Detection equipment and substrate state detection method
By using photoelectric sensors to detect the substrate status, the problem of substrate breakage or loss during carrier transfer was solved, enabling timely anomaly alerts and improving production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-03-10
AI Technical Summary
In the semiconductor manufacturing process, substrates are prone to breakage or loss during carrier transfer, leading to process abnormalities that are difficult to detect and handle in a timely manner using existing technologies.
The photoelectric sensor detection equipment is used to detect the status of the substrate on the carrier by setting the angle between the detection paths of the first and second photoelectric sensors, and output abnormal alarm information.
This improved the reliability of the substrate transfer process, reduced more serious problems caused by substrate abnormalities, and increased the production yield.
Smart Images
Figure CN121646334A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of detection equipment, in particular to a detection equipment and a substrate state detection method. BACKGROUND
[0002] In the field of semiconductors, processes such as coating or heating of substrates require the use of carriers for transfer. In order to improve production efficiency, a plurality of substrates are usually carried on the carrier. In the related art, the substrates carried on the carrier may be broken or lost during the transfer process. If the abnormality occurring during the transfer of the substrates cannot be found in time, it is easy to cause more serious problems in the process or transfer of the substrates. SUMMARY
[0003] Embodiments of the present application provide a detection equipment and a substrate state detection method thereof, which can detect the state of the substrate and improve the yield.
[0004] Embodiments of the present application provide a substrate state detection method of a detection equipment. The detection equipment includes a carrier and a photoelectric sensor. The carrier is configured to carry a substrate. The photoelectric sensor is configured to output corresponding detection information according to whether its detection path is blocked; and the carrier moves relative to the sensor along a first direction. The photoelectric sensor includes a first photoelectric sensor and a second photoelectric sensor, and the detection paths of the first photoelectric sensor and the second photoelectric sensor are arranged at an included angle, and the detection paths of the first photoelectric sensor and the second photoelectric sensor intersect.
[0005] The method includes: S10: controlling the carrier to move relative to the photoelectric sensor along a preset path; S20: obtaining detection information of the first photoelectric sensor and the second photoelectric sensor; S30: comparing the detection information of the photoelectric sensor with preset information, and determining whether the detection information is abnormal; S40: outputting alarm information in the case that the detection information is abnormal.
[0006] Optionally, the detection information includes the number of times that the detection path is blocked, the length of time that the detection path is not blocked, and the length of time that the detection path is blocked each time.
[0007] Optionally, step S30 includes: S31: comparing the total number of times that the detection path is blocked in the detection information with a preset number of times; If the total number of times that the detection path is blocked is less than or greater than the preset number of times, the alarm information is outputted.
[0008] Optionally, step S20 includes: S21: determining whether the time length of the detection path of the first photoelectric sensor and the detection path of the second photoelectric sensor being blocked at the same time is equal; If the time length of the detection path of the first photoelectric sensor and the detection path of the second photoelectric sensor being blocked at the same time is not equal, the difference between the two is calculated.
[0009] Optionally, step S30 comprises: S32: comparing the difference with a first preset difference; Step S40 comprises: S41: if the difference is greater than the first preset difference, outputting alarm information.
[0010] Optionally, the angle between the detection path of the first photoelectric sensor and the detection path of the second photoelectric sensor is 60 degrees to 135 degrees.
[0011] Optionally, when the alarm information is outputted, the method further comprises: Outputting the difference, and determining the inclination degree of the substrate according to the difference.
[0012] Optionally, step S31 comprises: S311: comparing the time length of the detection path being blocked before and / or after the missing time in the detection information with a first preset time length; S42: if the time length of the detection path being blocked before and / or after is greater than the first preset time length, outputting alarm information of the substrate being lost to the before and / or after position.
[0013] Optionally, step S30 comprises: S33: comparing the time length of the detection path not being blocked with a second preset time length; Step S40 comprises: S43: if the difference between the time length of the detection path not being blocked and the second preset time length is greater than a second preset difference, outputting alarm information that the position of the substrate is not in the preset position.
[0014] Optionally, the carrier comprises an upper plate, a lower plate, and a spacing plate arranged between the upper plate and the lower plate, and the preset number of times is the sum of the number of substrates carried by the carrier and the number of the upper plate, the lower plate, and the spacing plate.
