Method for mapping object to be transported and efem

Abstract

To provide a load port and a mapping processing method capable of accurately and correctly detecting a storage state of a conveyance object in a storage container even when the conveyance object has a rectangular planar shape and is large, without increasing the size of the entire device.SOLUTION: The load port includes a frame having an opening through which an object to be transported can pass, a load port door capable of engaging with a container door 32 capable of opening and closing a loading / unloading port 31 of a storage container 3 having slots capable of accommodating the object to be transported in multiple stages and capable of opening and closing the opening of the frame, and a mapping mechanism M for mapping information on the object to be transported in each slot in the storage container. This carrying device has two mapping sensors M1 and M2 capable of detecting an end surface Wa of the carrying object by irradiating a detection wave, and a discriminating part MT for discriminating the quality of the storage state of the carrying object based on its sensing information.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, 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. [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 movable 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 can detect whether or not a transfer object is contained in each of the multi-stage slots (presence / absence detection). Furthermore, the mechanism simultaneously detects abnormal cross-loading (cross detection), where transfer objects are supported in slots at different heights, and double-loading (double detection), where two transfer objects are supported overlapping each other in the same slot. 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 its main object is to provide a load port that can accurately and precisely detect the storage state within a storage vessel, even if the transport target is large and has a rectangular planar shape, without increasing the size of the entire device. [Means for solving the problem]

[0014] That is, the load port of the present invention comprises a frame having an opening through which an object to be transported can pass in a substantially horizontal position; a load port door that is engageable with a container door that can open and close a loading / unloading entrance of a storage container having slots that can accommodate the object to be transported in multiple stages and that can open and close the opening of the frame; and a mapping mechanism that maps information related to the storage state including the presence or absence of the object to be transported in each of the slots in the storage container through the opening and the loading / unloading entrance, wherein the mapping mechanism is characterized by having two mapping sensors that move up and down integrally with or independently of the load port door that moves up and down when opening and closing the opening, and that are capable of detecting the end faces of the object to be transported by irradiating detection waves toward the inside of the storage container, and a discrimination unit that discriminates whether the storage state of the object to be transported is good or bad based on the sensing information from the two mapping sensors.

[0015] According to the load port of the present invention, it is possible to map information regarding the storage state, including the presence or absence of an object to be transferred, in each slot in the storage vessel using a mapping mechanism having two mapping sensors.

[0016] Therefore, with the load port of the present invention, even if the transported object is a large, thin object that has a rectangular planar shape and a straight end face that spans almost the entire opening width of the containment vessel's loading / unloading entrance, the two mapping sensors described above can accurately and precisely detect the storage state of the transported object within the containment vessel.

[0017] Furthermore, with the load port of the present invention, the mapping mechanism can map information regarding the storage status, including the presence or absence of an object to be transported, in each slot within the storage vessel without the need for photography or image processing. Compared to image processing systems that use cameras, etc., this speeds up the process of detecting the object to be transported and also makes it possible to keep the costs of the system low.

[0018] Here, in the present invention, a suitable example of a configuration in which information regarding the storage state, including the presence or absence of an object to be transported in each slot in the storage container, is "mapped without photographing or image processing" is a configuration in which each mapping sensor having the above-mentioned predetermined detection target area detects the end face of the object to be transported (determines whether the storage state of the object to be transported is good or bad)."

[0019] Furthermore, in the load port of the present invention, of the two mapping sensors arranged side by side in the horizontal direction, the detection target area by the first mapping sensor is set to a portion on one end side of the loading / unloading entrance, and the detection target area by the second mapping sensor is set to a portion on the other end side of the loading / unloading entrance.

[0020] According to the load port of the present invention, two mapping sensors are arranged side by side on a common mapping arm, spaced apart horizontally from each other, and each detects one end portion and the other end portion of the end face facing the loading / unloading entrance of the object to be transported.This makes it possible for the discrimination unit to reliably determine that the object to be transported is stored in a horizontal position based on the sensing information from the two mapping sensors, compared to when two detection target areas are set only on one end portion or only on the other end portion of the loading / unloading entrance of the storage vessel.

[0021] In addition, in the load port of the present invention, the discrimination unit detects the height position of the transported object based on sensing information from at least one of the two mapping sensors, and compares that height position with the normal height position of the transported object in each of the slots to determine whether the transported object is at a normal height position in each of the slots.

[0022] According to the load port of the present invention, the height position of the transported object can be detected based on sensing information from at least one of the two mapping sensors, making it possible to reliably detect whether the transported object in each slot in the storage container is in its normal position.

[0023] In addition, in the load port of the present invention, the mapping mechanism is characterized in that, before starting sensing to determine whether the storage condition of the transport object is good or bad using the two mapping sensors, it performs sensing using at least one of the two mapping sensors to detect whether the transport object stored in the storage container has protruded.

[0024] According to the load port of the present invention, at least one of the two mapping sensors is used to detect whether an object stored in a storage vessel has protruded, eliminating the need to install a separate sensor for detecting whether an object has protruded, thereby reducing manufacturing costs.

[0025] In the load port of the present invention, the beam emitted from at least one of the two mapping sensors has a strip shape extending along the edge of the transport object.

[0026] According to the load port of the present invention, the beam emitted from at least one of the two mapping sensors can stably detect the end face of the transported object and is less susceptible to the influence of external disturbances. [Effects of the Invention]

