JP7583239B2 - Load port and mapping processing method for load port - Google Patents

Description

The present invention relates to a load port used in the semiconductor manufacturing process to transfer objects between FOUPs, which are storage containers 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, including the presence or absence of objects in each slot of the FOUP, and a mapping processing method for the load port.

For example, in the semiconductor manufacturing process, wafers are processed in clean rooms to improve yield and quality. In recent years, a "mini-environment system" has been introduced to further improve the cleanliness of only the local space around the wafer, and a means of transporting and processing the wafer has been adopted. In the mini-environment system, a load port is provided adjacent to the transport chamber, which constitutes part of the wall of a wafer transport chamber (hereinafter referred to as the transport chamber) that is substantially closed inside a housing, and a FOUP (Front-Opening Unified Pod), which is a storage container that stores objects to be transported such as wafers, is placed in the highly clean internal space. The load port is in close contact with the FOUP door and has the function of opening and closing the FOUP door. In the following, the door of the load port that can engage with the FOUP door and open and close the FOUP door is referred to as the "load port door".

Such a load port is a device for transferring objects to and from 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 in close contact with the FOUP door, the transfer robot arranged in the transfer chamber can take the object to be transferred from the FOUP into the transfer chamber, or store the object from the transfer chamber into the FOUP.

The load port is equipped with a mapping mechanism that can detect the presence or absence of a transport object and its storage orientation in the multi-stage slots provided within the FOUP. Conventional mapping mechanisms assume that the transport object is circular, and perform mapping processing using a transmissive optical sensor with a sensing line (transmitting 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), to detect the presence or absence of the transport object in each slot.

One example of a mapping mechanism is one in which a mapper equipped with a mapping sensor at its tip is configured to be movable between a non-mapping position, which is retracted from the frame of the load port toward the transport chamber, and a mapping position, which is closer to the inside of the FOUP than the non-mapping position, through an opening in the frame. The mapping mechanism is also configured to have a mapping movement unit (mapping arm) that supports the mapper, and to be able to detect (presence detection) whether or not a transport object is contained in each slot that constitutes the multi-stage slot by moving the mapping arm in the height direction while maintaining the mapper in the mapping position. In addition, detection of abnormal cross loading (cross detection), in which a transport object is supported in slots at different heights, and detection of double loading (double detection), in which two transport objects are supported overlapping each other in the same slot, are also performed simultaneously with the presence detection. The elevation movement of the mapping arm is performed integrally with or independent of the elevation movement of the load port door.

However, while the mapping process using the above-mentioned mapping mechanism can be performed smoothly and appropriately if the transported object is circular, it cannot be performed when the transported object has a shape other than circular, such as a rectangular panel or wafer.

In other words, in 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 to be transported from a substantially horizontal direction. If the object to be transported is circular, it is possible to secure a space between the outer periphery of the object to be transported and the inner surface of the FOUP on the FOUP door side. However, if the object to be transported is, for example, a so-called angular glass substrate, such as a square or rectangular object, the area occupied by the object to be transported in the FOUP increases compared to when it is circular, and it is therefore impossible or extremely difficult to secure a space between the outer periphery of the object to be transported and the inner surface of the FOUP for the sensor of the mapping mechanism to be able to enter sufficiently.

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 an 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 in the illumination area, the light-emitting unit irradiates light for imaging toward the transport object, and the imaging unit captures an image of the area illuminated by the light-emitting unit to obtain an image, making it possible to grasp the storage state of even a rectangular transport object based on the captured image.

JP 2019-102753 A

However, in the case of the above-mentioned mapping mechanism that illuminates light so that only one transported object is included within the illumination area, as the size of the rectangular transported object increases, the illumination area that occupies the entire transported object becomes smaller, and accurate cross detection may not be possible with just one captured image of one transported object. For example, in a case where a configuration is adopted in which a large object to be transported within a FOUP is supported by support parts such as slots provided at three locations, on the left, right, and center, within the FOUP, there are three types of cross abnormal mounting: i) a cross abnormal mounting in which the right and center are supported by support parts at the same height position, and only the left is not supported by a support part at the same height position as the right and center (supported by a support part at a different height position from the right and center, or supported by none of the support parts); ii) a cross abnormal mounting in which the left and center are supported by support parts at the same height position, and only the right is not supported by a support part at the same height position as the left and center (supported by a support part at a different height position from the left and center, or supported by none of the support parts); and iii) a cross abnormal mounting in which the left and right are supported by support parts at the same height position, and only the center is not supported by a support part at the same height position as the left and right (supported by a support part at a different height position from the left and center, or supported by none of the support parts). In particular, if the object to be transported is large and thin, it is expected that the object will be stored in a bent state due to its own weight as well as its thinness. Such bent loading, in which the object is stored in a bent state, can be considered a form of abnormal cross loading.

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 emitted from a light-emitting unit to obtain an image, and a process of identifying the storage state of the transport object based on the captured image. This requires more advanced processing and longer takt time than a mapping mechanism that can identify the storage state of the transport object by detecting a light-receiving state or a light-blocking state.

Patent Document 1 discloses an embodiment in which two mapping sensors are provided, each mapping sensor is configured to capture 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 based on the captured image acquired by the other mapping sensor. In this case, if the storage state is determined to be "good" based on both captured images, the storage state of the transport object is determined to be "good," and if the storage state is determined to be "poor" based on either captured image, the storage state of the transport object is 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 costs very high.

The present invention was made with an eye on these problems, and its main objective is to provide a load port and a mapping processing method for the load port that can accurately and precisely detect the storage state within a storage vessel, even for large objects to be transported that have a rectangular planar shape, without increasing the size of the entire device.

