Loading Port

Abstract

[Problem] To provide a load port which can separate a container and a lid without causing a trouble of an error stop of the entirety of a transport device, even when a seal member is adhered or the friction of the seal member is large in the container. [Solution] According to the present invention, when a sensor has detected normal loading of a sealed container, a load port control unit causes a door opening operation of the sealed container to be executed in a first operation sequence. When the sensor has detected a loading abnormality of the sealed container, the door opening operation is retried in a second operation sequence capable of more reliably executing the door opening operation of the sealed container, thereby preventing the transport device from stopping.

Description

[Technical field]

[0001] The present invention relates to a lid opening and closing device for attaching and detaching the lid of a sealable container that stores and transports a plurality of semiconductor wafers at predetermined intervals, and relates to a load port door that is integrated with the lid of a FOUP (Front-Opening Unified Pod), which is a sealed container, to attach and detach the lid from the FOUP body. [Background technology]

[0002] Conventionally, the surface treatment of semiconductor wafers has been carried out in so-called clean rooms maintained in a highly clean environment, but as semiconductors become finer, maintaining the entire clean room, which contains many processing equipment, at a high level of cleanliness has required large capital investment and maintenance costs, which has become a major obstacle in terms of cost. Therefore, efforts have been made to improve the yield of semiconductor manufacturing processes by maintaining the entire clean room at a relatively low level of cleanliness and keeping only the microenvironment (mini-environment) inside the processing equipment that processes the wafer surface at a high level of cleanliness.

[0003] The manufacturing process of semiconductor wafers requires many surface treatments and inspections, and many dedicated processing devices are installed in the clean room to perform various surface treatments and inspections on the wafer surface. The wafers being processed are stored in FOUPs with highly clean interiors, and are transported between the processing devices in the clean room to undergo various processing processes. The transport of the FOUPs to the processing devices and the progress of each processing process are managed by a host computer. Each processing device that performs each processing process is equipped with a wafer transport device called an EFEM (Equipment Front End Module), and this EFEM is equipped with multiple lid opening and closing devices called load ports that place the FOUPs and open and close the FOUP lids. The inside of the EFEM is maintained at a higher pressure than the environment in the clean room, and dust in the clean room cannot enter the microenvironment (minienvironment) of the EFEM. As a result, the wafers stored inside the FOUPs and transported from the previous process are transported to the next processing device without any dust adhering to them.

[0004] The configuration of FOUPs and load ports that attach and detach FOUP lids is regulated by the SEMI standard established by the international industry organization SEMI (Semiconductor Equipment and Materials International), and many manufacturers manufacture FOUPs and load ports that comply with this standard. FOUPs generally consist of a FOUP body that stores wafers and a lid that closes the opening formed in the FOUP body, and inside the FOUP body, shelves are formed at a specified interval in the vertical direction, and each shelf can store one wafer at a time. A seal member such as a packing is fixed to the periphery of the lid that closes the opening of the FOUP body, and this seal member provides an airtight seal between the periphery of the FOUP opening and the lid.

[0005] Patent Document 1 describes a conventional load port. The load port includes an advance / retract mechanism for placing a FOUP and moving the FOUP forward and backward, a load port door that is integrated with the FOUP lid and opens and closes the lid, and a lifting mechanism for moving the door up and down. When the FOUP is placed at a predetermined position on the advance / retract mechanism, the load port fixes the FOUP on the placement stage by a fixing member provided in the advance / retract mechanism, and the advance / retract mechanism moves the stage forward toward the door to bring the FOUP lid into contact with the load port door. When the lid and the load port door come into contact with each other, the load port door and the lid are integrated by an integration means provided in the load port door, and the lock mechanism of the lid is released. The stage is then moved backward to separate the FOUP body and the lid. After the FOUP body and the lid are separated, the lifting mechanism lowers the integrated lid and load port door to a position where they do not interfere with the transfer of wafers. By the above operation, the lid of the FOUP is opened, and the transfer robot of the transfer device becomes capable of transferring wafers into and out of the FOUP body. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-298075 A Summary of the Invention [Problem to be solved by the invention]

[0007] In semiconductor manufacturing processes, the operating speed of the load port when opening and closing the lid is set as fast as possible in order to increase the number of wafers processed per unit time. In conventional load ports, when the FOUP body and the lid are separated, the FOUP body and the lid are moved relative to each other at high speed. This causes friction between the seal member on the periphery of the lid and the FOUP body, and adhesion of the seal member, which prevents the lid from smoothly separating from the body, causing the FOUP body to float up from the advance / retract mechanism. In addition, if the door opening operation is continued while the FOUP body is floating up, a problem occurs in which the FOUP body falls into the advance / retract mechanism when the lid is completely removed from the body. The impact of the FOUP body falling causes the wafers stored in the FOUP to shift position within the FOUP, or the wafers collide with the shelf due to the impact of the fall, generating dust. In addition, when the FOUP body floats up, the presence sensor on the stage reacts and causes an error, causing the entire transport device equipped with multiple load ports to stop. [Means for solving the problem]

[0008] In order to solve the above problems, the load port of the present invention has the following features: a stage for mounting, at a predetermined position, a sealed container having a container body for accommodating a wafer and a lid for airtightly closing the container body; a sensor for detecting a state in which the sealed container is placed on the stage; a stage driving mechanism for moving the stage forward and backward; a load port door which is joined to the lid to form an integrated body and then separates the lid from the container body to open the sealed container; a door lifting mechanism for lifting and lowering the load port door; a load port control unit that stores a plurality of operation procedures for operating the stage drive mechanism, the load port door, and the door lifting mechanism, and controls the operations of the stage drive mechanism, the load port door, and the door lifting mechanism based on the operation procedures, The load port control unit includes: in order to separate the lid from the container body and open the sealed container, based on a first operation procedure, controlling the stage drive mechanism and the door lifting mechanism to move the stage back to the docking position at a first speed from a state in which the load port door and the lid are joined and integrated at the docking position; When the sensor detects an abnormality in the placement of the sealed container during the door opening operation according to the first operation procedure, the sealed container is returned to the docking position, and then the door opening operation is controlled to be re-executed based on a second operation procedure different from the first operation procedure. It is characterized by the following.

[0009] With the above configuration, the container body and lid of the sealed container are opened by a second operation procedure that can more reliably separate the container body and lid, separate from the first operation procedure in which the container body floats up, so that even if the container body floats up once due to the door opening operation by the first operation procedure, the lid can be separated by the door opening operation by the second operation procedure without the container body floating up from the stage. This makes it possible to prevent the occurrence of problems such as the entire transport device, including the normal load port, frequently stopping operation due to a malfunction in the door opening operation.

[0010] The second operation procedure of the door opening operation executed by the load port control unit of the present invention may be configured to perform the operation at a speed slower than that of the first operation procedure, and the load port control unit may be configured to perform the second operation procedure at least until the lid of the sealed container and the container body are separated. The second operation procedure may be a processing procedure for moving to an undocking position by intermittently repeating a small retreating operation (intermittently repeating a retreating operation and a stop), and the load port control unit may be configured to perform the second operation procedure at least until the lid of the sealed container and the container body are separated. Furthermore, the second operation procedure may be a setting for moving the stage to a predetermined retreating position, and then temporarily moving the stage forward a distance shorter than the distance to the retreating position, and the load port control unit may be configured to perform the second operation procedure at least until the lid of the sealed container and the container body are separated.

[0011] Furthermore, the load port control unit of the present invention is characterized in that the door is raised and lowered in the vertical direction within a predetermined operating range by the door lifting mechanism at least until the lid of the sealed container and the container body are separated. With the above configuration, in addition to the operation of moving the stage back and forth, the operation of raising and lowering the container lid in the vertical direction is performed, so that the lid can be smoothly separated from the container body.

