Gas purging device and control method

Abstract

This invention provides a gas purging device and control method that can detect the sealing performance in a gas flow path and suppress gas leakage with a simple configuration. [Solution] The gas purging device of the present disclosure comprises: a gas nozzle for supplying gas into a container that houses a substrate and is placed on a mounting table, or for discharging the gas from the container; a drive mechanism for moving the gas nozzle between a ventilation position connected to the container and a standby position separated from the container; a detection means for detecting the value of the drive load of the drive mechanism; a measuring means disposed in a gas flow path connected to the gas nozzle for measuring at least one of the pressure, flow rate, and flow velocity of the gas flowing through the gas flow path; and a control unit for determining whether the connection between the container and the gas nozzle is normal or abnormal based on at least one of the value of the drive load and the value measured by the measuring means.

Description

Technical Field

[0005] ,

[0001] The present disclosure relates to a gas purge device and a control method.

Background Art

[0002] Substrates such as semiconductor wafers that are processed in semiconductor manufacturing equipment are accommodated in a plurality in a container called a FOUP (Front Opening Unified Pod) and transported between semiconductor manufacturing equipment. The substrate is placed and accommodated on the slot of the FOUP, and is taken in and out by a transfer arm in the semiconductor manufacturing equipment through an opening provided in the FOUP. Inside the FOUP, for example, in order to prevent deterioration of the substrate due to oxidation or moisture, or to suppress particle adhesion to the substrate, a processing gas such as a clean gas or an inert gas may be filled.

[0003] For example, Patent Document

[0005] discloses a gas purge device as a processing gas supply device, which includes a gas supply nozzle that is connected from below to a purge port at the bottom of the container in a state where the container is placed on a mounting table. In this gas purge device, when the gas supply nozzle is connected to the purge port, normal connection is detected by detecting the pressure at the time of connection with a pressure sensor provided at the tip.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] This disclosure has been made in view of the above, and aims to provide a gas purging device and control method that can detect the sealing performance in a gas flow path and suppress gas leakage with a simple configuration. [Means for solving the problem]

[0007] To solve the above problems, the first embodiment is a gas purging device comprising: a gas nozzle for supplying gas into a container that houses a substrate and is placed on a mounting table, or for discharging gas from the container; a drive mechanism for moving the gas nozzle between a ventilation position connected to the container and a standby position separated from the container; a detection means for detecting the value of the drive load of the drive mechanism; and a control unit for determining whether the connection between the container and the gas nozzle is normal or abnormal based on the value of the drive load detected by the detection means.

[0008] A second embodiment is a gas purging device according to the first embodiment, wherein the control unit determines that the connection between the container and the gas nozzle is normal when the value of the drive load is within a predetermined range.

[0009] A third embodiment is a gas purging device comprising: a gas nozzle for supplying gas into a container that houses a substrate and is placed on a mounting table, or for discharging the gas from the container; a drive mechanism for moving the gas nozzle between a ventilation position connected to the container and a standby position separated from the container; measuring means disposed in a gas flow path connected to the gas nozzle for measuring at least one of the pressure, flow rate, and flow velocity of the gas flowing through the gas flow path; and a control unit that determines whether the connection between the container and the gas nozzle is normal or abnormal based on the measured value of the measuring means.

[0010] A fourth embodiment is a gas purging device according to the third embodiment, wherein the control unit determines that the connection between the container and the gas nozzle is normal when the measured value is within a predetermined range.

[0011] A fifth aspect is a gas purging device comprising: a gas nozzle for supplying gas into a container that houses a substrate and is placed on a mounting table, or for discharging the gas from the container; a drive mechanism for moving the gas nozzle between a ventilation position connected to the container and a standby position separated from the container; a detection means for detecting the value of the drive load of the drive mechanism; a measuring means disposed in a gas flow path connected to the gas nozzle for measuring at least one of the pressure, flow rate, and flow velocity of the gas flowing through the gas flow path; and a control unit for determining whether the connection between the container and the gas nozzle is normal or abnormal based on the value of the drive load and the value measured by the measuring means.

[0012] The sixth embodiment is a gas purging device according to the fifth embodiment, wherein the control unit determines that the connection between the container and the gas nozzle is normal when the value of the drive load is within a predetermined range and the measured value is within a predetermined range.

[0013] The seventh embodiment is a gas purging device according to any one of the third to sixth embodiments, wherein the gas nozzle has a gas supply nozzle that supplies gas into the container and a gas discharge nozzle that discharges the gas from the container, and the measuring means is disposed in a gas discharge channel that connects the gas discharge nozzle to the outside from which the gas is discharged.

[0014] The eighth aspect is a gas purging device according to any one of the third to sixth aspects described above, wherein the gas nozzle has, when connected to the container, a gas supply nozzle for supplying gas into the container and a gas discharge nozzle for discharging the gas from the container, and the measuring means is disposed in a gas supply path connecting the gas supply nozzle and the gas supply source that supplies the gas.

[0015] The ninth aspect is a gas purging device according to the third or fifth aspect, wherein the gas nozzle has a gas supply nozzle for supplying gas into the container and a gas discharge nozzle for discharging the gas from the container, while connected to the container, and the measuring means has a first measuring means disposed in a gas supply channel connecting the gas supply nozzle and a gas supply source for supplying the gas, and a second measuring means disposed in a gas discharge channel connecting the gas discharge nozzle and the outside from which the gas is discharged, and the control unit determines that the connection between the container and the gas nozzle is normal when the difference or ratio between a first measured value measured by the first measuring means and a second measured value of the same type as the first measured value measured by the second measuring means is within a predetermined range.

[0016] The tenth embodiment is a gas purging device according to the sixth embodiment, wherein the control unit moves the gas nozzle to a ventilation position connected to the container by the drive mechanism, and then, before supplying the gas from the gas nozzle, the detection means detects the value of the drive load, and if the value of the drive load is within a predetermined range, the gas is supplied from the gas nozzle.

[0017] An eleventh embodiment is a control method for a gas purging device comprising: a gas nozzle for supplying gas into a container that houses a substrate and is placed on a mounting table, or for discharging the gas from the container; a drive mechanism for moving the gas nozzle between a ventilation position connected to the container and a standby position separated from the container; a detection means for detecting the value of the drive load of the drive mechanism; and a control unit for controlling the operation of each part, wherein the control unit determines that the connection between the container and the gas nozzle is normal when the value of the drive load is within a predetermined range.

[0018] A twelfth aspect is a control method for a gas purging device comprising: a gas nozzle for supplying gas into a container that houses a substrate and is placed on a mounting base, or for discharging the gas from the container; a drive mechanism for moving the gas nozzle between a ventilation position connected to the container and a standby position separated from the container; measuring means disposed in a gas flow path connected to the gas nozzle for measuring at least one of the pressure, flow rate, and flow velocity of the gas flowing through the gas flow path; and a control unit for controlling the operation of each part, wherein the control unit determines that the connection between the container and the gas nozzle is normal when the measured value of the measuring means is within a predetermined range when the gas is supplied from the gas nozzle.

[0019] A 13th aspect is a control method for a gas purge device including: a gas nozzle that accommodates a substrate and supplies gas to or discharges the gas from a container placed on a mounting table; a drive mechanism that moves the gas nozzle between a ventilation position where the gas nozzle is connected to the container and a standby position where the gas nozzle is separated from the container; detection means that detects a value of a driving load of the drive mechanism; measurement means that is disposed in a gas flow path connected to the gas nozzle and measures at least any one of a pressure, a flow rate, and a flow velocity of the gas flowing through the gas flow path; and a control unit that controls operations of each part. The control unit causes the detection means to detect the value of the driving load after moving the gas nozzle to the ventilation position where the gas nozzle is connected to the container by the drive mechanism and before supplying the gas from the gas nozzle, supplies the gas from the gas nozzle when the value of the driving load is within a predetermined range, and further determines that the connection between the container and the gas nozzle is normal when the value of the driving load is within the predetermined range and a measured value measured by the measurement means is within the predetermined range while the gas is being supplied from the gas nozzle.

Advantages of the Invention

[0020] According to the present disclosure, it is possible to provide a gas purge device and a control method that can detect a seal performance in a gas flow path with a simple configuration and suppress gas leakage.