That is, the present invention comprises a flat frame arranged in an upright position and having an opening through which an object to be transported can pass in a substantially horizontal position, a load port door engageable with a container door capable of opening and closing an entrance/exit for the object to be transported of a storage container having slots capable of accommodating a plurality of objects to be transported in multiple stages and capable of opening and closing the opening of the frame, and a mapping mechanism that maps information regarding the storage state including the presence or absence of an object to be transported in each slot in the storage container through the opening and the entrance in an open state, wherein the mapping mechanism comprises a mapping arm that moves up and down integrally or independently with the lifting and lowering movement of the load port door when opening and closing the opening and is provided in the internal space of the transport chamber in which the load port door is provided , and a mapping mechanism that is supported at the same height position by the mapping arm and is capable of detecting an end face of the object to be transported without photographing or processing images, and that transmits a signal from the internal space of the transport chamber into the storage container to detect the end face of the object to be transported. The system is characterized in that it has three or more mapping sensors that receive signals reflected by the object to be transported , and a discrimination unit that discriminates whether the object to be transported is in a good or bad state based on sensing information from these three or more mapping sensors, and the detection target area by a first mapping sensor of the three or more mapping sensors arranged horizontally is set to a portion near one end of the entrance/exit of the storage container, the detection target area by a second mapping sensor is set to a portion near the other end of the entrance/exit, and the detection target area by a third mapping sensor is set to a portion in the widthwise center of the entrance/exit, and when a signal reflected by the object to be transported is received by any one mapping sensor but no signal is received by any one or all of the other mapping sensors, the discrimination unit determines that the object to be transported is abnormally loaded, indicating that it is not stored in a normal posture .

With this type of load port according to the present invention, it is possible to map information about the storage state, including the presence or absence of an object to be transported in each slot in the storage container, using the mapping mechanism. In particular, three or more mapping sensors are arranged side by side on a common mapping arm at a horizontal distance from each other, and the detection area for each mapping sensor is set to three locations in the storage container: the areas near both ends of the loading/unloading entrance and the center of the width of the entrance. Therefore, for example, if all three or more mapping sensors simultaneously detect an end face of the object to be transported, the discrimination unit can determine that the object to be transported is stored in a horizontal position based on the sensing information from these three or more mapping sensors. For example, if one mapping sensor detects an end face of the object to be transported but at least one of the other two mapping sensors does not detect the end face of the object to be transported, the discrimination unit can determine that the object to be transported is not stored in a horizontal position but is stored at an angle (cross abnormal loading) based on the sensing information from these three or more mapping sensors. Therefore, with the load port according to the present invention, even if the object is large and thin and has a rectangular planar shape and a straight end face that spans almost the entire width of the opening at the loading/unloading entrance of the storage vessel, the above-mentioned three or more mapping sensors can detect the vicinity of both ends and the center of the end face of the object facing the loading/unloading entrance, respectively, and the storage state of the object in the storage vessel can be detected accurately and precisely. Moreover, with the load port according to the present invention, the mapping mechanism can map information about the storage state, including the presence or absence of the object in each slot in the storage vessel, without taking pictures or processing images, and compared to an image processing system using a camera or the like, the processing for detecting the object can be speeded up and the system costs can be kept low. Here, in the present invention, a suitable example of a configuration in which information about the storage state, including the presence or absence of the object in each slot in the storage vessel is "mapped without taking pictures or processing images" can be 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 is good or bad)."

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

In the present invention, by performing sensing processing using sub-mapping sensors, which are the remaining two mapping sensors (mapping sensors among the three or more mapping sensors other than the main mapping sensor), at the same timing as sensing processing using one pre-set main mapping sensor among the three or more mapping sensors, it is possible to shorten the processing time required for the discrimination unit to discriminate whether the storage condition of the transported object is good or bad based on the sensing information from the three or more mapping sensors.

In this case, if a stepping motor is provided in the main mapping sensor and the presence or absence of an end face of the transport object and the thickness of the end face of the transport object are detectable based on the number of pulses of this stepping motor, and the sub-mapping sensor is set to be able to detect the presence or absence of the end face of the transport object, it is possible to quickly and reliably detect the presence or absence of the transport object, which is the detection object at the time of the sensing process, and detect cross abnormal loading, as well as whether or not the transport objects are stored in a state where multiple objects are stacked on top of each other (double abnormal loading) with the simplest configuration. Note that it is preferable to set the third mapping sensor, whose detection target area is the center part in the width direction of the loading/unloading entrance, as the main mapping sensor, and the first mapping sensor and the second mapping sensor, whose detection target areas are the areas near both ends of the loading/unloading entrance, as the sub-mapping sensors.

The present invention also relates to a mapping processing method for a load port that is used for delivering objects to be transported between a storage container capable of accommodating a plurality of objects to be transported in multi-stage slots and a transfer chamber, and that is equipped with a mapping mechanism that maps information regarding the storage state including the presence or absence of an object to be transported in each slot of the storage container, in which the mapping mechanism is equipped with three or more mapping sensors that are supported at the same height by a mapping arm provided in the internal space of the transfer chamber in which the load port door is provided , and have detection target areas in the vicinity of both ends of the load/unload entrance of the storage container and the central portion in the width direction of the entrance, and that are capable of detecting the object to be transported by emitting a signal from the internal space of the transfer chamber into the storage container and receiving a signal reflected by an end surface of the object to be transported in the storage container without photographing or processing the image , and that executes a mapping process in which, when determining whether the object to be transported is accommodated properly based on sensing information from these three or more mapping sensors, if a signal is not received from all or any of the other mapping sensors at the timing when a signal is received from any one mapping sensor, it is determined that the object to be transported is abnormally loaded, indicating that the object is not accommodated in a normal posture .

This type of mapping processing method provides various effects similar to those provided by the load port described above, and makes it possible to accurately and precisely detect the storage state of the object being transported inside the storage vessel, even if it is large and rectangular.

The present invention employs a novel technical idea of providing three or more mapping sensors spaced apart horizontally on a common mapping arm and using these three or more mapping sensors to detect three different locations on the end face of the transported object without photographing or processing the images, thereby avoiding the high cost and complex structure of the mapping mechanism and resulting in an increase in the size of the entire device, and providing a load port and a mapping processing method for the load port that can accurately and precisely detect the storage condition within a storage vessel, even for large, thin transported objects that are rectangular in planar shape.

