wafer grinding equipment
By designing a wafer grinding device that combines a grinding disc and a grinding wheel, the problem of edge chipping and fragmentation in the processing of large-size sapphire wafers was solved, achieving efficient and high-precision grinding, eliminating the copper polishing process, and reducing costs and time consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JINHUA BRIGHT ELECTRONIC MATERIALS CO LTD
- Filing Date
- 2022-10-10
- Publication Date
- 2026-07-31
AI Technical Summary
As substrate size increases, the processing difficulty of sapphire wafers increases, and edge chipping and fragmentation problems become more prominent. Existing technologies are unable to perform grinding efficiently and with high precision, and additional copper polishing processes are required, increasing costs and time.
Design a wafer grinding device that uses a combination of a grinding disc and a grinding wheel. The grinding wheel continuously grinds the wafer from the edge to the center. Combined with air nozzle fixation and negative pressure adsorption, it ensures stable grinding force, eliminates the copper polishing process, and improves efficiency and accuracy.
It achieves efficient and high-precision wafer grinding, reduces edge chipping and debris, saves raw materials and time, and meets the processing needs of large-size sapphire wafers.
Smart Images
Figure CN115592559B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of new sapphire materials technology, and in particular to a wafer grinding apparatus. Background Technology
[0002] With the development of modern optics, there are increasing demands for higher performance, lighter weight, and miniaturization of optical components. This necessitates larger substrate sizes to enable the implementation of various patterning schemes. For example, MOCVD is a novel vapor phase epitaxial growth technology developed based on vapor phase epitaxy (VPE). Larger substrates allow for the fabrication of more chips in each MOCVD cycle. The use of large-size sapphire substrates is one of the main factors in reducing LED chip costs. This is primarily because LED chips have edge ineffective regions; therefore, the larger the diameter, the more significant the advantage in chip quantity ratio compared to diameter ratio. For example, a 6-inch substrate has nine times the surface area of a 2-inch substrate, but 10.9 times the number of chips. Thus, the larger the substrate size, the more pronounced the advantage in chip quantity. However, as substrate size increases, the processing difficulty also gradually increases, and problems such as edge chipping and fragmentation become more likely to occur with larger sizes. Summary of the Invention
[0003] In order to ensure wafer thinning efficiency while reducing process steps and lowering the possibility of edge chipping, this application provides a wafer grinding apparatus.
[0004] According to one aspect of the present invention, a wafer polishing apparatus is provided, comprising: a polishing disc, one side of which forms a support plane for the wafer; a first shaft located on one side of the support plane and perpendicular to the support plane, the first shaft being near the edge of the support plane; a polishing wheel connected to the first shaft, the polishing wheel including a polishing surface, the outer ring of the polishing surface extending to the center point of the support plane; and a fixing assembly disposed on the base for fixing the wafer on the support plane.
[0005] By using the wafer grinding device in this technical solution, the wafer is placed on the bearing plane of the grinding disc, and the grinding surface of the grinding wheel continuously grinds the wafer from the edge to the center. This ensures that half of the grinding wheel is in contact with the wafer on the grinding disc, guaranteeing stable grinding force on the wafer edge, low load, and easy thinning. This achieves more efficient and high-precision grinding processing, effectively reducing problems such as wafer chipping and fragmentation that may occur during the processing. After the grinding process of this invention, the copper polishing process that was originally required can be eliminated, saving the required raw materials and time.
[0006] In addition, the wafer polishing apparatus according to this application may also have the following additional technical features:
[0007] In some embodiments of the present invention, the first shaft is located on the side of the grinding wheel away from the grinding disk and is spherically hinged to the center of the grinding wheel; the grinding device further includes a second shaft, which is located on the side of the grinding wheel near the grinding disk and is coaxially connected to the grinding wheel; the upper surface of the grinding disk is provided with an annular track around the bearing plane, and the bottom end of the second shaft is located inside the track and is slidably connected to the track.
[0008] In some embodiments of the present invention, the grinding wheel is rotatably connected to the second shaft on the same axis, the track is an annular groove formed on the upper surface of the grinding disc, the bottom of the groove has a circular arc cross-section, and the bottom end of the second shaft is a flat circular arc head adapted to the bottom of the groove.