[0027] The present invention provides two mapping sensors spaced apart horizontally, and these two mapping sensors can accurately and precisely detect the storage status of the objects to be transported within the storage vessel without the need for photography or image processing. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 2 is a side view schematically showing the relative positional relationship between the EFEM equipped with the load port of the first embodiment of the present invention and its peripheral devices. [Figure 2] FIG. 2 is a plan view showing a simplified relative positional relationship of the load ports in FIG. [Figure 3] 2 is a diagram showing a schematic diagram of the relative positional relationship between the mapping mechanism and the transfer target accommodated in a slot in the storage vessel of the load port of FIG. 1. FIG. [Figure 4] FIG. 2 is a front view showing the load port of FIG. 1 with some parts omitted. [Figure 5] 2 is a diagram schematically showing a detection target area of ​​a mapping sensor on the load port of FIG. 1. FIG. [Figure 6] 2 is a flowchart showing the operation procedure of the load port of FIG. 1. [Figure 7] 10 is a diagram showing a schematic diagram of the relative positional relationship between a transfer target accommodated in a slot in a storage vessel and a mapping mechanism in a load port according to a second embodiment of the present invention. FIG. [Figure 8] 8 is a diagram schematically showing a detection target area of ​​a mapping sensor on the load port of FIG. 7. FIG. [Figure 9] FIG. 8 is a diagram showing a control block of the load port of FIG. 7. [Figure 10] 8 is a diagram showing the lifting range of a mapping sensor on the load port of FIG. 7. FIG. [Figure 11] 8A to 8C are diagrams illustrating a method for detecting the height position of a mapping sensor in the load port of FIG. 7. [Figure 12] 8A and 8B are diagrams illustrating normal height positions of objects to be transferred placed on each slot in the load port of FIG. 7. [Figure 13] 10A and 10B are diagrams illustrating a method for moving a mapping sensor in a load port according to a third embodiment of the present invention. [Figure 14] 14A to 14C are diagrams illustrating a method of moving a mapping sensor on the load port of FIG. 13. [Figure 15] 10A and 10B are diagrams illustrating a modified example of a method for determining whether an object to be conveyed is accommodated in a normal posture. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0030] (First embodiment) The load port 1 of 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 can 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 to be transferred 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).

[0031] 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).

[0032] 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 stationary robot may also be used as the transfer robot.

[0033] 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.

[0034] 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.

[0035] 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 slot 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 ).

[0036] 1 and the like, the load port 1 of 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 of the slots 34 (34a, 34b, 34c) in the storage container 3 that is at the transfer object delivery position.

[0037] 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.

[0038] 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.

[0039] The seating holding mechanism 6 holds the storage container 3 on the loading table 5 by hooking a locking claw (not shown) 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 with respect to the locked portion.

[0040] 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.

[0041] 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.

[0042] In this embodiment, in the front-rear direction D (see FIG. 1 etc.) in which the storage vessel 3 placed on the mounting table 5 and the frame 4 are aligned, the storage vessel 3 side is defined as the front, and the frame 4 side is defined as the rear.

[0043] The load port door 8 is movable between a fully closed position in which it seals the opening 41 of the frame 4, a door open position in which it is retreated toward the transfer chamber 2 from the fully closed position, and a fully open position in which it 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 show the appearance of the load port door 8 and the mapping mechanism M (described below), but in actual operation, the load port door 8 is positioned in the door open position when the containment vessel 3 has been moved to the transfer object delivery position (a position in which the vessel body 32 is in close contact with the load port door 8) and the vessel door 33 is engaged and held. In other words, it is essential that the interior of the EFEM and the transfer chamber 2 is not opened to the outside space.

[0044] The load port door 8 has an engaging portion 81 that can attract and hold the container door 33 of the storage container 3 (see FIG. 4 ). The load port door 8 is configured to be movable integrally with the container door 33 between a fully closed position, a door open position, and a fully open position while maintaining an engaged state with the container door 33. The movement paths of the load port door 8 between the fully closed position and the fully open position consist of a horizontal path (where 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) and a vertical path (where 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 behind the frame 4 (where it is completely separated from the container body 32 and located in the internal space 2S of the transfer chamber 2).

[0045] 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.

[0046] 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 (also referred to as purge gas; in this embodiment, nitrogen gas or dry air is mainly used). 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.

[0047] These multiple nozzles can be connected in a fitted state to an inlet and an outlet (both not shown) provided at the bottom of the containment vessel 3. Purge treatment can be performed by supplying environmental gas from the bottom purge injection nozzle via the inlet to the internal space 3S of the containment vessel 3, and discharging the gas atmosphere in 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 purge treatment, 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).

[0048] As shown in Figure 3, the mapping mechanism M comprises two mapping sensors M1 and M2 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 Mt that supports the two mapping sensors M1 and M2 at the same height position, and a discrimination unit MT that determines whether the storage condition of the transport objects W is good or bad based on the sensing information from the two mapping sensors M1 and M2, and is capable of detecting the presence or absence of the transport objects W in the storage container 3 and their storage posture.

[0049] The mapping sensors M1 and M2 function as end face detection units capable of detecting the end face Wa of the transport target W. In this embodiment, photoelectric sensors are used as the mapping sensors M1 and M2, which emit 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, this embodiment uses a reflective photoelectric sensor (reflective sensor) 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.

[0050] As shown in FIGS. 3 and 5(a), the two mapping sensors M1 and M2 of the mapping mechanism M can be divided into a first mapping sensor M1 having a detection target area TA on one end 31a of the loading / unloading entrance 31 of the storage vessel 3, and a second mapping sensor M2 having a detection target area TB on the other end 31b of the loading / unloading entrance 31. The detection target areas TA and TB of the mapping sensors M1 and M2 are circular illumination areas of sensor light, as shown in FIG. 5(a), and are illumination areas with a diameter approximately equal to the thickness of one transport object W to be detected. As can be seen from the figure, the two detection target areas TA and TB are at the same height. The detection target areas of the mapping sensors can be appropriately changed depending on the thickness of the transport object W. The position of the mapping sensor (sensor position) can also be configured to be adjustable in the left-right and width directions.

[0051] 3, the detection target area TA of the first mapping sensor M1 is a portion on one end 31a side of the loading / unloading entrance 31 of the storage container 3, specifically, a region at a midpoint between a slot 34a provided in one sidewall of the container body 32 of the storage container 3 and a slot 34c provided in the widthwise center of the container body 32 (the widthwise center of the loading / unloading entrance 31). The detection target area TB of the second mapping sensor M2 is a portion on the other end 31b side of the loading / unloading entrance 31 of the storage container 3, specifically, a region at a midpoint between a slot 34b provided in the other sidewall of the container body 32 of the storage container 3 and a slot 34c provided in the widthwise center of the container body 32 (the widthwise center of the loading / unloading entrance 31). 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, 34c).

