve control value of the current state according to the control mode and the setting value for the control are displayed together on one screen, the difference between the actual driving value is directly confirmed and the convenience of operation is facilitated. In addition, in the case of displaying the screen state 58, the offset setting screen is displayed together with the pressure control so that the value can be easily checked by modifying the offset when the control is completed without going to the mode. Therefore, the inconvenience of having to operate the key separately to confirm the drive value is displayed by displaying the actual drive value required for valve control on one screen.

After the 45th step is performed, in the local mode of the controller, the user operates the up / down keys 7i and 7j of FIG. 7 and presses the enter key 7l after completion of the setting, and the control flow of FIG. This completes the setting of the desired pressure value or valve closing initial value. That is, registration of reference data is achieved by the control flow of FIG.

Reference is now made to FIG. 3.

When the valve close is performed in step 33 of FIG. 3 during the pressure monitoring, the controller 110 receives the current valve close value through the first sensing unit 140 (step 34). And step 35 is performed. In step 35, the received valve close position value and the valve close setting value may be compared to check whether an error value deviates from a preset error value. Here, as shown in the table area 64 of FIG. 6, when the measurement data displayed in the valve closed secondary value area is out of the tolerance 0.01 mm compared to the reference data, it becomes an object of interlock generation. That is, when the valve closing operation is not completed due to the particle or by-products attached to the inside of the valve, there is a leak. Accordingly, when the valve closing position is out of the allowable error, an interlock signal is immediately generated in step 36, and an alarm and display are performed. Thereafter, in operation 37, an event occurrence history is encoded and stored when various situations or interlocks occur. In addition, when communication with the host is required in operation 38, various control data as well as event occurrence history data are performed in operation 39.

Eventually, the valve controller receives the pressure value measured from the pressure sensor and detects whether a pressure difference greater than a predetermined value is generated, performs a basic pressure monitoring operation that generates a warning sound and a warning display control signal, and monitors the valve close position in real time. If it is out of the set position error limit, it detects an abnormal valve operation and generates an interlock signal. Accordingly, the state of the vacuum valve is always self-diagnosed and preventive maintenance can be performed at an appropriate time, thereby reducing damage to various related components and loss of wafers. That is, the damage of the chamber, the vacuum pump, and the valve is minimized, so that the life time is relatively long as the deterioration phenomenon (breakage, wear) is reduced, so that the loss of component elements and wafers is reduced. It is reduced.

Preferably, the valve position tolerance values can be precisely classified so that interlock can be performed at check, risk, and high risk levels. For example, if it is within the range of 0-20% within the tolerance range, check it, if it is within the range of 50% to 50%, and if it is within the range of 50% to 100%, it will give a high warning. Accordingly, in the case of high risk, all the operation of the equipment is stopped, and the external warning light or the overhaul light emitting diode is turned on or the buzzer is sounded to detect an abnormal condition so that the user can promptly follow up.

Therefore, the self-diagnosis function can determine whether there is an abnormality of the valve and prevent the loss of the wafer, and can prevent the contamination of the chamber by blocking at the time of operation or emergency, thereby increasing the efficiency of the process and operation.

In the above description, the embodiments of the present invention have been described with reference to the drawings, for example. However, it will be apparent to those skilled in the art that the present invention may be variously modified or changed within the scope of the technical idea of the present invention. . For example, if the matter is different, the signal form of the interlock may be changed, or the function of the operation unit and the display method of the display unit may be variously modified or changed without departing from the technical spirit of the present invention.

1 is a schematic configuration diagram of a vacuum pressure control device according to an embodiment of the present invention

Figure 2 is a specific block diagram of the pressure control valve of Figure 1

3 is a flow chart illustrating a valve operation control for generating an interlock signal according to FIG. 1.

4 is a flow chart illustrating a setting operation for setting a valve position value according to FIG.

5 is an exemplary view illustrating a display state of a display unit in FIG. 1.

6 is an exemplary view illustrating a storage data table of a memory of FIG. 1.