[0015] Optionally, the first direction is perpendicular to the detection path.
[0016] This application provides a detection device. The detection device uses the substrate state detection method described above. The detection device includes a carrier, a photoelectric sensor, and a moving mechanism. The photoelectric sensor is configured to output corresponding detection information based on whether its detection path is blocked; the carrier moves relative to the sensor along a first direction, and the photoelectric sensor includes a first photoelectric sensor and a second photoelectric sensor, with the detection paths of the first photoelectric sensor and the second photoelectric sensor set at an angle. The moving mechanism is used to drive the carrier to move.
[0017] The beneficial effects of this application are as follows: Unlike existing technologies, by setting up photoelectric sensors, the detection path of the photoelectric sensors is blocked by the substrate as the carrier moves along a preset path relative to the photoelectric sensors. However, the gaps between substrates do not block the detection path of the photoelectric sensors. After the carrier moves, the photoelectric sensors can output corresponding detection information. By comparing the detection information with preset information, i.e., information indicating that the substrate is properly positioned, it can be determined whether the substrate is functioning correctly during the transfer process by the carrier. For example, in the event of a lost substrate or substrate tilting, the comparison between the detection information and the preset information can confirm the existence of the abnormality, thereby issuing an alarm and promptly handling the corresponding abnormality. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of an embodiment of the testing equipment of this application; Figure 2 This is a schematic diagram of another embodiment of the testing equipment of this application; Figure 3 This is a schematic diagram of the photoelectric sensor detecting the substrate position in this application; Figure 4 This is a schematic diagram of the waveform generated after detection by the photoelectric sensor in this application; Figure 5 This is a flowchart illustrating the substrate state detection method of this application; Figure 6 This is a schematic diagram of a specific embodiment of the substrate state detection method of this application. Detailed Implementation
[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0020] Combination Figures 1 to 3This application provides a detection device 1. The detection device 1 uses the substrate state detection method described below. The detection device 1 includes a carrier 12, a photoelectric sensor 13, and a moving mechanism 14. Optionally, the detection device 1 also includes a housing 11. The housing 11 has a reaction chamber 15. The carrier 12 is movably disposed relative to the housing 11. The photoelectric sensor 13 is mounted on the housing 11. The moving mechanism 14 is used to drive the carrier 12 into or out of the reaction chamber 15. The photoelectric sensor 13 can detect the transfer of the substrate on the carrier 12 during the process of the carrier 12 entering the reaction chamber 15. The photoelectric sensor 13 can also detect the transfer of the substrate on the carrier 12 during the process of the carrier 12 leaving the reaction chamber 15. Depending on the actual process requirements, the photoelectric sensor 13 can detect only the entry or exit of the carrier 12, or it can detect both the entry and exit processes of the carrier 12.
[0021] This application provides a substrate state detection method for a detection device 1. The detection device 1 includes a carrier 12 and a photoelectric sensor 13. The carrier 12 is used to support the substrate. The photoelectric sensor 13 is configured to output corresponding detection information based on whether its detection path is blocked. The device may also include a control component, which is used to receive the information from the photoelectric sensor 13 and perform corresponding processing and analysis. The control component can also control the movement of the carrier 12 or issue corresponding alarms, etc.
[0022] In some embodiments, the photoelectric sensor 13 may include a transmitter and a receiver, forming a detection path between them. If the receiver receives light emitted by the transmitter, it generates a corresponding electrical signal. If the detection path is blocked, the receiver will not receive light emitted by the transmitter and will still generate a corresponding electrical signal. The electrical signal may be a high level, a low level, or a zero level; no specific limitation is made here.
[0023] For example, the detection information from photoelectric sensor 13 can form Figure 4 The waveform shown indicates that a high level represents occlusion and a low level represents no occlusion. From this waveform, we can obtain the number of times occlusion occurred, the number of times occlusion did not occur, the duration of occlusion, and the duration of no occlusion. Comparing two different waveforms allows us to determine the time difference in occlusion duration for corresponding number of occurrences.
[0024] In some embodiments, the photoelectric sensor 13 can be a distance sensor, which can determine the distance to a target by emitting light and receiving reflected light. If the detection path is unobstructed, corresponding distance information will be generated. If the detection path is obstructed, the measured distance value will be smaller.
