Wireless communication system, wireless communication method, control device, and control method

Abstract

To provide a technique that allows data to be synchronously transmitted to a plurality of second devices when periodic data is transmitted from a first device to the plurality of second devices by wireless communication.SOLUTION: A wireless transmission system that transmits periodic data from a first device to a plurality of second devices by wireless communication includes a first wireless device connected to the first device and a plurality of second wireless devices connected to the respective second devices. The first wireless device includes a first wireless unit that performs wireless communication, and a first control unit that controls the first wireless unit. Each of the second wireless devices includes a second wireless unit that performs wireless communication and a second control unit that controls the second wireless unit. The first control unit and the second control units synchronize the first wireless device and the plurality of second wireless devices if the time from when the first wireless device transmits periodic data from the first device until the first wireless device receives responses from the second wireless devices is less than or equal to a set value.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system, a wireless communication method, a control device, and a control method.

Background Art

[0002] Patent Document 1 discloses a time-synchronizable wireless communication system including a first wireless device and a second wireless device. The wireless unit of the first wireless device separately wirelessly transmits timing information and duration information related to a transmission time which is the time obtained from a first clock and at which the timing information is transmitted. The wireless unit of the second wireless device separately receives the wirelessly transmitted timing information and time information. The second wireless device has a correction unit that corrects the second clock based on a reference time which is the time indicated by the second clock when the wireless unit receives the timing information and a transmission time obtained from the time information.

[0003] The technology of this Patent Document 1 suppresses the occurrence of uncertainty in the time related to communication due to autonomous transmission waiting and automatic retransmission control that frequently occur in communication wireless standards such as wireless LAN.

[0004] By the way, when periodically transmitting data by wireless communication from a first device to a plurality of second devices, it may be required to transmit synchronized data to the plurality of second devices. However, the technology of Patent Document 1 suppresses the occurrence of uncertainty in the time related to communication, and does not consider the point of synchronously transmitting data to a plurality of devices.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] This disclosure provides a technology that enables synchronization between a first device and multiple second devices when wireless communication is performed from a first device to multiple second devices. [Means for solving the problem]

[0007] A wireless communication system according to one aspect of this disclosure transmits wireless communication from a first device to a plurality of second devices. Periodic data A wireless communication system for transmitting a signal, comprising: a first wireless device connected to the first device; and a plurality of second wireless devices connected to each of the plurality of second devices, wherein the first wireless device comprises: a first wireless unit for performing wireless communication; and a first control unit for controlling the first wireless unit; and the second wireless device comprises: a second wireless unit for performing wireless communication; and a second control unit for controlling the second wireless unit. That was, Synchronize the first wireless device with the plurality of second wireless devices. It controls it in that way. , The first control unit creates data by adding a first timer value to the periodic data, measures the response time from when the first wireless device transmits the data to the second wireless device until it receives a response from the second wireless device to the data, determines whether the response time is less than or equal to a set value, and if it is less than or equal to the set value, transmits a flag along with the data to the second wireless device, records the difference between the second timer value of the second wireless device and the first timer value when the second wireless device receives the data transmitted from the first wireless device, and when the second wireless device receives the data along with the flag, rewrites the second timer value based on the difference, thereby establishing a synchronization relationship between the first wireless device and the plurality of second wireless devices. . [Effects of the Invention]

[0008] According to this disclosure, a technology is provided that enables synchronization between the first device and multiple second devices when wireless communication is performed from the first device to multiple second devices. [Brief explanation of the drawing]

[0009] [Figure 1] Block diagram showing a wireless communication system. [Figure 2] This diagram illustrates the process of sending 128 bytes of data at 10ms intervals using Wi-Fi. [Figure 3] This figure shows the time it takes for data to reach the client (CL) when an access point (AP) sends 128 bytes of data at 10ms intervals for approximately one hour. [Figure 4] This diagram shows a specific flow of wireless communication operation in one embodiment of a wireless communication system. [Figure 5]This is a cross-sectional view showing a substrate processing apparatus using a control device having a wireless communication system as one embodiment. [Figure 6] Figure 5 is a schematic diagram showing the overall control system, including a control device for controlling the substrate processing apparatus shown in Figure 5. [Figure 7] This diagram illustrates the process of a control controller (MC) sending control data to end devices connected to multiple I / O boards, and the MC receiving the responses. [Figure 8] This chart shows the experimental results confirming synchronization errors. [Figure 9] This chart shows the experimental results of confirming synchronization using a wireless communication system according to one embodiment. [Modes for carrying out the invention]

[0010] The embodiments will be described below with reference to the attached drawings.

[0011] <Wireless communication system> Figure 1 is a block diagram showing a wireless communication system according to one embodiment. The wireless communication system 100 of this embodiment transmits periodic data wirelessly from a first device 400 to a plurality of second devices 500. In the illustrated example, four second devices 500 are shown, but any number of second devices is acceptable.

[0012] In this embodiment, the target wireless communication standard is not particularly limited as long as it is one that causes instability in periodic communication, as will be described later. Major examples include 2.4GHz and 5GHz band communication standards such as Wi-Fi, Zigbee, Bluetooth, and BLE.

[0013] The wireless communication system 100 includes a first wireless device 200 connected to a first device 400 and a plurality of second wireless devices 300 respectively connected to a plurality of second devices 500. The first device 400 and the second devices 500 are, for example, control devices that control a controlled object, and it is exemplified that a control signal is transmitted as periodic data from the first device 400, which is a higher-level control device, to the plurality of second devices 500, which are lower-level control devices, to control the controlled object connected to the second device 500.

[0014] The first wireless device 200 is, for example, an access point (AP), and includes a first wireless section 201 that converts data into radio waves for wireless communication, and a first control section 202 that controls the wireless communication of the first wireless section 201. Also, the second wireless device 300 is, for example, a client (CL), and includes a second wireless section 301 that converts data into radio waves for wireless communication, and a second control section 302 that controls the second wireless section 301. Actual wireless communication is performed between the first wireless section 201 and the second wireless section 301.

