Positioning device of semiconductor wafer

Abstract

The invention belongs to the technical field of semiconductor production, and discloses a semiconductor wafer positioning device which comprises a silicon wafer and a bearing mechanism, the silicon wafer is provided with a positioning edge, the bearing mechanism comprises an objective table for placing the silicon wafer, the objective table is fixedly connected to a base, and the semiconductor wafer positioning device further comprises a centering mechanism and a positioning mechanism. According to the silicon wafer centering device, after the silicon wafer is placed on the bearing mechanism, the first motor is started to center the silicon wafer, then the second motor is started to drive the silicon wafer to rotate through the rubber roller, and as the positioning edge makes contact with the stopping plate, the front side face of the stopping plate abuts against the straight line side face where the positioning edge is located; according to the design, the orientation of the final positioning edge of each silicon wafer is kept consistent, so that the silicon wafer can be directly placed at a specified position of the wafer carrying table when a follow-up mechanical arm and other devices transfer the silicon wafer to photoetching equipment, and the time required for multiple times of positioning calibration in the follow-up photoetching step is shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor production, and in particular relates to a semiconductor wafer positioning device. Background Art

[0002] After rolling, polishing and slicing, the silicon crystal rod forms a silicon wafer, that is, a semiconductor wafer. After the rolling of the silicon crystal rod is completed, a plane will be polished on the silicon rod so that the cut silicon wafer has a positioning edge. This positioning edge plays a role in the initial positioning and calibration in the subsequent photolithography process. At the same time, the positioning edge can also distinguish the type and crystal orientation of the silicon wafer. After the ground and cleaned silicon wafer is sent to the photolithography equipment, the wafer stage of the photolithography equipment will identify the positioning edge on the silicon wafer through the visual system, thereby controlling the movement and rotation of the wafer stage, so that the photolithography head can accurately carry out photolithography on the wafer.

[0003] When existing wafer positioning equipment positions the wafer, it often only makes the center of the wafer coincide with the center of the stage of the positioning mechanism, while the orientation of the positioning edges of the wafer is different. This means that in the subsequent photolithography steps, the wafer still needs to be identified and positioned. When photolithography is performed on wafers in large quantities, these identification and positioning steps will waste a lot of time cumulatively, thus affecting the overall production efficiency of the batch. At the same time, after long-term use, the wafer stage is still prone to mechanical wear and other problems, resulting in a decrease in positioning accuracy, thus affecting the positioning accuracy of the photolithography step. Summary of the invention

[0004] The object of the present invention is to provide a semiconductor wafer positioning device to solve the problems raised in the above background technology.

[0005] In order to achieve the above-mentioned object, the present invention provides the following technical solution: a positioning device for a semiconductor wafer, comprising a silicon wafer and a carrying mechanism, wherein the silicon wafer is provided with a positioning edge, the carrying mechanism comprises a stage for placing the silicon wafer, the stage is fixedly connected to a base, and further comprises:

[0006] A centering mechanism, the centering mechanism comprises a center frame and a plurality of side frames fixed symmetrically to the sides of the center frame, the top surface of the side frame is provided with a first slide groove, a positioning mechanism is arranged in the first slide groove of one of the side frames, and first sliders are slidably connected in the first slide grooves of the other side frames, and a screw rod is rotatably installed inside the side frame to drive the positioning mechanism and the first slider to gather and disperse;

[0007] The positioning mechanism includes a second slider slidably connected in the first slide groove, a second motor is embedded in the interior of the second slider, the top surface of the second slider is fixedly connected to the first frame, the output shaft of the second motor is fixedly sleeved with a rubber roller located in the first frame, one side of the first frame is fixedly connected to the second frame, a stop plate is rotatably installed inside the first frame, a torsion spring is arranged between the stop plate and the first frame to rotate the stop plate toward the center of the silicon wafer, and a buffer pad abutting against the front side of the stop plate is fixedly connected to the side of the second frame.

[0008] Preferably, the bearing mechanism further comprises a hinged plate hinged to the side of the loading platform, and a plurality of the hinged plates are provided, a telescopic rod is hingedly installed between the bottom surface of the hinged plate and the base, and a plurality of suction cups are fixedly connected to the top surface of the hinged plate.