[0025] In some embodiments, the carrier 12 moves relative to the sensor along a first direction, optionally perpendicular to the detection path. Substrates are spaced apart along the first direction. In this way, during the movement of the carrier 12, the spaced-apart substrates may obstruct the detection path as they rise or fall, but the spacing between the substrates will not obstruct the detection path. During the movement of the carrier 12, the photoelectric sensor 13 can output corresponding detection information based on whether the detection path is obstructed or not. If no problems occur with the substrate during the transfer process, the detection information should be substantially consistent with the preset information, allowing the next step to proceed normally. However, if the substrate experiences problems such as loss, breakage, or tilting, the detection information output by the photoelectric sensor 13 will differ significantly from the preset information. The presence or absence of this difference determines whether a problem has occurred during the substrate transfer process. Timely issuance of alarm information in the event of a problem during substrate transfer can reduce more serious problems caused by the substrate transfer issue. For example, during the transfer of substrates by the robotic arm, problems may arise due to substrate tilting, or the substrate may be lost or broken during the coating process, leading to disruption of the process conditions.
[0026] Combination Figure 5 and Figure 6 The substrate condition detection method of detection device 1 includes: S10: Control the vehicle 12 to move relative to the photoelectric sensor 13 along a preset path.
[0027] It should be noted that the substrate transfer detection method of this application can be performed during the substrate transfer process in the equipment, or it can be a process that only detects the condition of the substrate, without the need for equipment. Optionally, the movement direction of the carrier 12 is perpendicular to the detection path.
[0028] During the transfer of the substrate by the carrier 12, it can move along a first direction. During this movement, the photoelectric sensor 13 can detect the placement state of the substrate. The preset path refers to the path along which the photoelectric sensor 13 can detect the placement state of the substrate during the transfer process. Optionally, the starting state is when the top of the carrier 12 is below the detection path, and the final state is when the bottom of the carrier 12 is above the detection path. Alternatively, the starting state is when the bottom of the carrier 12 is above the detection path, and the final state is when the top of the carrier 12 is below the detection path. The preset path can be the movement path of the carrier 12 between the aforementioned starting and final states.
[0029] In some embodiments, the photoelectric sensor 13 can detect the transfer of the substrate on the carrier 12 during the process of the carrier 12 entering the reaction chamber 15. The photoelectric sensor 13 can also detect the transfer of the substrate on the carrier 12 during the process of the carrier 12 being removed from the reaction chamber 15. Depending on the actual process requirements, the photoelectric sensor 13 can detect only the entry or exit of the carrier 12, or it can detect both the entry and exit processes of the carrier 12.
[0030] In other words, the preset path can be the path through which the vehicle 12 enters the reaction chamber 15, or the path through which the vehicle 12 moves out of the reaction chamber 15.
[0031] S20: Acquire the detection information of the first photoelectric sensor 131 and the second photoelectric sensor 132.
[0032] After the carrier 12 moves, the photoelectric sensor 13 can detect the corresponding detection information. By acquiring and analyzing the detection information from the photoelectric sensor 13, it is possible to determine whether there is any abnormality in the placement of the substrate. Furthermore, it is possible to determine the general types of abnormalities that may have occurred on the substrate.
[0033] In some embodiments, the detection information includes the number of times the detection path was occluded, the duration of the detection path not being occluded, and the duration of each instance of the detection path being occluded.
[0034] In some embodiments, the carrier 12 includes an upper plate, a lower plate, and a spacer plate disposed between the upper plate and the lower plate, and the preset number is the sum of the number of substrates carried by the carrier 12 and the number of the upper plate, the lower plate, and the spacer plate.
[0035] In some embodiments, the detection device 1 includes a first photoelectric sensor 131 and a second photoelectric sensor 132. Both the first photoelectric sensor 131 and the second photoelectric sensor 132 can output corresponding detection information based on whether their detection paths are blocked or not. By setting the first photoelectric sensor 131 and the second photoelectric sensor 132, the state information of the substrate can be obtained from different angles, thereby increasing the accuracy of the detection information and making it easier to accurately identify the state of the substrate.