[0015] When the time from when the first control section 202 and the second control section 302 transmit periodic data from the first wireless device 200 until the first wireless device 200 receives a response from the second wireless device 300 is equal to or less than a set value, the first wireless device 200 and the second wireless device 300 are synchronized.

[0016] That is, the first control section 202 creates data with a timer value added to the periodic data from the first device 400, and measures the response time from when the first wireless device 200 transmits the data until the first wireless device 200 receives a response from the second wireless device 300. Then, it determines whether the response time is equal to or less than the set value, and if it is equal to or less than the set value, it transmits a flag to the second wireless device 300 together with the data.

[0017] On the other hand, when the second control unit 302 receives the periodic data transmitted from the first wireless device 200, the second control unit 302 records the difference between the first timer value of the first wireless device 200 and the second timer value of the second wireless device 300. Then, when the second wireless device 300 receives data from the first wireless device 200 together with a flag indicating that the response time is equal to or less than a set value, the second control unit 302 rewrites the second timer value based on the difference to establish a synchronization relationship between the first wireless device 200 and the plurality of second wireless devices 300.

[0018] The wireless communication system 100 may be a multicast that simultaneously transmits data from the first wireless device 200 to a plurality of second wireless devices 300, or may be a unicast that sequentially transmits data from the first wireless device 200 to the plurality of second wireless devices 300 one by one.

[0019] This will be specifically described below. The first control unit 202 includes a first timer 203, a transmission data generation unit 204, a reception data monitor unit 205, a reception data determination unit 206, and a flag generation unit 207.

[0020] The first timer 203 measures the time in the first wireless device 200. The transmission data generation unit 204 generates data obtained by adding the first timer value of the first timer 203 to the periodic data from the first device 400. The reception data monitor unit 205 monitors the response time from when the first wireless device 200 transmits data until it receives a response from the second wireless device 300. The reception data determination unit 206 determines whether or not the response time monitored by the reception data monitor unit 205 is equal to or less than a set value. The flag generation unit 207 generates an OK flag 1 when the response time is equal to or less than the set value, and sets it to NG and generates a flag 0 (does not generate a flag) when it exceeds the set value.

[0021] The set value is appropriately configured to ensure synchronization between the first wireless device 200 and the multiple second wireless devices 300. As a set value, for example, the shortest time determined based on design values ​​or actual values ​​plus a given margin (e.g., shortest time + 2%) can be used. Alternatively, the set value may be determined by statistical processing based on actual values. For example, it may be the mean or median value obtained by statistical processing from actual values.

[0022] The transmission data generation unit 204 generates data with the information of flag 1 added to the data of the next cycle if flag 1 is generated, and generates data with flag 0 as the data of the next cycle if flag 0 is generated.

[0023] Each second control unit 302 includes a second timer 303, a timer value recording unit 304, a flag determination unit 305, and a timer value rewriting unit 306.

[0024] The second timer 303 measures time in the second wireless device 300. When the second wireless device 300 receives data transmitted from the first wireless device 200, the timer value recording unit 304 records the difference between the second timer value of the second timer 303 and the first timer value of the received data. The flag determination unit 305 determines the flag information of the received data. When the timer value rewriting unit 306 receives data with flag 1, it rewrites the second timer value to a value obtained by subtracting the difference recorded in the timer value recording unit 304 before the data with flag 1 was recorded from the second timer value at that time. At this time, a difference of 0 is recorded in the timer value recording unit 304.

[0025] In other words, if the received data has flag 1, it indicates that the previously received data showed that the first wireless device 200 received a response within the set time, and that data is reliable. Therefore, the difference value previously recorded in the timer value recording unit 304 is also a reliable value. Accordingly, as described above, the first wireless device 200 and the multiple second wireless devices 300 can be synchronized by rewriting the second timer value of the second timer 303 using the timer value rewriting unit 306. In this way, by synchronizing the first wireless device 200 and the multiple second wireless devices 300, the multiple second wireless devices 300 can also be synchronized among themselves.

[0026] If data with flag 0 is received, the difference is recorded in the timer value recording unit 304 based on the above calculation, but this record is discarded after the difference of the data for the next period is recorded.

[0027] Next, we will specifically describe the wireless communication operation in the wireless communication system 100 configured in this way.

[0028] Wireless communication eliminates the need for signal cables used in wired communication, allowing for smaller equipment and contributing to environmental protection by reducing the amount of wire used. However, when transmitting periodic data in wireless communication—specifically, data (packets) of a fixed size at regular intervals—variations in communication time can occur due to ambient disturbances or deterioration of the communication environment. Such problems do not typically occur in wired communication.

[0029] For example, when sending 128 bytes of data at 10ms intervals using Wi-Fi, as shown in Figure 2, the measured data will look like Figure 3. Figure 3 shows the time it takes for data to reach the client (CL) when 128 bytes of data are sent from an access point (AP) at 10ms intervals for approximately one hour, with a magnified portion of the data shown. As shown in Figure 3, the average data arrival time is about 10ms, but this value varies greatly from 2 to 35ms, indicating that the data arrival time is unstable.

[0030] When data arrival times are unstable in this way, it is difficult to synchronize data from the first device 400 to multiple second devices 500 using the wireless communication system 100, for example, to transmit it simultaneously.

[0031] Therefore, in the wireless communication system 100 according to this embodiment, the first control unit 202 and the second control unit 302 synchronize the first wireless device 200 with the multiple second wireless devices 300 when the time from when the first wireless device 200 transmits periodic data from the first device 400 until the first wireless device 200 receives a response from the second wireless devices 300 is less than or equal to a set value.

