Adjustable silicon wafer table for large size silicon wafer edge polishing and method of adjusting the same

Abstract

An adjustable silicon wafer support platform for large-size silicon wafer edge polishing includes a support table, a center support rod is vertically fixed on the support table, a center support plate is fixedly connected to the top of the center support rod, a moving ring is slidably sleeved on the middle part of the center support rod, a plurality of side support rods are also slidably arranged on the support table, the side support rods are obliquely arranged relative to the support table, and the plurality of side support rods are uniformly distributed around the circumferential direction of the center support rod, the top of the side support rod is fixedly connected with an edge support plate, and the center support plate and all the edge support plates jointly form a support platform for supporting the silicon wafer, and the moving ring can push the side support rod to slide during up-down movement to change the distance between the edge support plate and the center support plate. The actual size of the silicon wafer for edge polishing can be flexibly adjusted according to the need, so that the silicon wafer can be uniformly supported, and the silicon wafer can be prevented from falling due to unstable support when the edge is stressed or being damaged due to uneven stress on the edge.

Description

Technical Field

[0001] This invention relates to the field of silicon wafer manufacturing technology, specifically to an adjustable silicon wafer stage and its adjustment method for edge polishing of large-size silicon wafers. Background Technology

[0002] Silicon wafers are one of the most important raw materials for semiconductor products. During the production process, silicon wafers require surface polishing to eliminate surface defects and ensure the quality of subsequent processed products. The polishing process involves many steps, one of which is edge polishing. In edge polishing, the silicon wafer is placed on a support platform and held in place by negative pressure. A polishing cloth moves around the wafer to polish its edges. In existing technology, the size of the support platform corresponds roughly to the size of the silicon wafer; that is, one size of wafer corresponds to one size of support platform. This means the platform cannot simultaneously meet the processing needs of multiple wafer sizes. The reason is that if a platform used to support small wafers is used to support large wafers, the large wafer only has support in the center, resulting in poor stability and a high risk of detachment or damage. Conversely, if a platform used to support large wafers is used to support small wafers, the polishing cloth cannot easily contact the edges of the small wafer. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides an adjustable silicon wafer support and its adjustment method for edge polishing of large-size silicon wafers. The support can be flexibly adjusted according to the actual size of the silicon wafer to be polished, ensuring uniform support of the silicon wafer and preventing it from falling off due to unstable support or being damaged due to uneven edge force when subjected to force.

[0004] To achieve the above objectives, the specific solution adopted by the present invention is as follows: an adjustable silicon wafer support platform for edge polishing of large-size silicon wafers, comprising a support platform, a central support rod vertically fixedly disposed on the support platform, a central support plate fixedly connected to the top of the central support rod, a movable ring slidably sleeved in the middle of the central support rod, and multiple side support rods slidably disposed on the support platform, the side support rods being inclined relative to the support platform and evenly distributed around the circumference of the central support rod, the top of the side support rods being fixedly connected to edge support plates, the central support plate and all the edge support plates together forming a support platform for supporting silicon wafers, the movable ring being able to push the side support rods to slide during the up and down movement to change the distance between the edge support plates and the central support plate.

[0005] As a further optimization of the aforementioned adjustable silicon wafer support for edge polishing of large-size silicon wafers: the support platform is provided with multiple sliding grooves, and the multiple sliding grooves are evenly distributed along the circumference of the central support rod. The side support rod is fixedly connected with sliders, and the sliders are slidably disposed in the sliding grooves one by one.

[0006] As a further optimization of the aforementioned adjustable wafer stage for polishing the edges of large-size silicon wafers: a spring is connected between the slider and one end of the groove.

[0007] As a further optimization of the aforementioned adjustable silicon wafer stage for edge polishing of large-size silicon wafers: the moving ring is connected to a drive mechanism for driving the moving ring to slide on the central support rod. The drive mechanism includes a linear actuator disposed below the support stage. Two parallel connecting rods are fixedly connected to the lower surface of the support stage. A mounting block is fixedly connected between the two connecting rods. The linear actuator is fixedly disposed on the mounting block.

[0008] As a further optimization of the aforementioned adjustable silicon wafer stage for edge polishing of large-size silicon wafers: a channel is provided in the middle of the central support rod, the channel passes through two oppositely arranged side walls of the central support rod, and the channel is connected to a movable hole that extends to the lower end of the central support rod. A pull rod is slidably arranged in the channel, and the pull rod passes downward through the movable hole and is fixedly connected to the output end of the linear driver. The pull rod is also fixedly connected to at least two connecting rods, and the connecting rods extend out of the channel and are fixedly connected to the inner wall of the moving ring.