7 is a diagram illustrating an arrangement of buttons and an indicator lamp of an operation unit of FIG. 1;

Claims (15)

In the vacuum pressure control device used in the manufacture of semiconductor devices: A pressure regulating valve installed between the vacuum chamber and the vacuum pump, the pressure regulating valve being driven in response to an applied valve control signal to adjust the pressure in the vacuum chamber to a preset pressure; Receives a pressure sensing signal from the pressure sensor installed in the vacuum chamber to check the pressure in the vacuum chamber, generates the valve control signal according to the checked pressure to apply to the pressure regulating valve, the position installed on the pressure regulating valve And a valve controller which detects an abnormal valve operation and generates an interlock signal when the valve opening / closing position value applied from the sensor is compared with the valve opening / closing setting value and is out of a predetermined error value. The vacuum pressure control apparatus of claim 1, wherein the valve controller further comprises a display unit for visually displaying state data related to valve operation of the pressure regulating valve. The vacuum pressure control apparatus according to claim 1, wherein the valve controller further comprises an operation unit for performing menu hierarchical setting related to valve operation of the pressure regulating valve. The apparatus of claim 1, wherein the interlock signal is transmitted to a host device for manufacturing the semiconductor device. 5. The vacuum pressure control device according to claim 4, wherein the position sensor is installed at an operating end of the pressure regulating valve. 6. The vacuum pressure control device as claimed in claim 5, wherein the pressure of the vacuum chamber is checked by at least two pressure sensors. In the air pressure control device used in the manufacture of semiconductor devices: A pressure regulating valve disposed between the chamber and the pump, the pressure regulating valve being driven in response to an applied valve control signal to adjust the pressure in the chamber to a preset pressure; Receives a pressure sensing signal from the pressure sensor installed in the chamber and checks the pressure in the chamber, generates the valve control signal according to the checked pressure and applies it to the pressure regulating valve, from the position sensor installed in the pressure regulating valve And a valve controller which detects an abnormal operation of the valve and generates an interlock signal when an applied valve close position value is compared with a valve close setting value and is out of a preset error value. 8. The air pressure control device according to claim 7, wherein the valve controller further comprises an operation unit for performing menu hierarchical setting related to valve operation of the pressure regulating valve. The air pressure control apparatus of claim 8, wherein the interlock signal is transmitted to a host device for manufacturing the semiconductor device. The air pressure control apparatus as claimed in claim 9, wherein the position sensor is a magnetic position sensor installed at a cutoff portion of the pressure regulating valve. The air pressure control device according to claim 9, wherein the position sensor is a potential meter connected to a bellows end of the pressure regulating valve. 12. The air pressure control device of claim 11, wherein the pressure in the chamber is checked by at least two pressure sensors. The air pressure control device of claim 12, wherein the valve controller further comprises a liquid crystal display for visually displaying state data related to valve operation of the pressure regulating valve. A valve controller for controlling a pressure regulating valve installed between a chamber and a pump and driven in response to an applied valve control signal to adjust the pressure in the chamber to a preset pressure: A second sensing unit receiving a pressure sensing signal applied from a pressure sensor installed in the chamber and converting the pressure sensing signal into digital pressure data; A first sensing unit configured to receive a valve close position signal applied from a position sensor installed in the pressure regulating valve and convert the valve closed position signal into digital valve closed position data; A valve driving unit generating the valve control signal in response to a valve driving command and applying the same to the pressure regulating valve; The pressure of the chamber is checked based on the digital pressure data, and the valve driving command is applied to the valve driving unit according to the checked pressure, and whether the digital valve close position data exceeds a preset error range value. And a control unit for generating an interlock signal when exceeded. A valve control method in an air pressure control device having a pressure control valve installed between a chamber and a pump: Preparing a pressure sensor for sensing a pressure in the chamber and a position sensor for sensing a valve close position of the pressure regulating valve; A valve driving step of checking the pressure sensor so that the pressure in the chamber is adjusted to a preset pressure; Receiving a valve closed position value from the position sensor when the pressure regulating valve is closed; And comparing the received valve close position value with the valve close setting value and generating an interlock signal when a predetermined error value is out of the range.

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