Pre-positioning equipment for wafer processing

Abstract

The invention relates to pre-positioning equipment for wafer processing, which comprises a working table, a base is rotatably arranged on the top end surface of the working table, a rotation driving device is arranged between the base and the working table, a bearing centering plate is movably arranged on the top end surface of the base, and a positioning device is arranged on the bearing centering plate. A translation driving device is arranged between the bearing centering plate and the base; before edge searching is carried out on the wafer, the wafer with the drooping edge is leveled step by step, and then the leveled wafer is dispersedly supported and kept in a flat state. According to the invention, the leveled wafer can be dispersed, adsorbed and fixed without shifting and shaking during the period of being driven to rotate for a plurality of circles and being subjected to edge searching, the wafer can be kept in a flat state in real time, errors can be reduced during edge searching of the wafer, and deviation of pre-positioning of the wafer cannot be caused.

Description

Technical Field

[0001] This invention relates to the field of pre-positioning equipment for wafer processing, and specifically to a pre-positioning equipment for wafer processing. Background Technology

[0002] A wafer is a thin sheet of semiconductor, such as crystalline silicon, used to manufacture integrated circuits.

[0003] Most existing wafers are round. After the wafer is cut, it is usually placed on a wafer rack with enough space to prevent the wafer from being bumped or scratched during the handling process.

[0004] Before further processing, the wafer needs to be pre-positioned using a pre-positioning device.

[0005] However, existing wafer processing positioning equipment cannot first gradually flatten wafers that have already experienced edge sagging before performing edge finding on the wafers, and then disperse and support the flattened wafers to maintain their flatness.

[0006] It is impossible to ensure that the flattened wafer is dispersed, adsorbed and fixed without shifting or shaking during the edge-finding process, and to maintain a flat state in real time. It is also impossible to reduce errors during the edge-finding process, which can easily lead to deviations in the pre-positioning of the wafer.

[0007] The purpose of this invention is to design a pre-positioning device for wafer processing to address the problems existing in the prior art. Summary of the Invention

[0008] In view of the problems existing in the prior art, the present invention provides a pre-positioning device for wafer processing, which can effectively solve at least one of the problems existing in the prior art.

[0009] The technical solution of this invention is:

[0010] A pre-positioning device for wafer processing includes:

[0011] A workbench, wherein a base is rotatably mounted on the top surface of the workbench, a rotation drive device is provided between the base and the workbench, a shift centering plate is movably mounted on the top surface of the base, and a translation drive device is provided between the shift centering plate and the base.

[0012] Three lifting frames are provided at equal angles on the outer side wall of the base. A lifting drive device is provided between the three lifting frames and the base. A receiving frame is movably provided on the lifting frame and below the supporting centering plate. The receiving frame is movably provided along the radial direction of the base. A radial drive device is provided between the receiving frame and the lifting frame.

[0013] An airflow seat is provided on the top surface of the receiving frame and below the centering plate. An airflow driving device is provided on the receiving frame and communicates with the airflow seat. A laser sensor is provided on the end face of the receiving frame away from the base and outside the airflow seat. An edge-finding detection device is provided on the top surface of the worktable and on one side of one of the lifting frames.

[0014] When each receiving frame moves the same predetermined distance toward the base, the three lifting frames are driven to rise simultaneously, which in turn drives the three airflow seats to rise simultaneously. During the simultaneous rise of the three airflow seats, they are driven to generate upward airflow. With the cooperation of the three airflow seats and the transfer centering plate, the wafers that have drooped at the edges supported on the transfer centering plate are first gradually leveled, and then the leveled wafers supported on the transfer centering plate are brought into contact with the top surfaces of the three airflow seats. The leveled wafers are dispersed and supported and kept in a flat state.

[0015] When the leveled wafer supported on the centering plate comes into contact with the top surfaces of the three gas flow seats, the three lifting frames are driven to rise simultaneously, which in turn drives the three gas flow seats to rise simultaneously. During the simultaneous rise of the three gas flow seats, they are driven to generate a downward and constant airflow. Then the base is driven to rotate several times, so that the leveled wafer is first attracted and fixed by the three gas flow seats and separated from the centering plate, and then driven to rotate several times.

