A polishing device and a polishing method for polishing double-sided curved single-crystal silicon carbide

Abstract

The present invention discloses a polishing device and a polishing method for polishing double-sided curved single-crystal silicon carbide. The polishing device for polishing double-sided curved single-crystal silicon carbide includes: a fixture, two robots and two grinding discs. The fixture is used to fix the double-sided curved single-crystal silicon carbide. Both of the two robots have moving parts. The two grinding discs are respectively connected to the two moving parts one by one. The moving parts drive the grinding discs to move, so as to polish the curved surfaces of the double-sided curved single-crystal silicon carbide. In the technical solution of the present invention, the two moving parts drive the two grinding discs to move respectively, so as to polish the curved surfaces of the double-sided curved single-crystal silicon carbide simultaneously, which can not only meet the grinding conditions for double-sided curved single-crystal silicon carbide, but also polish both sides, improving the grinding efficiency of double-sided curved single-crystal silicon carbide.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon wafer polishing, and particularly relates to a polishing device and a polishing method for polishing double-sided curved single-crystal silicon carbide. Background Art

[0002] Existing double-sided polishing devices for single-crystal silicon carbide are mainly used for batch production of single-crystal silicon carbide substrates. During polishing, the upper grinding disc and the lower grinding disc together grind both sides of the single-crystal silicon carbide substrate. This grinding method can only grind single-crystal silicon carbide substrates with flat surfaces on both sides, and cannot process single-crystal silicon carbide with curved surfaces on both sides. Summary of the Invention

[0003] The main object of the present invention is to provide a polishing device for polishing double-sided curved single-crystal silicon carbide, aiming to solve the problem that existing double-sided polishing devices for single-crystal silicon carbide cannot grind double-sided curved single-crystal silicon carbide.

[0004] To achieve the above object, the polishing device for polishing double-sided curved single-crystal silicon carbide proposed by the present invention includes: a fixture for fixing the double-sided curved single-crystal silicon carbide;

[0005] Two robots, both of which have moving parts;

[0006] Two grinding discs, each of which is respectively connected to one of the two moving parts. The moving part drives the grinding disc to move for grinding the curved surface of the double-sided curved single-crystal silicon carbide.

[0007] 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, enabling the moving part to drive the grinding disc to grind the curved surface of the double-sided curved single-crystal silicon carbide.

[0008] 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 robotic 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 moving part can rotate around the end of the rotating part, and the moving part can rotate around the axis of the rotating part.

[0009] Preferably, the polishing device for polishing double-sided curved single-crystal silicon carbide further includes two driving components respectively connected to the two moving parts. The driving component includes a driving device and an elastic member. The driving device is connected to the grinding disc through the elastic member. When the pressure of the grinding disc is too large, it drives the elastic member to contract and move towards the driving device.

[0010] Preferably, the elastic member is a spring connecting rod, which includes an upper spring shell, a spring, and a lower shell. The upper shell is connected to the 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.

[0011] Preferably, the polishing device for polishing double-sided curved single-crystal silicon carbide further includes two sensors and a controller. Each sensor is disposed between the lower shell and the spring, and the controller controls the grinding disc to move away from the double-sided curved single-crystal silicon carbide according to the first signal of the sensor.

[0012] Preferably, the controller controls the driving device to shut down according to the second signal of the sensor, and the pressure value corresponding to the second signal is greater than the pressure value corresponding to the first signal.

[0013] Preferably, the driving device includes a motor and a gearbox, and the motor drives the elastic member to rotate through the gearbox.

[0014] Preferably, the polishing device for polishing double-sided curved single-crystal silicon carbide further includes a connecting member, which includes a first connecting plate and a second connecting plate connected to each other. The first connecting plate is connected to the moving part, and the driving device is connected to the moving part through the second connecting plate.