[0032] Specifically, first, data is created by adding a first timer value to the periodic data from the first device 400, and the response time from when the first wireless device 200 transmits this data until the first wireless device 200 receives a response from the second wireless device 300 is measured.

[0033] Next, it is determined whether the response time is less than or equal to the set value. If it is less than or equal to the set value, a flag is sent to the second wireless device 300 along with data containing the first timer value.

[0034] After the second wireless device 300 receives data containing the first timer value transmitted from the first wireless device 200, it records the difference between the first timer value and the second timer value.

[0035] Next, when the second wireless device 300 receives a flag along with data from the first wireless device 200, it rewrites the second timer value based on the difference between the first timer value and the second timer value, thereby establishing a synchronization relationship between the first wireless device 200 and the multiple second wireless devices 300. This allows the multiple second wireless devices 300 to synchronize, and periodic data from the first device 400 can be transmitted to the multiple second devices 500 in a synchronized manner, for example, simultaneously.

[0036] The specific flow will be explained below with reference to Figure 4. Here, we will explain using an example where the first wireless device 200 is an access point (AP) and multiple second wireless devices 300 are clients (CLs), and data is transmitted from the first device 400 at 10ms intervals.

[0037] First, the initial data from the first device 400 is transmitted from AP200 to CL300. At this time, the first timer value of AP200's first timer 203 is 11ms, and the transmission data generation unit 204 generates data with the first timer value of 11ms superimposed and transmits it.

[0038] In CL300, when the timer value of the second timer 303 is 55ms, it receives the first data transmitted from AP200 and responds to the first radio device 200. At this time, the timer value recording unit 304 of CL300 records the difference between the second timer value of the second timer 303 and the first timer value of the received data, i.e., 55ms - 11ms = 44ms.

[0039] Upon receiving a response, AP200 monitors the time from data transmission to receiving a response from CL300 using the received data monitor unit 205, and the received data determination unit 206 determines whether the time monitored by the received data monitor unit 205 to receiving the response is less than or equal to a set value. In this case, the set value (shortest time + 2%) is 1.95ms, but the time to receive the response is longer than the set value, for example, 5ms, so the received data determination unit 206 determines it as NG, and the flag generation unit 207 sets the flag to 0.

[0040] Next, the following data from the first device 400 is transmitted from AP200 to CL300. The time at this point is 10ms after the first data, and the first timer value of AP200's first timer 203 is 21ms. The transmission data generation unit 204 generates and transmits data that incorporates the first timer value of 21ms and reflects the previous flag of 0.

[0041] In CL300, when the timer value of the second timer 303 is 65ms, it receives the following data and responds to the first wireless device 200. At this time, the timer value recording unit 304 of CL300 records the difference between the second timer value of the second timer 303 and the first timer value of the received data, i.e., 65ms - 21ms = 44ms, and discards the previous difference record.

[0042] In AP200, which has received a response, the received data monitor unit 205 similarly monitors the time from when it sends the data until it receives a response from CL300, and the received data determination unit 206 determines whether the time until the response is received is less than or equal to a set value. In this case, since the time until the response is received is less than or equal to the set value, the received data determination unit 206 determines it to be OK, and the flag generation unit 207 generates flag 1.

[0043] Next, the following data from the first device 400 is transmitted from AP200 to CL300. The time at this point is 10ms after the previous data, and the value of AP200's first timer 203 is 31ms. The transmission data generation unit 204 adds the first timer value of 31ms and flag 1 and transmits the data.

[0044] In CL300, when the second timer value of the second timer 303 is 75ms, the next data described above is received and a response is sent to the first wireless device 200. At this time, the flag determination unit 305 determines that the received data has flag 1 attached, and the timer value rewriting unit 306 rewrites the second timer value of the second timer 303 to a value obtained by subtracting the difference value recorded in the timer value recording unit 304 from the second timer value of the second timer 303 at that time, i.e., 75ms - 44ms = 31ms. At this time, a difference of 0 (31ms - 31ms = 0ms) is recorded in the timer value recording unit 304 in preparation for the next flag.

[0045] In AP200, which has received a response, the received data monitor unit 205 similarly monitors the time from when it sends the data until it receives a response from CL300, and the received data determination unit 206 confirms that the time until it receives the response is less than or equal to a set value.

[0046] In this way, when AP200 receives data and receives a response within the set time, it generates flag 1. When transmitting data again, flag 1 is added to the data, and based on that data, the second timer value of the second timer 303 is rewritten to a value obtained by subtracting the difference value recorded in the timer value recording unit 304 from the second timer value at that time. By doing this for multiple CL300s, AP200 and multiple CL300s can be synchronized, and synchronization can be achieved between multiple CL300s. Therefore, periodic data from the first device 400 can be synchronized and transmitted, for example, simultaneously, to multiple second devices 500.

[0047] Furthermore, when the first device 400 and the second device 500 are control devices, synchronization errors may occur between multiple second devices 500 due to variations in the oscillator (clock) having a crystal oscillator, which is the time reference within the control device. However, as will be described later, the wireless communication system 100 of this embodiment can suppress synchronization errors.

[0048] This synchronization error occurs due to the accumulation of small errors over a long period of time. However, in this embodiment, if communication is established within a set time or less as described above, even for a short period of time, the wireless communication system 100 can establish synchronization among the multiple second devices 500, thereby suppressing instability and synchronization errors in periodic communication.

[0049] <Substrate Processing Equipment> Next, a substrate processing apparatus using a control device with the wireless communication system described above will be explained. Here, as an example of a substrate processing apparatus, a film deposition apparatus that forms a film on a substrate by ALD using a source gas and a reaction gas will be shown, but it is not limited to this.

[0050] Figure 5 is a cross-sectional view showing a substrate processing apparatus using a control device having a wireless communication system according to one embodiment. As shown in Figure 5, the substrate processing apparatus 600 has a substrate processing unit 700 and a control device 800.

