JP2021127750A - Pump monitoring device and vacuum pump - Google Patents

Abstract

To provide a pump monitoring device capable of preventing wrong determination upon determining abnormality of a vacuum pump.SOLUTION: A pump monitoring device 5 of a vacuum pump 1 that exhausts a process chamber in which the same process is repeated multiple times in a chronological order, comprises: a data acquisition unit 51 that acquires a motor current value of the vacuum pump 1; a calculation unit 52 that generates actual measurement waveform data representing the time-series change of the motor current value, based on the acquired motor current value; and a display control unit 53 that for multiple processes, forms each actual measurement waveform image based on the actual measurement waveform data for one process period from the start to the end of the process, and displays the plurality of actual measurement waveform images on one display screen of a display device 54 in a preset display format.SELECTED DRAWING: Figure 3

Description

The present invention relates to a pump monitoring device and a vacuum pump.

In processes such as dry etching and CVD in the manufacture of semiconductors and liquid crystal panels, process gas is introduced while exhausting the process chamber with a vacuum pump to maintain a predetermined process pressure for processing. When the gas in the process chamber such as dry etching or CVD is exhausted, the reaction product is deposited in the pump as the gas is exhausted.

Regarding the deposition of such reaction products, Patent Document 1 discloses a deposit detection device that detects the products deposited in the pump. The deposit detection device disclosed in Patent Document 1 performs the following processing to issue a warning. That is, the motor current value is read a plurality of times within a predetermined time in the initial processing, and the total value thereof is divided by the number of readings to obtain the motor current initial value. Similarly, the motor current value is read a plurality of times within a predetermined time in the post-processing, and the total value thereof is divided by the number of readings to obtain the current motor current value. A warning is issued by comparing the amount of change in motor current obtained by subtracting the initial value of motor current from the current value of motor current with the warning level value.

Japanese Patent No. 5767632

However, in reality, since the flow rate of the exhaust gas fluctuates greatly even within a single process, the current value of the motor that rotationally drives the rotating body also fluctuates greatly as the gas flow rate fluctuates. Therefore, erroneous judgment is unavoidable.

The pump monitoring device according to the aspect of the present invention is a pump monitoring device for a vacuum pump that exhausts a process chamber in which the same process is repeated a plurality of times in a time series, and acquires a physical quantity representing the operating state of the vacuum pump. The acquisition unit, the calculation unit that generates actual measurement waveform data representing the time-series change of the physical quantity based on the acquired physical quantity, and the plurality of the processes are set within one process period from the start to the end of the process. It is provided with a display control unit that forms an actually measured waveform image based on the actually measured waveform data for a predetermined period and displays the plurality of actually measured waveform images on one display screen of the display device in a preset display format.
A vacuum pump according to an aspect of the present invention includes a rotor, a stator, and a pump body having a motor for rotationally driving the rotor, and a pump controller including the pump monitoring device and driving and controlling the motor.

According to the present invention, it is possible to prevent erroneous determination when determining an abnormality of the vacuum pump.

FIG. 1 is a diagram showing a schematic configuration of a vacuum processing device equipped with a pump monitoring device according to an embodiment. FIG. 2 is a cross-sectional view showing the details of the pump body. FIG. 3 is a block diagram showing a configuration of a vacuum pump and a configuration of a monitoring device. FIG. 4 is a diagram showing an example of a time-series waveform of the motor current value. FIG. 5 is a flowchart showing an example of data generation processing. FIG. 6 is a flowchart showing an example of the display control process. FIG. 7 is a diagram showing an image display in the display format A. FIG. 8 is a diagram showing an image display in the display format B. FIG. 9 is a diagram showing an image display in the display format C. FIG. 10 is a diagram showing an image display in the display format C. FIG. 11 is a diagram showing a peak hold display. FIG. 12 is a diagram showing a modified example of the display format A. FIG. 13 is a block diagram showing a configuration when the pump controller is responsible for the monitoring function.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a vacuum processing device 10 equipped with a pump monitoring device according to an embodiment. The vacuum processing apparatus 10 is, for example, an etching processing apparatus or a film forming processing apparatus. The vacuum pump 1 is attached to the process chamber 2 via a valve 3. The vacuum pump 1 includes a pump main body 11 and a pump controller 12 that drives and controls the pump main body 11. A monitoring device 5 for monitoring the state of the vacuum pump 1 is connected to the pump controller 12. In the example shown in FIG. 1, the monitoring device 5 is connected to one pump controller 12, but it may be connected to a plurality of pump controllers 12 to monitor a plurality of vacuum pumps 1. ..

