Polishing equipment based on silicon carbide crystal

Abstract

The invention relates to the technical field of wafer polishing, and discloses silicon carbide wafer polishing equipment which comprises a workbench, a motor is fixedly installed in the center of the top of the workbench, a rotary disc is fixedly connected to the top of an output shaft of the motor, a plurality of placing plates are arranged above the top of the rotary disc, and polishing wafers are placed between the upper portions of the placing plates. A lifting assembly is arranged on the outer side of the containing plate, a connecting assembly for fixing a polishing wafer to the position above the rotary disc is arranged at the top of the rotary disc, a plurality of grinding wheels are arranged on the outer side of the rotary disc, and adjusting assemblies for driving the grinding wheels to conduct position adjustment are arranged at the bottoms of the grinding wheels. The paraffin block can be in a molten state after being subjected to high temperature, then the hot electrode pipe is controlled to be closed, the paraffin block in the molten state can be rapidly cooled down and is fixedly connected with the bottom of the rotating disc, and therefore the polishing wafer can be driven to rotate when the rotating disc rotates, and the grinding and polishing process is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of wafer polishing, and specifically relates to a polishing device based on silicon carbide crystal. Background Art

[0002] Compared with the first and second generation semiconductors, the third generation semiconductor materials represented by silicon carbide have excellent physical properties such as wide bandgap, high breakdown strength, high thermal conductivity, high saturated electron velocity, high hardness, high elastic modulus, low thermal expansion coefficient, and stable chemical properties. It is the preferred alternative to traditional silicon materials in the field of power electronics and has broad application prospects in communications, automobiles, aviation, aerospace, oil extraction, and national defense.

[0003] Among them, the edge polishing process of silicon carbide wafers is a key step in the manufacturing process of silicon carbide devices. Its quality directly affects the performance and reliability of the device. Especially as silicon carbide semiconductors are a hot industry today, large-size silicon carbide wafers are developing rapidly, and edge polishing technology is particularly important for its production yield.

[0004] Currently, when polishing the edge of a silicon carbide wafer, it is necessary to first fix the silicon carbide wafer on a turntable through an additional clamping device, and then the turntable is rotated to continuously polish the edge of the silicon carbide wafer. Since the surface of the silicon carbide wafer is very fragile, the additional clamping device will cause scratches and indentations on the surface, affecting the subsequent performance of the silicon carbide wafer. In addition, the additional cost and operational complexity brought by the additional clamping device are not conducive to the entire polishing task.

[0005] To this end, the present invention provides a polishing device based on silicon carbide crystal. Summary of the invention

[0006] In order to make up for the deficiencies of the prior art: solve at least one technical problem raised in the background technology.

[0007] The technical solution adopted by the present invention to solve its technical problems is: the polishing equipment based on silicon carbide crystal described in the present invention includes a workbench, a motor is fixedly installed at the top center of the workbench, a turntable is fixedly connected to the top of the motor output shaft, a plurality of placement plates are arranged above the top of the turntable, polishing wafers are placed between the tops of the plurality of placement plates, a lifting assembly is arranged on the outside of the placement plates, a connecting assembly for fixing the polishing wafer above the turntable is arranged on the top of the turntable, a plurality of grinding wheels are arranged on the outside of the turntable, an adjusting assembly for driving the grinding wheels to adjust their positions is arranged at the bottom of the grinding wheels, and a linkage assembly for driving the grinding wheels to rotate is arranged between the motor and the plurality of grinding wheels.

[0008] Preferably, a plurality of heating chambers are fixedly mounted on the top of the turntable, a plurality of thermocouples are fixedly mounted on the outer walls of the plurality of heating chambers, the inner walls of the plurality of heating chambers are filled with solid paraffin blocks, and the thermocouples heat the paraffin blocks inside the heating chambers.

[0009] Preferably, the adjustment component includes multiple slide seats 2, and the multiple slide seats 2 are fixedly installed on the top of the workbench. The inner walls of the multiple grinding wheels are fixedly connected with a rotating rod, and the bottom of the rotating rod is rotatably connected with an inner sliding block 2. The outer wall of each inner sliding block 2 is respectively slidably connected to the inner wall of each slide seat 2 and adapted to each other. A transmission component is provided on one side of each inner sliding block 2, and the transmission component is used to drive the inner sliding block 2 to slide inside the slide seat 2.

