Loading Port

Abstract

To provide a loading port and a mapping processing method for the loading port that can accurately and precisely detect the storage state of an object to be transported in a storage vessel, even when the object is large and has a rectangular planar shape, without increasing the size of the entire apparatus.SOLUTION: As a mapping mechanism M that maps information regarding the storage state including the presence or absence of an object W to be transported supported in the corresponding slots at both side portions and the widthwise central portion in each stage of the slots 34 in a storage container 3, a mechanism is applied that has three or more mapping sensors M1, M2, M3 supported by a mapping arm M4 and capable of detecting the end surface Wa of the transport object W without photographing or image processing, and a discrimination unit M5 that discriminates whether the storage state of the transport object W is good or bad based on the sensing information from these three or more mapping sensors M1, M2, M3.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a load port used in semiconductor manufacturing processes to transfer objects to and from a FOUP, which is a storage container capable of storing multiple objects such as wafers in multi-stage slots, and in particular to a load port equipped with a mapping mechanism that maps information regarding the status of each slot of the FOUP, including the presence or absence of an object, and a mapping processing method for the load port. [Background technology]

[0002] For example, in semiconductor manufacturing processes, wafers are processed in clean rooms to improve yield and quality. In recent years, a "mini-environment system" has been adopted, which further improves the cleanliness of only the localized space around the wafer, and is used to transport and perform other processing on the wafer. In the mini-environment system, a load port is provided adjacent to the wafer transport chamber (hereinafter referred to as the transport chamber), forming part of the wall of the wafer transport chamber (hereinafter referred to as the transport chamber), which is a nearly enclosed enclosure. A FOUP (Front-Opening Unified Pod), a container that contains wafers and other transport objects, is placed in the highly clean interior space. The load port is capable of opening and closing the FOUP door while fitting tightly against the FOUP door. Hereinafter, the load port door that can engage with the FOUP door and open and close the FOUP door will be referred to as the "load port door."

[0003] Such a load port is a device for transferring objects into and out of the transfer chamber, and functions as an interface between the transfer chamber and the FOUP. When the FOUP door and the load port door are opened simultaneously with the load port door tightly attached to the FOUP door, a transfer robot located inside the transfer chamber can remove objects from the FOUP into the transfer chamber or store objects from the transfer chamber into the FOUP.

[0004] The load port is equipped with a mapping mechanism that can detect the presence or absence of transport objects and their storage orientation in the multi-stage slots provided within the FOUP. Conventional mapping mechanisms assume that the transport objects are circular, and perform mapping processing to detect the presence or absence of transport objects in each slot using a transmission-type optical sensor with a sensing line (light-receiving line) that crosses the tip of the transport object that is closer to the FOUP door than the center in the depth direction of the transport object (part of the outer edge (circumference) of the circle).

[0005] One example of a mapping mechanism is one in which a mapper equipped with a mapping sensor at its tip is configured to move between a non-mapping position, where the mapper is retracted toward the transfer chamber from the load port frame, and a mapping position, where the mapper is closer to the FOUP than the non-mapping position, through an opening in the frame. The mapping mechanism also includes a mapping movement unit (mapping arm) that supports the mapper. By moving the mapping arm vertically while maintaining the mapper in the mapping position, the mechanism is able to detect whether or not an object is contained in each of the multi-stage slots (presence / absence detection). Furthermore, the mechanism also simultaneously detects cross-loading, where objects are supported in slots at different heights (cross detection), and double-loading, where two objects are supported overlapping each other in the same slot (double detection). The mapping arm moves up and down either integrally with or independently of the load port door.

[0006] However, although the mapping process by the above-described mapping mechanism can be performed smoothly and appropriately if the transported object is circular, it cannot be performed if the transported object has a shape other than circular, such as a rectangular panel or wafer.

[0007] In other words, with conventional mapping mechanisms, a mapper equipped with a mapping sensor (e.g., a transmission-type optical sensor equipped with a light emitting unit and a light receiving unit) must be inserted into the FOUP during mapping processing, and the light emitting unit and the light receiving unit must be positioned so that they can reliably sandwich the outer periphery of the object being transported from a substantially horizontal direction. If the object is circular, it is possible to ensure a space between the outer periphery of the object and the inner surface of the FOUP on the FOUP door side. However, if the object is a so-called rectangular glass substrate, such as a square or rectangular object, the area occupied by the object in the FOUP is larger than in a circular object, making it impossible or extremely difficult to ensure a space between the outer periphery of the object and the inner surface of the FOUP for the sensor of the mapping mechanism to sufficiently enter.

[0008] Meanwhile, Patent Document 1 proposes a load port equipped with a mapping mechanism having a light-emitting unit that irradiates light for imaging toward the transport object, and an imaging unit that captures an image by imaging within an illumination area illuminated by the light emitted from the light-emitting unit. Specifically, Patent Document 1 discloses a configuration in which one imaging unit is provided in correspondence with one light-emitting unit that irradiates light so that only one transport object is included within the illumination area, the light-emitting unit irradiates light for imaging toward the transport object, and the imaging unit captures an image by imaging within the illumination area illuminated by the light-emitting unit, thereby making it possible to grasp the storage status of even rectangular transport objects based on the captured image. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2019-102753 Summary of the Invention [Problem to be solved by the invention]

[0010] However, with the above-mentioned mapping mechanism, which irradiates light so that only one transport object is included within the illumination area, as the size of the rectangular transport object increases, the illumination area that occupies the entire transport object becomes smaller, and it may not be possible to perform accurate cross detection with just one captured image of one transport object. For example, when a configuration is adopted in which a large object to be transported within a FOUP is supported by support portions such as slots provided in three locations, on the left, right, and center, within the FOUP, it may not be possible to accurately detect the following three patterns of abnormal cross loading using only a single captured image: i) abnormal cross loading, in which the right and center are supported by support portions at the same height, and only the left is not supported by a support portion at the same height as the right and center (either supported by a support portion at a different height from the right and center, or supported by none of the support portions); ii) abnormal cross loading, in which the left and center are supported by support portions at the same height, and only the right is not supported by a support portion at the same height as the left and center (supported by a support portion at a different height from the left and center, or supported by none of the support portions); and iii) abnormal cross loading, in which the left and right are supported by support portions at the same height, and only the center is not supported by a support portion at the same height as the left and right (supported by a support portion at a different height from the left and right, or supported by none of the support portions). In particular, if the object to be transported is large and thin, it is expected that the object will be stored in a sagging state due to its own weight as well as its thinness. Such sagging loading, in which the object is stored in a sagging state, can be considered to be one form of abnormal cross loading.

[0011] Furthermore, the mapping mechanism described in Patent Document 1 requires a process of capturing an image of the inside of an illumination area illuminated by light from the light-emitting unit to obtain the captured image, and a process of identifying the storage state of the transported object based on the captured image. Compared to mapping mechanisms that can identify the storage state of the transported object by detecting a light-receiving state or a light-blocking state, this requires more advanced processing and results in a longer takt time.

[0012] Patent Document 1 discloses an embodiment in which two mapping sensors are provided, each configured to capture an image of a different field of view of the transport object, and the storage state is determined based on the captured image acquired by one mapping sensor and the other based on the captured image acquired by the other mapping sensor. In this case, if the determinations of the storage state based on the two captured images are both "good," the storage state of the transport object can be determined to be "good," and if the determination of the storage state based on either captured image is "poor," the storage state of the transport object can be determined to be "poor." However, as the number of captured images increases, more time is required for image processing and determination, and the number of light-emitting units and image-capturing units also increases, making the equipment cost very high.

