JP5529522B2 - Substrate storage state detection device and substrate storage state detection method - Google Patents

Description

  The present invention relates to a substrate storage state detection device and a substrate storage state detection method.

  When transporting a thin flat plate-like substrate (hereinafter referred to as a substrate) such as a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disk, etc. at a predetermined location such as a manufacturing factory, It is usually performed to transfer between processes after being stored in each slot (shelf) provided in a substrate storage container (hereinafter referred to as a cassette). In each process, the substrates are unloaded and transferred one by one from each slot of the cassette, subjected to predetermined substrate processing, and then loaded into the original slot.

  An example of the substrate unloading system in which the substrate is unloaded from each slot of the cassette as described above is a FOUP (Front-Opening Unified Pod) system in a clean room of a semiconductor manufacturing factory. The FOUP system embodies a local cleaning technology called the mini-environment method in response to demands for energy saving and ensuring flexibility for multi-product low-volume production. Note that the mini-environment method does not increase the cleanliness of the entire clean room, but rather increases the cleanliness around the equipment exposed to the environment with the wafers bare, creating a locally clean environment. It is a method.

  FIG. 14 is a diagram for explaining the FOUP system. The FOUP system is a FOUP (Front Opening), which is a front-opening and sealed cassette in which a wafer (semiconductor substrate) 100 is accommodated in a clean room of a semiconductor manufacturing factory having a plurality of FFU (Fan Filter Units) 101 provided on the ceiling. -Opening Unified Pod) 102, a FOUP transport device 103 for placing the cassette 102 and transporting it to the mini-environment housing 104, the mini-environment housing 104, and the mini-environment housing 104. , A robot 109 that unloads the wafers 100 one by one from the cassette 102 that has been transported by the FOUP transport device 103 and transports the wafers 100 to a predetermined position of the semiconductor manufacturing apparatus 105, a robot control device 110 that controls the operation of the robot 109, and a robot A predetermined substrate processing is performed on the wafer 100 transferred by 109. And a semiconductor manufacturing apparatus 105 that performs (heat treatment, diffusion treatment, etc.). An FFU (Fan Filter Unit) 106 is provided on the ceiling of the mini-environment housing 104, and this FFU 106 realizes a mini-environment that makes the inside of the housing more clean than the outside of the housing. In addition, on both side surfaces of the mini-environment housing 104, a door 107 for introducing the cassette 102 from the outside of the housing into the housing, and a wafer 100 unloaded from the cassette 102 by the robot 109 from the inside of the housing. And a door 108 for transporting to 105.

  By the way, due to vibration or the like that occurs during the conveyance of the cassette 102 by the FOUP conveyance device 103, the wafer 100 may be displaced in the cassette 102, that is, the wafer 100 may jump out from a predetermined storage position of the cassette 102. Therefore, the robot controller 110 needs to detect and grasp in advance the storage state of the wafer 100 in the cassette 102 before unloading the wafer 100 from the cassette 102.

  By the way, as a technique relating to detection of protrusion of a wafer, for example, there are techniques as described in Patent Documents 1 and 2 below.

  In Patent Document 1, a light projecting head and a light receiving head are vertically arranged opposite to each other on the opening surface side of a cassette, and a screen-like light beam is formed between both heads, which is blocked by a wafer protruding from the cassette. It is disclosed to detect popping out based on the above.

  In Patent Document 2, the distance measurement sensor installed in the wafer transfer device measures the distance between the wafer transfer device and the wafer in the cassette or on the boat, detects the positional deviation of the wafer, and the distance is within a certain range. It is disclosed that when exceeded, the wafer transfer device is stopped.

  Further, as a technique related to the detection of the drooping of the wafer, for example, there are techniques as in Patent Documents 3 and 4 below.

  In Patent Document 3, the detection means (sensor) for detecting the workpiece in the workpiece carrier is moved in the vertical direction of the end of the workpiece to detect the position of the workpiece when the position is detected. When the end of the workpiece is no longer detected, the position is stored in the second storage device, and the workpiece can be detected from the position stored in the first and second storage devices. Computing the width is disclosed.

  In Patent Document 4, a measurement unit that is installed separately from the carrier and directly measures the distance to the predetermined portion of the wafer or the thickness of the wafer, and the inclination of the carrier is changed. And a tilt mechanism that corrects the tilt.

JP 2003-17548 A JP-A-7-147314 Japanese Patent Laid-Open No. 7-58187 JP 2002-305224 A

  By the way, in the case of Patent Document 1, since the light projecting head and the light receiving head are arranged vertically opposite to each other on the opening surface side of the cassette, it is possible to detect the presence / absence of a wafer jumping out of the cassette through the entire cassette. It is impossible to detect from which slot of the cassette the wafer is protruding. In the configuration of Patent Document 1, it is not possible to detect the drooping of the wafer in the cassette.

  In the case of Patent Document 2, since it has a configuration in which the wafer transfer device is moved in the vertical direction and the distance to the wafer is measured by the distance measurement sensor in order from the first wafer, unlike Patent Document 1, It is possible to detect from which slot of the cassette the wafer is protruding. However, just for the purpose of detecting the jumping out of the wafer, it is necessary to move the wafer transfer device equipped with the distance measurement sensor up and down sequentially (mechanical scan) for each wafer in the cassette. Therefore, there is a problem that the detection time becomes longer by the time taken for.

  In the case of Patent Document 3, a configuration similar to that of Patent Document 2 in which the detection means is moved in the vertical direction is provided, and the tilt of the wafer can be detected for each wafer in the cassette. Similarly to the above, it is necessary to move the detection means in the vertical direction only for the purpose of detecting the tilt of the wafer. For this reason, there exists the same subject as patent documents 2.

  In the case of Patent Document 4, it is assumed that the wafer is transferred in the transfer direction from the carrier transfer port at a predetermined transfer height, and the distance from the measurement unit to the predetermined portion of the wafer (transfer distance) A configuration for detecting the tilt of the wafer based on the measurement result is provided. Therefore, for the purpose of detecting the inclination of all the wafers in the carrier, it is necessary to move the carrier in the vertical direction so that each wafer is positioned at the transfer port. For this reason, there exists the same subject as patent documents 2.

  The present invention has been made to solve the above-described problems, and its purpose is to provide at least the amount of protrusion of the substrate as an index that quantitatively represents the storage state of the substrate stored in each slot of the substrate storage container. And it is in detecting the amount of sagging of a board | substrate rapidly with a simple structure.