Brief Description of the Drawings

[0021] [Figure 1] It is a schematic perspective view of a load port equipped with a gas purge device according to an embodiment of the present disclosure. [Figure 2] It is a schematic side view showing a state where a gas nozzle is connected to a FOUP placed on the load port of FIG. 1. [Figure 3] It is an enlarged view of a gas nozzle and a drive mechanism of the gas purge device of the present disclosure. [Figure 4] It is a schematic view showing a piping configuration in the gas purge device of FIG. 1. [Figure 5] It is a block diagram showing a functional configuration of a gas purge system including the gas purge device of FIG. 1. [Figure 6] A flowchart showing a control method for a gas purge device according to the first embodiment of the present disclosure. [Figure 7] A flowchart showing a control method for a gas purge device according to the second embodiment of the present disclosure. [Figure 8] A flowchart showing a control method for a gas purge device according to the third embodiment of the present disclosure. [Figure 9] A timing chart showing an example of the operation of the drive mechanism and the value of the drive load of the gas purge device of the present disclosure. [Figure 10] A timing chart showing another example of the operation of the drive mechanism and the value of the drive load of the gas purge device of the present disclosure. [Figure 11] A graph showing the value of the drive load of the drive mechanism in an abnormal state of the present disclosure.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, embodiments for carrying out the present disclosure (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an exemplification for explaining the present disclosure and is not intended to limit the present disclosure to the following content. The present disclosure can be appropriately modified and implemented within the scope of its gist. In the drawings, the same reference numerals are assigned to the same elements, and redundant descriptions are omitted. Also, the positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios in the drawings are not limited to the illustrated ratios.

[0023] FIG. 1 is a schematic perspective view of a load port 1 equipped with a gas purge device 30 according to the present embodiment. FIG. 2 is a schematic side view showing a state in which gas nozzles 41 and 43 are connected to a FOUP 10 placed on the load port 1.

[0024] As shown in Figure 1, the gas purging device 30 of this embodiment is mounted on the load port 1. The gas purging device 30 includes a gas supply nozzle 41 that houses the substrate W and supplies gas G into the FOUP 10 which is placed on the mounting base 20, and a gas discharge nozzle 43 that discharges gas G from inside the FOUP 10. As shown in Figure 2, the gas purging device 30 also includes a drive mechanism 44 that moves the gas nozzles 41 and 43 in the vertical direction (Z-axis direction), a detection unit 55 (see Figure 5) that detects the value of the drive load of the drive mechanism 44, and a control unit 50 that controls the operation of each part. The drive mechanism 44 moves the gas supply nozzle 41 and the gas discharge nozzle 43 between a position connected to the FOUP 10 and a position separated from the FOUP 10. The control unit 50 determines whether the connection between the FOUP 10 and the gas supply nozzle 41 and the gas discharge nozzle 43 is normal or abnormal.

[0025] FOUP10 is an example of a "container" relating to the technology of this disclosure. Furthermore, the gas supply nozzle 41 and the gas discharge nozzle 43 are examples of "gas nozzles" relating to the technology of this disclosure.

[0026] (Platform) As shown in Figure 1, the mounting table 20 is provided in front of the load port 1 and places the FOUP 10 containing the substrate W on it. The mounting table 20 has a dock plate 21 on which the FOUP 10 is placed. The dock plate 21 is provided with support pins 22 that support the FOUP 10 from below. The mounting table 20 has a built-in moving mechanism (not shown) that is incorporated into the base 23 and moves the dock plate 21 horizontally (in the X-axis direction in Figure 1). For example, the FOUP 10 transported by a transport device such as an OHT is placed on the dock plate 21 which is waiting on the positive X-axis side, and the dock plate 21 moves toward the plate 60 side (negative X-axis direction) and is attached to the port door 62.

[0027] Furthermore, as shown in Figure 1, a plate 60 extending vertically upward (positive Z-axis direction) is installed on the side end of the base 23 of the mounting table 20. The plate 60 constitutes a connection between the load port 1 and a substrate transport device (e.g., Equipment Front End Module (not shown)) that transfers the substrate W to a process device that performs various processing on the substrate W, and also serves as a partition between the processing area and the outside. The plate 60 has an opening 64 in the area extending upward from the base 23, and when the dock plate 21 moves toward the plate 60 and the FOUP 10 and the plate 60 come into contact, the port door 62 is opened, and the substrate W is loaded and unloaded through this opening 64. In the example in Figure 1, the mounting table 20 is further equipped with three gas supply nozzles 41 and one gas discharge nozzle 43.

[0028] (container) As shown in Figure 2, the FOUP 10 comprises a main body 11 having an opening 12 and a lid 13. The FOUP 10 can accommodate multiple substrates W by placing them on the slot with their surfaces facing upward. The FOUP 10 is provided with an opening 12, which is sealed by the lid 13. The FOUP 10, sealed by the lid 13, is transported by a transport device such as an OHT (Overhead Hoist Transport).

[0029] Furthermore, the FOUP10 is equipped with a supply nozzle port 14 into which a gas supply nozzle 41 is fitted, and a discharge nozzle port 15 into which a gas discharge nozzle 43 is fitted, at the bottom of the main body 11.

[0030] <Gas purging device> Next, the gas purging device 30 of this disclosure will be described with reference to Figures 1 to 5. Figure 3 is an enlarged view of the gas nozzles 41, 43 and drive mechanism 44 of the gas purging device 30 of this disclosure. Figure 4 is a schematic diagram showing the piping configuration in the gas purging device 30. Figure 5 is a block diagram showing the functional configuration of the gas purging system 100 including the gas purging device 30.

[0031] As shown in Figure 2, the gas purging device 30 comprises a gas supply nozzle 41, a gas discharge nozzle 43, and a drive mechanism 44. The gas purging device 30 also comprises a gas supply channel 31 connecting a gas supply source 32 and the gas supply nozzle 41, and a gas discharge channel 74 connecting the gas discharge nozzle 43 to the outside to discharge the gas inside the FOUP 10. A flow sensor 33 is provided in the gas supply channel 31, and a flow sensor 75 is provided in the gas discharge channel 74.

[0032] The gas supply channel 31 and the gas discharge channel 74 are examples of "gas channels" related to the technology of this disclosure. In addition, the flow sensors 33 and 75 are examples of "measuring means" related to the technology of this disclosure.

[0033] (Gas supply nozzle) Next, the gas supply nozzles 41 will be described with reference to Figures 1 to 3. As shown in Figure 1, the gas supply nozzles 41 are arranged in three locations on the mounting base 20 of the load port 1, for example.

[0034] As shown in Figure 3, the gas supply nozzle 41 has a base 45 attached to the drive mechanism 44 and a discharge hole 42. A sensor dog 46 is provided on the base 45. The lifting sensor 47 is installed on the lower (back side) of the dock plate 21 by screwing it in using a sensor mounting member 473. The top dead center detection sensor 471 and bottom dead center detection sensor 472 of the lifting sensor 47 installed on the lower dock plate 21 detect the position of the sensor dog 46. When the optical axis of the lifting sensor 47 is blocked by the sensor dog 46, it is detected whether the gas supply nozzle 41 or the gas discharge nozzle 43 is in the ventilation position or the standby position. As a result, the control unit 50 can grasp the position status of the gas nozzle and treat it as an abnormality if it has not reached the ventilation position. For example, a transmissive optical sensor, a reflective optical sensor, a magnetic sensor, a proximity sensor, or a limit switch can be used as the top dead center detection sensor 471 and the bottom dead center detection sensor 472.

[0035] The gas supply nozzle 41 supplies gas G into the FOUP 10 while connected to the FOUP 10. Specifically, as shown in Figure 3, the gas supply nozzle 41 has a discharge hole 42 in the center of its plan view, and the gas G supplied from the gas supply channel 31 is discharged from the discharge hole 42 by the communication between this discharge hole 42 and the gas supply channel 31.

[0036] Then, as shown in Figure 2, the gas supply nozzle 41 contacts the nozzle port 14 on the bottom surface of the FOUP 10 from below, thereby supplying gas G into the FOUP 10 from the discharge hole 42.

[0037] As shown in Figures 2 and 3, the gas supply nozzle 41 is fixed to the drive mechanism 44, and can be raised and lowered between a standby position and a ventilation position, which will be described later, by moving the drive mechanism 44 vertically up and down. The drive mechanism 44 raises and lowers the gas supply nozzle 41 vertically, thereby bringing the gas supply nozzle 41 into contact with the bottom surface of the FOUP 10. The configuration of the drive mechanism 44 will be described later.

[0038] When the FOUP 10 is not placed on the mounting base 20, the gas supply nozzle 41 is positioned in a standby position, for example, as shown in Figures 1 and 3. Here, the standby position is defined as a position where the upper end surface of the gas supply nozzle 41 is at the same height as the surface of the dock plate 21. Note that in this standby position, the upper end surface of the gas supply nozzle 41 does not necessarily have to be at the same height as the surface of the dock plate 21, but rather at a lower height than the bottom surface of the FOUP 10. Furthermore, when the FOUP 10 is placed on the mounting base 20 and gas is to be supplied into the FOUP 10, the gas supply nozzle 41 is positioned in a ventilation position, as shown in Figure 2. Here, the ventilation position is defined as a position where the upper end surface of the gas supply nozzle 41 abuts against the bottom surface of the FOUP 10, and the nozzle port 14 of the FOUP 10 and the discharge hole 42 of the gas supply nozzle 41 are in communication.