[0051] The substrate processing unit 700 includes a processing container 1, a mounting table 2, a shower head 3, a gas supply unit 4, and an exhaust unit 5.

[0052] The processing container 1 is made of a metal such as aluminum and has a substantially cylindrical shape. An inlet / outlet (not shown) for loading and unloading substrates W is formed in the side wall of the processing container 1, and the inlet / outlet can be opened and closed with a gate valve (not shown). An exhaust port 1a is also provided at the bottom of the processing container 1.

[0053] The mounting table 2 is a disc-shaped plate the size of the substrate W, and is installed horizontally inside the processing container 1 and supported by a support member 21. The mounting table 2 is made of a ceramic material such as aluminum nitride (AlN) or a metallic material such as aluminum or nickel-based alloy, and has a heater (not shown) embedded inside for heating the substrate W. The heater is heated by power supplied from a heater power supply (not shown). A temperature sensor 24 is provided near the top surface of the mounting table 2, and the temperature of the substrate W is controlled by controlling the output of the heater using the temperature sensor.

[0054] The support member 21 extends from the center of the bottom surface of the mounting table 2, through a hole formed in the bottom wall of the processing container 1, and downwards to the processing container 1, with its lower end connected to the lifting mechanism 22. The lifting mechanism 22 allows the mounting table 2 to be raised and lowered via the support member 21. During the ALD process, the pressure near the substrate W can be varied by raising and lowering the mounting table 2 using the lifting mechanism 22.

[0055] Between the support member 21 and the bottom wall of the processing container 1, a bellows 23 is provided that partitions the atmosphere inside the processing container 1 from the outside air and expands and contracts in accordance with the raising and lowering movement of the mounting platform 2.

[0056] The showerhead 3 is installed on the top of the processing container 1, facing the mounting base 2, and functions as a gas discharge unit that discharges processing gas into the processing container 1 in a shower-like manner. The showerhead 3 is made of, for example, a metal material and has approximately the same diameter as the mounting base 2. A gas diffusion space 31 for diffusing gas is formed inside the showerhead 3, and a gas introduction pipe 32 is connected to the gas diffusion space 31 from above. Numerous gas discharge holes 33 are formed in the bottom wall of the showerhead 3, and the gas supplied from the gas introduction pipe 32 to the gas diffusion space 31 is discharged into the processing container 1 through the gas discharge holes 33.

[0057] The gas supply unit 4 supplies gases such as raw material gas, reaction gas, and purge gas used in ALD film formation to the processing container 1 via the showerhead 3. The raw material gas is a compound gas containing the metal component of the film to be formed, and the reaction gas is a gas that reacts with the raw material gas to form the film. The purge gas is used to purge any gas remaining in the processing container 1, and inert gases such as N2 gas or noble gases are used.

[0058] The gas supply unit 4 includes a raw material gas supply source 41a for supplying raw material gas, a reaction gas supply source 42a for supplying reaction gas, and a first purge gas supply source 43a and a second purge gas supply source 44a for supplying purge gas.

[0059] The raw material gas supply source 41a, the reaction gas supply source 42a, the first purge gas supply source 43a, and the second purge gas supply source 44a are connected to raw material gas supply piping 41b, reaction gas supply piping 42b, the first purge gas supply piping 43b, and the second purge gas supply piping 44b, respectively. The raw material gas supply piping 41b is equipped with, in order from the raw material gas supply source 41a side, an upstream valve 41c, a flow controller 41d, and a downstream valve 41e. The reaction gas supply piping 42b is equipped with, in order from the reaction gas supply source 42a side, an upstream valve 42c, a flow controller 42d, and a downstream valve 42e. The first purge gas supply piping 43b is equipped with, in order from the first purge gas supply source 43a side, an upstream valve 43c, a flow controller 43d, and a downstream valve 43e. The second purge gas supply piping 44b is equipped with, in order from the second purge gas supply source 44a side, an upstream valve 44c, a flow controller 44d, and a downstream valve 44e.

[0060] The raw material gas supply pipe 41b, the reaction gas supply pipe 42b, the first purge gas supply pipe 43b, and the second purge gas supply pipe 44b all merge into a common pipe 45, which is connected to the gas introduction pipe 32.

[0061] The first purge gas supply pipe 43b and the second purge gas supply pipe 44b are provided on the raw material gas supply pipe 41b side and the reaction gas supply pipe 42b side, respectively, and the purge gas flowing through them also functions as a carrier gas for the raw material gas and reaction gas, respectively.

[0062] The upstream valves 41c, 42c, 43c, and 44c are standard on / off valves, while the downstream valves 41e, 42e, 43e, and 44e are high-speed on / off valves for ALD. These valves are solenoid valves that are driven to open and close using solenoids. For the flow controllers 41d, 42d, 43d, and 44d, mass flow controllers are used, for example. A flow meter is also provided.

[0063] The exhaust unit 5 exhausts the inside of the processing container 1, thereby reducing the pressure inside the processing container 1. The exhaust unit 5 includes an exhaust pipe 51, an automatic pressure control valve (APC) 52, and a vacuum pump 53. The exhaust pipe 51 is connected to the exhaust port 1a. The automatic pressure control valve (APC) 52 and the vacuum pump 53 are interposed in the exhaust pipe 51. As the automatic pressure control valve (APC) 52, a valve that controls the conductance in the exhaust pipe 51 by adjusting the degree of opening can be used. The degree of opening of the pressure control valve (APC) 52 is controlled so that the pressure value of the pressure sensor 25 that detects the pressure inside the processing container 1 becomes a desired value.

[0064] In the substrate processing unit 700, the following processes are executed under the control of the control device 800, which will be described later.

[0065] First, the substrate W is brought into the processing container 1 and placed on the mounting table 2, the inside of the processing container 1 is maintained in a predetermined reduced pressure state, and the temperature of the mounting table 2 is controlled to a set temperature by a heater. In this state, purge gas is supplied from the gas supply unit 4 to the processing container 1 via the shower head 3 to purge the inside of the processing container 1.