In order to solve the above problems, a substrate storage state detection device according to the present invention stores a plurality of flat-plate-shaped substrates in predetermined storage positions, and arranges the plurality of substrates as a whole in the thickness direction of the substrate. A substrate storage state detection device for detecting a storage state of the substrate stored in a substrate storage container having a plurality of slots to be stored and an opening for carrying out the substrate, the substrate storage state detecting device Based on the image picked up by the image pick-up means, the image pick-up means for picking up the image of the end of the substrate on the side of the opening housed in each slot viewed from the direction intersecting the carry-out direction, As an index that quantitatively represents the storage state of the substrate being stored, the amount of protrusion of the substrate protruding from the predetermined storage position to the front of the opening and the end on the opening side hang down. And detects a drooping amount of the substrate are a substrate housing detecting means which outputs a pop-out amount and sag amount of the detected substrate, adjacent to the opening, and opposing along the crossing direction the A collimator plate provided on one side surface of the two side surfaces of the substrate storage container; and a collimator plate provided on the other side surface of the two side surfaces of the substrate storage container and emitting light in a plane toward the collimator plate. Radiating means, and the collimator plate and the illuminating means are arranged on the opening side of the substrate housed in each slot in a planar light path from the illumination means to the collimator plate. The imaging unit is disposed so that the end portion is located, and the imaging unit is housed in each slot formed on the collimator plate by light emitted in a planar shape from the illumination unit. Capturing an image of the end of the opening side.

According to said structure, the image of the edge part by the side of the opening part of the board | substrate accommodated in each slot of a board | substrate storage container is imaged using an imaging means, and each board | substrate storage container is based on this imaged image. As an index that quantitatively represents the storage state of the substrate stored in the slot, it is possible to detect at least the amount of protrusion of the substrate and the amount of sagging of the substrate at a time, and includes at least a substrate storage state detection device and a robot It is possible to simplify the configuration of the entire substrate carry-out system and to shorten the substrate storage state detection processing time, and consequently the overall substrate carry-out processing time. Further, according to the above configuration, it is possible to acquire an image of the end portion on the opening side of the substrate housed in each slot without performing a mechanical scan, and the substrate unloading system configuration can be simplified and The substrate carry-out processing time can be shortened.

  In the substrate storage state detection device described above, it is determined whether or not the amount of protrusion detected by the substrate storage state detection means is included in a first holdable range that can be held when the substrate is carried out, or The apparatus may further include a substrate holding availability determining unit that determines whether or not the sagging amount detected by the substrate storage state detecting unit is included in a second holdable range that can be held when the substrate is unloaded. Good.

  According to the above configuration, it is possible to automatically determine and evaluate the detected amount of jumping out of the substrate and amount of sagging of the substrate from the viewpoint of the possibility of holding during the substrate carry-out processing. Accordingly, for example, if the detected amount of protrusion or sag of the substrate is small (that is, if it is included in the first or second holdable range), the substrate carry-out process (each slot by the holding tool of the robot) The holding and transporting of the substrates housed in the substrate can be continued without stopping, and the overall throughput of the substrate unloading system can be improved.

  In the above-described substrate storage state detection device, a robot including a robot arm and a holding tool that holds the substrate provided at a tip portion of the robot arm is controlled to change the substrate holding position of the holding tool and Robot control means for carrying out the substrate stored in each slot of the substrate storage container from the slot through the opening, the robot control means is further based on the determination result of the substrate holding availability determination means The robot may be controlled.

  According to the above configuration, depending on the amount of jumping out and dripping of the substrate, it may be possible to hold the robot with the holding tool of the robot. In this case, the substrate carry-out processing can be continued without stopping. Thus, the throughput of the entire substrate carry-out system can be improved.

  In the substrate storage state detection device, the robot control unit may determine that the amount of protrusion is out of the first holdable range or the amount of sag is out of the second holdable range by the substrate holding availability determination unit. When it is determined that the robot is present, the robot may be controlled to skip carrying out the determined substrate.

  According to the above configuration, when the detected amount of jumping out or drooping of the substrate is large, it is determined that the detected amount of popping out and drooping of the substrate can be held as a result of skipping board carry-out. Since the holding and unloading are performed only for the substrate that has been performed, the substrate unloading process can be performed reliably and promptly.

  In the substrate storage state detection apparatus, the robot control unit may determine that the amount of protrusion is within the first holdable range or the amount of sag is within the second holdable range by the substrate holding availability determination unit. When it is determined that there is, the substrate holding position of the holding tool may be corrected in accordance with the pop-out amount or the sagging amount.

  According to the above configuration, when the detected amount of protrusion or drooping of the substrate is small, it is possible to correct the substrate holding position of the holding tool without skipping the substrate carry-out.

  In the substrate storage state detection apparatus, the robot control unit moves the holding tool to the substrate holding position so as to be within the field of view of the imaging unit, and the opening of the substrate imaged by the imaging unit The substrate holding position of the holding tool may be further corrected based on the side end portion and the image of the holding tool.

  According to the above configuration, it is possible to more accurately determine the possibility of holding a substrate using not only information on the substrate storage container side but also information on the robot side.

In addition, the substrate storage state detection method of the present invention for solving the above-described problem is to store a plurality of flat plate-shaped substrates in predetermined storage positions, respectively, and arrange the plurality of substrates in the thickness direction of the substrate as a whole. A substrate storage state detection method for detecting a storage state of the substrate stored in a substrate storage container comprising a plurality of slots to be stored and an opening for carrying out the substrate , adjacent to the opening, And a step in which a collimator plate is provided on one side surface of the two side surfaces of the substrate storage container facing each other along the intersecting direction, and the collimator on the other side surface of the two side surfaces of the substrate storage container. Bei; providing an illumination means for emitting light in a planar shape toward the plate, and a holding tool for holding the substrate disposed on the distal end portion of the robot arm and the robot arm Controlling the robot to change the substrate holding position of the holding tool and unloading the substrate stored in each slot of the substrate storage container from the slot through the opening; And taking an image of an end of the substrate on the opening side stored in each slot as viewed from a direction intersecting the carrying-out direction of the substrate, and in each slot based on the taken image As an index that quantitatively represents the storage state of the stored substrate, the amount of the substrate protruding from the predetermined storage position to the front of the opening and the substrate on which the end on the opening side hangs down and detects the sag amount of includes a step of outputting the pop-out amount and sag amount of the detected substrate, wherein the collimator plate and the illumination unit, the irradiation The end of the substrate on the opening side of the substrate housed in each slot is positioned in the optical path of the planar light from the means toward the collimator plate, and on the opening side of the substrate In the step of taking an image of the edge portion, an image of the edge portion on the opening side of the substrate housed in each slot formed on the collimator plate by light emitted in a planar shape from the illumination means is obtained. The image is taken.

  According to the present invention, at least the amount of protrusion of the substrate and the amount of sagging of the substrate can be quickly detected with a simple configuration as an index that quantitatively represents the storage state of the substrate stored in each slot of the substrate storage container. .

