Wafer polishing equipment

Abstract

The invention provides wafer polishing equipment, which relates to a wafer polishing technology and comprises a bearing table, a wafer polishing device, a wafer polishing device and a wafer polishing device, and the upper surface of the bearing table is coaxially and rotatably provided with a pad; the annular bins rotate around the center shafts of the annular bins and move in the axial direction of the annular bins and the radial direction of the cushion plate, a plurality of air holes are formed in the lower surfaces of the annular bins in a penetrating mode, and lifting rings are coaxially and movably arranged in the annular bins in a matched mode; the multiple suction cups are arranged in the inner ring face of the annular bin, the center axes of the suction cups are all perpendicular to the upper surface of the cushion plate and all arranged above the cushion plate, the suction cups are all movably arranged in the axial direction of the suction cups and the radial direction of the cushion plate, openings are formed in the lower ends of the suction cups, the upper ends of the suction cups are coaxially communicated with air pipes, and the air pipes are used for being communicated with an external air control mechanism; and the liquid injector is arranged above the center of the cushion plate and is used for providing polishing liquid to the center of the cushion plate. According to the invention, the polishing surface of the wafer can be prevented from being damaged during loading and unloading, the polishing effect of the wafer is improved, and the practicability is relatively high.

Description

Technical Field

[0001] This application relates to the field of wafer processing, and more particularly to wafer polishing technology, specifically to a wafer polishing device. Background Technology

[0002] A wafer is a circular silicon substrate used to manufacture semiconductor chips. It is made from high-purity single-crystal silicon through processes such as crystal pulling, slicing, and polishing. Transistors, capacitors, and interconnects of electronic devices are all built on wafers. In the wafer polishing process, chemical mechanical polishing (CMP) is usually used to polish the wafer. This involves a combination of chemical etching and mechanical abrasion to planarize the wafer surface globally, making the wafer surface extremely flat, smooth, and defect-free.

[0003] In existing technologies, a chuck is typically used to fix the unpolished surface of the wafer, and then the polished surface of the wafer comes into contact with polishing slurry spread on a polishing pad. The polishing slurry generally includes chemical reagents and fine abrasives. The chemical reagents soften and oxidize the thin film on the polished surface, while the fine abrasives scrape the polished surface under the rotation of the polishing pad and the chuck itself to achieve polishing. However, when using a loading / unloading device to load or unload the wafer from the chuck, the clamping or suction mechanism of a conventional loading / unloading device inevitably comes into contact with the polished surface of the wafer. This can easily damage the polished surface, and the residual polishing slurry can also contaminate the fixing mechanism used for loading / unloading, thus affecting subsequent loading / unloading processes during polishing and ultimately impacting the polishing effect of the wafer. Summary of the Invention

[0004] To address the aforementioned deficiencies in the prior art, this application provides a wafer polishing device that can avoid damage to the polished surface of the wafer during loading and unloading, and improve the polishing effect of the wafer, thus possessing strong practicality.

[0005] To achieve the above objectives, the present invention employs the following techniques: A wafer polishing apparatus, comprising: The support platform has a pad that rotates coaxially on its upper surface. The annular chamber has multiple central axes perpendicular to the upper surface of the pad and positioned above it. Each annular chamber is rotatable around its own central axis and moves along its own axial direction and the radial direction of the pad. The lower surface of each annular chamber has multiple air holes arranged in a circular array around its own central axis. Each annular chamber has a lifting ring that moves coaxially with it. The lifting rings rotate with the annular chamber, and the contact surfaces between the sides of the lifting rings and the inner wall of the annular chamber are airtight. There are multiple suction cups, each located inside the annular surface of the annular chamber. The central axis of each suction cup is perpendicular to the upper surface of the pad and is located above it. Each suction cup is arranged to move along its own axial direction and the radial direction of the pad. The lower end of the suction cup is set as an opening, and the upper end of the suction cup is coaxially connected to an air pipe, which is used to connect with an external gas control mechanism. The injector, located above the center of the pad, is used to supply polishing fluid to the center of the pad.

