Object placement state detection system, detection method and detection device

Abstract

The invention discloses a detection system, a detection method and a detection device for an object placement state. The detection system comprises a test object, a three-axis acceleration sensor and a controller. The three-axis acceleration sensor is arranged on the test object and detects three-axis acceleration of the test object, and the three-axis acceleration comprises X-axis acceleration, Y-axis acceleration and Z-axis acceleration; the controller calculates the current inclination angle of the test object according to the three-axis acceleration, calculates the angle difference between the current inclination angle and the reference inclination angle of the test object and judges whether the angle difference is larger than an angle threshold value or not; when the controller judges that the angle difference is larger than an angle threshold value, the controller sends out an alarm signal. According to the object placement state detection system, the detection method and the detection device provided by the invention, as long as the placement state of the tested object is monitored to be abnormal, the alarm signal is automatically sent to the detection personnel, so that the detection personnel can eliminate the abnormal condition as soon as possible, the detection time is saved, and the probability of missing detection and error detection is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of object transportation, and in particular, to a system, method and device for detecting the placement state of an object during the transportation of the object. BACKGROUND

[0002] During the manufacturing process of a wafer, the wafer must be frequently taken out from or put into a wafer slot of a wafer box by a robot. No matter the wafer is taken out from or put into the wafer slot, the relative angle between the wafer and the wafer slot or the bearing plate of the robot cannot be excessively inclined, otherwise the wafer can be scratched or even broken during the transportation of the wafer by the robot, and the broken wafer pieces will contaminate other wafers placed in the wafer box.

[0003] Currently, the detection of the wafer is performed by a detection personnel visually checking whether the wafer placed in the wafer box is excessively inclined and whether there are wafer pieces or stacked wafers. However, the manual detection is time-consuming and prone to missed detection and false detection.

[0004] Therefore, there is a need to provide a detection system, method and device for detecting the placement state of an object to solve the above problems. SUMMARY

[0005] The present application aims to solve the technical problems of the prior art by providing a detection system, method and device for detecting the placement state of an object.

[0006] To solve the above technical problems, one of the technical solutions adopted by the present application is to provide a detection system for detecting the placement state of an object, which comprises a test object, a three-axis acceleration sensor and a controller. The three-axis acceleration sensor is arranged on the test object and detects the three-axis acceleration of the test object, including X-axis acceleration, Y-axis acceleration and Z-axis acceleration. The controller calculates the current inclination angle of the test object according to the three-axis acceleration. The controller calculates the angle difference between the current inclination angle and the reference inclination angle of the test object and determines whether the angle difference is greater than an angle threshold. When the controller determines that the angle difference is greater than the angle threshold, the controller sends an alarm signal.

[0007] To solve the above technical problems, another technical solution of the present application provides a detection method for a placement state of an object. The detection method comprises the following steps: providing a test object, and a three-axis acceleration sensor is arranged on the test object; detecting three-axis acceleration of the test object by the three-axis acceleration sensor, the three-axis acceleration comprising X-axis acceleration, Y-axis acceleration and Z-axis acceleration; calculating a current inclination angle of the test object according to the three-axis acceleration by a controller; calculating an angle difference between the current inclination angle and a reference inclination angle of the test object by the controller; judging whether the angle difference is greater than an angle threshold value by the controller; and sending an alarm signal by the controller when the angle difference is greater than the angle threshold value.

[0008] To solve the above technical problems, another technical solution of the present application provides a detection method for a placement state of an object. The detection method comprises the following steps: providing a test object, and a three-axis acceleration sensor is arranged on the test object; detecting three-axis acceleration of the test object by the three-axis acceleration sensor, the three-axis acceleration comprising X-axis acceleration, Y-axis acceleration and Z-axis acceleration; calculating a current inclination angle of the test object according to the three-axis acceleration by a controller; calculating an angle difference between the current inclination angle and a reference inclination angle of the test object by the controller; judging whether the angle difference is greater than an angle threshold value by the controller; and sending an alarm signal by the controller when the angle difference is greater than the angle threshold value.