[0010] Preferably, multiple slides 1 are fixedly installed on the top of the workbench, slide 1 and slide 2 are exactly the same size, the distance between slide 1 and the motor is consistent with the distance between slide 2 and the motor, the interior of slide 1 is slidably connected with an inner slide block 1, the top of the inner slide block 1 is fixedly connected with an outer expansion plate, and the outer expansion plate is located on the outside of the turntable.

[0011] Preferably, the upper half of the expansion plate is arc-shaped, the lower half of the expansion plate is straight, and the distance between the inner side of the straight portion of the expansion plate and the polishing wafer and the distance between the grinding wheel and the polishing wafer are always the same.

[0012] Preferably, a transmission assembly includes a rack plate 1, one side of the inner sliding block 1 is fixedly connected with an external connecting rod 1, the outer wall of the external connecting rod 1 is fixedly connected to the inner wall of the rack plate 1, the teeth of the rack plate 1 are meshed with the gear 1, the teeth of the gear 1 are meshed with the gear 2, the teeth of the gear 2 are meshed with the rack plate 2, the inner wall of one end of the rack plate 2 is fixedly connected with the external connecting rod 2, one end of the external connecting rod 2 is fixedly connected to one side of the inner sliding block 2, a slide bar groove 1 is provided on the side inner wall of the slide seat 1, the slide bar groove 1 is slidably connected to the outer wall of the external connecting rod 1 and adapt to each other, the side inner wall of the slide seat 2 is provided with a slide bar groove 2, the slide bar groove 2 is slidably connected to the outer wall of the external connecting rod 2 and adapt to each other, the size and number of teeth of the gear 1 and the gear 2 are consistent, the teeth size of the rack plate 1 and the rack plate 2 are the same, the shaft rods of the gear 1 and the gear 2 are rotatably connected with a clamp, and the clamp is fixedly installed on the top of the workbench.

[0013] Preferably, one side of each inner sliding block is fixedly connected to a moving rod, the moving rod is plugged into the inner wall of the sliding seat, a return spring is arranged on the outside of the moving rod, one end of the return spring is fixedly connected to one side of the inner sliding block, the other end of the return spring is fixedly connected to the inner side of the sliding seat, and one end of each moving rod is fixedly connected to a limiting sleeve.

[0014] Preferably, the linkage assembly includes two base plates, which are fixedly installed on the top of the workbench, and the tops of the two base plates are respectively rotatably connected with a transmission ring 1 and a transmission ring 2, a transmission belt is transmission-connected between the outer walls of the transmission ring 1 and the transmission ring 2, and the inner wall of the transmission belt is transmission-connected with an inner connecting ring, which is fixedly installed on the outer wall of the rotating rod, the outer wall of the motor output shaft is fixedly connected with a driving gear, and the outer walls of the shafts at multiple transmission rings 2 are fixedly connected with driven gears, and the teeth of the driving gear are respectively meshed with the teeth of multiple driven gears.

[0015] Preferably, the lifting assembly includes an outer base, the inner wall of the outer base is slidably connected to an iron block, the bottom of the inner wall of the outer base is fixedly installed with an electromagnet, one side of the iron block is fixedly connected to one side of the placement plate, the bottom of the outer base is fixedly connected to a base, and the bottom of the base is slidably connected to the workbench.

[0016] Preferably, a spring is fixedly connected to the top of the iron block, the spring is plugged into the inner wall of the top surface of the outer seat, a plug-in rod is arranged outside the plug-in rod, and both ends of the plug-in rod are fixedly connected to the spring and the top of the outer seat respectively.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The polishing equipment for silicon carbide crystal described in the present invention, when the polishing wafer falls onto the turntable, it will fall above multiple heating chambers, and the inner walls of the multiple heating chambers are filled with paraffin solid blocks at the same time. The paraffin blocks inside the heating chambers are heated by turning on the thermistors. The paraffin blocks will become molten after being subjected to high temperature, and then the thermistors are controlled to be closed. The paraffin blocks in the molten state will quickly cool down and be fixedly connected to the bottom of the turntable, so that the polishing wafer will be driven to rotate when the turntable rotates, realizing the grinding and polishing process. After polishing is completed, the paraffin blocks are heated again to a molten state to facilitate the removal of the polishing wafer.