[0012] The vertical movement range of the door is desirably smaller than the vertical gap between the container body and the lid. With the above configuration, it is possible to prevent the container body from colliding with the lid when the lid is moved vertically, and to prevent the container body from floating up due to the vertical movement. It is also desirably smaller than the gap between the door and an airflow adjustment plate disposed around the door. With the above configuration, it is possible to prevent dust generation due to collision between the door and the airflow adjustment plate.

[0013] In addition, the various second operation procedures exemplified above can be used in appropriate combination. Furthermore, when the lid cannot be separated even with the second operation procedure, it is also possible to configure to execute various second operation procedures a predetermined number of times. In addition, it is also possible to configure to execute various different second operation procedures in order of priority by appropriately prioritizing the second operation procedures. For example, when the lid cannot be separated from the container body even if the stage is moved at a speed slower than the moving speed of the first operation procedure as the second operation procedure, it is possible to perform an operation in which the movement of the stage is divided as a third operation procedure and the movement and stopping are repeated intermittently. In addition, it is also possible to configure to assign an order of priority to the operation procedures described above as the second operation procedure, and to execute them in combination as the third and fourth operation procedures. Effect of the Invention

[0014] According to the load port of the present invention, even if an abnormality occurs when opening the door of a sealed container using the normal door-opening operation procedure due to reasons such as adhesion of the sealing members or high friction of the sealing members, the door-opening process is performed using a second operation procedure which allows for more reliable opening of the door, thereby preventing trouble such as the entire transport apparatus stopping every time an abnormality occurs in the door opening and improving the operating efficiency of the entire system. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a cross-sectional view showing an EFEM according to one embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view showing a load port according to one embodiment of the present invention; [Diagram 3] 1A and 1B are diagrams showing a stage provided on a load port according to one embodiment of the present invention, in which (a) is a diagram showing the stage provided on the load port of this embodiment as viewed from above, and (b) is a schematic diagram of a FOUP for explaining the main parts of the stage as viewed from the side. [Figure 4]1A and 1B are diagrams showing a port door and its surrounding and internal mechanisms provided on a load port according to one embodiment of the present invention, in which (a) is a diagram showing the port door from the side where the stage is placed, and (b) is a schematic diagram of the lid opening and closing mechanism shown in the unlocked state after the latch key has been rotated to the left. [Diagram 5] 1A and 1B are diagrams showing a FOUP body and a lid used in the present invention, in which (a) is a perspective view showing a FOUP body storing a wafer W and the lid separated from the body, (b) is a perspective view showing the inside of the lid, and (c) is a diagram showing the bottom surface of the FOUP. [Figure 6] FIG. 2 is a diagram showing the internal structure of a lid used in the present invention. [Figure 7] 5A and 5B are enlarged partial cross-sectional views showing the position of the lid relative to the FOUP body and the state of the sealing member, in which (a) shows the FOUP body and the lid in an unlocked state, and (b) shows the locked state. [Figure 8] 1A and 1B are enlarged partial cross-sectional views showing the structure of a biasing mechanism that presses the lid against the FOUP, in which (a) and (b) show a state in which the lid is not pressed against the FOUP body, and (c) shows a state in which the lid is pressed against the FOUP body. [Figure 9] 1A and 1B are schematic diagrams showing an example of a detection sensor provided on a load port of the present invention, in which (a) shows a normal state in which a FOUP is correctly placed and the optical path is blocked by a detection pin, and (b) shows an error state in which the light receiving unit receives light because the FOUP is tilted. [Figure 10] 4A and 4B are diagrams showing the placement state of a FOUP 30, in which (a) is a side view showing the FOUP in the docking position, and (b) is a side view showing the state in which the rear part of the FOUP is raised by the door-opening operation because the sealing member is adhered to the flange. [Figure 11]FIG. 11 is a diagram comparing the effects of the door-opening operation using the first and second operating procedures, where (a) is a diagram showing, with solid lines, the elapsed time and the distance traveled when the stage is moved using the first operating procedure, (b) is a diagram showing, with solid lines, the elapsed time and the distance traveled when the door-opening operation is performed using the second operating procedure, which moves the stage at a slower moving speed than the first operating procedure, and (c) is a diagram showing the case of the second operating procedure, in which the stage is moved to the undocking position by repeatedly moving short distances and stopping. [Figure 12] 13A shows another example of the second operating procedure, where (a) is a diagram showing an example of the door opening operation using the second operating procedure by repeatedly moving backward and forward to the undocking position, and (b) and (c) are diagrams showing the second operating procedure in which the stage is moved to the unloading position while vibrating the load port door up and down. [Figure 13] 2 is a block diagram illustrating a portion of the configuration of a load port according to an embodiment of the present invention; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an outline of an EFEM7, which is a transfer device that transfers a wafer W stored in a FOUP30 between the FOUP30 and a wafer processing device 6 without exposing the wafer W to the external environment. The EFEM7 includes at least a load port 8 that places the FOUP30 and opens and closes the door of the FOUP30, a transfer robot 9 that takes out the wafer W stored inside the FOUP30 and transfers it to the processing device, and an FFU (Fun Filter Unit) 10 that supplies clean air to the internal space of the EFEM7. The transfer operation in which the load port 8 and the transfer robot 9 work together is controlled by a control device 17 arranged in the EFEM7. Although only one FOUP30 is shown in FIG. 1, a plurality of FOUPs 30 are usually arranged in a horizontal direction.

[0017] The internal space of the EFEM7 is a clean space covered by a frame 18 and a cover fixed to the frame 18, and the FFU 10 is installed on the ceiling of this space. The FFU 10 filters the air introduced from the outside by a fan and supplies the clean air as a downflow to the internal space of the EFEM7. Furthermore, a bottom cover 13 having a plurality of openings opened at a predetermined opening ratio is arranged on the floor surface of the EFEM7, and the clean air supplied from the FFU 10 passes through the internal space of the EFEM7 and is discharged to the outside of the EFEM7 from the openings of the bottom cover 13. The flow rate of the clean air supplied from the FFU 10 and the opening ratio of the bottom cover 13 are adjusted so that the pressure in the internal space of the EFEM7 is higher than the external air pressure, preventing dust generated outside the EFEM7 from flowing into the internal space of the EFEM7.

[0018] FIG. 2 is a cross-sectional view showing a load port 8 according to an embodiment of the present invention. FIG. 3(a) is a top view of a stage 21 provided on the load port 8 of the embodiment shown in FIG. 2, and FIG. 3(b) is a schematic side view of the stage 21. For ease of explanation, only the FOUP body 1 and the lid 2 are shown in cross section. The load port 8 serves as a lid opening / closing device that removes the lid 2 of the FOUP 30 from the FOUP body 1 while preventing the outside atmosphere from entering, thereby connecting the internal atmosphere of the FOUP 30 to the internal atmosphere of the EFEM 7. This allows the transfer robot 9 to take out and transfer the wafer W from the FOUP 30 without exposing the insides of the FOUP 30 and the EFEM 7 to the outside atmosphere.

[0019] 2, the load port 8 of this embodiment comprises a horizontal frame 20 attached to a main body frame 19 which is connected and fixed in an upright state to the frame 18 of the EFEM 7, a stage 21 on which the FOUP 30 is placed at a predetermined position, a stage drive unit 23 which is provided on the horizontal frame 20 and moves the stage 21 forward and backward in a horizontal plane, a plate 27 which is fixed to the main body frame 19 and has a port opening 26 formed therein through which the wafer W and the lid 2 of the FOUP 30 can pass, a load port door 28 which can pass through the port opening 26 and has a mechanism for being integrated with the lid 2 of the FOUP 30, and a door lift unit 29 which moves the load port door 28 up and down.

