Method for determining rectangular substrates and mapping mechanism

Abstract

To provide a technique capable of accurately determining the housing state of a rectangular substrate in a container.SOLUTION: A determination method for a rectangular substrate B includes steps of: emitting an elliptical spot light to a side surface of the rectangular substrate B while varying positions in a vertical direction from a direction opposite to the side surface of the rectangular substrate B housed in a slot SL in a FOUP 7; and determining the housing state of the rectangular substrate B in accordance with a time when the reflection light from the side surface of the rectangular substrate B is received. According to the determination method for the rectangular substrate B, a loading abnormality in the rectangular substrate B can be determined only by emitting one spot light. Therefore, since the loading abnormality in the rectangular substrate can be determined without providing a plurality of mapping sensors, the determination method can contribute to reducing the cost of a rode port 3.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] This application relates to a technique for determining a rectangular substrate housed in a container.

Background Art

[0002] Patent Document 1 describes a load port having a mapping function for recognizing a semiconductor wafer housed in a container transported to the load port. Specifically, this load port includes a light projecting unit and a light receiving unit on the left and right, and has a mapping sensor composed of a transmissive optical sensor with an optical axis, which is the irradiation axis of the detection wave, directed in the horizontal direction to the left and right. The mapping sensor is moved from above downward to recognize the housing state of the semiconductor wafer housed in the shelves of containers such as FOUP (Front-Opening Unified Pod) and open cassette, for example, the thickness of the semiconductor wafer and abnormal loading.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, Panel Level Packaging (PLP), which manufactures packages in a single unit using larger rectangular substrates than semiconductor wafers, has attracted attention. In PLP, however, it is necessary to recognize the state in which the large rectangular substrate is housed in the container. One possibility for recognizing the state in which the rectangular substrate is housed is to use a transmissive mapping sensor, as described in Patent Document 1. However, when using a transmissive mapping sensor to recognize the state in which the rectangular substrate is housed, it is necessary to bring the mapping sensor close to the rectangular substrate so that a part of the rectangular substrate is positioned between the light-emitting and light-receiving parts. However, with large rectangular substrates, there is not enough space between the outer edge of the substrate and the peripheral wall of the container to insert the mapping sensor (see Figure 3 below), making it difficult to recognize the state in which the rectangular substrate is housed using a transmissive mapping sensor.

[0005] In response to this, it is conceivable to use a reflective mapping sensor instead of a transmissive mapping sensor. However, conventional reflective mapping sensors emit a circular spot of light, which means that, for example, even if rectangular substrates are stored at different levels on the shelves of a container, they may be mistakenly identified as being properly stored on the same shelf.

[0006] The present invention aims to provide a technology that enables accurate determination of the state in which a rectangular substrate is housed within a container. [Means for solving the problem]

[0007] To achieve the above objective, the method for determining a rectangular substrate according to the present invention is characterized by irradiating the side surface of a rectangular substrate housed in a slot in a container with detection light having a shape with different lengths in two mutually perpendicular axes, while varying the position in the direction perpendicular to the side surface of the rectangular substrate, and determining the state of housing the rectangular substrate according to the time for which reflected light from the side surface of the rectangular substrate is received.

[0008] This allows the placement status of a rectangular substrate to be determined by irradiating it with a single detection light. Therefore, since the placement status of a rectangular substrate can be determined without installing multiple mapping sensors, it is possible to contribute to cost reduction.

[0009] Furthermore, the reflectance of the reflected light may also be taken into consideration when determining the housing state of the rectangular substrate.

[0010] This makes it possible to further expand the range of types of housing conditions for rectangular substrates and determine them accordingly.

[0011] Furthermore, the length of the long axis of the detected light may be set to be at least 1 / 10 of the length of the longitudinal side of the rectangular substrate.

[0012] This makes it possible to improve the accuracy of determining the housing status of rectangular substrates.

