Edge polishing device

Abstract

The utility model discloses an edge polishing device, applies to silicon wafer, to the edge side polishing of silicon wafer, and edge polishing device includes installation component, can lift and rotate, is used for bearing and fixedly waits to polish the silicon wafer, polishing drum subassembly, coaxial sleeve is installed in installation component outside, the inner wall fixed of polishing drum subassembly has polishing tile, drive component, connects and drives polishing drum subassembly to rotate around its axis, and when polishing drum subassembly rotates, the polishing tile of its inner wall pressure contact and rub the edge side of silicon wafer and polish, above -mentioned design through polishing drum subassembly and installation component cooperation, can to the edge side of silicon wafer all around synchronous polishing, second, this polishing drum subassembly eliminates the periodic wear blind area of traditional one -way friction, combines the reverse motion of silicon wafer autorotation and polishing drum subassembly, and the uniformity of the edge side polishing of silicon wafer is improved significantly.

Description

Technical Field

[0001] This utility model relates to the field of silicon wafer polishing technology, and in particular to an edge polishing device. Background Technology

[0002] In semiconductor silicon wafer manufacturing processes, edge polishing is crucial for improving device yield. The burrs and microcracks formed at the edges after silicon wafer cutting can easily trigger the diffusion of lattice defects during subsequent high-temperature processes, leading to stress concentration or impurity deposition. While traditional mechanical polishing can remove macroscopic defects, it is difficult to eliminate submicron-level damage layers and is prone to forming uneven stress zones on the sides.

[0003] Existing edge polishing devices mostly use fixed polishing wheels or linear friction mechanisms. Such structures require repeated adjustments to the silicon wafer clamping angle to cover the entire edge contour, resulting in uneven polishing pressure distribution. The curved areas on the sides are prone to missed polishing or over-polishing. Especially when the silicon wafer thickness continues to be reduced to the hundreds of micrometers, rigid contact is more likely to induce edge chipping. Some rotary polishing mechanisms attempt to improve coverage, but there is still a relative displacement lag between the polishing unit and the silicon wafer, which cannot dynamically adapt to the centrifugal deformation under high-speed rotation.

[0004] Therefore, there is an urgent need for a polishing device that can achieve uniform contact across the entire surface and adaptive pressure control to meet the stringent requirements of advanced processes for the edge quality of silicon wafers. Utility Model Content

[0005] The main purpose of this invention is to provide an edge polishing device to solve the problem of uneven polishing of the edges of silicon wafers.

[0006] To achieve the above objectives, this utility model proposes an edge polishing device applied to a silicon wafer to polish the edge side of the silicon wafer. The edge polishing device includes:

[0007] The mounting components are capable of lifting, lowering, and rotating to support and secure the silicon wafers to be polished.

[0008] A polishing drum assembly is coaxially fitted onto the outside of the mounting assembly, and a polishing tile is fixed to the inner wall of the polishing drum assembly;

[0009] A drive assembly is connected to and drives the polishing drum assembly to rotate about its axis; and

[0010] When the polishing drum assembly rotates, the polishing tiles on its inner wall press against and rub against the edge side of the silicon wafer to polish it.

[0011] The beneficial effects of this utility model are as follows: The edge polishing device, through the coordinated action of the coaxially mounted polishing drum assembly and the liftable and rotatable mounting assembly, enables the polishing tile fixed on the inner wall of the drum to continuously press against the edge side of the silicon wafer under the action of centrifugal force, thereby achieving full circumferential synchronous polishing. Secondly, the polishing drum assembly eliminates the periodic wear blind zone of traditional unidirectional friction. Combined with the silicon wafer's rotation and the reverse movement of the polishing drum assembly, it significantly improves the uniformity of polishing the edge side of the silicon wafer. Furthermore, the closed design of the polishing drum simultaneously constrains the splashing of polishing fluid, reducing the risk of corrosion of precision transmission components. Finally, the overall axially symmetrical layout can avoid local stress concentration, effectively suppressing edge chipping in thin silicon wafer processing, while meeting the dual requirements of high-efficiency polishing and process reliability. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0013] Figure 1 This is a three-dimensional structural diagram of the edge polishing device in this utility model;

[0014] Figure 2 This is a cross-sectional view of the polishing drum assembly (including the drive spindle) in this utility model.

[0015] Label Explanation:

[0016] 1. Installation components; 11. Mounting platform; 12. Waterproof cover; 13. Lifting element; 131. Drive motor; 132. Lifting rod;

[0017] 2. Polishing drum assembly; 21. Polishing drum upper plate; 211. Slide groove; 22. Polishing drum lower plate; 23. Connecting shaft; 24. Centrifugal pushing element; 241. Telescopic block; 2411. Movable groove; 2412. First movable shaft; 2413. Second movable shaft; 242. Center of gravity ball; 243. Connecting rod; 2431. Connecting channel; 25. Enclosure plate;

[0018] 3. Polished tiles;

[0019] 4. Drive assembly; 41. Motor; 42. Synchronous transmission belt; 43. Drive spindle; 431. Polishing fluid channel.