[0015] The present invention also provides a polishing method for polishing double-sided curved single-crystal silicon carbide, which uses the polishing device for polishing double-sided curved single-crystal silicon carbide as described above, and includes the following specific steps:

[0016] The moving part of the robot drives the grinding disc to move to polish the two curved surfaces of the double-sided curved single-crystal silicon carbide;

[0017] When the current pressure detected by the sensor is greater than the first preset pressure value, the moving part is controlled to drive the grinding disc to move away from the double-sided curved single-crystal silicon carbide;

[0018] When the current pressure detected by the sensor is greater than the second preset pressure value, and the second preset pressure value is greater than the first preset pressure value, the driving device is controlled to stop.

[0019] The technical solution of the present invention drives the grinding disc to move through the moving part to polish the two curved surfaces of the double-sided curved single-crystal silicon carbide; two moving parts drive the two grinding discs to move respectively to polish the curved surfaces of the double-sided curved single-crystal silicon carbide simultaneously, which can not only meet the grinding conditions of the double-sided curved single-crystal silicon carbide, but also polish both sides, improving the grinding efficiency of the double-sided curved single-crystal silicon carbide. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0021] Figure 1 It is a schematic structural diagram of an embodiment of a polishing device for polishing double-sided curved single-crystal silicon carbide according to the present invention;

[0022] Figure 2 It is a schematic structural diagram of a robot in an embodiment of a polishing device for polishing double-sided curved single-crystal silicon carbide according to the present invention;

[0023] Figure 3 It is a schematic internal structural diagram of a spring connecting rod in an embodiment of a polishing device for polishing double-sided curved single-crystal silicon carbide according to the present invention.

[0024] Explanation of the reference numerals in the drawings:

[0025] 10. Robot; 101. First robotic arm; 102. Second robotic arm; 103. Third robotic arm; 104. Rotating part; 105. Moving part; 106. Base; 121. Flange; 122. First connecting plate; 123. Second connecting plate; 131. Motor; 132. Reducer; 133. Gearbox; 134. Spring connecting rod; 135. Sensor; 136. Transmission bearing; 1341. Spring; 1342. Limiting part; 1343. Upper shell; 1344. Lower shell; 20. Grinding disc; 40. Fixture.

[0026] The realization, functional features and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the drawings. Specific embodiments

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0028] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0029] In addition, the descriptions involving "first", "second", etc. in the present invention are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] Referring to Figure 1 and Figure 2 , the present invention provides a polishing device for polishing double-sided curved single-crystal silicon carbide, including: a fixture 40, two robots 10 and two grinding discs 20. The fixture 40 is used to fix the double-sided curved single-crystal silicon carbide; both of the two robots 10 have a moving part 105; the two grinding discs 20 are respectively connected to the two moving parts 105 one by one, and the moving part 105 drives the grinding disc 20 to move for grinding the curved surface of the double-sided curved single-crystal silicon carbide.

[0031] In this application, the two moving parts 105 respectively drive the two grinding discs 20 to move for simultaneously grinding the two curved surfaces of the double-sided curved single-crystal silicon carbide, which can not only meet the grinding conditions for the double-sided curved single-crystal silicon carbide, but also perform double-sided polishing, improving the grinding efficiency of the double-sided curved single-crystal silicon carbide.

[0032] Specifically, in this embodiment, the two grinding discs 20 are a first grinding disc 20 and a second grinding disc 20, and the axes of the first grinding disc 20 and the second grinding disc 20 coincide, so as to ensure that the upper and lower mirror mechanisms are coaxial during processing; the two robots 10 can be arranged Figure 1 as shown with the mounting surfaces facing the same direction and at different heights, or the mounting surfaces can be in the opposite direction, that is, one robot 10 has the mounting surface facing up and the other robot 10 has the mounting surface facing down. As long as the two curved surfaces of the double-sided curved single-crystal silicon carbide can be polished simultaneously, it belongs to the scope of protection of this application.

[0033] Furthermore, the fixture 40 fixes the double-sided curved single-crystal silicon carbide by means of clamping. Considering the hard and brittle characteristics of single-crystal silicon carbide, the clamping method is the safest. The fixture 40 is fixed to the ground or a mounting plate through an extension rod.