[0036] Optionally, the angle between the detection path of the first photoelectric sensor 131 and the detection path of the second photoelectric sensor 132 is 60 degrees to 135 degrees, such as 85 degrees, 90 degrees, or 105 degrees. If the angle between the detection paths of the first photoelectric sensor 131 and the second photoelectric sensor 132 is too small or too large, it will increase the amount of duplicate information in the detection information acquired by the first photoelectric sensor 131 and the second photoelectric sensor 132. Increased duplicate information will reduce the amount of effective information in the detection information.
[0037] S21: Determine whether the duration of occlusion of the corresponding detection paths in the detection information of the first photoelectric sensor 131 and the detection information of the second photoelectric sensor 132 is equal during the same period. If the duration of occlusion of the corresponding detection paths in the detection information of the first photoelectric sensor 131 and the detection information of the second photoelectric sensor 132 is not equal, then calculate the difference between the two. By acquiring the detection information of the first photoelectric sensor 131 and the second photoelectric sensor 132, it is possible to determine whether there is an abnormality in the substrate placement by comparing the detection information of the first photoelectric sensor 131 and the detection information of the second photoelectric sensor 132 with preset information, and also to determine whether there is an abnormality in the substrate placement by comparing the detection information of the first photoelectric sensor 131 and the detection information of the second photoelectric sensor 132.
[0038] First, it can be determined whether the duration of occlusion of the corresponding detection paths in the detection information of the first photoelectric sensor 131 and the second photoelectric sensor 132 is equal during the same period. If they are equal, it is unnecessary to detect the difference between the two, as the substrate placement problem cannot be detected at least in terms of the occlusion duration of the first photoelectric sensor 131 and the second photoelectric sensor 132. If the duration of occlusion of the corresponding detection paths in the detection information of the first photoelectric sensor 131 and the second photoelectric sensor 132 is not equal during the same period, it indicates that the substrate placement may be tilted. The difference between the two needs to be calculated to further confirm whether there is an anomaly and the severity of the anomaly.
[0039] S30: Compare the detection information of photoelectric sensor 13 with preset information and determine whether there is any abnormality in the detection information.
[0040] The photoelectric sensor 13 obtains various types of detection information, and there are also various ways to compare the detection information with preset information. Different methods may determine different abnormal states. The present application can provide the following specific embodiments.
[0041] S31: Compare the number of times the detection path was occluded in the detection information with the preset number; The preset number of times is the number of times the detection path is obstructed when the substrate is placed normally. If the actual number of times the detection path is obstructed is less than the preset number, it indicates that the substrate has a problem of missing or broken pieces. If the number of times the detection path is obstructed is greater than the preset number, there may be a problem of the carrier 12 overloading the substrate.
[0042] Taking a carrier 12 with an upper and lower plate, carrying two substrates as an example, the upper and lower plates are part of the carrier 12's structure. If the carrier 12 does not malfunction, the upper and lower plates will inevitably obstruct the detection path. Under normal placement, the detection path will be obstructed twice for the two substrates. Therefore, the preset number of detections should be four. If the actual number of detections is greater than or less than four, it indicates a problem in the substrate placement or transfer process, requiring technical intervention.
[0043] S311: Based on the above steps, compare the duration of the detection path being occluded before and / or after the number of times the detection information is missing with the first preset duration.
[0044] The absence of a certain number of occurrences indicates a possible substrate loss or fragmentation at the corresponding location. This fragmentation or loss may be superimposed on an adjacent substrate. By comparing the duration of path occlusion before and / or after the missing occurrence with a first preset duration, it's possible to determine whether the missing or fragmented substrate is superimposed on an adjacent substrate, thus helping to identify the type of substrate anomaly.
[0045] S32: Compare the difference with the first preset difference.
[0046] The first photoelectric sensor 131 and the second photoelectric sensor 132 are installed at the same height. Their detection paths simultaneously detect the same substrate. When the substrate is not tilted, the projection range of the substrate is consistent when viewed from different directions perpendicular to the first direction, and the duration of obstruction of the detection path of the first photoelectric sensor 131 and the second photoelectric sensor 132 should be consistent. However, when the substrate is tilted, the projection of the substrate changes when viewed from different directions perpendicular to the first direction. Since the first photoelectric sensor 131 and the second photoelectric sensor 132 are set at an angle, there will be a difference in the duration of obstruction of the detection path of the first photoelectric sensor 131 and the second photoelectric sensor 132. Therefore, if there is a difference in the duration of obstruction of the detection path between the first photoelectric sensor 131 and the second photoelectric sensor 132 at the same time, it indicates that the substrate is tilted. In the case of factors such as detection accuracy and measurement error, the detection information of the first photoelectric sensor 131 and the detection information of the second photoelectric sensor 132 will have a difference in the duration of the detection path being blocked at the same time, even if there is no abnormality in the substrate. Therefore, it is necessary to compare the difference with the first preset difference to reduce false alarms caused by errors.