FIG. 2 is a side view showing a schematic diagram of the relative positional relationship between an EFEM equipped with a load port according to an embodiment of the present invention and its peripheral devices. FIG. 2 is a plan view showing a simplified relative positional relationship shown in FIG. 1 . FIG. 2 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. FIG. 4 is a front view showing the load port according to the embodiment with some parts omitted. FIG. 4 is a diagram illustrating a detection target area of a mapping sensor in the present embodiment. 5 is a flowchart showing the operation procedure of the load port in the embodiment.

One embodiment of the present invention will be described below with reference to the drawings.

The load port 1 according to this embodiment is used, for example, in the semiconductor manufacturing process, and constitutes part of the wall of the transfer chamber 2 in a clean room as shown in Figs. 1 and 2, and is used to transfer the object W between the transfer chamber 2 and a storage container 3 such as a FOUP. The material of the object W may be glass, resin, SUS, or the like. 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 and thin object W (for example, a glass substrate with a planar size of 600 mm x 600 mm or 515 mm x 510 mm and a thickness of 0.2 mm to 2 mm) having a rectangular shape is used.

In this embodiment, as shown in FIG. 2, multiple load ports 1 (e.g., three load ports 1) 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 for the load port 1 (control unit 1C shown in FIG. 1) and a controller for the entire EFEM (control unit 2C shown in FIG. 1).

In the internal space 2S of the transfer chamber 2, a transfer robot 21 capable of transferring a transfer object such as a glass substrate between the storage container 3 on the load port 1 and the processing chamber R is provided. As shown in Figs. 1 and 2, the transfer robot 21 is provided with an arm 212 having a transfer object gripper 211 (hand) at the tip end of the arm 212, and a running part that supports the arm base constituting the base end of the arm 212 in a rotatable manner and runs in the width direction of the transfer chamber 2 (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 at its minimum and an extended state in which the arm length is longer than in the folded state. A transfer robot 21 in which a plurality of individually controllable hands 211 are provided in multiple stages in the height direction at the tip of the arm 212 can be applied. In addition, a transfer robot that does not have a running part and has a fixed installation position can be applied, or a sautetionary robot can be used as the transfer robot.

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 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 transfer target W are present in the internal space 2S of the transfer chamber 2, the downflow pushes the particles downward, making it possible to suppress adhesion of the particles to the surface of the transfer target W during transfer. In FIG. 1, the flow of gas forming the downflow in the transfer chamber 2 is shown diagrammatically by arrows. It is also possible to configure an EFEM by arranging appropriate stations such as a buffer station and an aligner on the side of the transfer chamber 2 or in the internal space 2S of the transfer chamber 2.

The internal space 2S of the transfer chamber 2 and the internal space 3S of the storage 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. Note that 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.

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 backward through the loading/unloading entrance 31, and a container door 33 that can open and close the loading/unloading entrance 31. As shown in FIG. 3, the storage container 3 has slots 34 that form multi-stage slots inside, and is configured to be able to accommodate the transport object W in each slot 34, and is configured to be able to take in and out the transport object W via the loading/unloading entrance 31. In this embodiment, in the storage container 3, as shown in FIG. 5(a), both side portions of the transport object W are supported by slots 34a and 34b at the same height, and the widthwise center portion of the transport object W is supported by slots 34c at the same height as the slots 34a and 34b. The upper surface of the container body 32 is provided with a flange portion 35 that is gripped by a device (e.g., OHT: Over Head Transport) that automatically transports the storage container 3 (see FIG. 1).

As shown in FIG. 1 and other figures, the load port 1 according to this embodiment includes a plate-shaped frame 4 that constitutes part of the wall of the transfer chamber 2 and has an opening 41 for opening the internal space 2S of the transfer chamber 2, a loading table 5 that is provided in a substantially horizontal position protruding forward from the frame 4, a seating and holding mechanism 6 that holds the storage container 3 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 of the frame 4, a door opening and closing mechanism 9 that opens the opening 41 of the frame 4 by moving the load port door 8 to a door open position retreated to the transfer chamber 2 side, and a mapping mechanism M that maps information about the storage state, including the presence or absence of the transfer object W in each slot 34 (34a, 34b, 34c) in the storage container 3 at the transfer object delivery position, when the opening 41 of the frame 4 is opened by the door opening and closing mechanism 9.

The frame 4 is arranged in an upright position and is a generally rectangular plate having an opening 41 large enough to communicate with the loading/unloading entrance of the storage container 3 placed on the loading table 5. The opening 41 of the frame 4 is shown diagrammatically in FIG. 1. In this embodiment, the load port 1 uses the frame 4 to form 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.

The mounting table 5 is provided on top of a horizontal base 50 (support) that is arranged in a generally horizontal position at a position slightly above the center of the height direction of the frame 4, and is capable of mounting the storage container 3 with the container body 32 facing the frame 4. As shown in FIG. 4, the mounting table 5 is provided with a number of protrusions 51 that protrude upward, and these protrusions 51 are engaged with holes (not shown) formed in the bottom surface of the storage container 3 to position the storage container 3 on the mounting table 5.

The seating retention mechanism 6 holds the storage container 3 on the mounting table 5 by hooking a locking claw 61 (see FIG. 4) on the mounting table 5 onto a locked portion (not shown) on the bottom surface of the storage container 3 to a fixed, locked state. In addition, in the load port 1 of this embodiment, the storage container 3 can be made to be able to be separated from the mounting table 5 by releasing the locked state of the locking claw 61 on the locked portion.

The traction mechanism 7 moves the storage container 3 on the loading table 5 in the forward and backward directions D between a seating position where the container body 32 is a predetermined distance away from the load port door 8 and a transport target object transfer position where the container body 32 is in close contact with the load port door 8. The traction mechanism 7 is configured using a slide rail (not shown) or the like that moves the loading table 5 forward and backward. The seating holding mechanism 6 and the traction mechanism 7 can also be considered as mechanisms provided on the loading table 5.