[0006] The beneficial effects of this invention are as follows: 1. By separately setting up a suction cup for driving wafer movement and an annular chamber for driving wafer rotation, the edge of the non-polished surface of the wafer can contact the external fixing mechanism during loading and unloading. It will not come into contact with the polished surface of the wafer throughout the entire loading and unloading process, thus avoiding damage to the polished surface of the wafer. In addition, the external fixing mechanism will not be contaminated by polishing fluid, thereby improving the polishing effect.

[0007] 2. By incorporating a spring, the wafer is prevented from deforming and breaking when it transitions from being held in place by a suction cup to being held in place by a ring-shaped container, thus protecting the wafer's integrity. Attached Figure Description

[0008] Figure 1 This is a perspective view of a wafer polishing apparatus according to an embodiment of this application.

[0009] Figure 2 This is a three-dimensional schematic diagram of the drive structure of the annular compartment according to an embodiment of this application. Figure 1 .

[0010] Figure 3 This is a three-dimensional schematic diagram of the drive structure of the annular compartment according to an embodiment of this application. Figure 2 .

[0011] Figure 4 This is a three-dimensional schematic diagram of the driving structure of the suction cup according to an embodiment of this application.

[0012] Figure 5 This is a schematic diagram of the working state of the wafer polishing equipment according to an embodiment of this application. Figure 1 .

[0013] Figure 6 This is a schematic diagram of the working state of the wafer polishing equipment according to an embodiment of this application. Figure 2 .

[0014] Figure 7 This is a schematic diagram of the working state of the wafer polishing equipment according to an embodiment of this application. Figure 3 .

[0015] Figure 8 This is a schematic diagram of the working state of the wafer polishing equipment according to an embodiment of this application. Figure 4.

[0016] Figure 9 This is a schematic diagram of the working state of the wafer polishing equipment according to an embodiment of this application. Figure 5 .

[0017] Markings in the diagram: 1-Bearing platform, 11-Pan, 12-First support rod, 13-Support plate, 14-Second support rod, 2-Annular chamber, 21-Air hole, 22-Lifting ring, 23-Sliding hole, 24-Sliding rod, 25-L-shaped ring, 26-Bearing, 27-First mounting bracket, 28-First electric lead screw, 29-First mating block, 210-First drive rod, 211-Fixing block, 212-Third support rod, 213-Support plate, 214-Rotating motor, 215-Driving gear, 216-Driven gear ring, 217-Fourth support rod, 218-Second mounting bracket 219-Second electric lead screw, 220-Second mating block, 221-Second drive rod, 222-Mounting block, 223-Mounting rod, 224-Roller, 225-Matching ring, 3-Suction cup, 31-Air pipe, 32-Fifth support rod, 33-Third mounting bracket, 34-Third electric lead screw, 35-Third mating block, 36-Fixing plate, 37-Vertical rod, 38-Bearing plate, 39-Drive plate, 310-Miniature cylinder, 311-Drive block, 312-Spring, 313-Air pump, 314-Air delivery hose, 4-Liquid injector, 5-Fixing mechanism, 6-Wafer. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the implementation methods of the present invention will be described in detail below with reference to the accompanying drawings. However, the embodiments described in this invention are only some embodiments of the present invention, and not all embodiments.

[0019] like Figure 1 As shown, this embodiment provides a wafer polishing device, including a support stage 1, an annular chamber 2, a suction cup 3, and a liquid injector 4.

[0020] Specifically, such as Figure 1 As shown, a pad 11 is coaxially rotatably mounted on the upper surface of the support platform 1; in this example, a rotating mechanism for driving the pad 11 to rotate can be provided inside the support platform 1; simultaneously, a pad 11 can be... An annular groove is provided between the bearing platform 1 and the edge of the bearing platform 1 to collect excess polishing liquid flowing out from the edge of the pad 11. An exhaust polishing liquid collection pipe is provided inside the bearing platform 1 to collect excess polishing liquid in the annular groove. The rotating mechanism, the annular groove and the collection pipe are all existing technologies commonly used by those skilled in the art, so they are not shown in the accompanying drawings and will not be described in detail here.