[0052] In the load port 1 of this embodiment, if the transport object W contained in the storage container 3 during the mapping process is located at a position that protrudes from the storage container 3 more than its normal position, there is a risk that the mapping sensors M1 and M2 will collide with the transport object W. To avoid this situation, 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 transport object W is provided in the center of the width of the loading / unloading entrance 31.

[0053] As shown in FIG. 3, the mapping arm Mt is a long arm extending horizontally and supports two mapping sensors M1 and M2 in a fixed state at predetermined positions spaced apart from each other in the horizontal direction. Each mapping sensor M1 and M2 is supported with its tip facing forward and protruding forward from the mapping arm Mt. In this embodiment, as shown in FIG. 3, the direction in which the two mapping sensors M1 and M2 are aligned (the mapping sensor parallel direction ML indicated by the two-dot chain line in the figure) is set to be parallel or approximately parallel to the extension direction of the end face Wa of the transport object W facing the loading / unloading entrance 31. In addition, the mounting and fixing positions of the mapping sensors M1 and M2 with respect to the mapping arm Mt are set so that a predetermined gap (e.g., 56 mm) is formed between each tip of the mapping sensors M1 and M2 and the end face Wa of the transport object W.

[0054] It is sometimes 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 its normal position. In such cases, the mapping sensors M1, M2 can be configured to be adjustable to accommodate this offset, thereby ensuring an appropriate distance between the tips of the mapping sensors M1, M2 and the end face Wa of the transport target W. In the load port 1 of this embodiment, the mapping arm Mt 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 Mt 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. It is also possible to attach the mapping arm Mt directly to the upper end of the load port door 8 via another part, or to attach the mapping sensors M1, M2 directly to the load port door 8 without using the mapping arm Mt. Even in this configuration, the entire mapping mechanism M moves up and down in the same direction as the load port door 8.

[0055] The mapping mechanism M can be one that controls the vertical movement of the mapping arm Mt with a stepping motor (not shown) and can identify the height positions of the mapping sensors M1, M2 based on the number of pulses of the stepping motor. In this case, the mapping arm Mt moves vertically independently of the vertical movement of the load port door 8. In other words, it can be appropriately selected whether or not the mapping sensors M1, M2 of the mapping mechanism M share a lifting mechanism with the load port door 8.

[0056] The discrimination unit MT determines whether the transport target W is accommodated properly based on sensing information from the two mapping sensors M1 and M2. Here, each mapping sensor M1 and M2 emits a beam (ray of light) as a signal and detects the presence or absence of the transport target W in the detection target areas TA and TB based on whether or not the signal is received, and the trajectory of the beam (ray of light) can be considered as the detection line. That is, the detection line during the mapping process consists of a straight line extending from the internal space 2S side 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 side of the transport chamber 2 during signal reception, as shown by the straight arrows in FIG. During mapping processing, when a signal (beam) is emitted forward from the transmitter of each mapping sensor M1, M2, if the end face Wa of the transport object W is present in front of the transmitter, the signal reflected by the end face Wa of the transport object W reaches the receiver of each mapping sensor M1, M2, whereas if the end face Wa of the transport 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 transport 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 transport object W is present in the detection target areas TA, TB of each mapping sensor M1, M2. Note that the discrimination unit MT is formed, for example, inside the control unit 1C.

[0057] When the two mapping sensors M1 and M2 receive signals simultaneously or approximately simultaneously (signal ON; when reflected light is received), that is, when the end surface Wa of the transport object W is present in the detection areas TA and TB of the two mapping sensors M1 and M2 as shown in Figure 5(a), the discrimination unit MT determines that the transport object W is held in a normal position (horizontal position); when one of the two mapping sensors M1 and M2 receives a signal but the other does not receive a signal (signal OFF; when reflected light is not received), for example, when the end surface Wa of the transport 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 MT determines that the transport object W is not held in a normal position (cross abnormal mounting); and when no signals are received from both mapping sensors M1 and M2, the discrimination unit MT determines that the transport object W is not held. In this way, the discrimination unit MT not only determines whether the transport object W is contained or not, but also determines whether the transport object W is contained in a horizontal position or whether the transport object W is not contained in a horizontal position and is abnormally cross-mounted, based on whether the two mapping sensors M1, M2 arranged side by side in the horizontal direction detect the object simultaneously or approximately simultaneously (signal ON).

[0058] In particular, as shown in FIG. 5(b), when a large object W to be transported is stored in a bent state due to its own weight, thinness, or the like, if the degree of bending is large, one of the two mapping sensors M1, M2 receives a signal at the same time as the other mapping sensor does not receive a signal. Based on this detection information, the discrimination unit MT determines that the object W is not stored in a normal (horizontal) position. A bent position can be considered as a type of abnormal cross-mounting. In other words, an object that is large (thick) and nearly rigid will not bend. Therefore, when the discrimination unit MT determines that such an object is not stored in a horizontal position, it means that the object is stored in an abnormal cross-mounting position (where the object is generally kept linear in the width direction).

[0059] 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 MT identifies the object W as having an abnormal cross loading, this means that the object W 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 portion of the object W to be transported from the region near the left end as viewed in the plane of the paper to the center in the width direction is supported by slots 34a and 34c at the same height position, while the object W is not supported by slots 34b at the same height position as slots 34a and 34c, and the portion of the object W to be transported that is not supported by slot 34b and is near the right end as viewed in the plane of the paper 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.

[0060] 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 each mapping sensor M1, M2 having a predetermined detection target area TA, TB detecting the end face Wa of the transport object W.

[0061] Furthermore, the mapping mechanism M of this embodiment also calculates the thickness of the transport object W based on the duration of signal reception by the mapping sensors M1 and M2 (signal ON duration). When the mapping arm Mt is moved up and down by 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 by the mapping sensors M1 and M2 (signal ON duration). In this embodiment, to improve processing efficiency, only the signal ON duration of the first mapping sensor M1 is measured, and the signal ON duration of the second mapping sensor M2 is not measured. This is because it is possible to determine whether multiple transport objects W are stored in a stacked state from the thickness of at least one location of the stored transport objects W.

[0062] The load port 1 of 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.

[0063] 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).

[0064] 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.