[0013] The present invention has been made in light of these problems, and a primary object of the present invention is to provide a load port and a mapping processing method for a load port that are capable of accurately and precisely detecting the storage state within a containment vessel, even for large objects to be transported that have a rectangular planar shape, without increasing the size of the entire equipment. [Means for solving the problem]

[0014] That is, the present invention provides a load port comprising: a flat frame arranged in an upright position and having an opening through which an object to be transported can pass in a substantially horizontal position; a load port door that can engage with a container door that can open and close an entrance for an object to be transported of a storage container having slots that can accommodate a plurality of objects to be transported in multiple tiers and that can open and close the opening of the frame; a mapping mechanism that maps information about the storage status including the presence or absence of an object to be transported in the slots of each tier within the storage container through the open opening and entrance, wherein each tier of slots has two slots that support both side portions of the object to be transported at the same height position and a slot that supports the central portion of the object in the width direction at the same height position as these two slots; the mapping mechanism comprises a mapping arm that moves up and down integrally with or independently of the lifting and lowering movement of the load port door when opening and closing the opening; three or more mapping sensors that are supported by the mapping arm and can detect the edge face of the object to be transported without photographing or image processing; and a discrimination unit that discriminates whether the storage status of the object to be transported is good or bad based on sensing information from the three or more mapping sensors.

[0015] With this type of load port according to the present invention, it is possible to use the mapping mechanism to map information regarding the storage state, including the presence or absence of an object supported at both side portions and the widthwise center portion in the slots of each stage inside the storage vessel. In particular, because three or more mapping sensors are arranged side by side on a common mapping arm, if, for example, all three or more mapping sensors detect the end face of the object to be transported, the discrimination unit can determine that the object to be transported is stored in a horizontal position based on the sensing information from these three or more mapping sensors. For example, if one mapping sensor detects the end face of the object to be transported and at least one of the other two mapping sensors does not detect the end face of the object to be transported, the discrimination unit can determine that the object to be transported is not stored in a horizontal position but is stored in an oblique position (abnormal cross loading) based on the sensing information from these three or more mapping sensors. Therefore, with the load port according to the present invention, even if the transport object is large and thin and has a rectangular planar shape and a linear end face that spans almost the entire width of the loading / unloading entrance of the storage vessel, the three or more mapping sensors described above can detect the end portions near both ends and the center portion of the end face of the transport object facing the loading / unloading entrance, thereby enabling accurate and precise detection of the storage condition of the transport object within the storage vessel. Furthermore, with the load port according to the present invention, the mapping mechanism can map information about the storage condition, including the presence or absence of the transport object in each slot within the storage vessel, without taking photographs or processing images. This enables faster processing of detecting the transport object and reduces system costs compared to image processing systems using cameras, etc. Here, in the present invention, a preferred example of a configuration in which information about the storage condition, including the presence or absence of the transport object in each slot within the storage vessel, is “mapped without taking photographs or processing images” can be a configuration in which “each mapping sensor having a predetermined detection area detects the end face of the transport object to map (determine whether the storage condition of the transport object is good or bad).”

[0016] Furthermore, in a load port according to the present invention, if the mapping arm is configured to move up and down integrally with the lifting and lowering of the load port door when opening and closing the opening, a mechanism for independently lifting and lowering the mapping arm is not required, and yet the mapping process by the mapping mechanism can be performed at the same time as the opening and closing process, thereby improving the operating rate in semiconductor manufacturing, for example. Note that the load port according to the present invention also includes a configuration in which the mapping arm moves up and down independently of the lifting and lowering of the load port door when opening and closing the opening. In this case, the mapping process by the mapping mechanism can be performed at the same time as the opening and closing process or at a different time.

[0017] In the present invention, it is preferable that the detection target area by a first mapping sensor among the three or more mapping sensors is set to a portion near one end of the loading / unloading entrance of the storage container, the detection target area by a second mapping sensor is set to a portion near the other end of the loading / unloading entrance, and the detection target area by a third mapping sensor is set to a central portion in the width direction of the loading / unloading entrance, and the detection target areas are set so that the sensor light by the first mapping sensor and the second mapping sensor does not irradiate each of the two slots supporting both side portions of the transport object, and the detection target area is set so that the sensor light by the third mapping sensor does not irradiate the slot supporting the central portion in the width direction of the transport object.

[0018] In this case, the mapping sensors are configured to detect the presence or absence of an end face of the object to be transported and the thickness of the end face of the object to be transported based on sensing information from a preset main mapping sensor among the three or more mapping sensors and the number of pulses of a stepping motor that raises and lowers the mapping arm, and the sub-mapping sensor is configured to detect the presence or absence of an end face of the object to be transported, and sensing processing is performed by the remaining two mapping sensors (the mapping sensors among the three or more mapping sensors other than the main mapping sensor) at the same time as the sensing processing by the main mapping sensor. This shortens the processing time required for the discrimination unit to determine whether the object to be transported is properly stored based on the sensing information from the three or more mapping sensors, and with the simplest configuration, can quickly and reliably detect the presence or absence of the object to be transported and abnormal cross loading, which are the detection targets at the time of the sensing processing, as well as whether the object to be transported is stored in a state where multiple objects are stacked (double abnormal loading). Note that it is preferable to set the third mapping sensor, whose detection target area is the center of the loading / unloading entrance in the width direction, as the main mapping sensor, and set the first and second mapping sensors, whose detection target areas are the areas near both ends of the loading / unloading entrance, as the sub-mapping sensors.

[0019] Furthermore, in the present invention, the object to be transported may be a rectangular substrate, in which case each mapping sensor may be set in a direction parallel or approximately parallel to the extension direction of the end face of the object to be transported, and the mapping mechanism may be configured to determine whether the object to be transported is in a good or bad state by detecting the end face of the object to be transported with each mapping sensor having a predetermined detection target area.

[0020] With such a load port, it is possible to accurately and precisely detect the storage state of an object to be transported inside the storage vessel, even if the object is large and rectangular. [Effects of the Invention]

[0021] The present invention employs a novel technical idea of ​​arranging three or more mapping sensors spaced apart horizontally on a common mapping arm, and using these three or more mapping sensors to detect three different locations on the end face of an object to be transported without photography or image processing, thereby avoiding the increase in cost and complexity of the mapping mechanism and not increasing the size of the entire device, and making it possible to provide a load port and a mapping processing method for a load port that are capable of accurately and precisely detecting the storage state within a containment vessel, even for objects that are large and thin and have a rectangular planar shape. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a side view showing a schematic diagram illustrating the relative positional relationship between an EFEM equipped with a load port according to an embodiment of the present invention and its peripheral devices. [Figure 2] FIG. 2 is a simplified plan view of the relative positional relationship shown in FIG. 1. [Figure 3] FIG. 10 is a diagram showing a schematic diagram of the relative positional relationship between the transfer object accommodated in the slot in the storage vessel and the mapping mechanism. [Figure 4] FIG. 2 is a front view showing the load port according to the embodiment with some parts omitted. [Figure 5] FIG. 3 is a diagram schematically showing a detection target area of ​​a mapping sensor in the present embodiment. [Figure 6] 4 is a flowchart showing the operation procedure of the load port in the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0024] The load port 1 according to this embodiment is used, for example, in a semiconductor manufacturing process, and as shown in FIGS. 1 and 2, constitutes part of the wall of a transfer chamber 2 in a clean room, and is used to transfer an object W between the transfer chamber 2 and a storage container 3 such as a FOUP. The object W may be made of a material such as glass, resin, or stainless steel. The load port 1 constitutes part of an EFEM (Equipment Front End Module) and functions as an interface between the storage container 3 and the transfer chamber 2. In this embodiment, a relatively large, thin object W is used (for example, a glass substrate with a planar size of 600 mm × 600 mm or 515 mm × 510 mm and a thickness of 0.2 mm to 2 mm).