[0047] S33: Compare the duration during which the detection path is not occluded each time with the second preset duration; The substrates on carrier 12 should be placed at preset intervals to meet the corresponding process requirements. The detection path will not be obstructed between the substrate intervals. By comparing the duration of each unobstructed period with a second preset duration, it can be determined whether the substrate intervals meet the requirements.
[0048] Taking uniform substrate spacing as an example, the duration of unobstructed time for each detection path should be the same, and the second preset duration should also be consistent. If the duration of unobstructed time does not match the second preset duration, the substrate placement may not meet the process requirements.
[0049] It should be noted that the second preset duration corresponds to the duration during which the detection path is not obstructed in each iteration. This second preset duration may vary each time. A duration table corresponding to the intervals can be created using the second preset duration, and its consistency can be determined by comparing it with the data in the table. The reason for differences in the second preset duration may be that the spacing between the upper or lower board and the substrate differs from the spacing between the substrates. Alternatively, the manufacturing process may require variations in the spacing between the substrates.
[0050] S34: Compare the duration of each detection path being occluded in the detection information with the third preset duration.
[0051] During placement, some substrates may be transferred to carrier 12, potentially causing substrate stacking. The third preset duration represents the duration during which a substrate can obscure the detection path. By comparing the duration of each obscuring of the detection path with the third preset duration, it is possible to determine whether substrate stacking has occurred.
[0052] Optionally, the duration of the detection path being blocked can be the average duration of the blocking of the first photoelectric sensor 131 and the second photoelectric sensor 132. Since the tilt of the substrate also affects the duration of the detection path being blocked, the influence of substrate tilt on the judgment can be reduced by using the average duration of the blocking of the detection path of the first photoelectric sensor 131 and the second photoelectric sensor 132 as a comparison criterion.
[0053] S40: Output alarm information if abnormalities are detected.
[0054] If the detection information shows the above-mentioned anomalies, corresponding alarm information needs to be output. Specifically: S41: Corresponding to step S32, output alarm information. Since the difference may be caused by manufacturing errors of the photoelectric sensor 13 itself, and a certain degree of substrate tilt is allowed, by setting a first preset difference value, manufacturing errors and the allowable tilt range can be included. Once the difference value exceeds the first preset difference value, an alarm information for substrate tilt needs to be issued.
[0055] Furthermore, the degree of substrate tilt can be determined by outputting the difference. The difference itself carries information about the substrate tilt; it can be directly output as a representative of the tilt, or the difference can be processed to obtain information such as the tilt ratio, without specific limitations here.
[0056] S42: Corresponding to step S32, if the total number of times the detection path is blocked is less than or greater than the preset number, output the chip loss alarm information.
[0057] If the total number of times the detection path is blocked is less than the preset number, an alarm can be triggered indicating a potential film loss issue. If the total number of times the detection path is blocked is greater than the preset number, an alarm can be triggered indicating a potential substrate overload issue.
[0058] S421: Corresponding to step S321, if the duration of the previous and / or subsequent detection path being blocked is greater than the first preset duration, if this occurs, it means that the lost substrate or substrate fragment has fallen on the adjacent previous or next substrate, and an alarm message indicating that the substrate was lost to the previous and / or subsequent position is output.
[0059] S43: Corresponding to step S33, if the difference between the duration during which the detection path is not blocked and the second preset duration is greater than the second preset difference, it indicates that there is a difference between the interval between the substrates and the preset interval, and an alarm message indicating that the substrate position is not in the preset position is output.
[0060] S44: Corresponding to step S34, if the duration of each detection path being blocked is greater than the third preset duration, it indicates that the substrate may have a stacking problem, and an alarm will be output to indicate substrate stacking.