[0065] 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.

[0066] Next, the method of use (particularly the mapping processing method) and operation of the load port 1 of this embodiment will be described with reference to FIG. 6 showing an operational flow.

[0067] First, the storage vessel 3 is transported above the load port 1 by an automatic storage vessel transport device such as an OHT, which operates on a linear transport line (traffic line) extending along the common wall surface 2F of the transport chamber 2 on which the load port 1 is located, and placed on the placement table 5. In the load port 1 of this embodiment, the control unit 1C executes a seating retention process S1 in which the seating retention mechanism 6 holds the storage vessel 3 on the placement table 5 (see FIG. 6 ). Specifically, the seating retention process S1 in this embodiment involves hooking a locking claw on the placement table 5 onto a lockable portion (not shown) provided on the bottom surface of the storage vessel 3 or the frame cassette C to lock 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 protrusion 51 provided on the placement table 5 fits into the positioning recess of the storage vessel 3.

[0068] 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.

[0069] Following the seating and holding process S1, 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 S2). This rearward traction process S2 makes it possible to connect (dock) the container door 33 to the load port door 8, which has been placed on standby in the fully closed position, and hold them in a tight contact state. In this embodiment, the container door 33 is connected 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.

[0070] 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.

[0071] In the load port 1 of this embodiment, the control unit 1C issues a drive command to execute a purging process S3 on the internal space 3S of the containment vessel 3. This purging process S3 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 outlet. This purging process S3 fills the internal space 3S of the containment vessel 3 with the environmental gas, and reduces the moisture concentration and oxygen concentration inside the containment vessel 3 to below predetermined values ​​in a short period of time, thereby making the environment around the transport target object W inside the containment vessel 3 a low-humidity environment and a low-oxygen environment.

[0072] 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 S3 may be performed on such a storage vessel 3, or it is also possible to choose not to perform the purging process S3.

[0073] Next, in the load port 1 of this embodiment, the control unit 1C performs a process (unlatch process S4) 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.

[0074] Following the unlatch process S4, in the load port 1 of this embodiment, the control unit 1C executes a process (door opening process S5) 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 engagement portion 81. Therefore, by the door opening process S5, the loading / unloading entrance 31 of the storage container 3 is also opened, similar to the opening 41 of the frame 4.

[0075] Next, in the load port 1 of this embodiment, the control unit 1C performs a mapping process S6 using the mapping mechanism M. The mapping process S6 is a process in which the mapping sensors M1 and M2 acquire information about the transport target object W in the storage vessel 3 for each slot 34 while the mapping arm Mt is moved at a constant speed in the height direction. In this embodiment, the height positions of the mapping sensors M1 and M2 immediately after the door opening process S5 are set to a position slightly above the uppermost slot 34 in the storage vessel 3. This height position of the mapping sensors M1 and M2 is set as the mapping start height position. With this load port 1 of this embodiment, it is possible to perform the mapping process S6 immediately after the door opening process S5. Note that, because the load port 1 of this embodiment has performed the door opening process S5 prior to performing the mapping process S6, the opening 41 of the frame 4 and the loading / unloading entrance 31 of the storage vessel 3 are in an open state.

[0076] In the load port 1 of this embodiment, when the load port door 8 is moved downward from the door open position to the fully open position by the door opening / closing mechanism 9, the entire mapping mechanism M also moves downward. As a result, the two mapping sensors M1, M2 move from the mapping start height position to a position lower than the lowest slot 34 (mapping end height position) while being maintained at an appropriate position where the mapping process S6 can be executed. Through the above procedure, the control unit 1C performs sensing processing to detect whether or not a signal has been received from each of the mapping sensors M1, M2.

[0077] In this embodiment, sensing processing by one of the two mapping sensors M1, M2 (the first mapping sensor M1 in this embodiment) that has been preset is performed at the same time as sensing processing by the remaining mapping sensor (the second mapping sensor M2). In this way, in this embodiment, the first mapping sensor M1 functions as a main mapping sensor, and the second mapping sensor M2 functions as a sub-mapping sensor that operates in synchronization with the main mapping sensor. The control unit 1C executes a mapping processing S6 in which the discrimination unit M5 determines the quality of the storage condition, including the presence or absence of the transport object W, for each slot 34 based on the detection signal accompanying the sensing processing.

[0078] The specific discrimination method in the discriminator MT is as described above, and the mapping process S6 can identify whether the accommodation state of the transport object W in the slot 34 being discriminated is normal, abnormal cross-loading, or no object is loaded (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 (in this embodiment, the first mapping sensor M1, which is the main mapping sensor) in the mapping process S6 using the mapping mechanism M, and determines whether multiple transport objects W are accommodated in a stacked state using the calculation result. In other words, if the duration of signal reception is equal to or longer than a predetermined time, the discriminator MT determines that multiple transport objects W are accommodated in a stacked state (double abnormal loading).

[0079] In the load port 1 of this embodiment, the control unit 1C executes a process in which the transport object W stored in a normal posture is transported sequentially by the transport robot 21 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 S6.

[0080] On the other hand, if it is determined based on the detection results of the mapping process S6 that an object W to be transported is not stored in a normal orientation (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 object W to be transported is damaged or broken when the transfer robot 21 transports an object W in an abnormal cross loading state. 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.

[0081] According to the load port 1 of the present embodiment described above, the mapping process S6 can be executed 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 S6 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 based on the detection results of the mapping process S6, it is possible to identify whether the object W to be transported is being loaded normally, or whether there is an abnormal cross loading or an abnormal double loading.

[0082] As described above, the load port 1 of this embodiment comprises a frame 4 having an opening 41 through which the objects to be transported W can pass in a substantially horizontal position; a load port door 8 that is engageable with a container door 33 that can open and close the loading / unloading entrance 31 of a storage container 3 having slots 34 that can accommodate the objects to be transported W in multiple stages and that can open and close the opening 41 of the frame 4; and a mapping mechanism M that maps information related to the storage state, including the presence or absence of the objects to be transported W in each slot 34 within the storage container 3, through the opening 41 and the loading / unloading entrance 31. The mapping mechanism M moves up and down integrally with or independently of the lifting and lowering movement of the load port door 8 when opening and closing the opening 41, and has two mapping sensors M1, M2 that can detect the end face Wa of the objects to be transported W by irradiating a detection wave toward the inside of the storage container 3, and a discrimination unit MT that discriminates whether the storage state of the objects to be transported W is good or bad based on the sensing information from the two mapping sensors M1, M2.