The vacuum processing device 10 includes a main controller 100 that controls the entire vacuum processing device 10 including the vacuum pump 1 and the valve 3. The pump controller 12, the valve 3, and the monitoring device 5 of the vacuum pump 1 are connected to the main controller 100 via the communication line 40. The monitoring device 5 monitors whether or not the vacuum pump 1 is abnormal. An example of a pump abnormality in the present specification is a case where the amount of reaction products deposited inside the pump body 11 exceeds the permissible amount.

FIG. 2 is a cross-sectional view showing the details of the pump main body 11. The vacuum pump 1 in the present embodiment is a magnetic bearing type turbo molecular pump, and the pump main body 11 is provided with a rotating body R which is magnetically levitated and supported by the magnetic bearing. The rotating body R includes a pump rotor 14 and a rotor shaft 15 fastened to the pump rotor 14.

In the pump rotor 14, rotary blades 14a are formed in a plurality of stages on the upstream side, and a cylindrical portion 14b forming a screw groove pump is formed on the downstream side. Corresponding to these, a plurality of stages of fixed wing stator 62 and a cylindrical screw stator 64 are provided on the fixed side. There are two types, one is a type in which a screw groove is formed on the inner peripheral surface of the screw stator 64, and the other is a type in which a screw groove is formed on the outer peripheral surface of the cylindrical portion 4b. Each fixed wing stator 62 is mounted on the base 60 via a spacer ring 63.

The rotor shaft 15 is magnetically levitated and supported by radial magnetic bearings 17A and 17B provided on the base 60 and axial magnetic bearings 17C, and is rotationally driven by a motor 16. Each of the magnetic bearings 17A to 17C includes an electromagnet and a displacement sensor, and the displacement sensor detects the floating position of the rotor shaft 15. The rotation speed of the rotor shaft 15 is detected by the rotation speed sensor 18. When the magnetic bearings 17A to 17C are not operating, the rotor shaft 15 is supported by emergency mechanical bearings 66a, 66b. In the magnetic bearings 17A to 17C of the present embodiment, the floating position of the rotor shaft 15 is detected by a dedicated displacement sensor, but instead of the dedicated displacement sensor, the sensor carrier component is superimposed on the electromagnet current and displaced. It may be a self-sensing type (also called a sensorless type) magnetic bearing that detects the displacement.

A pump casing 61 in which an intake port 61a is formed is bolted to the base 60. An exhaust port 65 is provided in the exhaust port 60a of the base 60, and an auxiliary pump is connected to the exhaust port 65. When the rotor shaft 15 to which the pump rotor 14 is fastened is rotated at high speed by the motor 16, gas molecules on the intake port 61a side are exhausted to the exhaust port 65 side.

The base 60 is provided with a heater 19 and a refrigerant pipe 20 through which a refrigerant such as cooling water flows. A refrigerant supply pipe (not shown) is connected to the refrigerant pipe 20, and the flow rate of the refrigerant to the refrigerant pipe 20 can be adjusted by controlling the opening and closing of the electromagnetic on-off valve installed in the refrigerant supply pipe. When exhausting a gas in which reaction products are likely to accumulate, the heater 19 is turned on and off and the refrigerant pipe 20 flows in order to suppress the accumulation of products on the thread groove pump portion and the rotary blade 14a on the downstream side. By turning the flow rate of the refrigerant on and off, for example, the temperature is adjusted so that the base temperature near the screw stator fixing portion becomes a predetermined temperature.

FIG. 3 is a block diagram showing the configuration of the vacuum pump 1 and the configuration of the monitoring device 5. As shown in FIG. 2, the pump body 11 of the vacuum pump 1 includes a motor 16, a magnetic bearing (MB) 17, and a rotation speed sensor 18. The pump controller 12 includes a magnetic bearing control unit (MB control unit) 22 and a motor control unit 23. In FIG. 3, the radial magnetic bearings 17A and 17B and the axial magnetic bearing 17C of FIG. 2 are collectively referred to as a magnetic bearing 17.

The motor control unit 23 estimates the rotation speed of the rotor shaft 15 based on the rotation signal detected by the rotation speed sensor 18, and feedback-controls the motor 16 to a predetermined target rotation speed based on the estimated rotation speed. As the gas flow rate increases, the load on the pump rotor 14 increases, so that the rotation speed of the motor 16 decreases. The motor control unit 23 maintains a predetermined target rotation speed (rated rotation speed) by controlling the motor current so that the difference between the rotation speed detected by the rotation speed sensor 18 and the predetermined target rotation speed becomes zero. I am trying to do it. In this way, in a state where a series of processes are being performed, the motor control unit 23 performs steady operation control for maintaining the rotation speed at the rated rotation speed. The magnetic bearing 17 includes a bearing electromagnet and a displacement sensor for detecting the floating position of the rotor shaft 15.