[0019] 2. The polishing equipment based on silicon carbide crystal described in the present invention can automatically adjust the position of the grinding wheel according to the outer diameter of the polishing wafer through the adjustment component, and its outer wall can fit tightly against the outer wall of the polishing wafer, so that the grinding wheel can accurately grind the outer wall of the polishing wafer. The grinding wheel can be flexibly adjusted according to the different outer diameters of the polishing wafer, avoiding the errors that may be caused by manual adjustment, thereby improving the processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings.

[0021] Figure 1 It is an overall stereogram of the present invention;

[0022] Figure 2 It is a structural schematic diagram of the workbench in the present invention;

[0023] Figure 3 It is a schematic diagram of the structure of the turntable in the present invention;

[0024] Figure 4 It is a schematic diagram of the structure of the outer expansion plate in the present invention;

[0025] Figure 5 It is a structural schematic diagram of a slide seat in the present invention;

[0026] Figure 6 It is a schematic diagram of the structure of the grinding wheel in the present invention;

[0027] Figure 7 It is a schematic diagram of the structure of the inner slider at two locations in the present invention;

[0028] Figure 8 It is a schematic diagram of the second structure of the slide in the present invention;

[0029] Fig. 9 It is a schematic diagram of the structure of the outer base in the present invention;

[0030] Fig.10 It is a structural schematic diagram of the iron block in the present invention.

[0031] In the figure: 1, workbench; 2, turntable; 3, motor; 4, grinding wheel; 5, heating chamber; 6, thermistor; 7, external expansion plate; 8, inner slide block 1; 9, slide seat 1; 10, inner slide block 2; 11, slide seat 2; 12, external rod 1; 13, rack plate 1; 14, slide bar groove 1; 15, gear 1; 16, gear 2; 17, rack plate 2; 18, clamping piece; 19, moving rod; 20, reset spring ; 21. Limit sleeve; 22. External rod 2; 23. Slide groove 2; 24. Rotating rod; 25. Transmission ring 1; 26. Internal ring; 27. Transmission belt; 28. Transmission ring 2; 29. ​​Driven gear; 30. Base plate; 31. Driving gear; 32. Polishing wafer; 33. External base; 34. Bottom platform; 35. Iron block; 36. Placement plate; 37. Electromagnet; 38. Spring; 39. Connecting rod. DETAILED DESCRIPTION

[0032] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0033] like Figures 1 to 8As shown, the present invention provides a technical solution: a polishing device based on silicon carbide crystal, comprising a workbench 1, a motor 3 is fixedly installed at the top center of the workbench 1, a turntable 2 is fixedly connected to the top of the output shaft of the motor 3, a plurality of placement plates 36 are arranged above the top of the turntable 2, a polishing wafer 32 is placed between the tops of the plurality of placement plates 36, a lifting assembly is arranged on the outer side of the placement plates 36, a connecting assembly for fixing the polishing wafer 32 above the turntable 2 is arranged on the top of the turntable 2, a plurality of grinding wheels 4 are arranged on the outer side of the turntable 2, an adjusting assembly for driving the grinding wheel 4 to adjust the position is arranged at the bottom of the grinding wheel 4, and a linkage assembly for driving the grinding wheel 4 to rotate is arranged between the motor 3 and the plurality of grinding wheels 4.