[0083] According to the load port 1 of this embodiment, it is possible to map information relating to the storage state, including the presence or absence of the transport object W in each slot 34 in the storage vessel 3, using a mapping mechanism M having two mapping sensors M1 and M2.

[0084] Therefore, with the load port 1 of this embodiment, even if the transport object W is a large, thin object having a rectangular planar shape and a linear end face that spans almost the entire opening width of the loading / unloading entrance 31 of the storage vessel 3, the above-mentioned two mapping sensors M1, M2 can accurately and precisely detect the storage state of the object W within the storage vessel 3.

[0085] Furthermore, with the load port 1 of this embodiment, the mapping mechanism M can map information regarding the storage status, including the presence or absence of the object W to be transported, in each slot 34 in the storage vessel 3 without taking photographs or processing the images. Compared to image processing systems that use cameras or the like, this can speed up the process of detecting the object W to be transported and also makes it possible to keep the costs of the system low.

[0086] In addition, in the load port 1 of this embodiment, of the two mapping sensors M1, M2 arranged side by side horizontally, the detection target area TA by the first mapping sensor M1 is set to a portion on one end side of the loading / unloading entrance 31, and the detection target area TB by the second mapping sensor M2 is set to a portion on the other end side of the loading / unloading entrance 31.

[0087] According to the load port 1 of this embodiment, two mapping sensors M1, M2 are arranged side by side on a common mapping arm Mt, spaced apart horizontally from each other, and each detects one end portion and the other end portion of the end face of the transport object W facing the loading / unloading entrance 31. Compared to a case in which two detection target areas are set only at one end portion or only at the other end portion of the loading / unloading entrance 31 of the storage vessel 3, the discrimination unit MT can reliably determine that the transport object W is stored in a horizontal position based on the sensing information from the two mapping sensors M1, M2.

[0088] (Second embodiment) The load port 101 of this embodiment differs from the load port 1 of the first embodiment in that the beam shape of the mapping sensors M1 and M2 of the first embodiment is circular, whereas the beam shape of the mapping sensors M101 and M102 of this embodiment is strip-shaped, and in the method for determining whether the storage condition of the transport target object W is good or bad. Note that detailed description of the configuration of the load port 101 of this embodiment that is the same as that of the load port 1 of the first embodiment will be omitted.

[0089] In the load port 101 of this embodiment, as shown in FIG. 7, the mapping mechanism M includes two mapping sensors M101, M102 that can detect the presence or absence of transport objects W stored in multiple stages in the height direction H in each slot (multi-stage slot) 34 provided in the storage container 3, a mapping arm Mt that supports the two mapping sensors M101, M102 at the same height position, and a discrimination unit MT that discriminates whether the storage condition of the transport objects W is good or bad based on sensing information from the two mapping sensors M101, M102, and is capable of detecting the presence or absence of the transport objects W in the storage container 3 and their storage posture.

[0090] The mapping sensors M101, M102 function as end face detection units capable of detecting the end face Wa of the transport object W, and in this embodiment, photoelectric sensors are used as the mapping sensors M101, M102, 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 object W, which is the detection object, with a light-receiving unit to acquire an output signal (sensing information). In particular, this embodiment uses a reflective photoelectric sensor (reflective sensor) in which a transmitter (light-emitting sensor, light-emitting element) that emits a strip-shaped beam (linear light) extending along the end face Wa of the transport object W, 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 object W are built into one sensor amplifier.

[0091] As shown in FIG. 8(a), the detection target areas TA1 and TB1 of the mapping sensors M101 and M102 are rectangular areas illuminated by sensor light, and have a height (vertical length) approximately equal to the thickness of one transport object W to be detected, and a width (horizontal length) along the end face Wa of the transport object W. The detection target areas TA1 and TB1 are oblong in shape, with the width along the end face Wa of the transport object W being longer than the height. When detecting the end face Wa of a transport object W having a thickness of, for example, 0.4 to 3 mm, the height of the illumination area is, for example, 0.2 mm, and the width along the end face Wa of the transport object W is, for example, 1.5 mm. It is particularly preferable to set the height of the illumination area within the range of 0.05 to 0.2 mm and the width within the range of 1 to 1.5 mm.

[0092] The mapping mechanism M controls the vertical movement of the mapping arm Mt by a stepping motor 110. Therefore, the mapping arm Mt moves vertically independently of the vertical movement of the load port door 8. In other words, it is possible to appropriately select whether or not the mapping sensors M101, M102 of the mapping mechanism M share a vertical movement mechanism with the load port door 8.

[0093] 9, the discrimination unit MT has a motor control unit 111, a height position detection unit 112, a normal position storage unit 113, and a good / bad discrimination unit 114. The discrimination unit MT is connected to a stepping motor 110 and mapping sensors M101 and M102. The discrimination unit MT is formed, for example, inside the control unit 1C.

[0094] When performing the mapping process, the motor control unit 111 controls the stepping motor 110 to lower the mapping arm Mt from the mapping start height position, as shown in Fig. 10. The amount of downward movement of the mapping arm Mt is determined according to the number of pulses input to the stepping motor 110 by the motor control unit 111.

[0095] The height position detection unit 112 detects the descending distance of the mapping sensor M101 from the mapping start height position based on the number of pulses input to the stepping motor 110 by the motor control unit 111 when the mapping arm Mt is at the mapping start height position. That is, the height position detection unit 112 detects the height position of the mapping sensor M101. Note that the height position detection unit 112 in this embodiment detects the height position of the transport target object W (the height position of the detection target area TA by the mapping sensor M101) based on the sensing information of the mapping sensor M101.