[0013] Furthermore, if the reflectance of the reflected light is below a predetermined reflectance threshold, it may be determined that the rectangular substrate is stored in the slot in an uneven manner.

[0014] This makes it possible to further expand the types of housing configurations for rectangular substrates while improving the accuracy of their determination.

[0015] Furthermore, if the reflectance of the reflected light exceeds a predetermined reflectance threshold and the time for which the reflected light was received exceeds a predetermined time threshold, it may be determined that multiple rectangular substrates are being housed in a stacked state.

[0016] This makes it possible to further expand the types of housing configurations for rectangular substrates while improving the accuracy of their determination.

[0017] To achieve the above object, the mapping mechanism of the present application includes a mapping sensor that irradiates detection light with different shapes in two axial directions perpendicular to each other on the side surface of a rectangular substrate while varying the vertical position from a direction facing the side surface of the rectangular substrate accommodated in a container that accommodates a plurality of substrates in multiple stages, and a controller that determines the accommodation state of the rectangular substrate according to the time when the mapping sensor receives the reflected light from the side surface of the rectangular substrate. It is characterized by this.

[0018] Thereby, the accommodation state of the rectangular substrate can be determined by irradiating only one detection light. Therefore, the accommodation state of the rectangular substrate can be determined without providing a plurality of mapping sensors, which makes it possible to contribute to reducing the manufacturing cost of the mapping mechanism.

Brief Description of the Drawings

[0019] [Figure 1] It is a side sectional view of a load port according to an embodiment of the present application. [Figure 2] It is a side sectional view showing a state where the door part is moved downward together with the lid part of the FOUP from the state of FIG. 1. [Figure 3] It is a diagram showing an example of the positional relationship between the mapping sensor in FIG. 1 and the rectangular substrate to be determined. [Figure 4] It is a block diagram showing the control configuration of the load port of FIG. 1. [Figure 5] It is a flowchart showing the procedure of the substrate accommodation state determination process executed by the controller in FIG. 4, particularly the CPU. [Figure 6] It is a schematic diagram showing a state where the substrate accommodation state determination process of FIG. 5 is being executed. [Figure 7] [[ID=3…]]It is a diagram showing an example of attaching the mapping sensor to a robot arm.

Modes for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present application will be described in detail based on the drawings.

[0021] FIG. 1 shows a side cross-section of a load port 3 (an example of a "mapping mechanism") according to an embodiment of the present application. The load port 3 is assembled and used in a semiconductor manufacturing apparatus (not shown) that performs various processes on a substrate (in this embodiment, a rectangular substrate), and serves as an interface portion between a FOUP 7 that houses a plurality of substrates and the semiconductor manufacturing apparatus. In each figure, when referring to directions, the directions of the arrows shown in each figure are used.

[0022] The load port 3 has a panel 31 standing substantially vertically from behind a leg portion 35 to which a caster and an installation leg are attached, and a horizontal base portion 33 provided forward from a position about 60% of the height of this panel 31. And, on the upper part of this horizontal base portion 33, a mounting table 34 for mounting the FOUP 7 is provided.

[0023] The FOUP 7 is composed of a main body 71 having an internal space Sf for housing a substrate and a lid portion 72 that can close an opening 71a provided on one surface of the main body 71 as an access opening for the substrate. When correctly mounted on the mounting table 34, the lid portion 72 faces the panel 31. The mounting table 34 can move in the front-rear direction in a state where the FOUP 7 is mounted.

[0024] The load port 3 includes an opening / closing mechanism 6 for opening and closing an opening 42. The opening / closing mechanism 6 includes a door portion 61 for opening and closing the opening 42, a support frame 63 for supporting this, a movable block 65 that supports the support frame 63 so as to be movable in the front-rear direction via slide support means 64, and a slide rail 66 that supports the movable block 65 so as to be movable in the vertical direction with respect to the panel main body 31b. The support frame 63 supports the lower rear portion of the door portion 61, extends downward, and then has a substantially crank-shaped shape that projects forward of the panel main body 31b through a slit-shaped insertion hole 31d provided in the panel main body 31b. And, the slide support means 64, the movable block 65, and the slide rail 66 for supporting this support frame 63 are provided in front of the panel main body 31b.