FIG. 1A is a diagram showing a configuration of a wafer carry-out system including a substrate storage state detection apparatus according to the first embodiment of the present invention. FIG. 1B is a diagram illustrating a hardware configuration of the system control apparatus illustrated in FIG. 1A. FIG. 1C is a diagram for explaining the arrangement of the collimator plate and the illumination means (retroreflective plate) included in the substrate storage state detection apparatus according to the first embodiment of the present invention. FIG. 2 is a perspective view of an example of a cassette according to the present invention. FIG. 3 is a flowchart showing an overall flow of wafer carry-out processing by the substrate storage state detection apparatus according to the first embodiment of the present invention. FIG. 4 is a flowchart showing the flow of the master image registration process according to the present invention. FIG. 5 is a diagram showing an example of a master image according to the present invention. FIG. 6 is a diagram illustrating an example of a sampling image when the storage state of the substrate according to the present invention is not normal. FIG. 7 is a flowchart showing the flow of the wafer storage state detection process performed by the substrate storage state detection device according to the first embodiment of the present invention. FIG. 8 is a diagram for explaining a pop-out slot error according to the present invention. FIG. 9 is a view for explaining a drooping wafer slot error according to the present invention. FIG. 10 shows a modified example of the wafer carry-out system 1A in the first embodiment of the present invention shown in FIGS. 1A and 1C. FIG. 11 shows another modification of the wafer carry-out system 1A in the first embodiment of the present invention shown in FIGS. 1A and 1C. FIG. 12 shows still another modification of the wafer carry-out system 1A according to the first embodiment of the present invention shown in FIGS. 1A and 1C. FIG. 13 is a flowchart showing the flow of wafer carry-out processing by the substrate storage state detection apparatus according to the third embodiment of the present invention. FIG. 14 is a diagram for explaining the FOUP system.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and redundant description thereof is omitted.
(First embodiment)
[Configuration of substrate storage state detection device]
Hereinafter, as an example of a system using the substrate storage state detection apparatus according to the first embodiment of the present invention, a wafer carry-out system in a mini-environment housing will be described as an example.

  FIG. 1A is a diagram showing a configuration of a wafer carry-out system 1A including a substrate storage state detection apparatus according to the first embodiment of the present invention. FIG. 1B is a diagram illustrating a hardware configuration of the system control device 60 illustrated in FIG. 1A. FIG. 1C is a diagram for explaining the arrangement of the collimator plate 4 and the retroreflective plate 5 which is an example of the illumination unit included in the substrate storage state detection device according to the first exemplary embodiment of the present invention.

  The substrate storage state detection device included in the wafer unloading system 1A is stored in all slots 18 in the cassette 10 before unloading a plurality of wafers (substrates) 11 stored in the cassette 10 (substrate storage container). As an index that quantitatively represents the stored state of the wafer 11, at least the amount of protrusion and sag of the wafer 11 from the slot 18 is detected and output. Further, the substrate storage state detection device described above determines the possibility of holding the wafer of the hand (holding tool) 36 attached to the tip of the robot arm 32 of the robot 30 based on the detection results of the jumping amount and sagging amount of the wafer 11. In addition, if it is determined that the wafer can be held and if necessary, the wafer holding position (substrate holding position) is corrected. Further, the substrate storage state detection device directs the wafer 11 determined to be held by the hand 36 to the predetermined substrate processing position of the semiconductor manufacturing apparatus (not shown) with respect to the detection result of the protrusion amount and the sagging amount of the wafer 11. To be carried out.

  The wafer 11 is a thin flat-plate semiconductor substrate, and is housed in a rectangular parallelepiped cassette 10 such as OC (Open Cassette) or FOUP (Front-Opening Unified Pod) shown in FIG. The cassette 10 is hermetically sealed by a door (not shown) and the opening 19 in which the wafer 11 is carried in and out with the door open, and a plurality of wafers 11 are arranged in the thickness direction of the wafer 11, And a plurality of slots 18 to be stored in a horizontal state. The wafers 11 stored in the slots 18 of the cassette 10 are identified based on the slot numbers assigned to the slots 18.

  The wafer carry-out system 1 </ b> A includes a point light source 2, an imager 3, a collimator plate 4, a retroreflective plate 5, a robot 30, and a system control device 60. In addition, the board | substrate accommodation state detection apparatus which concerns on the 1st Embodiment of this invention is comprised by the point light source 2, the image pick-up device 3, the collimator board 4, the retroreflection board 5, and the system control apparatus 60. Yes.

  The point light source 2, the collimator plate 4, and the retroreflective plate 5 are openings of the wafers 11 accommodated in all the slots 18 in the cassette 10 from the direction intersecting the arrangement direction of the wafers 11 and the unloading direction of the wafers 11. Illumination means for irradiating light toward the end on the 19th side is configured. The collimator plate 4 further constitutes an image forming unit that forms an image of the end of the wafer 11 on the opening 19 side. The illumination means, the image forming means, and the image pickup device 3 constitute an image pickup means. Here, the reason why light is projected from the direction intersecting with the arrangement direction of the wafers 11 and the unloading direction of the wafers 11 (and thus imaging) is that the wafers 11 overlap each other when imaged from the arrangement direction of the wafers 11. This is because if the image is taken from the carry-out direction of the wafer 11, the extent of the protrusion of the wafer 11 cannot be imaged. Therefore, in order to suitably detect the storage state of the wafer 11, it is preferable to image from the direction orthogonal to the arrangement direction of the wafers 11 and the unloading direction of the wafers 11.

  The collimator plate 4 is adjacent to the opening of the cassette 10 and faces one of the two side surfaces of the cassette 10 facing the direction in which the wafer 11 is arranged and intersecting the unloading direction (point light source 2 and imaging). On the side facing the container 3). Further, the mirror normal of the collimator plate 4 and the camera optical axis of the image pickup device 3 are determined to be parallel on the plan view (see FIG. 1C). In the present embodiment, the collimator plate 4 is constituted by a radiation mirror. The collimator plate 4 may be constituted by a curved mirror formed by combining a plurality of small planar mirrors as a whole into a substantially curved surface (concave surface) instead of the parabolic mirror.

  The point light source 2 is disposed on the other side surface of the two side surfaces of the cassette 10. Moreover, the point light source 2 is arrange | positioned in the position of the substantially half height of the cassette 10 so that the edge part of the several wafer 11 accommodated in the cassette 10 may be irradiated (refer FIG. 1C). In the present embodiment, the point light source 2 is composed of a high-intensity light source composed of a light emitting diode.

  The image pickup device 3 is disposed substantially coaxially with the point light source 2 on the other side surface side of the cassette 10. In the present embodiment, the image pickup device 3 is configured by a CCD (Charge Coupled Device) camera. The image pickup device 3 may be configured by a CMOS (Complementary Metal Oxide Semiconductor) camera or the like in addition to the CCD camera.

  The retroreflective plate 5 is arranged on the other side surface side of the cassette 10 so that the end portions of the plurality of wafers 11 are positioned on the optical path of the collimated light between the collimator plate 4 and the retroreflective plate 5 ( (On the side facing the collimator plate 4). In this embodiment, the retroreflecting plate 5 is constituted by a μCCR (μ Corner Cube Reflector) plate.

  When the wafer carry-out system 1A configured as described above detects the storage state of the wafer 11 in the cassette 10, the following procedure is performed.

