A polishing device for polishing large-caliber single-crystal silicon carbide

Abstract

The present invention discloses a polishing device for polishing large-diameter single-crystal silicon carbide, the polishing device comprising: a fixture, a robot, a grinding disc and a polishing part; the fixture is used to fix the large-diameter single-crystal silicon carbide; the robot has a moving part; the grinding disc is connected to the moving part, and the moving part drives the grinding disc to move, and is used to grind the curved surface of the large-diameter single-crystal silicon carbide; the polishing part is set corresponding to the plane of the large-diameter single-crystal silicon carbide, the polishing part can rotate to grind the plane of the large-diameter single-crystal silicon carbide, and the area of ​​the polishing part is larger than the area of ​​the plane of the large-diameter single-crystal silicon carbide. In the technical solution of the present invention, the robot drives the grinding disc to grind the curved surface of the large-diameter single-crystal silicon carbide, and the polishing part rotates to grind the plane of the large-diameter single-crystal silicon carbide, which can meet the requirements of double-sided polishing; at the same time, the area of ​​the polishing part is larger than the area of ​​the plane of the large-diameter single-crystal silicon carbide, which can meet the grinding conditions of the large-diameter single-crystal silicon carbide.

Description

Technical Field

[0001] The invention relates to the technical field of silicon wafer polishing, and in particular to a polishing device for polishing large-caliber single-crystal silicon carbide. Background Art

[0002] The existing single-crystal silicon carbide double-sided polishing device is mainly used for mass production of single-crystal silicon carbide substrates. During polishing, the upper grinding disc and the lower grinding disc grind the two sides of the single-crystal silicon carbide substrate together. This grinding method can only grind single-crystal silicon carbide substrates with two flat sides. Large-diameter single-crystal silicon carbide is often thicker than the single-crystal silicon carbide substrate. One side of the large-diameter single-crystal silicon carbide is a curved surface, and the other side of the large-diameter single-crystal silicon carbide is a flat surface. The entire large-diameter single-crystal silicon carbide is a flat curved surface. The current single-crystal silicon carbide double-sided polishing device cannot meet the grinding of large-diameter single-crystal silicon carbide. Summary of the invention

[0003] The main purpose of the present invention is to provide a polishing device for polishing large-diameter single-crystal silicon carbide, aiming to solve the problem that the existing single-crystal silicon carbide double-sided polishing device cannot polish large-diameter single-crystal silicon carbide.

[0004] To achieve the above-mentioned purpose, the present invention proposes a polishing device for polishing large-diameter single-crystal silicon carbide, which includes: a fixture, the fixture is used to fix the large-diameter single-crystal silicon carbide;

[0005] A robot having a moving part;

[0006] A grinding disc, wherein the grinding disc is connected to the moving part, and the moving part drives the grinding disc to move, so as to grind the curved surface of the large-diameter single-crystal silicon carbide;

[0007] A polishing portion is provided corresponding to the plane of the large-diameter single-crystal silicon carbide, the polishing portion can be rotated to grind the plane of the large-diameter single-crystal silicon carbide, and the area of ​​the polishing portion is larger than the area of ​​the plane of the large-diameter single-crystal silicon carbide.

[0008] Preferably, the robot includes a rotatable first robotic arm, a second robotic arm, a third robotic arm and a rotating part; the moving part is connected to the rotating part, and the moving part has six degrees of freedom, which enables the moving part to drive the grinding wheel to grind the curved surface of the large-diameter single-crystal silicon carbide.

[0009] Preferably, the first robotic arm can rotate relative to the base around the axis of the base, the second robotic arm can rotate around the end of the first mechanical part, and the third robotic arm can rotate around the end of the second robotic arm; the rotating part can rotate around the axis of the third robotic arm, the movable part can rotate around the end of the rotating part, and the movable part can rotate around the axis of the rotating part.

[0010] Preferably, the polishing device for polishing large-diameter single-crystal silicon carbide also includes a driving assembly connected to the moving part, the driving assembly includes a first driving device and an elastic member, the first driving device is connected to the grinding wheel through the elastic member, and when the pressure of the grinding wheel is too large, the elastic member is driven to contract and move in a direction close to the first driving device.

[0011] Preferably, the elastic member is a spring connecting rod, which includes a spring upper shell, a spring and a lower shell, the upper shell is connected to the first driving device, the lower shell is connected to the grinding disc, and the upper shell and the lower shell move relative to each other when the spring is subjected to force.

[0012] Preferably, the polishing device for polishing large-diameter single-crystal silicon carbide also includes a sensor and a controller, the sensor is arranged between the lower shell and the spring, and the controller controls the first driving device to be closed according to the signal of the sensor.