[0025] Furthermore, actuators 5 (see Figure 4) are provided for each direction to move the door section 61 in the forward / backward direction and in the up / down direction. By providing drive commands from the controller 11 to these actuators, the door section 61 can be moved in both the forward / backward and up / down directions.

[0026] The door section 61 is equipped with a latch mechanism for opening and closing the lid section 72 of the FOUP 7, and a connecting mechanism (not shown) for holding the lid section 72. This connecting mechanism allows the lid section 72 to be opened by latching it, and also allows the lid section 72 to be connected to the door section 61 to form an integrated unit. Conversely, it is also possible to release the connection between the lid section 72 and the door section 61 and attach the lid section 72 to the main body 71 to form a closed state.

[0027] Furthermore, by operating the connecting mechanism, the lid 72 can be detached from the main body 71 while maintaining the connection between the lid 72 and the door 61, and the door 61 holds the lid 72 integrally. From this state, the door 61 is moved backward together with the support frame 63. In this way, the lid 72 of the FOUP 7 can be separated from the main body 71, opening the internal space Sf.

[0028] Then, as shown in Figure 2, the door portion 61 is moved downward together with the support frame 63. This allows the rear of the opening 71a, which serves as the loading / unloading entrance for the FOUP 7, to be opened wide, making it possible to move substrates between the FOUP 7 and the semiconductor manufacturing equipment. The above describes the operation when opening the opening 71a of the FOUP 7, but when closing the opening 71a of the FOUP 7, the reverse operation of the above should be performed.

[0029] As shown in Figure 3, a mapping sensor 20 is integrally fixed to the upper edge of the door portion 61. Specifically, the mapping sensor 20 is fixed to the center of the upper edge of the door portion 61 by, for example, a known fastening means (not shown). Therefore, as shown in Figure 1, when the door portion 61 is in the closed position of the opening 42, that is, when the opening 71a of the FOUP 7 is in the closed position, the mapping sensor 20 is positioned above the uppermost substrate among the multiple substrates housed in the FOUP 7.

[0030] In this embodiment, the mapping sensor 20 consists of a CMOS laser sensor that irradiates an object (in this embodiment, the substrate B shown in Figure 3 or Figure 6) with an elliptical spot laser beam SP (see Figure 6), receives the reflected light, and outputs an electrical signal corresponding to the amount of light of the received reflected light. The mapping sensor 20 is activated by the controller 11 when the door section 61 moves horizontally toward the rear and then downward.

[0031] Figure 4 shows the control configuration of the load port 3. The load port 3 includes a control device 10, which comprises a controller 11 and a motor driver 12. The controller 11 is connected to the motor driver 12, and the motor driver 12 is connected to the electromagnetic motor 51 that constitutes the actuator 5. The controller 11 is also connected to the mapping sensor 20.

[0032] The controller 11 has a CPU 11A and a memory 11B. The memory 11B includes, for example, RAM, ROM, and flash memory, and stores information related to control and processing. The memory 11B also stores control programs that execute various control processes, including the board accommodation state determination process (see Figure 5) which will be described later. The CPU 11A performs various controls on the load port 3 by executing the various control programs stored in the memory 11B.

[0033] The controller 11 controls the electromagnetic motor 51 via the motor driver 12 during the process of performing various controls on the load port 3. In this embodiment, the electromagnetic motor 51 is used as a power source when the actuator 5 moves the door section 61 vertically. If, for example, a stepping motor is used as the electromagnetic motor 51, the controller 11 supplies a pulse signal to the motor driver 12. The motor driver 12 controls the rotation axis of the stepping motor so that the rotation angle corresponds to the number of pulses in the input pulse signal. Therefore, the controller 11 can indirectly determine the current vertical position of the door section 61 by accumulating the number of pulses in the pulse signal supplied to the motor driver 12 (including the accumulation of negative values). As a result, the controller 11 can also determine the current position of the mapping sensor 20, making it possible to perform mapping by the mapping sensor 20 at any position from when the door section 61 moves the opening 42 from the fully closed state to the fully open state.

