Mapping device and mapping method

Abstract

The invention provides a mapping device and a mapping method. The loading port (4) detects the accommodation state of the plurality of substrates (S), and the plurality of substrates (S) are accommodated in the FOUP (100) while being arranged in the thickness direction. The load port (4) includes a light emitter (62), a camera (61), and a controller (66). The controller (66) determines whether or not two or more substrates (S) are housed in a housing region in the imaging region (200), the housing region being a region for housing one of the plurality of substrates (S), by using change amount information of a plurality of pixel values that change in accordance with changes in coordinates of the substrates (S) in the thickness direction.

Description

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Japanese Patent Application No. 2024-158323, filed on September 12, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a mapping device and a mapping method. Background Technology

[0004] Patent Document 1 discloses a mapping device for determining the placement state of a substrate in a FOUP (Container for Upholstery). This mapping device determines the placement state of the substrate by utilizing imaging data (image information) acquired by a camera while the substrate end face is illuminated by an illumination device. More specifically, when the substrate thickness detected based on the imaging data is greater than the thickness of a single substrate, it is determined that the substrate is in a storage state where two or more substrates overlap (i.e., an overlapping state has occurred).

[0005] [Existing Technical Documents]

[0006] [Patent Literature]

[0007] Patent Document 1: Japanese Patent Publication No. 2024-60329

[0008] Although not disclosed in Patent Document 1, the following process can serve as an example of a specific process for detecting substrate thickness. First, in the image information, the pixel values ​​(representing brightness values) at each coordinate along the substrate thickness direction are compared with a preset threshold. If the pixel value at a certain coordinate is equal to or greater than the threshold, it is determined that a substrate exists at that coordinate. Furthermore, the length (i.e., thickness) in the thickness direction of the portion where the pixel value is equal to or greater than the threshold is compared with a reference thickness value to determine whether two or more substrates exist. Thus, it can be determined whether an overlapping state has occurred. However, in the above method of comparing the pixel value itself with the threshold, depending on the type of container, the influence of light reflected from the inner wall of the container may be significant, therefore, further improvements in detection accuracy may be needed. Summary of the Invention

[0009] This invention provides a technique for reliably detecting the containment state of a substrate.

[0010] The mapping apparatus according to the first configuration is a mapping apparatus for detecting the containment state of multiple substrates arranged along a predetermined thickness direction and contained in a container. The mapping apparatus includes: a light emitter configured to emit light at least into the interior of the container; an imager configured to image a predetermined imaging area by sensing reflected light emitted from the light emitter to acquire image information; and a determiner configured to determine the containment state of the substrates using the image information. The image information includes multiple pixel value information, which represent the intensity of reflected light at corresponding coordinates in the thickness direction; and the determiner uses information on the amount of change of the multiple pixel values ​​that varies with coordinates in the thickness direction to determine whether a containment area within the imaging area contains two or more substrates, the containment area being a region for containing one of the multiple substrates.

[0011] This configuration utilizes information about the change in pixel values ​​along the thickness direction for determination. Since the substrate is typically much thinner than the inner wall of the container, the pixel value corresponding to light reflected from the end face of the substrate changes rapidly with coordinate changes along the thickness direction. Conversely, because the inner wall surface of the container has a certain length along the thickness direction, light reflected from the inner wall surface can be detected over a wider area along the thickness direction. Therefore, it can be inferred that the change in pixel value corresponding to light reflected from the inner wall surface along the thickness direction is more gradual than the change in pixel value associated with the end face of the substrate. Thus, by using information about the change in pixel values ​​along the thickness direction, the influence of light reflected from the inner wall surface of the container can be suppressed during determination. Therefore, the container's containment state can be detected more reliably.

[0012] In the second configuration of the mapping device, the determiner can obtain numerical information representing one of the following: the number of peak values ​​of the pixel value, the number of times the pixel value starts to increase, and the number of times the pixel value stops decreasing, based on the change information, and count the number of substrates in the accommodating area based on the numerical information during the determination process.

[0013] Depending on the processing condition of the substrate's end face, the thickness of the portion of the end face that reflects light to the imager may be very small. Therefore, the detected substrate thickness value may be much smaller than the actual thickness. Even in this case, with this configuration, it is possible to determine the substrate's position by counting the number of substrates within the accommodating area. Therefore, the accommodating condition of the substrate can be detected more reliably.

[0014] In the third configuration of the mapping device, the determiner can utilize pixel value information in addition to change information during the determination process.

[0015] With this configuration, pixel value information can be used as auxiliary information for judgment. Therefore, compared with the case of using only pixel value change information, the accuracy of detecting the substrate accommodation state can be further improved.

[0016] The mapping method according to the fourth configuration is a mapping method executed in a mapping apparatus for detecting the containment state of multiple substrates, which are contained in a container while being arranged along a predetermined thickness direction. The mapping method includes: emitting light at least into the interior of the container; imaging a predetermined imaging area using reflected light from sensing light to acquire image information; and determining the containment state of the substrate using the image information, wherein the image information includes multiple pixel value information, these pixel values ​​representing the intensity of reflected light at corresponding coordinates in the thickness direction, and the determination step includes using information on the amount of change of the multiple pixel values ​​that changes with coordinates in the thickness direction to determine whether a containment area within the imaging area contains two or more substrates, the containment area being a region for containing one of the multiple substrates.

[0017] With this configuration, similar to the first configuration, the substrate's containment status can be detected more reliably. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention.

[0019] Figure 1 This is a schematic plan view of the EFEM and its surrounding environment, with the EFEM having a loading port according to this embodiment;

[0020] Figure 2 Right-side view of the loading port;

[0021] Figure 3 A schematic diagram illustrating the positional relationship between the substrate and the camera;

[0022] Figure 4 A schematic diagram of the imaging area captured by the camera;

[0023] Figure 5A and Figure 5B A schematic diagram illustrating the operation of the loading port;

[0024] Figure 6A and Figure 6B A schematic diagram illustrating the operation of the loading port;

[0025] Figure 7 To illustrate the flowchart of the entire mapping process;

[0026] Figure 8 A flowchart illustrating the decision-making process for each substrate is provided.

[0027] Figures 9A to 9D A schematic diagram illustrating the determination of the substrate accommodating state;

[0028] Figure 10 A schematic diagram illustrating an example of a set of pixel values;

[0029] Figure 11 This is a schematic diagram of a first-order differential filter;

[0030] Figure 12 This is a schematic diagram illustrating the set of differences obtained by applying a first-order differential filter to pixel values;

[0031] Figure 13 A schematic diagram illustrating the set of absolute values ​​of the differences;

[0032] Figure 14 A graph illustrating the relationship between pixel values ​​and the Y coordinate;

[0033] Figure 15 A graph showing the relationship between the difference and the Y-coordinate;

[0034] Figure 16 A graph showing the relationship between gradient intensity and the Y-coordinate;

[0035] Figure 17 A flowchart illustrating the overlap determination process;

[0036] Figure 18 A flowchart illustrating the overlap determination process according to a variant scheme;

[0037] Figure 19 A flowchart illustrating the overlap determination process according to another variant;

[0038] Figure 20 This is a schematic diagram illustrating a noise reduction filter according to yet another variant. Detailed Implementation

[0039] Various embodiments will be described in detail below, examples of which are shown in the accompanying drawings. In the following detailed description, numerous specific details will be set forth to provide a comprehensive understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without these specific details. In other instances, well-known methods, processes, systems, and components have not been described in detail to avoid unnecessarily obscuring the essential points of each embodiment.

[0040] Embodiments of the present invention (hereinafter referred to as "this embodiment") will now be described. For ease of description, Figure 1The directions shown are defined as front-back and left-right directions. Specifically, the direction in which EFEM 1 (described later) and processing device 6 (described later) are arranged side-by-side is defined as the front-back direction. In the front-back direction, the side where EFEM 1 is located is defined as the front side. In the front-back direction, the side where processing device 6 is located is defined as the rear side. The direction in which multiple loading ports 4 are arranged side-by-side and perpendicular to the front-back direction is defined as the left-right direction. The direction perpendicular to both the front-back and left-right directions is defined as the up-down direction. The up-down direction is the direction perpendicular to the direction of gravity.