[0009] As a further optimization of the aforementioned adjustable silicon wafer stage for edge polishing of large-size silicon wafers: the outer wall of the moving ring is set as a conical surface with the small end facing downwards, and the outer wall of the moving ring can fit against the side support rod. During the process of the linear actuator pulling the pull rod downwards, the pull rod drives the moving ring downwards through the connecting rod and pushes the side support rod towards the central support rod.

[0010] As a further optimization of the aforementioned adjustable silicon wafer stage for polishing the edges of large-size silicon wafers: the upper surface of the edge support plate is provided with at least one first air hole, and the upper surface of the center support plate is provided with at least one second air hole. Both the first and second air holes are connected to air supply pipes, and all air supply pipes are connected to a vacuum pump.

[0011] As a further optimization of the aforementioned adjustable silicon wafer stage for polishing the edges of large-size silicon wafers: the edge support plate has a first flow channel cavity inside, the first air hole is connected to the first flow channel cavity, and the first flow channel cavity is connected to the air supply pipe; the center support plate has a second flow channel cavity inside, the second air hole is connected to the second flow channel cavity, and two adjacent second air holes are separated by a spacer; the second flow channel cavity is connected to the air supply pipe through a suction hole.

[0012] As a further optimization of the aforementioned adjustable silicon wafer stage for polishing the edges of large-size silicon wafers: multiple pipe fixers for fixing the gas supply pipe are fixedly installed on both the central support rod and the side support rod. The pipe fixers include binding straps that can be tied to the central support rod or the side support rod. Each end of the binding strap is fixedly connected to a connecting plate. The two connecting plates are fixedly connected by fasteners. Multiple guide blocks distributed along the length direction are fixedly connected to the binding strap. The guide blocks are provided with positioning grooves for accommodating the gas supply pipe.

[0013] An adjustment method for an adjustable silicon wafer stage used for edge polishing of large-size silicon wafers includes the following steps:

[0014] Determine the dimensions of the silicon wafer;

[0015] The required distance between the edge support plate and the center support plate is calculated based on the size of the silicon wafer.

[0016] The movement of the moving ring is controlled based on the required distance, and the distance between the central support rod and the side support rod is changed during the movement of the moving ring.

[0017] Beneficial effects: When polishing the edges of silicon wafers, the distance between the central support rod and the side support rods is first adjusted according to the actual size of the wafer. This changes the distance between the central support plate and the edge support plate, ensuring that the central and edge support plates provide uniform support for the wafer, improving its stability and preventing damage caused by uneven forces on the wafer edges. The method for adjusting the distance between the central and side support rods is as follows: The moving ring moves up and down. When the moving ring moves downwards, it presses against the side support rod, causing it to move away from the central support rod, thus increasing the distance between them. When the moving ring moves upwards, the side support rod returns to its original position and moves closer to the central support rod, thus decreasing the distance between them. During the movement of the side support rod, the edge support plate moves synchronously, thereby changing the distance between the edge support plate and the center support plate. When the distance between the edge support plate and the center support plate increases, the coverage area of ​​the entire support platform increases, making it suitable for supporting larger silicon wafers. When the distance between the edge support plate and the center support plate decreases, the coverage area of ​​the entire support platform decreases, making it suitable for supporting smaller silicon wafers. This invention is particularly suitable for supporting large-size silicon wafers of 8 inches and 12 inches. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the support platform of the present invention;

[0019] Figure 2 This is a schematic diagram showing the state when the distance between the center support plate and the edge support plate is at its minimum.

[0020] Figure 3 This is a schematic diagram showing the state after the distance between the center support plate and the edge support plate increases;

[0021] Figure 4 This is a structural diagram of a pipe fixing device.