[0016] Furthermore, a number of contact balls are arranged around the outside of the receiving frame. The contact balls are lifted and positioned on the receiving frame and between the airflow seat and the laser sensor. A lifting device is provided between the contact balls and the receiving frame.

[0017] Several contact balls at various locations are driven to rise above the airflow seats during the simultaneous rise of the three airflow seats and the simultaneous generation of upward airflow, so as to maintain contact with the wafer as the wafer with drooping edges supported on the transfer centering plate is gradually leveled by the three airflow seats and the transfer centering plate, and to maintain contact with the wafer before the leveled wafer supported on the transfer centering plate comes into contact with the top surface of the three airflow seats;

[0018] Several contact balls at various locations are driven to rise to contact the wafer when the leveled wafer is simultaneously adsorbed and fixed by three airflow seats and separated from the transfer centering plate, so as to increase the constraint on the leveled wafer during the period when the leveled wafer is driven to rotate several times.

[0019] Furthermore, the lifting device includes a lifting ring plate, which is lifted and disposed outside the receiving frame and below the laser sensor. A compensating spring is provided between the contact ball and the lifting ring plate. Two support seats are provided outside the receiving frame and below the lifting ring plate. The two support seats are arranged around the receiving frame. A first telescopic member is provided between the support seats and the lifting ring plate.

[0020] Furthermore, the rotation drive device includes a connecting seat, which is disposed on the top surface of the worktable and located below the base, and a servo rotation motor is disposed between the connecting seat and the base.

[0021] Furthermore, the translation drive device is an XY-axis linear module; the lifting drive device includes three Z-axis linear modules, which are disposed between the lifting frame and the base.

[0022] Furthermore, the radial drive device includes a second telescopic member disposed between the lifting frame and the receiving frame, with the bottom end of the receiving frame located inside the lifting frame.

[0023] Furthermore, the airflow seat includes an airflow seat body, which is disposed on the top surface of the receiving frame and located below the transfer centering plate. The airflow seat body is provided with a flow cavity, and the top surface of the airflow seat body is provided with a plurality of airflow holes communicating with the flow cavity.

[0024] The airflow driving device includes a bidirectional air pump mounted on the housing; a pipe, one end of which is connected to the bidirectional air pump, and the other end of which passes through the housing, the airflow seat body, and is connected to the flow cavity.

[0025] Furthermore, the edge-finding detection device includes a moving linear module, which is disposed on the top surface of the workbench and located on one side of one of the lifting frames. A bracket is provided on the moving linear module, a laser projector is disposed on the bracket and above the centering plate, and a laser receiver is disposed on the bracket and below the laser projector.

[0026] Therefore, the present invention provides the following effects and / or advantages:

[0027] 1) The transfer centering plate is used to support the wafers loaded from external equipment;

[0028] Each of the aforementioned receiving racks is driven to move in a radial direction away from the base when the transfer centering plate supports the wafer loaded from the external equipment, thereby driving the corresponding laser sensor to move in a radial direction away from the base, and periodically emitting and receiving laser pulses upward during the radial movement of the corresponding laser sensor away from the base.

[0029] Each of the aforementioned housings is driven to stop moving first when the laser pulse emitted by the corresponding laser sensor is not received, and then moves the same predetermined distance toward the base. Each of the aforementioned radial drive devices is used to drive the corresponding housing to move.

[0030] When each receiving frame moves the same predetermined distance toward the base, the three lifting frames are driven to rise simultaneously, which in turn drives the three airflow seats to rise simultaneously. During the simultaneous rise of the three airflow seats, they are driven to generate upward airflow. With the cooperation of the three airflow seats and the transfer centering plate, the wafers that have drooped at the edges supported on the transfer centering plate are first gradually leveled, and then the leveled wafers supported on the transfer centering plate are brought into contact with the top surfaces of the three airflow seats. The leveled wafers are dispersed and supported and kept in a flat state.