[0039] (Gas discharge nozzle) Next, the gas discharge nozzle 43 will be described with reference to Figures 1 to 3. As shown in Figure 1, the gas discharge nozzle 43 is located, for example, at one location on the mounting base 20 of the load port 1.

[0040] As shown in Figure 2, the gas purging device 30 is equipped with a gas discharge nozzle 43 and discharges the gas G inside the FOUP 10 to the outside via a gas discharge passage 74. The gas discharge nozzle 43 can have the same configuration as the gas supply nozzle 41 described with reference to Figure 3, and has a discharge hole (not shown) with the same shape as the discharge hole 42 of the gas supply nozzle 41. The discharge hole of the gas discharge nozzle 43 communicates with the nozzle port 15 on the bottom surface of the FOUP 10, thereby discharging the gas G from inside the FOUP 10 to the outside. The gas discharge nozzle 43 is fixed to a drive mechanism 44 with the same configuration as the drive mechanism 44 of the gas supply nozzle 41, and moves up and down between a ventilation position connected to the FOUP 10 and a standby position separated from the FOUP 10. In this embodiment, the gas discharge nozzle 43 is moved up and down together with the gas supply nozzle 41 by the drive mechanism 44. However, it is not limited to this, and the gas discharge nozzle 43 may be fixed to a separate lifting mechanism (not shown) from the gas supply nozzle 41.

[0041] (Drive mechanism) The drive mechanism 44 is electrically connected to the control unit 50 and, in response to commands from the control unit 50, moves the gas supply nozzle 41 and the gas discharge nozzle 43 between a ventilation position connected to the FOUP 10 and a standby position separated from the FOUP 10. As shown in Figure 2, the drive mechanism 44 is positioned below the mounting base 20 and raises or lowers the gas supply nozzle 41 and the gas discharge nozzle 43.

[0042] The drive mechanism 44 is specifically, for example, an air cylinder, an electric cylinder, an electromagnetic actuator, a ball screw drive mechanism, a linear actuator, or a combination thereof. After the FOUP 10 is placed on the mounting base 20, the drive mechanism 44 raises the gas supply nozzle 41 and the gas discharge nozzle 43 and presses them against the nozzle ports 14 and 15, maintains the contact pressure during gas supply, and lowers and retracts them after the gas supply G is finished.

[0043] As shown in Figure 3, the drive mechanism 44 consists of a main body 441, a mounting part 442 for attaching the gas supply nozzle 41 and the gas discharge nozzle 43, and a movable part 443.

[0044] The main body 441 contains the power source that operates the movable part 443. For example, if the drive mechanism 44 is an air cylinder, the drive mechanism 44 uses compressed air as its power source and moves the gas supply nozzle 41 and the gas discharge nozzle 43 vertically by applying the pressure of the compressed air to the piston inside the cylinder. In this case, the value of the drive load of the drive mechanism 44 is a value related to air pressure, such as the head chamber pressure, rod chamber pressure, supply pressure, or differential pressure.

[0045] If the drive mechanism 44 is an electric actuator, the drive mechanism 44 uses the power supplied to the motor as its power source and converts the torque generated in accordance with the drive current flowing through the motor into a linear thrust via a ball screw or linear drive mechanism, thereby moving the gas supply nozzle 41 and the gas discharge nozzle 43 in the vertical direction. In this case, the value of the drive load of the drive mechanism 44 is the drive current, the torque command value, or the torque limit reached signal.

[0046] As an example, the travel distance of the drive mechanism 44 can be set to approximately 5 mm, and the reference pressing force per gas nozzle 41 or 43 can be set to a range of 17 N to 34 N. If the drive mechanism 44 is air-powered, the operating pressure can be set to a range of 0.05 MPa to 1.0 MPa, and a configuration can be adopted in which a pressing force of approximately 34 N is generated by a supply pressure of 0.3 MPa, for example. If the drive mechanism 44 is electric, a configuration can be adopted in which the pressing force is continuously adjusted by setting the current.

[0047] (Detection means) The detection means is a means for detecting the value of the drive load of the drive mechanism 44. In this embodiment, the detection unit 55 (see Figure 5) of the control unit 50 functions as the detection means, and the detection unit 55 detects the drive current, drive voltage, drive pressure, torque command value, torque limit reached signal, or the corresponding physical quantity in the drive mechanism 44 as the value of the drive load. In an electric drive mechanism 44, the value of the drive load is, for example, the drive current flowing to the motor, and when the gas supply nozzle 41 or gas discharge nozzle 43 is connected to the nozzle ports 14 and 15 and receives a reaction force, it is detected as the current value corresponding to the pressing state. In an air-operated drive mechanism 44, the value of the drive load is, for example, the head chamber air pressure or the supply pressure of the lifting air, and is detected as the pressure required to raise the nozzle.

[0048] (Gas supply channel) As shown in Figure 4, the gas supply channel 31 has a gas supply nozzle 41 attached to one end and is connected to a gas supply source 32 at the other end, and supplies gas G from the gas supply source 32 to the gas supply nozzle 41. The gas supply source 32 is connected, for example, to piping connected to an external gas supply facility (not shown) for supplying gas, via a connecting joint.

[0049] The gas supply source 32 can be any gas that supplies an inert gas such as N2 or a clean gas, and the type of gas is determined by the film formed on the substrate W housed in the FOUP 10 and the content of the substrate processing. As shown in Figure 4, the N2 gas from the gas supply source 32 is supplied to the gas supply nozzle 41 via a plurality of piping components.

[0050] In this embodiment, the gas supply channel 31 has, in order from upstream, a pressure monitor 72, an upstream valve 36, a mass flow controller 35, a downstream valve 37, and a flow sensor 33. In this embodiment, the gas supply channel 31 branches downstream of the flow sensor 33 and connects to three gas supply nozzles 41, respectively. In each gas supply channel 31 after branching, in order from upstream, a speed controller 38, a gas filter 39, a flow velocity sensor 73, and a flow sensor 70 are arranged. The pressure monitor 72, flow sensors 33 and 70, and flow velocity sensor 73 are examples of "measurement means" related to the technology of this disclosure. The measurement means will be described later.

[0051] The mass flow controller 35 controls the flow rate of gas G flowing through the gas supply channel 31 so that it reaches a set flow rate. The mass flow controller 35 can be any known device; any commercially available device that controls the flow rate of gas is acceptable. As shown in Figure 4, the mass flow controller 35 is positioned between the upstream valve 36 and the downstream valve 37 and controls the flow rate of the entire gas purging device 30.

[0052] According to an embodiment of the present disclosure, an upstream valve 36 and a downstream valve 37 are provided in the gas supply passage 31 with a mass flow controller 35 in between. When each valve is opened, gas G supplied from the gas supply source 32 is discharged from the gas supply nozzle 41. The upstream valve 36 and the downstream valve 37 may be of the same type, or a combination of an air valve and a solenoid valve may be used. In this case, the air valve is connected to an air supply source (not shown) via an air supply passage (not shown), and is in an open state when air is supplied and in a closed state when air is not supplied. The supply of air to the air valve is controlled by a solenoid valve provided in the air supply passage. Air is supplied when current flows through the solenoid valve, and no air is supplied when the current to the solenoid valve is interrupted.

[0053] The speed controller 38 adjusts the gas flow rate in each branch line to ensure that the gas flow rate discharged from each gas supply nozzle 41 is uniform. The gas filter 39 is used to improve the cleanliness of the gas discharged into the FOUP 10.

[0054] (Gas discharge channel) As shown in Figure 4, the gas purging device 30 is equipped with a gas discharge channel 74 for discharging gas from within the FOUP 10. The gas discharge channel 74 is connected to a gas discharge nozzle 43 provided on the mounting base 20. In Figure 2, the gas G supplied into the FOUP 10 from the gas supply nozzle 41 is discharged from the gas discharge nozzle 43. The gas G discharged from the gas discharge nozzle 43 is then discharged to the outside of the device through the gas discharge channel 74 connected to the gas discharge nozzle 43.

[0055] As shown in Figure 4, a flow sensor 75 is positioned near the gas discharge nozzle 43 in the gas discharge channel 74 to detect the flow rate of gas G flowing into the gas discharge channel 74. This flow sensor 75 is an example of a "measurement means" related to the technology of this disclosure.

[0056] (Method of measurement) The gas purging device 30 includes measuring means arranged in the gas supply channel 31 or gas discharge channel 74 connected to the gas supply nozzle 41 or gas discharge nozzle 43. These measuring means measure at least one of the pressure, flow rate, and flow velocity of the gas G flowing through the gas supply channel 31 or gas discharge channel 74.