[0041] (The overall structure of the loading port and its surrounding environment)

[0042] The following will refer to Figure 1 The loading port 4 (the mapping device of the present invention) and its surrounding environment according to this embodiment are described. Figure 1 This is a schematic diagram of EFEM 1 with loading ports 4 and its surrounding environment. "EFEM" is an abbreviation for "Equipment Front End Module". EFEM 1 is a device for transferring substrate S between the FOUP 100 (the container of the present invention) placed at each loading port 4 and the processing device 6. For example, a semiconductor circuit (not shown) is formed on the substrate S. Examples of substrate S types include well-known semiconductor substrates (including wafers), glass substrates, and glass epoxy plates. When viewed from above, substrate S is, for example, generally rectangular. Substrate S has, for example, an end face SE extending in the above-below direction (see...). Figure 2 ).

[0043] like Figure 1 As shown, EFEM 1 includes a housing 2, a transfer robot 3, multiple loading ports 4, and a control unit 5. The processing equipment 6 is located at the rear of EFEM 1.

[0044] EFEM 1 is installed at a predetermined location, for example, in a semiconductor factory. EFEM 1 transfers substrates S between FOUP 100 and processing equipment 6 using a transfer robot 3 located in the transfer space 9 within housing 2. FOUP 100 is placed on loading port 4. "FOUP" is an abbreviation for "Front-Opening Unified Pod". FOUP 100 is a container capable of holding multiple substrates S arranged vertically. FOUP 100 is transferred, for example, by a FOUP transfer device (not shown). FOUP 100 is transferred between the FOUP transfer device and loading port 4. The thickness direction of each substrate S is approximately parallel to the vertical direction.

[0045] The housing 2 forms a transfer space 9 for transferring the substrate S. The transfer space 9 is separated from the space outside the housing 2 (external space). Multiple loading ports 4 are connected to the front end of the housing 2. The loading locking chamber 7 of the processing device 6 is connected to the rear end of the housing 2. The transfer robot 3 transfers the substrate S between the FOUP 100 and the loading locking chamber 7.

[0046] Multiple loading ports 4 are arranged side-by-side, for example, in a left-right direction. Multiple loading ports 4 are attached to the front end of the housing 2. Each loading port 4 is configured to receive FOUP 100. Each loading port 4 is configured to load cover 102 (see...) Figure 2 ) Install the FOUP main body 101 to the FOUP 100 (see Figure 2 And disassembly thereof. Each loading port 4 is configured to map multiple substrates S contained in the FOUP body 101.

[0047] Control device 5 is electrically connected to the controller (not shown) of transfer robot 3, the loading port (LP) control device 46 of loading port 4 (described later), and the controller (not shown) of processing device 6. Control device 5 is configured to communicate with these controllers. Control device 5 can be electrically connected to host computer HC.

[0048] Processing equipment 6 is equipment for performing predetermined processes (such as film formation, etching, encapsulation, bonding, molding, etc.) on substrate S. Processing equipment 6 includes, for example, a loading and locking chamber 7 for temporarily holding substrate S and a processing chamber 8 for performing predetermined processes on substrate S.

[0049] (Loading port)

[0050] The following will refer to Figure 2 and Figure 3 Describe the configuration for loading port 4. Figure 2 This is the right-side view of the loading port 4. Figure 3 A schematic diagram illustrating the positional relationship between the substrate S and the plurality of cameras 61 described below (this positional relationship will be described below).

[0051] Loading port 4 removes the cover 102 of FOUP 100 from FOUP body 101 and maps the multiple substrates S housed within FOUP body 101. For example... Figure 2 As shown, loading port 4 includes, for example, a base 41, a door mechanism 42, a support frame 43, a stage 44, a scanner 45, and an LP control device 46 (see [reference]). Figure 1 ).

[0052] The base 41 is a generally flat, plate-like member. When viewed from the front-rear direction, the base 41 is generally rectangular. The base 41 is configured to extend vertically. The base 41 is fixed to EFEM 1. The base 41 is part of the partition wall separating the transfer space 9 from the external space. The base 41 has a generally rectangular opening 41a. The opening 41a is located in the upper part of the base 41. The size of the opening 41a allows the cover 102 of FOUP 100 to pass through in the front-rear direction. The opening 41a is opened and closed by the door 50 described below.

[0053] Door mechanism 42 attaches cover 102 to FOUP body 101 and removes cover 102 from FOUP body 101. For example... Figure 2 As shown, the door mechanism 42 includes, for example, a door body 50, a door support 53, a guide rail 54, a lifting block 55, a guide rail 56, a motor 57, and a motor 58.

[0054] The door body 50 is a plate-shaped component. When viewed from the front and rear, the door body 50 is generally rectangular. The door body 50 is supported, for example, by a door support member 53. The door body 50 is provided, for example, with a magnetic retainer (not shown) and a key (not shown). The magnetic retainer adheres to and holds the cover 102 on the front surface of the door body 50. The cover 102 is secured to the FOUP body 101 by a locking mechanism (not shown). The key operates the locking mechanism to lock and unlock the cover 102 of the FOUP 100.

[0055] Door support 53 is a component that supports door body 50. Door support 53 is supported by guide rail 54, allowing it to move in the front-to-back direction. Door support 53 is driven by motor 57 to move in the front-to-back direction. The front-to-back movement of door support 53 causes door body 50 to be in the closed position (see [link]). Figure 5B ) and opening location (see Figure 6A The door 50 moves between the closed and open positions. The closed position is the position where the door body 50 closes the opening 41a of the base 41. The open position is the position behind the closed position and the position where the door body 50 opens the opening 41a. The guide rail 54 is a component that guides the door support 53 in the front-to-back direction. The guide rail 54 is provided on the lifting block 55. The lifting block 55 is a component that moves the door body 50 in the vertical direction. The lifting block 55 supports the door support 53 so that it can move in the front-to-back direction. The lifting block 55 is guided in the vertical direction along the guide rail 56. The lifting block 55 is driven by the motor 58 to move in the vertical direction. The lifting block 55 moves in the vertical direction so that the door body 50 is in the above-mentioned open position (see above). Figure 6A ) and the retracted position below the open position (see Figure 6B The lifting block 55 moves between the two sides. The guide rail 56 is a component that guides the lifting block 55 in the vertical direction. The guide rail 56 is attached to the base 41, for example. The guide rail 56 extends in the vertical direction.

[0056] Motor 57 drives door support 53 to move in the front-to-back direction. Motor 57 is, for example, a well-known stepper motor. Motor 57 is controlled by LP control device 46. Motor 58 drives lifting block 55 to move in the vertical direction. Motor 58 is, for example, a well-known stepper motor. Motor 58 is configured to control the position of door support 53 in the vertical direction by means of control by LP control device 46.

[0057] The support frame 43 is a component that supports the platform 44. The support frame 43 is fixed to the base 41. The support frame 43 extends forward in the vertical direction from a portion of the base 41. The platform 44 is a platform-like component for placing the FOUP 100. The platform 44 is supported by the support frame 43. The platform 44 is configured to move relative to the support frame 43 in the front-rear direction. The platform 44 is moved by a drive mechanism (not shown) to a predetermined transfer position (see [reference]). Figure 5A ) and the cover opening / closing position behind the transfer position (see Figure 5B The FOUP 100 moves between the FOUP and the FOUP transport device (not shown). The transport position is the position of the platform 44 from which the FOUP 100 is transported.