[0009] One of the beneficial effects of the present application is that the detection system, the detection method and the detection device for the placement state of the object provided by the present application can automatically send an alarm signal to the detection personnel as soon as the placement state of the test object is found to be abnormal, so that the detection personnel can quickly eliminate the abnormal condition. In this way, the detection time is saved and the probability of missed detection and wrong detection is reduced.

[0010] For a further understanding of the features and technical contents of the present application, please refer to the following detailed description of the present application and the accompanying drawings. However, the accompanying drawings provided are only for reference and illustration, and are not intended to limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 A schematic diagram of an embodiment of the detection device for the placement state of the object of the present application.

[0012] Figure 2 A schematic diagram of an embodiment of the detection system for the placement state of the object of the present application.

[0013] Figure 3 A schematic diagram of an embodiment of the detection system for the placement state of the object of the present application applied to a semiconductor process.

[0014] Figure 4 A schematic diagram of an embodiment of setting a reference position of a test wafer.

[0015] Figure 5 Flow chart of calibration procedure for wafer to be tested.

[0016] Figure 6 Schematic diagram of first embodiment of object placement status detection method of the present application.

[0017] Figure 7 Schematic diagram of second embodiment of object placement status detection method of the present application.

[0018] Figure 8 Schematic diagram of third embodiment of object placement status detection method of the present application.

[0019] Explanation of main component symbols:

[0020] 1 test object

[0021] 2 three-axis acceleration sensor

[0022] 21 ground layer

[0023] 22 light-transmitting material layer

[0024] 23 conductive layer

[0025] 24 sensing substrate

[0026] 25 first antenna

[0027] 3 second antenna

[0028] 4 radio frequency reader

[0029] 5 controller

[0030] 6 clean room

[0031] 61 first load-unload unit

[0032] 62 second load-unload unit

[0033] 63 first wafer box

[0034] 64 second wafer box

[0035] 65 robot arm

[0036] S501-S503, S601-S606, S701-S703, S801-S804 steps DETAILED DESCRIPTION

[0037] The following embodiments of the disclosed "object placement state detection system, detection method and detection device" are described in detail by specific embodiments. Those skilled in the art can understand the advantages and effects of the present application from the disclosed content of the specification. The present application can be implemented or applied by other different embodiments, and the details in the specification can be modified and changed based on different views and applications without departing from the concept of the present application. In addition, the drawings of the present application are only simple schematic illustrations, not actual size depictions, and the foregoing is declared. The following embodiments will further illustrate the related technical content of the present application, but the disclosed content is not intended to limit the protection scope of the present application.

[0038] It should be understood that although the terms "first", "second", "third" and the like can be used herein to describe various elements or signals, these elements or signals should not be limited by these terms. These terms are mainly used to distinguish one element from another element, or one signal from another signal. In addition, the term "or" used herein can include any combination of one or more associated listed items.

[0039] Figure 1 The schematic diagram of an embodiment of the object placement state detection device of the present application. Referring to Figure 1 , the detection device includes a test object 1 and a three-axis acceleration sensor 2. The test object 1 is a substitute for various products to be processed, such as circuit boards, wafers, electronic components, or mechanical components, etc. The purpose of the test object 1 is to simulate the situation that the product to be processed will encounter in the processing procedure in advance. The three-axis acceleration sensor 2 is arranged on the test object 1 to detect the three-axis acceleration of the test object 1.

[0040] The three-axis acceleration sensor 2 includes a ground layer 21, a light-transmitting material layer 22, a conductive layer 23, a sensing substrate 24, and a first antenna 25. The bottom of the ground layer 21 is connected to the test object 1 to be tested. The light-transmitting material layer 22 is, for example, Poly Methyl Methacrylate (PMMA) or Polycarbonate (PC), and the bottom of the light-transmitting material layer 22 is connected to the top of the ground layer 21. The conductive layer 23 is, for example, Aluminum Matrix Composite (AMC), and the bottom of the conductive layer 23 is connected to the top of the light-transmitting material layer 22.

[0041] The ground layer 21, the light-transmitting material layer 22, and the conductive layer 23 form a stacked structure, and the stacked structure is provided with a slot 26 that penetrates the ground layer 21, the light-transmitting material layer 22, and the conductive layer 23. The sensing substrate 24 includes a printed circuit board and an acceleration sensing wafer disposed on the printed circuit board, and the sensing substrate 24 is disposed in the slot 26. The first antenna 25 is disposed on the conductive layer 23 and connected to the sensing substrate 24.