  First, diffused light is emitted from the point light source 2 toward the collimator plate 4, reflected by the collimator plate 4, and collimated. Next, the collimated light reflected by the collimator plate 4 travels toward the retroreflective plate 5 disposed facing the collimator plate 4. Next, the collimated light reflected by the retroreflecting plate 5 travels (retroreflects) toward the collimator plate 4. As a result, transmission images of the end portions of the plurality of wafers 11 on the opening 19 side are shown on the collimator plate 4. Then, the image pickup device 3 captures images of the end portions on the opening 19 side of the plurality of wafers 11 shown on the collimator plate 4. In other words, the transmitted images of the end portions on the opening 19 side of the plurality of wafers 11 are reflected by the collimator plate 4 and formed on the light receiving surface of the image pickup device 3. Thus, the image pickup device 3 picks up images of the end portions of the plurality of wafers 11 on the opening 19 side. Since the mirror normal of the collimator plate 4 and the camera optical axis of the image pickup device 3 are parallel on the plan view, the image of the wafer 11 is formed as a parallel image on the transmission image.

  The robot 30 is an industrial robot such as a horizontal articulated type or a vertical articulated type that carries out the wafers 11 stored in the cassette 10 one by one and transports them to a predetermined substrate processing unit of the semiconductor manufacturing apparatus 105. . The robot 30 has a hand 36 (holding tool) that holds the wafer 11 (including gripping and clamping) attached to the tip portion of the robot arm 32, and each rotation of the plurality of robot arms 32 constituting the robot arm 32 is performed. The rotation about the axis can be performed independently of each other. That is, the robot 30 stops the hand 36 at a desired position in a desired posture by controlling the rotation position of each rotation axis of the plurality of robot arms 32, and controls the hand by controlling the angular velocity of each rotation axis of the plurality of robot arms 32. 36 can be moved at a desired speed along a desired path.

  The system control device 60 includes a substrate storage state detection unit 61, a substrate holding availability determination unit 64, a robot control unit 65, and a storage unit 66. The substrate storage state detection means 61 captures images (end images to be described later, master images and sampling images) of the end portions on the side of the openings 19 of the plurality of wafers 11 imaged by the image pickup device 3 and performs image processing to be described later. 62, and a substrate storage state determination unit 63 that determines the storage state of the wafer 11 based on the image processed by the image processing unit 62. When the substrate storage state detection unit 61 detects the protrusion of the wafer 11 (first substrate storage state), the substrate holding possibility determination unit 64 determines the amount of protrusion of the wafer 11 based on the image captured by the imager 3. Is included in the pop-out holdable range (first holdable range) in which the wafer 11 can be held by the hand 36, and the substrate storage state detection means 61 determines whether the wafer 11 hangs (second substrate storage). When the state is detected, based on the image picked up by the image pickup device 3, the amount of sag of the wafer 11 falls within a sagable holdable range (second holdable range) in which the wafer 11 can be held by the hand 36. It is determined whether or not it is included. The robot control means 65 controls the operation of the robot 30 and changes the wafer holding position of the hand 36 to carry out the wafers 11 stored in the slots 18 of the cassette 10. The storage unit 66 stores predetermined data and the like.

  FIG. 1B shows a hardware configuration of a system control device 60 that realizes the substrate storage state detection unit 61, the substrate holding availability determination unit 64, and the robot control unit 65. According to FIG. 1B, the system control device 60 has a CPU (Central Processing Unit) 650 that controls the entire device, and an I / O (Input / Output) that exchanges information between the robot 30 and the image pickup device 3. A port (651), a ROM (Read Only Memory) 652 that stores a control program for the robot 30, and a RAM (Random Access) that stores control parameters used in the control program, master data relating to a master image described later, sampling data relating to a sampling image, and the like. Memory) 64. The means 61, 64, 65, 66 are functions realized by the CPU 650 reading and executing a control program stored in the ROM 652.

The system control device 60 may have a centralized configuration with a single CPU 650 or a distributed configuration with a plurality of CPUs 650. Therefore, a later-described wafer carry-out process (see FIG. 3) and a later-described wafer storage state detection process (see FIG. 7) may be executed by separate CPUs 650. Further, the image processing unit 65 may be configured by a dedicated LSI, not by software.
[Whole unloading process flow]
FIG. 3 is a flowchart showing an overall flow of wafer unloading processing by the wafer unloading system 1A. The system control device 60 executes a wafer storage state detection process (see FIG. 7), which will be described later, after the cassette 10 storing the wafer 11 arrives at the predetermined stop position shown in FIGS. 1A and 1C (step S301). (Step S302). Then, the system control device 60 performs a desired process based on an execution result of a wafer storage state detection process (see FIG. 7) described later. For example, all the wafers 11 for which the storage state has not been detected are unloaded by the hand 36 of the robot 30 (steps S303 and S304).
[Master image registration process flow]
FIG. 4 is a flowchart showing the flow of the master image registration process according to the present invention.

  First, it is assumed that the wafers 11 are normally stored in all the slots 18 in the cassette 10. Note that normal storage means that there is no substrate storage state called “Jump slot”, “Cross slot”, “No wafer slot”, “Double slot”, or “Slot wafer slot” described later. Refers to that. Here, whether a certain substrate storage state is called normal or abnormal is simply a matter of selection of the calling method. The system control device 60 takes images of the end portions of the plurality of wafers 11 normally stored in the cassette 10 by the image pickup means 3, and uses the images (transmission images) of the end portions of the plurality of wafers 11 as master images. Obtain (step S401). Note that the master image is an image used as a reference (reference) in a wafer storage state detection process described later.

  An example of the master image is shown in FIG. The master image 20 shown in FIG. 5 is an image in which the portions shielded by the respective end portions of the plurality of wafers 11 appear as a plurality of local light shielding portions (low luminance portions). The X-axis direction of the master image 20 shown in FIG. 5 is associated with the arrangement direction shown in FIG. 1C, and the Y-axis direction of the master image 20 shown in FIG. Are associated with the unloading direction shown in FIG.

  Next, the system control device 60 sequentially performs binarization processing, labeling processing, and feature amount extraction processing on the master image acquired from the image pickup device 3 by the image processing unit 62. Here, the binarization processing refers to two luminance values of white (high luminance) and black (low luminance) based on a certain threshold value for the luminance (average value of RGB values) of each pixel constituting the master image. It refers to the process of dividing into. The labeling process refers to a process of assigning and classifying a collection of pixels having the same luminance value in each pixel constituting the master image.

  The feature amount extraction processing refers to processing for extracting feature amounts such as the center of gravity position, posture, area, tip position, and inclination based on the master image on which the labeling processing has been performed. Note that the center-of-gravity position refers to a position where a label attached to a pixel aggregate by a labeling process can be supported at one point. The posture is the posture of a collection of pixels assigned the same label, the area is the area of the collection of pixels, and the tip position is the tip position of the collection of pixels, The inclination refers to the inclination of the pixel assembly with respect to a predetermined reference line (X axis or Y axis). Therefore, the protrusion amount of the wafer 11 described later can be detected based on the feature amount such as the tip position, and the sagging amount of the wafer 11 described later is detected based on the feature amount such as the inclination. Can do.