[0066] Subsequently, the high-speed on / off valves 41e to 44e for ALD are opened and closed at high speed to repeatedly supply the raw material gas to the processing container 1, purge the residual gas in the processing container 1, supply the reaction gas to the processing container 1, and purge the residual gas in the processing container 1 at high speed. This performs an ALD process in which the adsorption of the raw material gas onto the substrate W and the formation of a film by the reaction between the raw material gas and the reaction gas are repeated, and a film of the set thickness is formed on the substrate W.

[0067] During this ALD process, at each step, high-speed pressure control is performed by an automatic pressure control valve (APC) 52, and the mounting platform 2 is raised and lowered at high speed by a lifting mechanism 22.

[0068] Next, the control device 800 will be described in detail. Figure 6 is a block diagram showing the schematic configuration of the overall control system, including the control device of the substrate processing apparatus shown in Figure 5.

[0069] The control device 800 controls each component of the substrate processing unit 700 and causes the substrate processing device 600 to perform processing. The control device 800 is configured as part of the overall control system 1000, which controls the entire substrate processing system including the substrate processing device 600, and has the wireless communication system 100 described above.

[0070] As shown in Figure 6, the overall control system 1000 includes an EC (Equipment Controller) 1100, which is a central unit that controls the entire substrate processing system, and a plurality of MCs (Module Controllers) 1200 located below it, which control each device (module) that constitutes the substrate processing system.

[0071] The EC1100 functions as a common higher-level control unit that controls multiple devices in the substrate processing system, and the substrate processing device 600 is one of these multiple devices (modules). Other devices besides the substrate processing device 600 include, for example, a load lock chamber and a loader unit. Multiple MC1200s are provided to correspond to multiple devices (modules), but Figure 6 shows only the MC1200 of the substrate processing device 600, and the others are omitted.

[0072] The control device 800 comprises an EC1100, an MC1200 corresponding to the substrate processing device 600, and a plurality of I / O modules 413 located below it. Each of the plurality of I / O modules 413 is equipped with a plurality of I / O boards 415, and each I / O board 415 is connected to an end device 701, which is a high-speed control device for processing within the substrate processing device 700. The end device 701 is a collective term for the high-speed on / off valves 41e to 44e in the gas supply section 4, flow controllers 41d to 44d, the automatic pressure control valve (APC) 52 in the exhaust section 5, the lifting mechanism 22, and sensors such as the pressure gauge 25.

[0073] The EC1100 includes a CPU (Central Processing Unit) 503, RAM 505 as volatile memory, and a hard disk drive 507 as storage. The EC1100 and each MC1200 are connected by a network 513. The network 513 includes a switching hub (HUB) 515. This switching hub 515 switches the MC1200 to which the EC1100 is connected in response to a control signal from the EC1100.

[0074] Furthermore, the EC1100 is connected via network 901 to host computer 903, which acts as an MES (Manufacturing Execution System) that manages the entire manufacturing process of the factory where the circuit board processing system is installed.

[0075] The EC1100 is also connected to a user interface 511. The user interface 511 includes a keyboard for process managers to input commands and perform other operations to manage the board processing system, a display that visualizes and shows the operating status of the board processing system, and mechanical switches.

[0076] The EC1100 is designed to record information onto a computer-readable storage medium 517 and to read information from the storage medium 517.

[0077] In the EC1100, the CPU 503 reads a program containing the processing recipe for the board W specified by the user or others via the user interface 511 from the hard disk drive 507 or storage medium 517. The EC1100 is then configured to send the program containing the processing recipe to multiple MC1200 units. As described above, one of the multiple MC1200 units corresponds to the control unit 800 of the board processing unit 600.

[0078] The MC1200, included in the control device 800 and corresponding to the substrate processing device 600, has a CPU 403, a volatile memory section 405 such as RAM, a non-volatile memory section 407 as an I / O information storage section, and an I / O control section 409.

[0079] The non-volatile memory section 407 stores various history information from the substrate processing device 600. The non-volatile memory section 407 also functions as an I / O information storage unit, and is configured to write and store various I / O information exchanged between the MC1200 and the multiple end devices 701 provided in the substrate processing unit 700 as needed, as will be described later.

[0080] The I / O control unit 409 of the MC1200 sends various control signals to the I / O board 415 of the I / O module 413 and receives signals such as status information related to each end device 701 from the I / O board 415.

[0081] Control of each end device 701 by the MC1200 is performed via the I / O board 415. The I / O board 415 transmits control signals to each end device 701 and input signals from each end device 701. The I / O board 415 and each end device 701 are connected by digital / analog signals.

[0082] A wireless communication system 100 is provided between the MC1200 and the I / O board 415. As described above, the wireless communication system 100 has a first wireless communication device 200 and a plurality of second wireless communication devices 300, with the MC1200 corresponding to the first device 400 and the I / O board 415 to which the end device 701 is connected corresponding to the second device 500. In other words, the wireless communication system 100 communicates control signals as data between the MC1200, which is a higher-level control unit, and the I / O board 415, which is a lower-level control unit.

[0083] In Figure 6, the MC1200 and multiple I / O boards 415 of one I / O module 413 are shown being wirelessly connected via the wireless communication system 100. However, multiple wireless communication systems 100 may be provided to correspond to multiple I / O modules 413. In that case, multiple channels can be provided on the MC1200, and the first device 200 of the wireless communication system 100 can be connected to each channel.

[0084] The input / output information managed by the I / O board 415 includes digital input information DI, digital output information DO, and analog input information AI. DI relates to the digital information input from each lower-level end device 701 to the upper-level MC1200. DO relates to the digital information output from the upper-level MC1200 to each lower-level end device 701. AI relates to the analog information input from each end device 701 to the MC1200.