[0034] The output signal from the mapping sensor 20 (in this embodiment, it is digital data, so hereinafter referred to as "output data") is transmitted from the mapping sensor 20 to the controller 11. The controller 11 temporarily stores the output data received from the mapping sensor 20 in the memory 11B. Then, the controller 11 determines the housing status of each board B housed in each slot SL based on the output data stored in the memory 11B.

[0035] The control processing performed by the load port 3 configured as described above will be explained in detail with reference to Figures 5 and 6. Figure 5 shows the procedure for determining the substrate's storage state, which is performed by the controller 11, particularly the CPU 11A. The substrate storage state determination process is started at a predetermined timing, such as before the transport of the substrate from the FOUP 7 begins, for example, at the timing when the door 61 of the load port 3 moves up and down to open the lid 72 of the FOUP 7. When the substrate storage state determination process is started, the CPU 11A starts operating the mapping sensor 20. Hereafter, in the explanation of each process procedure, steps will be denoted as "S".

[0036] In Figure 5, the CPU 11A first sets a counter m, which counts the number of boards housed in the FOUP7 one by one from the top, to an initial value of "1" (S10).

[0037] Next, the CPU 11A calculates the reflectance of the reflected light based on the output data from the mapping sensor 20 and determines whether the calculated reflectance exceeds a predetermined threshold R1 (S12). Here, in this embodiment, the reflectance is calculated by the CPU 11A based on the output data from the mapping sensor 20, but it is not limited to this, and the mapping sensor 20 may output the reflectance as output data. The threshold R1 is "R1" shown in Figure 6, and this threshold R1 is a reference value for determining whether the mapping sensor 20 has received appropriate reflected light from the substrate B after removing noise contained in the output data.

[0038] In the determination in S12 above, if reflectance > threshold R1 (S12: YES), the CPU 11A starts timing using a timer (S14). If the controller 11 has a timer function, that can be used; if it does not have a timer function, a software timer can be built on memory 11B and used.

[0039] Next, CPU 11A determines whether the reflectance exceeds the maximum value (S16). Here, the maximum value is the value stored in memory 11B as the current maximum reflectance value. In the determination in S16, if reflectance > maximum value (S16: YES), CPU 11A updates the maximum value with the reflectance (S18) and then proceeds to S20. On the other hand, if reflectance ≤ maximum value (S18: NO), CPU 11A skips S18 and proceeds to S20.

[0040] In S20, it is determined whether the reflectance has fallen below the threshold R1. If the reflectance is greater than or equal to the threshold R1 (S20: NO), the CPU 11A returns to processing S16. The CPU 11A then repeats processing S16 to S20 until the reflectance is less than the threshold R1. Therefore, once the reflectance exceeds the threshold R1, the highest reflectance value up to the point where the reflectance falls below the threshold R1 is stored in memory 11B.

[0041] Figure 6 shows the change in reflectance calculated based on the output data from the mapping sensor 20 as it maps substrate B from outside the range of substrate B, through substrate B, and back to outside the range of substrate B from top to bottom. In Figure 6, the vertical axis represents time, and the horizontal axis represents reflectance. Assuming that the change in reflectance shown in Figure 6(a) is obtained from the mapping sensor 20 as it moves, the peak value of the reflectance is detected as the highest value of the reflectance.

[0042] Returning to Figure 5, in the judgment of S20 above, if reflectance < threshold R1 (S20: YES), the CPU 11A stops the timer (S22). For example, if the reflectance changes shown in Figures 6(a) to 6(d) are obtained, the timer timing times will be t1 to t4, respectively.