[0013] Preferably, the polishing device for polishing large-diameter single-crystal silicon carbide also includes a polishing table, the polishing part is a polishing pad, the polishing pad is fixed on the side of the polishing table close to the fixture, and the polishing table can rotate to drive the polishing pad to rotate for polishing.

[0014] Preferably, the polishing device for polishing large-diameter single-crystal silicon carbide also includes a second driving device, and the second driving device includes a second motor and a second gear box, and the second motor drives the polishing table to rotate through the second gear box.

[0015] Preferably, the polishing device for polishing large-diameter single-crystal silicon carbide also includes a polishing liquid recovery system, which includes a recovery pool, a recovery pipeline and a polishing liquid tank. The recovery pool is arranged corresponding to the polishing part, and the recovery pipeline is used to connect the recovery pool and the polishing liquid tank.

[0016] Preferably, the polishing liquid recovery system further comprises a supply pipeline connected to the polishing liquid tank, a water pump is arranged in the polishing liquid tank, and polishing liquid can be supplied to the polishing part through the water pump and the supply pipeline.

[0017] The technical solution of the present invention drives the grinding disc to move through the moving part, which is used to grind the curved surface of the large-diameter single-crystalline silicon carbide, and the polishing part can rotate to grind the flat surface of the large-diameter single-crystalline silicon carbide. The robot drives the grinding disc to grind the curved surface of the large-diameter single-crystalline silicon carbide, and the polishing part rotates to grind the flat surface of the large-diameter single-crystalline silicon carbide, which can meet the requirements of double-sided polishing; at the same time, the area of ​​the polishing part is larger than the area of ​​the flat surface of the large-diameter single-crystalline silicon carbide, which can improve the grinding efficiency of the large-diameter single-crystalline silicon carbide and meet the grinding conditions of the large-diameter single-crystalline silicon carbide. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0019] Figure 1 It is a structural schematic diagram of an embodiment of a polishing device for polishing large-diameter single-crystal silicon carbide according to the present invention;

[0020] Figure 2 It is a schematic structural diagram of a robot in an embodiment of a polishing device for polishing large-diameter single-crystal silicon carbide of the present invention;

[0021] Figure 3 The figure is a schematic diagram of the internal structure of a spring connecting rod in one embodiment of a polishing device for polishing large-diameter single-crystal silicon carbide of the present invention.

[0022] Description of Figure Numbers:

[0023] 10. Robot; 101. First robot arm; 102. Second robot arm; 103. Third robot arm; 104. Rotating part; 105. Moving part; 106. Base; 121. Flange; 122. First connecting plate; 123. Second connecting plate; 131. First motor; 132. Reducer; 133. First gear box; 134. Spring connecting rod; 135. Sensor; 136. Transmission bearing; 1341. Spring; 1342. Limiting part; 1343. Upper shell; 1344. Lower shell; 20. Grinding disc; 30. Polishing pad; 301. Polishing table; 302. Second gear box; 303. Second motor; 40. Fixture; 501. Recovery tank; 502. Supply pipeline; 503. Recovery pipeline; 504. Polishing liquid tank; 505. Third motor.

[0024] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0027] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0028] Reference Figure 1 and Figure 2 The present invention proposes a polishing device for polishing large-diameter single-crystalline silicon carbide, comprising: a fixture 40, a robot 10, a grinding disc 20 and a polishing part; the fixture 40 is used to fix the large-diameter single-crystalline silicon carbide; the robot 10 has a moving part 105; the grinding disc 20 is connected to the moving part 105, and the moving part 105 drives the grinding disc 20 to move, so as to grind the curved surface of the large-diameter single-crystalline silicon carbide; the polishing part is arranged corresponding to the plane of the large-diameter single-crystalline silicon carbide, the polishing part can rotate to grind the plane of the large-diameter single-crystalline silicon carbide, and the area of ​​the polishing part is larger than the area of ​​the plane of the large-diameter single-crystalline silicon carbide.

[0029] In the present application, the moving part 105 drives the grinding disc 20 to move, and is used to grind the curved surface of the large-diameter single-crystalline silicon carbide, and the polishing part can rotate to grind the flat surface of the large-diameter single-crystalline silicon carbide. The robot 10 drives the grinding disc 20 to grind the curved surface of the large-diameter single-crystalline silicon carbide, and the polishing part rotates to grind the flat surface of the large-diameter single-crystalline silicon carbide, which can meet the requirements of double-sided polishing; at the same time, the area of ​​the polishing part is larger than the area of ​​the flat surface of the large-diameter single-crystalline silicon carbide, which can improve the grinding efficiency of the large-diameter single-crystalline silicon carbide and meet the grinding conditions of the large-diameter single-crystalline silicon carbide.