The monitoring device 5 is a device that monitors the state of the vacuum pump 1 attached to the process chamber 2. The monitoring device 5 includes a data acquisition unit 51, a calculation unit 52, a display unit 54, a display control unit 53, an operation unit 55 for a user to input a command to the monitoring device 5, and a storage unit 56. ing. The monitoring device 5 includes a CPU, a memory such as a RAM or ROM constituting the storage unit 56, and a recording medium such as a hard disk. The CPU functions as a data acquisition unit 51, a calculation unit 52, and a display control unit 53 according to a program stored in the storage unit 56.

The display unit 54 may be provided separately from the monitoring device 5. Further, as shown in FIG. 13, the data acquisition unit 51, the calculation unit 52, the display control unit 53, the operation unit 55, and the storage unit 56 may be incorporated into the pump controller 12, and the function of the monitoring device 5 may be assigned to the pump controller 12. .. Furthermore, the waveform image data or the like may be output from the monitoring device 5 to the main controller 100, and the waveform image may be displayed on the display unit of the main controller 100, or the main controller 100 may include the monitoring device 5. ..

In the present embodiment, a case where the motor current value of the vacuum pump 1 is used as the physical quantity for monitoring the vacuum pump 1 will be described. The data acquisition unit 51 acquires the motor current value detected by the motor control unit 23 from the pump controller 12. The motor current value is acquired at a predetermined sampling interval set in advance. The calculation unit 52 generates actual measurement waveform data, reference waveform data, peak hold waveform data, etc. of the motor current value, which will be described later, based on the motor current value acquired by the data acquisition unit 51. The display control unit 53 displays an image based on the data generated by the calculation unit 52 on the display unit 54 in a display format based on a user command input via the operation unit 55. The storage unit 56 stores the data acquired by the data acquisition unit 51, the data generated by the calculation unit 52, the above-mentioned program, and the like.

FIG. 4 is a diagram showing an example of a time-series waveform of a motor current value when the same vacuum processing process, for example, an etching process is continuously repeated for a plurality of substrates in the vacuum processing apparatus 10. The process for the first substrate is performed in the period P1 of times t1 to t2, the process for the second substrate is performed in the period P2 of times t2 to t3, and the process for the third substrate is performed in the period P3 of times t3 to t4. The process for the substrate takes place. Since the same process is repeated, the time-series waveforms of the motor current values of P1 to P3 in each period are almost the same waveforms. In the following, this period will be referred to as the process period.

At time t1, when the first substrate is carried into the process chamber 2 and the process chamber 2 is exhausted by the vacuum pump 1, the motor current value rises sharply, and the motor current value reaches its maximum value at time t1a and drops to time t1b. do. After that, the process gas is introduced from the time t1b, the motor current value rises, and reaches the maximum value at the time t1c. From time t1c to time t1d, the process process is performed with a constant process pressure, so that the motor current value becomes constant. When the process process for the first substrate is completed at time t1d and the introduction of the process gas is stopped, the motor current value drops sharply and drops to the position at time t1e. After that, the motor current value has two peaks at time t1f and t1g, and rapidly decreases from the peak at time t1g to the value at time t2. During this time, the first substrate is carried out and the second substrate is carried in. At the process period P2 for the second substrate starting at time t2 and the process period P3 for the third substrate starting at time t3, the motor current value shows the same change as the process period P1.

In FIG. 4, the waveform shown by the solid line L1 is the waveform of the measured motor current value (hereinafter referred to as the measured waveform), and the waveform shown by the broken line L2 is the waveform of the motor current value used as the reference for comparison (hereinafter referred to as the reference waveform). Call). The process process is started after the vacuum pump 1 is started and reaches the rated rotation speed. As will be described later, the reference waveform is set based on the motor current value acquired in a plurality of process processes within a predetermined period after the start of pump operation. The predetermined period is set in the initial period after the start of pump operation in which almost no product accumulation occurs.

(Generation of reference waveform data and measured waveform data)
FIG. 5 is a flowchart showing an example of data generation processing in the calculation unit 52 of the monitoring device 5. This procedure is executed by starting the data generation processing program stored in the storage unit 56 when the monitoring device 5 is started. The data generated by the calculation unit 52 includes, for example, measured waveform data (L1 in FIG. 4) based on the measured motor current value and waveform data processed and generated based on the measured waveform data. As the waveform data generated by processing, the reference waveform data (L2 in FIG. 4) generated by performing the averaging process and the data showing the peak hold waveform of the measured waveform data sequentially generated (FIG. 11 (a) described later). ), Lph) in FIG. 11 (b), and the like. In FIG. 5, a case where actually measured waveform data and reference waveform data are generated is shown as an example.