[0057] In the example shown in Figure 4, the measuring means includes a pressure monitor 72, a flow sensor 33, a flow sensor 70, a flow sensor 75, and a flow velocity sensor 73, which are provided in the gas supply passage 31 or the gas discharge passage 74. As shown in Figure 4, all of these pressure monitors 72, flow velocity sensors 73, and flow sensors 33, 70, and 75 may be provided, or only one of them may be provided, or two or more of them may be provided in any combination.

[0058] The pressure of gas G is a value representing the pressure in the gas supply channel 31 or the gas discharge channel 74, and is measured by a pressure monitor 72. An example of such a pressure monitor 72 is a semiconductor pressure monitor. The pressure monitor 72 monitors the pressure of the gas supplied from the gas supply source 32. By constantly monitoring the gas pressure, abnormalities in the upstream valve 36, mass flow controller 35, and downstream valve 37 can be detected.

[0059] The flow rate of gas G is a value representing the amount of gas G flowing through the gas supply channel 31 or the gas discharge channel 74 per unit time, and is measured by flow sensor 33, flow sensor 70, or flow sensor 75. Examples of such flow sensors 33, 70, and 75 include differential pressure flow sensors and thermal flow sensors. Flow sensor 70 monitors the flow rate of gas G flowing through the gas supply channel 31. By constantly monitoring the gas flow rate downstream of the gas supply channel 31, it is possible to detect abnormalities in the mass flow controller 35 or gas leaks.

[0060] The flow velocity of gas G is a value representing the speed of gas G flowing through the gas supply channel 31 or the gas discharge channel 74, and is measured by a flow velocity sensor 73. Examples of such a flow velocity sensor 73 include an ultrasonic flow velocity sensor, a hot-wire flow velocity sensor, or a combination thereof.

[0061] In the technology disclosed herein, the connection status between the FOUP 10 and the gas supply nozzle 41 or gas discharge nozzle 43 is detected using the measured values ​​of the measurement means described above.

[0062] When measuring means are provided in the gas supply channel 31, the measuring means may be provided in the common channel before it branches into multiple gas supply nozzles 41, such as a flow sensor 33, or in each branch channel connected to each gas supply nozzle 41, such as a flow sensor 70. When measuring means are provided in the common channel before branching, the total flow state of the gas G supplied to the multiple gas supply nozzles 41 can be grasped by a single measuring means. On the other hand, when measuring means are provided in each branch channel, the flow state corresponding to each gas supply nozzle 41 can be grasped individually.

[0063] Furthermore, the measuring means may be provided in the gas discharge channel 74 that connects the gas discharge nozzle 43 to the outside. In the example in Figure 4, a flow sensor 75 is placed in the gas discharge channel 74, but instead of the flow sensor 75, or in addition to the flow sensor 75, a pressure monitor, a flow velocity sensor, or a combination thereof may be placed. In this case, the measuring means measures the pressure, flow rate, or flow velocity of the gas G that passes through the FOUP 10 and is discharged from the gas discharge nozzle 43. In the configuration in which the measuring means is provided in the gas discharge channel 74, it is possible to detect the state in which the gas G supplied into the FOUP 10 from the gas supply nozzle 41 flows through the FOUP 10 and is then discharged from the gas discharge nozzle 43. For this reason, if there is a connection failure between the gas supply nozzle 41 and the FOUP 10, a connection failure between the gas discharge nozzle 43 and the FOUP 10, or if gas G leaks outside the FOUP 10, the measured value of the gas discharge channel 74 will fluctuate.

[0064] Furthermore, the measuring means may be provided in a position close to the gas supply nozzle 41 or the gas discharge nozzle 43. For example, a measuring means for measuring the pressure, flow rate, and flow velocity of the gas G flowing near the gas supply nozzle 41, or a combination thereof, can be provided at the position of the flow sensor 70 shown in Figure 4. Also, a measuring means for measuring the pressure, flow rate, and flow velocity of the gas G flowing near the gas discharge nozzle 43, or a combination thereof, can be provided at the position of the flow sensor 75 shown in Figure 4. In other words, the flow sensors 70 and 75 are not limited to a configuration that measures only the flow rate, but can be replaced with a pressure sensor, a flow velocity sensor, a flow sensor, or a composite sensor that integrates or combines these.

[0065] When a measuring means is provided near the gas supply nozzle 41 or the gas discharge nozzle 43, the measuring means can measure the gas flow state of the gas G at a position close to the nozzle ports 14 and 15. This allows for accurate acquisition of measurement values ​​near the gas supply nozzle 41 or the gas discharge nozzle 43. In other words, it is possible to reduce the effects of pressure loss, response delay, or flow rate fluctuations caused by flow path elements such as the gas supply source 32, mass flow controller 35, upstream valve 36, downstream valve 37, speed controller 38, and gas filter 39.

[0066] (Control Unit) Next, the control unit 50 of the gas purging device 30 of this disclosure will be described with reference to Figures 2 and 5. As shown in Figure 5, the control unit 50 is electrically connected to the upstream valve 36, the downstream valve 37, the mass flow controller 35, the drive mechanism 44, the pressure monitor 72, the flow sensor 33, the flow sensor 70, the flow sensor 75, and the flow velocity sensor 73. The control unit 50 and these components constitute a part of the gas purging system 100.

[0067] The control unit 50 determines whether the connection between the FOUP 10 and the gas nozzles 41 and 43 is normal or abnormal, based on the value of the drive load detected by the detection means, the measured value measured by the measurement means, or a combination thereof. The control unit 50 determines that the connection is normal when the value of the drive load is within a predetermined range when using the drive load value, when the measured value is within a predetermined range when using the measured value, or when both are within a predetermined range when using both.

[0068] As shown in Figure 2, the control unit 50 includes a controller 51 that receives various control programs and input data from an input device (not shown) to control the operation of each part of the gas purging device 30, and a storage unit 52 that stores various control programs, control conditions, and input data.

[0069] The controller 51 is composed of, for example, a CPU (Central Processing Unit), memory such as ROM (Read Only Memory) and RAM (Random Access Memory), and controls the operation of each part by executing a predetermined program. The CPU controls each component and performs various calculations according to the program recorded in the ROM or storage unit 52.

[0070] The storage unit 52 can consist of a storage medium such as a hard disk drive, compact disk, flash memory, flexible disk, or memory card. A control program is stored in these storage media, and the control program is installed in the control unit 50 and executed by the controller 51.

[0071] As shown in Figure 5, the control unit 50 includes, functionally, a gas supply control unit 53, a nozzle control unit 54, a detection unit 55, a measurement unit 56, and a determination unit 57.

[0072] (Gas supply control unit) The gas supply control unit 53 controls the supply operation of gas G supplied from the gas supply source 32 to the gas supply nozzle 41. Specifically, the gas supply control unit 53 controls the operation of the mass flow controller 35, the upstream valve 36, and the downstream valve 37 provided in the gas supply flow path 31 to start, continue, stop, and adjust the supply amount of gas G. If the determination unit 57 determines that the connection between the FOUP 10 and the gas supply nozzle 41 or gas discharge nozzle 43 is normal, the gas supply control unit 53 supplies gas G from the gas supply source 32 to the gas supply nozzle 41 via the gas supply flow path 31 and continues the supply. On the other hand, if the determination unit 57 determines that the connection is abnormal, for example, the gas supply control unit 53 closes the upstream valve 36 or the downstream valve 37 to stop the supply of gas G. This prevents gas G from leaking to the outside when there is a poor connection between the FOUP 10 and the gas nozzle.

[0073] (Nozzle control unit) The nozzle control unit 54 controls the drive mechanism 44 to move the gas supply nozzle 41 and the gas discharge nozzle 43 between a ventilation position connected to the FOUP 10 and a standby position separated from the FOUP 10. Specifically, after the FOUP 10 is placed on the mounting base 20, the nozzle control unit 54 operates the drive mechanism 44 to raise the gas supply nozzle 41 and the gas discharge nozzle 43 to connect them to the nozzle ports 14 and 15 of the FOUP 10. Furthermore, while gas G is being supplied, the nozzle control unit 54 controls the drive mechanism 44 to maintain the state in which the gas supply nozzle 41 and the gas discharge nozzle 43 are pressed against the nozzle ports 14 and 15. When the supply of gas G ends, or when an abnormality is detected by the determination unit 57, the nozzle control unit 54 controls the drive mechanism 44 to lower the gas supply nozzle 41 and the gas discharge nozzle 43, separating them from the FOUP 10.

[0074] If the drive mechanism 44 is an air cylinder, the nozzle control unit 54 moves the gas supply nozzle 41 and the gas discharge nozzle 43 vertically by controlling the supply and exhaust of air for lifting and lowering. If the drive mechanism 44 is an electric actuator, the nozzle control unit 54 moves the gas supply nozzle 41 and the gas discharge nozzle 43 vertically by driving, stopping, controlling the position, controlling the speed, or controlling the pressing force of the motor. Furthermore, the nozzle control unit 54 may check whether the gas supply nozzle 41 and the gas discharge nozzle 43 are in the ventilation position or the standby position based on the detection results of the lifting sensor 47 shown in Figure 3.