[0058] Scanner 45 is a component used to inspect multiple substrates S within FOUP 100. For example, scanner 45 is disposed within transport space 9. For example, scanner 45 may be fixed to door 50. Therefore, scanner 45 is driven by motor 58 to move vertically together with door 50. Figure 3 As shown, the scanner 45 includes multiple cameras 61, a light emitter 62, a trigger sensor 65, and a controller 66 (i.e., the determiner of the present invention). The controller 66 may be disposed within the housing (not shown) of each camera 61.

[0059] Each of the plurality of cameras 61 is an apparatus for acquiring imaging data (i.e., image information of the present invention) of a plurality of substrates S. For example, each camera 61 is configured and set to image a plurality of substrates S at a time. The plurality of substrates S mentioned herein refers, for example, to a portion of all substrates S housed within the FOUP 100. Alternatively, each camera 61 may image a plurality of substrates S one at a time. Furthermore, in this embodiment, "imaging" refers to each camera 61 recording (i.e., capturing) an image of an object. Each camera 61 is configured and set to image a portion of the substrate S in a left-right direction. Each camera 61 is configured to image at least a portion of the end face SE (more specifically, the rear end face of the substrate S) of the substrate S. For example, the plurality of cameras 61 may be disposed on the upper side of the door 50 and arranged in a left-right direction. Each camera 61 is electrically connected to a controller 66. Each camera 61 includes, for example, a light-receiving lens 61a and an imaging element (not shown). The light-receiving lens 61a is a light-concentrating member configured to receive light and focus the light onto the imaging element. For example, the surface of the light-receiving lens 61a faces forward (FOUP side). The imaging element is a well-known device such as a CCD. The imaging element detects light, converts the light into an electrical signal, and transmits the electrical signal to the controller 66.

[0060] like Figure 3 As shown, the plurality of cameras 61 includes, for example, a first camera 63 and a second camera 64 (i.e., the imager of the present invention) different from the first camera 63. For example, the first camera 63 is a low-magnification camera with a large horizontal viewing angle. For simplicity, it is assumed that the first camera 63 in this embodiment is a monochrome camera, but the present invention is not limited thereto. The first camera 63 can also be a color camera. The horizontal viewing angle of the first camera 63 refers to the horizontal viewing angle that includes the area near the first rod P1 and the area near the second rod P2 in its field of view. As a specific example, when mapping a substrate S of, for example, 510mm × 515mm, the horizontal viewing angle can be 100 degrees or greater. More specifically, the horizontal viewing angle can be greater than 100 degrees and less than 150 degrees. The resolution of the first camera 63 is, for example, 2.3 megapixels. For example, the imaging axis of the first camera 61 is substantially parallel to the front-back direction (in other words, substantially horizontal). The horizontal viewing angle, resolution, and orientation of the imaging axis of the first camera 63 are not limited to the above description.

[0061] For example, the second camera 64 is a high-magnification camera with a horizontal viewing angle smaller than that of the first camera 63. For simplicity, it is assumed that the second camera 64 in this embodiment is a monochrome camera, but the invention is not limited thereto. The second camera 64 can also be a color camera. The horizontal viewing angle of the second camera 64 can be, for example, greater than 30 degrees and less than 35 degrees. In particular, the horizontal viewing angle can be greater than 34 degrees. The resolution of the second camera 64 is, for example, 2.3 megapixels. For example, the imaging axis of the second camera 64 is substantially parallel to the front-to-back direction (in other words, substantially horizontal). The horizontal viewing angle, resolution, and orientation of the imaging axis of the second camera 64 are not limited to those described above.

[0062] For example, the emitter 62 is an illumination device used to illuminate the interior of the FOUP 100. The emitter 62 includes, for example, multiple light sources 62A, 62B, and 62C (hereinafter also referred to as light sources 62A to 62C). Light sources 62A and 62B are light sources corresponding to the first camera 63. Light source 62C is a light source corresponding to the second camera 64. Each light source 62A to 62C includes, for example, an LED element (not shown). Light (illumination light) is emitted from the emitter 62 into the interior of the FOUP 100.

[0063] Part of the illumination light emitted from the light emitter 62 and propagating forward is reflected back by the substrate S or the inner wall surface 113 described below. This light is referred to hereinafter as reflected light. In particular, the substrate S is detected using the reflected light reflected from the end face SE (more specifically, the rear end face) of the substrate S. Partial illumination light (see...) Figure 3 The reflected light (the dashed line in the image) is reflected by the end face SE and then sensed by one of the multiple cameras 61. The imaging element of each camera 61 senses the reflected light to image a portion of the rear end face of the substrate S and its background in the left-right direction, thereby acquiring imaging data. The imaging data acquired by the imaging element is transmitted to the controller 66.

[0064] The trigger sensor 65 is a sensor used to determine when the multiple cameras 61 begin imaging. For example, the trigger sensor 65 may be configured to detect the movement of the door support 53 when a portion of the door support 53 moves in the vertical direction. The trigger sensor 65 sends a signal indicating the movement of the door support 53 to the controller 66.

[0065] Controller 66 is used to perform the mapping process described below. Controller 66 includes a CPU, ROM, and RAM (memory) not shown. Controller 66 performs calculations for the mapping process via the CPU according to a program stored in the ROM. Controller 66 is electrically connected to LP control device 46, multiple cameras 61, and trigger sensor 65. Controller 66 may have known internal storage devices not shown, such as known NAND flash memory, HDD, or SSD (not shown).

[0066] The LP control unit 46 includes a CPU, ROM, and RAM (memory), none of which are shown. The LP control unit 46 controls the various mechanisms of the load port 4 via the CPU according to the program stored in the ROM. The LP control unit 46 also communicates with the control unit 5 of EFEM 1, the host computer HC, etc. The LP control unit 46 also sends information related to mapping processing (described below) to the controller 66.

[0067] (FOUP)

[0068] Next, we will refer to Figure 2 and Figure 3 A more specific example describing the configuration of FOUP 100. Figure 3 The front-back and left-right directions shown are for ease of explanation when the opening 114 (described below) faces rearward. It should be noted that... Figure 3 The left and right directions shown are Figure 3 The left and right directions on the paper are reversed.

[0069] FOUP 100 is a container that is roughly rectangular in shape. FOUP 100 can accommodate multiple substrates S arranged vertically. For example... Figure 2 and Figure 3 As shown, FOUP 100 includes a FOUP body 101 and a cover 102. The FOUP body 101 is a generally cuboid-shaped component. The FOUP body 101 can be supported by a stage 44. For example, the FOUP body 101 has a wall 111, an opening 112, and a plurality of rods P.

[0070] Wall 111 is a generally cuboid-shaped component arranged to surround the interior space of FOUP 100. For example, wall 111 is formed by fixing multiple generally flat components together using a fastening tool (not shown). Wall 111 has multiple inner wall surfaces 113 (see...). Figure 2 and Figure 3 For example, the opening 112 is provided at the rear end of the FOUP body 101. The opening 112 has an opening 114 that is generally rectangular when viewed from the front-rear direction.

[0071] Each of the plurality of inner wall surfaces 113 is configured to face the interior of FOUP 100. For example, each inner wall surface 113 is generally rectangular. The plurality of inner wall surfaces 113 includes a rear surface 113B, a top surface 113U (see [reference]). Figure 2 ), lower surface 113D (see Figure 2 ), left side 113L (see Figure 3 ) and right side 113R (see Figure 3 The rear surface 113B is the inner wall surface 113 located at the foremost of the plurality of inner wall surfaces 113. Figure 3 In the FOUP body 101, the rear surface 113B faces rearward (i.e., the side of the opening 114 in the front-rear direction). The rear surface 113B extends in both vertical and horizontal directions. The rear surface 113B is positioned across the center of the FOUP body 101 in the front-rear direction, opposite to the opening 114. The upper surface 113U is connected to the upper end of the rear surface 113B and extends in the front-rear direction to the rear end of the FOUP body 101. The upper surface 113U faces downward. The lower surface 113D is connected to the lower end of the rear surface 113B and extends in the front-rear direction to the rear end of the FOUP body 101. The lower surface 113D faces upward. The left side surface 113L is connected to the left end of the rear surface 113B, the left end of the upper surface 113U, and the left end of the lower surface 113D, and extends in the front-rear direction to the rear end of the FOUP body 101. The left side surface 113L faces right. The right side surface 113R connects to the right end of the rear surface 113B, the right end of the upper surface 113U, and the right end of the lower surface 113D, and extends in the front-rear direction to the rear end of the FOUP body 101. The right side surface 113R faces the left side.