In FIG. 1, the state in which the storage vessel 3 is placed on the mounting table 5 is shown in a simplified manner as a state in which the bottom surface of the storage vessel 3 is in contact with the top surface of the mounting table 5. However, in reality, the storage vessel 3 is supported by a number of protrusions 51 that protrude above the top surface of the mounting table 5 engaging with bottomed holes formed in the bottom surface of the storage vessel 3, and the top surface of the mounting table 5 and the bottom surface of the storage vessel 3 do not come into contact with each other, and a specified gap is formed between the top surface of the mounting table 5 and the bottom surface of the storage vessel 3.

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

The load port door 8 can be moved between a fully closed position where the opening 41 of the frame 4 is sealed, a door open position where the door is retracted toward the transfer chamber 2 from the fully closed position, and a fully open position where the opening space of the opening 41 is fully opened backward. In FIG. 1, the load port door 8 is shown in the door open position in order to show the external appearance of the load port door 8 and the mapping mechanism M described later. In actual operation, the load port door 8 is positioned in the door open position when the storage container 3 is moved to the transfer object delivery position (the position where the container body 32 is in close contact with the load port door 8) and the container door 33 is engaged and held. In other words, it is essential to operate the EFEM and the transfer chamber 2 in such a way that the inside of the EFEM and the transfer chamber 2 are not opened to the outside space. The load port door 8 has an engagement portion 81 that can adsorb and hold the container door 33 of the storage container 3 (see FIG. 4), and is configured to be movable integrally with the container door 33 between the fully closed position, the door open position, and the fully open position while maintaining the engagement state with the container door 33. The movement path of the load port door 8 between the fully closed position and the fully open position consists of a path (horizontal path) in which the load port door 8 in the fully closed position is moved toward the transfer chamber 2 to the door open position while maintaining its height position, and a path (vertical path) in which the load port door 8 in the door open position is moved downward to the fully open position while maintaining its front-to-back position. The container door 33 held by the load port door 8 positioned in the door open position is positioned together with the load port door 8 at a position rearward of the frame 4 (a position completely separated from the container body 32 and disposed in the internal space 2S of the transfer chamber 2) so that the load port door 8 positioned in the door open position can move in both the vertical and horizontal directions.

Such movement of the load port door 8 is realized 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 container 3 to the transfer chamber 2 through the opening of the open frame 4. The door opening/closing mechanism 9 is configured, for example, using 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 vertical direction H, and moves the load port door 8 in the forward/backward direction D and the vertical direction H by operating a drive source (not shown) such as an actuator. Note that an embodiment in which an actuator for forward/backward movement and an actuator for vertical movement are separately provided may be used, but in terms of reducing the number of parts, an embodiment in which the load port door 8 is moved forward/backward and vertically using a common actuator as a drive source is superior.

The load port door 8 of this embodiment is equipped with a connection switching mechanism 82 that releases the engagement state (latched state) between the container door 33 and the container body 32 to make the container door 33 removable from the container body 32 (unlatched state) (see FIG. 4). The load port 1 of this embodiment can also be equipped with a bottom purge section that is provided on the mounting table 5 and can inject an environmental gas (also called a purge gas, and in this embodiment, mainly nitrogen gas or dry air) into the storage container 3 from the bottom side of the storage container 3, thereby replacing the gas atmosphere in the storage container 3 with the environmental gas. The bottom purge section is mainly composed of a plurality of nozzles (not shown) provided at predetermined positions on the mounting table 5, and the plurality of nozzles function as bottom purge injection nozzles that inject a predetermined environmental gas and bottom purge discharge nozzles that discharge the gas atmosphere in the storage container 3. These plurality of nozzles can be connected in a state of being fitted into an inlet and an outlet (both not shown) provided at the bottom of the storage container 3. The purging process can be performed by supplying environmental gas from the bottom purge injection nozzle through the inlet into the internal space 3S of the storage vessel 3, and discharging the gas atmosphere of the internal space 3S of the storage vessel 3 from the bottom purge discharge nozzle through the discharge port (this gas atmosphere is air or a low-purity environmental gas other than air for a predetermined time from the start of the purging process, and after the predetermined time has elapsed, it is a high-purity environmental gas filled in the internal space 3S of the storage vessel 3).

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

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

The three mapping sensors M1, M2, and M3 of the mapping mechanism M can be classified into a first mapping sensor M1, whose detection target area TA is the area near one end 31a of the loading/unloading entrance 31 of the storage container 3, a second mapping sensor M2, whose detection target area TB is the area near the other end 31b of the loading/unloading entrance 31, and a third mapping sensor M3, whose detection target area TC is a predetermined area between the detection target area TA by the first mapping sensor M1 and the detection target area TB by the second mapping sensor M2 in the loading/unloading entrance 31, as shown in Figures 3 and 5(a). The detection target areas TA, TB, and TC of each of these mapping sensors M1, M2, and M3 are irradiation areas of sensor light shown in circles as shown in Figure 5(a), and are particularly irradiation areas with a diameter approximately equal to the thickness of one transport object W to be detected. As can be seen from the figure, these three detection target areas TA, TB, and TC are at the same height position. The detection area of the mapping sensor can be changed as appropriate depending on the thickness of the transport target object W. The position of the mapping sensor (sensor position) can also be configured to be adjustable in the left-right width direction.