[0020] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, if the word "and / or" appears throughout the text, it means including three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0024] This invention provides an edge polishing device applied to silicon wafers to polish the edge sides of the wafers. The edge polishing device includes a mounting assembly 1, a polishing drum assembly 2, and a drive assembly 4. The mounting assembly 1 is capable of lifting, lowering, and rotating to support and fix the silicon wafer to be polished. The polishing drum assembly 2 is coaxially mounted on the outside of the mounting assembly 1, and polishing tiles 3 are fixed on the inner wall of the polishing drum assembly 2. The drive assembly 4 is connected to and drives the polishing drum assembly 2 to rotate around its axis. When the polishing drum assembly 2 rotates, the polishing tiles 3 on its inner wall press and rub against the edge sides of the silicon wafer to polish it. The above design, through the cooperation of the polishing drum assembly 2 and the mounting assembly 1, enables synchronous polishing of the edge sides of the silicon wafer in the entire circumference. Furthermore, the polishing drum assembly 2 eliminates the periodic wear blind zone of traditional unidirectional friction. Combined with the silicon wafer's rotation and the reverse movement of the polishing drum assembly 2, it significantly improves the uniformity of polishing the edge sides of the silicon wafer.

[0025] In this embodiment, the polishing drum assembly 2 includes an upper polishing drum plate 21, a lower polishing drum plate 22, and multiple centrifugal pushing elements 24. The lower polishing drum plate 22 is an annular plate. The upper polishing drum plate 21 and the lower polishing drum plate 22 are fixedly connected by multiple connecting shafts 23. Obviously, the upper polishing drum plate 21 and the lower polishing drum plate 22 form a hollow cavity that can accommodate the rising mounting assembly 1 to achieve silicon wafer polishing.

[0026] As for the centrifugal pushing element 24, its two ends are slidably connected to the upper plate 21 and the lower plate 22 of the polishing drum, respectively, and the centrifugal pushing element 24 is located between adjacent connecting shafts 23. This arrangement allows the centrifugal pushing element 24 to achieve free displacement along the axial direction of the upper plate 21 of the polishing drum, so that the polishing tile 3 fixed on it can respond in real time to the micro-deformation and position fluctuation of the silicon wafer edge and maintain a constant pressure state. Secondly, the centrifugal pushing element 24 is circumferentially distributed around the axial direction of the upper plate 21 of the polishing drum. Therefore, the centrifugal pushing element 24 is coupled with the centrifugal force of rotation to form a continuous and consistent radial pressure ring on the side of the silicon wafer edge, which completely eliminates the pressure interruption area caused by the fixed pressure block interval distribution. Furthermore, the rigid support frame formed by the connecting shaft 23 and the floating pressure structure of the centrifugal pushing element 24 form a complementary system. While maintaining the overall structural rigidity of the polishing drum assembly 2, it achieves dynamic and balanced loading of polishing pressure, effectively suppresses radial vibration offset under high-speed rotation conditions, and ensures uniform and stable material removal across the entire edge of the silicon wafer.

[0027] In this embodiment, the centrifugal pushing element 24 includes telescopic blocks 241 and a number of center-of-gravity balls 242 adapted to the number of telescopic blocks 241. Slide grooves 211 are respectively provided at corresponding positions on the upper plate 21 and lower plate 22 of the polishing drum. The two ends of the telescopic blocks 241 are slidably inserted into the corresponding slide grooves 211. This design enables the telescopic blocks 241 to slide on the top of the lower plate 22 of the polishing drum. Specifically, a surrounding plate 25 is provided between the edges of the upper plate 21 and lower plate 22 of the polishing drum. The surrounding plate 25 is positioned opposite to the telescopic blocks 241, and a connecting rod 243 is rotatably mounted on the surrounding plate 25. One end of the 3 is connected to the center of gravity ball 242, and the other end passes through the enclosure 25 and abuts against the telescopic block 241. The telescopic block 241 is connected to the polished tile 3. Furthermore, the telescopic block 241 has a recessed movable groove 2411 on the side facing the enclosure 25. A first movable shaft 2412 is installed in the movable groove 2411. A connecting rod 243 is provided at one end of the movable groove 2411 with a connecting channel 2431. The connecting rod 243 is rotatably connected to the first movable shaft 2412 through the connecting channel 2431. A second movable shaft 2413 is provided outside the enclosure 25. The connecting rod 243 is rotatably connected to the second movable shaft 2413.