[0030] Furthermore, the rotating polishing part and the moving part 105 drive the grinding disc 20 to polish the upper and lower surfaces of the single-crystal silicon carbide with a flat surface on one side and a curved surface on the other side at the same time, which can improve the polishing efficiency. At the same time, the size of the polishing table 301 is larger than the size of the polished workpiece, for example, the diameter of the large-diameter single-crystal silicon carbide is 300 mm, and the diameter of the polishing part is 350 mm, so the polishing efficiency of the large-diameter single-crystal silicon carbide can be improved.

[0031] Furthermore, the clamp 40 fixes the large-caliber single-crystal silicon carbide by clamping, which is the safest method considering the hard and brittle characteristics of single-crystal silicon carbide. The clamp 40 is fixed to the ground or the mounting plate by an extension rod.

[0032] Preferably, the robot 10 includes a rotatable rotating part 104, a first robotic arm 101, a second robotic arm 102, a third robotic arm 103 and a base 106; the moving part 105 is connected to the rotating part 104, and the moving part 105 has six degrees of freedom, which enables the moving part 105 to drive the grinding wheel 20 to grind the curved surface of the large-diameter single-crystal silicon carbide.

[0033] Since the single crystal silicon carbide material is a hard and brittle material, and a large polishing pressure is applied during the processing, it is easy to break. Therefore, in this embodiment, a moving part 105 with six degrees of freedom is used to drive the grinding disc 20 to polish the curved surface of the single crystal silicon carbide. Due to the multiple degrees of freedom, the grinding disc 20 can polish toward the normal line of the curved surface of the single crystal silicon carbide during polishing, thereby preventing too much polishing pressure from being applied to the single crystal silicon carbide, and thus preventing damage to the single crystal silicon carbide.

[0034] Furthermore, the curved surface of the large-diameter single-crystal silicon carbide faces the grinding wheel 20, and the unit composed of the robot 10 and the first motor 131 completes the processing of the curved surface. During processing, the robot 10 moves itself to make the grinding wheel 20 always face the normal direction of the curved surface.

[0035] Preferably, the first robotic arm 101 can rotate relative to the base 106 around the axis of the base 106, the second robotic arm 102 can rotate around the end of the first mechanical part, and the third robotic arm 103 can rotate around the end of the second robotic arm 102; the rotating part 104 can rotate around the axis of the third robotic arm 103, the movable part 105 can rotate around the end of the rotating part 104, and the movable part 105 can rotate around the axis of the rotating part 104.

[0036] Specifically, since the moving part 105 is connected to the rotating part 104, the rotation of the first robotic arm 101, the second robotic arm 102, the third robotic arm 103, and the rotating part 104 can all drive the moving part 105 to rotate. The moving part 105 itself can rotate around the end of the rotating part 104, and can also rotate around the axis of the rotating part 104. Therefore, the moving part 105 has six degrees of freedom and can drive the grinding wheel 20 to move.

[0037] Preferably, the polishing device for polishing large-diameter single-crystal silicon carbide also includes a driving component connected to the moving part 105, and the driving component includes a first driving device and an elastic member. The first driving device is connected to the grinding wheel 20 through the elastic member. When the pressure of the grinding wheel 20 is too large, the elastic member is driven to contract and move in a direction close to the first driving device.

[0038] Specifically, the first driving device includes a first motor 131, a first gear box 133 and a transmission bearing 136. The first motor 131 is transmission-connected to the first gear box 133 via a reducer 132. The first gear box 133 is transmission-connected to the transmission bearing 136. One end of the elastic member is connected to the rotor of the transmission bearing 136, and the other end of the elastic member is connected to the grinding disc 20. The elastic member is provided so that when the pressure of the grinding disc 20 is too large, the elastic force of the elastic member can be overcome to prevent damage to the large-diameter single-crystal silicon carbide.

[0039] In this embodiment, the first motor 131 is a servo motor, which is connected to the reducer 132 through a mounting surface. Through parameter selection and ratio, the processing speed range of the device is fixed. The reducer 132 is connected to the first gear box 133 through a base surface. The structure of the first gear box 133 determines the movement mode of the device (self-rotation, linear rotation or planetary motion). The first gear box 133 transmits the power to the end through a bearing group.