[0042] When the test object 1 is located at the reference position at a first time point, the three-axis acceleration detected by the three-axis acceleration sensor 2 is defined as the reference three-axis acceleration of the test object 1. After the first time point, the three-axis acceleration detected by the three-axis acceleration sensor 2 is defined as the current three-axis acceleration of the test object 1. For example, a product to be processed sequentially passes through a plurality of different processing stations when the processing program is performed, and when the test object 1 is located at a first processing station, the first processing station is defined as the reference position of the test object 1.

[0043] For example, the test object 1 is a test wafer, and the test wafer is used to simulate the actual situation of the wafer in the wafer factory in advance, so that the detection personnel can adjust the parameter settings of various semiconductor machines in the wafer factory in advance to ensure the safety of the wafer during transportation or processing. When the test wafer is placed in the lowest wafer slot in the wafer box, the lowest wafer slot in the wafer box is defined as the reference position of the test wafer.

[0044] Figure 2 A schematic diagram of an embodiment of the object placement state detection system of the present application. Referring to Figure 2 , the detection system includes a test object 1, a three-axis acceleration sensor 2, a second antenna 3, a radio frequency reader 4, and a controller 5. The three-axis acceleration sensor 2 is disposed on the test object 1 to detect the three-axis acceleration of the test object 1, and the three-axis acceleration includes X-axis acceleration, Y-axis acceleration, and Z-axis acceleration.

[0045] The three-axis acceleration sensor 2 includes a ground layer 21, a light-transmitting material layer 22, a conductive layer 23, a sensing substrate 24, and a first antenna 25, and the first antenna 25 transmits radio frequency signals to the second antenna 3 or receives radio frequency signals from the second antenna 3. The second antenna 3 transmits radio frequency signals to the first antenna 25 or receives radio frequency signals from the first antenna 3. The radio frequency reader 4 is electrically connected to the second antenna 3 and the controller 5. When the first antenna 25 transmits radio frequency signals to the second antenna 3, the radio frequency signals contain information about the three-axis acceleration of the test object 1. When the second antenna 3 receives radio frequency signals from the first antenna 25, the radio frequency reader 4 reads the information about the three-axis acceleration of the test object 1 in the radio frequency signals and transmits the information to the controller 5. The controller 5 has a memory that stores a conversion formula, and the controller 5 can convert the three-axis acceleration into an inclination angle according to the conversion formula, and the conversion formula is as follows:

[0046] ax is the X-axis acceleration, ay is the Y-axis acceleration, and az is the Z-axis acceleration.

[0047] θ is the tilt angle, and g is the gravitational acceleration.

[0048] The detection system further comprises a first transfer box, and the moving device is capable of moving the test object 1 to a first receiving slot in the first transfer box, and the first receiving slot defines the reference position of the test object 1. When the test object has been placed in the first receiving slot of the first transfer box, the controller 5 calculates the reference tilt angle of the test object 1 according to the three-axis acceleration detected by the three-axis acceleration sensor 2.

[0049] Subsequently, the moving device is capable of moving the test object 1 from the first receiving slot of the first transfer box to a second receiving slot in the first transfer box or to a third receiving slot in a second transfer box. When the test object 1 is moved to the second receiving slot in the first transfer box or to the third receiving slot in the second transfer box, the second receiving slot or the third receiving slot defines the current position of the test object 1, and the controller 5 calculates the current tilt angle of the test object 1 according to the three-axis acceleration detected by the three-axis acceleration sensor 2.

[0050] Specifically, the first receiving slot in the first transfer box defines the reference position of the test object 1, and the three-axis acceleration of the test object 1 at the reference position defines the reference three-axis acceleration of the test object 1.

[0051] The controller 5 calculates the tilt angle of the test object 1 according to the reference three-axis acceleration of the test object 1, and the tilt angle of the test object 1 at the reference position defines the reference tilt angle of the test object 1. The internal memory of the controller 5 is used to store the reference tilt angle of the test object 1.