[0034] 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, capable of driving the grinding disc 20 by the moving part 105 to grind the curved surface of the double-sided curved single-crystal silicon carbide.

[0035] Since single-crystal silicon carbide material belongs to hard and brittle materials, and a relatively large polishing pressure will be applied during the processing, it is very easy to produce fragmentation. Therefore, in this embodiment, the moving part 105 with six degrees of freedom drives the grinding disc 20 to polish the curved surface of single-crystal silicon carbide. Since it has multiple degrees of freedom, the grinding disc 20 can polish along the normal of the curved surface of single-crystal silicon carbide during polishing, preventing too much polishing pressure on single-crystal silicon carbide and preventing damage to single-crystal silicon carbide.

[0036] Furthermore, since the two curved surfaces of the double-sided curved single-crystal silicon carbide face two grinding disc directions, the processing of the curved surface is completed by a unit composed of two robots and two electric motors. During processing, the robot moves itself to keep the grinding disc always facing the normal direction of the curved surface.

[0037] 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 robotic 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 moving part 105 can rotate around the end of the rotating part 104, and the moving part 105 can also rotate around the axis of the rotating part 104.

[0038] 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 disc 20 to move.

[0039] Preferably, the robot 10 polishing device for double-sided curved single-crystal silicon carbide further includes two driving components respectively connected to the two moving parts 105. The driving component includes a driving device and an elastic member. The driving device is connected to the grinding disc 20 through the elastic member. When the pressure of the grinding disc 20 is too large, it drives the elastic member to contract and move in the direction close to the driving device.

[0040] Specifically, the driving device includes a motor 131, a gearbox 133, and a transmission bearing 136. The motor 131 is drivingly connected to the gearbox 133 through a speed reducer 132, and the gearbox 133 is drivingly 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. By providing the elastic member, when the pressure on the grinding disc 20 is too high, it can overcome the elastic force of the elastic member to prevent damage to the double-sided curved single-crystal silicon carbide.

[0041] In this embodiment, the motor 131 is a servo motor. The servo motor is connected to the speed reducer 132 through a mounting surface. Through parameter selection and matching, the processing speed range of this device is fixed. The speed reducer 132 is connected to the gearbox 133 through a base surface. The structure of the gearbox 133 determines the motion mode of this device (self-rotation, translational motion, or planetary motion). The gearbox 133 drives to the end through a bearing group.

[0042] As Figure 3 shown, preferably, the elastic member is a spring connecting rod 134. The spring connecting rod 134 includes an upper shell 1343 of the spring 1341, the 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. The upper shell 1343 and the lower shell 1344 move relative to each other when the spring 1341 is subjected to a force.

[0043] Specifically, when the pressure on the grinding disc 20 is too high, the lower shell 1344 overcomes the spring 1341 and drives 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. By providing the spring 1341, damage to the double-sided curved single-crystal silicon carbide can be prevented.

[0044] Preferably, the robot 10 polishing device for double-sided curved single-crystal silicon carbide further includes two sensors 135 and a controller. Each sensor 135 is disposed between the lower shell 1344 and the spring 1341. The controller controls the grinding disc to move away from the double-sided curved single-crystal silicon carbide according to the first signal of the sensor 135.

[0045] 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. When the pressure value exceeds the first preset pressure value, the controller controls the moving portion to drive the grinding disc away from the double-sided curved single-crystal silicon carbide to prevent damage to the double-sided curved single-crystal silicon carbide.

[0046] Preferably, the robotic polishing device for double-sided curved single-crystal silicon carbide further includes a connecting member, 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 driving device is connected to the moving part 105 through the second connecting plate 123.

[0047] Specifically, the connecting member includes a first connecting plate 122 and a second connecting plate 123 that are perpendicularly 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.

[0048] Preferably, the controller controls the driving device to shut down according to the second signal of the sensor, and the pressure value corresponding to the second signal is greater than the pressure value corresponding to the first signal.