[0009] Preferably, the loading platform is a hollow structure with an open top, a loading plate is rotatably mounted on the top surface of the loading platform, a plurality of through holes are formed on the top surface of the loading plate, a sliding plate is movably connected inside the loading platform, a plurality of mounting columns are fixedly connected to the top surface of the sliding plate and balls are embedded in the top ends of the mounting columns, a flat hydraulic cylinder is fixedly connected to the bottom surface of the loading platform, and the telescopic end of the flat hydraulic cylinder abuts against the bottom surface of the sliding plate.

[0010] Preferably, a fixing rod is fixedly connected to the top surface of the first sliding block, and a passive roller is rotatably mounted on the outer side surface of the fixing rod.

[0011] Preferably, one end of the screw rod passes through the side surface of the center frame and extends into the center frame, and a pinion gear is fixedly sleeved on the circumferential surface of the center frame where the screw rod extends into the center frame.

[0012] Preferably, a first motor is fixedly connected to the interior of the central frame, and a large gear is fixedly sleeved on the output shaft of the first motor. The large gear and the small gear are meshed with each other and their axes are perpendicular.

[0013] Preferably, when the first slider and the second slider slide to the point closest to the supporting mechanism, the rubber roller and the passive roller are tangent to the circumferential side surface of the silicon wafer.

[0014] Preferably, when the front side surface of the stop plate abuts against the buffer pad, the front side surface of the stop plate also abuts against the positioning edge.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1. In the present invention, after the silicon wafer is placed on the loading plate of the carrying mechanism by using a transfer tool such as a manipulator, the first motor is started to drive the screw to rotate. At this time, the first slider and the second slider move toward the center of the circle of the carrying mechanism, so that the center of the circle of the silicon wafer and the center of the circle of the carrying mechanism are in the same vertical direction. Then the second motor is started. At this time, the second motor drives the rubber roller to rotate, and the rubber roller drives the silicon wafer to rotate. As the silicon wafer rotates, when the arc side of the silicon wafer contacts the stop plate, the stop plate will be pushed into the second frame, and at this time the silicon wafer remains in contact with the rubber roller, and as the silicon wafer rotates, its positioning edge contacts the stop plate. At the same time, the stop plate is driven by the torsion spring to rotate toward the center of the silicon wafer, so that the front side of the stop plate abuts against the straight side where the positioning edge is located. At the same time, because the positioning edge is facing the stop plate, the rubber roller no longer contacts the silicon wafer, so that the silicon wafer is no longer driven by the rotation of the rubber roller to continue to rotate. Through the arrangement of the above structure, not only the center of each silicon wafer placed on the supporting mechanism is on the same vertical line as the center of the supporting mechanism, but also the direction of the final positioning edge of each silicon wafer is kept consistent, so that the subsequent robotic arm and other devices can directly place the silicon wafer on the specified position of the wafer carrier when transferring the silicon wafer to the lithography equipment, thereby reducing the time required for multiple positioning and calibration of subsequent lithography steps.

[0017] 2. Secondly, when the stop plate contacts the silicon wafer and is pushed by the silicon wafer to rotate in the direction away from the center of the silicon wafer, the torsion spring stores energy. As the silicon wafer is driven to rotate by the rubber roller, after the positioning edge of the silicon wafer begins to contact the stop plate, the torsion spring releases its stored energy. At this time, the stop plate is driven to rotate in the direction of the center of the silicon wafer, thereby pushing the silicon wafer to continue rotating through the part of the stop plate that contacts the positioning edge. After the positioning edge is completely in contact with the front side of the stop plate, the stop plate stops the silicon wafer. The buffer pad is set to avoid overshoot when the torsion spring drives the stop plate to rotate, which causes the silicon wafer to be squeezed by the stop plate, deformed and broken.

[0018] 3. Finally, after the silicon wafer is placed on the supporting mechanism, the bottom surface of the silicon wafer makes point contact with the ball bearing, thereby reducing the contact area between the silicon wafer and the supporting mechanism when the subsequent centering mechanism and positioning mechanism drive the silicon wafer to slide and rotate, and reducing the probability of the bottom surface of the silicon wafer being scratched. At the same time, after the silicon wafer is positioned by the stop plate, the telescopic rod is started to rotate the hinged plate from a vertical state to a horizontal state. At this time, the suction cup on the top surface of the hinged plate is adsorbed on the bottom surface of the silicon wafer, and the flat hydraulic cylinder is retracted. At this time, the sliding plate slides downward, so that the top end of the ball bearing no longer contacts the bottom surface of the silicon wafer, thereby fixing the silicon wafer on the supporting mechanism, avoiding the silicon wafer from being dislocated due to vibration during the reverse rotation of the screw rod to return the first slider and the second slider, and avoiding the positioning of the silicon wafer from being destroyed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 It is a schematic diagram of the wafer and positioning edge structure of the present invention;