[0072] Multiple rods P support multiple substrates S approximately horizontally. The rods P are positioned within the space surrounded by the FOUP body 101. For example, each of the rods P extends in a front-to-back direction. For example, each of the rods P is fixed to the rear surface 113B. A portion of the substrate S is placed on any one of the rods P. Figure 2 As shown, multiple rods P are arranged corresponding to multiple substrates S in the vertical direction. Furthermore, as... Figure 3 As shown, multiple rods P are arranged side-by-side in the left-right direction. The multiple rods P include multiple first rods P1, multiple second rods P2, and multiple third rods P3. For example, multiple first rods P1 are located immediately adjacent to the left side of the right side 113R and are arranged vertically. For example, multiple second rods P2 are located approximately at the center of the FOUP body 101 in the left-right direction and are arranged vertically. For example, multiple third rods P3 are located near the left side 113L and are arranged vertically. The first rods P1, second rods P2, and third rods P3 are arranged to correspond one-to-one with a substrate S. The space used to support a substrate S is called a slot or pocket (hereinafter referred to as a slot for ease of explanation). The slot corresponds to the receiving area of ​​the present invention. The FOUP 100 has multiple slots arranged vertically. The number of rods P supporting each substrate S is not limited to three.

[0073] The cover 102 is configured to open and close the opening 114. The cover 102 is attached to and detached from the FOUP body 101 via the loading port 4. The cover 102 has a locking mechanism (not shown) capable of changing the state of the cover 102 between a state where the cover 102 is secured to the FOUP body 101 and a state where the cover 102 is released from the FOUP body 101. The locking mechanism is locked and unlocked using a key (not shown).

[0074] (Camera Setup Overview)

[0075] Reference Figure 3 and Figure 4 An overview of the arrangement of camera 61 is provided. Figure 3 The positional relationship between the multiple cameras 61 and the FOUP 100 is shown when the multiple cameras 61 image the substrate S. Figure 4 This is a schematic diagram showing multiple imaging regions 200 (first imaging region 201 and second imaging region 202).

[0076] like Figure 3 As shown, for example, a first camera 63 is positioned in the left-right direction between the first rod P1 and the second rod P2. The first camera 63 is positioned such that reflected light from the end face SE near the first rod P1 and reflected light from the end face SE near the second rod P2 are directed towards the first camera 63. The first camera 63 is configured and set to focus on the first imaging area 201 (see...). Figure 4 Imaging is performed, and the first imaging region 201 is one of multiple imaging regions 200. For example... Figure 4 As shown, the length of the first imaging region 201 in the vertical direction is, for example, greater than the length obtained by adding the diameter of the rod P to the thickness of the substrate S. For example, the first imaging region 201 extends from the right side of the first rod P1 to the left side of the second rod P2 in the horizontal direction.

[0077] Data associated with determination regions 210 (first determination region 211 and second determination region 212), which are part of the first imaging region 201, is used as determination data to determine the containment state of the substrate S. The first determination region 211 is the region near the first rod P1. The second determination region 212 is the region near the second rod P2. For ease of explanation, the determination data associated with the first determination region 211 is referred to as first determination data. The determination data associated with the second determination region 212 is referred to as second determination data. The first determination data and the second determination data are collectively referred to as low-magnification data.

[0078] like Figure 3As shown, for example, a second camera 64 is arranged in the left-right direction between the second rod P2 and the third rod P3. The second camera 64 is positioned so that reflected light from the end face SE mirror located near the third rod P3 is directed towards the second camera 64. For example, the distance between the second camera 64 and the third rod P3 in the left-right direction may be shorter than the distance between the second camera 64 and the second rod P2 in the left-right direction. The second camera 64 is configured and set to focus on the second imaging area 202 (see...). Figure 4 Imaging is performed, and the second imaging region 202 is one of multiple imaging regions 200. For example... Figure 4 As shown, the length of the second imaging region 202 in the vertical direction is, for example, greater than the length obtained by adding the diameter of the rod P to the thickness of the substrate S. More specifically, the length of the second imaging region 202 in the vertical direction is, for example, greater than the length obtained by adding the diameter of the rod P to the thickness of both substrates S. For example, the second imaging region 202 is pre-set by taking into account the design tolerance of the rod P's dimensions. For example, the second imaging region 202 extends from the right side of the third rod P3 to the left side of the third rod P3 in the horizontal direction. However, the present invention is not limited to the above description. The third rod P3 is not necessarily included in the horizontal field of view of the second camera 64.

[0079] Data associated with the determination region 210 (third determination region 213), which is part of the second imaging region 202, is used as determination data to determine the accommodating state of the substrate S. The third determination region 213 is the region near the third rod P3. In the following text, for ease of explanation, the determination data associated with the third determination region 213 is referred to as third determination data. In this embodiment, the third determination data is also referred to as high-magnification data. The third determination data corresponds to the image information in this invention.

[0080] (Details of camera and light source setup)

[0081] Reference Figure 3 and Figure 4 A more detailed description is given of the arrangement of camera 61 and light sources 62A to 62C. For example... Figure 3 As shown, when camera 61 images the imaging area 200, camera 61 focuses reflected light through light-receiving lens 61a. Generally, depending on the lens specifications, the principal points (front principal point and rear principal point), focal points (front focal point and rear focal point), and nodal points (front nodal point and rear nodal point) of the lens are predetermined. Although not shown in the figure, in this embodiment, for ease of explanation, for example, the front nodal point (the center point of the surface of light-receiving lens 61a on the substrate S side) of light-receiving lens 61a is defined as light-receiving point RP. The light-receiving point RP associated with the first camera 63 is called the first light-receiving point RP1. The light-receiving point RP associated with the second camera 64 is called the second light-receiving point RP2.

[0082] In addition, such as Figure 4 As shown, for ease of explanation, the predetermined point contained in each determination region 210 and located on the end face SE is referred to as the detection target point SP (see [reference]). Figure 3 and Figure 4 The positions of the detection target points SP in the left-right and front-back directions are preset according to, for example, the specifications of FOUP 100, the specifications of the substrate S, the arrangement of the light emitters 62, and the configuration and arrangement of the camera 61. The detection target points SP included in the first determination area 211 are called the first detection target points SP1. Figure 3 As shown, the first detection target point SP1 can be located, for example, to the left of the first rod P1 (i.e., inside the first rod P1 in the left-right direction). The detection target point SP contained in the second determination area 212 is called the second detection target point SP2. Figure 3 As shown, the second detection target point SP2 can, for example, be located at approximately the same position as the center of the second rod P2 in the left-right direction. The detection target point SP contained in the third determination area 213 is called the third detection target point SP3. Figure 3 As shown, the third detection target point SP3 may be located, for example, to the right of the third rod P3 (i.e., inside the third rod P3 in the left-right direction). The position of each detection target point SP is not limited to the above description. For example, one or more detection target points SP may be directly set above the corresponding rod P. The first camera 63 images the imaging area 200 (first imaging area 201, see [link]) containing the first detection target point SP1 and the second detection target point SP2. Figure 4 The second camera 64 performs imaging on the imaging region 200 (second imaging region 202, see [reference]) containing the third detection target point SP3. Figure 4 (to perform imaging)

[0083] like Figure 3 As shown, for ease of explanation, the virtual straight line passing through the predetermined light-receiving point RP and the predetermined detection target point SP is called the virtual straight line VL. More specifically, the virtual straight line VL passing through the first light-receiving point RP1 and the first detection target point SP1 is called the first virtual straight line VL1. The virtual straight line VL passing through the first light-receiving point RP1 and the second detection target point SP2 is called the second virtual straight line VL2. The virtual straight line VL passing through the second light-receiving point RP2 and the third detection target point SP3 is called the third virtual straight line VL3. The first virtual straight line VL1 intersects, for example, the right side 113R of FOUP 100. The second virtual straight line VL2 and the third virtual straight line VL3 intersect, for example, the left side 113L of FOUP 100.