[0052] After the controller 5 stores the reference tilt angle of the test object 1, the three-axis acceleration sensor 2 continuously detects the three-axis acceleration of the test object 1. At this time, the three-axis acceleration detected by the three-axis acceleration sensor 2 defines the current three-axis acceleration of the test object 1. The controller 5 calculates the current tilt angle of the test object 1 according to the current three-axis acceleration of the test object 1, and the current tilt angle of the test object 1 is stored in the internal memory of the controller 5.

[0053] When the test object 1 is in an abnormal state, the controller 5 issues an alarm signal. The following lists several different situations in which the controller 5 issues an alarm signal.

[0054] For example, in the first scenario, after the controller 5 obtains the reference tilt angle and the current tilt angle of the test object 1, the controller 5 calculates the angle difference between the current tilt angle and the reference tilt angle of the test object 1. The memory of the controller 5 stores an angle threshold, and the controller 5 determines whether the angle difference is greater than the angle threshold. When the controller 5 determines that the angle difference is greater than the angle threshold, it indicates that the tilt angle of the test object 1 does not meet the safety specification, and the controller 5 sends an alarm signal.

[0055] For example, in the second scenario, the memory of the controller 5 stores an acceleration threshold, and after the controller 5 obtains the reference tilt angle of the test object 1, the controller 5 obtains the three-axis acceleration of the test object 1 again. The controller 5 determines whether the X-axis acceleration, Y-axis acceleration, or Z-axis acceleration of the test object 1 is greater than the acceleration threshold. When the controller 5 determines that the X-axis acceleration, Y-axis acceleration, or Z-axis acceleration of the test object 1 is greater than the acceleration threshold, it indicates that the horizontal or vertical acceleration of the test object 1 does not meet the safety specification, and the controller 5 sends an alarm signal.

[0056] For example, in the third scenario, after the controller 5 obtains the reference tilt angle of the test object 1, the controller 5 obtains the three-axis acceleration of the test object 1 again. The controller 5 determines whether the X-axis acceleration and the Y-axis acceleration of the test object 1 are zero. When the controller 5 determines that the X-axis acceleration and the Y-axis acceleration of the test object 1 are zero, the controller 5 determines whether the Z-axis acceleration of the test object 1 is greater than the acceleration threshold. When the controller 5 determines that the Z-axis acceleration of the test object 1 is greater than the acceleration threshold, it indicates that the vertical acceleration of the test object 1 does not meet the safety specification, and the controller 5 sends an alarm signal.

[0057] When the object placement state detection system is applied to semiconductor manufacturing, the test object 1 is a test wafer, the first transfer box is a first wafer box, the second transfer box is a second wafer box, the first receiving slot is a first wafer slot in the first wafer box, the second receiving slot is a second wafer slot in the first wafer box, and the third receiving slot is a third wafer slot in the second wafer box.

[0058] Figure 3 A schematic diagram of an embodiment of the object placement state detection system of the present application applied to semiconductor manufacturing. Referring to Figure 3The clean room 6 is provided with a first load port unit (LPU) 61, a second load port unit 62, a first wafer cassette 63, a second wafer cassette 64, and a robot 65. The first wafer cassette 63 and the second wafer cassette 64 are each provided with a plurality of wafer slots S. The first wafer cassette 63 is located above the first load port unit 61, and the second wafer cassette 64 is located above the second load port unit 62. The test object 1 is a test wafer. The robot 65 carries the test wafer into any wafer slot S of the first wafer cassette 63 or any wafer slot S of the second wafer cassette 64. The three-axis acceleration sensor 2 on the test wafer detects the three-axis acceleration of the test wafer. The controller 5 determines whether the state of the test wafer complies with safety specifications based on the three-axis acceleration of the test wafer. When the state of the test wafer does not comply with safety specifications, the controller 5 sends an alarm signal to the inspector, so that the inspector can adjust the parameter settings of the first load port unit 61, the second load port unit 62, and the robot 65 in advance to ensure the safety of the actual wafer during handling in the clean room 6.