[0021] Figure 3 It is a schematic diagram of the structure of the bearing mechanism of the present invention;

[0022] Figure 4 It is a schematic diagram of the cross-sectional structure of the stage of the present invention;

[0023] Figure 5 This is a schematic diagram of the centering mechanism structure of the present invention;

[0024] Figure 6 It is a schematic diagram of the cross-sectional structure of the center frame and the side frame of the present invention;

[0025] Figure 7 This is a schematic diagram of the structure of the positioning mechanism of the present invention when positioning a wafer;

[0026] Figure 8 It is a schematic diagram of the structure when the positioning mechanism of the present invention does not position the wafer.

[0027] In the figure: 1. silicon wafer; 11. positioning edge; 2. bearing mechanism; 21. base; 22. loading platform; 23. hinged plate; 24. telescopic rod; 25. suction cup; 26. loading plate; 27. through hole; 28. sliding plate; 29. ​​ball bearing; 210. flat hydraulic cylinder; 3. centering mechanism; 31. center frame; 32. side frame; 33. first slide groove; 34. first slider; 35. screw rod; 36. fixing rod; 37. passive roller; 38. small gear; 39. large gear; 310. first motor; 4. positioning mechanism; 41. second slider; 42. second motor; 43. first frame; 44. rubber roller; 45. second frame; 46. stop plate; 47. buffer pad; 48. torsion spring. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] like Figures 1 to 8 As shown, an embodiment of the present invention provides a semiconductor wafer positioning device, including a silicon wafer 1 and a carrying mechanism 2, wherein the silicon wafer 1 is provided with a positioning edge 11, and the carrying mechanism 2 includes a stage 22 for placing the silicon wafer 1, and the stage 22 is fixedly connected to a base 21, and further includes:

[0030] The centering mechanism 3 includes a center frame 31 and a plurality of side frames 32 fixed symmetrically to the sides of the center frame 31. The top surface of the side frame 32 is provided with a first slide groove 33. A positioning mechanism 4 is arranged in the first slide groove 33 of one side frame 32. The first slide grooves 33 of the other side frames 32 are slidably connected with first sliders 34. The side frames 32 are rotatably installed with screw rods 35 to drive the positioning mechanism 4 and the first sliders 34 to gather and disperse;

[0031] The positioning mechanism 4 includes a second slider 41 slidably connected to the first slide groove 33, a second motor 42 is embedded in the second slider 41, the top surface of the second slider 41 is fixedly connected to the first frame 43, the output shaft of the second motor 42 is fixedly sleeved with a rubber roller 44 located in the first frame 43, a second frame 45 is fixedly connected to one side of the first frame 43, a stop plate 46 is rotatably installed inside the first frame 43, a torsion spring 48 is arranged between the stop plate 46 and the first frame 43 to make the stop plate 46 rotate toward the center of the silicon wafer 1, and a buffer pad 47 abutting against the front side of the stop plate 46 is fixedly connected to the side of the second frame 45.

[0032] In the present invention, by setting a centering mechanism 3 and a positioning mechanism 4, after the silicon wafer 1 is placed on the loading plate 26 of the supporting mechanism 2 using a transfer tool such as a manipulator, the first motor 310 is started to drive the screw 35 to rotate, and the first slider 34 and the second slider 41 move toward the center of the circle of the supporting mechanism 2, so that the center of the circle of the silicon wafer 1 and the center of the circle of the supporting mechanism 2 are in the same vertical direction, and then the second motor 42 is started, and the second motor 42 drives the rubber roller 44 to rotate, and the rubber roller 44 drives the silicon wafer 1 to rotate, and as the silicon wafer 1 rotates, when the arc side of the silicon wafer 1 contacts the stop plate 46, the stop plate 46 will be pushed into the second frame 45, and at this time, the silicon wafer 1 remains in contact with the rubber roller 44, and as the silicon wafer 1 rotates, its positioning edge 11 is in contact with the stop plate At the same time, because the positioning edge 11 is facing the stop plate 46, the rubber roller 44 is no longer in contact with the silicon wafer 1, so that the silicon wafer 1 is no longer driven by the rotation of the rubber roller 44 to continue to rotate. Through the arrangement of the above-mentioned structure, not only the center of each silicon wafer 1 placed on the supporting mechanism 2 is on the same vertical line as the center of the supporting mechanism 2, but also the orientation of the final positioning edge 11 of each silicon wafer 1 is kept consistent, so that the subsequent robotic arm and other devices can directly place the silicon wafer 1 on the specified position of the wafer carrier when transferring the silicon wafer 1 to the lithography equipment, thereby reducing the time required for multiple positioning and calibration of subsequent lithography steps.