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

The detection target area TC of the third mapping sensor M3 is preferably the midpoint (the widthwise center of the entrance 31) between the detection target area TA by the first mapping sensor M1 and the detection target area TB by the second mapping sensor M2, but in this embodiment, it is an area that is a predetermined distance closer to the detection target area TA by the first mapping sensor M1 than the widthwise center of the entrance 31. This is a measure to avoid interference between the pop-out sensor (not shown) and the third mapping sensor M3 in the load port 1 according to this embodiment. In other words, if the transport object W contained in the storage container 3 during the mapping process is in a position that pops out from the storage container 3 rather than the normal position, there is a risk that the mapping sensor M1 will collide with the transport object W. In order to avoid this situation, when a pop-out sensor (for example, a pop-out sensor with the irradiation axis of the detection wave directed in the height direction, not shown) that detects the pop-out transport object W is provided in the widthwise center of the entrance 31, it is necessary to avoid interference between the pop-out sensor and the third mapping sensor M3. In this embodiment, the detection target area TC of the third mapping sensor M3 is not the widthwise center of the loading/unloading entrance 31, but is an area included in the widthwise central portion of the loading/unloading entrance 31. In addition, by setting the detection target area TC of the third mapping sensor M3 to an area closer to the detection target area TA of the first mapping sensor M1 by a predetermined distance from the widthwise center of the loading/unloading entrance 31, the detection target area TC of the third mapping sensor M3 can be set at a position that avoids the slot 34c that supports the widthwise central portion of the transport object W. In other words, the detection target area TC of the third mapping sensor M3 is set so that the sensor light for detecting the presence or absence of the transport object W does not irradiate the slot 34c, similar to the detection target areas TA and TB of the first mapping sensor M1 and the second mapping sensor M2.

As shown in FIG. 3, the mapping arm M4 is provided with a long arm body M41 that extends at least in the horizontal direction, and supports three mapping sensors M1, M2, M3 in a fixed state at predetermined positions spaced apart from each other in the horizontal direction on the arm body M41. Each mapping sensor M1, M2, M3 is supported in a position in which its tip faces forward and protrudes forward from the mapping arm M4. In this embodiment, as shown in FIG. 3, the direction in which the three mapping sensors M1, M2, M3 are lined up (the mapping sensor parallel direction ML shown 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 carry-in/out entrance 31. In addition, the mounting and fixing positions of the mapping sensors M1, M2, M3 relative to the mapping arm M4 are set so that a predetermined gap (for example, 56 mm) is formed between each tip of the mapping sensors M1, M2, M3 and the end face Wa of the transport object W. In some cases, it may be acceptable to place the transport target W in the storage container 3 at a position that is shifted (out of position) by ±several mm from the normal position. In such a case, the mapping sensors M1, M2, and M3 are configured to be changeable in position to accommodate the shift, thereby ensuring an appropriate separation distance between the tips of the mapping sensors M1, M2, and M3 and the end surface Wa of the transport target W. In the load port 1 of this embodiment, the mapping arm M4 is attached to a part that constitutes the door opening/closing mechanism 9 (see FIG. 1). Therefore, the mapping arm M4 also operates together with the lifting and lowering operation of the load port door 8 by the door opening/closing mechanism 9. 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 adopt a configuration in which the mapping arm M4 is attached directly to the upper end of the load port door 8 or via another part. Even in such a configuration, the entire mapping mechanism M moves up and down in the same direction as the load port door 8.

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

The discrimination unit M5 discriminates whether the transport object W is in a good or bad state based on the sensing information from the three mapping sensors M1, M2, and M3. Here, each mapping sensor M1, M2, and M3 emits a beam (ray light) as a signal and detects the presence or absence of the transport object W in the detection target area TA, TB, and TC based on whether or not the signal is received, and the trajectory of the beam (ray light line) can be regarded as the detection line. That is, the detection line during the mapping process consists of a straight line line during signal transmission that extends from the internal space 2S side of the transport chamber 2 toward the end face Wa of the transport object W, and a straight line during signal reception that extends from the end face Wa of the transport object W toward the internal space 2S side of the transport chamber 2, as shown by the straight arrow in FIG. 3. During the mapping process, when a signal (beam) is emitted forward from the transmitter of each mapping sensor M1, M2, M3, 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, M3, 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 such a signal is received, it is possible to sequentially detect whether the end face Wa of the transport object W is present in the detection target area TA, TB, TC of each mapping sensor M1, M2, M3.

Then, when all mapping sensors M1, M2, M3 receive signals simultaneously or approximately simultaneously (signal ON; reflected light is received), that is, when the end surface Wa of the transported object W is present in the detection areas TA, TB, TC of all mapping sensors M1, M2, M3 as shown in Figure 5 (a), the discrimination unit M5 determines that the transported object W is accommodated in a normal posture (horizontal posture); when no signal is received from all or one of the other mapping sensors at the timing when a signal is received by any one of the three mapping sensors M1, M2, M3 (signal OFF; reflected light is not received), for example, when the end surface Wa of the transported object W is not present in the detection area TB of the second mapping sensor M2 as shown in Figure 5 (b), the discrimination unit M5 determines that the transported object W is not accommodated in a normal posture (cross abnormal mounting); and when no signal is received from all mapping sensors M1, M2, M3, the discrimination unit M5 determines that the transported object W is not accommodated. In this way, the discrimination unit M5 not only discriminates whether the transport object W is accommodated or not, but also discriminates whether the transport object W is accommodated in a horizontal position or is abnormally cross-mounted (not horizontally mounted) depending on whether the three mapping sensors M1, M2, and M3 arranged in a horizontal line detect (signal ON) simultaneously or substantially simultaneously. In particular, as shown in FIG. 5B, when a large transport object W is accommodated in a bent state due to its own weight or thinness, etc., if the degree of bending is large, at the timing when one of the three mapping sensors M1, M2, and M3 receives a signal, all or one of the other mapping sensors do not receive a signal, and based on this detection information, the discrimination unit M5 determines that the transport object W is not accommodated in a normal position (horizontal position). The bent mounting can be regarded as one aspect of abnormal cross mounting. That is, if the object to be transported has a large (thick) thickness and is close to a rigid body, it will not bend, so if the discrimination unit M5 determines that such an object to be transported is not stored in a horizontal position, the object to be transported is stored in a generally inclined position (a position in which the overall linear shape in the width direction is maintained). On the other hand, as shown in FIG. 5B, if the object to be transported W has a small (thin) thickness, when the discrimination unit M5 determines that the object to be transported is stored in a position in which at least a part of the object to be transported is bent, the object to be transported is stored in a generally inclined position (a position in which the overall linear shape in the width direction is maintained). On the other hand, as shown in FIG. 5B, if the object to be transported W has a small (thin) thickness, when the discrimination unit M5 determines that the object to be transported is stored in a generally inclined position, the object to be transported is stored in a generally inclined position. The abnormal cross loading shown in FIG. 5B is a state in which the left end vicinity region and the width direction center portion of the object to be transported W are supported by the slots 34a and 34c at the same height position, while the object to be transported W is not supported by the slots 34b at the same height position as the slots 34a and 34c, and the right end vicinity region of the object to be transported W that is not supported by the slots 34b is floating in the air. In addition, for example, a state in which the region 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, 34c at the same height position, while the region 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, 34c (the region of the object W to be transported near the right end as viewed from the paper surface is not floating in the air), is also one form of cross abnormal mounting.
In this way, the mapping mechanism M of this embodiment determines whether the storage condition of the transport object W is good or bad by each mapping sensor M1, M2, M3 having a predetermined detection area TA, TB, TC detecting the end face Wa of the transport object W.