[0031] When the flattened wafer supported on the centering plate comes into contact with the top surface of the three airflow seats, the three lifting frames are driven to rise simultaneously, which in turn drives the three airflow seats to rise simultaneously. During the simultaneous rise of the three airflow seats, they are driven to generate a downward and constant airflow. Then the base is driven to rotate several times, so that the flattened wafer is first attracted and fixed by the three airflow seats and separated from the centering plate. Then it is driven to rotate several times, so that the flattened wafer is dispersed, attracted and fixed during the rotation and will not shift or shake, and can maintain a flat state in real time.

[0032] The edge-finding detection device is used to find the edges of the leveled wafer during the period when the leveled wafer is rotated several times, so as to determine the center and notch position of the leveled wafer.

[0033] When determining the center and notch position of the leveled wafer, the centering plate is first driven to move to the predetermined position, then the base is driven to rotate by a predetermined angle, and then the three lifting frames are driven to descend simultaneously, which in turn drives the three airflow seats to descend simultaneously. During the simultaneous descent of the three airflow seats, the airflow is no longer generated, so that the leveled wafer is supported by the centering plate again, and the center of the leveled wafer coincides with the center of the centering plate, and the notch of the leveled wafer is at the predetermined position.

[0034] The rotation drive device is used to drive the base to move, the translation drive device is used to drive the centering plate to move, the lifting drive device is used to drive the three lifting frames to move, and each of the airflow drive devices is used to drive the corresponding airflow seat to move.

[0035] In summary: the system can gradually flatten wafers with sagging edges before edge finding, and then disperse and support the flattened wafers while maintaining their flatness; the system can ensure that the flattened wafers are dispersed, attracted, and fixed during edge finding without shifting or shaking, and maintain their flatness in real time, even when rotated several times; the system can reduce errors during wafer edge finding and prevent deviations in the pre-positioning of the wafers.

[0036] 2) Several contact balls at various locations are driven to rise above the airflow seats during the simultaneous rise of the three airflow seats and the simultaneous generation of upward airflow, so as to maintain contact with the wafer during the gradual leveling of the wafer supported on the transfer centering plate by the three airflow seats and the transfer centering plate, thereby cooperating with the three airflow seats and the transfer centering plate to improve the leveling quality of the wafer and reduce the displacement of the wafer on the transfer centering plate, so as to maintain contact with the wafer before the leveled wafer supported on the transfer centering plate comes into contact with the top surface of the three airflow seats, thereby making the leveled wafer supported on the transfer centering plate smoothly and smoothly transition to contact with the top surface of the three airflow seats;

[0037] Several contact balls at various locations are driven to rise to contact the wafer when the leveled wafer is simultaneously adsorbed and fixed by the three airflow seats and separated from the transfer centering plate, so as to increase the constraint on the leveled wafer during the period when the leveled wafer is driven to rotate several times, thereby improving the stability of the leveled wafer on the three airflow seats during the period when the leveled wafer is driven to rotate several times.

[0038] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0039] It should be understood that the above summary and the following detailed description of the invention are exemplary and explanatory, and are intended to provide further explanation of the invention as claimed. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of the present invention.

[0041] Figure 2 For the corresponding Figure 1 Enlarged view of part A.

[0042] Explanation of reference numerals in the attached figures:

[0043] Workbench 1, base 2, centering plate 3, lifting frame 4, housing frame 5, laser sensor 6, contact ball 7, lifting ring plate 8, compensating spring 9, support seat 10, first telescopic component 11, connecting seat 12, servo rotating motor 13, XY linear module 14, Z linear module 15, second telescopic component 16, airflow seat body 17, flow cavity 18, airflow hole 19, bidirectional air pump 20, pipe 21, moving linear module 22, bracket 23, laser projector 24, laser receiver 25. Detailed Implementation

[0044] To facilitate understanding by those skilled in the art, the structure of the present invention will now be described in further detail with reference to the accompanying drawings:

[0045] refer to Figure 1-2 A pre-positioning device for wafer processing, comprising:

[0046] A workbench 1, a base 2 is rotatably mounted on the top surface of the workbench 1, a rotation drive device is provided between the base 2 and the workbench 1, a shift centering plate 3 is movably mounted on the top surface of the base 2, and a translation drive device is provided between the shift centering plate 3 and the base 2.