[0075] (Detection unit) The detection unit 55 detects the value of the drive load of the drive mechanism 44. The value of the drive load is a value that indicates the load generated when the drive mechanism 44 moves the gas supply nozzle 41 and the gas discharge nozzle 43 to the position where they are connected to the FOUP 10, or when it maintains that connected state. If the drive mechanism 44 is an electric actuator, the detection unit 55 detects, for example, the drive current flowing to the motor, the torque command value, the torque limit reached signal, or a value corresponding thereto as the value of the drive load. If the drive mechanism 44 is an air cylinder, the detection unit 55 detects, for example, the supply pressure of the lifting air, the head chamber pressure, the rod chamber pressure, the differential pressure, or a value corresponding thereto as the value of the drive load.

[0076] The drive load value detected by the detection unit 55 serves as an indicator of whether the gas supply nozzle 41 or the gas discharge nozzle 43 is properly pressed against the nozzle ports 14 and 15. For example, if the gas supply nozzle 41 or the gas discharge nozzle 43 is properly connected to the nozzle ports 14 and 15, the drive load value will be within a predetermined range stored in the storage unit 52. On the other hand, if the gas nozzle has not reached the nozzle ports 14 and 15, if the FOUP 10 is lifted, if a gap occurs between the gas nozzle and the nozzle ports 14 and 15, or if the gas nozzle is pressed with excessive force, the drive load value may be outside the predetermined range. Therefore, the mechanical connection state can be determined by using the detection result of the detection unit 55.

[0077] The values ​​of the drive load will be described in more detail with reference to Figures 9 to 11. Figure 9 is a timing chart showing an example of the operation and drive load values ​​of the drive mechanism 44 of the gas purging device 30 of this disclosure. Figure 10 is a timing chart showing another example of the operation and drive load values ​​of the drive mechanism 44 of the gas purging device 30 of this disclosure. Figure 11 is a graph showing the drive load values ​​of the drive mechanism 44 in an abnormal condition of this disclosure.

[0078] Figure 9 schematically shows the timing chart for the normal operation of the air-operated system. As shown in Figure 9, when the supply command is turned on, the gas supply nozzle 41 rises from a standby position away from the FOUP 10 to a ventilation position connected to the nozzle port 14. At this time, when the gas supply nozzle 41 rises from the standby position to the ventilation position, the bottom dead center detection sensor 472 enters a non-detection state where it does not detect the sensor dog 46, and the top dead center detection sensor 471 enters a detection state where it detects the sensor dog 46. The gas supply nozzle 41 comes into contact with the nozzle port 14, and the driving air pressure increases to maintain the pressure during contact. As an example, 0.3 MPa is continuously supplied as the head chamber pressure during contact, and the piston is pressed against the stroke end. The coil current of the solenoid valve shows an inrush current of approximately 150 mA at the moment of startup, and is continuously energized with a holding current of approximately 30 mA in steady state. The pressing force is determined by the air pressure and the pressure-receiving area, and can be set to, for example, approximately 34 N. During descent, the solenoid valve is turned off, the supply pressure is exhausted, and the gas nozzle descends due to the pressure on the rod side or the return mechanism.

[0079] Figure 10 schematically shows the timing chart for the normal operation of the electric system. As shown in Figure 10, when the start command is turned on, the gas supply nozzle 41 rises from a standby position away from the FOUP 10 to a ventilation position connected to the nozzle port 14. At this time, when the gas supply nozzle 41 rises from the standby position to the ventilation position, the bottom dead center detection sensor 472 enters a non-detection state where it does not detect the sensor dog 46, and the top dead center detection sensor 471 enters a detection state where it detects the sensor dog 46. The drive current of the drive mechanism 44 changes according to each stage of rising, pressing / purging execution, and lowering. As an example, the holding current during standby is approximately 0.1A, and a momentary peak of approximately 2.0A occurs at startup. During pressing, a drive current of approximately 0.24A is continuously supplied, and a pressing force of approximately 34N is obtained. The torque limit reached signal turns on during pressing and switches off when the nozzle moves away from the FOUP 10. In the electric system, the pressing force can be adjusted by setting the current, and even when using an actuator with a maximum pressing force of 400N, it can be used with a pressing force limited to one suitable for FOUP10.

[0080] As described above, the raising and lowering state of the gas nozzles 41 and 43, and the connection status between the FOUP 10 and the gas nozzles 41 and 43 can be detected based on the values ​​of the drive load, such as the drive air pressure and drive current.

[0081] Figure 11 schematically shows an example of the drive current of the electric system when the FOUP 10 separates from the gas nozzle during gas purging. As shown in Figure 11, while the FOUP 10 is in contact with the gas nozzle, the drive current is maintained at the level of the contact current. When the FOUP 10 floats or separates and the reaction force acting on the gas nozzle disappears, the required torque decreases in the feedback control, and the drive current drops from the contact current level to the holding current level. For example, the drive current drops from approximately 0.24A to approximately 0.1A, and at the same time, the torque limit reached signal is turned off. As a result, the control unit 50 can quickly detect separation or connection abnormalities between the FOUP 10 and the gas nozzle based on the value of the electric drive load, without the need for an additional contact pressure sensor.

[0082] (Measurement Department) The measuring unit 56 acquires measured values ​​of the gas G flowing through the gas passages from measuring means arranged in the gas passages 31 and 74 connected to the gas nozzles 41 and 43. The measuring means are means for measuring at least one of the pressure, flow rate, and flow velocity of the gas G, and in the example shown in Figure 4, these are a pressure monitor 72, a flow velocity sensor 73, and flow rate sensors 33, 70, and 75. The measuring unit 56 acquires the pressure, flow rate, or flow velocity in the gas supply passage 31, or the pressure, flow rate, or flow velocity in the gas discharge passage 74, from these measuring means. The measuring means may be all of the pressure monitor 72, flow velocity sensor 73, and flow rate sensors 33, 70, and 75, or one of them, or any combination of two or more.

[0083] The measuring unit 56 acquires measured values ​​when gas G is supplied from the gas supply nozzle 41. When the gas supply nozzle 41 and the gas discharge nozzle 43 are properly connected to the FOUP 10, gas G flows through the gas supply passage 31, gas supply nozzle 41, inside the FOUP 10, the gas discharge nozzle 43, and the gas discharge passage 74 in a predetermined flow state. At this time, the pressure, flow rate, or flow velocity acquired by the measuring unit 56 will be within a predetermined range. On the other hand, if there is an abnormality in the connection between the gas supply nozzle 41 or the gas discharge nozzle 43 and the FOUP 10, the measured values ​​may fall outside the predetermined range due to gas G leakage, insufficient supply, insufficient discharge, or changes in flow resistance.

[0084] Furthermore, the measurement unit 56 may acquire measured values ​​from measuring means positioned near the gas supply nozzle 41 or the gas discharge nozzle 43. For example, measuring means for measuring pressure, flow rate, and flow velocity, or a combination thereof, can be provided at the location of the flow sensor 70 close to the gas supply nozzle 41, or at the location of the flow sensor 75 close to the gas discharge nozzle 43. In this case, the measurement unit 56 can acquire measured values ​​at a location close to the nozzle ports 14 and 15, making it possible to determine the connection status between the gas supply nozzle 41 or the gas discharge nozzle 43 and the FOUP 10 with greater accuracy.

[0085] (Judgment Department) The determination unit 57 determines whether the connection between the FOUP 10 and the gas nozzle is normal or abnormal, based on at least one of the drive load value detected by the detection unit 55 and the measured value obtained by the measurement unit 56.

[0086] When the determination unit 57 uses the drive load value for determination, it compares a predetermined range of drive load values ​​stored in the storage unit 52 with the drive load value detected by the detection unit 55. The determination unit 57 determines that the connection between the FOUP 10 and the gas nozzle is normal if the drive load value is within the predetermined range, and determines that the connection between the FOUP 10 and the gas nozzle is abnormal if the drive load value is outside the predetermined range.

[0087] Furthermore, when the determination unit 57 uses the measured values ​​obtained by the measurement unit 56, it compares a predetermined range of measured values ​​stored in the storage unit 52 with the measured values ​​of pressure, flow rate, or flow velocity obtained by the measurement unit 56. The determination unit 57 determines that the connection between the FOUP 10 and the gas nozzles 41 and 43 is normal if the measured value when gas G is supplied from the gas supply nozzle 41 is within the predetermined range, and determines that the connection between the FOUP 10 and the gas nozzles is abnormal if the measured value is outside the predetermined range.