[0061] In summary, by setting up the photoelectric sensor 13, the detection path of the photoelectric sensor 13 is blocked by the substrate as the carrier 12 moves along a preset path relative to the photoelectric sensor 13, carrying the substrate. However, the gaps between substrates do not block the detection path of the photoelectric sensor 13. After the carrier 12 moves, the photoelectric sensor 13 can output corresponding detection information. By comparing the detection information with the preset information, i.e., the information indicating that the substrate is properly positioned, it can be determined whether the substrate is functioning normally during the transfer process by the carrier 12. For example, in the event of a substrate loss or tilting, the comparison between the detection information and the preset information can confirm the existence of the abnormality, thereby issuing an alarm and promptly handling the corresponding abnormality.
[0062] The above are merely embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A method for detecting a state of a substrate, the method comprising: a carrier configured to carry the substrate; a photoelectric sensor configured to output detection information according to whether a detection path of the photoelectric sensor is blocked, the carrier being configured to move relative to the photoelectric sensor along a first direction, the photoelectric sensor comprising a first photoelectric sensor and a second photoelectric sensor, the detection path of the first photoelectric sensor and the detection path of the second photoelectric sensor being arranged at an angle, and the detection path of the first photoelectric sensor intersecting the detection path of the second photoelectric sensor; the method comprising: S10, controlling the carrier to move relative to the photoelectric sensor along a preset path; S20, obtaining the detection information of the first photoelectric sensor and the second photoelectric sensor; S30, comparing the detection information of the photoelectric sensor with preset information, and determining whether the detection information is abnormal; and S40, outputting alarm information if the detection information is abnormal. 2.The method of claim 1, wherein the detection information comprises a number of times the detection path is blocked, a time length during which the detection path is not blocked, and a time length during which the detection path is blocked each time. 3.The method of claim 2, wherein step S30 comprises: S31, comparing a total number of times the detection path is blocked in the detection information with a preset number of times; and outputting alarm information if the total number of times the detection path is blocked is less than or greater than the preset number of times. 4.The method of claim 2, wherein step S20 comprises: S21, determining whether a time length during which the detection path is blocked at a corresponding time in the detection information of the first photoelectric sensor and the detection information of the second photoelectric sensor is equal; and calculating a difference value if the time length during which the detection path is blocked at the corresponding time in the detection information of the first photoelectric sensor and the detection information of the second photoelectric sensor is not equal. 5.The method of claim 4, wherein step S30 comprises: S32, comparing the difference value with a first preset difference value; and step S40 comprises: S41, outputting alarm information if the difference value is greater than the first preset difference value. 6.The method of claim 1, wherein an angle between the detection path of the first photoelectric sensor and the detection path of the second photoelectric sensor is 60 degrees to 135 degrees. 7.The method of claim 4, wherein simultaneously with step S40, the method further comprises: S50, outputting the difference value, and determining a degree of inclination of the substrate according to the difference value. 8.The method of claim 2, wherein step S31 comprises: S311, comparing a time length during which the detection path is blocked before and / or after a missing time in the detection information with a first preset time length; and step S40 comprises: S42, outputting alarm information of a missing substrate to a position before and / or after if the time length during which the detection path is blocked before and / or after is greater than the first preset time length. 9.The method of claim 2, wherein step S30 comprises: S33: comparing the time length of each time when the detection path is not blocked with the second preset time length; Step S40 comprises: S43: if the difference between the time length of each time when the detection path is not blocked and the second preset time length is greater than the second preset difference, outputting alarm information that the substrate position is not at the preset position.
10. The method of claim 6, wherein: The carrier comprises an upper plate, a lower plate, and a spacer plate disposed between the upper plate and the lower plate, and the preset number is the sum of the number of substrates carried by the carrier and the number of the upper plate, the lower plate, and the spacer plate.
11. The method of claim 1, wherein: The first direction is perpendicular to the detection path.
12. A detection device, characterized by The method of any one of claims 1-11 is used: The detection device comprises: A carrier, which is movably disposed; A photoelectric sensor configured to output corresponding detection information according to whether its detection path is blocked; the carrier moves relative to the sensor along a first direction, the photoelectric sensor comprises a first photoelectric sensor and a second photoelectric sensor, and the detection paths of the first photoelectric sensor and the second photoelectric sensor are arranged at an included angle; A moving mechanism for driving the carrier to move.