[0043] Next, the CPU 11A determines the state of the board B housed in the m-th slot SL based on the timer's timing and the maximum reflectivity (S24), and then increments the counter m's count value by "1" (S26).

[0044] In the determination of S24, first, the CPU 11A determines whether the maximum value of the reflectance exceeds a predetermined threshold value R2. This threshold value R2 is a reference value for determining whether one substrate B is correctly stored in the slot SL (the state shown in FIG. 6(a)), or two substrates B1 and B2 are stored in the slot SL in an overlapping manner (the state shown in FIG. 6(d)), that is, in a double state, and whether one substrate B is stored in a slot SL and the slot SL one step above or one step below it in a staggered manner (the state shown in FIG. 6(b)), or whether one substrate B is stored in a slot SL and the slot SL two steps above or two steps below it in a staggered manner (the state shown in FIG. 6(c)). That is, when the maximum value of the reflectance > the threshold value R2, the CPU 11A determines that the storage state of the substrate is the state shown in FIG. 6(a) or the state shown in FIG. 6(d). Then, the CPU 11A determines whether the storage state of the substrate is either of the states in FIGS. 6(a) and 6(d) based on the magnitude of the timing time of the timer. Specifically, a threshold value T1 of a predetermined time (t1 ≦ T1 < t4) is set in advance. When the timing time of the timer > the threshold value T1, the CPU 11A determines that the storage state of the substrate is in a double state. On the other hand, when the timing time of the timer ≦ the threshold value T1, the CPU 11A determines that the substrate is correctly stored.

[0045] On the other hand, when the maximum value of the reflectance ≤ threshold value R2, the CPU 11A determines that the accommodation state of the substrate is the state shown in FIG. 6(b) or the state shown in FIG. 6(c). Then, the CPU 11A determines whether the accommodation state of the substrate is either the state shown in FIG. 6(b) or FIG. 6(c) based on the magnitude of the counting time of the timer. Specifically, a threshold value T2 of a predetermined time (t2 ≤ T2 < t3) is set in advance. When the counting time of the timer > threshold value T2, the CPU 11A determines that the accommodation state of the substrate is the state shown in FIG. 6(c). On the other hand, when the counting time of the timer ≤ threshold value T2, the CPU 11A determines that the accommodation state of the substrate is the state shown in FIG. 6(b). In the present embodiment, when the accommodation state of the substrate is any of the states shown in FIGS. 6(b) to 6(d), it is called a loading abnormality. When a loading abnormality is determined, the CPU 11A associates the type of the loading abnormality, that is, which of the states shown in FIGS. 6(b) to 6(d), with the number of stages of the slot SL in which the substrate is accommodated, that is, the value of the counter m, and stores it in, for example, the memory 11B.

[0046] Returning to FIG. 5, next, the CPU 11A determines whether the determination of the accommodation state for all the substrates accommodated in the FOUP 7 has been completed (S28). Since the number of stages of the substrates that can be accommodated in the FOUP 7 is known, the determination in S28 is easy by comparing the value of the counter m with the number of stages. In this determination, if there are still substrates to be determined (S28: NO), the CPU 11A returns the process to the above S12 and repeats the processes after S12.

[0047] On the other hand, in the judgment in S12 above, if the reflectance ≤ threshold R1 (S12: NO), the CPU 11A repeats the judgment process in S12 until the mapping sensor 20 reaches the next stage slot SL (S30: NO). If the reflectance becomes > threshold R1 during this time (S12: YES), the CPU 11A proceeds to the process in S14 above. On the other hand, if the reflectance ≤ threshold R1 (S12: NO) and the mapping sensor 20 reaches the next stage slot SL (S30: YES), the CPU 11A determines that there is no substrate in the m-th stage slot SL (S32), advances the count value of counter m by "1" (S34), and then proceeds to the process in S28 above.