[0088] The predetermined range includes a lower limit and an upper limit. For example, the lower limit is set as a value that can detect insufficient connection, gas leakage, insufficient supply, or insufficient discharge, while the upper limit is set as a value that can detect excessive supply, poor discharge, flow path blockage, or excessive pressure.

[0089] The determination unit 57 may make a determination using both the drive load value and the measured value. In this case, the determination unit 57 determines that the connection between the FOUP 10 and the gas nozzles 41 and 43 is normal if both the drive load value and the measured value are within a predetermined range. On the other hand, if either the drive load value or the measured value is outside the predetermined range, the determination unit 57 can determine that the connection between the FOUP 10 and the gas nozzles 41 and 43 is abnormal.

[0090] When making a determination using the drive load value and the measured value in this way, both the mechanical contact state and the sealing performance in the gas flow path can be considered. For example, the drive load value can be used to determine whether the gas supply nozzle 41 or the gas discharge nozzle 43 is pressed against the nozzle ports 14 and 15. The measured value can be used to determine whether the gas G is flowing properly through the FOUP 10 and whether the gas G is leaking out of the FOUP 10. That is, even if the drive load value is within a predetermined range, if the measured value is outside the predetermined range, the determination unit 57 can determine that there is an abnormal connection where mechanical contact is established but the sealing performance is insufficient. Also, even if the measured value is within a predetermined range, if the drive load value is outside the predetermined range, it can be determined that there is excessive pressure, insufficient contact, or a drive mechanism abnormality. Therefore, it is possible to detect a state where the gas nozzle is mechanically pressed but the sealing performance is insufficient, or a pressure abnormality that is difficult to determine from the measured value of the gas flow path alone.

[0091] Furthermore, the determination unit 57 may determine the connection status between the FOUP 10 and the gas nozzle based on the difference between the measured value of the first measuring means installed in the gas supply passage 31 and the measured value of the second measuring means installed in the gas discharge passage 74. In the example in Figure 4, the first measuring means includes a pressure monitor 72, a flow velocity sensor 73, and flow rate sensors 33 and 70, and the second measuring means includes a flow rate sensor 75. The first and second measuring means may measure the same type of measured value, for example, both pressure, both flow rate, or both flow velocity. In this case, the determination unit 57 calculates the difference or ratio between the first measured value and the second measured value. The determination unit 57 determines that the connection between the FOUP 10 and the gas nozzle is normal if the difference or ratio is within a predetermined range. By using the difference, the connection status can be determined not only based on the absolute value of the supply side or the discharge side, but also based on the relative relationship between the supply side and the discharge side, thus enabling stable abnormality detection in response to fluctuations in gas supply conditions. The determination unit 57 may also perform the determination using the ratio of the measured value of the first measuring means and the measured value of the second measuring means, instead of the difference in the measured values.

[0092] As described above, the gas supply control unit 53 controls the supply operation of gas G, the nozzle control unit 54 controls the movement of the gas supply nozzle 41 and the gas discharge nozzle 43, the detection unit 55 detects the drive load value of the drive mechanism 44, the measurement unit 56 acquires the pressure, flow rate, or flow velocity of gas G in the gas flow path, and the determination unit 57 determines the connection status between the FOUP 10 and the gas nozzle based on these values. Therefore, the gas purging device 30 can check the mechanical connection status of the gas nozzle and the flow status or seal status in the gas flow path before or during the supply of gas G, and can suppress gas G leakage due to poor connection.

[0093] <Control Method> The operation of the gas purging device 30 with the configuration described above will be explained in detail with reference to Figures 6 to 8. Figure 6 is a flowchart showing the control method of the gas purging device 30 according to the first embodiment of this disclosure.

[0094] <First Embodiment> In the example shown in Figure 1, an OHT (not shown) transports the FOUP 10 to the load port 1, and the FOUP 10 is placed on the dock plate 21. At this time, the gas supply nozzle 41 is waiting in a standby position where the upper end surface of the nozzle and the surface of the dock plate 21 are at the same height. The FOUP 10 is then handed over to the support pins 22 of the dock plate 21.

[0095] In the control method S1 of the first embodiment, when the control unit 50 receives a gas supply start command from a higher-level control device or operation input, it reads the operating conditions stored in the storage unit 52 (step S101). The operating conditions include the lifting speed of the drive mechanism 44, the pressing force, a predetermined range of the drive load, the flow rate setting of the gas G supplied from the gas supply source 32, the control value of the mass flow controller 35, and the opening and closing conditions of the upstream valve 36 and the downstream valve 37. After confirming that the FOUP 10 is placed on the mounting base 20 and positioned by the support pins 22, the control unit 50 prepares the gas nozzles 41 and 43 to lift.

[0096] The nozzle control unit 54 operates the drive mechanism 44 to move the gas supply nozzle 41 and the gas discharge nozzle 43 from the standby position to the ventilation position (step S102). During this upward movement, the top dead center detection sensor 471 of the lifting sensor 47 detects the position of the sensor dog 46 and outputs the position state to the control unit 50. The gas supply nozzle 41 approaches the nozzle port 14 of the FOUP 10 from below, and the gas discharge nozzle 43 approaches the nozzle port 15 of the FOUP 10 from below.

[0097] Next, the gas supply control unit 53 opens the upstream valve 36 and the downstream valve 37, operates the mass flow controller 35 at the set flow rate, and starts supplying gas G from the gas supply source 32 to the gas supply nozzle 41 through the gas supply channel 31 (step S103). The gas G is introduced into the FOUP 10, replacing the atmosphere inside the FOUP 10 and suppressing oxidation or particle contamination of the substrate W inside the FOUP 10. The gas discharge nozzle 43 discharges the gas G inside the FOUP 10 to the gas discharge channel 74, increasing the purging efficiency while suppressing the pressure rise inside the FOUP 10.

[0098] Next, the detection unit 55 detects the value of the drive load, and the measurement unit 56 measures the pressure, flow rate, or flow velocity in the gas flow paths 31 and 74 (step S104).

[0099] If the drive mechanism 44 is electrically operated, the detection unit 55 acquires the drive current while the gas nozzles 41 and 43 are rising, the current change when they make contact, and the current while they are being pressed. If the drive mechanism 44 is air-operated, the detection unit 55 acquires the supply pressure of the lifting / lowering air or the drive air pressure.

[0100] The measuring unit 56 acquires measured values ​​when gas G is supplied from the gas supply nozzle 41. The measured values ​​are the pressure of gas G in the gas supply channel 31, the flow rate of gas G in the gas supply channel 31, the flow rate of gas G in each branch channel, the flow velocity of gas G in the gas supply channel 31, or the flow rate of gas G in the gas discharge channel 74. If the gas supply nozzle 41 or the gas discharge nozzle 43 is properly connected to the nozzle ports 14 and 15 and sealing is ensured, gas G flows through the gas channels 31 and 74 into the FOUP 10, and the measured values ​​are within the predetermined range. If there is a connection problem, gas G will leak out of the FOUP 10, there will be insufficient gas G passing through the FOUP 10, the discharge flow rate will decrease, or there will be a change in the supply pressure, causing the measured values ​​to deviate from the predetermined range.

[0101] While supplying gas G, the determination unit 57 compares the acquired drive load value and the measured value with their respective predetermined ranges and determines whether the drive load value and the measured value are within the predetermined range (step S105). In this example, the determination unit 57 determines whether the drive current is within the predetermined range as the drive load value. The predetermined range is set according to the distance between the FOUP 10 and the gas nozzles 41 and 43, the type of gas G, the set flow rate, the capacity of the FOUP 10, the number of gas supply nozzles 41, the number of gas discharge nozzles 43, the pressure loss of the gas filter 39, and the setting value of the mass flow controller 35. If both the drive load value and the measured value are above the lower limit and below the upper limit of the predetermined range, the determination unit 57 determines that the connection between the FOUP 10 and the gas nozzles is normal. If either the drive load value or the measured value is below the lower limit of a predetermined range or exceeds the upper limit of a predetermined range, the determination unit 57 determines that the connection between the FOUP 10 and the gas nozzle is abnormal, and the gas supply control unit 53 closes the upstream valve 36 or the downstream valve 37 to stop the supply of gas G (End).

[0102] If the determination unit 57 determines that the connection is normal, the gas supply control unit 53 continues to supply gas G (step S106). During the supply of gas G, the measurement unit 56 periodically or continuously acquires pressure, flow rate, or flow velocity. This allows the determination unit 57 to detect abnormalities not only at the start of gas G supply, but also when the FOUP 10 floats up during gas G supply, when the gas supply nozzle 41 or gas discharge nozzle 43 moves away from the nozzle ports 14 and 15, when the gas filter 39 becomes clogged, or when the supply status of the gas supply source 32 changes.