[0028] The above design fully discloses the dual-pivot lever transmission structure and dynamic adaptation mechanism of the centrifugal pushing element 24. Through the spatial double rotation pair formed by the first movable shaft 2412 in the movable slot 2411 and the second movable shaft 2413 on the outside of the enclosure plate 25, the connecting rod 243 forms a stable lever motion under the action of centrifugal force. The movable slot 2411 on the telescopic block 241 provides radial floating compensation space for the connecting rod 243, eliminating the mechanism jamming caused by silicon wafer deformation during high-speed rotation. The rotational cooperation between the connecting channel 2431 and the first movable shaft 2412 efficiently converts the centrifugal potential energy of the center of gravity ball 242 into the linear thrust of the telescopic block 241, ultimately realizing the stepless adaptive adjustment of polishing pressure with the change of rotation speed.

[0029] Furthermore, the drive assembly 4 includes a motor 41, a synchronous transmission belt 42, and a drive spindle 43. The drive end of the motor 41 is connected to the drive spindle 43 via the synchronous transmission belt 42 to drive the drive spindle 43 to rotate. The end of the drive spindle 43 away from the synchronous transmission belt 42 is fixedly connected to the upper plate 21 of the polishing drum. The above design achieves high-precision speed synchronization and torque transmission by driving the spindle 43 to rotate via the synchronous transmission belt 42 through the motor 41. In addition, the rigid connection between the drive spindle 43 and the upper plate 21 of the polishing drum forms a cantilever support structure, which enables the polishing drum assembly 2 to obtain a stable rotation reference axis, and at the same time provides a basic carrier for the subsequent addition of structures to the drive spindle 43.

[0030] To ensure that the edge of the silicon wafer can be polished, the drive spindle 43 is provided with a polishing fluid channel 431 along the axial direction. The polishing fluid channel 431 is connected to a polishing fluid supply unit. This arrangement utilizes the centrifugal force field generated by the high-speed rotation of the drive spindle 43 to make the polishing fluid diffuse evenly in the radial direction to the contact interface of the silicon wafer edge, and simultaneously complete the abrasive supply, cutting heat conduction and debris flushing. Secondly, this axial through-flow channel design avoids the risk of external pipeline entanglement and ensures a high dynamic matching between fluid supply and rotary polishing motion.

[0031] In this embodiment, an ultrasonic component (not shown) is also provided in the polishing fluid channel 431. The high-frequency vibration is transmitted directly to the polishing interface through coaxial rigid transmission, forming a composite polishing mechanism of "dynamic pressure + high-frequency micro-impact" with the polishing fluid and centrifugal pushing element 24, which effectively solves the problem of brittle fracture at the edge of large silicon wafers.

[0032] In this embodiment, the mounting assembly 1 includes a mounting platform 11, a lifting element 13, a rotating element, and a waterproof cover 12. The driving ends of the lifting element 13 and the rotating element are both connected to the mounting platform 11 and are used to drive the mounting platform 11 to lift and rotate. The waterproof cover 12 is arranged around the mounting platform 11. The above arrangement controls the mounting platform 11 through the dual driving ends of the lifting element 13 and the rotating element, realizing the precise positioning of the silicon wafer on the Z-axis and its rotation around the axis, providing a dynamic posture basis for the full-envelope polishing of the polishing drum assembly 2. The sealing barrier formed by the waterproof cover 12 around the mounting platform 11 prevents the polishing liquid from splashing into the driving mechanism, ensuring the process cleanliness and equipment reliability under high-speed reverse rotation conditions.

[0033] Following the above, the lifting element 13 includes a drive motor 131 and a lifting rod 132. One end of the lifting rod 132 is connected to the mounting platform 11, and the other end is connected to the drive end of the drive motor 131. The drive motor 131 drives the lifting rod 132 to rise and retract, thereby changing the height of the mounting platform 11. In fact, the lifting element 13 and the rotating element (not shown) are both prior art, which should be known to those skilled in the art, and will not be described in detail here.

[0034] It should be noted that in this embodiment, the rotation direction of the polishing drum assembly 2 is opposite to that of the mounting platform 11. In other words, if the polishing drum assembly 2 rotates clockwise, the mounting platform 11 rotates counterclockwise; if the polishing drum assembly 2 rotates counterclockwise, the mounting platform 11 rotates clockwise. Specifically, when the polishing drum assembly 2 and the silicon wafer carried by the mounting platform 11 rotate in opposite directions, an alternating velocity vector is generated at their contact surfaces, causing the polishing tile 3 and the edge of the silicon wafer to form a continuously changing friction trajectory. The relative velocity multiplication effect generated by the counterclockwise rotation significantly improves the cutting efficiency of the abrasive grains on the edge of the silicon wafer, while eliminating the periodic texture accumulation caused by unidirectional polishing, and achieving an atomically smooth surface texture.