[0020] As shown in Fig. 3(b), the stage driving unit 23 of this embodiment includes a motor 31 as a driving source and a feed screw mechanism 32 connected to the motor 31. The rotation shaft of the motor 31 and the ball screw shaft of the feed screw mechanism 32 are connected by a known coupling mechanism, and the rotation of the rotation shaft of the motor 31 is transmitted to the ball screw shaft, so that the stage 21 can move to a predetermined position in the horizontal direction. As the predetermined position, the stage driving mechanism 23 can move the stage 21 to each of the positions, such as a docking position where the lid 2 of the FOUP 30 and the load port door 28 are joined and integrated, an undocking position where the FOUP body 1 and the lid 2 are separated, a retreat position where the stage driving mechanism 23 does not interfere when the load port door 28 descends after the FOUP body 1 and the lid 2 are separated, and a reference position for transferring the FOUP 30 to a means for transporting the FOUP installed in a clean room.

[0021] The door lifting / lowering unit 29 includes a motor 33 and a feed screw mechanism 34 as drive sources (see FIG. 2). A pulley is fixed to each of the rotation shaft of the motor 33 and the ball screw shaft of the feed screw mechanism 34, and a belt is stretched between these two pulleys. As a result, the rotation of the rotation shaft of the motor 33 is transmitted to the ball screw shaft of the feed screw mechanism 34, and the load port door 28 moves up and down to a predetermined position. Note that the motors 31 and 33 included in the stage driving unit 23 and the door lifting / lowering unit 29 of this embodiment are preferably stepping motors capable of controlling the angle of the rotation shaft, and the operating speed and operating distance of these motors 31 and 33 are controlled by a load port control unit 35 included in the load port 8. Also, instead of the motors 31 and 33 shown in FIG. 2 and FIG. 3 as drive sources included in the stage driving unit 23 and the door lifting / lowering unit 29, a configuration in which known cylinders utilizing fluid pressure such as air pressure or hydraulic pressure may be used.

[0022] On the upper surface of the stage 21, three kinematic pins 12-1, 12-2, and 12-3, which are cylindrical members supporting the FOUP 30, are erected at a predetermined interval so as to be located at the vertices of an isosceles triangle in a plan view (see FIGS. 3(a) and 3(b)). The kinematic pins 12-1, 12-2, and 12-3 preferably have a substantially hemispherical shape at the top. When the FOUP 30 is placed on the kinematic pins 12-1, 12-2, and 12-3, three V-groove portions 11 formed as substantially V-shaped recesses on the bottom surface of the FOUP 30 come into contact with the tops of the kinematic pins 12-1, 12-2, and 12-3, respectively, and the FOUP 30 is positioned at a predetermined position on the stage 21. Furthermore, detection sensors 36-1, 36-2, and 36-3 for detecting whether the FOUP 30 is placed in the correct position on the stage 21 are disposed near the kinematic pins 12-1, 12-2, and 12-3, respectively.

[0023] The detection sensors 36-1, 36-2, and 36-3 provided on the load port 8 of this embodiment are each composed of a detection pin, a compression spring for biasing the detection pin upward, and a transmitted light sensor. An example of a detection sensor using a transmitted light sensor is illustrated in FIG. 9. As shown in FIG. 9(a), when the FOUP 30 is correctly placed on the kinematic pins 12-1, 12-2, and 12-3, the detection pin 66 is pushed downward by the bottom surface of the FOUP 30, and the detection light 70 irradiated from the light emitting unit 71 is blocked by the detection pin 66. Therefore, the light receiving unit 72 cannot detect the detection light 70 and outputs an OFF signal. On the other hand, when the FOUP 30 is not placed or when the FOUP 30 is not correctly placed as shown in FIG. 9(b), the detection pin 66 is pushed upward by the compression coil spring 67 or the like, and the light receiving unit 72 detects the detection light 70 and outputs an ON signal (light receiving signal). This on or off signal is sent to the load port control unit 35, and the control unit recognizes whether the FOUP 30 is properly placed.

[0024] When the FOUP 30 is placed correctly so that the kinematic pins 12-1, 12-2, and 12-3 abut at predetermined positions within the V-groove portion 11 of the FOUP 30, the position of the bottom surface of the FOUP 30 is lowered a distance corresponding to the depth of the V-groove 11. If the FOUP 30 is not placed correctly, the bottom surface of the FOUP 30 will be at a higher position than if it were correctly positioned. Due to this difference in the lowered position of the bottom surface, the detection sensors 36-1, 36-2, and 36-3 send an OFF signal to the load port control unit 35 when the FOUP 30 is placed correctly, and an ON signal when it is not correctly positioned.

[0025] The height positions of the detection sensors 36-1, 36-2, 36-3 are adjusted so that all of the detection sensors 36-1, 36-2, 36-3 output an OFF signal only when the FOUP 30 is placed correctly. For example, when the FOUP 30 is placed in an inclined state because one of the kinematic pins is not placed correctly in the V-groove portion 11, at least one of the three detection sensors 36-1, 36-2, 36-3 is adjusted to be in the ON state. Therefore, the load port control unit 35 can recognize whether the FOUP 30 is placed correctly on the stage 21 by these signals transmitted from the detection sensors 36-1, 36-2, 36-3.

[0026] Furthermore, the FOUP 30 placed on the kinematic pins 12-1, 12-2, and 12-3 is locked to the stage 21 by a locking hook 37 (see FIG. 3(b)). The locking hook 37 is linked to an air cylinder (not shown), and when compressed air is supplied to this air cylinder, the piston rod of the air cylinder extends, causing the locking hook 37 to lock the FOUP 30 to the stage 21. When the compressed air supplied to the air cylinder is released, the piston rod contracts, causing the locking hook 37 to release the lock on the FOUP 30. The supply and release of compressed air to the air cylinder is switched by a solenoid valve (not shown) provided in the load port 8. The solenoid valve is provided in the middle of the piping that communicates between the compressed air supply source and the air cylinder, and its operation is controlled by the load port control unit 35.

[0027] Furthermore, the stage 21 may be provided with an ID reader (not shown) that reads ID information individually assigned to each FOUP 30 in order to manage the processing steps of the wafers W. Note that the ID reader may be a barcode reader that reads a barcode provided on the FOUP 30, or an RFID (Radio Frequency Identifier) ​​reader that transmits radio waves to an ID tag provided on the FOUP 30 and receives radio waves returned from the ID tag.

[0028] 4A and 4B are diagrams showing the port door 28 and its peripheral mechanism of the load port 8 of this embodiment, in which FIG. 4A is a diagram of the port door 28 as viewed from the side where the stage 21 is arranged, and FIG. 4B is a schematic diagram showing the lid opening / closing mechanism 39 in a state where the latch key 15 is rotated left to unlock. The load port door 28 includes a registration pin 38 for positioning the lid 2 of the FOUP 30 relative to the load port door 28, a latch key 15 for engaging with a locking mechanism 51 (see FIG. 6) provided on the lid 2 to lock and unlock the lid 2, and a lid opening / closing mechanism 39 for rotating the latch key 15. The registration pins 38 are substantially cylindrical members with a diameter of about 9 mm and are located at the upper left and lower right of the front of the load port door 28 shown in FIG. 4. Adsorption pads 40 made of a flexible material such as silicone rubber are provided around each registration pin 38. Furthermore, a flow path for sucking (vacuum adsorption) the lid 2 is formed in the registration pins 38, and this flow path is connected to a vacuum source (not shown) provided outside the apparatus. The lid 2 of the FOUP 30 that comes into contact with the load port door 28 is positioned at a predetermined position relative to the load port door 28 by the registration pins 38, and the lid 2 is sucked in by the vacuum adsorption force from the vacuum source, and the load port door 28 and the lid 2 are integrated together.