[0021] Specifically, such as Figure 1 and Figure 2 As shown, the annular chamber 2 has multiple annular chambers 2 with their central axes perpendicular to the upper surface of the pad 11 and positioned above it. In this example, there are four annular chambers 2. Each annular chamber 2 is rotatable around its own central axis and moves radially along its own axial direction and the pad 11. Multiple air holes 21 are arranged in a circular array around the lower surface of each annular chamber 2. Lifting rings 22 are coaxially movable within each annular chamber 2, rotating with each annular chamber 2. The contact surfaces between the sides of the lifting rings 22 and the inner wall of the annular chamber 2 are airtight. In this example, The size of the annular chamber 2 is matched to the size of the wafer 6 to be polished. When the unpolished surface of the wafer 6 contacts the lower surface of the annular chamber 2, the unpolished surface of the wafer 6 can completely cover all the pores 21. This increases the distance between the lifting ring 22 and the bottom surface of the annular chamber 2, thereby reducing the air pressure inside the annular chamber 2 below the lifting ring 22. As a result, the wafer 6 is firmly adsorbed onto the lower surface of the annular chamber 2 under atmospheric pressure. Preferably, a sealing ring can be provided at the edge of the pores 21 to more stably adsorb the wafer 6.

[0022] Specifically, such as Figure 1 and Figure 2 As shown, there are multiple suction cups 3 respectively located inside the inner annular surface of the annular chamber 2. In this example, there are four suction cups 3, each located inside the inner annular surface of the annular chamber 2. The central axis of each suction cup 3 is perpendicular to the upper surface of the pad 11 and is located above it. Each suction cup 3 is moved along its own axial direction and the radial direction of the pad 11. The lower end of each suction cup 3 is set as an opening for adsorbing the wafer 6 from the center point of the wafer 6. The upper end of each suction cup 3 is coaxially connected to an air pipe 31, which is used to connect with an external gas control mechanism to create a negative pressure environment inside the suction cup 3, thereby adsorbing the wafer 6.

[0023] Specifically, such as Figure 1 As shown, the liquid injector 4 is located above the center of the pad 11 and is used to provide polishing liquid to the center of the pad 11. The polishing liquid will spread to the edge of the pad 11 due to centrifugal force as the pad 11 rotates, and then come into contact with the polishing surface of the wafer 6 on the annular chamber 2. The specific structure of the liquid injector 4 is prior art known to those skilled in the art, and will not be described in detail here.

[0024] When working, if the above-mentioned preferred solution is adopted, such as Figures 5-9 As shown, the edge of the unpolished surface of wafer 6 is first fixed to the external fixing mechanism 5. The fixing mechanism 5 can adopt the same suction structure as the suction cup 3. The external fixing mechanism 5 drives the wafer 6 to be processed into the area below the annular chamber 2, making the wafer 6 coaxial with the suction cup 3. At this time, the state of the equipment is as follows. Figure 5 As shown; move the fixing mechanism 5 upwards so that the center of the unpolished surface of the wafer 6 contacts the suction cup 3. At this time, the state of the device is as follows. Figure 6As shown; move the suction cup 3 so that it is coaxial with the annular chamber 2. At this time, the state of the device is as follows. Figure 7 As shown; the annular chamber 2 moves downwards. When the lower surface of the annular chamber 2 contacts the unpolished surface of the wafer 6, a sealed space is formed inside the annular chamber 2 below the lifting ring 22. At this time, the annular chamber 2 continues to move downwards, and the suction cup 3 moves synchronously during the movement. The air pressure inside the annular chamber 2 below the lifting ring 22 decreases, and the wafer 6 is adsorbed onto the lower surface of the annular chamber 2. At this time, the state of the device is as follows. Figure 8 As shown; release the suction cup 3 and move it upwards to remove it from the non-polished surface of the wafer 6, then the wafer 6 can be polished. At this time, the state of the equipment is as follows. Figure 9 As shown.

[0025] After polishing, move the suction cup 3 downwards to bring it close to the unpolished surface of the wafer 6. Then move the annular chamber 2 upwards. When the suction cup 3 contacts the unpolished surface of the wafer 6, it will hold the wafer 6 in place. Then, release the drive of the suction cup 3. At this point, the device is in the following state: Figure 8 As shown; continue moving the annular chamber 2 upwards until the wafer 6 is disengaged from the annular chamber 2. At this point, the state of the device is as follows. Figure 7 As shown; the moving suction cup 3 causes the edge of the wafer 6 to extend below the annular chamber 2, and the wafer 6 is held in place by the external fixing mechanism 5. At this time, the state of the device is as follows. Figure 6 As shown; cancel the suction cup 3's attachment to wafer 6, and the device's status at this time is as follows. Figure 5 As shown, the wafer 6 can be removed from the device by moving the fixing mechanism 5.