[0085] DI and AI contain information about the status of each end device 701, for example. DO contains commands for setting values ​​related to process conditions for each end device, for example. In other words, DI and AI are sensors such as pressure gauges, flow sensors, and temperature sensors that perform monitoring and processing of the equipment, while DO is an operating system such as high-speed on / off valves, lifting mechanisms, and automatic pressure control valves (APCs) that operate the equipment.

[0086] DI, DO, and AI are each assigned I / O addresses corresponding to their respective contents. Each I / O address contains, for example, 16 bits (0-15) of digital or analog information. Analog information is represented, for example, by a hexadecimal number from 0 to FFF. Each I / O address is also assigned an address number. Furthermore, the I / O board 415 is assigned a node number starting from the number 1. Multiple channels are also assigned numbers. Therefore, the I / O addresses of DI, DO, and AI can be identified using three parameters: the channel number, the node number, and the I / O address number.

[0087] Next, the control operation of the control device 800 in the substrate processing apparatus 600 configured as described above will be explained.

[0088] In the substrate processing apparatus 600, the ALD process described above is performed as an example of substrate processing. The ALD process is carried out by the control device 800 controlling multiple end devices 701 of the substrate processing unit 700 based on the processing recipe.

[0089] First, in the control device 800 with the configuration shown in Figure 6, a processing recipe for processing the substrate W is transmitted from the EC1100 to the MC1200, which corresponds to the substrate processing device 600. Then, based on this processing recipe, the MC1200 transmits periodic data for control to the I / O board 415 via the wireless communication system 100, and controls the end device 701 connected to it.

[0090] Conventionally, substrate processing equipment such as ALD film deposition systems are equipped with numerous end devices such as solenoid valves and pressure gauges. To control these end devices, numerous signal cables are wired from the higher-level control unit, the MC1200, via the I / O module 413 and I / O board 415. As a result, a large amount of space is required for the signal cables, making it difficult to miniaturize the equipment.

[0091] In contrast, in this embodiment, a wireless communication system 100 is provided between the MC1200 of the substrate processing apparatus 600 and a plurality of I / O boards 415, and wireless communication is performed, thereby reducing the number of signal cables and enabling miniaturization of the apparatus.

[0092] However, when transmitting periodic data wirelessly, unlike conventional wired communication, the period will vary in transmission time due to ambient disturbances and deterioration of the communication environment, as mentioned above. If devices are connected by a wired communication interface or I / O cable, synchronization can be achieved by sharing a synchronization signal, so this problem does not occur. However, since wireless communication does not involve electrical signal connections, synchronization signals cannot be used.

[0093] When multiple I / O boards 415 are connected to operational end devices 701, each receiving a DO input, it is sometimes required that these end devices 701 operate synchronously. However, if there are variations in communication time as described above, it becomes difficult to achieve synchronous operation. Specifically, as shown in Figure 7(a), DO update data is sent from the MC1200 to the end devices 701 connected to each of the multiple I / O boards 415, and CRC result data is returned from the end devices 701 to the MC1200. In this case, if there are variations in communication time, variations will occur in the timing of the output of DO update data from the MC1200 to the multiple I / O boards 415, making it impossible to send the data synchronously (for example, simultaneously).

[0094] If the end device 701 acquires DI and AI, it may be required to synchronize the timing of data acquisition from the end device 701. However, if there is variation in communication time as described above, it becomes difficult to synchronize the data acquisition timing. Specifically, as shown in Figure 7(b), DI and AI update request data is sent from the MC1200 to the end devices 701 connected to each of the multiple I / O boards 415, and DI and AI data is returned from the end devices 701 to the MC1200. In this case, if there is variation in communication time, there will be variation in the output timing of the DI and AI update request data from the MC1200 to the multiple I / O boards 415, making it difficult to synchronize the data acquisition timing regardless of the control cycle (1ms, 10ms, etc.).

[0095] Therefore, using the wireless communication system 100, similar to the embodiment described above, if the time from when the first wireless device (AP) 200 transmits periodic data until the first wireless device (AP) 200 receives a response from the second wireless device (CL) 300 is less than or equal to a set value, the first wireless device (AP) 200 and the multiple second wireless devices (CL) 300 are synchronized. This makes it possible to synchronize the periodic data from the MC1200 corresponding to the first device 400 to the multiple I / O boards 415 corresponding to the multiple second devices 500, for example, simultaneously.

[0096] Furthermore, by using the wireless communication system 100 in this manner to transmit data synchronously (simultaneously) between multiple I / O boards 415 corresponding to multiple second devices 500, it is possible to suppress synchronization discrepancies between devices that may occur even in the case of wired connections.

[0097] The details are explained below. Control devices such as the MC1200 and I / O board 415 operate based on an oscillator (clock) containing a crystal resonator. Although the frequency may be changed using a PLL or similar built into the control device, the original oscillator remains the clock. In other words, the counters / timers inside the control device perform calculations based on the period of the oscillator. However, because each oscillator has individual differences, even if the nominal frequency is the same, there will always be a difference in the period produced by different oscillators. As a result, a difference in period occurs between multiple control devices, or in this example, between multiple I / O boards 415.

[0098] This period deviation is approximately ±25 ppm. For example, in the case of a 25 MHz oscillator, this corresponds to 25 MHz ± 625 Hz, i.e., in the range of 24.999375 MHz to 25.000625 MHz, and the period is in the range of 40.001 ns to 39.999 ns. If 1 second is measured in 40 ns, then 25 million counts equal exactly 1 second (1000 ms). 25 million counts in 39.999 ns is 999.975 ms, and 25 million counts in 40.001 ns is 1000.025 ms. Therefore, in the case of a 25 MHz oscillator, 1 second will vary in the range of 999.975 ms to 10000.025 ms. Although this error is small, the accumulation of these small errors results in a large synchronization deviation.