[0103] Furthermore, the drive load value is continuously acquired while gas G is being supplied. The detection unit 55 monitors the drive load value even while gas G is being supplied. For example, in an electric actuator, if the FOUP 10 floats up and the contact reaction force disappears, the drive current decreases from a pressing current to a holding current, so the determination unit 57 can detect separation or connection abnormality.

[0104] In the first embodiment described above, the determination unit 57 determined the connection state between the FOUP 10 and the gas nozzles 41 and 43 based on the drive load value acquired by the detection unit 55 and the measured value acquired by the measurement unit 56, but the disclosure is not limited thereto. The determination unit 57 may determine the connection state between the FOUP 10 and the gas nozzles 41 and 43 based only on the drive load value acquired by the detection unit 55. Alternatively, the determination unit 57 may determine the connection state between the FOUP 10 and the gas nozzles 41 and 43 based only on the measured value acquired by the measurement unit 56. In either case, the connection state between the FOUP 10 and the gas nozzles 41 and 43 can be detected accurately with a simple configuration.

[0105] <Second Embodiment> Next, a second embodiment of the technology of this disclosure will be described with reference to Figure 7. Note that the same reference numerals are used for the components described above, and their descriptions are omitted. Figure 7 shows a control flow S2 that determines the connection state based on the difference between the measured value on the gas supply channel 31 and the measured value on the gas discharge channel 74.

[0106] As shown in Figure 7, the control unit 50 receives a gas supply start command, raises the gas supply nozzle 41 and the gas discharge nozzle 43, and starts supplying gas G. Subsequently, the measuring unit 56 of the control unit 50 causes the first measuring means to measure the gas supply pressure Ps and the second measuring means to measure the gas exhaust pressure Pe (step S204).

[0107] The determination unit 57 uses the measured values ​​obtained in step S204 to calculate the differential pressure ΔP = Ps - Pe and determines whether the differential pressure ΔP is within a predetermined range (step S205).

[0108] In step S205, if the differential pressure ΔP is within a predetermined range, the supply of gas G is continued (step S206). If the differential pressure ΔP deviates from the predetermined range, the determination unit 57 determines that there is a connection abnormality or a flow path abnormality and terminates or stops the gas supply (End).

[0109] In the above explanation, pressure was used as an example of a measured value, but the technology of this disclosure is not limited to this. In addition to pressure, other measured values ​​include the flow rate or flow velocity of gas G.

[0110] The first measuring means is located in the gas supply channel 31 connecting the gas supply nozzle 41 and the gas supply source 32. Examples of the first measuring means include a pressure monitor 72, a flow rate sensor 33, a flow rate sensor 70, or a flow velocity sensor 73. The second measuring means is located in the gas discharge channel 74 connecting the gas discharge nozzle 43 to the outside. Examples of the second measuring means include a flow rate sensor 75, a pressure sensor (not shown), or a flow velocity sensor (not shown) located in the gas discharge channel 74. The determination unit 57 determines that the connection between the FOUP 10 and the gas nozzles 41 and 43 is normal if the difference between a first measured value measured by the first measuring means and a second measured value of the same type as the first measured value measured by the second measuring means is within a predetermined range, or if the ratio of each measured value is within a predetermined range.

[0111] <Third Embodiment> Next, a third embodiment of the technology of this disclosure will be described with reference to Figure 8. Note that the same reference numerals are used for the components described above, and their descriptions are omitted. Figure 8 shows a control flow S3 in which the connection state is determined based on the value of the drive load before the start of gas G supply (step S103).

[0112] After the nozzle control unit 54 controls the drive mechanism 44 to raise the gas nozzles 41 and 43 and move them to the ventilation position connected to the FOUP 10, the detection unit 55 detects the value of the drive load of the drive mechanism 44 (step S304). In the electric type, the value of the drive load is detected as, for example, the drive current, torque command value, or torque limit reached signal. In the air type, the value of the drive load is detected as, for example, the drive air pressure, head chamber pressure, or lifting air pressure.

[0113] The determination unit 57 then compares the drive load value obtained by the detection unit 55 with a predetermined range stored in the storage unit 52 to determine whether the drive load value is within the predetermined range (step S305). The predetermined range is defined by a lower limit and an upper limit. In one example of an electric system, the lower limit can be set to a value higher than the holding current level when the reaction force of the FOUP 10 disappears, and the upper limit can be set to a value lower than the value indicating overpressure. In one example of an air system, the lower limit can be set to a value on the low-pressure side indicating insufficient contact, and the upper limit can be set to a value on the high-pressure side indicating excessive pressing or supply abnormality. The drive load value will be within the predetermined range if the gas supply nozzle 41 and gas discharge nozzle 43 are properly connected to the nozzle ports 14 and 15. On the other hand, if there is insufficient contact, the FOUP 10 is lifted, misalignment with respect to the nozzle ports 14 and 15, foreign matter is caught, excessive pressing or malfunction of the drive mechanism 44, the drive load value may be outside the predetermined range. If the drive load value is within a predetermined range, the determination unit 57 determines that the connection between the FOUP 10 and the gas nozzle is normal. If the drive load value is outside the predetermined range, the determination unit 57 determines that the connection between the FOUP 10 and the gas nozzle is abnormal, and the gas supply control unit 53 does not start supplying gas G (End).

[0114] If the determination unit 57 determines that the drive load value is within a predetermined range, the gas supply control unit 53 starts supplying gas G (step S103). The following operations are the same as in the first embodiment, so their explanation is omitted.

[0115] In a configuration that uses both the drive load value and the measured value, both the mechanical contact state and the sealing performance in the gas flow path are confirmed. If the drive load value is within a predetermined range but the measured value is outside the predetermined range, the determination unit 57 can determine that it is an abnormal connection where mechanical contact is established but the sealing performance is insufficient. Also, if the measured value is within a predetermined range but the drive load value is outside the predetermined range, it can be determined that there is excessive pressure, insufficient contact, or a malfunction in the drive mechanism.

[0116] In the embodiment described above, the detection unit 55 determines whether the connection between the FOUP 10 and the gas nozzle is normal or abnormal based on the value of the drive load detected. With this configuration, it is possible to determine whether the gas nozzle is actually pressed against the FOUP 10 from the drive current, drive air pressure, or torque signal, thereby suppressing the supply of gas G in a state of insufficient connection, and enabling more accurate detection and suppression of gas G leakage and insufficient replacement within the FOUP 10.

[0117] Furthermore, the determination unit 57 determines that the connection between the FOUP 10 and the gas nozzle is normal when the value of the drive load is within a predetermined range. With this configuration, by setting lower and upper limits within the predetermined range, both a state of insufficient contact reaction force and a state of excessive pressing force can be determined as abnormal. This prevents not only gas G leakage due to poor connection, but also lifting, tilting, or damage to the nozzle ports 14 and 15 of the FOUP 10 due to excessive pressure from the gas nozzle.

[0118] In the above embodiment, the connection between the FOUP 10 and the gas nozzles 41 and 43 is determined to be normal or abnormal based on the measured value of a measuring means that measures at least one of the pressure, flow rate, and flow velocity of the gas G. This configuration allows for confirmation not only of the mechanical pressing state but also of whether the gas G is flowing properly inside the FOUP 10, thus enabling direct evaluation of the sealing performance and more reliable detection of gas G leakage.

[0119] Furthermore, the determination unit 57 determines that the connection between the FOUP 10 and the gas nozzles is normal if the measured value when gas G is supplied from the gas nozzles 41 and 43 is within a predetermined range. With this configuration, the connection status can be determined using the pressure, flow rate, or flow velocity during gas G supply. By setting lower and upper limits within a predetermined range, it is possible to detect abnormalities such as a drop due to leakage or insufficient supply, an increase due to poor discharge or blockage, or excessive supply, thus enabling response to connection abnormalities that occur during purging.

[0120] Furthermore, in a configuration that includes a control unit 50 that determines whether the connection between the FOUP 10 and the gas nozzle is normal or abnormal based on the drive load value and measured values, the mechanical contact state of the gas nozzle and the sealing state of the gas flow path can be checked in a dual manner. This makes it possible to detect situations where the drive current is normal but the sealing performance is insufficient, or abnormal pressure that is difficult to determine from the measured values ​​of the gas flow path alone, thereby improving the reliability of the connection determination.

[0121] In the above-described embodiment, a case was explained in which the connection between the FOUP 10 and the gas nozzle is determined to be normal when the value of the drive load is within a predetermined range and the measured value when gas G is supplied from the gas nozzle is within a predetermined range. In this configuration, since the normal determination is made only when both the mechanical contact and the gas flow state are normal, gas leakage and insufficient replacement within the FOUP 10 can be detected with high accuracy and suppressed.