[0029] The latch keys 15 are substantially T-shaped members arranged to protrude from the surface of the load port door 28, and a pair of latch keys 15 are provided on the left and right sides of the front of the load port door 28. Each latch key 15 is rotated clockwise and counterclockwise by a lid opening / closing mechanism 39 provided inside the load port door 28. The lid opening / closing mechanism 39 of this embodiment has an air cylinder 41 as a driving source, and a cam mechanism 42 connected to the piston rod moves forward and backward to rotate the latch key 15 in conjunction with the air cylinder 41. The supply and release of compressed air from the air cylinder 41 to the air cylinder 41 is controlled by the load port control unit 35. With the above configuration, after the load port door 28 and the lid 2 are integrated, the latch key 15 rotates in a predetermined direction to unlock the lid 2 and make it separable from the FOUP body 1. The latch key 15 rotates in the opposite direction to lock the lid 2 of the FOUP 30 so that it cannot be separated from the FOUP body 1.

[0030] In addition to the above configuration, the load port 8 is provided with a mapping sensor 43 for detecting whether or not a wafer W is accommodated on each shelf formed inside the FOUP 30 (see FIG. 4(a)). As the mapping sensor 43 provided in the load port 8 in this embodiment, a transmitted light sensor in which a light source and a light receiving unit are arranged at an interval on the left and right is used. The mapping sensor 43 in this embodiment is attached to the load port door 28 in a state in which it can swing toward the inside of the FOUP body 1. When the load port door 28 is lowered to a predetermined height position, both the light source and the light receiving unit arranged on the left and right of the mapping sensor 43 enter the inside of the FOUP body 1 toward the inside of the FOUP body 1 to an extent that they do not come into contact with the wafer. In this state, when the mapping sensor 43 is lowered together with the load port door 28 by the door lifting unit 29, the presence or absence of the wafer W on each shelf is detected sequentially by detecting whether or not the light from the light source is blocked by the edge of the wafer W placed on each shelf. An air cylinder (not shown) is provided as a drive source for a sensor drive mechanism that moves the mapping sensor 43 back and forth toward the inside of the FOUP body 1. The drive of the mapping sensor 43 and each drive mechanism such as the door lifting / lowering unit 29 are controlled by the load port control unit 35, and a detection signal from the mapping sensor 43 is input to the load port control unit 35. The detection signal from the mapping sensor 43 makes it possible to detect the presence or absence of wafers W on all shelves in the FOUP body 1.

[0031] Next, a description will be given of the FOUP 30, which is an airtight container for accommodating the wafer W. FIG. 5(a) is an exploded perspective view showing the FOUP body 1 and the lid 2 in which the wafer W is accommodated, and FIG. 5(b) is a perspective view showing the inside of the lid 2. FIG. 5(c) is a view showing the bottom of the FOUP 30. The FOUP 30 is composed of the FOUP body 1, which accommodates the wafer W on shelves formed at intervals in the vertical direction, and the lid 2, which closes the FOUP body 1 airtightly. An opening 44 for inserting and removing the wafer W is formed on one side of the FOUP body 1, and this opening 44 is closed by the lid 2. Three positioning grooves 11 formed in a substantially V-shape are arranged at predetermined positions on the bottom of the FOUP body 1, which come into contact with the kinematic pins 12-1, 12-2, and 12-3, respectively, to determine the position of the FOUP 30 relative to the stage 21. An engagement portion 45 is formed at the bottom of the FOUP body 1, and this engagement portion 45 engages with a locking hook 37 (FIG. 3(b)) of the stage 21, thereby fixing the FOUP body 1 to the stage 21. The bottom of the FOUP body 1 is provided with an injection port 46 for injecting a purge gas to replace the atmosphere inside the FOUP 30, and an exhaust port 47 for exhausting gas remaining within the FOUP 30 to the outside of the FOUP 30, as required.

[0032] Furthermore, an opening flange 48 is provided around the periphery of the opening 44 of the FOUP body 1 so as to surround the opening 44. Recesses 49 are provided on the upper and lower surfaces of the opening flange 48 facing the opening 44, into which a locking member 55 of the lid 2, which will be described later, is inserted. A seal member 50 is provided around the periphery of the lid 2 on the FOUP body 1 side, and this seal member 50 comes into close contact with a second flat surface 58 (see FIG. 7) formed on the inside of the opening flange 48, thereby hermetically sealing the internal space of the FOUP body 1.

[0033] The lid 2 is composed of a surface plate 2a and a back plate 2b that fit together, and a locking mechanism 51 (see FIG. 6) for locking and unlocking the FOUP body 1 and the lid 2 is provided between the surface plate 2a and the back plate 2b. A seal member 50 and a groove for sandwiching and fixing the seal member 50 between the surface plate 2a and the back plate 2b are provided on the periphery of the lid 2 as shown in FIG. 7, and the seal member 50 maintains the airtightness between the FOUP body 1 and the lid 2. Furthermore, the back plate 2b is provided with a retainer 52 for fixing the wafer W accommodated in the FOUP body 1 at a predetermined position (see FIG. 5(b)). The surface plate 2a is provided with a registration pin hole 4 into which a registration pin 38 provided on the load port door 28 is inserted, and a key hole 53 for engaging with a latch key 15 of a lid opening / closing mechanism 39 described later.

[0034] 6 is a diagram showing the internal structure of the lid 2. The locking mechanism 51 arranged inside the lid 2 is composed of two disk-shaped members 54 arranged at positions corresponding to the latch keys 15 equipped on the load port door 28, and locking members 55 arranged above and below the disk-shaped members 54 and moving up and down in conjunction with the rotation of the disk-shaped members 54. Each disk-shaped member 54 is provided with cam grooves 56 in two locations over approximately 90° in the circumferential direction. The cam grooves 56 are formed so that the radial distance from the center of rotation of the disk-shaped members 54 increases in the clockwise direction as viewed in the drawing.

[0035] The base end of the locking member 55 is connected to the cam groove 56 via a pin. The locking member 55 is disposed inside the lid 2 so as to be vertically movable, and with the above-mentioned configuration, the disk-shaped member 54 rotates 90° clockwise, whereby the connecting pin is pushed by the peripheral portion of the cam groove 56. As a result, the tip of the locking member 55 protrudes from the upper and lower surfaces of the lid 2 and enters the recess 49 of the opening flange 48, locking the FOUP 30 and the lid 2. As the disk-shaped member 54 rotates 90° counterclockwise, the connecting pin is pulled inward by the peripheral portion of the cam groove 56, whereby the tip of the locking member 55 retracts. As a result, the locking member 55 retracts from the recess 49 of the opening flange 48, unlocking the FOUP 30 and the lid 2.

[0036] A substantially rectangular latch key hole 53 is provided in the center of the disk-shaped member 54. When the FOUP 30 fixed on the stage 21 of the load port 8 moves forward by the stage 21 and comes into contact with the load port door 28, the tip of the latch key 15 arranged on the load port door 28 fits into this latch key hole 53. Then, the lid opening / closing mechanism 39 is actuated, causing the latch key 15 and disk-shaped member 54 to rotate forward, unlocking the FOUP 30 and the lid 2. Meanwhile, when the lid opening / closing mechanism 39 is actuated in the opposite direction, the latch key 15 and disk-shaped member 54 are rotated backward, locking the FOUP 30 and the lid 2.