When the vacuum pump 1 is started by a command from the main controller 100 of the vacuum processing device 10, the monitoring device 5 is also started with the start of the vacuum pump 1. When the monitoring device 5 is activated, the treatment program shown in FIG. 5 is executed. In step S1, it is determined whether or not the rotor rotation drive of the vacuum pump 1 has been started, that is, whether or not the vacuum pump 1 has been started. If it is determined in step S1 that the rotor rotation drive has been started, the process proceeds to step S2 to start sampling the motor current value. The sampled motor current value is stored in the storage unit 56. In step S3, it is determined whether or not N process periods have elapsed since the sampling of the motor current value was started. That is, it is determined whether or not the motor current values for the N process period required for generating the reference waveform data have been sampled.

In FIG. 4, it is assumed that the rotation of the vacuum pump 1 is started and the first process is started at t = t1. During the process period, a plurality of minimum values occur in the motor current value, but the smallest minimum value (I≈I ₀ ) occurs at time t1, t2, t3, t4 ... Since this minimum value I ≈ I ₀ is acquired at the start of each process period as shown in FIG. 4, when the minimum value I ≈ I ₀ is obtained three times, the motor current value data for two process periods is obtained. Is sampled. For example, assuming that the motor current value data for N processes is required to generate the reference waveform data, the motor current value data _{sampled until the minimum value I ≈ I 0} is obtained (N + 1) times is used as the reference waveform data. Used for generation. That is, in step S3, when the number of sampled motor current value data of the current value I ≈ I ₀ becomes (N + 1), it is determined as yes.

When it is determined in step S3 that the motor current value data for the N process period has been acquired, the process proceeds to step S4 to determine the time Δt for one process period. Specifically, since the acquisition time interval of the motor current value data in which the current value I ≈ I _{0 corresponds to the time Δt in one process period, the sampling time of the (N + 1) th current value I ≈ I 0} and the first sampling time. By multiplying the difference value from the sampling time of the current value I ≈ I ₀ by 1 / N, the time Δt of one process period is calculated. The calculated time Δt of one process period is stored in the storage unit 56.

In step S5, reference waveform data is generated based on the motor current value data for the N process period stored in the storage unit 56. First, the motor current value data for the N process period is grouped into the motor current value data for each process period. That is, a plurality of motor current value data acquired from the time when the current value I ≈ I ₀ is acquired until the time Δt of one process period elapses are grouped as the motor current value data of one process period. Then, for N motor current value data groups for N process period, for example, one process averaged by taking an average value between the motor current value acquisition data of the same sampling timing within the process period. The motor current value data group for the period can be obtained. The motor current value data group for this one process period corresponds to the reference waveform data. The calculated reference waveform data is stored in the storage unit 56.

In step S6, the measured waveform data is generated by grouping the plurality of motor current value data sampled and stored in the storage unit 56 into the motor current value data group for each process period. That is, a plurality of motor current value data acquired from the sampling time of the motor current value data of the current value I ≈ I ₀ until the time Δt of one process period elapses are grouped as a motor current value data group of one process period. To become. This grouped motor current value data group corresponds to the actually measured waveform data.

In step S7, it is determined whether or not the vacuum pump 1 has been stopped. In step S7, if it is determined that the vacuum pump 1 is not stopped, the process returns to step S6, and if it is determined that the pump is stopped, a series of data processing is terminated. That is, the measured waveform data generation process is repeatedly executed until the series of process processes in the vacuum processing apparatus 10 are stopped and the vacuum pump is stopped. Then, each time a new motor current value data group for one process period is acquired, the measured waveform data for a new one process period is calculated and stored in the storage unit 56.

The determination of whether or not the vacuum pump 1 has been stopped is determined by, for example, detecting that the sampled motor current value has become zero, thereby determining that the pump has stopped. Further, the pump start and pump stop signals may be input from the main controller 100, and the pump stop may be determined by receiving the pump stop signal.

(Explanation of image display on the display unit 54)
The display control unit 53 (see FIG. 3) of the monitoring device 5 controls the display of the display image on the display unit 54 based on the generated monitoring image data. The display control unit 53 displays the display image on the display unit 54 in a display format based on the display command input by the user operating the operation unit 55.

FIG. 6 is a flowchart showing an example of display control processing by the display control unit 53. This procedure is executed by activating the display control program stored in the storage unit 56 with the activation of the monitoring device 5. In FIG. 6, a case where there are three types of display formats A, B, and C is shown as an example.

In step S10, it is determined whether or not the input display command is the display format A. If it is determined in step S10 that the display command is in the display format A, the process proceeds to step S11 to display the waveform image in the display format A. If it is determined in step S10 that the display command is other than the display format A, the process proceeds to step S12 to determine whether or not the display command is the display format B. If it is determined in step S12 that the display command is the display format B, the process proceeds to step S13 to display the waveform image in the display format B. If it is determined in step S12 that the display command is other than the display format B, the process proceeds to step S14 to display the waveform image in the display format C.