[0033] Secondly, when the stop plate 46 contacts the silicon wafer 1 and is pushed by the silicon wafer 1 to rotate in the direction away from the center of the silicon wafer 1, the torsion spring 48 stores energy. As the silicon wafer 1 is driven to rotate by the rubber roller 44, after the positioning edge 11 of the silicon wafer 1 begins to contact the stop plate 46, the torsion spring 48 releases its stored energy. At this time, the stop plate 46 is driven to rotate in the direction of the center of the silicon wafer 1, thereby pushing the silicon wafer 1 to continue rotating through the part where the stop plate 46 contacts the positioning edge 11. After the positioning edge 11 is completely in contact with the front side of the stop plate 46, the stop plate 46 stops the silicon wafer 1. The buffer pad 47 is set to avoid overshoot when the torsion spring 48 drives the stop plate 46 to rotate, which causes the silicon wafer 1 to be squeezed by the stop plate 46, deformed and broken.

[0034] Finally, after the silicon wafer 1 is placed on the supporting mechanism 2, the bottom surface of the silicon wafer 1 makes point contact with the ball 29, thereby reducing the contact area between the silicon wafer 1 and the supporting mechanism 2 when the subsequent centering mechanism 3 and the positioning mechanism 4 drive the silicon wafer 1 to slide and rotate, and reducing the probability of the bottom surface of the silicon wafer 1 being scratched. At the same time, after the silicon wafer 1 is positioned by the stop plate 46, the telescopic rod 24 is started to rotate the hinged plate 23 from a vertical state to a horizontal state. At this time, the suction cup 25 on the top surface of the hinged plate 23 is adsorbed on the bottom surface of the silicon wafer 1, and the flat hydraulic cylinder 210 is retracted. At this time, the sliding plate 28 slides downward, so that the top end of the ball 29 no longer contacts the bottom surface of the silicon wafer 1, thereby fixing the silicon wafer 1 on the supporting mechanism 2, avoiding the vibration caused by the reverse rotation of the screw rod 35 to return the first slider 34 and the second slider 41, causing the silicon wafer 1 to be misaligned, and avoiding the positioning of the silicon wafer 1 to be destroyed.

[0035] like Figures 2 to 3 As shown, the bearing mechanism 2 also includes a hinged plate 23 hinged on the side of the loading platform 22, and a plurality of hinged plates 23 are provided. A telescopic rod 24 is hingedly installed between the bottom surface of the hinged plate 23 and the base 21, and a plurality of suction cups 25 are fixedly connected to the top surface of the hinged plate 23.

[0036] After the centering mechanism 3 and the positioning mechanism 4 have positioned the silicon wafer 1, the telescopic rod 24 is driven to extend so that the hinged plate 23 is attached to the bottom surface of the silicon wafer 1. At this time, the suction cup 25 is adsorbed on the bottom surface of the silicon wafer 1, thereby fixing the silicon wafer 1 on the supporting mechanism 2, so that when the subsequent robot arm clamps the silicon wafer 1, the silicon wafer 1 is in the specified position.

[0037] like Figure 3 and Figure 4As shown, the loading platform 22 is a hollow structure with an open top, a loading plate 26 is rotatably mounted on the top surface of the loading platform 22, a plurality of through holes 27 are provided on the top surface of the loading plate 26, a sliding plate 28 is movably connected inside the loading platform 22, a plurality of mounting columns are fixedly connected to the top surface of the sliding plate 28, and balls 29 are embedded in the top ends of the mounting columns, a flat hydraulic cylinder 210 is fixedly connected to the bottom surface of the loading platform 22, and the telescopic end of the flat hydraulic cylinder 210 abuts against the bottom surface of the sliding plate 28.