[0034] During operation: The surface of the silicon carbide wafer is very fragile, and additional clamping devices will cause scratches and indentations on its surface, affecting the subsequent performance of the silicon carbide wafer. Through the embodiment of the present scheme, during specific use, it is adjusted according to the outer diameter of the polishing wafer 32, so that when the polishing wafer 32 to be polished is placed on the placement plate 36, the outer wall of the polishing wafer 32 can just fit to the inner side of the multiple placement plates 36, and the placement plate 36 is lowered by the lifting component until the polishing wafer 32 falls on the top of the turntable 2, and in the process of the placement plate 36 being lowered, the position of the multiple grinding wheels 4 is adjusted by the adjustment component, and the adjustment component can automatically adjust the position of the multiple grinding wheels 4 according to the outer diameter of the polishing wafer 32, so that the multiple grinding wheels 4 can fit on the edge outer wall of the polishing wafer 32 at the same time, and the automatic adjustment ensures the precise fit of the grinding wheel 4 and the edge of the polishing wafer 32, avoiding manual adjustment. The possible errors are reduced, thereby improving the processing accuracy. After the position of the grinding wheel 4 is adjusted, the polishing wafer 32 will fall into the connecting component on the top of the turntable 2 and be fixedly connected to the turntable 2 through the connecting component. Then the motor 3 is started, and its output shaft will drive the multiple grinding wheels 4 to rotate through the linkage component. The grinding wheels 4 polish the edges of the polishing wafer 32 when rotating, and the motor 3 will also drive the polishing wafer 32 to rotate through the turntable 2 when starting, so that the multiple grinding wheels 4 can polish all the edges of the polishing wafer 32 at the same time. After the polishing is completed, the fixing of the polishing wafer 32 by the connecting component is cancelled, and the polishing wafer 32 is taken out. Through the above embodiment, the connecting component can fix the polishing wafer 32 above the turntable 2, and while achieving comprehensive polishing of the edges, it can avoid scratches and indentations on the surface of the polishing wafer 32 caused by fixing by an additional clamping device.

[0035] like Figures 2 to 3 As shown, a plurality of heating chambers 5 are fixedly installed on the top of the turntable 2, a plurality of thermocouples 6 are fixedly installed on the outer walls of the plurality of heating chambers 5, and the inner walls of the plurality of heating chambers 5 are filled with solid paraffin blocks, and the thermocouples 6 heat the paraffin blocks inside the heating chambers 5.

[0036] During operation: when the polishing chip 32 falls onto the turntable 2, it will fall above multiple heating chambers 5, and the inner walls of multiple heating chambers 5 will be filled with solid paraffin blocks at the same time. The paraffin blocks inside the heating chamber 5 are heated by turning on the thermocouple 6. The paraffin blocks will become molten after being exposed to high temperature, and then the thermocouple 6 is controlled to be closed. The paraffin blocks in the molten state will quickly cool down and be fixedly connected to the bottom of the turntable 2, so that the polishing chip 32 will be driven to rotate when the turntable 2 rotates, realizing the grinding and polishing process. After polishing is completed, the paraffin block is heated again to a molten state to facilitate the removal of the polishing chip 32. Before each chip falls above the heating chamber 5, the staff should ensure that the paraffin in the heating chamber 5 is full and that the paraffin block can fit the chip every time.

[0037] like Figure 5 to Figure 6 As shown, the adjustment component includes a plurality of slide seats 11, and the plurality of slide seats 11 are fixedly mounted on the top of the workbench 1, the inner walls of the plurality of grinding wheels 4 are fixedly connected with a rotating rod 24, the bottom of the rotating rod 24 is rotatably connected with an inner slide block 10, the outer wall of each inner slide block 10 is slidably connected with the inner wall of each slide seat 11 and adapted to each other, and a transmission component is provided on one side of each inner slide block 10, and the transmission component is used to drive the inner slide block 10 to slide inside the slide seat 11.

[0038] During operation: when the polishing wafer 32 gradually enters directly above the turntable 2, the inner slider 10 will slide outward inside the slide seat 11 through the transmission component. When sliding, the inner slider 10 will drive the grinding wheel 4 to move through the rotating rod 24. The sliding distance of the inner slider 10 inside the slide seat 11 is based on the outer diameter of the polishing wafer 32. After the position of the grinding wheel 4 is adjusted, its outer wall can fit tightly against the outer wall of the polishing wafer 32, so that the grinding wheel 4 can accurately grind the outer wall of the polishing wafer 32. The grinding wheel 4 can be flexibly adjusted according to the outer diameter of the polishing wafer 32.

[0039] like Figure 5 to Figure 6 As shown, a plurality of slides 9 are fixedly installed on the top of the workbench 1. The sizes of slides 19 and slides 2 11 are exactly the same. The distance between slides 19 and the motor 3 is consistent with the distance between slides 2 11 and the motor 3. The interior of slides 19 is slidably connected with inner slides 8. The tops of inner slides 8 are fixedly connected with outer expansion plates 7. The outer expansion plates 7 are located on the outside of the turntable 2.