[0037] FIG. 7 is an enlarged partial cross-sectional view showing the state of the seal member 50 with respect to the FOUP body 1 when the lid 2 is unlocked or locked, FIG. 7(a) shows the state in which the FOUP body 1 and the lid 2 are unlocked, and FIG. 7(b) shows the state in which the FOUP body 1 and the lid 2 are locked. The seal member 50 provided on the outer peripheral surface of the lid 2 is molded from various materials such as thermoplastic elastomers and fluororubbers. The seal member 50 is composed of an endless portion 50a and a lip portion 50b. The endless portion 50a is fitted into a groove formed between the front plate 2a and the back plate 2b, and the lip portion 50b protrudes from the endless portion 50a. The lip portion 50b is molded so that its thickness gradually decreases from its base portion to its tip portion, and its tip portion is molded so that it protrudes obliquely toward the outside toward the inside of the FOUP body 1. When the lid 2 is fitted into the FOUP body 1, the lip portion 50b comes into contact with the internal wall of the FOUP body 1, thereby sealing the internal space of the FOUP body 1. A gap 62 is provided between the integrated lid 2 and FOUP body 1. This gap 62 is provided on the outer periphery of the lid 2, and the gap dimension between the FOUP body 1 and the lid in this embodiment is designated as L2.

[0038] 7, the periphery of the opening 44 of the FOUP body 1 is formed with a first flat surface 57 formed on the opening flange 48 of the FOUP body 1, and a second flat surface 58 formed at a position recessed from the first flat surface 57 and having an area smaller than the first flat surface 57. The first flat surface 57 and the second flat surface 58 are formed in a stepped shape, and an inclined surface 59a is formed between the first flat surface 57 and the second flat surface 58 so that the opening area gradually increases from the inside of the FOUP 30 to the outside. The lid 2 is formed with an inclined surface 59b corresponding to the outward inclined surface 59a, and these inclined surfaces 59a, 59b function as guides for smoothly fitting the lid 2 to the FOUP body 1 when the lid 2 and the FOUP body 1 are fitted together.

[0039] In addition, a biasing mechanism is provided inside the lid 2, which biases the lid 2 in a direction pressing it against the FOUP body 1 when the lid 2 is locked. FIG. 8 is a partially enlarged cross-sectional view showing the structure of the biasing mechanism, and shows a state in which the locking member 55 enters or retreats into the recess 49 of the opening flange 48 when the lid 2 is locked or unlocked. FIG. 8(a) shows a state in which the lid 2 and the FOUP body 1 are not locked and the lip portion 50b of the seal member 50 is in contact with the second flat surface 58 of the FOUP body 1. When the latch key 15 rotates and the locking member 55 moves from a state in which it is recessed into the lid 2 to a position in which it protrudes from the lid 2 and enters the recess 49, the protrusion portion 60a provided on the locking member 55 comes into contact with the protrusion portion 60b provided on the back plate 2b, and the tip of the locking member 55 is biased in a direction away from the FOUP body 1 (see FIG. 8(b)). Furthermore, when the locking member 55 protrudes from the lid 2, the tip of the locking member 55 comes into contact with the wall surface of the recess 49 of the FOUP body 1, and the lid 2 is urged in a direction in which it is pushed inward into the FOUP body 1 (see FIG. 8(c)). This urging force presses the lid 2 toward the back of the FOUP body 1, and the lip portion 50b of the sealing member 50 is also pressed toward the second flat surface 58 of the FOUP body 1, and the lip portion 50b is deformed and comes into close contact with the second flat surface 58. This seals the internal space of the FOUP 30.

[0040] The seal member 50 is made of a flexible material such as fluororubber or silicone rubber, and once the FOUP body 1 and the lid 2 are locked, the lip portion 50b of the seal member 50 may adhere to the second flat surface 58 of the FOUP body 1. Furthermore, if there is variation in the processing accuracy of the seal member 50, the lip portion 50b may come into contact with the peripheral wall of the second flat surface 58, making it impossible to smoothly open the lid 2 of the FOUP 30, and causing a problem in which the load port 8 malfunctions. Furthermore, the FOUP 30 is often used for a long period of time, and the seal member 50 may deteriorate or the FOUP body 1 may become deformed due to long-term use. Such deterioration of the seal member 50 and deformation of the FOUP body 1 may become a resistance during the door opening operation, and if the lid 2 is forcibly opened, this may cause problems such as the FOUP body 1 floating up. When such a problem occurs, it is necessary to collect the FOUP 30 with the problem, replace the seal member 50, and perform maintenance on the FOUP body 1.

[0041] 10 is a side view for explaining an abnormal operation state of the FOUP 30 when the load port 8 opens the FOUP 30 with the seal member 50 in contact with the second flat surface 58. First, as shown in FIG. 10(a), the stage 21 of the load port 8 on which the FOUP 30 is placed is advanced toward the load port door 28 to bring the lid 2 into contact with the load port door 28. In the load port 8 of this embodiment, the position of the stage 21 and the load port door 28 where the lid 2 and the load port door 28 are integrated is set as the docking position. When the stage 21 is in this docking position, the airflow adjustment member 61 arranged on the periphery of the load port door 28 and the opening flange 48 on the periphery of the FOUP 30 are not in contact with each other, but are positioned facing each other with a predetermined gap 63 in the horizontal direction.

[0042] Next, after the load port door 28 and the lid 2 are integrated and the lid 2 is unlocked, the stage 21 moves backward from the docking position shown in Fig. 10(a) to remove the lid 2 from the FOUP body 1. Here, the position at which the FOUP body 1 and the lid 2 are recognized as being completely separated when they have been properly separated is called the undocking position. Even if the FOUP 1 has the lip portion 50b adhered to the second plane 58, as long as the lip portion 50b is separated from the second plane 58 by the time the FOUP 1 reaches the undocking position, it will not be detected as a placement abnormality.

[0043] When the lid 2 is properly separated by this movement to the undocking position, the stage 21 continues to retreat and moves to the retracted position. When the lid 2 is removed, the transfer robot 9 inserts its fingers into the FOUP body 1 to remove the wafer W contained in the FOUP body 1. The lid 2 and the load port door 28 are lowered to positions where they do not interfere with the operation of the fingers at this time. The retracted position of the stage 21 is a position where they do not interfere with the downward movement of the lid 2 and the load port door 28.

[0044] When the stage 21 moves backward to the undocking position, even though the FOUP body 1 has moved to the undocking position, the lip portion 50b of the seal member 50 may not be separated from the second plane 58, and the lid 2 and the FOUP body 1 may not be separated smoothly. In this case, the flange 48 of the FOUP body 1 sticks to the lid 2 and cannot move backward, so that the FOUP body 1 is in a position tilted forward with the two front kinematic pins 12-1 and 12-2 as fulcrums, as shown in Fig. 10(b). In other words, the rear part of the FOUP body 1 is in a position lifted off the kinematic pin 12-3 arranged behind the stage 21.

[0045] When the rear part of the FOUP body 1 is lifted up, the detection sensor 36-3 arranged near the kinematic pin 12-3 outputs an ON signal. When the ON signal is received from the detection sensor 36-3 at this timing, the load port control unit 35 recognizes that an error has occurred during the door opening operation and transmits an error occurrence signal to the control device 17 of the EFEM 7. When the FOUP body 1 is tilted in this way, the opening flange 48 of the FOUP body 1 and the airflow adjustment member 61 come into contact with each other (see FIG. 10(b)), and there is a risk of a problem in which dust generated at the time of the contact adheres to the wafer W contained in the FOUP body 1. In addition, when the rear part of the FOUP body 1 is in a lifted position, the lip part 50b may separate from the second plane 58, causing the rear part of the FOUP body 1 to fall onto the kinematic pin 12-3, and the wafer W contained in the FOUP 1 may be damaged by the impact. Therefore, if such a problem occurs frequently, the control device 17 will stop the transfer operation of the EFEM 7. It should be noted that such troubles can also occur in a load port 8 in which the lid 2 is removed from the FOUP body 1 by moving the load port door 28 and the lid 2 back relative to the FOUP body 1, without moving the stage 21 back.