In the example shown in FIG. 6, one of a plurality of display formats A to C is selected and displayed based on the display command from the operation unit 55, but one of the display formats is used. It may be configured to display only. For example, a monitoring device that can only display in the display format A may be used.

FIG. 7 is a diagram showing an image display in the display format A. In the display format A, three actually measured waveforms L13, L12, and L11 dating from the present to the past are displayed side by side in the left-right direction of the display screen 54a, which is the display area of the display unit 54, as waveform images No. 1 to No. 3. ing. The waveform image No. 1 is the latest measured waveform L13 obtained most recently, the measured waveform L12 one cycle past is displayed as waveform image No. 2 on the left side, and the measured waveform L11 two cycles past is further left side. Is displayed as waveform image No. 3. When a new measured waveform (represented as the measured waveform L14) after one cycle of the measured waveform L13 is newly obtained from the state shown in FIG. 7, the measured waveform L14 is displayed as the waveform image No. 1 and the waveform image No. The measured waveforms L13 and L12 are displayed as .2 and No. 3, respectively.

In FIG. 7, the actually measured waveforms L11 and L13 have substantially the same waveform shape, but the shape of the portion indicated by reference numeral 543 in the actually measured waveform L12 is different from that of the other actually measured waveforms L11. By observing and comparing the three actually measured waveforms L13, L12, and L11, the user determines whether or not an abnormality has occurred in the pump based on the difference in the actually measured waveforms. For example, it is determined whether the product deposition is within the permissible range. When determining a waveform abnormality from such a displayed image, the entire waveform during the process period can be visually compared, so that the difference can be easily made regardless of the region of the process period. Can be found in. Therefore, it is possible to prevent the pump abnormality from being overlooked.

On the other hand, in the conventional technique described in Patent Document 1, in each of the initial processing and the post-processing, the average value of the motor current values acquired a plurality of times within a predetermined time of the process period is obtained, and the difference between them is the motor current. A warning is issued by comparing the amount of change with the warning level value. Therefore, even if a situation occurs in which the amount of change in the motor current becomes large in a period other than the predetermined time, it will be overlooked. However, in the present embodiment, the entire waveform of the process period is compared as an image as described above. This makes it possible to prevent erroneous determination due to oversight as in the past.

In FIG. 7, touch panel type operation buttons 55a, 55b, 55c are displayed as the operation unit 55 in the lower region in the display screen 54a. The operation button 55a is an operation button that returns the display state by one cycle. When the operation button 55a is pressed once in the display state of FIG. 7, the measured waveforms of the past for one cycle as waveform images No. 1 to No. 3, that is, one cycle before the measured waveforms L12 and L11 and the measured waveform L11. The measured waveforms obtained in are displayed in order as waveform images No. 1, No. 2, and No. 3. From that state, when the operation button 55c that advances the measured waveform by one cycle is operated, the display state of FIG. 7 is restored.

In the latest display state of FIG. 7, since the (future) display state beyond that state cannot be displayed, the operation button 55c is indicated by a broken line to indicate that the operation is not possible. Further, the operation button 55b is an operation button for returning to the latest display state. After changing the display state by operating the operation buttons 55a or 55c, pressing the operation button 55b returns to the latest display state (display state in FIG. 7).

FIG. 8 is a diagram showing an image display in the display format B. In the display format B, three waveform images No. 1, No. 2, and No. 3 dating back from the present to the past are displayed so as to be superimposed on the same display area. In FIG. 8, the overlapping waveform images No. 1 to No. 3 are displayed in a staggered manner so that they can be recognized. The measured waveform L13 is displayed in the waveform image No. 1, the measured waveform L12 is displayed in the waveform image No. 2, and the measured waveform L11 is displayed in the waveform image No.3. In this case, since a plurality of actually measured waveforms L11 to L13 to be compared are displayed in an overlapping manner, it becomes easier to distinguish the difference in waveform shape as compared with the case where the measured waveforms L11 to L13 are displayed side by side as shown in FIG. When the operation button 55a is pressed in the display state of FIG. 8, the display goes back by one cycle, and instead of the measured waveforms L13, L12, and L11, the measured waveforms L12 and L11 and the measured waveform one cycle before the measured waveform L11. Is displayed as waveform images No. 1 to No. 3.

FIG. 9 is a diagram showing an image display in the display format C. In the display format C, the waveform image No. 1 in which the actually measured waveform is displayed and the waveform image No. 2 in which the reference waveform L2 is displayed are superimposed and displayed. In the example shown in FIG. 9, the most recent measured waveform L13 is displayed in the waveform image No.1. In the display format C, the measured waveform is compared and displayed with the reference waveform L2 in the initial state of using the pump, which has almost no product deposition. The transition can be easily recognized. When the operation button 55a is pressed in the display state of FIG. 9, the measured waveform L12 one cycle before is displayed as the waveform image No. 1 as shown in FIG. The waveform image No. 2 remains the reference waveform L2.