[0025] 2, in this embodiment, a plurality of load ports 1 (for example, three) are arranged side by side on the front surface (front wall surface) 2F of the transfer chamber 2. The operation of the EFEM is controlled by a controller of the load port 1 (controller 1C shown in FIG. 1) and a controller for the entire EFEM (controller 2C shown in FIG. 1).

[0026] The internal space 2S of the transfer chamber 2 is provided with a transfer robot 21 capable of transferring a transfer target, such as a glass substrate, between the storage vessel 3 on the load port 1 and the processing chamber R. As shown in FIGS. 1 and 2 , the transfer robot 21 includes, for example, an arm 212 with a transfer target gripper 211 (hand) at its tip, formed by connecting multiple link elements to each other so as to be horizontally rotatable, and a traveling unit that rotatably supports an arm base constituting the base end of the arm 212 and travels in the width direction of the transfer chamber 2 (the parallel direction of the load port 1). The transfer robot 21 has a link structure (multi-joint structure) whose shape changes between a folded state in which the arm length is minimized and an extended state in which the arm length is longer than in the folded state. A transfer robot 21 having multiple individually controllable hands 211 arranged in multiple stages in the height direction at the tip of the arm 212 may also be used. Alternatively, a transfer robot without a traveling unit and fixed in its installation position may be used, or a sacrificial robot may also be used as the transfer robot.

[0027] The transfer chamber 2 is configured so that the internal space 2S is substantially sealed by connecting the load port 1 and the processing chamber R. A downflow, which is an airflow moving from above to below, is formed in the internal space 2S of the transfer chamber 2. Therefore, even if particles that contaminate the surface of the workpiece W are present in the internal space 2S of the transfer chamber 2, the downflow pushes the particles downward, preventing them from adhering to the surface of the workpiece W during transfer. In FIG. 1, the arrows schematically show the flow of gas within the transfer chamber 2 that forms the downflow. It is also possible to configure an EFEM by arranging appropriate stations, such as a buffer station or an aligner, on the side of the transfer chamber 2 or in the internal space 2S of the transfer chamber 2.

[0028] The internal space 2S of the transfer chamber 2 and the internal space 3S of the containment vessel 3 placed on each load port 1 are maintained at a high level of cleanliness. On the other hand, the space in which the load port 1 is located, in other words, the outside of the processing chamber and the outside of the EFEM, has a relatively low level of cleanliness. Figures 1 and 2 are schematic diagrams showing the relative positional relationship between the load port 1 and the transfer chamber 2, and the relative positional relationship between the EFEM equipped with these load ports 1 and the transfer chamber 2 and the processing chamber R.

[0029] As shown in FIG. 1 , the storage container 3 in this embodiment includes a container body 32 that can open the internal space 3S only rearward through a loading / unloading port 31, and a container door 33 that can open and close the loading / unloading port 31. As shown in FIG. 3 , the storage container 3 has multi-stage slots 34 formed therein, each of which can accommodate an object W to be transported. These objects W can be loaded and unloaded through the loading / unloading port 31. In this embodiment, as shown in FIG. 5( a), both side portions of the object W are supported by slots 34a and 34b at the same height within the storage container 3, and a central portion of the object W in the width direction is supported by slots 34c at the same height as slots 34a and 34b. A flange 35 is provided on the upper surface of the container body 32 and can be gripped by a device that automatically transports the storage container 3 (e.g., an overhead transport (OHT)) (see FIG. 1 ).

[0030] 1 and the like, the load port 1 according to this embodiment is equipped with: a plate-shaped frame 4 that constitutes part of the wall of the transfer chamber 2 and has an opening 41 formed therein for opening the internal space 2S of the transfer chamber 2; a loading table 5 that protrudes forward relative to the frame 4 and is positioned in a substantially horizontal position; a seating and holding mechanism 6 that holds a storage container 3 that has been transferred from the outside on the loading table 5; a traction mechanism 7 that moves the storage container 3 on the loading table 5 in the forward and backward directions D between the seating position and the transfer object delivery position; a load port door 8 that opens and closes the opening 41 in the frame 4; a door opening and closing mechanism 9 that moves the load port door 8 to a door open position retracted toward the transfer chamber 2, thereby opening the opening 41 in the frame 4; and a mapping mechanism M that, when the opening 41 in the frame 4 is in the open state by the door opening and closing mechanism 9, maps information about the storage state, including the presence or absence of an object W to be transferred, in each slot 34 (34a, 34b, 34c) in the storage container 3 that is positioned at the transfer object delivery position.

[0031] The frame 4 is arranged in an upright position and is a generally rectangular plate-like structure having an opening 41 large enough to communicate with the loading / unloading entrance of the storage vessel 3 placed on the loading table 5. FIG. 1 shows a schematic diagram of the opening 41 of the frame 4. In the load port 1 of this embodiment, the frame 4 forms part of the wall of the transfer chamber 2. The lower end of the frame 4 is provided with legs 42 having casters and installation legs.

[0032] The loading table 5 is provided on top of a horizontal base 50 (support stand) that is placed in a substantially horizontal position at a position slightly above the center of the frame 4 in the height direction, and is capable of loading the storage vessel 3 with the container body 32 facing the frame 4. As shown in FIG. 4, the loading table 5 is provided with a plurality of protrusions 51 that protrude upward, and these protrusions 51 are engaged with holes (not shown) formed in the bottom surface of the storage vessel 3, thereby positioning the storage vessel 3 on the loading table 5.

[0033] The seating holding mechanism 6 holds the storage container 3 on the loading table 5 by hooking a locking claw 61 (see FIG. 4) provided on the loading table 5 onto a locked portion (not shown) provided on the bottom surface of the storage container 3 to fix it in a locked state. Furthermore, in the load port 1 of this embodiment, the storage container 3 can be made to be able to separate from the loading table 5 by releasing the locked state of the locking claw 61 with respect to the locked portion.

[0034] The traction mechanism 7 moves the storage container 3 on the loading table 5 in the forward and backward direction D between a seating position where the container body 32 is spaced a predetermined distance from the load port door 8, and a transfer position where the container body 32 is in close contact with the load port door 8. The traction mechanism 7 is configured using slide rails (not shown) or the like that move the loading table 5 forward and backward. The seating holding mechanism 6 and the traction mechanism 7 can also be considered as mechanisms that the loading table 5 is equipped with.

[0035] 1, the state in which the containment vessel 3 is placed on the placement table 5 is simply shown as a state in which the bottom surface of the containment vessel 3 is in contact with the top surface of the placement table 5. However, in reality, the containment vessel 3 is supported by a plurality of protrusions 51 that protrude above the top surface of the placement table 5 and engage with bottomed holes formed in the bottom surface of the containment vessel 3, and the top surface of the placement table 5 and the bottom surface of the containment vessel 3 do not come into contact with each other, but a predetermined gap is formed between the top surface of the placement table 5 and the bottom surface of the containment vessel 3.