[0059] Figure 4 A schematic diagram of an embodiment for setting a reference position of a test wafer is shown. As shown in FIG. 6, the test object 1 is a test wafer, and the three-axis acceleration sensor 2 is disposed on the test object 1. When the robot 65 places the test wafer in the lowest wafer slot S (first wafer slot) in the first wafer cassette 63, the lowest wafer slot S in the first wafer cassette 63 is defined as the reference position of the test wafer by the controller 5. In other embodiments, the controller 5 can also define other wafer slots S in the first wafer cassette 63 as the reference position of the test wafer. For example, the controller 5 can define the highest wafer slot S (second wafer slot) in the first wafer cassette 63 as the reference position of the test wafer. Figure 4

[0060] A flowchart of a calibration procedure for a test wafer is shown. Referring to FIG. 7, in step S701, the robot 65 places the test wafer in the reference position defined by the controller 5 in advance. In step S702, the three-axis acceleration sensor 2 on the test wafer detects the reference three-axis acceleration of the test wafer. In step S703, the controller 5 calculates the reference tilt angle of the test wafer based on the reference three-axis acceleration of the test wafer. Figure 5 Figure 5 After the calibration procedure for the test wafer is completed, the state of the test wafer is determined to comply with safety specifications by the object placement state detection method of the present application. Then, a plurality of embodiments of the object placement state detection method will be described.

[0061]

[0062] Figure 6 ​​Figure 1 is a schematic diagram of a first embodiment of the method for detecting the placement state of an object according to the present application. In step S601, the triaxial acceleration sensor 2 on the test wafer detects the current triaxial acceleration of the test wafer, wherein the current triaxial acceleration includes the X-axis acceleration, the Y-axis acceleration and the Z-axis acceleration of the test wafer. In step S602, the controller 5 determines whether the X-axis acceleration and the Y-axis acceleration of the test wafer are both zero. If yes, step S603 is followed. If no, step S601 is returned to.

[0063] Specifically, when the X-axis acceleration and the Y-axis acceleration of the test wafer are both zero, it is possible that the robot arm 65 has placed the test wafer in the wafer slot, or the robot arm 65 has transported the test wafer into the wafer cassette, but the test wafer is still on the robot arm 65 and has not fallen into the wafer slot.

[0064] In step S603, the controller 5 calculates the current tilt angle of the test wafer according to the current triaxial acceleration of the test wafer. In step S604, the controller 5 calculates the angle difference between the current tilt angle of the test wafer and the reference tilt angle. In step S605, the controller 5 determines whether the angle difference is greater than the angle threshold. If yes, step S606 is followed. If no, step S601 is returned to.

[0065] In step S606, the controller 5 issues an alarm signal.

[0066] For example, under the premise that the robot arm 65 places the test wafer in the wafer slot of the wafer cassette, if the controller 5 determines that the angle difference between the current tilt angle of the test wafer and the reference tilt angle is greater than the angle threshold at this time, the controller 5 issues an alarm signal.

[0067] For example, under the premise that the robot arm 65 sends the test wafer into the wafer cassette and the test wafer is still on the robot arm 65, if the controller 5 determines that the angle difference between the current tilt angle of the test wafer and the reference tilt angle is greater than the angle threshold at this time, the controller 5 issues an alarm signal.

[0068] Figure 7 Figure 2 is a schematic diagram of a third embodiment of the method for detecting the placement state of an object according to the present application. Referring to Figure 7 In step S701, the triaxial acceleration sensor 2 on the test wafer detects the current triaxial acceleration of the test wafer, wherein the current triaxial acceleration includes the X-axis acceleration, the Y-axis acceleration and the Z-axis acceleration of the test wafer. In step S702, the controller 5 determines whether any one of the X-axis acceleration, the Y-axis acceleration and the Z-axis acceleration of the test wafer is greater than the acceleration threshold. If yes, step S703 is followed. If no, step S701 is returned to. In step S703, the controller 5 issues an alarm signal.

[0069] For example, if the test wafer is on the robot 65 and the robot 65 is moving toward the wafer cassette, the controller 5 sends an alarm signal if the three-axis acceleration sensor 2 detects that any one of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration of the test wafer is greater than the acceleration threshold value.

[0070] For example, if the test wafer is on the robot 65 and the robot 65 is moving away from the wafer cassette, the controller 5 sends an alarm signal if the three-axis acceleration sensor 2 detects that any one of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration of the test wafer is greater than the acceleration threshold value.