In FIG. 10, the operation button 55c is indicated by a solid line, indicating that the operation button 55c can be operated. In the example shown in FIGS. 9 and 10, the waveform image No. 2 in which the reference waveform L2 is displayed is superimposed on the one waveform image No. 1 in which the actually measured waveform is displayed. The waveform image in which the reference waveform L2 is displayed may be superimposed on the plurality of waveform images in which the actual measured waveform is displayed.

The display format for displaying the plurality of waveform images on the display unit 54 is not limited to the display formats A to C described above, and various forms are possible. For example, instead of displaying a plurality of waveform images at the same time as shown in FIG. 8, the plurality of waveform images may be displayed in order at predetermined time intervals (for example, 1 second intervals) that are easy to visually compare. At that time, the reference waveform L2 may also be displayed as shown in FIGS. 9 and 10.

Further, the waveform image in which the peak hold waveform Lph as shown in FIG. 11 is displayed may be displayed as one of the reference waveform images. The peak hold waveform data, which is the data of the peak hold waveform Lph, is generated by the calculation unit 52. In FIG. 11A, the waveform image No. 1 in which the peak hold waveform Lph is displayed, the waveform image No. 2 in which the measured waveform L11 is displayed, and the waveform image No. 3 in which the reference waveform L2 is displayed are shown. It is displayed in an overlapping manner. In FIG. 11B, the waveform image No. 1 in which the peak hold waveform Lph is displayed, the waveform image No. 2 in which the measured waveform L12 is displayed, and the waveform image No. 3 in which the reference waveform L2 is displayed are shown. It is displayed in an overlapping manner. FIG. 11A is a display at the time t when the measured waveform L11 is acquired, and FIG. 11B is a display at the time t + Δt when the measured waveform L12 after one cycle is acquired.

FIG. 11A shows a case where the value (current value) of the portion of the actually measured waveform L11 indicated by the reference numeral p10 is larger than the value of the peak hold waveform before the actually measured waveform L11 is obtained. Therefore, since the actually measured waveform L11 is obtained, the value of the region indicated by the reference numeral p10 of the peak hold waveform Lph is updated to the value of the actually measured waveform L11. Further, when the measured waveform L12 of FIG. 11B is obtained, the value of the region shown by p11 of the measured waveform L12 is larger than the value of the peak hold waveform Lph of FIG. 11A in the same region. Therefore, in the peak hold waveform Lph of FIG. 11 (b), the value (waveform) of the region indicated by the reference numeral p11 is updated with respect to the peak hold waveform Lph shown in FIG. 11 (a).

As described above, the peak hold waveform Lph is a waveform composed of peak values at each time in the process period at each time of the actually measured waveform from the start of measurement to the present. By displaying the peak hold waveform Lph, it is possible to easily recognize the transition of the increase in the motor current value due to the accumulation of the product.

(Modification example 1)
The display format shown in FIG. 12 is a modification of the display format A shown in FIG. 7. In the display format shown in FIG. 12, 10 measured waveforms L11 to L20 from the latest measured waveform L20 to the measured waveform L11 retroactively are displayed as shown in FIGS. 12 (a) to 12 (c). When a predetermined time (for example, 1 second) has elapsed from the display of FIG. 12 (a), the display is switched to the display of FIG. 12 (b), and when the predetermined time is further elapsed, the display is switched to the display of FIG. 12 (c). In FIG. 12A, the actually measured waveforms L20, L19, and L18 are displayed as waveform images No. 1, No. 2, and No. 3 in order from the right side of the drawing. In FIG. 12B, the measured waveforms L19, L18, and L17 one cycle before each of the measured waveforms L20, L19, and L18 are displayed as waveform images No. 1, No. 2, and No. 3. ing. Further, in FIG. 12C, the actually measured waveforms L18, L17, and L16 one cycle before each of the actually measured waveforms L19, L18, and L17 are designated as waveform images No. 1, No. 2, and No. 3. It is displayed.

In the display format shown in FIG. 12, each time a predetermined time elapses, the measured waveforms one cycle before are displayed as waveform images No. 1, No. 2, and No. 3, and finally FIG. 12 (a). ) Is displayed for a time of (predetermined time) × 7, and the actually measured waveforms L13, L12, and L11 are displayed as waveform images No. 1, No. 2, and No. 3. As a result, the actually measured waveforms L11 to L20 of 20 can be visually compared.

As a modification of the display format B shown in FIG. 8, a plurality of actually measured waveforms L11, L12, and L13 may be displayed in chronological order at predetermined time intervals.

In the above-described embodiment, a plurality of waveform images displayed on the display unit 54 are visually observed to determine a pump abnormality. However, the monitoring device 5 is provided with a pump abnormality determination unit, and the pump abnormality determination unit compares the waveform shape of the waveform image (for example, the waveform shape of the measured waveform data and the waveform shape of the reference waveform data) over the entire process period. A pump abnormality may be determined based on the difference in waveform shape.