[0026] Preferred, such as Figure 1 and Figure 2As shown, the upper surface of the annular chamber 2 is perforated with sliding holes 23. In this example, the upper surface of one annular chamber 2 has four sliding holes 23. The upper surface of the lifting ring 22 is provided with sliding rods 24, which are coaxially inserted into the sliding holes 23 and slide in contact with the hole walls of the sliding holes 23. The annular chamber 2 is coaxially provided with L-shaped rings 25 with L-shaped cross sections above it. The horizontal part of the L-shaped rings 25 is connected to the upper end of the sliding rods 24, and the inner side of the vertical part of the L-shaped rings 25 is coaxially connected with bearings 26. The support platform 1 is connected with first support rods 12, and the first support rods 12 are connected to support plates 13. In this example, the support platform 1 is connected with four first support rods 12, and all four first support rods are connected to the same support plate 13. The injector 4 is located on the support plate 13, and the support plate 13 is connected with a number of second support rods 14 matching the number of annular chamber 2. That is, in this example, there are four second support rods 14. Each bearing 26 is connected to a first mounting bracket 27, which is located directly above the bearing 26. Each first mounting bracket 27 has a first electric lead screw 28 arranged radially along the pad 11. The drive shaft of each first electric lead screw 28 is threadedly fitted with a first mating block 29, and the first mating block 29 is slidably limited within the first mounting bracket 27. Each first mating block 29 is connected to a first drive rod 210, which is connected to the inner ring of the bearing 26 directly below it. In this example, one first mating block 29 is connected to two first drive rods 210. With this design, the first electric lead screw 28 drives the first mating block 29 to move, thereby driving the annular chamber 2 to move radially along the pad 11. Simultaneously, by setting the bearing 26 and the mating structure between the sliding hole 23 and the sliding rod 24, the drive of the first electric lead screw 28 on the annular chamber 2 does not affect the movement of the annular chamber 2 along its own axial direction or its rotation around its own central axis.

[0027] Preferred, such as Figure 2 and Figure 3 As shown, each of the first drive rods 210 is provided with a fixing block 211, and each fixing block 211 is connected to a third support rod 212. Each third support rod 212 is connected to a support plate 213. In this example, two third support rods 212 that are matched with the first drive rods 210 by the fixing block 211 and the first drive rod 210 are connected to the same support plate 213. The support plate 213 is provided with a rotating motor 214 whose drive shaft is parallel to the axial direction of the bearing 26. The drive shaft of the rotating motor 214 is coaxially connected to the drive gear 215. The rotating motor 214 is used to drive the drive gear 215 to rotate. The outer side of the vertical part of the L-shaped ring 25 is coaxially connected to a driven gear ring 216. The driven gear ring 216 meshes with the drive gear 215 respectively. This design is used to drive the driven gear ring 216 to rotate through the rotation of the drive gear 215, and then drive the annular chamber 2 to rotate around its own central axis through the bearing 26 and the slide rod 24.