[0040] like Figure 3As shown, preferably, the elastic member is a spring connecting rod 134, and the spring connecting rod 134 includes a spring 1341, an upper shell 1343, a spring 1341 and a lower shell 1344, the upper shell 1343 is connected to the first driving device, and the lower shell 1344 is connected to the grinding disc 20, and the upper shell 1343 and the lower shell 1344 move relative to each other when the spring 1341 is subjected to force.

[0041] Specifically, when the pressure of the grinding disc 20 is too large, the lower shell 1344 overcomes the spring 1341 to drive the lower shell 1344 to move upward. A limiting portion 1342 is provided on the lower shell 1344, and the spring 1341 is sleeved outside the limiting portion 1342. The provision of the spring 1341 can prevent damage to large-diameter single-crystal silicon carbide.

[0042] Preferably, the polishing device for polishing large-diameter single-crystal silicon carbide also includes a sensor 135 and a controller, wherein the sensor 135 is disposed between the lower shell 1344 and the spring 1341 , and the controller controls the first driving device to be closed according to a signal from the sensor 135 .

[0043] Specifically, the spring 1341 is disposed on the lower shell 1344 and is located between the lower shell 1344 and the bottom of the spring 1341. When the spring 1341 moves, the sensor 135 senses the pressure value, and when the pressure value exceeds the first preset pressure value, the controller controls the first motor 131 to turn off to prevent damage to the large-diameter single-crystal silicon carbide.

[0044] Preferably, the polishing device for polishing large-diameter single-crystal silicon carbide also includes a connecting piece, which includes a first connecting plate 122 and a second connecting plate 123 connected to each other, the first connecting plate 122 is connected to the moving part 105, and the first driving device is connected to the moving part 105 through the second connecting plate 123.

[0045] Specifically, the connecting member includes a first connecting plate 122 and a second connecting plate 123 that are vertically connected to each other. The first connecting plate 122 is connected to the flange 121 , and the flange 121 is connected to the moving part 105 .

[0046] Preferably, the polishing device for polishing large-diameter single-crystal silicon carbide also includes a polishing table 301, the polishing part is a polishing pad 30, the polishing pad 30 is fixed on the polishing table 301 close to the side of the clamp 40, and the polishing table 301 can rotate to drive the polishing pad 30 to rotate for polishing.

[0047] Specifically, the polishing pad 30 is fixed on the polishing table 301 by a pressure-sensitive adhesive, and the polishing pad 30 is in contact with the single crystal silicon carbide workpiece for polishing.

[0048] Preferably, the polishing device for polishing large-diameter single-crystal silicon carbide further includes a second driving device, which includes a second motor 303 and a second gear box 302 , and the second motor 303 drives the polishing table 301 to rotate through the second gear box 302 .

[0049] Specifically, the second motor 303 is a direct drive motor, and the plane of the large-diameter single-crystal silicon carbide faces the polishing pad 30 . The parameters of the second gear box 302 are set according to the plane requirements and the removal rate requirements, thereby determining the movement mode of the polishing table 301 .

[0050] Preferably, the polishing device for polishing large-diameter single-crystal silicon carbide also includes a polishing liquid recovery system, which includes a recovery pool 501 and a recovery pipeline 503. The recovery pool 501 is arranged corresponding to the polishing part, and the recovery pipeline 503 is used to communicate with the recovery pool 501.

[0051] Specifically, a polishing liquid recovery system is provided to recover the polishing liquid, and the recovery pipeline 503 recovers the polishing liquid to a place where it needs to be collected for secondary utilization.

[0052] Preferably, the polishing liquid recovery system further includes a polishing liquid tank 504 , and the recovery pipeline 503 is in communication with the polishing liquid tank 504 .

[0053] Specifically, the recovery pipeline 503 recovers the polishing liquid to the polishing liquid tank 504 for secondary utilization.

[0054] Preferably, the polishing liquid recovery system further comprises a supply pipeline 502 connected to the polishing liquid tank 504 . A water pump is provided in the polishing liquid tank 504 . The polishing liquid can be supplied to the polishing part through the water pump and the supply pipeline 502 .

[0055] Specifically, a water pump is provided in the polishing liquid tank 504, and polishing liquid can be supplied to the polishing part through the water pump and the supply pipeline 502. The polishing recovery system also includes a third motor 505 for driving the water pump to rotate. A filter screen for filtering impurities can be provided in the polishing liquid tank 504, and the filter screen is provided near the inlet of the recovery pipeline 503.