[0035] Regarding the operating principle of this edge polishing device, the mounting platform 11 in the mounting assembly 1 lifts and lowers the silicon wafer to be placed in the hollow cavity and drives it to rotate. At the same time, the coaxially mounted polishing drum assembly 2 is driven by the drive spindle 43 to rotate in the opposite direction at high speed. The centrifugal force of the rotation drives the center of gravity ball 242 to swing outward. Through the double movable shaft lever mechanism, the centrifugal potential energy is converted into the radial thrust of the telescopic block 241, which pushes the polishing tile 3 to adaptively press against the edge of the silicon wafer. During this process, the polishing liquid delivered by the polishing liquid channel 431 in the drive spindle 43 evenly covers the polishing interface in the centrifugal field. At the same time, the embedded ultrasonic component transmits high-frequency vibration directly to the polishing interface through coaxial rigid transmission. Together with the polishing liquid and the centrifugal pressure mechanism, a composite polishing mechanism of "dynamic pressure + high-frequency micro-impact" is formed. The above-mentioned structure works together to achieve uniform and damage-free polishing of the entire edge side of the silicon wafer.

[0036] The above are merely optional embodiments of this utility model and do not limit the patent scope of this utility model. All equivalent structural transformations made based on the contents of this utility model specification and drawings under the utility model concept, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. An edge polishing apparatus, applied to a silicon wafer, for polishing the edge sides of the silicon wafer, characterized in that, The edge polishing device includes: The mounting components are capable of lifting, lowering, and rotating to support and secure the silicon wafers to be polished. A polishing drum assembly is coaxially fitted onto the outside of the mounting assembly, and a polishing tile is fixed to the inner wall of the polishing drum assembly; A drive assembly is connected to and drives the polishing drum assembly to rotate about its axis; and When the polishing drum assembly rotates, the polishing tiles on its inner wall press against and rub against the edge side of the silicon wafer to polish it.

2. The edge polishing apparatus according to claim 1, characterized in that, The polishing drum assembly includes an upper polishing drum plate, a lower polishing drum plate, and multiple centrifugal pushing elements; The upper plate of the polishing drum and the lower plate of the polishing drum are fixedly connected by multiple connecting shafts. The two ends of the centrifugal pushing element are slidably connected to the upper plate of the polishing drum and the lower plate of the polishing drum, respectively, and the centrifugal pushing element is located between adjacent connecting shafts.

3. The edge polishing apparatus according to claim 2, characterized in that, The centrifugal pushing element includes telescopic blocks and a center of gravity ball adapted to the number of telescopic blocks; The upper plate and lower plate of the polishing drum are respectively provided with sliding grooves at corresponding positions, and the two ends of the telescopic block are slidably inserted into the corresponding sliding grooves; A surrounding plate is provided between the edge sides of the upper plate and the lower plate of the polishing drum. The surrounding plate is arranged opposite to the telescopic block, and a connecting rod is rotatably provided on the surrounding plate. One end of the connecting rod is connected to the center of gravity ball, and the other end passes through the surrounding plate and abuts against the telescopic block. The telescopic block is connected to the polishing tile.

4. The edge polishing apparatus according to claim 3, characterized in that, The telescopic block has a recessed movable groove on the side facing the enclosure. A first movable shaft is installed in the movable groove. A connecting rod is provided with a connecting channel at one end of the movable groove. The connecting rod is rotatably connected to the first movable shaft through the connecting channel. A second movable shaft is provided on the outside of the enclosure, and the connecting rod is rotatably connected to the second movable shaft.

5. The edge polishing apparatus according to claim 2, characterized in that, The drive assembly includes a motor, a synchronous transmission belt, and a drive spindle. The motor drive end is connected to the drive spindle via the synchronous transmission belt to drive the drive spindle to rotate. The end of the drive spindle furthest from the synchronous transmission belt is fixedly connected to the upper plate of the polishing drum.

6. The edge polishing apparatus according to claim 5, characterized in that, The drive spindle is provided with a polishing fluid channel along the axial direction, and the polishing fluid channel is externally connected to a polishing fluid supply unit.

7. The edge polishing apparatus according to claim 6, characterized in that, An ultrasonic component is also installed in the polishing fluid channel.

8. The edge polishing apparatus according to claim 2, characterized in that, The installation assembly includes a mounting platform, a lifting element, a rotating element, and a waterproof cover. The driving ends of the lifting element and the rotating element are both connected to the mounting platform to drive the mounting platform to lift and rotate. The waterproof cover is arranged around the mounting platform.

9. The edge polishing apparatus according to claim 8, characterized in that, The polishing drum assembly rotates in the opposite direction to the mounting platform.

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