[0084] (Basic operations for loading ports)

[0085] The following will combine Figures 5A to 6B The basic operation of loading port 4 is explained. Figures 5A to 6B This is the right-side view of the loading port 4 during operation.

[0086] First, place the FOUP 100 on stage 44 (see...). Figure 5A The LP control unit 46 moves the stage 44 from the transfer position (see...). Figure 5A Move to the open / closed position of the lid (see...) Figure 5B Subsequently, the LP control device 46 adheres to and holds the cover 102 on the suction holder of the door 50, and unlocks the locking mechanism of the cover 102 using a key. The LP control device 46 then controls the motor 57 to move the door support 53 backward (see...). Figure 6A (The right arrow in the diagram). Thus, door 50 moves from the preset closed position (see...). Figure 5B Move to the open position (see) Figure 6A Therefore, the cover 102 is removed from the FOUP body 101.

[0087] Subsequently, the LP control device 46 controls the motor 58 to move the door 50 from the open position (see...). Figure 6A Move to the retracted position (see...) Figure 6B Accordingly, the multiple cameras 61 and other components of the scanner 45 move downward along with the door 50. In response to a command from the controller 66, the multiple cameras 61 position themselves at predetermined locations in the vertical direction for a predetermined imaging area 200 (see [link]). Figure 4 Imaging is performed to acquire imaging data. Imaging region 200 includes multiple determination regions 210 for determining the accommodating state of substrate S (see [reference]). Figure 4 (Specific details will be described below). The controller 66 performs mapping processing based on the imaging data acquired by multiple cameras 61 (specific details will be described below).

[0088] After the mapping process is completed, the transfer robot 3 begins transferring the substrate S between the FOUP 100 and the processing device 6. The processing device 6 sequentially performs predetermined processing on some or all of the substrates S. The processed substrates S are then returned to the FOUP 100 by the transfer robot 3. Once all substrates S have been returned to the FOUP 100, the LP control device 46 causes components such as the door mechanism 42 to perform the opposite operation to opening the cover 102, and attaches the cover 102 to the FOUP body 101. As described above, a series of processes are performed from the time the FOUP 100 is transferred to the loading port 4 until the FOUP 100 can be unloaded from the loading port 4.

[0089] (Mapping Processing)

[0090] Next, we will mainly refer to Figure 7 An example of the mapping process (mapping method) performed by load port 4 is illustrated. Figure 7The flowchart illustrates the entire mapping process.

[0091] The initial state is as follows: FOUP 100, containing multiple substrates S, is placed on stage 44. Stage 44 is in the open / closed position. The cover 102 of FOUP 100 is opened by door mechanism 42. Door 50 is in the open position (see...). Figure 6A ).

[0092] First, the LP control device 46 sends information (planning information) related to the imaging plan executed by the camera 61 to the controller 66. For example, the planning information includes the specifications of the FOUP 100, the number of substrates S that can be stored in the FOUP 100, the position of the highest slot among the multiple slots of the FOUP 100, the set value of the descent speed of the gate 50, etc. The planning information is sent to the LP control device 46 in advance, for example, from the controller (not shown) of the processing device 6. The controller 66 receives the planning information from the LP control device 46. Figure 7 (See step S101). The controller 66 calculates the imaging plan based on the planning information (step S102). The imaging plan refers to the time arrangement for the camera 61 to perform imaging after the controller 66 receives a predetermined trigger signal and a certain period of time has elapsed.

[0093] Subsequently, the LP control device 46 controls the motor 58 of the door mechanism 42 to begin lowering the scanner 45 together with the door body 50 (and the door support 53) (step S103). At this time, the trigger sensor 65 detects that the door support 53 has begun to move and sends a detection signal to the controller 66. The controller 66 receives this detection signal as a trigger signal (step S104). Thereafter, the controller 66 causes each camera 61 to image based on the imaging plan, for example, according to the following procedure. The controller 66 causes the light sources 62A to 62C to emit light at least when each camera 61 is imaging (light emission step).

[0094] The controller 66 sets the counter to an initial value to count (determine) the substrates S housed in the FOUP 100 one by one, starting from the top. Specifically, the controller 66 inputs, for example, "1" to a predetermined variable N (step S105).

[0095] Subsequently, the controller 66 determines, based on the imaging plan, whether the timing for imaging the Nth substrate S has arrived (step S106). If the timing for imaging the Nth substrate S has not arrived (step S106: "No"), the LP control device 46 continues to lower the scanner 45. If the timing for imaging the Nth substrate S has arrived (step S106: "Yes"), the controller 66 controls multiple cameras 61 to image the imaging region 200 associated with the Nth substrate S and acquire imaging data associated with that substrate S (imaging step, step S107). Specifically, the controller 66 causes the first camera 63 to image the first imaging region 201 and the second camera 64 to image the second imaging region 202. The controller 66 temporarily stores the imaging data acquired by these cameras 61, for example, in a memory. Furthermore, the controller 66 may also store the imaging data in, for example, an internal memory not shown above.

[0096] Subsequently, the controller 66 determines the containment state of the Nth substrate S based on the determination data contained in the imaging data (determination step, step S108). The specific details of the determination step (the determination step of the present invention) will be described below.

[0097] Subsequently, the controller 66 determines whether the determination process for all substrates S has been completed (step S109). If the controller 66 determines that there are substrates S that have not yet been determined (step S109: "No"), the controller 66 increments the variable N by "1" (step S110) and returns to step S106. If the determination process for all substrates S has been completed (step S109: "Yes"), the controller 66 ends the mapping process.

[0098] (Decision Processing)

[0099] The following will refer to Figures 8 to 9D An example of the determination process for determining the containment state of each substrate S will be explained. Figure 8 A flowchart illustrating the determination process for each substrate S is provided. Figures 9A to 9D This is a schematic diagram used to explain the determination of the accommodating state of the substrate S. In summary, the controller 66 determines whether the accommodating state of the Nth substrate S is overlapping or intersecting, whether the Nth substrate S exists, or whether the Nth substrate S is properly accommodated. In the following determination process, the controller 66 uses data related to the determination area 210 of the imaging area 200 as determination data.

[0100] First, the controller 66 determines whether the accommodating state of the Nth substrate S is an overlapping state (overlap determination); Figure 8 Step S201 is shown in the figure. Figure 9AAs shown, an overlapping state refers to the state in which two (or more) substrates S that overlap each other in the vertical direction are accommodated in a slot. The overlap determination will be described in detail below. If an overlapping state is detected (step S202: "Yes"), the controller 66 stores information indicating that the accommodation state of the Nth substrate S is an overlapping state in the memory (step S203). Thereafter, the controller 66 ends the determination of the Nth substrate S.

[0101] If no overlap is detected (step S202: "No"), the controller 66 determines whether the accommodation state of the Nth substrate S is a cross-state (cross-state determination). For example, as Figure 9B or Figure 9C As shown, the cross state refers to a state in which a part of the substrate S is placed on one of a pair of rods P arranged in the left-right direction, while the other part of the substrate S is located below the pair of rods P.

[0102] As part of the cross-determination process, firstly, the controller 66 determines, for example, whether the accommodation state of the Nth substrate S is in a cross-state based on low-magnification data (step S204). Specifically, the controller 66 compares the position of the substrate S in the vertical direction (hereinafter referred to as the first substrate position) detected based on the first determination data with the set position in the vertical direction corresponding to the first rod P1 of the substrate S (hereinafter referred to as the first set position). For example, when the first substrate position is lower than the first set position, the controller 66 determines that the accommodation state of the Nth substrate S is in a cross-state (i.e., a cross-state is detected).