  Then, the system control device 60 stores each processing result of the above-described binarization processing, labeling processing, and feature amount extraction processing relating to the master image by the image processing unit 62 in the storage unit 66 as master data (step S403). Thereby, the registration process of the master image is completed.

In the above, an example of registration processing of a master image used as a reference (reference) in a wafer storage state detection process described later has been described. However, reference (reference) data of the master image or the like is obtained by another method different from the above. You can also. For example, it can be obtained only by calculation from the thickness on the standard of the wafer.
[Sample images when board storage is not normal]
FIG. 6 is a diagram illustrating an example of an image (hereinafter referred to as a sampling image) of end portions on the opening 18 side of a plurality of wafers 11 captured by the image pickup device 3 when the storage state of the wafer 11 is not normal. .

  The “pop-out slot (first substrate storage state)” shown in FIG. 6 refers to an event in which the wafer 11 has jumped forward more than a predetermined amount from a predetermined storage position in a slot 18 of the cassette 10. It should be noted that the “jumping amount” is a distance from the tip position of the wafer 11 stored in the specified storage position of the slot 18 to the tip position of the wafer 11 stored in the slot 18 where the “popping slot” is generated. Refers to distance. When such a pop-out slot occurs, an image portion appears in the sampling image 22 such that the corresponding light shielding portion is longer in the Y-axis direction than the other light shielding portions.

  The “hanging wafer slot (second substrate storage state)” shown in FIG. 6 is an event in which the wafer stored in the slot 18 of the cassette 10 hangs down more than the specified position below the specified position. That means. The “sagging amount” refers to the position from the front end position of the wafer 11 stored in the specified storage position of the slot 18 to the front end position of the wafer 11 stored in the slot 18 where the “sagging wafer slot” occurs. Refers to distance. When such a drooping wafer slot occurs, an image in which a portion corresponding to the sampling image 22 is inclined appears.

  “Cross slot (third substrate storage state)” shown in FIG. 6 refers to an event in which one wafer 11 is stored in a different slot 18 in different levels. When such a cross slot occurs, in the sampling image 22, the corresponding light shielding portion (low luminance portion) is thicker in the X-axis direction than the other light shielding portions, and at the two slot positions. An image portion that straddles will appear.

  The “no-wafer slot (fourth substrate storage state)” shown in FIG. 6 refers to an event in which no wafer 11 is stored in a certain slot 18 in the cassette 10. When such a waferless slot occurs, an image portion in which the light-shielding portion corresponding to the sampling image 22 is missing appears.

  The “double slot (fifth substrate storage state)” shown in FIG. 6 refers to an event in which two wafers 11 are stored in the same slot 18 in an overlapping manner. When such a double slot occurs, an image appears in the sampling image 22 in which the corresponding portion is twice as thick in the X-axis direction as the other light shielding portions.

[Flow of wafer storage status detection process]
FIG. 7 is a flowchart showing the flow of the wafer storage state detection process in the first embodiment of the present invention. The wafer storage state detection process corresponds to the wafer storage state detection process in step S302 shown in FIG.

  First, the board storage state determination unit 63 of the system control device 60 reads out master data relating to the master image stored in the storage unit 66 (step S701).

  Next, the system controller 60 opens the openings 19 of the plurality of wafers 11 accommodated in all the slots 18 in the cassette 10 with respect to the cassette 10 that has arrived at the predetermined stop position shown in FIGS. 1A and 1C. An image of the side end is picked up by the image pickup device 3, and the picked-up image is acquired as a sampling image (step S702).

  Next, the system control device 60 sequentially performs binarization processing, labeling processing, and feature amount extraction processing on the sampled image acquired from the image pickup device 3 by the image processing unit 62 (step S703). Note that these processes are the same as the processes executed on the master image. Then, the system control device 60 stores the processing results of the above-described binarization processing, labeling processing, and feature amount extraction processing regarding the sampling image by the image processing unit 62 in the storage unit 66 as sampling data.

  Next, the system control device 60 (more precisely, the substrate storage state determination unit 63) compares the master data stored in the storage unit 66 with the sampling data, and thereby the wafers in the cassette 10 as in the following steps. 11 is detected whether the storage state is normal (step S704).

  First, the system controller 60 detects the presence / absence of “no wafer slot” among the plurality of wafers 11 in the cassette 10 represented in the sampling image (step S705). Here, the determination result is “OK” when there is no slot without a wafer, and the determination result is “NG” when there is a slot without a wafer. In the case of the determination result “NG”, it is defined as “no wafer slot error” and output to the outside, and stored in the storage means 66 in association with the slot number of the slot 18 corresponding to the no wafer slot (step S706). ). If the determination result is “OK”, the process proceeds to the next step S707.

  Next, the system control device 60 detects the presence / absence of a “cross slot” among the plurality of wafers 11 in the cassette 10 represented in the sampling image (step S707). Here, the determination result is “OK” when there is no cross slot, and the determination result is “NG” when there is a cross slot. In the case of the determination result “NG”, it is defined as “cross slot error” and output to the outside, and stored in the storage means 66 in association with the slot number of the slot 18 corresponding to the cross slot (step S708). If the determination result is “OK”, the process proceeds to the next step S709.

  Next, the system control device 60 detects the presence / absence of a “double slot” in the plurality of wafers 11 in the cassette 10 represented in the sampling image (step S709). Here, the determination result is “OK” when there is no double slot, and the determination result is “NG” when there is a double slot. In the case of the determination result “NG”, it is defined as “double slot error” and outputted to the outside, and stored in the storage means 66 in association with the slot number of the slot 18 corresponding to the double slot (step S710). If the determination result is “OK”, the process proceeds to the next step S711.

  Next, the system control device 60 detects the presence / absence of a “pop-out slot” among the plurality of wafers 11 in the cassette 10 represented in the sampling image (step S711). Here, the determination result is “OK” when there is no pop-out slot, and the determination result is “NG” when there is a pop-out slot. In the case of the determination result “NG”, an error is not immediately output to the outside, but the amount of protrusion of the wafer 11 stored in the protrusion slot is within a range in which the wafer 11 can be held by the hand 36 of the robot 30 (hereinafter, referred to as “NG”). It is determined whether or not it is within the pop-out holdable range (step S712). The pop-out holdable range is, for example, an area hatched by hatching shown in FIG. 8 and indicates a certain range in the image Y-axis direction shown in FIG. 1A. This area can be determined as an area where the hand 36 of the robot 30 can hold the wafer 11 to be held without interfering with the cassette 10 or the wafer 11 other than the holding object, for example.

  If the protruding amount of the wafer 11 is within the pop-out holdable range, the determination result is “OK”. If the pop-out amount of the wafer 11 is outside the pop-out holdable range, the determination result is “NG”. In the case of the determination result “NG”, it is defined as “pop-out slot error” and outputted to the outside, and stored in the storage means 66 in association with the slot number of the slot 18 corresponding to the pop-out slot (step S713). In the case of the determination result “OK”, the system control device 60 adjusts the position of the hand 36 of the robot 30 so as to match the front end position of the wafer 11 that has jumped out without exceeding the pop-out holding range stored in the pop-out slot. The wafer holding position is corrected (step S714), and the process proceeds to the next step S715.