[0040] During operation: when the placement plate 36 drives the polishing wafer 32 to move downward through the lifting assembly, the placement plate 36 will move along the inner side of the outer expansion plate 7 and squeeze it when descending, and the outer expansion plate 7 will move outward according to the outer diameter of the polishing wafer 32 after the placement plate 36 places it, and will slide inside the slide seat 1 9 through the inner slider 1 8. During the sliding process of the inner slider 1 8, the inner slider 2 10 will be driven by the transmission assembly to slide inside the slide seat 2 11, thereby adjusting the position of the grinding wheel 4, and the sliding distance of the inner slider 2 10 is the same as the sliding distance of the inner slider 1 8, so that the adjusted position of the grinding wheel 4 can just fit the outer wall edge of the polishing wafer 32.

[0041] like Figures 4 to 5 As shown, the upper half of the outward expansion plate 7 is in an arc shape, the lower half of the outward expansion plate 7 is in a straight shape, and the distance between the inner side of the straight portion of the outward expansion plate 7 and the polishing wafer 32 and the distance between the grinding wheel 4 and the polishing wafer 32 are always the same, and the difference between the circumferential surface formed by the straight portions of the multiple outward expansion plates 7 and the circumferential surface formed by the multiple grinding wheels 4 is just the thickness of the placement plate 36.

[0042] During operation: the placement plate 36 enters the straight area of ​​the outer expansion plate 7 along the arc portion of the outer expansion plate 7, and the outer expansion plate 7 is gradually squeezed and moved outward by the placement plate 36. When it falls onto the top of the turntable 2, the edge outer wall of the placement plate 36 just fits with the inner side of the outer expansion plate 7, and because the gap between the circumferential surface formed by the straight portions of the multiple outer expansion plates 7 and the circumferential surface formed by the multiple grinding wheels 4 is just the thickness of the placement plate 36, after the outer expansion plate 7 is expanded, the outer wall of the grinding wheel 4 can just fit with the outer wall edge of the polishing wafer 32, thereby achieving the effect of adjusting the grinding wheel 4.

[0043] like Figure 5 to Figure 6 As shown, the transmission assembly includes a rack plate 13, one side of the inner slider 18 is fixedly connected to an external rod 12, the outer wall of the external rod 12 is fixedly connected to the inner wall of the rack plate 13, the teeth of the rack plate 13 are meshed with a gear 15, the teeth of the gear 15 are meshed with a gear 2 16, the teeth of the gear 2 16 are meshed with a rack plate 2 17, the inner wall of one end of the rack plate 2 17 is fixedly connected to an external rod 22, one end of the external rod 22 is fixedly connected to one side of the inner slider 2 10, and the inner side of the slide seat 9 is fixedly connected to the outer side of the slide seat 9. A slide bar groove 14 is provided on the wall, and the slide bar groove 14 is slidably connected to the outer wall of the external rod 12 and adapted to each other. A slide bar groove 23 is provided on the side inner wall of the slide seat 2 11, and the slide bar groove 23 is slidably connected to the outer wall of the external rod 22 and adapted to each other. The size and number of teeth of gear 15 and gear 2 16 are consistent, and the teeth size of rack plate 13 and rack plate 2 17 are the same. The shafts of gear 15 and gear 2 16 are rotatably connected with a clamping member 18, and the clamping member 18 is fixedly installed on the top of the workbench 1.

[0044] During operation: when the inner slider 18 slides inside the slide seat 19, the rack plate 13 is driven to move outward through the external rod 12, and the rack plate 13 is driven to move outward through the gear 15 and the gear 2 16, and the rack plate 2 17 is driven to slide outward inside the slide seat 2 11 through the external rod 22. Therefore, when the polishing wafer 32 squeezes the external expansion plate 7 to move outward, the grinding wheel 4 is moved outward, so that the position of the grinding wheel 4 can be just located at the polishing of the polishing wafer 32. At the position, the sliding bar groove 14 and the sliding bar groove 23 are opened to facilitate the sliding of the external rod 12 and the external rod 22, and also improve the stability of the inner slider 18 in the slide seat 19 and the inner slider 2 10 in the slide seat 2 11. Since the size and number of teeth of the gear 15 and the gear 2 16 are consistent, the teeth of the rack plate 13 and the rack plate 2 17 are the same size, which ensures that the sliding distance of the inner slider 18 is the same as the sliding distance of the inner slider 2 10, and the position of the gear 15 and the gear 2 16 is fixed by the clamping member 18.