[0028] Preferred, such as Figure 2and Figure 3 As shown, each support plate 213 is connected to a fourth support rod 217, and each fourth support rod 217 is connected to a second mounting bracket 218. Each second mounting bracket 218 has a second electric lead screw 219 arranged along the axial direction of the annular chamber 2. The drive shaft of each second electric lead screw 219 is threadedly fitted with a second mating block 220, and the second mating block 220 is slidably limited within the second mounting bracket 218. Each second mating block 220 is connected to a second drive rod 221. In this example, one second mating block 220 is connected to two second drive rods 221. Each second drive rod 221 is connected to a mounting block 222, and each mounting block 222 has a pair of mounting rods 223. Each pair of mounting rods 223 corresponds to one annular chamber 2 and is arranged parallel to each other along the axial direction of the annular chamber 2. In this example, since one second mating block 220 is connected to two second drive rods 221, the second drive rods 221 are connected to two second drive rods 221. Rod 221, therefore, one annular chamber 2 corresponds to two pairs of mounting rods 223; the mounting rods 223 are respectively arranged radially along the corresponding annular chamber 2, and each mounting rod 223 is coaxially rotatably equipped with a roller 224; the outer surface of the annular chamber 2 is coaxially connected with a mating ring 225, and the upper and lower surfaces of the mating ring 225 respectively contact a pair of rollers 224; with this design, the second electric lead screw 219 is used to drive the second mating block 220 to move, and then drive the annular chamber 2 to move through the cooperation of the rollers 224 and the mating ring 225. During this process, the position of the lifting ring 22 does not actually remain unchanged, but the size of the space of the annular chamber 2 below the lifting ring 22 is controlled by the movement of the annular chamber 2, which simplifies the drive structure and eliminates the need to set a separate drive mechanism for the lifting ring 22; at the same time, the rollers 224 are set here to accommodate the rotation of the annular chamber 2 itself.

[0029] Preferred, such as Figure 1 and Figure 4 As shown, each inner ring of bearing 26 is connected to a fifth support rod 32, and each fifth support rod 32 is connected to a third mounting bracket 33. The third mounting bracket 33 is provided with a third electric screw 34 whose driving direction is parallel to the radial direction of the pad 11. The drive shaft of the third electric screw 34 is threadedly engaged with a third mating block 35, and the third mating block 35 is slidably limited within the third mounting bracket 33. The air pipe 31 moves with the third mating block 35. With this design, the third electric screw 34 is used to drive the third mating block 35 to move, thereby driving the air pipe 31 to move radially along the pad 11.

[0030] Preferred, such as Figure 4As shown, each of the third mating blocks 35 is connected to a fixing plate 36, and each fixing plate 36 has a vertical rod 37 connected to its lower surface. In this example, two vertical rods 37 are connected to the lower end of one fixing plate 36. Each vertical rod 37 is connected to a bearing plate 38. In this example, the two vertical rods 37 connected to one fixing plate 36 are connected to the same bearing plate 38. Each bearing plate 38 has a through hole, and air pipes 31 are slidably inserted through the through hole. Each air pipe 31 has a drive plate 39 vertically connected to its upper end, and the upper end of the air pipe 31 is connected to the upper surface of the drive plate 39. Each fixing plate 36 has a drive direction parallel to the axial direction of the air pipe 31. A miniature cylinder 310 is driven by a drive block 311 connected downwards. The drive block 311 is used to contact the upper surface of the drive plate 39. Springs 312 are coaxially sleeved around the air pipe 31. The lower end of the spring 312 is connected to the upper surface of the suction cup 3, and the upper end of the spring 312 is connected to the lower surface of the support plate 38. When the spring 312 is in its original state, the drive plate 39 is located between the support plate 38 and the drive block 311. The miniature cylinder 310 is used to drive the drive block 311 to move, thereby making the drive block 311 contact the drive plate 39 and press it downwards, so that the air pipe 31 and the suction cup 3 move downwards.

[0031] When using the above preferred solution, such as Figures 5-9 As shown, the edge of the unpolished surface of wafer 6 is first fixed to the external fixing mechanism 5. The external fixing mechanism 5 drives the wafer 6 to be processed into the area below the annular chamber 2, making wafer 6 coaxial with the suction cup 3. At this time, the state of the equipment is as follows. Figure 5 As shown; the fixing mechanism 5 is moved upward so that the center of the unpolished surface of the wafer 6 contacts the suction cup 3. At this time, the spring 312 is slightly compressed, and the wafer 6 is held in place by the suction cup 3. The spring 312 is used to make the contact between the wafer 6 and the suction cup 3 tighter, and also to prevent the fixing mechanism 5 from moving beyond the predetermined stroke, which could cause the wafer 6 to deform and break. At this time, the state of the device is as follows. Figure 6 As shown; move the suction cup 3 so that it is coaxial with the annular chamber 2. At this time, the state of the device is as follows. Figure 7 As shown; the annular chamber 2 moves downwards. When the lower surface of the annular chamber 2 contacts the unpolished surface of the wafer 6, a sealed space is formed inside the annular chamber 2 below the lifting ring 22. If the annular chamber 2 continues to move downwards, the spring 312 stretches, reducing the air pressure inside the annular chamber 2 below the lifting ring 22. The wafer 6 adheres to the lower surface of the annular chamber 2. Here, the spring 312 ensures a tighter bond between the unpolished surface of the wafer 6 and the lower surface of the annular chamber 2, and prevents the annular chamber 2 from moving beyond its predetermined travel distance, which could cause the wafer 6 to deform and break. The state of the device at this time is as follows. Figure 8 As shown; after the suction cup 3 is released, it leaves the non-polished surface of the wafer 6 under the action of the spring 312, allowing the wafer 6 to be polished. The device's state at this time is as follows. Figure 9 As shown.