  Next, the system control device 60 detects the presence / absence of a “dripping wafer slot” among the plurality of wafers 11 in the cassette 10 represented in the sampling image (step S715). Here, the determination result is “OK” when there is no sagging wafer slot, and the determination result is “NG” when there is a sagging wafer slot. In the case of the determination result “NG”, an error is not immediately output to the outside, but the drooping amount of the wafer 11 accommodated in the dripping wafer slot is within a range in which the wafer 11 can be held by the hand 36 of the robot 30 (hereinafter, “ It is determined whether or not it is within the droop holdable range (step S716). Note that the droopable holding range is, for example, a hatched area shown in FIG. 9, and indicates a certain range in the image X-axis direction shown in FIG. 1C. This area can be determined as an area where the hand 36 of the robot 30 can hold the wafer 11 to be held without interfering with the cassette 10 or the wafer 11 other than the holding object, for example.

  If the sagging amount of the wafer 11 is within the sagging holdable range, the determination result is “OK”. If the sagging amount of the wafer 11 is outside the sagging holdable range, the judgment result is “NG”. In the case of the determination result “NG”, it is defined as “dripping wafer slot error” and outputted to the outside, and stored in the storage means 66 in association with the slot number of the slot 18 corresponding to the dripping wafer slot (step S717). ). In the case of the determination result “OK”, the system controller 60 adjusts the hand 36 of the robot 30 so as to match the tip position of the wafer 11 that is drooping without exceeding the droop holding range accommodated in the dripping wafer slot. The wafer holding position is corrected (step S718).

Note that the system controller 60 determines that there is no wafer slot error (step S706), cross slot error (step S708), double slot error (step S710), pop-out slot error (step S713), or drooping wafer slot error (step S717). The wafer 11 accommodated in the slot 18 in which the occurrence of this occurs is configured to skip holding and unloading by the hand 36 in the wafer unloading operation (step S303) shown in FIG.
[effect]
According to the substrate storage state detection apparatus according to the present embodiment, an image of the end portion of the wafer 11 stored in the cassette 10 is acquired at one time using one imaging device 3, and the acquired image Based on the above, at least the presence / absence of “pop-out slot” and “dripping wafer slot” can be detected as the accommodation state of the wafer 11 in the cassette 10 at a time, thereby simplifying the system configuration and shortening the time required for unloading processing. Will be illustrated.

  Note that the wafer carry-out system 1A uses the image pickup device 3 to detect an index representing the state of accommodation of the wafer 11, such as the amount of protrusion and the amount of sag of the wafer 11, and depends on the reflectance of the wafer 11 that is the object. Thus, the storage state of the wafer 11 can be reliably detected. Furthermore, since an image having a certain width (the length in the Y-axis direction shown in FIG. 6) can be obtained, it is possible to reliably detect the presence or absence of a pop-up slot.

  Further, since the presence or absence of the pop-out slot is detected based on the change in the length of the light shielding portion in the sampling image in the Y-axis direction (see FIG. 6), the amount of pop-out of the wafer can be easily quantified. Similarly, since the presence / absence of a sagging wafer slot is detected based on the inclination of the light-shielding portion in the image, the sagging amount of the wafer can be easily quantified.

  According to the substrate storage state detection apparatus according to the present embodiment, on the basis of the image picked up by the image pickup device 3, in addition to the presence / absence of the “projection slot” and the “hanging wafer slot”, “no wafer slot”, “ The presence or absence of “cross slot” and “double slot” can also be detected at a time.

  Note that by determining the detection of the double slot based on the area value, the detection value varies greatly between the case of the double slot and the case of the normal. For this reason, the double slot can be detected more reliably than in the conventional technique using a profile.

According to the substrate storage state detection apparatus according to the present embodiment, the robot 30 can be held and transported by the hand 36 of the robot 30 even when the “slip-out slot” and the “hanging wafer slot” are detected. By correcting the control parameters (such as the wafer holding position), the unloading operation of the wafer 11 can be continued without stopping the robot 30. As a result, the throughput of the entire wafer carry-out system 1A can be improved.
[Modification]
The substrate storage state detection device included in the wafer carry-out system 1B shown in FIG. 10 is a modification of the substrate storage state detection device according to the first embodiment of the present invention shown in FIGS. 1A and 1C.

  The substrate storage state detection device included in the wafer carry-out system 1B is a transmissive surface light source at the position of the retroreflector 5 shown in FIGS. 1A and 1C instead of the point light source 2 shown in FIGS. 1A and 1C. The parallel light from the transmissive surface light source 12 is radiated toward the collimator plate 4. The transmissive surface light source 12 includes an LED light source 13 configured by vertically arranging LED elements, and a diffuse transmission plate 14 that transmits light emitted from the LED light source 13. The diffuse transmission plate 14 is made of, for example, frosted glass. The light immediately after being emitted from the LED light source 13 has unevenness, but by transmitting through the diffusion transmission plate 14, a surface light source having uniform brightness without unevenness can be obtained. Therefore, also in the substrate storage state detection apparatus shown in FIG. 10, the images (sampling images) of the edges of the plurality of wafers 11 projected on the collimator plate 4 are picked up by the image pickup device 3, and the image processing unit 62 By analyzing the transmission image, the same effect can be obtained.

  The substrate storage state detection device included in the wafer carry-out system 1C shown in FIG. 11 is another modification of the substrate storage state detection device according to the first embodiment of the present invention shown in FIGS. 1A and 1C.

  The substrate storage state detection device included in the wafer carry-out system 1C uses a reflective surface light source 15 instead of the transmissive surface light source 12 shown in FIG. The reflective surface light source 15 is configured to reflect the light emitted from the LED light source 13 with the diffuse reflector 16. Even with such a reflective surface light source 15, uniform light without unevenness can be emitted toward the collimator plate 4. Therefore, the same effect can be obtained in the substrate storage state detection apparatus shown in FIG.

  The substrate storage state detection device included in the wafer carry-out system 1D shown in FIG. 12 is still another modification of the substrate storage state detection device according to the first embodiment of the present invention shown in FIGS. 1A and 1C. .

  The substrate storage state detection device included in the wafer carry-out system 1D has a diffuse reflector 7 disposed at the position of the retroreflector 5 shown in FIGS. 1A and 1C. A point light source 2 is provided, and at least the image pickup device 3 and the point light source 2 are configured for a plurality of cassettes 10. Thereby, the wafer unloading system 1D can be made compact and the cost can be reduced. In this modification, the light from the point light source 2 provided in the robot 30 is reflected toward the end of the wafer 11 by the diffuse reflector 7 and further reflected toward the image pickup device 3 by the collimator plate 4. The As described above, if the image pickup device 3 is provided in the robot 30, an image representing the storage state of the wafer 11 can be picked up, and an image of an arbitrary cassette 10 can be picked up from an arbitrary angle by operating the robot 30. Can also be recorded. In the latter case, it is possible to select an optimal imaging angle and position for investigating the cause of the abnormality and examining recurrence prevention measures.