[0047] Three lifting frames 4 are provided at equal angles on the outer side wall of the base 2. A lifting drive device is provided between the three lifting frames 4 and the base 2. A receiving frame 5 is movably provided on the lifting frame 4 and below the supporting centering plate 3. The receiving frame 5 is movably provided along the radial direction of the base 2. A radial drive device is provided between the receiving frame 5 and the lifting frame 4.

[0048] An airflow seat is provided on the top surface of the receiving frame 5 and below the transfer centering plate 3. An airflow driving device is provided on the receiving frame 5 and communicates with the airflow seat. A laser sensor 6 is provided on the end face of the receiving frame 5 away from the base 2 and outside the airflow seat. An edge-finding detection device is provided on the top surface of the worktable 1 and on one side of one of the lifting frames 4.

[0049] The centering plate 3 is used to support the wafers loaded from external equipment;

[0050] Each of the aforementioned receiving racks 5 is driven to move in a radial direction away from the base 2 when the transfer centering plate 3 supports the wafer loaded from the external equipment, so as to drive the corresponding laser sensor 6 to move in a radial direction away from the base 2, and periodically emit and receive laser pulses upward during the radial movement of the corresponding laser sensor 6 away from the base 2.

[0051] Each of the aforementioned housings 5 ​​is driven to stop moving first when the laser pulse emitted by the corresponding laser sensor 6 is not received, and then moves the same predetermined distance toward the base 2. Each of the aforementioned radial drive devices is used to drive the corresponding housing 5 to move.

[0052] When each of the receiving frames 5 moves the same predetermined distance toward the base 2, the three lifting frames 4 are driven to rise simultaneously, which in turn drives the three airflow seats to rise simultaneously. During the simultaneous rise of the three airflow seats, they are driven to generate upward airflow. With the cooperation of the three airflow seats and the transfer centering plate 3, the wafers that have drooped at the edges and are supported on the transfer centering plate 3 are gradually leveled. Then, the leveled wafers supported on the transfer centering plate 3 are brought into contact with the top surfaces of the three airflow seats. The leveled wafers are dispersed and supported and kept in a flat state.

[0053] When the flattened wafer supported on the centering plate 3 comes into contact with the top surface of the three airflow seats, the three lifting frames 4 are driven to rise simultaneously, which in turn drives the three airflow seats to rise simultaneously. During the simultaneous rise of the three airflow seats, they are driven to generate a downward and constant airflow. Then the base 2 is driven to rotate several times, so that the flattened wafer is first attracted and fixed by the three airflow seats and separated from the centering plate 3. Then it is driven to rotate several times, so that the flattened wafer is dispersed and attracted and fixed during the rotation, without shifting or shaking, and can maintain a flat state in real time.

[0054] The edge-finding detection device is used to find the edges of the leveled wafer during the period when the leveled wafer is rotated several times, so as to determine the center and notch position of the leveled wafer.

[0055] When determining the center and notch position of the flattened wafer, the centering plate 3 is first driven to translate to the predetermined position, then the base 2 is driven to rotate by a predetermined angle, and then the three lifting frames 4 are driven to descend simultaneously, which in turn drives the three airflow seats to descend simultaneously. During the simultaneous descent of the three airflow seats, the airflow is no longer generated, so that the flattened wafer is supported by the centering plate 3 again, and the center of the flattened wafer coincides with the center of the centering plate 3, and the notch of the flattened wafer is at the predetermined position.

[0056] The rotation drive device is used to drive the base 2 to move, the translation drive device is used to drive the centering plate 3 to move, the lifting drive device is used to drive the three lifting frames 4 to move, and each of the airflow drive devices is used to drive the corresponding airflow seat to move.

[0057] The outer periphery of the receiving frame 5 is provided with several contact balls 7, which are raised and lowered on the receiving frame 5 and located between the airflow seat and the laser sensor 6. A lifting device is provided between the several contact balls 7 and the receiving frame 5.