[0103] Furthermore, the controller 66 compares the position of the substrate S in the vertical direction detected based on the second determination data (hereinafter referred to as the second substrate position) with the set position of the second rod P2 corresponding to the substrate S in the vertical direction (hereinafter referred to as the second set position). The second set position can be set to the same position in the vertical direction as the first set position, or it can be set independently of the first set position. For example, if the second substrate position is lower than the second set position, the controller 66 determines that the accommodation state of the Nth substrate S is a cross state (i.e., a cross state is detected). If a cross state is detected (step S205: "Yes"), the controller 66 stores the information indicating that the accommodation state of the Nth substrate S is a cross state in the memory (step S206). Thereafter, the controller 66 ends the determination of the Nth substrate S.

[0104] When no crossover state is detected based on low-magnification data (step S205: "No"), the controller 66 performs a crossover determination by considering high-magnification data (step S207). The controller 66 compares the position of the substrate S in the vertical direction (hereinafter referred to as the third substrate position) detected based on the third determination data with the set position in the vertical direction of the third rod P3 corresponding to the substrate S (hereinafter referred to as the third set position). The third set position may be the same position in the vertical direction as the first set position and / or the second set position, or it may be set independently of the first set position and the second set position. For example, when the third substrate position is lower than the third set position, the controller 66 determines that the accommodation state of the Nth substrate S is a crossover state (i.e., a crossover state is detected). When a crossover state is detected (step S208: "Yes"), the controller 66 executes the above step S206 and ends the determination of the Nth substrate S.

[0105] When no crossover is detected even after considering high-magnification data (step S208: "No"), the controller 66 determines whether the substrate S exists (step S209). Specifically, the controller 66 determines whether the substrate S is detected in any of the first determination region 211, the second determination region 212, and the third determination region 213 based on the determination data. When the substrate S is not detected in any determination region 210 (see step S209), the controller determines whether the substrate S exists in any of the determination regions 210. Figure 9D If the controller 66 determines that the Nth substrate S has not been preset (step S210: "No"), then the controller 66 stores the information indicating that the Nth substrate S has not been preset in the memory (step S211). After this, the controller 66 ends the determination of the Nth substrate S. If a substrate S is detected in any determination area 210, the controller 66 determines that the Nth substrate S has been preset (i.e., correctly stored) (step S211: "No"). In this case, the controller 66 directly ends the determination of the Nth substrate S. As described above, the determination process for the Nth substrate S is complete.

[0106] Here, the inventors of this invention have been researching ways to further improve the detection accuracy of the aforementioned overlapping state. As a specific example of a conventional method for determining overlap, one approach is to compare the pixel value (called luminance) of the pixel at each coordinate in the thickness direction (vertical direction) of the substrate S in the third determination data with a preset threshold. In this method, if the pixel value of a pixel corresponding to a certain coordinate is equal to or greater than the threshold, it is determined that the substrate S exists at that coordinate. Furthermore, the presence of two or more substrates S is determined by comparing the length (i.e., thickness) of the portion where the pixel value is equal to or greater than the threshold in the thickness direction with a thickness reference value. However, in the method of comparing the pixel value itself with the threshold, the light reflected from the inner wall surface 113 of the FOUP 100 has a significant impact, depending on the type of FOUP 100. Therefore, further improvements in detection accuracy may be needed.

[0107] Furthermore, in the method of comparing the detected thickness value of the substrate S with a reference value, the following problem may occur. Depending on the processing state of the end face SE of the substrate S, the length of the portion of the end face SE that reflects light to the second camera 64 in the thickness direction may be significantly shorter than the actual length (i.e., thickness) in the thickness direction of the substrate S. In this case, even if two or more substrates S overlap each other, the detected thickness value of the substrate S may not exceed the reference value, resulting in a judgment error.

[0108] Therefore, in order to detect the overlap state more reliably, the controller 66 of this embodiment performs the following overlap determination (the determination of the present invention).

[0109] (Details of overlap determination)

[0110] The following will refer to Figures 10 to 17 The details of the overlap determination are explained. Figure 10 This is a schematic diagram showing an example of a set of pixel values, that is, an example of pixel values ​​at each coordinate in the third determination data. Figure 11 This is a schematic diagram of a first-order differential filter. Figure 12 This is a schematic diagram showing the set of differences obtained after applying a first-order differential filter to pixel values. Figure 13 This is a schematic diagram showing the set of absolute values ​​of the differences (also known as gradient strengths). Figures 10 to 13 In this embodiment, the left-right direction (X-coordinate direction) on the paper corresponds to the left-right direction, and the up-down direction (Y-coordinate direction) on the paper corresponds to the up-down direction. Figure 14 It is a graph showing the relationship between pixel values ​​and the Y coordinate (described in detail below). Figure 15 It is a graph showing the relationship between the difference and the Y-coordinate. Figure 16 It is a graph showing the relationship between gradient strength (the absolute value of the difference) and the Y-coordinate. Figure 17This is a flowchart illustrating the overlap determination process.

[0111] The controller 66 performs overlap determination, for example, by using third determination data. The third determination data is a set of multiple pixel values ​​associated with two-dimensional coordinates, wherein the two-dimensional coordinates consist of an X-coordinate corresponding to the left-right direction and a Y-coordinate corresponding to the up-down direction. Figure 10 Multiple boxes are shown in matrix form. Numbers ("1" to "6") arranged horizontally above the boxes represent the X-coordinate. Figure 10 The numbers ("1" to "19") arranged vertically on the left side of the multiple boxes shown represent the Y-coordinates. The numbers written inside each box represent the pixel values ​​associated with those coordinates. Each pixel value is an integer ranging from 0 to 255. The larger the pixel value, the brighter the corresponding position. The multiple numbers written outside the boxes are coordinates added for ease of explanation. It should be noted that... Figure 10 The pixel values ​​shown are convenient values ​​set for the purpose of explaining this embodiment and may not necessarily be consistent with the actual pixel values ​​obtained by the second camera 64. For ease of explanation, Figure 10 The pixel values ​​shown are constant and do not depend on the X coordinate. The pixel values ​​only change with the Y coordinate. In the following text, the direction along the X coordinate (left and right) will also be referred to as the X direction, and the direction along the Y coordinate (up and down) will also be referred to as the Y direction.

[0112] First, the controller 66 performs first-order differential processing on the third decision data in the Y direction, for example, to generate a first-order differential image. Figure 17 Step S301 shown in the diagram. More specifically, controller 66, for example, uses a well-known first-order differential filter (see step S301). Figure 11 This is applied to the third decision data. The first-order differential filter is a first-order differential filter related to the Y-coordinate. Therefore, a set of multiple differences associated with multiple coordinates can be obtained (see...). Figure 12 In this embodiment, the difference is the difference between a pixel value associated with a certain coordinate of the third determination data and a pixel value associated with the immediately preceding coordinate in the Y direction. In this invention, the difference information corresponds to the amount of change that varies with the coordinate along the thickness direction. Furthermore, the difference cannot be obtained at coordinates corresponding to X=1 or Y=1 (see [link to documentation]). Figure 12 For ease of explanation, the set of differences will also be referred to as the first-order differential image below.

[0113] Subsequently, controller 66 acquires data of the set of absolute values ​​of the differences corresponding to each coordinate (see...). Figure 13 In the following text, for ease of explanation, the absolute value of the difference is also referred to as the gradient intensity. That is, the controller 66 acquires the gradient intensity information (step S302). In this invention, the gradient intensity also corresponds to the amount of change that varies with the coordinates along the thickness direction.