[0096] For example, consider a case where, in a state where the mapping arm Mt is at the mapping start height position as shown in Fig. 11(a), when the motor control unit 111 inputs a pulse number a1 to the stepping motor 110, the end surface Wa of the object W to be transferred on the uppermost slot 34 in the storage vessel 3 is detected as shown in Fig. 11(b). At this time, based on the pulse number a1 input to the stepping motor 110, the height position detection unit 112 detects that the mapping sensors M101, M102 are at positions that have descended a distance d1 corresponding to the pulse number a1 from the mapping start height position until the end surface Wa of the object W to be transferred is detected by the mapping sensors M101, M102.

[0097] Similarly, when the motor control unit 111 inputs pulse number a2 to the stepping motor 110, if the end surface Wa of the object W to be transported on the second-highest slot 34 in the storage container 3 is detected as shown in Figure 11 (c), the height position detection unit 112 detects that the mapping sensors M101, M102 are at a position that has descended downward from the mapping start height position by a distance d2 corresponding to the pulse number a2 based on the pulse number a2 input to the stepping motor 110 until the end surface Wa of the object W to be transported is detected by the mapping sensors M101, M102.

[0098] The normal position memory unit 113 stores the normal height position of the transport object W when the transport object W is placed in a normal storage posture on each slot 34 in the storage container 3. In this embodiment, the normal position memory unit 113 stores the downward distance from the mapping start height position of the mapping arm Mt as the normal height position of the transport object W.

[0099] For example, the normal height position of the transport target W placed in the normal storage position in the uppermost slot 34 in the storage vessel 3 is a height position that is a distance D1 downward from the mapping start height position of the mapping arm Mt, as shown in Fig. 12. Similarly, the normal height positions of the transport target W placed in the second slot 34 from the top and the third slot 34 from the top in the normal storage position are height positions that are distances D2 and D3 downward from the mapping start height position of the mapping arm Mt, respectively. The same is true for the normal height positions of the transport target W placed in the normal storage position in the slots 34 below the fourth slot from the top.

[0100] The quality determining unit 114 determines whether the state of the objects W to be conveyed is good or bad based on the sensing information from the two mapping sensors M101 and M102.

[0101] First, when the end face Wa of the transport object W located on the slot 34 is detected in the detection target area TA by the mapping sensor M101, the pass / fail judgment unit 114 compares the height position of the mapping sensor M101 detected by the height position detection unit 112 at that time with the normal height position of the transport object W on each slot 34, thereby determining whether the portion of the end face Wa of the transport object W located in the detection target area TA is at the normal height position.

[0102] That is, the quality determination unit 114 determines that the portion of the end surface Wa of the transport object W that is in the detection target area TA is at a normal height when the height position of the mapping sensor M101 detected by the height position detection unit 112 matches the normal height position stored in the normal position memory unit 113 for each slot 34. On the other hand, when the height position of the mapping sensor M101 detected by the height position detection unit 112 does not match the normal height position stored in the normal position memory unit 113 for that slot 34, it determines that the portion of the end surface Wa of the transport object W that is in the detection target area TA is not at a normal height.

[0103] Thereafter, when the quality discriminator 114 determines that the portion of the end face Wa of the transport object W that is in the detection target area TA is at a normal height, it determines whether or not the end face Wa of the transport object W is detected by the mapping sensor M102 when the end face Wa of the transport object W is detected by the mapping sensor M101. In other words, when the end face Wa of the transport object W is present in the detection target area TA of the mapping sensor M101, the quality discriminator 114 determines whether or not the end face Wa of the transport object W is present in the detection target area TB of the mapping sensor M102.

[0104] In this way, the discrimination unit MT (good / bad discrimination unit 114) determines that the transported object W is stored in a normal posture (horizontal posture) when the portion of the end face Wa of the transported object W that is in the detection target area TA is at a normal height and the end face Wa of the transported object W is present in the detection target area TA of the mapping sensor M101, and the end face Wa of the transported object W is present in the detection target area TB of the mapping sensor M102.

[0105] In addition, if the end face Wa of the transport object W is detected by the mapping sensor M101 but the portion of the end face Wa of the transport object W that is in the detection target area TA is not at a normal height, the discrimination unit MT (good / bad discrimination unit 114) determines that the transport object W is not stored in a normal posture (horizontal posture).

[0106] Furthermore, when the mapping sensor M101 does not detect the end face Wa of the transport object W, the determination unit MT (good / bad determination unit 114) determines that the transport object W is not accommodated.

[0107] As described above, according to the load port 101 of this embodiment, it is possible to map information regarding the storage state, including the presence or absence of the transport object W in each slot 34 in the storage vessel 3, using the mapping mechanism M having two mapping sensors M101, M102.

[0108] In addition, in the load port 101 of this embodiment, the discrimination unit MT detects the height position of the transported object W based on the sensing information of the mapping sensor M101, and determines whether the transported object W is at a normal height position above each slot 34 by comparing that height position with the normal height position of the transported object W above each slot 34.

[0109] According to the load port 101 of this embodiment, the height position of the transport object W can be detected based on the sensing information of the mapping sensor M101, so it is possible to reliably detect whether the transport object W in each slot 34 in the storage container 3 is in the normal position.

[0110] In the load port 101 of this embodiment, the beams emitted from the two mapping sensors M101 and M102 have a strip shape extending along the end face Wa of the object W to be transferred.

[0111] According to the load port 101 of this embodiment, the beams emitted from the two mapping sensors M101 and M102 can stably detect the end face Wa of the transport target W and are less susceptible to disturbances.

[0112] (Third embodiment) The load port 201 of this embodiment differs from the load port 1 of the first embodiment in that the mapping sensor M102 is used as a protrusion sensor and in the method of determining whether the storage state of the transport object W is good or bad. Note that detailed description of the configuration of the load port 201 of this embodiment that is the same as that of the load port 1 of the first embodiment will be omitted.

[0113] In the load port 201 of this embodiment, as in the second embodiment, the mapping mechanism M includes two mapping sensors M101, M102 that can detect the presence or absence of transport objects W stored in multiple stages in the height direction H by each slot (multi-stage slot) 34 provided in the storage container 3, a mapping arm Mt that supports the two mapping sensors M101, M102 at the same height position, and a discrimination unit MT that determines whether the storage condition of the transport objects W is good or bad based on sensing information from the two mapping sensors M101, M102, and is capable of detecting the presence or absence of the transport objects W and their storage posture in the storage container 3.