[0022] Figure descriptions: 1-Support platform, 2-Slide groove, 3-Spring, 4-Slider, 5-Side support rod, 6-Edge support plate, 7-First guide cavity, 8-First air hole, 9-Second guide cavity, 10-Second air hole, 11-Spacer bar, 12-Central support plate, 13-Suction hole, 14-Central support rod, 15-Channel, 16-Pull rod, 17-Connecting rod, 18-Moving ring, 19-Output end, 20-Linear driver, 21-Connecting rod, 22-Mounting block, 23-Binding strap, 24-Connecting plate, 25-Fastener, 26-Guide block, 27-Positioning groove. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] like Figures 1 to 4 As shown, an adjustable silicon wafer support for edge polishing of large-size silicon wafers includes a support platform 1. A central support rod 14 is vertically fixed on the support platform 1. A central support plate 12 is fixedly connected to the top of the central support rod 14. A movable ring 18 is slidably sleeved in the middle of the central support rod 14. Multiple side support rods 5 are also slidably arranged on the support platform 1. The side support rods 5 are inclined relative to the support platform 1, and the angle between the side support rods 5 and the support platform 1 is an acute angle. The multiple side support rods 5 are evenly distributed around the circumference of the central support rod 14. The movable ring 18 is located in the space enclosed by all the side support rods 5, that is, the outer wall of the movable ring 18 is in contact with the side support rods 5. An edge support plate 6 is fixedly connected to the top of the side support rods 5. The central support plate 12 and all the edge support plates 6 together form a support platform for supporting silicon wafers. During the up and down movement of the movable ring 18, it can push the side support rods 5 to slide to change the distance between the edge support plates 6 and the central support plate 12.

[0025] When polishing the edges of a silicon wafer, the distance between the central support rod 14 and the side support rod 5 is first adjusted according to the actual size of the wafer. This, in turn, changes the distance between the central support plate 12 and the edge support plate 6, ensuring that the central support plate 12 and the edge support plate 6 can evenly support the wafer, improving its stability and preventing damage caused by uneven forces on the wafer edges. The method for adjusting the distance between the central support rod 14 and the side support rod 5 is as follows: the moving ring 18 is driven to move up and down. When the moving ring 18 moves downward, it presses against the side support rod 5, causing it to move away from the central support rod 14, thus increasing the distance between them. When the moving ring 18 moves upward, the side support rod 5 returns to its original position and moves closer to the central support rod 14, thus decreasing the distance between them. During the movement of the side support rod 5, the edge support plate 6 can move synchronously, thereby changing the distance between the edge support plate 6 and the center support plate 12. When the distance between the edge support plate 6 and the center support plate 12 increases, the coverage area of ​​the entire support platform increases, making it suitable for supporting larger silicon wafers. When the distance between the edge support plate 6 and the center support plate 12 decreases, the coverage area of ​​the entire support platform decreases, making it suitable for supporting smaller silicon wafers. This invention is particularly suitable for supporting large-size silicon wafers of 8 inches and 12 inches.

[0026] The present invention can flexibly adjust the actual size of the silicon wafer that needs to be edge-polished to ensure uniform support of the silicon wafer and prevent the silicon wafer from falling off due to unstable support or being damaged due to uneven edge force when subjected to force.

[0027] The specific connection between the side support rod 5 and the support platform 1 is as follows: Multiple sliding grooves 2 are provided on the support platform 1, and these grooves 2 are evenly distributed along the circumference of the central support rod 14. A slider 4 is fixedly connected to the side support rod 5, and the sliders 4 are slidably positioned in the corresponding grooves 2. Through the cooperation of the grooves 2 and the sliders 4, the movement direction of the side support rod 5 can be restricted, ensuring that the distance between the side support rod 5 and the central support rod 14 can be smoothly increased or decreased during movement.

[0028] To improve efficiency by allowing the side support rod 5 to automatically reset during the upward movement of the moving ring 18 without manual intervention, a spring 3 is connected between the slider 4 and one end of the slide groove 2. When the moving ring 18 moves downward, it pushes the side support rod 5 away from the central support rod 14. During this process, the side support rod 5 moves the slider 4 synchronously, stretching or compressing the spring 3, causing it to store energy. During the upward movement of the moving ring 18, the side support rod 5 is no longer compressed by the moving ring 18, allowing the spring 3 to reset and push or pull the slider 4 back to its original position. This ensures that the side support rod 5 remains in contact with the outer wall of the moving ring 18 and reduces the distance between it and the central support rod 14.

[0029] Furthermore, the moving ring 18 is connected to a driving mechanism for sliding on the central support rod 14. The driving mechanism includes a linear actuator 20 disposed below the support platform 1. Two parallel connecting rods 21 are fixedly connected to the lower surface of the support platform 1, and a mounting block 22 is fixedly connected between the two connecting rods 21. The linear actuator 20 is fixedly disposed on the mounting block 22. The moving ring 18 can be directly pulled or pushed by the linear actuator 20 without manual operation, which can effectively improve production efficiency. Furthermore, the relationship between the size of the silicon wafer and the distance between the central support rod 14 and the side support rod 5 can be predetermined, thereby establishing the relationship between the size of the silicon wafer and the position of the moving ring 18. In actual production, after determining the size of the silicon wafer, the linear actuator 20 can directly drive the moving ring 18 to the preset position, which is simpler and more efficient. In this invention, the linear actuator 20 can be a cylinder, the structure and working principle of which are mature existing technologies and will not be described in detail here.