[0071] For example, if the test wafer is falling into the wafer slot of the wafer cassette from the robot 65, the controller 5 sends an alarm signal if the three-axis acceleration sensor 2 detects that any one of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration of the test wafer is greater than the acceleration threshold value.

[0072] For example, if the test wafer has been placed into the wafer slot of the wafer cassette by the robot 65, the controller 5 sends an alarm signal if the three-axis acceleration sensor 2 detects that any one of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration of the test wafer is greater than the acceleration threshold value.

[0073] For example, if the test wafer has been sent into the wafer cassette by the robot 65, but the test wafer is still on the robot 65 and has not fallen into the wafer slot, the controller 5 sends an alarm signal if the three-axis acceleration sensor 2 detects that any one of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration of the test wafer is greater than the acceleration threshold value.

[0074] Figure 8 FIG. 4 is a schematic diagram of a fourth embodiment of the method for detecting the placement state of an object of the present application. Referring to FIG. 4, the method for detecting the placement state of an object of the present application includes the following steps S801-S804. Figure 8 In step S801, the three-axis acceleration sensor 2 on the test wafer detects the current three-axis acceleration of the test wafer, and the current three-axis acceleration includes the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration. In step S802, the controller 5 determines whether the X-axis acceleration and the Y-axis acceleration are both zero. If yes, the following step S803 is performed. If no, the process returns to step S801.

[0075] In step S803, the controller 5 determines whether the Z-axis acceleration is greater than the acceleration threshold value. If yes, the following step S804 is performed. If no, the process returns to step S801. In step S804, the controller 5 sends an alarm signal.

[0076] For example, if the test wafer is falling into the wafer slot of the wafer cassette from the robot 65, the controller 5 sends an alarm signal if the three-axis acceleration sensor 2 detects that any one of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration of the test wafer is greater than the acceleration threshold value.

[0077] [Advantages of the embodiments]

[0078] One of the advantages of the present application is that the object placement state detection system, detection method and detection device provided by the present application can automatically send an alarm signal to the detection personnel as soon as the placement state of the test object is found to be abnormal, so that the detection personnel can quickly eliminate the abnormal condition. In this way, the detection time is saved and the probability of missed detection and false detection is reduced.

[0079] The above disclosure is only the preferred and feasible embodiments of the present application, and does not limit the scope of the claims of the present application. Therefore, any equivalent technical changes made according to the content of the specification and drawings of the present application are included in the scope of the claims of the present application.

Claims

1. A system for detecting a placement state of an object, the system comprising: a test object; a three-axis acceleration sensor disposed on the test object and configured to detect a three-axis acceleration of the test object, the three-axis acceleration including an X-axis acceleration, a Y-axis acceleration, and a Z-axis acceleration; and a controller configured to calculate a current tilt angle of the test object based on the three-axis acceleration, to calculate an angle difference between the current tilt angle and a reference tilt angle of the test object, and to determine whether the angle difference is greater than an angle threshold value; the controller configured to issue an alarm signal when the angle difference is greater than the angle threshold value. 2.The system of claim 1, wherein the controller is configured to calculate the reference tilt angle of the test object based on the three-axis acceleration detected by the three-axis acceleration sensor when the test object is located at a reference position at a first time point, and to calculate the current tilt angle of the test object based on the three-axis acceleration detected by the three-axis acceleration sensor after the first time point. 3.The system of claim 1, wherein the controller is configured to determine whether any one of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration is greater than an acceleration threshold value, and to issue the alarm signal when any one of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration is greater than the acceleration threshold value. 4.The system of claim 1, wherein the controller is configured to determine whether the X-axis acceleration and the Y-axis acceleration are both zero, and to determine whether the Z-axis acceleration is greater than an acceleration threshold value when the X-axis acceleration and the Y-axis acceleration are both zero, and to issue the alarm signal when the Z-axis acceleration is greater than the acceleration threshold value. 5.The system of claim 1, wherein the three-axis acceleration sensor comprises a sensing substrate and a first antenna, the sensing substrate connected to the first antenna, the system further comprising a second antenna and a radio frequency reader, the first antenna communicatively connected to the second antenna, and the radio frequency reader electrically connected to the second antenna and the controller. 6.The system of claim 1, further comprising a first transfer box, the controller configured to calculate the reference tilt angle based on the three-axis acceleration detected by the three-axis acceleration sensor when the test object is moved into a first receiving slot of the first transfer box, and to calculate the current tilt angle based on the three-axis acceleration detected by the three-axis acceleration sensor when the test object is moved from the first receiving slot to a second receiving slot of the first transfer box or to a third receiving slot of a second transfer box. ​ 7. The system of claim 6, wherein the test object is a test wafer, the first transport box is a first wafer box, the first receiving slot is a first wafer slot of the first wafer box, the second receiving slot is a second wafer slot of the first wafer box, the second transport box is a second wafer box, and the third receiving slot is a third wafer slot of the second wafer box.