[0049] Specifically, when the controller receives a larger pressure value corresponding to the second signal, which has exceeded the pressure value corresponding to the first signal, it controls the driving device to shut down to prevent the grinding disc from damaging the single-crystal silicon carbide.

[0050] The present invention also provides a polishing method for polishing double-sided curved single-crystal silicon carbide, which uses the polishing device for polishing double-sided curved single-crystal silicon carbide as described above. Specifically, it includes the following steps:

[0051] The moving part of the robot drives the grinding disc to move to polish the two curved surfaces of the double-sided curved single-crystal silicon carbide;

[0052] When the current pressure detected by the sensor is greater than the first preset pressure value, it controls the moving part to drive the grinding disc away from the double-sided curved single-crystal silicon carbide;

[0053] When the current pressure detected by the sensor is greater than the second preset pressure value, and the second preset pressure value is greater than the first preset pressure value, it controls the driving device to stop. The sensor 135 real-time feedbacks force monitoring data, which can prevent damage to the double-sided curved single-crystal silicon carbide.

[0054] 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 direction of the grinding disc 20, and the unit composed of the robot 10 and the motor 131 etc. completes the processing of the curved surface. During processing, the robot 10 moves itself to make the grinding disc 20 always face the direction of the curved surface normal. According to the requirements and the removal rate requirements, the parameters of the gearbox are set. During operation, the sensor 135 real-time feedbacks force monitoring data, and the controller controls the moving part to move or turn off the power supply to ensure the safety during the processing.

[0055] The above are only the preferred embodiments of the present invention, and do not thereby limit the patent scope of the present invention. Any equivalent structural transformation made under the concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A polishing device for polishing double-sided curved single-crystal silicon carbide, characterized in that, include: A fixture, the fixture is used to fix the double-sided curved single-crystal silicon carbide; two robots, each of the robots having a moving part; Two grinding discs, the two grinding discs are connected to the two moving parts one by one respectively, and the moving parts drive the grinding discs to move, so as to grind the two curved surfaces of the double-sided curved 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 double-sided curved 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 double-sided curved single-crystal silicon carbide also includes two driving components connected one by one with the two moving parts, the driving components include a driving device and an elastic member, the 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 driving device; 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 driving device, and the lower shell is connected to the grinding disc. The upper shell and the lower shell move relative to each other when the spring is subjected to force. The polishing device for polishing double-sided curved single-crystal silicon carbide also includes two sensors and a controller, each of the sensors is arranged between the lower shell and the spring, and the controller controls the grinding disc to move away from the double-sided curved single-crystal silicon carbide according to the first signal of the sensor; The controller controls the driving device to close according to a second signal from the sensor, and a pressure value corresponding to the second signal is greater than a pressure value corresponding to the first signal.

2. The polishing apparatus for polishing double-sided curved single-crystal silicon carbide according to claim 1, wherein, The driving device includes a motor and a gear box, and the motor drives the elastic member to rotate through the gear box.

3. The polishing device for polishing a double-sided curved single-crystal silicon carbide according to claim 1, characterized in that, The polishing device for polishing double-sided curved single-crystal silicon carbide also includes a connecting member, which includes a first connecting plate and a second connecting plate connected to each other, the first connecting plate is connected to the moving part, and the driving device is connected to the moving part through the second connecting plate.

4. A polishing method for polishing double-sided curved single-crystal silicon carbide, applying the polishing device for polishing double-sided curved single-crystal silicon carbide as described in claim 1, characterized in that, The specific steps include: The moving part of the robot drives the grinding disc to move, so as to grind the two curved surfaces of the double-sided curved single-crystal silicon carbide; The current pressure detected by the sensor is greater than a first preset pressure value, and the moving part is controlled to drive the grinding disc away from the double-sided curved single-crystal silicon carbide; The current pressure detected by the sensor is greater than a second preset pressure value, and the second preset pressure value is greater than the first preset pressure value, and the driving device is controlled to stop.

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