In addition, in the mapping mechanism M of this embodiment, the thickness of the transport object W is also calculated based on the duration of signal reception by the mapping sensors M1, M2, and M3 (signal ON duration). When the mapping arm M4 is raised and lowered by the 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, M2, and M3 (signal ON duration). In this embodiment, in order to improve processing efficiency, only the signal ON duration of the third mapping sensor M3 is measured, and the signal ON duration of the other mapping sensors (first mapping sensor M1, second mapping sensor M2) is not measured. This is because it is possible to determine whether the transport object W is stored in a state where multiple transport objects W are stacked on top of each other from the thickness at least one point of the stored transport object W.

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

The storage unit stores control procedures (operation sequences) according to the type of processing to be performed by the load port 1. In other words, the storage unit stores a specific operation program. In this embodiment, the program is stored as an executable program on a non-transitory computer-readable recording medium (such as a hard disk).

The ROM is composed of a hard disk, EEPROM, flash memory, etc., and is a recording medium that stores the CPU's operating programs, etc. The RAM functions as the CPU's work area, etc. The I/O port, for example, outputs control signals output by the CPU to each part and mechanism, and supplies information from various sensors to the CPU.

The CPU constitutes the core of the control unit 1C and executes the operation programs stored in the ROM. The CPU controls the operation of the load port 1 in accordance with the programs stored in the memory unit.

Next, the method of use (particularly the mapping processing method) and operation of the load port 1 according to this embodiment will be explained with reference to FIG. 6, which shows the operation flow.

First, the storage container 3 is transported to above the load port 1 by an automatic storage container transport device such as an OHT that operates on a linear transport line (traffic line) extending along the common wall surface 2F on which the load port 1 is arranged in the transport chamber 2, and is placed on the placement table 5. In the load port 1 according to this embodiment, the control unit 1C executes a seating and holding process St1 in which the seating and holding mechanism 6 holds the storage container 3 on the placement table 5 (see FIG. 6). The specific process of the seating and holding process St1 in this embodiment is a process in which the locking claw 61 on the placement table 5 is hooked onto a locked portion (not shown) provided on the bottom surface of the storage container 3 or the bottom surface of the frame cassette C to lock it. This allows the storage container 3 or the frame cassette C to be placed and fixed at a predetermined seating position on the placement table 5. When the storage container 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 container 3.

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 is placed at a predetermined position on the loading table 5 using a seating sensor (not shown) that detects whether the storage container 3 is placed at a predetermined position on the loading table 5.

Following the seating and holding process St1, in the load port 1 of this embodiment, the control unit 1C causes the towing mechanism 7 to move the loading table 5 backward from the seating position toward the frame 4 to the transfer position of the transport object (rear towing process St2). This rear towing process St2 makes it possible to connect (dock) the container door 33 to the load port door 8, which is waiting in advance in a fully closed position, and hold it 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 described above, and is held in a tight contact state.

In the load port 1 of this embodiment, when the storage vessel 3 is placed at a seating position on the placement table 5, the control unit 1C detects that the bottom surface of the storage vessel 3 has pressed against, for example, a pressure sensor provided on the placement table 5, and this triggers the control unit 1C to give a drive command (signal) to cause the bottom purge injection nozzle and bottom purge discharge nozzle provided on the placement table 5 to advance above the upper surface of the placement table 5. As a result, these nozzles (bottom purge injection nozzle, bottom purge discharge nozzle) are respectively connected to the inlet and outlet of the storage vessel 3, making it possible to carry out the purging process.

In the load port 1 of this embodiment, the control unit 1C issues a drive command to execute a purging process St3 for the internal space 3S of the storage vessel 3. This purging process St3 is a process in which a predetermined environmental gas is supplied from the bottom purge injection nozzle via the injection port to the internal space 3S of the storage vessel 3, and the gas that had been retained in the internal space 3S of the storage vessel 3 until then is discharged from the bottom purge discharge nozzle via the discharge port. This purging process St3 fills the internal space 3S of the storage vessel 3 with environmental gas, and the moisture concentration and oxygen concentration in the storage vessel 3 are each reduced to below a predetermined value in a short period of time, thereby making the surrounding environment of the transported object W in the storage vessel 3 a low-humidity and low-oxygen environment.

It is possible to use a storage vessel 3 that has been purged before being placed on the loading table 5, and the purging process St3 may be performed on such a storage vessel 3, or it is also possible to choose not to perform the purging process St3.

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

Following the unlatch process St4, in the load port 1 of this embodiment, the control unit 1C executes a process (door opening process St5) in which the door opening/closing mechanism 9 moves the load port door 8 backward from the fully closed position to the door open position, thereby opening the opening 41 of the frame 4. Specifically, the control unit 1C causes the door opening/closing mechanism 9 to move the load port door 8 a predetermined distance along the above-mentioned horizontal path 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 by the engagement portion 81. Therefore, the door opening process St5 causes the loading/unloading entrance 31 of the storage container 3 to be in an open state, similar to the opening 41 of the frame 4.