[0099] Figure 8 is a chart showing the experimental results confirming this synchronization mismatch. Here, three microcontroller boards were lined up, outputting a signal that went high with a 10ms period, and measured for approximately 8 minutes using an oscilloscope. As shown in this figure, it was confirmed that the second and third boards gradually drifted out of sync with the first board as the reference. If used for DO output or DI sampling at this timing, synchronization between the devices cannot be achieved.

[0100] In contrast, by using the wireless communication system 100 of this embodiment and employing a method to update the timer value and synchronize AP200 and CL300 when the time from when AP200 transmits periodic data until a response is received is less than or equal to a set value, synchronization errors caused by oscillator variations can also be suppressed.

[0101] Figure 9 is a chart showing experimental results confirming synchronization using a wireless communication system of one embodiment. Here, a microcontroller board corresponding to the AP and two microcontroller boards corresponding to CLs were placed side by side, and wireless communication of this embodiment was performed using multicast with a signal that goes high with a period of 10ms, and measured with an oscilloscope for about 8 minutes. As shown in this figure, no waveform shift of CL1 and CL2 relative to the AP was observed even after 8 minutes. Although the timer of CLs is delayed by less than 1ms relative to AP only during the time it takes for AP to send data to CLs, CL1 and CL2 are perfectly synchronized.

[0102] <Other applications> Although embodiments have been described above, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0103] For example, in the above embodiment, control equipment was used as an example for the first device and multiple second devices to which the wireless communication system is applied, but it is not limited to this as long as it is used for periodic data communication.

[0104] Furthermore, while the above embodiment shows an example of configuring the control unit of a substrate processing apparatus using a wireless communication system between the MC, which is a higher-level control unit, and the I / O board, which is a lower-level control unit, the apparatus is not limited to this. Moreover, although an apparatus for ALD film deposition was used as an example of a substrate processing apparatus, the substrate processing apparatus is not limited to an ALD film deposition apparatus. [Explanation of Symbols]

[0105] 1; Processing container 2; mounting platform 3; shower head 4; Gas supply department 5; Exhaust section 22; Lifting mechanism 25; pressure gauge 41e, 42e, 43e, 44e; downstream valves (high-speed opening / closing valves) 52; Automatic Pressure Control Valve (APC) 100; Wireless communication system 200; 1st radio device 201; 1st Radio Section 202; First control unit 203; First Timer 204; Transmission data generation unit 205; Received Data Monitor Unit 206; Received data determination unit 207; Flag generation unit 300;Second radio device 301; Second Communications Department 302: Second Control Unit 303; Second Timer 304; Timer value recording unit 305; Flag determination unit 306; Timer value rewriting section 400; 1st device 415; I / O board (second device) 500;Second device 600; Substrate processing equipment 700; Processing Unit 701; End devices 800; control device 1200;MC (1st device) W; substrate

Claims

1. A wireless communication system that transmits periodic data from a first device to a plurality of second devices via wireless communication, A first wireless device connected to the first device, A plurality of second wireless devices connected to each of the plurality of second devices, It has, The first wireless device comprises a first wireless unit for performing wireless communication and a first control unit for controlling the first wireless unit. The second wireless device comprises a second wireless unit for performing wireless communication and a second control unit for controlling the second wireless unit. The first control unit and the second control unit control the first wireless device and the plurality of second wireless devices to synchronize them. The first control unit creates data by adding a first timer value to the periodic data, measures the response time from when the first wireless device transmits the data to the second wireless device until it receives a response from the second wireless device to the data, determines whether the response time is less than or equal to a set value, and if it is less than or equal to the set value, transmits a flag along with the data to the second wireless device. A wireless communication system comprising: a second control unit which records the difference between the second timer value of the second wireless device and the first timer value when the second wireless device receives the data transmitted from the first wireless device; and when the second wireless device receives the data along with the flag, it rewrites the second timer value based on the difference to establish a synchronization relationship between the first wireless device and the plurality of second wireless devices.

2. The first control unit is, A first timer for measuring time in the first wireless device, A transmission data generation unit that generates data by adding the first timer value of the first timer to the periodic data from the first device, A received data monitoring unit that monitors the response time, A received data determination unit determines whether the response time monitored by the received data monitoring unit is less than or equal to a set value, A flag generation unit that generates a flag when the response time is less than or equal to a set value, It has, The second control unit is, The second wireless device includes a second timer for measuring time, A timer value recording unit records the difference between the second timer value of the second timer and the first timer value of the received data, A flag determination unit that determines the flag information of the received data, A timer value rewriting unit, upon receiving data with the aforementioned flag, rewrites the second timer value to a value obtained by subtracting the difference recorded in the timer value recording unit from the second timer value at that time, A wireless communication system according to claim 1, having the following features.

3. The wireless communication system according to claim 1 or 2, wherein the setting value is set so as to ensure desired synchronous communication between the first wireless device and the plurality of second wireless devices.

4. The wireless communication system according to claim 3, wherein the setting value is the shortest time determined based on design values ​​or actual values ​​plus a given margin.

5. The wireless communication system according to claim 3, wherein the aforementioned setting value is determined by statistical processing based on actual values.

6. The wireless communication system according to claim 5, wherein the set value is the average or central value obtained from actual values ​​by the statistical processing described above.

7. The wireless communication system according to claim 1 or 2, wherein the first device and the second device are control devices for controlling a controlled object, the first device is a higher-level control device, the plurality of second devices are lower-level control devices for controlling a controlled object, the controlled object is connected to the plurality of second devices, and the first device transmits control signals as periodic data to the plurality of second devices to control the controlled object connected to the plurality of second devices.