8. The system of claim 1, wherein the controller is configured to determine whether the X-axis acceleration and the Y-axis acceleration are both zero, and to calculate the current tilt angle when the X-axis acceleration and the Y-axis acceleration are both zero.

9. A method of detecting a state of an object, the method comprising: providing a test object, a three-axis acceleration sensor disposed on the test object; detecting, by the three-axis acceleration sensor, a three-axis acceleration of the test object, the three-axis acceleration comprising an X-axis acceleration, a Y-axis acceleration, and a Z-axis acceleration; calculating, by a controller, a current tilt angle of the test object based on the three-axis acceleration; calculating, by the controller, an angle difference between the current tilt angle and a reference tilt angle of the test object; determining, by the controller, whether the angle difference is greater than an angle threshold; and issuing, by the controller, an alert signal when the angle difference is greater than the angle threshold.

10. The method of claim 9, wherein the reference tilt angle is calculated by the controller based on the three-axis acceleration detected by the three-axis acceleration sensor when the test object is at a reference position at a first time point, and the current tilt angle is calculated by the controller based on the three-axis acceleration detected by the three-axis acceleration sensor after the first time point.

11. The method of claim 9, further comprising determining, by the controller, whether the X-axis acceleration and the Y-axis acceleration are both zero, and calculating the current tilt angle when the X-axis acceleration and the Y-axis acceleration are both zero.

12. The method of claim 9, further comprising determining, by the controller, whether any one of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration is greater than an acceleration threshold, and issuing the alert signal when any one of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration is greater than the acceleration threshold. ​ 13. The method of claim 9, further comprising the step of determining, by the controller, whether the X-axis acceleration and the Y-axis acceleration are both zero; determining, by the controller, whether the Z-axis acceleration is greater than an acceleration threshold when the X-axis acceleration and the Y-axis acceleration are both zero; and issuing, by the controller, the alert signal when the Z-axis acceleration is greater than the acceleration threshold.

14. The article placement status detection method according to claim 9, further comprising: moving the test object into a first receiving slot of a first transfer cassette by a moving device; calculating, by the controller, the reference tilt angle based on the three-axis acceleration detected by the three-axis acceleration sensor.

15. The article placement status detection method according to claim 14, further comprising: moving the test object from the first receiving slot to a second receiving slot of the first transfer cassette or to a third receiving slot of a second transfer cassette by the moving device; and calculating, by the controller, the current tilt angle based on the three-axis acceleration detected by the three-axis acceleration sensor.

16. The method of claim 15, wherein the test object is a test wafer, the first transfer cassette is a first wafer cassette, the second transfer cassette is a second wafer cassette, the first receiving slot is a first wafer slot of the first wafer cassette, the second receiving slot is a second wafer slot of the first wafer cassette, and the third receiving slot is a third wafer slot of the second wafer cassette.

17. An apparatus for detecting a state of an object, the apparatus comprising: a test object; a three-axis acceleration sensor disposed on the test object and configured to detect a three-axis acceleration of the test object; a reference three-axis acceleration of the test object is defined by the three-axis acceleration detected by the three-axis acceleration sensor when the test object is at a reference position at a first time point; and a current three-axis acceleration of the test object is defined by the three-axis acceleration detected by the three-axis acceleration sensor after the first time point.

18. The apparatus of claim 17, wherein the three-axis acceleration sensor comprises a sensing substrate and a first antenna, and the sensing substrate is connected to the first antenna.

19. The apparatus of claim 17, wherein the test object is a test wafer, and the reference position is a wafer slot of a wafer cassette. ​

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