[0038] The top of the ball 29 is higher than the top surface of the carrier plate 26, so that after the silicon wafer 1 is placed on the supporting mechanism 2, there is multi-point contact between the silicon wafer 1 and the supporting mechanism 2, preventing the silicon wafer 1 from being scratched by particles on the top surface of the carrier plate 26 during the process of being driven to slide and rotate by the centering mechanism 3 and the positioning mechanism 4, thereby ensuring the quality of the silicon wafer 1.

[0039] like Figure 5 and Figure 6 As shown, the top surface of the first slider 34 is fixedly connected to a fixing rod 36, and a passive roller 37 is rotatably mounted on the outer surface of the fixing rod 36. One end of the screw rod 35 passes through the side of the center frame 31 and extends into it. The screw rod 35 extends into the circumferential surface of the center frame 31 and is fixedly sleeved with a pinion 38. The interior of the center frame 31 is fixedly connected to a first motor 310, and the output shaft of the first motor 310 is fixedly sleeved with a large gear 39. The large gear 39 and the small gear 38 are meshed with each other and the axes are perpendicular.

[0040] As the first motor 310 is started, the large gear 39 rotates and drives the lead screw 35 to rotate through the meshing small gears 38. At this time, the first slider 34 and the second slider 41 are driven by the lead screw 35 to move, and the silicon wafer 1 is pushed through the passive roller 37 and the rubber roller 44, so as to center the silicon wafer 1.

[0041] When the first slider 34 and the second slider 41 slide to the closest point to the supporting mechanism 2 , the rubber roller 44 and the passive roller 37 are tangent to the circumferential side surface of the silicon wafer 1 .

[0042] When the rubber roller 44 is tangent to the circumferential side of the silicon wafer 1, when the positioning edge 11 is facing the rubber roller 44, the rubber roller 44 and the silicon wafer 1 are no longer in contact. At this time, even if the rubber roller 44 rotates, it cannot drive the silicon wafer 1 to rotate, thereby ensuring that when the silicon wafer 1 is supported by the stop plate 46, it will no longer be subjected to the force applied by the rubber roller 44, thereby preventing the silicon wafer 1 from being broken due to the force applied by the rubber roller 44 when it is stationary.

[0043] like Figure 1 and Figure 7 As shown, when the front side of the stop plate 46 abuts against the buffer pad 47 , the front side of the stop plate 46 also abuts against the positioning edge 11 .

[0044] Working principle:

[0045] When the device is used to position the silicon wafer 1, the silicon wafer 1 is first placed on the supporting mechanism 2. At this time, the silicon wafer 1 is supported by the ball 29. Then, the first motor 310 is started to drive the screw 35 to rotate through the large gear 39 and the small gear 38, thereby driving the first slider 34 and the second slider 41 to slide toward the center of the supporting mechanism 2. As the first slider 34 and the second slider 41 slide, the silicon wafer 1 is pushed by the rubber roller 44 and the passive roller 37 to be on the same vertical line with the center of the supporting mechanism 2, so that the silicon wafer 1 is centered.

[0046] After the silicon wafer 1 is centered, the second motor 42 is started to drive the rubber roller 44 to rotate. At this time, the rubber roller 44 drives the silicon wafer 1 to rotate. As the silicon wafer 1 rotates, when the positioning edge 11 contacts the stop plate 46, the front side surface of the stop plate 46 abuts against the side surface of the positioning edge 11 of the silicon wafer 1. At this time, the silicon wafer 1 cannot rotate. At the same time, when the positioning edge 11 is facing the stop plate 46, the silicon wafer 1 is no longer in contact with the rubber roller 44, and thus will not continue to be driven to rotate. At this time, the orientation of the positioning edge 11 of the silicon wafer 1 placed on the supporting mechanism 2 is the same each time, so that the silicon wafer 1 is accurately positioned.

[0047] After the silicon wafer 1 is positioned, the telescopic rod 24 is started to make the suction cup 25 on the hinged plate 23 adsorb on the bottom surface of the silicon wafer 1, thereby fixing the silicon wafer 1 on the supporting mechanism 2 to prevent the vibration generated by the first slider 34 and the second slider 41 during the return process from affecting the positioning effect of the silicon wafer 1.