[0036] In the present invention and this embodiment, in the front-to-rear direction D (see Figure 1, etc.) in which the storage container 3 placed on the mounting table 5 and the frame 4 are aligned, the storage container 3 side is defined as the front, and the frame 4 side is defined as the rear.

[0037] The load port door 8 is movable between a fully closed position, which seals the opening 41 of the frame 4; a door open position, which is retreated toward the transfer chamber 2 from the fully closed position; and a fully open position, which fully opens the opening space of the opening 41 to the rear. Note that in FIG. 1, the load port door 8 is shown in the door open position to schematically illustrate the appearance of the load port door 8 and the mapping mechanism M (described later). However, in actual operation, the load port door 8 is positioned in the door open position when the containment vessel 3 is moved to the transfer object delivery position (a position where the container body 32 is in close contact with the load port door 8) and the container door 33 is engaged and held. In other words, it is essential to operate the load port door 8 in such a way that the interior of the EFEM and the transfer chamber 2 are not exposed to the outside space. The load port door 8 has an engaging portion 81 that can suction and hold the container door 33 of the containment vessel 3 (see FIG. 4). The load port door 8 is configured to be movable integrally with the container door 33 between the fully closed position, the door open position, and the fully open position while maintaining the engaged state with the container door 33. The movement path of the load port door 8 between the fully closed position and the fully open position consists of a path (horizontal path) in which the load port door 8 in the fully closed position is moved toward the transfer chamber 2 to the door open position while maintaining its height position, and a path (vertical path) in which the load port door 8 in the door open position is moved downward to the fully open position while maintaining its front-to-back position. To allow the load port door 8 positioned in the door open position to move both vertically and horizontally, the container door 33 held by the load port door 8 positioned in the door open position is positioned together with the load port door 8 at a position rearward of the frame 4 (a position completely separated from the container body 32 and located in the internal space 2S of the transfer chamber 2).

[0038] Such movement of the load port door 8 is achieved by a door opening / closing mechanism 9 provided on the load port 1. The door opening / closing mechanism 9 moves the load port door 8 to the door open position or the fully open position, thereby connecting the internal space 3S of the storage vessel 3 to the transfer chamber 2 through the opening of the frame 4 when it is in the open state. The door opening / closing mechanism 9 is configured using, for example, a movable block (not shown) that supports the support frame 80 that supports the load port door 8 so that it can move in the forward / backward direction D, and a slide rail (not shown) that supports the movable block so that it can move in the up / down direction H, and operates a drive source (not shown) such as an actuator to move the load port door 8 in the forward / backward direction D and the up / down direction H. Note that while a configuration in which separate actuators for forward / backward movement and up / down movement are provided may be used, a configuration in which a common actuator is used as the drive source to move the load port door 8 forward / backward and up / down is advantageous in terms of reducing the number of parts.

[0039] The load port door 8 of this embodiment is equipped with a coupling switching mechanism 82 that releases the engagement (latched state) between the container door 33 and the container body 32 to place the container door 33 in an unlatched state, allowing it to be removed from the container body 32 (see FIG. 4 ). The load port 1 of this embodiment can also be equipped with a bottom purge unit that is attached to the mounting table 5 and that can inject an environmental gas (such as nitrogen gas, inert gas, or dry air) into the containment vessel 3 from the bottom side of the containment vessel 3 to replace the gaseous atmosphere inside the containment vessel 3 with the environmental gas. The bottom purge unit mainly comprises a plurality of nozzles (not shown) that are provided at predetermined locations on the mounting table 5. The plurality of nozzles function as bottom purge injection nozzles that inject the predetermined environmental gas and bottom purge discharge nozzles that discharge the gaseous atmosphere inside the containment vessel 3. These nozzles can be connected by fitting them into inlet and outlet ports (both not shown) provided at the bottom of the containment vessel 3. The purging process can be performed by supplying environmental gas from the bottom purge injection nozzle via the inlet into the internal space 3S of the containment vessel 3, and discharging the gas atmosphere of the internal space 3S of the containment vessel 3 from the bottom purge discharge nozzle via the outlet (this gas atmosphere is air or a low-purity environmental gas other than air for a predetermined time from the start of the purging process, and after the predetermined time has elapsed it is a high-purity environmental gas filled in the internal space 3S of the containment vessel 3).

[0040] As shown in Figure 3, the mapping mechanism M is equipped with three mapping sensors M1, M2, and M3 that can detect the presence or absence of transport objects W stored in multiple stages in the height direction H through each slot (multi-stage slot) 34 provided in the storage container 3, a mapping arm M4 that supports the three mapping sensors M1, M2, and M3 at the same height position, and a discrimination unit M5 that determines whether the storage condition of the transport objects W is good or bad based on the sensing information from the three mapping sensors M1, M2, and M3, and is capable of detecting the presence or absence of the transport objects W in the storage container 3 and their storage posture.

[0041] The mapping sensors M1, M2, and M3 function as end face detection units capable of detecting the end face Wa of the transport target W, and in this embodiment, photoelectric sensors are used as the mapping sensors M1, M2, and M3, which irradiate light such as visible light or infrared light from a light-projecting unit, and detect changes in the amount of light reflected or blocked by the transport target W, which is the detection object, with a light-receiving unit to acquire an output signal (sensing information). In particular, in this embodiment, a reflective photoelectric sensor (reflective sensor) is used, in which a transmitter (light-emitting sensor, light-emitting element) that emits a beam (ray light) and a receiver (light-receiving sensor, light-receiving element) that receives the beam emitted from the light-emitting element and reflected by the end face Wa of the transport target W are built into one sensor amplifier.

[0042] As shown in FIGS. 3 and 5(a), the three mapping sensors M1, M2, and M3 of the mapping mechanism M can be divided into a first mapping sensor M1 having a detection target area TA near one end 31a of the loading / unloading entrance 31 of the storage vessel 3, a second mapping sensor M2 having a detection target area TB near the other end 31b of the loading / unloading entrance 31, and a third mapping sensor M3 having a detection target area TC that is a predetermined area of ​​the loading / unloading entrance 31 between the detection target area TA by the first mapping sensor M1 and the detection target area TB by the second mapping sensor M2. As shown in FIG. 5(a), the detection target areas TA, TB, and TC of the mapping sensors M1, M2, and M3 are circular illumination areas illuminated by sensor light, and in particular, illumination areas with a diameter approximately equal to the thickness of one sheet of the transport object W to be detected. As can be seen from the figure, the three detection target areas TA, TB, and TC are at the same height. The detection target area of ​​the mapping sensor can be changed as appropriate depending on the thickness of the transport target object W. Also, the position of the mapping sensor (sensor position) can be configured to be adjustable in the left and right width directions.

[0043] 3, the detection target area TA of the first mapping sensor M1 is a portion near one end 31a of the loading / unloading entrance 31 of the storage container 3, specifically, an area that is closer to the center in the width direction of the loading / unloading entrance 31 by a predetermined distance than a slot 34a provided in one side wall of the container body 32 of the storage container 3. Furthermore, the detection target area TB of the second mapping sensor M2 is a portion near the other end 31b of the loading / unloading entrance 31 of the storage container 3, specifically, an area that is closer to the center in the width direction of the loading / unloading entrance 31 by a predetermined distance than a slot 34b provided in the other side wall of the container body 32 of the storage container 3. In other words, the detection target areas TA and TB of the first mapping sensor M1 and the second mapping sensor M2 are set so that the sensor light for detecting the presence or absence of the transport target object W does not irradiate the slot 34 (34a, 34b).