[0114] Figure 14 The graph shows the relationship between pixel values ​​and the Y-coordinate. The pixel value at each Y-coordinate can be, for example... Figure 10 The average of multiple pixel values ​​arranged along the X-direction. Alternatively, the pixel value can also be, for example, a value obtained by extracting only the pixel value associated with a specific X coordinate along the Y-direction. Furthermore, for reference, Figure 15 The graph shows the relationship between the difference and the Y-coordinate. Furthermore, Figure 16 The graph shows the relationship between gradient intensity and the Y-coordinate. Figure 16 It also includes a graph showing the relationship between pixel values ​​and the Y coordinate (see double-dotted line).

[0115] For example, controller 66 pre-stores threshold information of pixel values ​​(see Figure 14 The value of Tp is shown in the diagram. For example, 40. The controller 66 also pre-stores threshold information for the gradient intensity (see...). Figure 16 The value of Tg is shown in the figure. For example, Tg is 50.

[0116] Controller 66, for example, uses gradient intensity data and third decision data to determine the third decision region 213 (see...). Figures 9A to 9D The number of substrates S within the array is counted. More specifically, the controller 66 determines, for example, whether the gradient intensity is equal to or greater than Tg in ascending order of the Y coordinate (this determination process is commonly referred to as scan line processing along the Y direction). In other words, in this embodiment, the controller 66 detects the start of an increase in pixel value. This will be explained in more detail below.

[0117] The controller 66 sets the number of substrates S detected to zero (M = 0; see step S303). The controller 66 also sets the Y coordinate to "2" (Y = 2; see step S303). These processes are the initial setting processes for counting the number of substrates S housed in the Nth slot.

[0118] Controller 66 determines whether the gradient intensity at the Y-coordinate to be determined is equal to or greater than Tg (step S304). When the gradient intensity is less than Tg (step S304: "No"), controller 66 updates the Y-coordinate (Y = Y + 1; step S305) and determines whether Y is a preset maximum value (step S306). The maximum value refers to the maximum Y-coordinate related to the pixel value in the determination area related to the third determination data (the same applies below). In addition, the value obtained by subtracting one from the maximum value (hereinafter referred to as "maximum value - 1") is the maximum Y-coordinate related to the gradient intensity (and difference). When Y is not the maximum value (step S306: "No"), controller 66 returns to step S304. When Y is the maximum value (step S306: "Yes"), the overlap determination of the Nth slot (counting the number of substrates S) ends.

[0119] Returning to the description of step S304, when the gradient intensity is equal to or greater than Tg (step S304: "Yes"), the controller 66 increments the detection count of substrate S by 1 (M = M + 1; step S307). Subsequently, the controller 66 updates the Y coordinate in the same manner as in step S305 (step S308). Afterward, the controller 66 determines whether Y is the maximum value in the same manner as in step S306 (step S309). When Y is the maximum value (step S309: "Yes"), the counting of substrate S is stopped. When Y is not the maximum value (step S309: "No"), the controller 66 determines whether the pixel value is less than Tp (step S310). When the pixel value is equal to or greater than Tp (step S310: "No"), the controller 66 returns to step S308 and repeats the update of the Y coordinate. This is to prevent detected substrates S from being counted repeatedly. When the pixel value is less than Tp (step S310: "Yes"), the controller 66 returns to step S304. A pixel value less than Tp indicates that the detection of substrate S has been interrupted. Returning to step S304 means preparing to count the next substrate S. Through the above process, the overlap determination of this embodiment is performed.

[0120] By performing the above determination, the number of substrates S can be detected based on the number of times the pixel value rise begins (see [reference]). Figure 16 (Circle markers on the solid line curve). The number of times the pixel value increase was detected corresponds to the numerical information of this invention.

[0121] As described above, this determination is made using information about the amount of pixel value change along the thickness direction. Since the substrate S is typically very thin compared to the inner wall surface 113 of the FOUP 100, the pixel value corresponding to the light reflected from the end face SE of the substrate S changes rapidly with coordinate changes in the thickness direction. Conversely, since the inner wall surface 113 of the FOUP 100 has a certain length in the thickness direction, the light reflected from the inner wall surface 113 of the FOUP 100 can be detected over a larger area in the thickness direction. Therefore, it can be inferred that the amount of pixel value change in the thickness direction corresponding to the light reflected from the inner wall surface 113 is more gradual than the amount of pixel value change associated with the end face SE of the substrate S. Therefore, by using information about the pixel value change in the thickness direction, the influence of light reflected from the inner wall surface 113 of the FOUP 100 can be suppressed during overlap determination. Therefore, the overlap state (substrate accommodation state) can be detected more reliably.

[0122] Furthermore, overlap determination can also be performed by calculating the number of substrates S in each slot. Therefore, overlap can be detected more reliably.

[0123] Furthermore, pixel value information can serve as auxiliary information in overlap determination. Therefore, compared to using only pixel value change information, the accuracy of overlap state detection can be further improved.

[0124] Next, variations of the above embodiments will be described. Components identical to those in the embodiments will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0125] (1) In the above embodiment, the controller 66 calculates the number of times the pixel value begins to rise. However, the present invention is not limited thereto. The controller 66 may not perform the processing described in the above embodiment, but instead calculate the number of times the pixel value stops falling. The following will refer to... Figure 18The flowchart shown will be explained in detail. First, the controller 66 generates a first-order differential image (step S401) and acquires gradient intensity information in the same manner as in the above embodiment (step S402). The controller 66 also sets the detection count of the substrate S to zero and sets the Y coordinate to "2" (step S403). Then, the controller 66 determines whether the gradient intensity is greater than or equal to Tg (step S404). When the gradient intensity is greater than or equal to Tg (step S405: "Yes"), the controller 66 further determines whether the pixel value is less than Tp (step S405). When the pixel value is less than Tp (step S405: "Yes"), the controller 66 increments the detection count of the substrate S by 1 (step S406). That is, the pixel value descent is only counted when the gradient intensity is greater than or equal to Tg and the pixel value is less than Tp. Then, the controller 66 determines whether Y is the above "maximum value - 1" (step S407). When Y is not "maximum value - 1" (step S407: "No"), controller 66 updates the Y coordinate (step S408) and returns to step S404. When Y is "maximum value - 1" (step S408: "Yes"), the overlap determination ends.

[0126] By performing the above determination, the number of substrates S can be detected based on the number of times the detected pixel value decrease ends (see...). Figure 16 (Square markers on the solid line curve). In this variant, the number of times the detected pixel value decrease ends corresponds to the numerical information of this invention.

[0127] (2) In the above embodiments and their variations, the controller 66 calculates the number of times the pixel value begins to rise or the number of times the pixel value stops falling. However, the present invention is not limited thereto. The controller 66 can calculate the number of peak pixel values ​​in the following manner. Referring below... Figure 19The flowchart shown will be explained in detail. First, the controller 66 generates a first-order differential image in the same manner as in the above embodiment (step S501). However, the controller 66 may not acquire gradient intensity information. In addition, the controller 66 sets the Y coordinate to "2" (step S502). However, at this stage, the controller 66 may not set the number of detections of the substrate S to zero. The controller 66 selects peak candidates for pixel values ​​in the following steps S503 to S506. For ease of explanation, the difference at each Y coordinate is defined as D(Y). In addition, for ease of explanation, the function representing whether a peak candidate for a pixel value has been found at each Y coordinate is defined as C(Y). The controller 66 determines whether the pixel value is greater than or equal to Tp (step S503). When the pixel value is greater than or equal to Tp (step S503: "Yes"), the controller 66 further determines whether the product of D(Y) and D(Y+1) is less than or equal to zero (step S504). The product of D(Y) and D(Y+1) being less than or equal to zero means that the pixel value changes from increasing to decreasing according to the change in the Y coordinate (see...). Figure 14 and Figure 15 In other words, it can be inferred that the peak value of the pixel has been found. When the product of D(Y) and D(Y+1) is less than or equal to zero (step S504: "Yes"), the controller 66 sets the value of C(Y) to "1" (step S505). When the determination result of step S503 or step S504 is "No", the controller 66 sets the value of C(Y) to "0" (step S506). C(Y) being "1" indicates that a peak value candidate of the pixel value has been found at this Y coordinate. C(Y) being "0" indicates that no peak value of the pixel value has been found at this Y coordinate. Subsequently, the controller 66 determines whether Y is "maximum value - 1" (step S507). When Y is not "maximum value - 1" (step S507: "No"), the controller 66 updates the Y coordinate (step S508) and returns to step S503. When Y is "maximum value - 1" (step S507: "Yes"), the controller 66 proceeds to the next step (see Figure 19 (The circled "A").