  Further, if the sampling image of the edge of the wafer 11 obtained by the image pickup device 3 is stored in the storage unit 66, when the robot 30 has an abnormality such as a transfer failure or a collision, the sampling at the time of occurrence of the abnormality is performed. The image can be confirmed, and the cause of the abnormality and the recurrence prevention measures can be examined using the sampled image as a clue. Specifically, the sampling image obtained by the image pickup device 3 is stored in the storage unit 66 so that a past sampling image can be referred to as necessary. Only the latest sampling image within the range allowed by the storage capacity of the storage unit 66 may be left, and the old sampling image may be deleted (including when overwritten). In addition, if the configuration is such that deletion of an old sampling image (including a case where it is overwritten) is stopped after detecting an abnormality, it is possible to avoid deleting a sampling image for a certain period of time before the occurrence of the abnormality.

In addition to the wafer 11, the wafer carry-out systems 1 </ b> A to 1 </ b> D described above store other substrates such as a glass substrate for a liquid crystal display device, a glass substrate for a photomask, and an optical disc substrate that are accommodated in a cassette and conveyed. This can also be applied to the detection of.
(Second Embodiment)
In the second embodiment of the present invention, not only the end portion of the wafer 11 but also the image of the tip of the hand 36 is simultaneously captured by the image pickup device 3, and the “pop-out slot” and the “hanging wafer” are based on the captured image. "Slot" is detected. Note that the configuration (including the above-described modification) of the substrate storage state detection apparatus according to the second embodiment of the present invention and the flow of the wafer carry-out processing are the same as those of the first embodiment of the present invention.

  Hereinafter, the second embodiment of the present invention will be described with reference to the flowchart showing the wafer storage state detection process shown in FIG. 7 used in the description of the first embodiment of the present invention.

  First, when capturing a sampling image in step S <b> 702, the system control device 60 adjusts the tip position of the hand 36 within the visual field range of the imager 3 together with the transmission image of the wafer 11 formed on the collimator plate 4. The hand 36 is moved to a position near the wafer holding position. Then, a transmission image of the end portions of the plurality of wafers 11 housed in the cassette 10 and an image of the tip portion of the hand 36 are captured, and the system control device 60 samples the captured images via the interface 62. Get as. For the acquired sampled image, in step S703, binarization processing, labeling processing, and feature amount extraction processing are sequentially executed.

Thereby, the system control device 60 can grasp the relative relationship between the tip position of the wafer 11 to be carried out accommodated in the cassette 10 and the tip position of the hand 36 of the robot 30. In step S711, the presence / absence of a pop-out slot can be detected based on the relative difference between the tip position of the wafer 11 to be carried out and the tip position of the hand 36, which are grasped from the sampling image. Similarly, in step S715, the presence / absence of a sagging wafer slot can be detected based on the relative difference between the tip position of the wafer 11 to be carried out and the tip position of the hand 36, which are grasped from the sampling image.
(Third embodiment)
The third embodiment of the present invention differs from the first embodiment of the present invention only in the flow of wafer carry-out processing. Note that the configuration (including the above-described modification) of the substrate storage state detection device and the flow of the wafer storage state detection process according to the second embodiment of the present invention are the same as those in the first embodiment of the present invention. .

  FIG. 13 is a flowchart showing an overall flow of wafer carry-out processing by the substrate storage state detection apparatus according to the third embodiment of the present invention.

  The system control device 60 performs the wafer storage state detection process shown in FIG. 7 after the cassette 10 storing the plurality of wafers 11 has arrived at the predetermined stop position shown in FIGS. 1A and 1C (step S1301). It executes (step S1302). As a result, the holding and unloading of the wafer 11 stored in the slot 18 in which the no-wafer slot error, cross slot error, double slot error, pop-out slot error, or drooping wafer slot error has occurred are skipped. If the pop-out amount of the wafer 11 is within the pop-out holdable range, the system controller 60 corrects the wafer holding position of the hand 36 as a control parameter of the robot 30 so as to match the position of the pop-out wafer 11. Is done. If the sagging amount of the wafer 11 is within the sagging holdable range, the system controller 60 corrects the wafer holding position of the hand 36 as a control parameter of the robot 30 so as to match the position of the sagging wafer 11. Is done.

  Next, the system control device 60 operates the robot arm 32 and the hand 36 so that the tip position of the hand 36 is within the field of view of the imager 3 together with the transmission image of the wafer 11 formed by the collimator plate 4. (Step S1303). Then, a transmission image of the end portions of the plurality of wafers 11 accommodated in the cassette 10 and an image of the tip portion of the hand 36 are picked up by the image pickup device 3, and the system control device 60 acquires the picked up images. Note that the acquired image is subjected to binarization processing, labeling processing, and feature amount extraction processing in this order in the same manner as the master image and the sampling image. As a result, the system control device 60 can grasp the relative positional relationship between the tip position of the unloadable wafer 11 stored in the cassette 10 and the hand 36 of the robot 30 (step S1304). ).

  Next, the system control device 60 detects whether or not the hand 36 is displaced with respect to the leading end position of the unloadable wafer 11 in the cassette 10 (step 1305). When there is a position shift of the hand 36 (step S1305: NO), the system control device 60 performs correction so that the wafer holding position of the hand 36 matches the position of the unloadable wafer 11 in the cassette 10 ( Step S1306). If there is no position shift of the hand 36 (step S1305: YES), the process proceeds to the next step S1307.

  Then, the system control device 60 carries out all the wafers 11 that can be carried out in the cassette 10 by the robot 30 (steps S1307 and S1308).

As described above, not only the end portion of the wafer 11 stored in the cassette 10 but also the hand 36 of the robot 30 is imaged by the image pickup device 3, and the end portion of the wafer 11 and the tip end of the hand 36 identified from the captured image. The wafer 11 can be unloaded more reliably by correcting the wafer holding position of the hand 36 based on the relative positional relationship with the position.
(Fourth embodiment)
The fourth embodiment of the present invention uses an image obtained by imaging the storage state of the wafer 11 and the state on the robot 30 side in the third embodiment of the present invention, so that the displacement or deformation on the robot 30 side, etc. Is detected. The configuration (including the above-described modification) of the substrate storage state detection device according to the fourth embodiment of the present invention, the flow of the wafer carry-out process, and the flow of the wafer storage state detection process are the first of the present invention. This is the same as the embodiment.

  In the present embodiment, the system control device 60 acquires image information (hereinafter referred to as reference image information) when the normal robot 30 takes a specific posture by the image pickup device 3, and uses the reference image information. Stored in the storage means 66 in advance. Thereafter, the system control device 60 obtains image information (hereinafter referred to as comparative image information) when the robot 30 has the same posture as the specific posture described above, and stores the comparison image information in the storage unit 66. To store. Then, the system control device 60 compares the reference image information stored in the storage unit 66 with the comparison image information, and if there is a difference between the two, it is determined that the robot 30 is displaced or deformed.