[0009] In some embodiments of the present invention, the bottom of the groove is provided with a plurality of annular sliding grooves, the plurality of annular sliding grooves are coaxially arranged with the groove and evenly distributed, and a slider that can be adapted to each of the annular sliding grooves is fixed on the surface of the flat arc head at the bottom end of the second shaft.
[0010] In some embodiments of the present invention, the groove is arranged coaxially with the bearing plane and the inner diameter of the groove is equal to the diameter of the bearing plane.
[0011] In some embodiments of the present invention, the adjustable tilt angle of the grinding surface of the grinding wheel relative to the bearing plane of the grinding disc is -5° to 5°, where the "﹣" sign indicates the tilt direction of the grinding wheel.
[0012] In some embodiments of the present invention, the grinding disc rotates in the opposite direction to the grinding wheel.
[0013] In some embodiments of the present invention, the grinding disc has a through hole that connects the bearing plane and the back side of the grinding disc, and the fixing component includes an air nozzle that is installed in the through hole.
[0014] In some embodiments of the present invention, the upper surface of the air nozzle is flush with the bearing plane of the grinding disc.
[0015] In some embodiments of the present invention, the lower half of the grinding wheel is formed by the grinding wheel material to form the grinding surface, and the grinding wheel mesh number is 300-350 mesh. Attached Figure Description
[0016] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:
[0017] Figure 1 This is a schematic diagram of the overall structure of the wafer polishing apparatus according to an embodiment of this application;
[0018] Figure 2 yes Figure 1 A magnified view of part A in the middle;
[0019] Figure 3 It is a schematic diagram showing the grinding wheel rotating at a set angle outward from the grinding disc;
[0020] Figure 4 It is a schematic diagram showing the grinding wheel rotating at a set angle towards the inside of the grinding disc.
[0021] The reference numerals in the attached diagram represent the following: 1. Grinding disc; 11. Bearing plane; 12. Through hole; 2. First axis; 3. Grinding wheel; 31. Grinding surface; 4. Second axis; 5. Sphere; 6. Ball seat; 7. Groove; 8. Wafer. Detailed Implementation
[0022] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.
[0023] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.
[0024] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.
[0025] The wafer grinding apparatus provided in this application embodiment can be used for grinding large-size sapphire wafers. In addition, the wafer grinding apparatus provided in this application is also suitable for grinding other large-size wafers such as silicon carbide wafers, as well as small-size wafers such as sapphire and silicon carbide wafers. The wafer grinding apparatus provided in this application embodiment will be described below with reference to the accompanying drawings, taking a 6-inch sapphire wafer as an example.
[0026] This application discloses a wafer grinding apparatus. For example... Figure 1 As shown, the wafer polishing apparatus includes a polishing disc 1, a first shaft 2, a polishing wheel 3, and a fixing assembly. The polishing disc 1 forms a bearing plane 11 for the wafer 8 on one side. The first shaft 2 is located on one side of the bearing plane 11 and is perpendicular to the bearing plane 11, and the first shaft 2 is close to the edge of the bearing plane 11. The polishing wheel 3 is connected to the first shaft 2 and includes a polishing surface 31. The outer ring of the polishing surface 31 extends to the center point of the bearing plane 11. The fixing assembly is disposed on a base and is used to fix the wafer 8 on the bearing plane 11.
[0027] By using the wafer grinding apparatus in this technical solution, the wafer 8 is placed on the bearing plane 11 of the grinding disk 1, and the grinding wheel 3, which is of similar size to the wafer 8, is placed on one side of the center of the wafer 8. The grinding wheel 3 and the grinding disk 1 rotate respectively, so that the grinding surface 31 of the grinding wheel 3 continuously grinds the wafer 8 from the edge to the center. During the operation, half of the grinding wheel 3 is in contact with the wafer 8 on the grinding disk 1 for grinding, which ensures that the grinding surface 31 of the grinding wheel 3 has a grinding force on the edge of the wafer 8. This not only ensures stable operation and low load, but also facilitates thinning and achieves more efficient and high-precision grinding processing. It effectively reduces problems such as wafer chipping and fragmentation that may occur during the process. Moreover, the grit of the grinding wheel 3 can be changed to meet the different removal force requirements of the wafer 8. After the grinding process of this invention, the copper polishing process that was originally required can be eliminated accordingly, saving the required raw materials and time.