[0128] In the following steps and after this step, the controller 66 verifies whether the peak candidate of the pixel value is a true peak and calculates the number of true peaks. In this variant, the number of true peaks corresponds to the numerical information of the present invention. First, the controller 66 sets the detection count of the substrate S to zero and sets the Y coordinate to, for example, "3" (step S509). The reason for setting the initial value of the Y coordinate to "3" during verification will be explained later. Then, the controller 66 determines whether C(Y) is "1" (step S510). When C(Y) is "1", the controller 66 further determines whether C(Y-1) is "0" (step S511). Only when the determination result of step S511 is "yes" does the controller 66 add "1" to the detection count of the substrate S (step S512). The reason is as follows. That is, when the product of D(Y) and D(Y+1) is zero, D(Y) or D(Y+1) is zero. Therefore, the product of D(Y-1) and D(Y) or the product of D(Y+1) and D(Y+2) is also zero. In this case, multiple peak candidates associated with the same substrate S will be found. Therefore, the above processing needs to be performed to avoid duplicate counting. The controller 66 can not only determine whether C(Y-1) is "0", but also perform similar determinations in a wider range of Y coordinates to avoid duplicate counting. Subsequently, the controller 66 determines whether Y is "maximum value - 1" (step S513). When Y is not "maximum value - 1" (step S513: "No"), the controller 66 updates the Y coordinate (step S514) and returns to step S510. When Y is "maximum value - 1" (step S514: "Yes"), the overlap determination ends.

[0129] (3) The controller 66 may denoise the third decision data before applying a first-order differential filter. More specifically, the controller 66 may apply, for example, a well-known Gaussian filter (see [link to Gaussian filter]) to the third decision data. Figure 20 This can further improve the accuracy of the above judgment.

[0130] (4) In the above embodiment, the controller 66 applies a first-order differential filter to the third decision data. However, the invention is not limited thereto. The controller 66 may apply, for example, a well-known Sobel filter to the third decision data, instead of a first-order differential filter.

[0131] (5) In the above embodiment, the controller 66 calculates the number of substrates S in the third determination region 213. However, the present invention is not limited thereto. The controller 66 can perform overlap determination by detecting the thickness of the substrates S in the third determination region 213.

[0132] (6) In the above embodiments, the controller 66 performs overlap determination by using gradient intensity or difference data and pixel value data. That is, pixel value data plays an auxiliary role in overlap determination. However, the present invention is not limited thereto. For example, the controller 66 may use only gradient intensity and / or difference data in overlap determination, without directly using pixel value data. For example, when the gradient intensity is greater than or equal to Tg, the controller 66 may determine that a substrate has been detected, and then may determine that the peak value of the pixel has been found based on the product of D(Y) and D(Y+1). For example, the controller 66 may count the number of times the substrate S is detected by combining these determinations.

[0133] Alternatively, a procedure for determining overlap using only pixel value data, without using gradient intensity data or difference data, can be stored in controller 66. Controller 66 can be programmed to select one of three modes as the overlap determination mode: The first mode uses gradient intensity data or difference data along with pixel value data. The second mode uses only gradient intensity data and / or difference data. The third mode uses only pixel value data.

[0134] (7) In the above embodiment, the controller 66 uses third determination data to perform overlap determination. However, the present invention is not limited thereto. The controller 66 may also perform overlap determination using first determination data or second determination data.

[0135] (8) In the above embodiment, the number of cameras 61 is two. However, the present invention is not limited thereto. The number of cameras 61 may be three or more. Alternatively, the number of cameras 61 may be one.

[0136] (9) The type of container is not limited to FOUP 100. The present invention can also be applied to other containers (not shown) besides FOUP 100.

[0137] (10) When viewed from above, the shape of the substrate S may be different from that of a generally rectangular shape. For example, the substrate S may be a plate-shaped generally circular plate.

[0138] (11) In the above embodiment, the scanner 45 is fixed to the door 50 (i.e., the scanner 45 is driven by the motor 58 to move together with the door 50 in the vertical direction). However, the present invention is not limited thereto. The scanner 45 may also be fixed to other components.

[0139] (12) In the above embodiment, the controller 66 causes each camera 61 to perform imaging based on the imaging plan. However, the present invention is not limited thereto. For example, the controller 66 can cause each camera 61 to perform imaging while determining the position of the scanner 45 in the vertical direction.

[0140] (13) In the above embodiments, the LP control device 46 and the controller 66 are provided separately. However, the present invention is not limited thereto. For example, the LP control device 46 may be equipped with the controller 66. Alternatively, the LP control device 46 may replace the controller 66 and have the function of controlling each camera 61. When the LP control device 46 has the above-mentioned function, the LP control device 46 is equivalent to the determiner of the present invention. Alternatively, for example, the control device 5 of EFEM 1 may control the loading port 4. In this case, the control device 5 is equivalent to the determiner of the present invention.

[0141] (14) Loading port 4 can be placed on a device other than EFEM 1.

[0142] (15) This invention can be applied to mapping devices other than loading port 4.

[0143] While certain embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. In fact, the embodiments described herein can be embodied in many other forms. Furthermore, various omissions, substitutions, and modifications can be made to the forms of the embodiments described herein without departing from the spirit of the invention. The appended claims and their equivalents are intended to cover such forms or modifications that fall within the scope and spirit of the invention.

[0144] Explanation of reference numerals in the attached figures

[0145] 4: Loading port, 62: Light emitter, 64: Second camera (imager), 66: Controller (determiner), 100: FOUP (container), 200: Imaging area, S: Substrate.

Claims

1. A mapping apparatus for detecting the containment state of a plurality of substrates, the plurality of substrates being arranged in a predetermined thickness direction and contained in a container, the mapping apparatus comprising: The light emitter is configured to emit light at least toward the interior of the container; An imager is configured to image a predetermined imaging area by sensing the reflected light emitted by the light emitter in order to acquire image information; as well as The determiner is configured to determine the accommodating state of the plurality of substrates by using the image information. The image information includes multiple pixel value information, where each pixel value represents the intensity of reflected light at a corresponding coordinate in the thickness direction. Furthermore, the determiner uses information on the change in multiple pixel values ​​that change with the coordinate change in the thickness direction to determine whether there are two or more substrates in the accommodating region of the imaging region, wherein the accommodating region is the area used to accommodate one of the multiple substrates.

2. The mapping apparatus according to claim 1, wherein, The determiner acquires numerical information representing one of the following: the number of peak values ​​of a pixel, the number of times a pixel value begins to increase, and the number of times a pixel value stops decreasing, based on the change information, and counts the number of substrates in the accommodating area based on the numerical information during the determination process.

3. The mapping apparatus according to claim 1 or 2, wherein, In the determination process, the determiner uses not only the change information but also the pixel value information.

4. A mapping method performed in a mapping apparatus for detecting the containment state of a plurality of substrates, the plurality of substrates being contained in a container while arranged in a predetermined thickness direction, the mapping method comprising: Light is emitted at least toward the interior of the container; Image information is obtained by sensing the reflected light of the light to image a predetermined imaging area. as well as The image information is used to determine the accommodating state of the plurality of substrates. The image information includes multiple pixel value information, where each pixel value represents the intensity of reflected light at a corresponding coordinate along the thickness direction. The determination process includes using information on the change in multiple pixel values ​​that change with the coordinates in the thickness direction to determine whether there are two or more substrates in the accommodating area of ​​the imaging region. The accommodating area is the area used to accommodate one of the multiple substrates.

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