[0046] The above-mentioned trouble occurs when the time it takes for the stage 21 to move from the docking position to the undocking position is shorter than the time it takes for the adhered lip portion 50b to separate from the second plane 58. Since the lip portion 50b is a member formed of a flexible material, even when the stage 21 retreats to the undocking position, a part of the lip portion 50b remains adhered to the second plane 58, and the adhered lip portion 50b gradually peels off from the second plane 58, delaying the separation of the lid 2. In the load port 8 of this embodiment, when the detection sensor 36-3 detects that the rear part of the FOUP body 1 has lifted up, the load port control unit 35, which has received the signal, executes an operation of temporarily returning the stage 21 to the docking position and returning the FOUP body 1 to its original normal placement state (the state of FIG. 10(a)). Thereafter, an operation is executed to separate the FOUP body 1 from the lid 2 while preventing the FOUP body 1 from lifting up, such as, for example, retreating the stage 21 using a second operation procedure with an operation speed slower than the normal operation speed.

[0047] From the viewpoint of not decreasing the transport throughput of the entire EFEM7, it is desirable to perform the door-opening operation according to the first operation procedure, which is a normal operation procedure, when no placement abnormality such as the FOUP 30 floating occurs, and to perform the door-opening operation according to the second operation procedure only when a placement abnormality occurs. Also, when a placement abnormality occurs, it is desirable to move the stage 21 back to the undocking position according to the second operation procedure to ensure that the FOUP body 1 and the lid 2 are separated, and after successful separation, to move the stage 21 to the evacuation position according to the fast normal first operation procedure. This makes it possible to suppress a decrease in the throughput of the entire door-opening operation.

[0048] Furthermore, when the control device 17 receives a floating error signal of the FOUP 30 from the load port control unit 35, it transmits an alarm signal (error signal) and ID information of the FOUP 30 to a host computer that manages the wafer processing process in the clean room. The error signal transmitted to the host computer is conveyed to an operator in the clean room, and the operator can repair the FOUP 30 where the problem occurred, thereby preventing the trouble from recurring.

[0049] 9 is a cross-sectional view showing the detection sensor 36-3. The detection sensor 36-3 includes a detection pin 66, a compression coil spring 67 for biasing the detection pin 66 upward, a transmitted light sensor 68, and a housing 69 fixed on the stage 21 and accommodating the detection pin 66 and the compression coil spring 67. When the FOUP 30 is correctly placed on the kinematic pins 12-1, 12-2, and 12-3, as shown in FIG. 9(a), the compression coil spring 67 is compressed by the load of the FOUP 30, and the detection pin 66 is pushed downward by the FOUP 30, blocking the detection light 70 emitted from the light projecting unit 71 of the transmitted light sensor 68. As a result, the light receiving unit 72 does not sense the detection light 70, and the detection sensor 63-3 outputs an OFF signal. The OFF signals from the detection sensors 36-1, 36-2, 36-3 are sent to the load port control unit 35, and the load port control unit 35 recognizes that the FOUP 30 is correctly placed when the OFF signals are sent from all the detection sensors.

[0050] When the rear part of the FOUP 30 is raised, the detection pin 66 is biased upward by the compression coil spring 67, as shown in FIG. 9(b). At this time, the detection light 70 irradiated from the light projector of the transmitted light sensor 68 reaches the light receiver 72, the transmitted light sensor 68 enters a light receiving state, and the detection sensor outputs an ON signal. This ON signal is sent to the load port control unit 35, and the load port control unit 35 recognizes that the FOUP 30 is not placed or is not placed correctly. The vertical dimension and movable range of the detection pin 66 are preferably configured such that the compression coil spring 67 receives the load of the rear part of the FOUP 30 and supports the bottom surface even when the bottom surface of the FOUP 30 is raised. Since the compression coil spring 67 receives the load of the FOUP 30 even when the rear part of the FOUP 30 is raised, the speed at which the rear part of the FOUP 30 falls can be reduced, and the impact caused by the fall can be mitigated. It is preferable that the compression coil spring 67 provided in the detection sensor 36-3 of this embodiment has an elastic force sufficient to enable the detection pin 66 to block the detection light 70 of the transmitted light sensor 68 even when a FOUP body 1 not containing any wafer W is placed on it.

[0051] 3, a detection sensor 65 may be added as a means for detecting that the FOUP body 1 has been lifted, in addition to the detection sensor 36-3 disposed near the kinematic pin 12-3. The detection sensor 65 may be, for example, a proximity sensor, a photosensor, or a photoelectric sensor. The detection sensor 65 may be a sensor of any detection type, but it is preferable to use a sensor with higher detection accuracy than the detection sensor 36-3. For example, if the detection sensor 36-3 detects a placement abnormality when the rear part of the FOUP body 1 is lifted by 2 mm, the detection sensor 65 can be made to be capable of detecting a lift amount smaller than 2 mm, thereby enabling the lifting of the FOUP body 1 to be detected with high accuracy.

[0052] FIG. 11(a) is a graph showing, by a solid line, the elapsed time and the moving distance when the stage 21 is moved from the docking position to the undocking position in a first operation procedure in a state where the lid is difficult to separate from the main body due to adhesion of the sealing member. FIG. 11(b) is a graph showing, by a solid line, the elapsed time and the moving distance when the stage 21 is moved from the docking position to the undocking position in a second operation procedure with a moving speed slower than that of the first operation procedure in a similar state where the lid is difficult to separate. In both graphs, the horizontal axis is time and the vertical axis is the moving distance, and the moving distance is represented by the number of operating pulses of the motor 31. In the motor 31 of this embodiment, as an example, when the stage 21 is at the docking position, it is set to 0 pulses, and when the rotating shaft of the motor 31 is rotated forward to move from the docking position to the undocking position, the number of pulses of the motor 31 is set to 10,000 pulses. Furthermore, the points on the graph indicate the time TX when the lip portion 50b separates from the second plane 58, T1 indicates the time when the stage 21 moves to the undocking position (10,000 pulse position) in the first operating procedure, and T2 indicates the time when the stage 21 moves to the undocking position (10,000 pulse position) in the second operating procedure.

[0053] In Fig. 11(a), in the first operation procedure, which is a normal door-opening operation, the lip portion 50b is not separated from the second plane 58 even when the stage 21 has finished moving to the undocking position, and the rear portion of the FOUP body 1 is in a lifted position, resulting in an error. In contrast, in the second operation procedure, which moves at a slower speed than the first operation procedure as shown in Fig. 11(b), the lip portion 50b is separated from the second plane 58 before the stage 21 moves to the undocking position, so the rear portion of the FOUP body 1 does not lift up and no error occurs. This switching from the first operation procedure to the second operation procedure is performed by the load port control unit 35. As shown in Fig. 13, the load port control unit 35 includes a computer that performs various calculations, a storage means that stores various setting data, teaching data, and operation programs, and a communication means that transmits and receives signals between the drive device, various sensors, etc., of the load port 8. When the load port control unit 35 receives signals from the detection sensors 36-1, 36-2, and 36-3, it switches from the first operation procedure to the second operation procedure in accordance with the operation program stored in the storage means, and executes the operation of opening the door of the FOUP 30.