[0032] After polishing, move the suction cup 3 downwards to bring it close to the unpolished surface of the wafer 6. Then move the annular chamber 2 upwards. When the suction cup 3 contacts the unpolished surface of the wafer 6, it will hold the wafer 6 in place. Then, release the drive of the suction cup 3. At this point, the device is in the following state: Figure 8 As shown; continue moving the annular chamber 2 upwards until the wafer 6 is disengaged from the annular chamber 2. At this point, the state of the device is as follows. Figure 7 As shown; the moving suction cup 3 causes the edge of the wafer 6 to extend below the annular chamber 2, and the wafer 6 is held in place by the external fixing mechanism 5. At this time, the state of the device is as follows. Figure 6 As shown; cancel the suction cup 3's attachment to wafer 6, and the device's status at this time is as follows. Figure 5 As shown, the wafer 6 can be removed from the device by moving the fixing mechanism 5.

[0033] Preferred, such as Figure 2 As shown, each of the first mounting brackets 27 is equipped with an air pump 313. The working end of each air pump 313 is connected to an air supply hose 314. The air supply hose 314 is connected to the upper end of the air pipe 31. The air pump 313 is used to control the air pressure in the suction cup 3 through the air supply hose 314 and the air pipe 31, so that the suction cup 3 can adsorb the wafer 6.

[0034] The above description is only a preferred embodiment of this application and is not intended to limit this application. Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application.

Claims

1. A wafer polishing apparatus characterized by comprising: The utility model relates to a polishing device for polishing wafer, which comprises: a bearing table (1) with a turntable pad (11) on the upper surface; a plurality of annular warehouses (2) arranged above the turntable pad (11) and with the central axis perpendicular to the upper surface of the turntable pad (11), each of the annular warehouses (2) is arranged to rotate around the central axis and to move along the axial direction and the radial direction of the turntable pad (11), the lower surface of each of the annular warehouses (2) is circumferentially arrayed with a plurality of air holes (21) around the central axis, and each of the annular warehouses (2) is coaxially movably connected with a lifting ring (22), the lifting ring (22) rotates with the annular warehouse (2), and the side surface of the lifting ring (22) and the inner wall of the annular warehouse (2) are air-tight; a plurality of suction cups (3) arranged inside the inner ring surface of the annular warehouse (2), the central axis of each of the suction cups (3) is perpendicular to the upper surface of the turntable pad (11) and arranged above the upper surface, each of the suction cups (3) is arranged to move along the axial direction and the radial direction of the turntable pad (11), the lower end of each of the suction cups (3) is provided with an opening, and the upper end is coaxially connected with an air pipe (31) for communication with an external gas control mechanism; an injector (4) arranged above the center of the turntable pad (11) for providing polishing liquid to the center of the turntable pad (11).