[0028] Specifically, in this embodiment, the grinding disc 1 and the grinding wheel 3 are driven by different driving devices (not shown), such as gear transmission, belt transmission, chain transmission, worm gear transmission, screw transmission, or transmission method in which the motor output shaft is directly coaxially connected to the grinding disc 1 or the grinding wheel 3. Any structure used to drive the grinding disc 1 or the grinding wheel 3 to rotate is within the protection scope of this invention.
[0029] In some embodiments of the present invention, such as Figure 1 and Figure 2As shown, the first shaft 2 is located on the side of the grinding wheel 3 away from the grinding disc 1 and is ball-jointed at the center of the grinding wheel 3; the grinding device also includes a second shaft 4, which is located on the side of the grinding wheel 3 close to the grinding disc 1 and is coaxially connected to the grinding wheel 3; the upper surface of the grinding disc 1 is provided with an annular track around the bearing plane 11, and the bottom end of the second shaft 4 is located inside the track and is slidably connected to the track.
[0030] The first axis 2 is ball-jointed with the grinding wheel 3, and the bottom end of the second axis 4 is slidably connected to the track on the grinding disk 1. The angle between the grinding surface 31 of the grinding wheel 3 and the bearing plane 11 of the grinding disk 1 can be adjusted. After adjustment, it only needs to be locked to the set angle, for example, to limit free rotation at the ball joint. Then, the grinding wheel 3 is directly driven to rotate by the drive device, so that the grinding surface 31 is at a certain angle relative to the bearing plane 11 to grind the wafer 8, thereby meeting the processing requirements of the wafer 8 with a rounded surface.
[0031] Specifically, the ball joint in this embodiment includes a ball 5 connected to the grinding wheel 3 and a ball seat 6 connected to the end of the first shaft 2. The ball seat 6 has a cavity formed inside for more than half of the ball 5 to be inserted. The ball 5 can rotate freely inside the ball seat 6, thereby realizing the ball joint between the first shaft 2 and the grinding wheel 3.
[0032] In some embodiments of the present invention, such as Figure 3 and Figure 4 As shown, the grinding wheel 3 is coaxially rotatably connected to the second shaft 4. The track is an annular groove 7 formed on the upper surface of the grinding disc 1. The bottom of the groove 7 has a circular arc shape, and the bottom end of the second shaft 4 is a flat, circular arc head that matches the bottom of the groove 7. After the grinding wheel 3 rotates relative to the first shaft 2 by a certain angle through a ball joint, the circular arc design ensures that the bottom end of the second shaft 4 and the annular groove 7 can always be stably connected, guaranteeing the stability of the rotation of the grinding wheel 3 and the circular motion of the grinding wheel 3 around the center of the bearing plane 11.
[0033] Specifically, in other embodiments, the grinding wheel 3 and the second shaft 4 can also be coaxially fixedly connected, and the second shaft 4 and the track can be connected by a rotational connection on the basis of the sliding connection. For example, the second shaft 4 can be divided into two sections, and the two sections can be rotatably connected by bearings.
[0034] In some embodiments of the present invention, such as Figure 3 and Figure 4As shown, the bottom of the groove 7 has multiple annular grooves, which are coaxially arranged and evenly distributed with the annular groove 7. A slider that fits into each annular groove is fixed to the surface of the flat, arc-shaped head at the bottom of the second shaft 4. When the grinding wheel 3 starts working after adjusting the set angle, the first shaft 2 applies pressure to the second shaft 4. The flat, arc-shaped head at the bottom of the second shaft 4 fits against the arc-shaped surface of the groove bottom of the groove 7, and with the mutual locking of the slider and the groove, the grinding wheel 3 is locked at a certain angle. This reduces the additional locking at the ball joint, facilitating angle adjustment and improving efficiency.
[0035] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the annular groove 7 is coaxially arranged with the bearing plane 11, and the inner diameter of the annular groove 7 is equal to the diameter of the bearing plane 11. For wafers 8 with the same dimensions as the bearing plane 11, when placing wafers 8, the edge of wafer 8 coincides with the inner circle of the annular groove 7, thus making it easier and more accurate to place wafer 8 at the center of the bearing surface, improving the accuracy of subsequent grinding. Especially for wafers 8 with rounded surfaces, it can further improve the uniformity of grinding and make the surface of wafer 8 more standard.