[0054] Also, the door-opening operation in the second operation procedure may be such that, when the load port control unit 35 moves the stage 21 from the docking position to the undocking position, the door-opening operation of the stage 21 is performed by repeating a short distance backward movement and stopping to move the stage 21 to the undocking position. For example, as shown in FIG. 11(c), if the number of operating pulses of the motor 31 that moves the stage 21 to the undocking position is 10,000 pulses, the rotation shaft of the motor 31 is rotated forward 2,000 pulses to move the stage 21 backward, the rotation shaft of the motor 31 is stopped once, and the rotation shaft of the motor 31 is rotated forward again 2,000 pulses. This operation is repeated until the stage 21 has finished moving to the undocking position at time T3. By performing this operation, the lip portion 50b is separated from the second plane 58 at a time earlier than the stage 21 moves to the undocking position. This prevents the FOUP body 1 from floating up. As shown in Figures 11(b) and (c), in order to suppress a decrease in throughput of the entire door-opening operation, the stage 21 may be moved back to the undocking position at the second operating speed, and thereafter the stage 21 may be moved at the first operating speed, which is faster.

[0055] Furthermore, the load port 8 of this embodiment can also perform door-opening operations other than the door-opening operation described above. In another embodiment of the second operation procedure, when the stage 21 is moved back from the docking position to the undocking position, the stage 21 may be moved back to a predetermined position, then moved forward once, and then moved back again, repeating this operation to move the stage 21 to the undocking position. This operation is performed by sequentially switching the rotation direction and rotation angle of the rotation shaft of the motor 31 of the stage drive unit 23 provided in the load port 8.

[0056] 12(a), if the number of operating pulses of motor 31 required to move stage 21 from the docking position to the undocking position is 10,000 pulses, then the rotating shaft of motor 31 is rotated forward for 3,000 pulses to move stage 21 backward, and then the rotating shaft of motor 31 is rotated reversely for 1,000 pulses to move stage 21 forward. As a result, stage 21 moves to a position 2,000 pulses backward from the docking position. This operation is repeated until time T4 when stage 21 moves to the undocking position, thereby separating lid 2 and FOUP body 1.

[0057] By the above-mentioned various operations, the adhered lip portion 50b is gradually peeled off from the second plane 58, and the lid 2 and the FOUP body 1 can be separated while preventing the FOUP body 1 from floating up. In order to suppress a decrease in the throughput of the entire door-opening operation, the operation speed at which the stage 21 moves back by 3000 pulses and the operation speed at which the stage 21 moves forward by 1000 pulses may be set to an operation speed faster than that in the first operation procedure. In addition, the speed data and teaching data of the motor used in this door-opening operation, and the operation program are stored in the load port control unit 35 provided in the load port 8, and the load port control unit 35 executes this door-opening operation in accordance with the stored operation program. In addition, the above-mentioned numerical values ​​and amounts such as the distance at which the lid 2 is pressed against the flange 48 and the movement amount (number of pulses) of the stage 21 in the first operation procedure and the second operation procedure are merely examples, and can be appropriately adjusted depending on the type of FOUP 30 and the configuration of the stage driving unit 23.

[0058] In another embodiment of the second operation procedure, the FOUP body 1 and the lid 2 can be separated by retracting the stage 21 while vibrating the load port door 28 in the up-down direction (vertical direction). In the load port 8 of this embodiment, airflow adjustment members 61 are arranged above and on the left and right sides of the load port door 28, and a predetermined gap 64 is provided between the load port door 28 and the airflow adjustment members 61 (see FIGS. 2, 4, and 8). Here, assuming that the dimension of the gap 64 is L1, the load port door 28 is vibrated within an operating range smaller than the dimension L1 of the gap 64 above the load port door 28. The airflow adjustment members 61 are arranged in a direction recessed from the surface of the load port door 28 that comes into contact with the lid 2, that is, toward the internal space of the EFEM 7. Therefore, even when the stage 21 moves forward and the load port door 28 and the lid 2 are integrated, the FOUP body 1 and the airflow adjustment member 61 do not come into contact with each other, and even if the load port door 28 vibrates in the vertical direction, the FOUP body 1 and the airflow adjustment member 61 do not rub against each other, causing dust to be generated.

[0059] The vibration operation of the load port door 28 is performed by sequentially switching the rotation direction and rotation angle of the rotation shaft of the motor 33, which is the drive source of the door lifting unit 29, to lift and lower the load port door 28 after the load port door 28 and the lid 2 are integrated together, until the stage 21 moves to the undocking position. FIG. 12(b) is a graph showing the lifting and lowering operation of the load port door 28 while the stage 21 moves from the docking position to the undocking position. The horizontal axis of the graph is the elapsed time, and the vertical axis is the number of operating pulses of the motor 33 of the door lifting unit 29, which represents the moving distance of the load port door 28, and the number of pulses is set to 0 when the load port door 28 is at the docking position where it is integrated with the lid 2. The vertical dashed line T1 on the graph indicates the time when the stage 21 has finished moving to the undocking position, and the point on the graph indicates the time TX when the lip portion 50b is separated from the second plane 58.

[0060] In the load port 8 of this embodiment, if the load port door 28 is moved upward for 5000 pulses, there is a risk that the load port door 28 may come into contact with the airflow adjustment member 61, so the upper limit of the operating range of the load port door 28 is limited to about 4000 pulses. When vibrating the load port door 28, the rotary shaft of the motor 33 is rotated forward for 4000 pulses to move the load port door 28 upward, and then the rotary shaft of the motor 33 is rotated reversely for 4000 pulses to move the load port door 28 downward and return it to the original docking position (number of pulses is 0). This vertical movement of the load port door 28 also causes the lid 2 integrated with the load port door 28 to repeatedly move upward and downward relative to the FOUP body 1, and the FOUP body 1 and the lid 2 are separated by peeling off the adhered lip portion 50b from the second plane 58. It is preferable that the vertical movement of the load port door 28 continues until the stage 21 moves to the undocking position. In addition, by moving the stage 21 back to the undocking position using the second operating procedure, and then moving the stage 21 using the first operating procedure, which has a faster operating speed, it is possible to suppress a decrease in throughput of the entire door-opening operation.

[0061] The above-mentioned number of operation pulses and the number of lifting and lowering operations are merely examples, and it is preferable to adjust them appropriately according to the type of FOUP 30 and the configuration of the load port 8. In the above embodiment, the load port door 28 is set to be lifted and lowered while the stage 21 is moving from the docking position to the undocking position, but the present invention is not limited to this. When the load port door 28 and the lid 2 are integrated and the lid 2 is unlocked, the load port door 28 may be lifted and lowered before the stage 21 starts moving to the undocking position, and the stage 21 may start moving to the undocking position after the load port door 28 has been lifted and lowered. By vibrating the load port door 28 and the lid 2, dust may be generated around the latch key 15 that integrates the load port door 28 and the lid 2. However, since the load port door 28 and the lid 2 are in close contact with each other, the generated dust does not scatter to the outside from the joint. Furthermore, even if dust were to fly to the outside through the gap between the load port door 28 and the lid 2, the dust would be discharged to the outside of the EFEM 7 by the downflow from the FFU 10, and would not adhere to the surfaces of the wafers W housed in the FOUP body 1.

[0062] Furthermore, as another embodiment of the lifting and lowering operation performed by the load port 8, the lifting and lowering operation range of the load port door 28 can also be expanded below the docking position (0 pulse) where the load port door 28 is integrated with the lid 2. FIG. 12(c) is a graph showing the expanded lifting and lowering operation of the load port door 28. As with FIG. 12(b), the horizontal axis of the graph represents time, and the vertical axis represents the movement distance of the load port door 28 represented by the number of operating pulses of the motor 33 of the door lifting and lowering section 29. In this embodiment, in addition to the operation of moving the load port door 28 above the position where it is integrated with the lid 2 (in the positive direction), the load port door 28 is also moved below the position where it is integrated with the lid 2 (in the negative direction).