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

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 three mapping sensors M1, M2, and M3 move from the mapping start height position to a position lower than the lowest slot 34 (mapping end height position) while being maintained at an appropriate position where the mapping process St6 can be performed. The control unit 1C performs a sensing process to detect the presence or absence of signal reception for each of the mapping sensors M1, M2, and M3 through the above procedure. In this embodiment, the sensing process is performed by the remaining two mapping sensors (the first mapping sensor M1 and the second mapping sensor M2) at the same timing as the sensing process by one mapping sensor (the third mapping sensor M3 in this embodiment) that is preset among the three mapping sensors M1, M2, and M3. In this way, in this embodiment, the third mapping sensor M3 functions as the main mapping sensor, and the first mapping sensor M1 and the second mapping sensor M2 function as sub-mapping sensors that operate in synchronization with the main mapping sensor. The control unit 1C executes a mapping process St6 in which the discrimination unit M5 determines whether the storage condition, including the presence or absence of the transport object W, is good or bad for each slot 34 based on the detection signal generated by the sensing process.

The specific method of determination in the determination unit M5 is as described above, and the mapping process St6 can identify whether the state of the transport object W in the slot 34 being determined is normal loading, cross abnormal loading, or no loading (empty slot). In addition, in the load port 1 of this embodiment, the control unit 1C calculates the thickness of the transport object W based on the duration of signal reception (signal ON duration) by the mapping sensor (the third mapping sensor M3, which is the main mapping sensor in this embodiment) in the mapping process St6 using the mapping mechanism M, and determines whether the transport object W is stored in a state where multiple sheets are stacked on top of each other based on the calculation result by the determination unit M5. In other words, if the duration of signal reception is equal to or longer than a predetermined time, the determination unit M5 determines that the transport object W is stored in a state where multiple sheets are stacked on top of each other (double abnormal loading).

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

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

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

That is, according to the load port 1 of this embodiment, the three mapping sensors M1, M2, and M3 are arranged in a horizontal line spaced apart from each other on a common mapping arm M4, and the detection target areas TA, TB, and TC of each mapping sensor M1, M2, and M3 are set to three locations in total: the areas near both ends 31a and 31b of the loading/unloading entrance 31 of the storage container 3, and the central area in the width direction of the loading/unloading entrance 31. Therefore, when all three mapping sensors M1, M2, and M3 simultaneously detect the end surface Wa of the transport target object W, the discrimination unit M5 determines whether these three mapping sensors Based on the sensing information from M1, M2, and M3, it can be determined that the transport object W is accommodated in a horizontal position. If at least one of the other two mapping sensors does not detect the end face Wa of the transport object W at the timing when one mapping sensor detects the end face Wa of the transport object W, the discrimination unit M5 can determine that the transport object W is not accommodated in a horizontal position but is accommodated in an oblique position (cross abnormal mounting including bending mounting) based on the sensing information from these three mapping sensors M1, M2, and M3. Therefore, according to the load port 1 of this embodiment, it is possible to accurately and precisely detect the accommodation state in the storage container 3 even if the transport object W has a rectangular planar shape and is large and thin. Moreover, with the load port 1 of this embodiment, it is possible to map information on the accommodation state, including the presence or absence of the transport object W in each slot 34 in the storage container 3, by the mapping mechanism M without taking pictures or processing images. Compared to an image processing system using a camera or the like, it is possible to speed up the process of detecting the transport object W and to keep the cost of the system low.

In addition, with the load port 1 according to this embodiment, the mapping arm M4 moves up and down together with the load port door 8 when opening and closing the opening 41 of the frame 4. This means that there is no need for a mechanism for independently moving the mapping arm M4 up and down, and yet it is possible to execute the mapping process St6 by the mapping mechanism M at the same time as the process for opening and closing the opening 41, thereby improving the operating rate in semiconductor manufacturing.

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

Furthermore, in the load port 1 according to this embodiment, the main mapping sensor (third mapping sensor M3) is set to be able to detect the presence or absence of the end face Wa of the transport object W and the thickness of the end face Wa of the transport object W, and the sub-mapping sensors (first mapping sensor M1, second mapping sensor M2) are set to be able to detect only the presence or absence of the end face Wa of the transport object W. Therefore, even with the simplest configuration, in addition to detecting the presence or absence of the transport object W and cross abnormal loading at the time of the sensing process by each mapping sensor M1, M2, M3, it is also possible to quickly and reliably detect whether the transport object W is stored in a state where multiple objects W are stacked on top of each other (double abnormal loading).

In addition, the mapping processing method for the load port 1 adopted in this embodiment provides the same effects as those provided by the load port described above, and can improve the operating rate in semiconductor manufacturing.

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

Also, either the first mapping sensor or the second mapping sensor, whose detection target area is the 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, it is possible to arbitrarily determine which of the three or more mapping sensors to set as the main mapping sensor.

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

The mapping sensor is not limited to a photoelectric sensor, but may also be a proximity sensor or a laser ranging sensor.

In addition, in the present invention, the mapping mechanism can be configured such that the mapping sensor is supported by a mapping arm so that it can be rotated horizontally or approximately horizontally, and the mapping sensor can be switched between a mapping position and a non-mapping position by moving it around the rotation axis. Alternatively, a configuration can 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 can be adopted in which the entire mapping arm slides toward the storage vessel to move the mapping sensor toward the storage vessel and position it at the mapping position.

The system may also be set to perform mapping processing after the transport robot has placed the transported object in the storage container on the load port.

The load port of the present invention can also be applied to transport devices other than EFEM.

In addition, for example, it is possible to arrange multiple load ports according to the present invention on the wall of a transfer chamber and use them as part of a sorter device that can exchange objects to be transferred between storage containers placed on the loading tables of each load port by a transfer robot arranged in the transfer chamber.

There may be only one load port arranged on the wall of the transfer chamber. In the above embodiment, an example was given in which the frame of the load port constitutes part of the outer wall of the transfer chamber, but the frame may also be provided along the outer wall of the transfer chamber.