[0036] In some embodiments of the present invention, such as Figure 3 and Figure 4 As shown, the adjustable tilt angle of the grinding surface 31 of the grinding wheel 3 relative to the bearing plane 11 of the grinding disc 1 is -5° to 5°, where the "-" sign indicates the tilt direction of the grinding wheel 3. Specifically, the angle between the grinding surface 31 of the grinding wheel 3 and the bearing plane 11 can be set according to the slope requirements of the sapphire wafer 8. Selecting the angle between the grinding surface 31 and the bearing plane 11 as -5° to 5° ensures that the grinding device can process sapphire wafers 8 with more slope requirements while ensuring the grinding effect of the grinding wheel 3 on the sapphire wafer 8.
[0037] In some embodiments of the present invention, the grinding disc 1 and the grinding wheel 3 rotate in opposite directions. This opposite movement of the grinding disc 1 and the grinding wheel 3 further improves grinding efficiency.
[0038] In some embodiments of the present invention, such as Figure 1 As shown, a through hole 12 is provided on the polishing disc 1, which connects the bearing surface 11 and the back side of the polishing disc 1. The fixing component includes an air nozzle, which is installed in the through hole 12. The air nozzle works in conjunction with an external negative pressure device. When the wafer 8 is placed on the polishing disc 1, the air nozzle can stably hold the wafer 8 to perform stable polishing.
[0039] Specifically, in this embodiment, the upper surface of the air nozzle is flush with the bearing plane 11 of the grinding disk 1 to prevent the wafer 8 from being lifted by the air nozzle and tilted at a certain angle, causing uneven grinding and other problems.
[0040] In some embodiments of the present invention, such as Figure 1 As shown, the lower half of the grinding wheel 3 forms the grinding surface 31 with the grinding wheel material, and the grinding wheel 3 has a mesh size of 300-350. Specifically, in this embodiment, the grinding wheel 3 has a mesh size of 320. If the grinding accuracy is not ideal, different mesh sizes of grinding wheels can be used to achieve different degrees of grinding.
[0041] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A wafer grinding apparatus, characterized in that, include: A grinding disc, one side of which forms a support plane for the wafer; A first axis is located on one side of the bearing plane and is perpendicular to the bearing plane, and the first axis is close to the edge of the bearing plane. A grinding wheel is connected to the first shaft, and the grinding wheel includes a grinding surface, the outer ring of which extends to the center point of the bearing plane; A fixing component, disposed on the base, is used to fix the wafer on the bearing plane; The first shaft is located on the side of the grinding wheel away from the grinding disc and is ball-jointed at the center of the grinding wheel; The grinding device further includes a second shaft, which is located on the side of the grinding wheel near the grinding disc and is coaxially connected to the grinding wheel. The upper surface of the grinding disc is provided with an annular track around the bearing plane, and the bottom end of the second shaft is slidably connected to the track.
2. The wafer grinding apparatus according to claim 1, characterized in that, The grinding wheel is rotatably connected to the second shaft on the same axis. The track is an annular groove formed on the upper surface of the grinding disc. The bottom of the groove has a circular arc shape in cross section. The bottom end of the second shaft is a flat circular arc head that matches the bottom of the groove.
3. The wafer grinding apparatus according to claim 2, characterized in that, The bottom of the groove is provided with multiple annular sliding grooves, which are coaxially arranged and evenly distributed with the groove. A slider that can be adapted to each of the annular sliding grooves is fixed on the surface of the flat arc head at the bottom end of the second shaft.
4. The wafer grinding apparatus according to claim 2, characterized in that, The groove is arranged coaxially with the bearing plane, and the inner diameter of the groove is equal to the diameter of the bearing plane.
5. The wafer polishing apparatus according to any one of claims 1-4, characterized in that, The adjustable tilt angle of the grinding surface of the grinding wheel relative to the bearing plane of the grinding disc is -5° to 5°.
6. The wafer polishing apparatus according to any one of claims 1-4, characterized in that, The grinding disc rotates in the opposite direction to the grinding wheel.
7. The wafer polishing apparatus according to any one of claims 1-4, characterized in that, The grinding disc has a through hole that connects the bearing surface and the back side of the grinding disc. The fixing component includes an air nozzle that is installed in the through hole.
8. The wafer polishing apparatus according to claim 7, characterized in that, The upper surface of the air nozzle is flush with the bearing plane of the grinding disc.
9. The wafer polishing apparatus according to any one of claims 1-4, characterized in that, The lower half of the grinding wheel is made of grinding wheel material to form the grinding surface, and the grinding wheel has a mesh size of 300-350.