[0044] The detection target area TC of the third mapping sensor M3 is preferably located midway between the detection target area TA of the first mapping sensor M1 and the detection target area TB of the second mapping sensor M2 (the widthwise center of the loading / unloading entrance 31). However, in this embodiment, the detection target area TC is located a predetermined distance from the widthwise center of the loading / unloading entrance 31 toward the detection target area TA of the first mapping sensor M1. This is a measure to avoid interference between a protrusion sensor (not shown) and the third mapping sensor M3 in the load port 1 according to this embodiment. That is, if a transfer target W contained in the storage container 3 is located at a position protruding from the storage container 3 rather than its normal position during the mapping process, there is a risk that the mapping sensor M1 will collide with the transfer target W. To avoid this situation, if a protrusion sensor (for example, a protrusion sensor with the detection wave irradiation axis oriented in the height direction, not shown) that detects the protruding transfer target W is provided at the widthwise center of the loading / unloading entrance 31, it is necessary to avoid interference between the protrusion sensor and the third mapping sensor M3. In this embodiment, the detection target area TC of the third mapping sensor M3 is not the widthwise center of the loading / unloading entrance 31, but is an area included in the widthwise central portion of the loading / unloading entrance 31. Furthermore, by setting the detection target area TC of the third mapping sensor M3 to an area closer to the detection target area TA of the first mapping sensor M1 by a predetermined distance from the widthwise center of the loading / unloading entrance 31, it is possible to set the detection target area TC of the third mapping sensor M3 at a position that avoids the slots 34c that support the widthwise central portion of the object W. That is, similar to the detection target areas TA and TB of the first mapping sensor M1 and the second mapping sensor M2, the detection target area TC of the third mapping sensor M3 is also set so that the sensor light for detecting the presence or absence of the object W does not irradiate the slots 34c.

[0045] As shown in FIG. 3, the mapping arm M4 includes a long arm body M41 extending at least horizontally. The arm body M41 supports three mapping sensors M1, M2, and M3 fixed at predetermined positions spaced apart from each other in the horizontal direction. Each mapping sensor M1, M2, and M3 is supported with its tip pointing forward and protruding forward from the mapping arm M4. In this embodiment, as shown in FIG. 3, the direction in which the three mapping sensors M1, M2, and M3 are aligned (the mapping sensor parallel direction ML indicated by the two-dot chain line in the figure) is set parallel or approximately parallel to the extension direction of the end face Wa of the transport object W facing the loading / unloading entrance 31. The mounting and fixing positions of the mapping sensors M1, M2, and M3 relative to the mapping arm M4 are set so that a predetermined gap (e.g., 56 mm) is formed between the tip of each mapping sensor M1, M2, and M3 and the end face Wa of the transport object W. It may be acceptable to place the transport target W in a position within the storage vessel 3 that is offset (out of position) by a few millimeters from the normal position. In such cases, the mapping sensors M1, M2, and M3 may be configured to be adjustable to accommodate such offsets, thereby ensuring an appropriate separation distance between the tips of the mapping sensors M1, M2, and M3 and the end surface Wa of the transport target W. In the load port 1 of this embodiment, the mapping arm M4 is attached to a part that constitutes the door opening / closing mechanism 9 (see FIG. 1). Therefore, when the door opening / closing mechanism 9 raises or lowers the load port door 8, the mapping arm M4 also moves integrally. As a result, the entire mapping mechanism M moves up and down in the same direction as the load port door 8. Note that a configuration in which the mapping arm M4 is attached directly to the upper end of the load port door 8 or via another part may also be employed. Even in such a configuration, the entire mapping mechanism M moves up and down in the same direction as the load port door 8.

[0046] Note that the mapping mechanism M can be one that controls the elevation movement of the mapping arm M4 with a stepping motor (not shown) and can identify the height positions of the mapping sensors M1, M2, and M3 based on the number of pulses of the stepping motor. In this case, the mapping arm M4 moves up and down independently of the elevation movement of the load port door 8. In other words, it can be appropriately selected whether or not the mapping sensors M1, M2, and M3 of the mapping mechanism M share an elevation mechanism with the load port door 8.

[0047] The discrimination unit M5 discriminates whether the transport target W is accommodated properly based on sensing information from the three mapping sensors M1, M2, and M3. Each mapping sensor M1, M2, and M3 emits a beam (a line of light) as a signal and detects the presence or absence of the transport target W in the detection target areas TA, TB, and TC based on whether or not the signal is received. The trajectory of the beam (a line of light) can be regarded as a detection line. That is, the detection line during the mapping process consists of a straight line extending from the internal space 2S of the transport chamber 2 toward the end face Wa of the transport target W during signal transmission, and a straight line extending from the end face Wa of the transport target W toward the internal space 2S of the transport chamber 2 during signal reception, as shown by the straight arrows in FIG. 3. During mapping processing, when a signal (beam) is emitted forward from the transmitter of each mapping sensor M1, M2, M3, if the end face Wa of the transported object W is present in front of the transmitter, the signal reflected by the end face Wa of the transported object W reaches the receiver of each mapping sensor M1, M2, M3, whereas if the end face Wa of the transported object W is not present in front of the transmitter, the signal does not reach the receiver because it is not reflected by the end face Wa of the transported object W. Based on whether or not such a signal is received, it is possible to sequentially detect whether or not the end face Wa of the transported object W is present in the detection target areas TA, TB, TC of each mapping sensor M1, M2, M3.

[0048] Then, when all mapping sensors M1, M2, M3 receive signals simultaneously or approximately simultaneously (signal ON; when reflected light is received), that is, when the end surface Wa of the transporting object W is present in the detection areas TA, TB, TC of all mapping sensors M1, M2, M3 as shown in Figure 5(a), the discrimination unit M5 determines that the transporting object W is held in a normal posture (horizontal posture); when one of the three mapping sensors M1, M2, M3 receives a signal but all or one of the other mapping sensors do not receive a signal (signal OFF; when reflected light is not received), for example, when the end surface Wa of the transporting object W is not present in the detection area TB of the second mapping sensor M2 as shown in Figure 5(b), the discrimination unit M5 determines that the transporting object W is not held in a normal posture (abnormal cross mounting); and when all mapping sensors M1, M2, M3 do not receive a signal, the discrimination unit M5 determines that the transporting object W is not held. In this way, the discrimination unit M5 not only determines whether the object W is accommodated, but also determines whether the object W is accommodated in a horizontal position or whether the object W is abnormally placed crosswise (i.e., not placed horizontally) based on whether the three mapping sensors M1, M2, and M3 arranged horizontally simultaneously detect the object (signal ON). In particular, as shown in FIG. 5B, when a large object W is accommodated in a bent state due to its own weight or thinness, if the degree of bending is large, when one of the three mapping sensors M1, M2, and M3 receives a signal, all or one of the other mapping sensors will not receive a signal. Based on this detection information, the discrimination unit M5 determines that the object W is not accommodated in a normal position (i.e., a horizontal position). Bent placement can be considered one type of abnormal cross placement. In other words, if the object to be transported has a large (thick) thickness and is close to a rigid body, it will not bend, so if the discrimination unit M5 identifies such an object to be transported as being abnormally cross-mounted and not stored in a horizontal position, the object to be transported is stored in an overall tilted position (a position in which the overall linear shape in the width direction is maintained).On the other hand, as shown in Fig. 5(b), if the object W to be transported has a small (thin) thickness, and the discrimination unit M5 identifies this as an abnormal cross loading, this means that the object W to be transported is stored in a posture in which at least a portion of the object is bent. The abnormal cross loading shown in Fig. 5(b) is a state in which the area near the left end and the central portion in the width direction of the object W as viewed from the page are supported by slots 34a and 34c at the same height, while the object W is not supported by slots 34b at the same height as slots 34a and 34c, and the area near the right end as viewed from the page of the object W that is not supported by slot 34b is floating in the air. In addition, for example, a state in which the area of ​​the object W to be transported near the left end as viewed from the paper surface and the central portion in the width direction are supported by slots 34a and 34c at the same height position, while the area of ​​the object W to be transported near the right end as viewed from the paper surface is supported by slot 34b at a different height position from slots 34a and 34c (the area of ​​the object to be transported W near the right end as viewed from the paper surface is not floating in the air) is also one form of cross abnormal mounting. In this way, the mapping mechanism M of this embodiment determines whether the storage condition of the transport object W is good or bad by detecting the end face Wa of the transport object W using each mapping sensor M1, M2, M3, which has a predetermined detection area TA, TB, TC.