[0114] In this embodiment, the mapping mechanism M uses the mapping sensor M102 to perform sensing to detect the protrusion of the transport object W stored in the storage container 3 before starting sensing to determine whether the transport object W is in a good or bad state using the two mapping sensors M101 and M102.

[0115] That is, in this embodiment, if the transport target W contained in the storage container 3 is at a position that protrudes from the storage container 3 more than its normal position during the mapping process, there is a risk that the two mapping sensors M101, M102 will collide with the transport target W. Therefore, while the load port 1 in the first embodiment has a sensor that is different from the mapping sensors M101, M102 of the mapping mechanism M as a protrusion sensor, in this embodiment, the mapping sensor M102 of the mapping mechanism M is used to detect the protrusion of the transport target W.

[0116] In the load port 201 of this embodiment, the mapping arm MT is configured to be movable between a non-mapping position where it is retracted further toward the transport chamber R than the frame 4 of the load port 201, and a mapping position where it is closer to the storage vessel 3 than the non-mapping position through the opening 41 of the frame 4.

[0117] 13(a), when the mapping arm MT is in the mapping possible position, the mapping sensors M101, M102 are disposed at a mapping position where they move downward while performing mapping. On the other hand, when the mapping arm MT is in the mapping impossible position, the mapping sensors M101, M102 are disposed at a jump-out detection position that is behind the mapping position. Note that in this embodiment, of the mapping sensors M101, M102, only the mapping sensor M102 is used to detect the jump-out of the transport target W stored in the storage container 3.

[0118] In the load port 201 of this embodiment, the mapping sensor M102 is moved downward from the mapping start height position while it is in the protruding detection position. As a result, as shown in FIG. 13(b), the transfer object W on the top slot 34 in the storage container 3 and the transfer object W on the second slot 34 from the top are not in the protruding position, and therefore the mapping sensor M102 does not detect the end faces Wa of these transfer objects W.

[0119] In contrast, as shown in FIG. 13(c), when the object W to be transported on the third slot 34 from the top in the storage container 3 is in a protruding position, the mapping sensor M102 detects the end face Wa of the object W to be transported.

[0120] In this embodiment, when the mapping sensor M102 is positioned at the protrusion detection position and moves downward from the mapping start height position, the detection range of the mapping sensor M102 must be set so that it does not detect the end face Wa of the transport object W that is in the normal position (not in the protruding position) on the slot 34, but detects the end face Wa of the transport object W that is in the protruding position on the slot 34, and the distance between the mapping position and the protrusion detection position is adjusted.

[0121] The mapping sensor M102 is moved to the mapping end height position, and after it is detected that no transport object W has protruded from each slot 34 within the storage container 3, the mapping arm MT is raised to the mapping start height position, as shown in Figure 14(a).

[0122] In this state, as shown in Fig. 14(b), when the mapping arm MT is moved to a mapping-enabled position closer to the containment vessel 3, the mapping sensors M101 and M102 are placed at the mapping position. Thereafter, as shown in Fig. 14(c), with the mapping sensors M101 and M102 at the mapping position, the mapping sensors M101 and M102 are moved downward from the mapping start height position to perform mapping processing. The mapping processing method is the same as the mapping processing method of the second embodiment.

[0123] As described above, according to the load port 201 of this embodiment, it is possible to map information regarding the storage state, including the presence or absence of the transport object W in each slot 34 in the storage vessel 3, using the mapping mechanism M having two mapping sensors M101, M102.

[0124] Furthermore, in the load port 201 of this embodiment, before starting sensing to determine whether the transport object W is in a good or bad state using the two mapping sensors M101 and M102, the mapping mechanism M uses the mapping sensor M102 to perform sensing to detect whether the transport object W stored in the storage container 3 has popped out.

[0125] According to the load port 201 of this embodiment, the mapping sensor M102 is used to detect the protrusion of the transport object W stored in the storage vessel 3, so there is no need to attach a separate sensor for detecting the protrusion of the transport object W. This makes it possible to reduce manufacturing costs.

[0126] The present invention is not limited to the above-described embodiment.

[0127] In the first embodiment, the discrimination unit MT determines that the transport object W is accommodated in a normal posture (horizontal posture) when the end face Wa of the transport object W is present in the detection target areas TA and TB of the two mapping sensors M1 and M2, but the method for determining that the transport object W is accommodated in a normal posture by the discrimination unit MT is arbitrary, and this is the same in the second and third embodiments.

[0128] For example, the discrimination unit MT may determine whether the transport object W is stored in a normal posture (horizontal posture) based on the interval between the signals ON output when the two mapping sensors M1 and M2 respectively detect the end faces Wa of the transport object W.

[0129] 15(a), consider a case where the object W to be transferred in the top slot 34 in the storage vessel 3, the object W to be transferred in the second slot 34 from the top, and the object W to be transferred in the third slot 34 from the top are accommodated in a normal posture (horizontal posture). In this case, when the mapping arm Mt descends from the mapping start height position and mapping is performed by the two mapping sensors M1 and M2, signals ON when the mapping sensors M1 and M2 each detect an end face Wa of the object W to be transferred are output at regular time intervals ta. Note that in FIGS. 15(a) and 15(b), the time when the mapping arm Mt is at the mapping start height position is set to 0 for the change in the signals of the mapping sensors M1 and M2.

[0130] 15(b), for example, consider a case where the object W to be transferred on the top slot 34 in the storage container 3 and the object W to be transferred on the third slot 34 from the top are accommodated in a normal posture (horizontal posture), and the right end portion of the object W to be transferred on the second slot 34 from the top is bent downward. In this case, when the mapping arm Mt descends from the mapping start height position and mapping is performed by the two mapping sensors M1 and M2, a signal ON when the mapping sensor M1 detects the end face Wa of the object W to be transferred is output at regular time intervals ta, whereas a signal ON when the mapping sensor M2 detects the end face Wa of the object W is no longer output at regular time intervals ta.