2. The wafer polishing apparatus according to claim 1, wherein The upper surface of each of the annular warehouses (2) is provided with a sliding hole (23), the upper surface of each of the lifting rings (22) is provided with a sliding rod (24), the sliding rod (24) is coaxially arranged in the sliding hole (23) and in sliding contact with the hole wall of the sliding hole (23), the upper surface of each of the annular warehouses (2) is coaxially provided with an L-shaped ring (25) with an L-shaped cross section, the horizontal part of the L-shaped ring (25) is connected with the upper end of the sliding rod (24), and the inner side surface of the vertical part of the L-shaped ring (25) is coaxially connected with a bearing (26); the bearing table (1) is connected with a first support rod (12), the first support rod (12) is connected with a support disc (13), the injector (4) is arranged on the support disc (13), the support disc (13) is connected with a second support rod (14) matching in number with the annular warehouses (2), each of the second support rods (14) is connected with a first mounting frame (27) located directly above the bearing (26), each of the first mounting frames (27) is arranged along the radial direction of the turntable pad (11) and provided with a first electric screw (28), the driving shaft of each of the first electric screws (28) is threadedly connected with a first matching block (29), each of the first matching blocks (29) is connected with a first driving rod (210), and each of the first driving rods (210) is connected with the inner ring of the bearing (26) located directly below.

3. The wafer polishing apparatus according to claim 2, wherein Each of the first driving rods (210) is provided with a fixed block (211), each of the fixed blocks (211) is connected with a third support rod (212), each of the third support rods (212) is connected with a support plate (213), the support plate (213) is provided with a rotating motor (214) with the driving shaft parallel to the axial direction of the bearing (26), and the driving shaft of the rotating motor (214) is coaxially connected with a driving gear (215); the outer side surface of the vertical part of the L-shaped ring (25) is coaxially connected with a driven gear ring (216), and the driven gear ring (216) is engaged with the driving gear (215).

4. The wafer polishing apparatus according to claim 3, wherein The support plate (213) is connected with a fourth support rod (217), the fourth support rod (217) is connected with a second mounting frame (218), a second electric screw rod (219) is arranged in the second mounting frame (218) along the axial direction of the annular bin (2), the drive shaft of the second electric screw rod (219) is threadedly connected with a second matching block (220), the second matching block (220) is connected with a second drive rod (221), the second drive rod (221) is connected with a mounting block (222), a pair of mounting rods (223) are arranged on the mounting block (222), each pair of mounting rods (223) correspond to an annular bin (2) and are arranged in parallel along the axial direction of the annular bin (2), and the mounting rods (223) are arranged along the radial direction of the corresponding annular bin (2); the outer side surface of the annular bin (2) is coaxially connected with a matching ring (225), and the upper and lower surfaces of the matching ring (225) are in contact with a pair of rollers (224). The outer side surface of the annular bin (2) is coaxially connected with a matching ring (225), and the upper and lower surfaces of the matching ring (225) are in contact with a pair of rollers (224).

5. The wafer polishing apparatus of claim 2, wherein The inner ring of the bearing (26) is connected with a fifth support rod (32), the fifth support rod (32) is connected with a third mounting frame (33), the third mounting frame (33) is provided with a third electric screw rod (34) whose driving direction is parallel to the radial direction of the tray (11), the driving shaft of the third electric screw rod (34) is threadedly connected with a third matching block (35), and the air pipe (31) moves along with the third matching block (35).

6. The wafer polishing apparatus of claim 5, wherein The third matching block (35) is connected with a fixed plate (36), the lower surface of the fixed plate (36) is connected with a vertical rod (37), the vertical rod (37) is connected with a bearing plate (38), the bearing plate (38) is provided with a through hole, the air pipe (31) is slidably arranged in the through hole, the upper end of the air pipe (31) is perpendicularly connected with a driving plate (39), the upper end of the air pipe (31) is connected to the upper surface of the driving plate (39), the fixed plate (36) is provided with a micro air cylinder (310) whose driving direction is parallel to the axial direction of the air pipe (31), the driving shaft of the micro air cylinder (310) is downwardly connected with a driving block (311), the driving block (311) is used for being in contact with the upper surface of the driving plate (39), the air pipe (31) is coaxially sleeved with a spring (312) on the side, the lower end of the spring (312) is connected with the upper surface of the suction cup (3), the upper end of the spring (312) is connected with the lower surface of the bearing plate (38), and when the spring (312) is in the original state, the driving plate (39) is located between the bearing plate (38) and the driving block (311).

7. The wafer polishing apparatus of claim 2, wherein The first mounting frame (27) is provided with an air pump (313), and the working end of the air pump (313) is connected with a gas conveying hose (314), and the gas conveying hose (314) is connected with the upper end of the air pipe (31).

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