[0049] Furthermore, the mapping mechanism M of this embodiment also calculates the thickness of the transport object W based on the duration of signal reception (signal ON duration) by the mapping sensors M1, M2, and M3. When the mapping arm M4 is moved up and down using a stepping motor, the thickness of the transport object W is also calculated based on the number of pulses of the stepping motor from the duration of signal reception (signal ON duration) by the mapping sensors M1, M2, and M3. In this embodiment, to improve processing efficiency, only the signal ON duration of the third mapping sensor M3 is measured, and the signal ON durations of the other mapping sensors (first mapping sensor M1, second mapping sensor M2) are not measured. This is because whether multiple transport objects W are stored in a stacked state can be determined from the thickness of at least one location of the stored transport objects W.

[0050] The load port 1 according to this embodiment executes predetermined operations by issuing drive commands to each part and mechanism from the control unit 1C. The control unit 1C is configured with a storage unit, ROM, RAM, I / O ports, a CPU, an input / output interface (IF) for inputting and outputting data to and from an external display device, etc., and a bus interconnecting these to transmit information between each part.

[0051] The storage unit stores control procedures (operation sequences) according to the type of processing to be executed by the load port 1. In other words, the storage unit stores predetermined operation programs. In this embodiment, the programs are stored as executable programs on a non-transitory computer-readable recording medium (such as a hard disk).

[0052] ROM is a recording medium that consists of a hard disk, EEPROM, flash memory, etc., and stores the CPU's operating program, etc. RAM functions as the CPU's work area, etc. I / O ports, for example, output control signals from the CPU to each part and mechanism, and supply information from various sensors to the CPU.

[0053] The CPU constitutes the core of the control unit 1C and executes the operation program stored in the ROM, controlling the operation of the load port 1 in accordance with the program stored in the storage unit.

[0054] Next, the method of use (particularly the mapping processing method) and operation of the load port 1 according to this embodiment will be described with reference to FIG. 6 showing an operational flow.

[0055] First, an automatic storage vessel transfer device such as an OHT operates on a linear transfer line (traffic line) extending along the common wall surface 2F of the transfer chamber 2 on which the load port 1 is located. The storage vessel 3 is transferred to above the load port 1 and placed on the placement table 5. In the load port 1 according to this embodiment, the control unit 1C executes a seating retention process St1, which uses the seating retention mechanism 6 to retain the storage vessel 3 on the placement table 5 (see FIG. 6 ). Specifically, the seating retention process St1 in this embodiment involves locking the locking claws 61 on the placement table 5 by engaging with lockable portions (not shown) provided on the bottom surface of the storage vessel 3 or the frame cassette C, thereby locking the storage vessel 3 or the frame cassette C. This allows the storage vessel 3 or the frame cassette C to be placed and fixed at a predetermined position on the placement table 5. When the storage vessel 3 is placed on the placement table 5, the positioning protrusions 51 on the placement table 5 fit into the positioning recesses on the storage vessel 3.

[0056] In this embodiment, it is possible to place a storage container 3 on each of the loading tables 5 of the three load ports 1 arranged side by side in the width direction of the transfer chamber 2, and it is also possible to configure the system to detect whether the storage container 3 has been placed in a seating position on the loading table 5 using a seating sensor (not shown) that detects whether the storage container 3 is placed in a predetermined position on the loading table 5.

[0057] Following the seating and holding process St1, in the load port 1 of this embodiment, the control unit 1C causes the traction mechanism 7 to move the loading table 5 backward from the seating position toward the frame 4 to the transfer position for the transported object (rearward traction process St2). This rearward traction process St2 makes it possible to couple (dock) the container door 33 to the load port door 8, which has been placed on standby in the fully closed position, and to hold them in a tight contact state. In this embodiment, the container door 33 is coupled to the load port door 8 using the engagement portion 81 provided on the load port door 8, and is held in a tight contact state.

[0058] In the load port 1 of this embodiment, when the storage container 3 is placed at a seating position on the placement table 5, the control unit 1C detects that the bottom surface of the storage container 3 presses, for example, a pressure sensor provided on the placement table 5, and in response to this, the control unit 1C issues a drive command (signal) to advance the bottom purge injection nozzle and bottom purge discharge nozzle provided on the placement table 5 above the upper surface of the placement table 5. As a result, these nozzles (bottom purge injection nozzle, bottom purge discharge nozzle) are connected to the inlet and outlet of the storage container 3, respectively, and the system becomes ready to perform the purging process.

[0059] In the load port 1 of this embodiment, the control unit 1C issues a drive command to execute a purging process St3 on the internal space 3S of the containment vessel 3. This purging process St3 is a process in which a predetermined environmental gas is supplied from the bottom purge injection nozzle via the inlet into the internal space 3S of the containment vessel 3, and gas that has been retained in the internal space 3S of the containment vessel 3 until then is discharged from the bottom purge discharge nozzle via the discharge port. This purging process St3 fills the internal space 3S of the containment vessel 3 with the environmental gas, thereby reducing the moisture concentration and oxygen concentration inside the containment vessel 3 to below predetermined values ​​in a short period of time, and thereby making the environment around the transport target object W inside the containment vessel 3 a low-humidity environment and a low-oxygen environment.

[0060] It is possible to apply a storage vessel 3 that has been subjected to a purging process before being placed on the mounting table 5, and the purging process St3 may be performed on such a storage vessel 3, or it is also possible to choose not to perform the purging process St3.

[0061] Next, in the load port 1 of this embodiment, the control unit 1C performs a process (unlatch process St4) in which the connection switching mechanism 82 releases the engagement between the container door 33 and the container body 32, thereby placing the container door 33 in an unlatched state in which it can be removed from the container body 32.

[0062] Following the unlatching process St4, in the load port 1 of this embodiment, the control unit 1C executes a process (door opening process St5) in which the door opening / closing mechanism 9 moves the load port door 8 backward from the fully closed position to the door open position, thereby opening the opening 41 of the frame 4. Specifically, the control unit 1C causes the door opening / closing mechanism 9 to move the load port door 8 a predetermined distance along the horizontal path described above from the fully closed position to the door open position. At this time, the load port door 8 moves while holding the container door 33 integrally with it by the engaging portion 81. Therefore, by the door opening process St5, the loading / unloading entrance 31 of the storage container 3 is also opened, similar to the opening 41 of the frame 4.