[0056] Considering that the plane polishing is full-diameter processing, in order to ensure the polishing efficiency and the uniformity of the distribution of the polishing liquid, it is necessary to configure a polishing liquid recovery and supply system consisting of a supply pipeline 502, a recovery pipeline 503, a recovery tank 501, a polishing liquid tank 504 and a third motor 505. The polishing liquid in the polishing liquid tank 504 is supplied to the supply pipeline 502 by the third motor 505 and the water pump, and is evenly supplied to the polishing pad 30 with the movement of the polishing table 301. The excess or completed polishing liquid flows into the recovery tank 501 and flows back to the polishing liquid tank 504 through the recovery pipeline 503.

[0057] When the device is working, since the moving part 105 of the robot 10 has 6 degrees of freedom, the curved surface of the single-crystal silicon carbide optical element faces the grinding disc 20, and the unit composed of the robot 10 and the first motor 131 completes the processing of the curved surface. During processing, the robot 10 moves by itself to make the grinding disc 20 always face the normal direction of the curved surface. The plane of the single-crystal silicon carbide optical element faces the polishing pad 30. According to the plane requirements and removal rate requirements, the parameters of the motion gear box 2 are set to determine the movement mode of the polishing table 301. During operation, the sensor 135 feeds back the force monitoring data in real time to ensure the safety of the processing process.

[0058] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A polishing device for polishing large-diameter single-crystal silicon carbide, characterized in that: include: A fixture, the fixture is used to fix the large-caliber single-crystal silicon carbide; A robot having a moving part; A grinding disc, wherein the grinding disc is connected to the moving part, and the moving part drives the grinding disc to move, so as to grind the curved surface of the large-diameter single-crystal silicon carbide; A polishing portion, the polishing portion is arranged corresponding to the plane of the large-diameter single-crystal silicon carbide, the polishing portion can be rotated to grind the plane of the large-diameter single-crystal silicon carbide, and the area of ​​the polishing portion is larger than the area of ​​the plane of the large-diameter single-crystal silicon carbide; The robot comprises a rotatable rotating part, a first mechanical arm, a second mechanical arm, a third mechanical arm and a base; the moving part is connected to the rotating part, and the moving part has six degrees of freedom, so that the moving part can drive the grinding disc to grind the curved surface of the large-diameter single-crystal silicon carbide; The first mechanical arm can rotate relative to the base around the axis of the base, the second mechanical arm can rotate around the end of the first mechanical part, and the third mechanical arm can rotate around the end of the second mechanical arm; the rotating part can rotate around the axis of the third mechanical arm, the moving part can rotate around the end of the rotating part, and the moving part can rotate around the axis of the rotating part; The polishing device for polishing large-diameter single-crystal silicon carbide also includes a driving assembly connected to the moving part, the driving assembly includes a first driving device and an elastic member, the first driving device is connected to the grinding disc through the elastic member, and when the pressure of the grinding disc is too large, the elastic member is driven to contract and move in a direction close to the first driving device; The elastic member is a spring connecting rod, and the spring connecting rod includes a spring upper shell, a spring and a lower shell, the upper shell is connected to the first driving device, the lower shell is connected to the grinding disc, and the upper shell and the lower shell move relative to each other when the spring is subjected to force; The polishing device for polishing large-caliber single-crystal silicon carbide further includes a sensor and a controller, wherein the sensor is disposed between the lower shell and the spring, and the controller controls the first driving device to be closed according to a signal from the sensor; The polishing device for polishing large-diameter single-crystal silicon carbide also includes a polishing table. The polishing part is a polishing pad. The polishing pad is fixed on the side of the polishing table close to the fixture. The polishing table can rotate to drive the polishing pad to rotate for polishing.

2. The polishing device for polishing large-diameter single-crystal silicon carbide according to claim 1, characterized in that: The polishing device for polishing large-diameter single-crystal silicon carbide also includes a second driving device, which includes a second motor and a second gear box. The second motor drives the polishing table to rotate through the second gear box.

3. The polishing device for polishing large-diameter single-crystal silicon carbide according to claim 1, characterized in that: The polishing device for polishing large-diameter single-crystal silicon carbide also includes a polishing liquid recovery system, which includes a recovery pool, a recovery pipeline and a polishing liquid tank. The recovery pool is arranged corresponding to the polishing part, and the recovery pipeline is used to connect the recovery pool and the polishing liquid tank.

4. The polishing device for polishing large-diameter single-crystal silicon carbide according to claim 3, characterized in that: The polishing liquid recovery system also includes a supply pipeline connected to the polishing liquid tank. A water pump is arranged in the polishing liquid tank. The polishing liquid can be supplied to the polishing part through the water pump and the supply pipeline.

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