The glass substrates exemplified as the transport objects in the above-mentioned embodiments bend differently depending on not only their thickness but also their composition. Such glass substrates, particularly thin glass substrates with a thickness of less than 0.4 mm, are prone to bending, but the mapping mechanism of the load port according to the present invention can appropriately determine whether or not they are mounted in the correct position inside the storage container. The transport object may be a reticle, a liquid crystal transport object, a culture plate, a culture container, a dish, or a petri dish. In other words, the present invention can be applied to a load port that delivers transport objects contained in containers in various fields such as semiconductors, liquid crystals, and cell culture.

The storage container that holds the transport object may be an appropriate storage container according to the size of the transport object, etc. An open type storage container without a container door may also be used. In addition, the number of slots that support one transport object, the position of the slots in the storage container, or the shape of the slots may be appropriately selected or changed. For example, slots may be provided only at positions that support both side portions of the transport object, or at positions that overlap the detection target area of the mapping sensor in the height direction. Making the slots undetectable by the mapping sensor, or configuring the slots so that even if the slots are detected by the mapping sensor, the detection information can be differentiated from the detection information when the end face of the transport object is detected is also an effective measure to avoid erroneous detection.

In the above embodiment, the load port is equipped 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 embodiment).

The above-mentioned control unit can be realized using a normal computer system, not a dedicated system. For example, a control unit that executes the above-mentioned processes can be configured by installing a program for executing the above-mentioned processes from a recording medium storing the program on a general-purpose computer. The means for supplying these programs are arbitrary. In addition to being able to supply them via a specific recording medium as described above, they may also be supplied 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 may be provided by superimposing it on a carrier wave via network communication. The above-mentioned processes can then be executed by starting up the program provided in this way and executing it under the control of the OS in the same way as other application programs.

The specific configuration of each part is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention.

1...load port 3...containment vessel 32...vessel door 34...slot 4...frame 41...opening 8...load port door M...mapping mechanism M1...first mapping sensor (sub-mapping sensor)
M2: Second mapping sensor (sub-mapping sensor)
M3: Third mapping sensor (main mapping sensor)
M4: Mapping arm M5: Discrimination unit W: Transport object

Claims (3)

a flat frame disposed in an upright position and having an opening through which the object to be conveyed can pass in a substantially horizontal position;
a load port door that can be engaged with a container door that can open and close an entrance for the objects to be transported in a storage container having slots that can accommodate the objects to be transported in multiple stages and that can open and close the opening of the frame;
a mapping mechanism that maps information regarding a storage state including the presence or absence of the object to be transported in each of the slots in the storage container through the opening and the loading/unloading entrance that are in an open state,
The mapping mechanism includes:
a mapping arm that moves vertically integrally with or independently of the lifting and lowering movement of the load port door when opening and closing the opening, and that is provided in an internal space of a transfer chamber in which the load port door is provided;
three or more mapping sensors supported at the same height by the mapping arm and capable of detecting an end surface of the transported object without photographing or processing an image, the mapping sensors emitting a signal from the internal space into the storage vessel and receiving a signal reflected by an end surface of the transported object in the storage vessel;
a discrimination unit that discriminates whether the storage state of the transport object is good or bad based on sensing information from the three or more mapping sensors,
a detection target area by a first mapping sensor among the three or more mapping sensors arranged side by side in a horizontal direction is set to a portion of the storage container near one end of the loading/unloading entrance, a detection target area by a second mapping sensor is set to a portion of the storage container near the other end of the loading/unloading entrance, and a detection target area by a third mapping sensor is set to a central portion in a width direction of the loading/unloading entrance,
a sensing process is performed by a sub-mapping sensor, which is a mapping sensor other than the main mapping sensor, among the three or more mapping sensors, at the same timing as a sensing process by a preset main mapping sensor among the three or more mapping sensors;
A stepping motor is provided for the main mapping sensor;
setting the presence or absence and thickness of the end face of the object to be conveyed to be detectable based on the number of pulses of the stepping motor, and setting the presence or absence of the end face of the object to be conveyed to be detectable by the sub-mapping sensor;
A load port characterized in that, when the signal reflected by the transported object is not received by all or one of the other mapping sensors at the same time that the signal reflected by the transported object is received by any one of the mapping sensors, the discrimination unit determines that the transported object is abnormally loaded, indicating that the object is not accommodated in a normal posture. the object to be conveyed is a rectangular substrate,
The mapping sensors are set in a direction parallel or approximately parallel to an extension direction of the end surface of the transport object,
2. The load port according to claim 1, wherein the mapping mechanism determines whether the object is in a good or bad state by detecting an end face of the object by each mapping sensor having a predetermined detection area. 1. A mapping processing method for a load port that is used for transferring a plurality of objects to be transferred between a storage container capable of storing a plurality of objects in multi-stage slots and a transfer chamber, the load port including a mapping mechanism that maps information regarding a storage state including the presence or absence of the objects to be transferred in each slot of the storage container, the method comprising the steps of:
the mapping mechanism includes three or more mapping sensors that are supported at the same height position by a mapping arm provided in the internal space of a transfer chamber in which the door of the load port is provided, and have detection target areas in the vicinity of both ends of the loading/unloading entrance of the storage container for the transfer object and in the central area in the width direction of the loading/unloading entrance, and are capable of detecting the transfer object by emitting a signal from the internal space into the storage container without photographing or image processing and receiving a signal reflected by an end surface of the transfer object in the storage container , and performs sensing processing by a sub-mapping sensor, which is a mapping sensor other than the main mapping sensor, among the three or more mapping sensors, at the same timing as sensing processing by one main mapping sensor that is preset among the three or more mapping sensors ,
The main mapping sensor is set to be capable of detecting the presence or absence and thickness of an end face of the transport object based on the number of pulses of a stepping motor provided in the main mapping sensor, and the sub-mapping sensor is set to be capable of detecting the presence or absence of an end face of the transport object, and a mapping process is executed to determine whether the transport object is in a good or bad state based on sensing information from these three or more mapping sensors,
A mapping processing method for a load port, characterized in that when the reflected signal is not received from all or one of the other mapping sensors at the same time that the reflected signal is received by any one of the mapping sensors, it is determined that the object to be transported is a cross-abnormal loading, indicating that the object is not accommodated in a normal posture.

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