[0030] The specific connection between the moving ring 18 and the linear actuator 20 is as follows: a channel 15 is provided in the middle of the central support rod 14. The channel 15 passes through two oppositely arranged side walls of the central support rod 14, and the channel 15 is connected to a movable hole that extends to the lower end of the central support rod 14. A pull rod 16 is slidably arranged in the channel 15, and the pull rod 16 passes downward through the movable hole and is fixedly connected to the output end 19 of the linear actuator 20. At least two connecting rods 17 are also fixedly connected to the pull rod 16. The connecting rods 17 extend out of the channel 15 and are fixedly connected to the inner wall of the moving ring 18. When it is necessary to change the position of the moving ring 18, the linear actuator 20 is activated and pushes or pulls the pull rod 16, causing the pull rod 16 to move axially. This allows the moving ring 18 to move via the connecting rods 17. Based on this structure, the pull rod 16 is not affected by the side support rods 5 and the central support rod 14, and the overall structure is simpler.

[0031] To ensure that the moving ring 18 can smoothly push the side support rod 5 to slide along the direction of the slide groove 2, thereby increasing the distance between it and the central support rod 14, the outer wall of the moving ring 18 is set as a tapered surface with the small end facing downward. The outer wall of the moving ring 18 can fit against the side support rod 5. During the process of the linear actuator 20 pulling the pull rod 16 downward, the pull rod 16 drives the moving ring 18 downward through the connecting rod 17 and pushes the side support rod 5 away from the central support rod 14.

[0032] To improve the stability of the silicon wafer on the support platform, at least one first vent 8 is formed on the upper surface of the edge support plate 6, and at least one second vent 10 is formed on the upper surface of the center support plate 12. Both the first vent 8 and the second vent 10 are connected to air supply pipes, and all air supply pipes are connected to a vacuum pump. By providing the first vent 8 and the second vent 10, both the edge support plate 6 and the center support plate 12 can attract and fix the silicon wafer through negative pressure suction, thereby preventing the silicon wafer from moving or rotating. This ensures the stability of the silicon wafer's position, prevents damage to the silicon wafer, and guarantees the edge polishing effect. The specific structure and principle of the air supply pipes and the vacuum pump are existing technologies in this field and will not be discussed further here.

[0033] Furthermore, the edge support plate 6 has a first flow guiding cavity 7 inside, and a first air hole 8 is connected to the first flow guiding cavity 7. The first flow guiding cavity 7 is also connected to the air supply pipe. The center support plate 12 has a second flow guiding cavity 9 inside, and a second air hole 10 is connected to the second flow guiding cavity 9. Adjacent second air holes 10 are separated by a spacer 11. The second flow guiding cavity 9 is connected to the air supply pipe through a suction hole 13. Because the center support plate 12 has a larger area, more second air holes 10 can be provided, which can generate greater suction at the center of the silicon wafer, thereby fully ensuring the stability of the silicon wafer.

[0034] To facilitate the fixation of the gas pipeline and prevent interference between the gas pipeline and the side support rod 5, multiple pipeline fixers are fixedly installed on both the central support rod 14 and the side support rod 5. Each pipeline fixer includes a binding strap 23 that can be tied to either the central support rod 14 or the side support rod 5. A connecting plate 24 is fixedly connected to each end of the binding strap 23, and the two connecting plates 24 are fixedly connected by fasteners 25. Multiple guide blocks 26 distributed along the length of the binding strap 23 are fixedly connected to the binding strap 23, and each guide block 26 has a positioning groove 27 for accommodating the gas pipeline. After the side support rod 5 and the central support rod 14 are installed, the pipeline fixers can be used to fix the gas pipeline to either the central support rod 14 or the side support rod 5, preventing the gas pipeline from moving around and interfering with the side support rod 5. Furthermore, the pipeline fixer has a simple structure and is easy to operate.

[0035] The present invention further provides an adjustment method for an adjustable silicon wafer stage for edge polishing of large-size silicon wafers, comprising S1 to S3.

[0036] S1. Determine the size of the silicon wafer.

[0037] S2. Calculate the required distance between the edge support plate 6 and the center support plate 12 based on the size of the silicon wafer.

[0038] S3. Based on the required distance, control the movement of the moving ring 18. During the movement of the moving ring 18, change the distance between the central support rod 14 and the side support rod 5.