[0048] On the other hand, if the determination of the storage status of all boards is completed in the judgment of S28 (S28:YES), the CPU 11A determines whether or not a storage abnormality has been determined, that is, whether or not there is at least one board that has been determined to be a storage abnormality (S40). As described above, boards that have been determined to be a storage abnormality in S24 are stored in memory 11B in association with the number of stages in which the board is stored and the type of storage abnormality, so the CPU 11A can determine whether or not a storage abnormality has been determined by reading the storage area of ​​memory 11B. If a storage abnormality is determined in this judgment (S40:YES), the CPU 11A identifies which slot SL the board that has been determined to be a storage abnormality is stored in and the type of storage abnormality, and notifies the system (S42), and then terminates the board storage status determination process. As for the method of notification, for example, displaying it on a display or notifying it by sound can be considered, but any method may be adopted.

[0049] On the other hand, if no loading abnormality is detected in the judgment of S40 (S40:NO), the CPU 11A terminates the board's storage status determination process.

[0050] In this way, the substrate housing state determination process can determine whether the substrate is in the state shown in Figure 6(b) or Figure 6(c), that is, the difference in the degree of inclination of the substrate. This determination is possible because the mapping sensor 20 has an elliptical spot SP of illumination light. If a conventional illumination light with a circular spot is shone onto the substrate, it is difficult because no clear difference will be produced in the reflected light. It is preferable that the length of the major axis of the ellipse that is shone onto the substrate as illumination light is 1 / 10 or more of the length of the longitudinal side of the rectangular substrate B being illuminated. If it is less than this, the accuracy of determining the difference in the degree of inclination of the substrate will decrease. However, in this case, if multiple mapping sensors are provided, the decrease in the accuracy of each individual determination can be compensated for.

[0051] Furthermore, a method for determining differences in the degree of inclination of a substrate may be applied to determining the degree of deflection of a substrate.

[0052] As described above, the method for determining the rectangular substrate B in this embodiment involves irradiating the side surface of the rectangular substrate B, which is housed in a slot SL within the FOUP7, with an elliptical spot light SP while varying its position perpendicular to the direction facing the side surface of the rectangular substrate B, and determining the housing state of the rectangular substrate B according to the time it takes to receive the reflected light from the side surface of the rectangular substrate B. Incidentally, in this embodiment, FOUP7 is an example of a "container". The elliptical spot light is an example of a "detection light with a shape of different lengths in two mutually perpendicular axes". An abnormal loading is an example of a "housing state".

[0053] According to the method for determining the rectangular substrate B of this embodiment, a loading abnormality of the rectangular substrate B can be determined by irradiating it with a single spot light SP. Therefore, since a loading abnormality of the rectangular substrate can be determined without providing multiple mapping sensors, it is possible to contribute to reducing the cost of the load port 3.

[0054] Furthermore, the reflectance of the reflected light may also be taken into consideration when determining the stacking abnormality of the rectangular substrate B. This makes it possible to further expand the types of stacking abnormalities of the rectangular substrate B that can be determined.

[0055] Furthermore, the length of the major axis of the ellipse of the spot light SP may be set to be at least 1 / 10 of the length of the longitudinal side of the rectangular substrate. This makes it possible to improve the accuracy of detecting loading abnormalities on the rectangular substrate B.

[0056] Furthermore, if the reflectance of the reflected light is less than or equal to a predetermined reflectance threshold R1, it may be determined that the rectangular substrate B is stored in slot SL in an uneven manner. This makes it possible to further expand the types of abnormal stacking of the rectangular substrate B while improving the accuracy of the determination.

[0057] Furthermore, if the reflectance of the reflected light exceeds a predetermined reflectance threshold R1 and the time the reflected light was received exceeds a predetermined time threshold T1, it may be determined that multiple rectangular substrates are stacked together. This makes it possible to further expand the types of arrangements of rectangular substrates while improving the accuracy of the determination.