8. A wireless communication method for transmitting periodic data from a first device to a plurality of second devices via wireless communication, A step of preparing a wireless communication system having a first wireless device connected to the first device and a plurality of second wireless devices connected to each of the plurality of second devices, A step of synchronizing the first wireless device and the second wireless device, It has, The step of synchronizing the first wireless device and the second wireless device is: Data is created by adding the first timer value of the first wireless device to the periodic data, and the response time from when the first wireless device transmits the data to the second wireless device until a response from the second wireless device to the data is received is measured. The system determines whether the response time is less than or equal to a set value, and if it is less than or equal to the set value, it transmits the flag along with the data to the second wireless device. The difference between the second timer value of the second wireless device and the first timer value when the second wireless device receives the data transmitted from the first wireless device is recorded, When the plurality of second wireless devices receive data with the flag from the first wireless device, they rewrite the second timer value based on the difference between the first timer value and the second timer value, thereby establishing a synchronization relationship between the first wireless device and the plurality of second wireless devices. A wireless communication method having

9. The wireless communication method according to claim 8, wherein establishing a synchronization relationship between the first wireless device and the plurality of second wireless devices is such that when a second wireless device receives data with the flag, it rewrites the second timer value to a value obtained by subtracting the difference from the second timer value at that time.

10. The wireless communication method according to claim 8 or 9, wherein the setting value is set so as to ensure desired synchronous communication between the first wireless device and the plurality of second wireless devices.

11. The wireless communication method according to claim 10, wherein the setting value is obtained by adding a given margin to the shortest time determined based on design values ​​or actual values.

12. The wireless communication method according to claim 10, wherein the aforementioned setting value is determined by statistical processing based on actual values.

13. The wireless communication method according to claim 12, wherein the set value is the average or central value obtained from actual values ​​by the statistical processing described above.

14. The wireless communication method according to claim 8 or 9, wherein the first device and the second device are control devices for controlling a controlled object, the first device is a higher-level control device, the plurality of second devices are lower-level control devices for controlling a controlled object, the controlled object is connected to the plurality of second devices, and the first device transmits control signals as periodic data to the plurality of second devices to control the controlled object connected to the plurality of second devices.

15. A control device for controlling a substrate processing apparatus that performs processing on a substrate, The higher-level control unit, Multiple lower-level control units from which periodic control data is transmitted from the aforementioned higher-level control unit, A wireless communication system that transmits the periodic control data from the higher-level control unit to the plurality of lower-level control units via wireless communication, It has, The aforementioned wireless communication system is near A first wireless device connected to the aforementioned higher-level control unit, A plurality of second wireless devices connected to each of the plurality of lower-level control units, It has, The first wireless device comprises a first wireless unit for performing wireless communication and a first control unit for controlling the first wireless unit. The second wireless device comprises a second wireless unit for performing wireless communication and a second control unit for controlling the second wireless unit. The first control unit and the second control unit control the first wireless device and the plurality of second wireless devices to synchronize them. The first control unit creates data by adding a first timer value to the periodic control data, measures the response time from when the first wireless device transmits the data to the second wireless device until it receives a response from the second wireless device to the data, determines whether the response time is less than or equal to a set value, and if it is less than or equal to the set value, transmits a flag along with the data to the second wireless device. The second control unit records the difference between the second timer value of the second wireless device and the first timer value when the second wireless device receives the data transmitted from the first wireless device, and when the second wireless device receives the data along with the flag, it rewrites the second timer value based on the difference and establishes a synchronization relationship between the first wireless device and the plurality of second wireless devices.

16. The control device according to claim 15, wherein the substrate processing apparatus performs processing on a substrate using a plurality of end devices, each of the plurality of lower control units is connected to the end devices, and the periodic control data is transmitted from the upper control unit to the plurality of lower control units via the wireless communication system, thereby controlling the plurality of end devices.

17. The control device according to claim 16, wherein the lower-level control unit is an I / O board that performs input / output control of the periodic control data, and the upper-level control unit transmits digital output update data, digital input update request data, and analog input update request data as the periodic control data.

18. The control device according to any one of claims 15 to 17, wherein the substrate processing apparatus performs ALD film deposition on the substrate.

19. A control method for controlling a substrate processing apparatus that performs processing on a substrate using a control device, The control device comprises a higher-level control unit and a plurality of lower-level control units from which periodic control data is transmitted from the higher-level control unit. A step of preparing a wireless communication system having a first wireless device connected to the above-level control unit and a plurality of second wireless devices connected to each of the plurality of lower-level control units, A step of synchronizing the first wireless device and the second wireless device, A step of transmitting the periodic control data from the higher-level control unit to the lower-level control unit via the wireless communication system to control the substrate processing device, It has, The step of synchronizing the first wireless device and the second wireless device is: Data is created by adding the first timer value of the first wireless device to the periodic control data, and the response time from when the first wireless device transmits the data to the second wireless device until a response from the second wireless device to the data is received is measured. The system determines whether the response time is less than or equal to a set value, and if it is less than or equal to the set value, it transmits the flag along with the data to the second wireless device. The difference between the second timer value of the second wireless device and the first timer value when the second wireless device receives the data transmitted from the first wireless device is recorded, When the plurality of second wireless devices receive data with the flag from the first wireless device, they rewrite the second timer value based on the difference between the first timer value and the second timer value, thereby establishing a synchronization relationship between the first wireless device and the plurality of second wireless devices. A control method having

20. The substrate processing apparatus performs processing on the substrate using a plurality of end devices, and the plurality of lower-level control units are each connected to the end devices. The control method according to claim 19, wherein the step of controlling the substrate processing apparatus is to control the plurality of end devices by the periodic control data transmitted from the upper control unit to the lower control unit.

21. The control method according to claim 20, wherein the lower-level control unit is an I / O board that performs input / output control of the periodic control data, and the upper-level control unit transmits digital output update data, digital input update request data, and analog input update request data as the periodic control data.

22. The control method according to any one of claims 19 to 21, wherein the substrate processing apparatus performs ALD film deposition on the substrate.

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