[0063] Next, in the load port 1 of this embodiment, the control unit 1C performs a mapping process St6 using the mapping mechanism M. The mapping process St6 is a process in which the mapping sensors M1, M2, and M3 acquire information about the transport target object W in the storage vessel 3 for each slot 34 while the mapping arm M4 is moved at a constant speed in the height direction. In this embodiment, the height positions of the mapping sensors M1, M2, and M3 immediately after the door opening process St5 are set to a position slightly above the uppermost slot 34 in the storage vessel 3. This height position of the mapping sensors M1, M2, and M3 is set as the mapping start height position. With this load port 1 of this embodiment, it is possible to perform the mapping process St6 immediately after the door opening process St5. Note that, because the load port 1 of this embodiment has performed the door opening process St5 prior to performing the mapping process St6, the opening 41 of the frame 4 and the loading / unloading entrance 31 of the storage vessel 3 are in an open state.

[0064] In the load port 1 of this embodiment, when the door opening / closing mechanism 9 moves the load port door 8 downward from the door open position to the fully open position, the entire mapping mechanism M also moves downward. As a result, the three mapping sensors M1, M2, and M3 move from the mapping start height position to a position lower than the lowest slot 34 (mapping end height position) while maintaining appropriate positions where the mapping process St6 can be performed. The control unit 1C performs sensing processing to detect whether or not a signal is received from each of the mapping sensors M1, M2, and M3 through the above procedure. In this embodiment, sensing processing is performed by the remaining two mapping sensors (the first mapping sensor M1 and the second mapping sensor M2) at the same timing as sensing processing by a preset one of the three mapping sensors M1, M2, and M3 (the third mapping sensor M3 in this embodiment). In this way, in this embodiment, the third mapping sensor M3 functions as the main mapping sensor, and the first and second mapping sensors M1 and M2 function as sub-mapping sensors that operate in synchronization with the main mapping sensor. The control unit 1C executes a mapping process St6 in which the discrimination unit M5 determines whether the accommodation state, including the presence or absence of the transport object W, for each slot 34 is good or bad based on the detection signal resulting from the sensing process.

[0065] The specific discrimination method in the discriminator M5 is as described above, and the mapping process St6 can identify whether the accommodation state of the transport object W in the discriminated slot 34 is normal, abnormal cross-loading, or no object W is present (empty slot). In the load port 1 of this embodiment, the controller 1C calculates the thickness of the transport object W based on the duration (signal ON duration) of signal reception by the mapping sensor (the third mapping sensor M3, which is the main mapping sensor in this embodiment) in the mapping process St6 using the mapping mechanism M, and the discriminator M5 determines whether multiple transport objects W are accommodated in a stacked state based on the calculation result. In other words, if the duration of signal reception is equal to or longer than a predetermined time, the discriminator M5 determines that multiple transport objects W are accommodated in a stacked state (double abnormal loading).

[0066] In the load port 1 according to this embodiment, the control unit 1C executes a process in which the transport robot 21 transports the transport object W stored in a normal posture sequentially to a predetermined destination (processing chamber R (specifically, a load lock chamber), a buffer station, an aligner, etc.) based on the results of the mapping process St6.

[0067] On the other hand, if it is determined based on the detection result of the mapping process St6 that a transport object W that is not stored in a normal orientation is stored (if abnormal cross loading or abnormal double loading is determined), the storage container 3 on the placement table 5 is transferred from the placement table 5 to another space by the automatic storage container transfer device. This makes it possible to avoid a situation in which the transport object W that is in an abnormal cross loading state is damaged or broken when it is transferred by the transfer robot 21. When a new storage container 3 is placed on the placement table 5 by the automatic storage container transfer device, the above-mentioned operation sequence is performed.

[0068] According to the load port 1 of this embodiment described above, it is possible to execute the mapping process St6 using the mapping mechanism M that maps information regarding the state, including the presence or absence of the object W to be transported, in each slot 34 in the storage vessel 3. The mapping process St6 maps information regarding the storage state, including the presence or absence of the object W to be transported, in each slot 34 in the storage vessel 3, and it is possible to identify whether the object W to be transported is normally loaded, or whether there is a cross abnormal loading or a double abnormal loading, based on the detection results of the mapping process St6.

[0069] That is, according to the load port 1 of this embodiment, the three mapping sensors M1, M2, and M3 are arranged side by side on a common mapping arm M4 at a distance from each other in the horizontal direction, and the detection target areas TA, TB, and TC of the respective mapping sensors M1, M2, and M3 are set to three locations in total: the areas near both ends 31a and 31b of the loading / unloading entrance 31 of the storage container 3, and the central part in the width direction of the loading / unloading entrance 31. Therefore, when all three mapping sensors M1, M2, and M3 simultaneously detect the end face Wa of the transport target W, the discrimination unit M5 determines whether these three mapping sensors Based on the sensing information from M1, M2, and M3, it can be determined that the transport target W is accommodated in a horizontal position. If one mapping sensor detects the end face Wa of the transport target W but at least one of the other two mapping sensors does not detect the end face Wa of the transport target W, the discrimination unit M5 can determine, based on the sensing information from these three mapping sensors M1, M2, and M3, that the transport target W is not accommodated in a horizontal position but is accommodated in an oblique position (abnormal cross-mounting, including skewed mounting). Therefore, with the load port 1 according to this embodiment, it is possible to accurately and precisely detect the accommodation state of even a large, thin transport target W that has a rectangular planar shape within the storage vessel 3. Furthermore, with the load port 1 according to this embodiment, the mapping mechanism M can map information regarding the accommodation state, including the presence or absence of the transport target W in each slot 34 within the storage vessel 3, without photographing or image processing. This allows for faster detection of the transport target W and reduces system costs compared to image processing systems that use cameras or the like.

[0070] Additionally, with the load port 1 according to this embodiment, the mapping arm M4 moves up and down integrally with the load port door 8 when opening and closing the opening 41 of the frame 4. This eliminates the need for a mechanism for independently moving the mapping arm M4 up and down, and yet makes it possible to execute a mapping process St6 by the mapping mechanism M at the same time as the process of opening and closing the opening 41, thereby improving the operating rate in semiconductor manufacturing.

[0071] Furthermore, in the load port 1 according to this embodiment, sensing processing is performed by the sub-mapping sensors, which are the remaining two mapping sensors (the first mapping sensor M1 and the second mapping sensor M2), at the same time as sensing processing by one pre-set main mapping sensor (the third mapping sensor M3) among the three mapping sensors M1, M2, and M3, thereby shortening the processing time required for the discrimination unit M5 to determine whether the storage condition of the transport object W is good or bad based on the sensing information from the three mapping sensors M1, M2, and M3.

[0072] Furthermore, in the load port 1 according to this embodiment, the main mapping sensor (third mapping sensor M3) is configured to be able to detect the presence or absence of the end face Wa of the transport object W and the thickness of the end face Wa of the transport object W, and the sub-mapping sensors (first mapping sensor M1, second mapping sensor M2) are configured to be able to detect only the presence or absence of the end face Wa of the transport object W. Therefore, despite having the simplest configuration, in addition to detecting the presence or absence of the transport object W and detecting abnormal cross loading at the time of sensing processing by each mapping sensor M1, M2, M3, it is also possible to quickly and reliably determine whether or not the transport object W is stored in a state where multiple objects W are stacked on top of each other (abnormal double loading).

[0073] Furthermore, the mapping processing method for the load port 1 employed in this embodiment provides the same various effects as those provided by the load port described above, and can improve the operating rate in semiconductor manufacturing.