[0122] As an example of the technology disclosed herein, a configuration is given in which the measurement means is installed only in the gas discharge channel 74 that connects the gas discharge nozzle 43 to the outside. In this configuration, even if a connection failure occurs in any of the multiple gas supply nozzles 41, the change in the gas G discharged as it passes through the FOUP 10 will be reflected on the discharge side, so the abnormality can be detected by consolidating it at a single point on the discharge side. This makes it possible to detect connection abnormalities on the gas supply nozzle 41 side while suppressing the number of sensors.

[0123] Furthermore, a configuration in which the measuring means is installed only in the gas supply channel 31 connecting the gas supply nozzle 41 and the gas supply source 32 was also described. In this configuration, the total flow rate, supply pressure, or supply velocity supplied from the gas supply source 32 to multiple gas supply nozzles 41 can be determined in a common channel. Therefore, the overall connection failure can be monitored at a single point before branching, and a simple and inexpensive configuration can be realized in applications where it is not necessary to individually identify which nozzle is faulty.

[0124] In the above embodiment, the connection between the FOUP 10 and the gas nozzle may be determined to be normal if the difference or ratio between the first measured value in the gas supply channel 31 and the second measured value of the same type as the first measured value in the gas discharge channel 74 is within a predetermined range. In this configuration, abnormalities can be determined based on the relative relationship between the supply side and the discharge side. As a result, connection abnormalities can be detected without relying solely on absolute values, even if there are fluctuations in gas supply conditions, changes in the set flow rate, or pressure fluctuations on the supply source side.

[0125] In the above embodiment, after the drive mechanism 44 moves the gas nozzle to a position where it can be connected to the FOUP 10, the detection unit 55 detects the value of the drive load, and if the value of the drive load is within a predetermined range, gas G may be supplied from the gas nozzle. This configuration prevents gas G from being supplied before the mechanical connection is confirmed. This suppresses the ejection of gas G due to a poor connection and suppresses gas leakage at the start of purging.

[0126] While embodiments of this disclosure have been described above with reference to the attached drawings, this disclosure is not limited to the contents of the embodiments described above, and modifications can be made as appropriate without departing from this disclosure. In other words, all other embodiments, examples, and operational techniques made by those skilled in the art based on these embodiments are, of course, included in the scope of this disclosure.

[0127] Furthermore, the effects described in the above embodiments are descriptive or illustrative, and are not limited to those described in the above embodiments. In other words, the technology relating to this disclosure may produce other effects that would be obvious to a person of ordinary skill in the art of this disclosure from the descriptions in the above embodiments, in addition to or in lieu of the effects described in the above embodiments.

[0128] The control unit 50 in each of the above embodiments may include various processors other than the CPU. Examples of such processors include PLDs (Programmable Logic Devices) such as FPGAs (Field-Programmable Gate Arrays) whose circuit configuration can be changed after manufacturing, and dedicated electrical circuits that are processors with circuit configurations specifically designed to perform specific processing, such as ASICs (Application Specific Integrated Circuits). The control method according to this disclosure may be executed by one of the various processors, or by a combination of two or more processors of the same or different types (for example, multiple FPGAs, or a combination of a CPU and an FPGA). More specifically, the hardware structure of these various processors is an electrical circuit that combines circuit elements such as semiconductor elements.

[0129] Furthermore, the program for executing the control method relating to this disclosure may, but is not limited to, being pre-stored (installed) in the ROM or storage unit 52. The program may be provided in a form recorded on a non-transitory recording medium such as a CD-ROM (Compact Disk Read Only Memory), DVD-ROM (Digital Versatile Disk Read Only Memory), or USB (Universal Serial Bus) memory. Alternatively, the program may be provided in a form that can be downloaded from an external device via a network. [Explanation of Symbols]

[0130] 1 Load port 10 FOUP 11 Main body 12 Openings 14 Supply nozzle ports 15 Discharge nozzle port 20 mounting platform 21 Dog Plate 22 Support pins 30 Gas purging device 31 Gas supply channel 32 Gas supply sources 33 Flow Sensor 35 Mass Flow Controller 36 Upstream valve 37 Downstream valve 38 Speed ​​Controller 39 Gas filter 41 Gas supply nozzle 43 Gas discharge nozzle 44 Drive mechanism 50 Control Unit 51 Controllers 52 Storage section 53 Gas supply control unit 54 Nozzle control unit 55 Detection unit 56 Measurement Unit 57 Judgment section 70 Flow Sensor 72 Pressure Monitor 73 Flow velocity sensor 74 Gas exhaust channel 75 Flow Sensor 100 Gas Purge System G Gas W board

Claims

1. A gas nozzle for supplying gas into a container that houses a substrate and is placed on a mounting base, or for discharging the gas from the container, A drive mechanism for moving the gas nozzle between a ventilation position connected to the container and a standby position separated from the container, A detection means for detecting the value of the drive load of the drive mechanism, The system includes a control unit that determines whether the connection between the container and the gas nozzle is normal or abnormal based on the value of the drive load detected by the detection means. Gas purging device.

2. The gas purging device according to claim 1, wherein the control unit determines that the connection between the container and the gas nozzle is normal when the value of the drive load is within a predetermined range.

3. A gas nozzle for supplying gas into a container that houses a substrate and is placed on a mounting base, or for discharging the gas from the container, A drive mechanism for moving the gas nozzle between a ventilation position connected to the container and a standby position separated from the container, A detection means for detecting the value of the drive load of the drive mechanism, A measuring means is provided in the gas flow path connected to the gas nozzle, for measuring at least one of the pressure, flow rate, and flow velocity of the gas flowing through the gas flow path. The system includes a control unit that determines whether the connection between the container and the gas nozzle is normal or abnormal based on the value of the drive load detected by the detection means and the value measured by the measuring means. Gas purging device.

4. The gas purging device according to claim 3, wherein the control unit determines that the connection between the container and the gas nozzle is normal when the value of the drive load is within a predetermined range and the measured value is within a predetermined range.

5. The gas nozzle, when connected to the container, includes a gas supply nozzle for supplying gas into the container and a gas discharge nozzle for discharging the gas from the container. The gas purging device according to claim 3 or 4, wherein the measuring means is disposed in a gas discharge channel connecting the gas discharge nozzle and the outside from which the gas is discharged.

6. The gas nozzle, when connected to the container, includes a gas supply nozzle for supplying gas into the container and a gas discharge nozzle for discharging the gas from the container. The gas purging device according to claim 3 or 4, wherein the measuring means is disposed in a gas supply channel connecting the gas supply nozzle and the gas supply source that supplies the gas.

7. The gas nozzle, when connected to the container, includes a gas supply nozzle for supplying gas into the container and a gas discharge nozzle for discharging the gas from the container. The measuring means comprises a first measuring means disposed in a gas supply channel connecting the gas supply nozzle and the gas supply source that supplies the gas, and a second measuring means disposed in a gas discharge channel connecting the gas discharge nozzle and the outside from which the gas is discharged. The gas purging device according to claim 3, wherein the control unit determines that the connection between the container and the gas nozzle is normal when the difference or ratio between a first measured value measured by the first measuring means and a second measured value of the same type as the first measured value measured by the second measuring means is within a predetermined range.

8. The gas purging device according to claim 4, wherein the control unit moves the gas nozzle to a ventilation position connected to the container by the drive mechanism, and before supplying the gas from the gas nozzle, the detection means detects the value of the drive load, and if the value of the drive load is within a predetermined range, the gas is supplied from the gas nozzle.

9. A gas nozzle for supplying gas into a container that houses a substrate and is placed on a mounting base, or for discharging the gas from the container, A drive mechanism for moving the gas nozzle between a ventilation position connected to the container and a standby position separated from the container, A detection means for detecting the value of the drive load of the drive mechanism, A control method for a gas purging device comprising a control unit that controls the operation of each part, The control unit determines that the connection between the container and the gas nozzle is normal when the value of the drive load is within a predetermined range.

10. A gas nozzle for supplying gas into a container that houses a substrate and is placed on a mounting base, or for discharging the gas from the container, A drive mechanism for moving the gas nozzle between a ventilation position connected to the container and a standby position separated from the container, A detection means for detecting the value of the drive load of the drive mechanism, A measuring means is provided in the gas flow path connected to the gas nozzle, for measuring at least one of the pressure, flow rate, and flow velocity of the gas flowing through the gas flow path. A control method for a gas purging device comprising a control unit that controls the operation of each part, After the control unit moves the gas nozzle to the ventilation position connected to the container by the drive mechanism, and before supplying the gas from the gas nozzle, it has the detection means detect the value of the drive load, and if the value of the drive load is within a predetermined range, it supplies the gas from the gas nozzle. Furthermore, a control method for determining that the connection between the container and the gas nozzle is normal when, while the gas is being supplied from the gas nozzle, the value of the drive load is within a predetermined range and the measured value measured by the measuring means is within a predetermined range.

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