[0039] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An adjustable silicon wafer stage for edge polishing of large-size silicon wafers, characterized in that, The system includes a support platform (1), on which a central support rod (14) is vertically fixed. A central support plate (12) is fixedly connected to the top of the central support rod (14). A moving ring (18) is slidably sleeved in the middle of the central support rod (14). Multiple side support rods (5) are also slidably arranged on the support platform (1). The side support rods (5) are inclined relative to the support platform (1), and the multiple side support rods (5) are evenly distributed around the circumference of the central support rod (14). An edge support plate (6) is fixedly connected to the top of the side support rod (5). The central support plate (12) and all the edge support plates (6) together form a support platform for supporting silicon wafers. During the up-and-down movement of the moving ring (18), the side support rods (5) can be pushed to slide to change the distance between the edge support plates (6) and the central support plate (12). The moving ring (18) is connected to a driving mechanism for driving the moving ring (18) to slide on the central support rod (14). The driving mechanism includes a linear driver (20) disposed below the support platform (1). Two parallel connecting rods (21) are fixedly connected to the lower surface of the support platform (1). A mounting block (22) is fixedly connected between the two connecting rods (21). The linear driver (20) is fixedly disposed on the mounting block (22). The central support rod (14) has a channel (15) in the middle, the channel (15) passes through the two opposite side walls of the central support rod (14), and the channel (15) is connected to an movable hole that passes through to the lower end of the central support rod (14). A pull rod (16) is slidably arranged in the channel (15), and the pull rod (16) passes downward through the movable hole and is fixedly connected to the output end (19) of the linear actuator (20). The pull rod (16) is also fixedly connected to at least two connecting rods (17), and the connecting rods (17) extend out of the channel (15) and are fixedly connected to the inner wall of the moving ring (18). The upper surface of the edge support plate (6) is provided with at least one first air hole (8), and the upper surface of the center support plate (12) is provided with at least one second air hole (10). The first air hole (8) and the second air hole (10) are both connected to air supply pipes, and all air supply pipes are connected to a vacuum pump. The edge support plate (6) has a first flow guide cavity (7) inside, the first air hole (8) is connected to the first flow guide cavity (7), and the first flow guide cavity (7) is connected to the air supply pipe. The center support plate (12) has a second flow guide cavity (9) inside, the second air hole (10) is connected to the second flow guide cavity (9), and two adjacent second air holes (10) are separated by a partition strip (11). The second flow guide cavity (9) is connected to the air supply pipe through a suction hole (13).

2. The adjustable silicon wafer stage for edge polishing of large-size silicon wafers as described in claim 1, characterized in that, The support platform (1) is provided with multiple sliding grooves (2), and the multiple sliding grooves (2) are evenly distributed along the circumference of the central support rod (14). The side support rod (5) is fixedly connected with a slider (4), and the slider (4) is slidably arranged in the sliding groove (2) one by one.

3. An adjustable silicon wafer stage for edge polishing of large-size silicon wafers as described in claim 2, characterized in that, A spring (3) is connected between one end of the slider (4) and the groove (2).

4. The adjustable silicon wafer stage for edge polishing of large-size silicon wafers as described in claim 1, characterized in that, The outer wall of the moving ring (18) is set as a tapered surface with the small end facing downward. The outer wall of the moving ring (18) can fit against the side support rod (5). During the process of the linear actuator (20) pulling the pull rod (16) downward, the pull rod (16) drives the moving ring (18) downward through the connecting rod (17) and pushes the side support rod (5) away from the central support rod (14).

5. An adjustable silicon wafer stage for edge polishing of large-size silicon wafers as described in claim 1, characterized in that, Multiple pipe fixers for fixing the gas transmission pipe are fixedly installed on the central support rod (14) and the side support rod (5). The pipe fixers include binding straps (23) that can be tied to the central support rod (14) or the side support rod (5). Each end of the binding strap (23) is fixedly connected to a connecting plate (24). The two connecting plates (24) are fixedly connected by fasteners (25). Multiple guide blocks (26) distributed along the length direction are fixedly connected to the binding strap (23). The guide blocks (26) are provided with positioning grooves (27) for accommodating the gas transmission pipe.

6. The adjustment method for an adjustable silicon wafer stage for edge polishing of large-size silicon wafers as described in any one of claims 1-5, characterized in that, Includes the following steps: Determine the dimensions of the silicon wafer; The required distance between the edge support plate (6) and the center support plate (12) is calculated based on the size of the silicon wafer; Based on the required distance, the moving ring (18) moves, and during the movement of the moving ring (18), the distance between the central support rod (14) and the side support rod (5) is changed.

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