[0058] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0059] (1) In the above embodiment, FOUP7 was used as the container for housing the substrate B, but other containers such as FOSB (Front Opening Shipping Box) or non-sealed cassettes may also be used.

[0060] (2) In the above embodiment, a stepping motor was used as an example for the electromagnetic motor 51, but it is not limited to this, and a servo motor may also be used. In this case, the current vertical position of the door 61 can be indirectly determined based on the information obtained from the encoder. Alternatively, if a sensor or the like is provided to directly detect the current vertical position of the door 61, the current position of the mapping sensor 20 may be calculated based on the output from that sensor.

[0061] (3) In the above embodiment, the mapping sensor 20 was moved from top to bottom to map the substrate B, but the mapping order is not limited to this, and the sensor may be moved from bottom to top to map, or the order may be set arbitrarily by the operator.

[0062] (4) In the above embodiment, the mapping sensor 20 is fixed integrally with the door portion 61, but the invention is not limited to this, and the mapping sensor 20 may be attached to a device dedicated to mapping.

[0063] (5) In the above embodiment, the mapping sensor 20 was installed on the door 61, but the embodiment is not limited to this, and for example, as shown in Figure 7, the mapping sensor 20 may be attached to the robot 100 that transports the substrate B.

[0064] (6) In the above embodiment, the light source of the mapping sensor 20 is assumed to be one point, but it is not limited to this, and detection light with different lengths in two mutually orthogonal axes may be configured using multiple light sources.

[0065] (7) In the above embodiment, the shape of the light source of the mapping sensor 20 is elliptical, but it is not limited to this, and a rectangular, wide light source may also be used. [Explanation of Symbols]

[0066] 3...Load port, 5...Actuator, 6...Opening / closing mechanism, 7...FOUP, 10...Control device, 11...Controller, 11A...CPU, 11B...Memory, 12...Motor driver, 20...Mapping sensor, 51...Electromagnetic motor, 61...Door section, 72...Lid section, B...Circuit board, SL...Slot.

Claims

1. The method involves irradiating the side surface of a rectangular substrate housed in a slot within a container with detection light that has a shape in which the lengths in two mutually orthogonal axes are different, and the length in the longitudinal direction of one of the two axes, the side surface of the rectangular substrate, is longer than the length in the vertical direction, the other of the two axes, while varying the position in the vertical direction from the direction opposite to the side surface of the rectangular substrate housed in the slot within the container, and determining the housing state of the rectangular substrate according to the time for which reflected light from the side surface of the rectangular substrate is received. A method for identifying rectangular circuit boards.

2. The state of housing the rectangular substrate is determined by also taking into account the reflectance of the reflected light, If the reflectance of the reflected light is below a predetermined reflectance threshold, it is determined that the rectangular substrate is stored in the slot in an uneven manner. A method for determining a rectangular substrate according to claim 1.

3. The length of the major axis of the detected light is 1 / 10 or more of the length of the side surface of the rectangular substrate in the longitudinal direction. A method for determining a rectangular substrate according to claim 1.

4. If the reflectance of the reflected light exceeds the predetermined reflectance threshold and the time during which the reflected light was received exceeds the predetermined time threshold, it is determined that the rectangular substrates are housed in a stacked state. The method for determining a rectangular substrate according to claim 2.

5. A mapping sensor that irradiates detection light onto the side surface of a rectangular substrate housed in a container that houses multiple substrates in multiple stages, while varying its position vertically from a direction opposite to the side surface of the rectangular substrate, the detection light having a shape in which the length in the longitudinal direction of the side surface of the rectangular substrate, which is one of the two axial directions, is longer than the length in the vertical direction, which is the other of the two axial directions, and while varying its position vertically from a direction opposite to the side surface of the rectangular substrate, A controller that determines the housing state of the rectangular substrate according to the time it takes for the mapping sensor to receive reflected light from the side of the rectangular substrate, A mapping mechanism equipped with the following features.

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