[0048] When the suction cup 25 is adsorbed on the bottom surface of the silicon wafer 1, the flat hydraulic cylinder 210 is driven to retract, so that the ball 29 is immersed in the through hole 27 opened on the carrier plate 26, so that the bottom surface of the silicon wafer 1 is in contact with the top surface of the carrier plate 26, further ensuring the stability of the silicon wafer 1 before being removed.

[0049] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0050] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A semiconductor wafer positioning device, comprising a silicon wafer (1) and a supporting mechanism (2), wherein the silicon wafer (1) is provided with a positioning edge (11), the supporting mechanism (2) comprises a stage (22) for placing the silicon wafer (1), the stage (22) being fixedly connected to a base (21), characterized in that: Also includes: A centering mechanism (3), the centering mechanism (3) comprising a center frame (31) and a plurality of side frames (32) fixed symmetrically to the sides of the center frame (31), a first slide groove (33) being provided on the top surface of the side frame (32), a positioning mechanism (4) being provided in the first slide groove (33) of one of the side frames (32), a first slider (34) being slidably connected in the first slide groove (33) of the other side frames (32), a screw rod (35) being rotatably installed inside the side frame (32) to drive the positioning mechanism (4) and the first slider (34) to gather and disperse; The positioning mechanism (4) includes a second slider (41) slidably connected in the first slide groove (33), a second motor (42) is embedded in the interior of the second slider (41), the top surface of the second slider (41) is fixedly connected to the first frame (43), the output shaft of the second motor (42) is fixedly sleeved with a rubber roller (44) located in the first frame (43), one side of the first frame (43) is fixedly connected to the second frame (45), a stop plate (46) is rotatably installed inside the first frame (43), a torsion spring (48) is arranged between the stop plate (46) and the first frame (43) to make the stop plate (46) rotate toward the center of the silicon wafer (1), and a buffer pad (47) is fixedly connected to the side of the second frame (45) and abuts against the front side of the stop plate (46).

2. A semiconductor wafer positioning device according to claim 1, characterized in that: The bearing mechanism (2) further comprises a hinged plate (23) hinged on the side of the loading platform (22), wherein a plurality of hinged plates (23) are provided, a telescopic rod (24) is hingedly mounted between the bottom surface of the hinged plate (23) and the base (21), and a plurality of suction cups (25) are fixedly connected to the top surface of the hinged plate (23).

3. A semiconductor wafer positioning device according to claim 2, characterized in that: The loading platform (22) is a hollow structure with an open top. A loading plate (26) is rotatably mounted on the top surface of the loading platform (22). A plurality of through holes (27) are provided on the top surface of the loading plate (26). A sliding plate (28) is movably connected inside the loading platform (22). A plurality of mounting columns are fixedly connected to the top surface of the sliding plate (28) and a ball bearing (29) is embedded at the top of the mounting column. A flat hydraulic cylinder (210) is fixedly connected to the bottom surface of the loading platform (22), and the telescopic end of the flat hydraulic cylinder (210) abuts against the bottom surface of the sliding plate (28).

4. A semiconductor wafer positioning device according to claim 3, characterized in that: The top surface of the first sliding block (34) is fixedly connected to a fixing rod (36), and a passive roller (37) is rotatably mounted on the outer side surface of the fixing rod (36).

5. A semiconductor wafer positioning device according to claim 4, characterized in that: One end of the screw rod (35) penetrates through the side surface of the center frame (31) and extends into the center frame (31), and a pinion gear (38) is fixedly sleeved on the circumferential surface of the screw rod (35) extending into the center frame (31).

6. A semiconductor wafer positioning device according to claim 5, characterized in that: A first motor (310) is fixedly connected inside the central frame (31), and a large gear (39) is fixedly sleeved on an output shaft of the first motor (310). The large gear (39) and the small gear (38) are meshed with each other and their axes are perpendicular.

7. A semiconductor wafer positioning device according to claim 6, characterized in that: When the first slider (34) and the second slider (41) slide to the point closest to the bearing mechanism (2), the rubber roller (44) and the passive roller (37) are tangent to the circumferential side surface of the silicon wafer (1).

8. A semiconductor wafer positioning device according to claim 7, characterized in that: When the front side surface of the stop plate (46) abuts against the buffer pad (47), the front side surface of the stop plate (46) also abuts against the positioning edge (11).

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