  For example, when the reference image information and the comparison image information are shifted in the vertical direction, it can be estimated that there is a high possibility that the hand 36 is bent or the bolt is loose. Alternatively, when the hand is displaced in the longitudinal direction, it can be estimated that there is a high possibility that the driving mechanism of the robot 30 is loose. Further, the system control device 60 may correct the control parameters of the robot 30 based on the comparison result between the reference image information and the comparison image information. Accordingly, even when the robot 30 is displaced or deformed, the unloading operation of the wafer 11 can be continued by correcting the control parameter, and the system stop time can be shortened.

  In the above-described embodiment, the end portion of the wafer 11 accommodated in the cassette 10 is imaged using parallel transmitted light. However, the present invention is not limited to this. For example, according to a general imaging method, the entire periphery of the cassette 10 is brightened, and the light scattered at the end of the wafer 11 accommodated in the cassette 10 is collected to image the end of the wafer 11. It may be configured.

  From the foregoing description, many modifications and other embodiments of the present invention are apparent to persons skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.

  The present invention has an excellent effect of being able to quickly detect the storage state of the substrates stored in all the slots of the substrate storage container that has been transported with a simple configuration before the substrates are held and carried out. In particular, the present invention is useful for a system that detects the storage state of a wafer in the FOUP before unloading the wafer stored in the FOUP.

10 cassette 11 wafer 12 surface light source 13 LED light source 14 diffuse transmission plate 15 surface light source 16 diffuse reflection plate 18 slot 19 opening 1A, 1B, 1C, 1D wafer carry-out system 2 point light source 20 master image 22 sampling image 3 imaging means 30 robot 32 Robot arm 36 Hand 5 Retroreflective plate 60 System controller 61 Substrate storage state detection unit 62 Image processing unit 63 Substrate storage state determination unit 64 Substrate holding availability determination unit 65 Robot control unit 650 CPU
651 I / O port 652 ROM
653 RAM
66 Storage means 7 Diffuse reflector 100 Wafer 101, 106 FFU
102 FOUP
DESCRIPTION OF SYMBOLS 103 FOUP conveyance apparatus 104 Mini-environment housing | casing 105 Semiconductor manufacturing apparatus 107,108 Door part 109 Robot 110 Robot control apparatus

Claims (7)

A substrate provided with a plurality of slots each for storing a plurality of flat-plate-shaped substrates in predetermined storage positions and storing the plurality of substrates arranged in the thickness direction of the substrate as a whole and an opening for carrying out the substrate A substrate storage state detection device for detecting a storage state of the substrate stored in a storage container,
An imaging means for capturing an image of an end portion of the substrate on the side of the opening housed in each slot viewed from a direction intersecting the array direction of the substrate and the unloading direction of the substrate;
Based on the image picked up by the image pickup means, as an index that quantitatively represents the storage state of the substrate stored in each slot, the substrate protruding from the predetermined storage position to the front of the opening A substrate storage state detection means for detecting the amount of protrusion and the amount of substrate dripping at the end on the opening side, and outputting the amount of protrusion and amount of drooping of the detected substrate;
A collimator plate provided on one side of the two side surfaces of the substrate storage container that is adjacent to the opening and is opposed along the intersecting direction;
Illuminating means provided on the other side surface of the two side surfaces of the substrate storage container, and emitting light in a plane shape toward the collimator plate,
The collimator plate and the illuminating means are arranged such that an end portion on the opening side of the substrate housed in each slot is positioned in an optical path of planar light from the illuminating means toward the collimator plate. And
The image pickup means picks up an image of an end portion on the opening side of the substrate housed in each slot formed on the collimator plate by light radiated in a planar shape from the illumination means. State detection device.   It is determined whether the pop-out amount detected by the substrate storage state detection unit is included in a first holdable range that can be held when the substrate is carried out, or is detected by the substrate storage state detection unit. The substrate storage state detection device according to claim 1, further comprising a substrate holdability determination unit that determines whether or not a drooping amount is included in a second holdable range that can be held when the substrate is unloaded. . By controlling a robot including a robot arm and a holding tool that holds the substrate provided at a tip portion of the robot arm, the substrate holding position of the holding tool is changed and stored in each slot of the substrate storage container. Robot control means for unloading the substrate from the slot through the opening,
The substrate storage state detection apparatus according to claim 2 , wherein the robot control unit further controls the robot based on a determination result of the substrate holding possibility determination unit. The robot control means makes the determination when the substrate holdability determination means determines that the pop-out amount is out of the first holdable range or the sagging amount is out of the second holdable range. Controlling the robot to skip unloading of the substrate,
The board | substrate accommodation state detection apparatus of Claim 3 . The robot control means determines the pop-out amount when the substrate holdability determination means determines that the pop-out amount is within the first holdable range or the sagging amount is within the second holdable range. Or the board | substrate accommodation state detection apparatus of Claim 4 which correct | amends the board | substrate holding position of the said holding tool according to the said sagging amount. The robot control means moves the holding tool to the substrate holding position so as to be within the visual field range of the imaging means, and the end portion on the opening side of the substrate imaged by the imaging means and the holding tool The substrate storage state detection device according to claim 5 , wherein the substrate holding position of the holding tool is further corrected based on an image. A substrate provided with a plurality of slots each for storing a plurality of flat-plate-shaped substrates in predetermined storage positions and storing the plurality of substrates arranged in the thickness direction of the substrate as a whole and an opening for carrying out the substrate A substrate storage state detection method for detecting a storage state of the substrate stored in a storage container,
A step for providing a collimator plate on one of the two side surfaces of the substrate storage container adjacent to the opening and facing along the intersecting direction;
Providing an illuminating means for emitting light in a planar shape toward the collimator plate on the other side surface of the two side surfaces of the substrate storage container;
By controlling a robot including a robot arm and a holding tool that holds the substrate provided at a tip portion of the robot arm, the substrate holding position of the holding tool is changed and stored in each slot of the substrate storage container. Unloading the substrate from the slot through the opening;
Capturing an image of an end portion on the opening side of the substrate housed in each slot viewed from a direction intersecting the array direction of the substrate and the unloading direction of the substrate;
Based on the captured image, as an index that quantitatively represents the storage state of the substrate stored in each slot, the amount of the substrate protruding from the predetermined storage position to the front of the opening, Detecting the amount of sag of the substrate on which the end on the opening side hangs, and outputting the amount of protrusion and sag of the detected substrate ,
The collimator plate and the illuminating means are arranged such that an end portion on the opening side of the substrate housed in each slot is positioned in an optical path of planar light from the illuminating means toward the collimator plate. And
In the step of capturing an image of the end portion of the substrate on the opening side, the opening of the substrate accommodated in each slot formed on the collimator plate by light emitted in a planar shape from the illumination unit A substrate storage state detection method for capturing an image of an end portion on the side of a board.

Images