(Modification 2)
As the physical quantity for monitoring the vacuum pump 1, not only the above-mentioned motor current value but also the motor rotation speed, the control current value of the magnetic bearing control, and the like can be used. These physical quantities can be used as indicators of changes in pump load due to product deposition.

(Modification example 3)
In the above-described embodiment, the reference waveform data is generated based on the motor current value data for the N process period obtained after the process is started, stored in the storage unit 56, and the reference waveform is based on the reference waveform data. L2 is displayed. This reference waveform L2 can be used as the reference waveform L2 after the start of the process after the next pump maintenance. That is, if the process is started after the pump maintenance, the reference waveform L2 is displayed by the reference waveform data stored in the storage unit 56 and compared with the measured waveform.

It will be understood by those skilled in the art that the above-described exemplary embodiments and modifications are specific examples of the following embodiments.

[1] The pump monitoring device according to one aspect is a pump monitoring device for a vacuum pump that exhausts a process chamber in which the same process is repeated a plurality of times in a time series, and a physical quantity representing an operating state of the vacuum pump is obtained. The acquisition unit to be acquired, the calculation unit that generates the measured waveform data representing the time-series change of the physical quantity based on the acquired physical quantity, and the plurality of the processes within one process period from the start to the end of the process. It is provided with a display control unit that forms each of the actually measured waveform images based on the actually measured waveform data for a predetermined period of time and displays the plurality of actually measured waveform images on one display screen of the display device in a preset display format.

For example, in the monitoring device 5, the data acquisition unit 51, the calculation unit 52, and the display control unit 53 correspond to the acquisition unit, the calculation unit, and the display control unit. Since the display control unit 53 displays a plurality of waveform images No. 1 to No. 3 as shown in FIG. 7 on the display screen 54a of the display unit 54, the entire waveform is observed and the plurality of waveform images are compared. Can be done. As a result, when the difference in waveform shape is in any region of the process period, the difference can be easily found and the oversight of the pump abnormality can be prevented.

In the above-described embodiment, the one process period (periods P1, P2, P3, etc. in FIG. 4) itself is used as the predetermined period set within the one process period, but for example, within the one process period in FIG. The period corresponding to the time t1 to the time t1e may be set as a predetermined period.

[2] In the pump monitoring device according to the above [1], the display control unit has a plurality of display formats as the preset display formats, and one of the plurality of display formats is displayed. It is provided with a setting unit for setting as a display format to be displayed on one display screen of the device. For example, as shown in FIG. 6, by setting any of the display formats A to C to be displayable according to the display command, it is possible to select a display format that is easier to compare.

[3] In the pump monitoring device according to the above [1] or [2], the display format to be displayed on the display device is such that a plurality of actually measured waveform images relating to the plurality of processes are displayed on one display screen of the display device. A first display format for displaying side by side, a second display format for displaying a plurality of actually measured waveform images related to a plurality of the processes on one display screen of the display device on a common time axis, and the process. This is one of the third display formats in which a plurality of the actually measured waveform image and the reference waveform image as a comparison reference with respect to the actually measured waveform image are superimposed and displayed on one display screen of the display device on a common time axis.

For example, the display format A shown in FIG. 7 corresponds to the first display format, the display format B shown in FIG. 8 corresponds to the second display format, and the display format C shown in FIG. 9 corresponds to the third display format. In the display format A of FIG. 7, the actually measured waveforms L13, L12, and L3 based on the motor current values acquired in one process period are displayed side by side on one display screen 54a. Therefore, it is easy to compare the motor current values at the same process timing, and it is easy to find the difference. Further, as in the display format B shown in FIG. 8, by superimposing and displaying a plurality of waveform images No. 1 to No. 3 on one display screen 54a on a common time axis, the difference in waveform is conspicuous. appear. Further, as in the display format C of FIG. 9, the waveform image No. 1 in which the measured waveform L13 is displayed and the waveform image No. 2 in which the reference waveform L2 is displayed are displayed on one display screen 54a on a common time axis. By displaying them in an overlapping manner, it is possible to easily recognize the state and transition of the product accumulation state from the deviation of the measured waveform from the reference waveform L2. Of course, the waveform of the period in which the difference in the motor current value is likely to occur within one process period may be displayed instead of the entire one process period.

[4] In the pump monitoring device according to the above [3], the calculation unit further generates reference waveform data in one process period based on actual measurement waveform data in a plurality of process periods within a predetermined predetermined period. , The display control unit displays the reference waveform image based on the reference waveform data. Since the reference waveform data is calculated based on the measured waveform data of the plurality of process periods and the reference waveform image is displayed based on the reference waveform data, it is not necessary to set the reference waveform image in advance.