[0063] After the load port door 2 and the lid 2 are integrated, the rotary shaft of the motor 33 is rotated forward for 4000 pulses to move the load port door 28 upward by 4000 pulses, and then the rotary shaft of the motor 33 is rotated backward for 8000 pulses to move the load port door 28 downward by 8000 pulses to move the load port door 28 to a position 4000 pulses lowered from the docking position (pulse number 0). Next, the rotary shaft of the motor 33 is rotated forward for 8000 pulses to move the load port door 28 to a position 4000 pulses higher from the docking position. This vertical movement of the load port door 28 causes the lid 2 to repeatedly move upward and downward relative to the FOUP body 1, and the adhered lip portion 50b is peeled off from the second plane 58, making it easier to separate the FOUP body 1 and the lid 2. It is preferable that the vertical movement of the load port door 28 continues until the stage 21 moves to the undocking position. In addition, by moving the stage 21 back to the undocking position using the second operating procedure, and then moving the stage 21 using the first operating procedure, which has a faster operating speed, it is possible to suppress a decrease in throughput of the entire door-opening operation.

[0064] As described above, in this embodiment, the vibration range of the load port door 28 is large, so that the adhered lip portion 50b can be quickly separated from the second plane 58. It is desirable to suppress the downward movement of the load port door 28 when vibrating to a degree that does not cause the rear end of the FOUP 30 to lift up. In addition, in the above two embodiments in which the load port door 28 is vibrated, the movement range when the load port door 28 is moved up and down is described based on the dimension L1 of the gap 63 between the load port door 28 and the airflow adjustment member 61. However, if the dimension L2 of the gap 62 between the FOUP body 1 and the lid 2 is smaller than the dimension L1, it is desirable to set the lifting range of the load port door 28 to the dimension L2. By lifting and lowering the load port door 28 within a movement range smaller than the dimension L1, it is possible to prevent the FOUP body 1 and the lid 2 from colliding with each other and the rear part of the FOUP body 1 from lifting up.

[0065] It should be noted that the above-mentioned numbers of operating pulses and the number of lifting and lowering operations are merely examples, and it is preferable to adjust them appropriately depending on the type of FOUP 30 and the configuration of the load port 8. Furthermore, the lifting and lowering operation of the load port door 28 may be performed in combination with the operation of the stage 21 moving from the docking position to the undocking position, or the lifting and lowering operation of the load port door 28 may be performed before the stage 21 starts its operation to the undocking position, and after the lifting and lowering operation of the load port door 28 is completed, the stage 21 may start moving to the undocking position.

[0066] In addition, the various other second operation procedures exemplified above can be used in appropriate combination. Furthermore, when the lid cannot be separated even with the second operation procedure, it is also possible to configure to execute various second operation procedures a predetermined number of times. Furthermore, it is also possible to configure to assign an appropriate priority to the second operation procedures, and execute the various different second operation procedures described above in sequence according to the priority order. For example, when the lid cannot be separated from the container body even if the stage is moved at a speed slower than the moving speed of the first operation procedure as the second operation procedure, it is possible to perform an operation in which the movement of the stage is divided as a third operation procedure and the movement and stopping are repeated intermittently. Furthermore, it is also possible to assign an order of priority to the operation procedures described above as the second operation procedure, and to configure to execute them in combination as the third and fourth operation procedures.

[0067] The above describes in detail an embodiment of the present invention with reference to the drawings, but the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the present invention.

Claims

1. a stage for mounting, at a predetermined position, a sealed container having a container body for accommodating a wafer and a lid for airtightly closing the container body; a sensor for detecting a state in which the sealed container is placed on the stage; a stage driving mechanism that moves the stage back and forth at least between a docking position and an undocking position; a load port door which is joined to the lid to form an integrated body and then separates the lid from the container body to open the sealed container; a door lifting mechanism for lifting and lowering the load port door; a load port control unit that stores a plurality of operation procedures for operating the stage drive mechanism, the load port door, and the door lifting mechanism, and controls the operations of the stage drive mechanism, the load port door, and the door lifting mechanism based on the operation procedures, The load port control unit includes: in order to separate the lid from the container body and open the sealed container, based on a first operation procedure, controlling the stage drive mechanism and the door lifting mechanism to move the stage back to the undocking position at a first speed from a state in which the load port door and the lid are joined and integrated at the docking position; When the sensor detects an abnormality in placement of the sealed container during the door opening operation according to the first operation procedure, the sealed container is returned to the docking position, and then the door opening operation is controlled to be re-executed based on a second operation procedure different from the first operation procedure. A load port characterized by:

2. 2. The load port according to claim 1, wherein the second operation procedure controls the stage drive mechanism to retract from the docking position at a speed slower than the first speed.

3. the second operation procedure is an operation procedure in which the distance from the docking position to the undocking position is divided into a plurality of parts, and the stage is moved backward from the docking position to the undocking position while temporarily stopping at each of the divided distances. The load port according to claim 1.

4. 2. The load port according to claim 1, wherein the second operation procedure is an operation procedure in which a distance from the docking position to the undocking position is divided into a plurality of parts, and the stage is moved from the docking position to the undocking position by repeatedly moving the stage forward and backward for each of the divided distances.

5. An airflow adjustment member is disposed above and on the left and right edges of the load port door with a gap of a predetermined dimension therebetween, 5. The load port according to claim 1, wherein the second operation procedure comprises moving the stage from the docking position to the undocking position by the stage driving mechanism while the door lifting mechanism lifts and lowers the load port door, which is integrated with the lid, in the vertical direction within a range smaller than the specified gap dimension.

6. 6. The load port according to claim 1, wherein the load port control unit controls the second operation procedure to be repeatedly executed a predetermined number of times if the sensor detects an abnormality in the placement of the sealed container again when the second operation procedure is executed.

7. The load port control unit includes:

3. The load port according to claim 2, further comprising: a control unit for controlling the stage drive mechanism to move backward from the docking position at a speed slower than the first speed; and if the sensor again detects an abnormality in the placement of the sealed container when the door-opening operation is performed according to the second operation procedure, the control unit controls the stage drive mechanism to move backward from the docking position at a speed slower than the first speed, so that after the sealed container is returned to the docking position, the door-opening operation is re-executed based on a third operation procedure different from the first and second operation procedures.

8. The load port control unit includes:

4. The load port according to claim 3, wherein when the door-opening operation is performed according to the second operation procedure in which a distance from the docking position to the undocking position is divided into a plurality of parts and the stage is retracted from the docking position to the undocking position while temporarily stopping at each of the divided distances, if the sensor again detects an abnormality in the placement of the sealed container, the sealed container is returned to the docking position again and then the door-opening operation is controlled to be re-executed based on a third operation procedure different from the first and second operation procedures.

9. The load port control unit includes:

5. The load port according to claim 4, wherein when the door-opening operation is performed according to the second operation procedure in which a distance from the docking position to the undocking position is divided into a plurality of parts and the stage is repeatedly advanced and retreated for each of the divided distances to move the stage from the docking position to the undocking position, if the sensor again detects an abnormality in the placement of the sealed container, the door-opening operation is controlled so that the sealed container is returned to the docking position again and then the door-opening operation is re-executed based on a third operation procedure different from the first and second operation procedures.

10. An airflow adjustment member is disposed above and on the left and right edges of the load port door with a gap of a predetermined dimension therebetween, When the door opening operation according to the second operation procedure is executed in which the stage is moved from the docking position to the undocking position by the stage driving mechanism while the load port door integrated with the lid is vertically raised and lowered by the door lifting mechanism within a range smaller than the predetermined gap dimension, the sensor detects the placement abnormality of the sealed container again. The load port according to claim 4, characterized in that, when detected, the sealed container is returned to the docking position again, and then the door opening operation is controlled to be re-executed based on a third operating procedure different from the first and second operating procedures.

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