[0131] 15(b), after the end face Wa of the object W to be transferred on the top slot 34 in the storage container 3 has been detected, a time ta1 longer than the time ta has elapsed, and then the end face Wa of the object W to be transferred on the second slot 34 from the top has been detected. Also, after the end face Wa of the object W to be transferred on the second slot 34 from the top has been detected, a time ta2 shorter than the time ta has elapsed, and then the end face Wa of the object W to be transferred on the third slot 34 from the top has been detected.

[0132] In the second embodiment, the height position detection unit 112 detects the height position of the transport target object W (height position of the detection target area TA by the mapping sensor M101) based on the sensing information of the mapping sensor M101, but this is not limited to this.

[0133] Therefore, the height position detection unit 112 may detect the height position of the transport object W (height position of the detection target area TA by the mapping sensor M101) based on the sensing information of the mapping sensor M101, and may also detect the height position of the transport object W (height position of the detection target area TB by the mapping sensor M102) based on the sensing information of the mapping sensor M102.

[0134] In this case, the height position detection unit 112 detects the height position of one end side and the height position of the other end side of the transport object W, and the discrimination unit MT (good / bad discrimination unit 114) may determine whether the portion of the transport object W in the detection target area TA is at the normal height position by comparing the height position of the mapping sensor M101 on one end side of the transport object W with the normal height position of the transport object W on each slot 34, and may determine whether the portion of the transport object W in the detection target area TB is at the normal height position by comparing the height position of the mapping sensor M102 on the other end side of the transport object W with the normal height position of the transport object W on each slot 34. This is the same for the above three embodiments.

[0135] Furthermore, when the height position detection unit 112 detects the height position of one end side and the height position of the other end side of the transport object W, the discrimination unit MT (good / bad discrimination unit 114) may determine whether the transport object W is stored in a normal posture (horizontal posture) based on the difference between these height positions.

[0136] In the second embodiment, the normal position storage unit 113 stores the downward distance from the mapping start height position of the mapping arm Mt as the normal height position of the transport object W, but is not limited to this. The normal position storage unit 113 may also store the distance from an arbitrary position as the normal height position of the transport object W.

[0137] In the above first and second embodiments, the beam shapes emitted from the two mapping sensors M101, M102 are both strip-shaped extending along the end surface Wa of the transported object W, but it is also possible for only the beam shape emitted from one of the two mapping sensors M101, M102 to be strip-shaped extending along the end surface Wa of the transported object W.

[0138] In the first to third embodiments, 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 arbitrarily determined.

[0139] In the first to third embodiments, 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 object to be transported, etc.

[0140] In the first to third embodiments, the mapping sensor is not limited to a photoelectric sensor, and may be a proximity sensor or a laser distance measuring sensor.

[0141] In the first to third embodiments, 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.

[0142] In the first to third embodiments, the mapping process may be performed even after the transfer robot has placed the transfer object in the storage container on the load port.

[0143] In the first to third embodiments, the load port can also be applied to a transport device other than an EFEM.

[0144] In the first to third embodiments described above, for example, a plurality of load ports of the present invention may be arranged on the wall of a transfer chamber, and the load ports may be used 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 by a transfer robot arranged in the transfer chamber.

[0145] In the first to third embodiments, the number of load ports arranged on the wall surface of the transfer chamber may be one. In the above-described embodiments, the frame of the load port constitutes part of the outer wall of the transfer chamber, but the frame may be provided along the outer wall of the transfer chamber.

[0146] In the first to third embodiments, the glass substrates exemplified as the objects to be transported vary in bending not only depending 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 of the present invention can appropriately determine whether they are mounted in the correct orientation within the storage vessel. The thickness of the objects to be transported is not limited to that of the above embodiments and may be, for example, approximately 0.2 mm to 3 mm. Furthermore, the objects to be transported may be wafers, tape frame wafers, edge rings, reticles, liquid crystal transport objects, copper laminates, package substrates, printed circuit boards, culture plates, culture vessels, dishes, or petri dishes. In other words, the present invention can be applied to load ports that transfer objects housed in containers in various fields, such as semiconductors, liquid crystals, and cell culture.

[0147] In the first to third embodiments, the storage container that houses the objects to be transported may be an appropriate storage container depending on the size of the objects to be transported. An open-type storage container without a container door may also be used. The number of slots that support one object to be transported, the position of the slots within the storage container, or the shape of the slots may also be selected or changed as appropriate. For example, slots may be provided only at positions that support both side portions of the object to be transported, 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 configuring the mapping sensor to differentiate between the detection information of the slots detected by the mapping sensor and the detection information of the end face of the object to be transported, are also effective measures to avoid false detection.

[0148] In the above first to third embodiments, the load port is provided with a control unit, and the control unit controls the operation of each part, such as the movement of the load port door, but it is also possible to configure the operation of the load port to be 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-mentioned embodiments).

[0149] The first to third embodiments can be realized using a normal computer system, not a dedicated system. For example, a control unit that executes the above-described processes can be configured by installing a program for executing the above-described processes from a recording medium storing the program into a general-purpose computer. The means for supplying these programs is arbitrary. As described above, the programs can be supplied 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 program thus provided can then be started and executed under the control of the OS in the same way as other application programs, thereby executing the above-described processes.

[0150] 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]

[0151] 1 Loading Port 3. Containment vessel 4 frames 8 Load port door 31 Loading / unloading entrance 32 Container door 34 slots 41 Opening M mapping mechanism M1 Mapping sensor (first mapping sensor) M2 Mapping Sensor (Second Mapping Sensor) Mt Mapping Arm MT discriminator W Transported object

Claims

[Claim 1] a frame 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 of a storage container having slots that can accommodate the transport objects in multiple stages and that can open and close the opening of the frame; a mapping mechanism that maps information about a storage state including the presence or absence of the object to be transported in each slot in the storage container through the opening and the loading / unloading port, The mapping mechanism includes: two mapping sensors that move up and down integrally with or independently of the lifting and lowering movement of the load port door when opening and closing the opening, and that can detect the end face of the transport object by irradiating a detection wave toward the inside of the storage container; a determination unit that determines whether the accommodation state of the transport object is good or bad based on sensing information from the two mapping sensors.

Images