[0058] The contact balls 7 at various locations are driven to rise above the airflow seats during the simultaneous rise of the three airflow seats and the simultaneous generation of upward airflow, so as to maintain contact with the wafer during the gradual leveling of the wafer supported on the transfer centering plate 3, which has experienced edge sagging, by the three airflow seats and the transfer centering plate 3. This cooperates with the three airflow seats and the transfer centering plate 3 to improve the leveling quality of the wafer and reduce the displacement of the wafer on the transfer centering plate 3, so as to maintain contact with the wafer before the leveled wafer supported on the transfer centering plate 3 comes into contact with the top surface of the three airflow seats, thereby allowing the leveled wafer supported on the transfer centering plate 3 to smoothly and smoothly transition to contact with the top surface of the three airflow seats.

[0059] The contact balls 7 at various locations are driven to rise to contact the wafer when the leveled wafer is simultaneously adsorbed and fixed by the three airflow seats and separated from the transfer centering plate 3, so as to increase the constraint on the leveled wafer during the period when the leveled wafer is driven to rotate several times, thereby improving the stability of the leveled wafer on the three airflow seats during the period when the leveled wafer is driven to rotate several times.

[0060] The lifting device includes a lifting ring plate 8, which is lifted and positioned outside the receiving frame 5 and below the laser sensor 6. A compensating spring 9 is provided between the contact ball 7 and the lifting ring plate 8. Two support seats 10 are provided outside the receiving frame 5 and below the lifting ring plate 8. The two support seats 10 are arranged around the receiving frame 5. A first telescopic member 11 is provided between the support seats 10 and the lifting ring plate 8.

[0061] The rotation drive device includes a connecting seat 12, which is disposed on the top surface of the worktable 1 and located below the base 2. A servo rotation motor 13 is disposed between the connecting seat 12 and the base 2.

[0062] The translation drive device is an XY linear module 14; the lifting drive device includes three Z linear modules 15, which are disposed between the lifting frame 4 and the base 2.

[0063] The radial drive device includes a second telescopic member 16, which is disposed between the lifting frame 4 and the receiving frame 5, with the bottom end of the receiving frame 5 located inside the lifting frame 4.

[0064] The airflow seat includes an airflow seat body 17, which is disposed on the top surface of the receiving frame 5 and located below the transfer centering plate 3. The airflow seat body 17 is provided with a flow cavity 18, and the top surface of the airflow seat body 17 is provided with a plurality of airflow holes 19 that communicate with the flow cavity 18.

[0065] The airflow drive device includes a bidirectional air pump 20, which is mounted on the housing 5; and a pipe 21, one end of which is connected to the bidirectional air pump 20, and the other end of which passes through the housing 5, the airflow seat body 17, and is connected to the flow cavity 18.

[0066] The edge-finding detection device includes a moving linear module 22, which is disposed on the top surface of the workbench 1 and located on one side of one of the lifting frames 4. A bracket 23 is disposed on the moving linear module 22. A laser projector 24 is disposed on the bracket 23 and above the centering plate 3. A laser receiver 25 is disposed on the bracket 23 and below the laser projector 24.