[0074] The present invention is not limited to the above-described embodiment. For example, the mapping mechanism may be equipped with three or more mapping sensors, and a mapping mechanism in which four or more mapping sensors are supported on a common mapping arm may be employed depending on the size of the transport object and the required detection accuracy.

[0075] Alternatively, either the first or second mapping sensor, which has a detection target area near the end of the loading / unloading entrance, may be set as the main mapping sensor, and the remaining two or more mapping sensors may be set as sub-mapping sensors that operate in synchronization with the main mapping sensor. In other words, which of the three or more mapping sensors is set as the main mapping sensor can be determined arbitrarily.

[0076] In the present invention, it is also possible to configure the mounting position of the mapping sensor relative to the mapping arm to be changeable and adjustable depending on the size of the transport object, etc.

[0077] The mapping sensor is not limited to a photoelectric sensor, but may also be a proximity sensor or a laser distance sensor.

[0078] Furthermore, in the present invention, the mapping mechanism may be configured such that the mapping sensor is supported by a mapping arm so as to be rotatable horizontally or approximately horizontally, and the mapping sensor can be switched between the mapping position and the non-mapping position by moving it around the rotation axis. Alternatively, a configuration may be adopted in which the entire mapping arm tilts to tilt the mapping sensor forward and position it at the mapping position, or a configuration in which the entire mapping arm slides toward the containment vessel to move the mapping sensor toward the containment vessel and position it at the mapping position.

[0079] Furthermore, the mapping process may be performed after the transport robot has placed the transport object in the storage container on the load port.

[0080] The load port according to the present invention can also be applied to transport devices other than EFEM.

[0081] Furthermore, for example, it is possible to arrange a plurality of load ports according to the present invention on the wall of a transfer chamber and use them as part of a sorter device that can exchange objects to be transferred between storage containers placed on the loading tables of each load port using a transfer robot located within the transfer chamber.

[0082] The number of load ports arranged on the wall surface of the transfer chamber may be one. In the above embodiment, the frame of the load port forms part of the outer wall of the transfer chamber, but the frame may be provided along the outer wall of the transfer chamber.

[0083] The glass substrates exemplified as the transport objects in the above-described embodiments bend differently depending not only on their thickness but also on their composition. Although such glass substrates, particularly thin glass substrates with a thickness of less than 0.4 mm, are prone to bending, the mapping mechanism of the load port according to the present invention can appropriately determine whether they are loaded in the correct orientation within the storage vessel. The transport object may also be a reticle, a liquid crystal transport object, a culture plate, an incubation vessel, a dish, a petri dish, or the like. In other words, the present invention can be applied to load ports that transfer transport objects housed in containers in various fields, such as semiconductors, liquid crystals, and cell culture.

[0084] The container for containing the transported object may be an appropriate container depending on the size of the object. An open-type container without a container door may also be used. The number of slots supporting one transported object, the position of the slots within the container, and the shape of the slots may also be selected and changed as appropriate. For example, slots may be provided only at positions that support both sides of the transported object, or at positions that overlap the detection area of ​​the mapping sensor in the height direction. Making the slots undetectable by the mapping sensor or, even if the mapping sensor detects the slots, providing a configuration that allows the detection information to be differentiated from the detection information when the edge of the transported object is detected is also an effective measure to avoid false detection.

[0085] In the above-described embodiment, the load port is equipped with a control unit, and the control unit controls the operation of each unit, such as the movement of the load port door, but it is also possible to configure the load port so that the operation of the load port is also controlled by a control unit (the control unit for the entire EFEM or the control unit for the processing chamber, which is a higher-level controller) that controls the operation of the higher-level device of the load port (the EFEM or the processing chamber in the above-described embodiment).

[0086] Furthermore, the above-mentioned control unit can be realized using a normal computer system, not a dedicated system. For example, a control unit that executes the above-mentioned processes can be configured by installing a program for executing the above-mentioned processes from a recording medium storing the program into a general-purpose computer. The means for providing these programs is arbitrary. As described above, the programs can be provided via a predetermined recording medium, or, for example, via a communication line, a communication network, a communication system, etc. In this case, for example, the program posted on a bulletin board (BBS) of a communication network can be provided by superimposing it on a carrier wave via network communication. The above-mentioned processes can be performed by launching the provided program and executing it under the control of the OS in the same way as other application programs.

[0087] Furthermore, the specific configuration of each part is not limited to the above embodiment, and various modifications are possible within the scope of the present invention. [Explanation of symbols]

[0088] 1. Loading port 3...Containment vessel 32...Container door 34...Slot 4...Frame 41...Opening 8...Load port door M...mapping mechanism M1: First mapping sensor (sub-mapping sensor) M2: Second mapping sensor (sub-mapping sensor) M3...Third mapping sensor (main mapping sensor) M4...mapping arm M5...discrimination part W: Object to be conveyed

Claims

1. a flat frame disposed in an upright position and having an opening through which the object to be conveyed can pass in a substantially horizontal position; a load port door that can be engaged with a container door that can open and close an entrance for the objects to be transported in a storage container having slots that can accommodate the plurality of objects to be transported in multiple stages, and that can open and close the opening of the frame; a mapping mechanism that maps information regarding a storage state including the presence or absence of the object to be transported in the slots of each stage in the storage vessel through the opening and the loading / unloading port that are in an open state, The slots of each stage include two slots that support both side portions of the object to be conveyed at the same height position, and a slot that supports a central portion of the object in the width direction at the same height position as the two slots, The mapping mechanism includes: a mapping arm that moves up and down integrally with or independently of the load port door when opening and closing the opening; three or more mapping sensors supported by the mapping arm and capable of detecting an end face of the object to be conveyed without photographing or image processing; a determination unit that determines whether the storage state of the object to be transported is good or bad based on sensing information from the three or more mapping sensors, a detection target area by a first mapping sensor among the three or more mapping sensors is set to a portion of the storage container near one end of the loading / unloading entrance, a detection target area by a second mapping sensor is set to a portion of the storage container near the other end of the loading / unloading entrance, and a detection target area by a third mapping sensor is set to a central portion of the loading / unloading entrance in the width direction, the detection target areas are set so that sensor light from the first mapping sensor and the second mapping sensor does not irradiate the two slots supporting both side portions of the transport object, and the detection target area is set so that sensor light from the third mapping sensor does not irradiate the slot supporting the central portion of the transport object in the width direction.

2. A load port as described in Claim 1, wherein the detection area is configured to be changeable depending on the thickness of the object to be transported.

3. 3. The load port according to claim 1, wherein each of the mapping sensors is set so as to irradiate the sensor light in a direction perpendicular to an end face of the object.

4. The mapping sensors are configured to be able to detect the presence or absence of an end surface and a thickness of the object to be conveyed based on the sensing information of a preset main mapping sensor among the three or more mapping sensors and the number of pulses of a stepping motor that moves the mapping arm up and down, and the mapping sensors are configured to be able to detect the presence or absence of an end surface of the object to be conveyed by a sub-mapping sensor that is a mapping sensor other than the main mapping sensor among the three or more mapping sensors; 4. The load port according to claim 1, wherein the sensing process by the sub-mapping sensor is performed at the same timing as the sensing process by the main mapping sensor.

5. the object to be conveyed is a rectangular substrate, each mapping sensor is set in a direction parallel or substantially parallel to an extension direction of the end surface of the transport object; 5. The load port according to claim 1, wherein the mapping mechanism determines whether the object is in a good or bad state by detecting an end face of the object using each mapping sensor having a predetermined detection target area.

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