[5] In the pump monitoring device according to the above [3], the calculation unit extracts the maximum physical quantity from a plurality of physical quantities at the same process timing from the measured waveform data of a plurality of different process periods, and the peak is obtained. The hold waveform data is further generated, and the display control unit displays the reference waveform image based on the peak hold waveform data. For example, as shown in FIG. 11A, the product is produced by superimposing the waveform image No. 1 on which the peak hold waveform Lph is displayed and the waveform image No. 2 on which the measured waveform L11 is displayed. The transition of the increase in the motor current value due to the deposition can be easily recognized.

[6] In the pump monitoring device according to any one of the above [1] to [5], the physical quantity is the current value of the motor that rotationally drives the rotor of the vacuum pump, or supports the rotor. It is a rotor displacement measured value in a magnetic bearing. Since the current value of the motor changes due to product deposition, the state of product deposition can be appropriately grasped by using the motor current value as a physical quantity. Further, the change in the rotor position due to the accumulation of the product may be detected by using the rotor displacement measurement values in the magnetic bearings 17A to 17C, and the rotor displacement measurement value may be used as a physical quantity instead of the motor current value.

[7] The vacuum pump according to one aspect includes a pump main body having a rotor, a stator, and a motor for rotationally driving the rotor, and a pump controller including the pump monitoring device and driving and controlling the motor.

In the above, the increase in the pump load caused by the adhesion of the impurity component of the process gas to the rotor or the like has been described as an example. However, as in the present invention, the device for monitoring the pump abnormality due to the increase in the pump load by comparing the reference waveform and the actually measured waveform is not limited to the increase in the pump load due to the accumulation of the product, but the pump load due to other factors. It can also be applied when monitoring an increasing number of events.

Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other aspects conceivable within the scope of the technical idea of the present invention are also included within the scope of the present invention.

1 ... Vacuum pump, 2 ... Process chamber, 5 ... Monitoring device, 10 ... Vacuum processing device, 11 ... Pump body, 12 ... Pump controller, 14 ... Pump rotor, 16 ... Motor, 51 ... Data acquisition unit, 52 ... Calculation unit , 53 ... Display control unit, 54 ... Display unit, 54a ... Display screen, 55 ... Operation unit, 56 ... Storage unit, 62 ... Fixed wing stator, 64 ... Screw stator, 100 ... Main controller

Claims (7)

A vacuum pump pump monitoring device that exhausts a process chamber in which the same process is repeated multiple times in chronological order.
An acquisition unit that acquires a physical quantity that represents the operating state of the vacuum pump, and
Based on the acquired physical quantity, a calculation unit that generates actual measurement waveform data representing a time-series change of the physical quantity, and
For each of the plurality of said processes, an actually measured waveform image based on the actually measured waveform data of a predetermined period set within one process period from the start to the end of the process is formed, and the plurality of actually measured waveform images are displayed in a preset state. A pump monitoring device including a display control unit that displays on one display screen of the display device in a format. In the pump monitoring device according to claim 1,
The display control unit has a plurality of display formats as the preset display format.
A pump monitoring device including a setting unit for setting one of the plurality of display formats as a display format to be displayed on one display screen of the display device. In the pump monitoring device according to claim 1 or 2.
The display format to be displayed on the display device is
A first display format, in which a plurality of actually measured waveform images related to the plurality of processes are displayed side by side on one display screen of the display device.
A second display format, in which a plurality of actually measured waveform images related to the plurality of processes are superimposed and displayed on one display screen of the display device on a common time axis.
And any of the third display formats in which a plurality of actually measured waveform images related to the process and a reference waveform image as a comparison reference with respect to the actually measured waveform image are superimposed and displayed on one display screen of the display device on a common time axis. A pump monitoring device. In the pump monitoring device according to claim 3,
The calculation unit further generates reference waveform data in one process period based on measured waveform data in a plurality of predetermined process periods.
The display control unit is a pump monitoring device that displays the reference waveform image based on the reference waveform data. In the pump monitoring device according to claim 3,
The calculation unit acquires peak hold waveform data obtained by extracting the maximum physical quantity among the plurality of physical quantities at the same time in one process period over one process period with respect to the plurality of processes.
The display control unit is a pump monitoring device that displays the reference waveform image based on the peak hold waveform data. In the pump monitoring device according to any one of claims 1 to 5.
The physical quantity is a current value of a motor that rotationally drives the rotor of the vacuum pump, or a rotor displacement measurement value of a magnetic bearing that supports the rotor, which is a pump monitoring device. A pump body having a rotor, a stator, and a motor that drives the rotor to rotate,
A vacuum pump including the pump monitoring device according to any one of claims 1 to 6, comprising a pump controller for driving and controlling the motor.

Images