[0067] It should be noted that any reference signs placed between parentheses in the claims should not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0068] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0069] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0070] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A pre-positioning device for wafer processing, characterized in that: include: A workbench, wherein a base is rotatably mounted on the top surface of the workbench, a rotation drive device is provided between the base and the workbench, a shift centering plate is movably mounted on the top surface of the base, and a translation drive device is provided between the shift centering plate and the base. Three lifting frames are provided at equal angles on the outer side wall of the base. A lifting drive device is provided between the three lifting frames and the base. A receiving frame is movably provided on the lifting frame and below the supporting centering plate. The receiving frame is movably provided along the radial direction of the base. A radial drive device is provided between the receiving frame and the lifting frame. An airflow seat is provided on the top surface of the receiving frame and below the centering plate. An airflow driving device is provided on the receiving frame and communicates with the airflow seat. A laser sensor is provided on the end face of the receiving frame away from the base and outside the airflow seat. An edge-finding detection device is provided on the top surface of the worktable and on one side of one of the lifting frames. When each receiving frame moves the same predetermined distance toward the base, the three lifting frames are driven to rise simultaneously, which in turn drives the three airflow seats to rise simultaneously. During the simultaneous rise of the three airflow seats, they are driven to generate upward airflow. With the cooperation of the three airflow seats and the transfer centering plate, the wafers that have drooped at the edges supported on the transfer centering plate are first gradually leveled, and then the leveled wafers supported on the transfer centering plate are brought into contact with the top surfaces of the three airflow seats. The leveled wafers are dispersed and supported and kept in a flat state. When the leveled wafer supported on the centering plate comes into contact with the top surfaces of the three gas flow seats, the three lifting frames are driven to rise simultaneously, which in turn drives the three gas flow seats to rise simultaneously. During the simultaneous rise of the three gas flow seats, they are driven to generate a downward and constant airflow. Then the base is driven to rotate several times, so that the leveled wafer is first attracted and fixed by the three gas flow seats and separated from the centering plate, and then driven to rotate several times.

2. The pre-positioning device for wafer processing according to claim 1, characterized in that: The outer periphery of the receiving frame is surrounded by several contact balls, which are raised and lowered on the receiving frame and located between the airflow seat and the laser sensor. A lifting device is provided between the contact balls and the receiving frame. Several contact balls at various locations are driven to rise above the airflow seats during the simultaneous rise of the three airflow seats and the simultaneous generation of upward airflow, so as to maintain contact with the wafer as the wafer with drooping edges supported on the transfer centering plate is gradually leveled by the three airflow seats and the transfer centering plate, and to maintain contact with the wafer before the leveled wafer supported on the transfer centering plate comes into contact with the top surface of the three airflow seats; Several contact balls at various locations are driven to rise to contact the wafer when the leveled wafer is simultaneously adsorbed and fixed by three airflow seats and separated from the transfer centering plate, so as to increase the constraint on the leveled wafer during the period when the leveled wafer is driven to rotate several times.

3. The pre-positioning device for wafer processing according to claim 2, characterized in that: The lifting device includes a lifting ring plate, which is lifted and disposed outside the receiving frame and below the laser sensor. A compensating spring is provided between the contact ball and the lifting ring plate. Two support seats are provided outside the receiving frame and below the lifting ring plate. The two support seats are arranged around the receiving frame. A first telescopic member is provided between the support seats and the lifting ring plate.

4. The pre-positioning device for wafer processing according to claim 1, characterized in that: The rotation drive device includes a connecting seat, which is disposed on the top surface of the worktable and located below the base, and a servo rotation motor is disposed between the connecting seat and the base.

5. The pre-positioning device for wafer processing according to claim 1, characterized in that: The translation drive device is an XY linear module; the lifting drive device includes three Z linear modules, which are disposed between the lifting frame and the base.

6. The pre-positioning device for wafer processing according to claim 1, characterized in that: The radial drive device includes a second telescopic member disposed between the lifting frame and the receiving frame, with the bottom end of the receiving frame located inside the lifting frame.

7. The pre-positioning device for wafer processing according to claim 1, characterized in that: The airflow seat includes an airflow seat body, which is disposed on the top surface of the receiving frame and located below the transfer centering plate. The airflow seat body is provided with a flow cavity, and the top surface of the airflow seat body is provided with a number of airflow holes that communicate with the flow cavity. The airflow driving device includes a bidirectional air pump mounted on the housing; a pipe, one end of which is connected to the bidirectional air pump, and the other end of which passes through the housing, the airflow seat body, and is connected to the flow cavity.

8. A pre-positioning device for wafer processing according to any one of claims 1-7, characterized in that: The edge-finding detection device includes a moving linear module, which is disposed on the top surface of the workbench and located on one side of one of the lifting frames. A bracket is provided on the moving linear module, a laser projector is disposed on the bracket and above the centering plate, and a laser receiver is disposed on the bracket and below the laser projector.

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