[0045] like Figures 4 to 5 As shown, one side of each inner sliding block 8 is fixedly connected with a moving rod 19, and the moving rod 19 is plugged into the inner wall of the sliding seat 9. A return spring 20 is arranged on the outside of the moving rod 19, and one end of the return spring 20 is fixedly connected to one side of the inner sliding block 8, and the other end of the return spring 20 is fixedly connected to the inner side of the sliding seat 9. One end of each moving rod 19 is fixedly connected with a limiting sleeve 21.

[0046] During operation: when the polishing wafer 32 is polished and needs to be taken out, the inner slider 8 will be reset by the reset spring 20, and the stability of the entire reset process will be improved by the moving rod 19 and the reset spring 20, and the inner slider 8 will drive the outer expansion plate 7 to reset, so that the next wafer to be polished can be placed on the top of the turntable 2 and squeeze the outer expansion plate 7 again, and the inner slider 8 will drive the grinding wheel 4 to reset through the transmission assembly when resetting, so that the grinding wheel 4 can adjust its position again according to the outer diameter of the next wafer.

[0047] like Figures 7 and 8 As shown, the linkage assembly includes two base plates 30, which are fixedly installed on the top of the workbench 1, and the tops of the two base plates 30 are rotatably connected with a transmission ring 1 25 and a transmission ring 2 28 respectively. A transmission belt 27 is transmission-connected between the outer walls of the transmission ring 1 25 and the transmission ring 28, and the inner wall of the transmission belt 27 is transmission-connected with an inner ring 26. The inner ring 26 is fixedly installed on the outer wall of the rotating rod 24, and a driving gear 31 is fixedly connected to the outer wall of the output shaft of the motor 3. The outer walls of the shafts at multiple transmission rings 28 are all fixedly connected with driven gears 29, and the teeth of the driving gear 31 are respectively meshed with the teeth of multiple driven gears 29.

[0048] During operation: the transmission belt 27 is fixed in position by the transmission ring 28 and the transmission ring 1 25. After the grinding wheel 4 is adjusted in position, the inner ring 26 can always slide along the inner wall of the transmission belt 27, so that no matter where the grinding wheel 4 moves to, the transmission ring 28 and the transmission ring 1 25 can drive the inner ring 26 to rotate when they rotate. When the inner ring 26 rotates, it drives the grinding wheel 4 to rotate through the rotating rod 24, thereby achieving the effect of polishing the edge of the polishing wafer 32, and the base plate 30 fixes the position of the transmission ring 28 and the transmission ring 1 25 to maintain the stability of the transmission of the transmission belt 27. When the motor 3 is started, the polishing wafer 32 is driven to rotate through the turntable 2, and the driving gear 31 is driven to rotate. When the driving gear 31 rotates, it drives the driven gear 29 to rotate. When the driven gear 29 rotates, it drives the transmission ring 2 28 to rotate, thereby achieving the effect of driving the inner ring 26 to rotate.

[0049] like Figures 9 and 10 As shown, the lifting assembly includes an outer base 33, the inner wall of the outer base 33 is slidably connected to an iron block 35, the bottom of the inner wall of the outer base 33 is fixedly installed with an electromagnet 37, one side of the iron block 35 is fixedly connected to one side of the placement plate 36, the bottom of the outer base 33 is fixedly connected to a base 34, and the bottom of the base 34 is slidably connected to the workbench 1.

[0050] During operation: when it is necessary to place the polishing wafer 32 on top of the heating chamber 5 and connect it to the turntable 2, first pass current through the electromagnet 37. When current is passed through the electromagnet 37, it can generate a magnet to attract the iron block 35. After being attracted, the iron block 35 will slide downward along the inside of the outer base 33 until it is adsorbed by the electromagnet 37. When the iron block 35 descends, it can drive the placement plate 36 to move downward. When the placement plate 36 moves downward, it will gradually squeeze the outer expansion plate 7, so that the outer expansion plate 7 moves outward to adjust the position of the grinding wheel 4. When the placement plate 36 descends to the bottom of the turntable 2, the polishing wafer 32 will fall on the top of the heating chamber 5, and when the placement plate 36 is below the turntable 2, the outer expansion plate 7 will remain stable after expansion.

[0051] like Figures 9 and 10 As shown, a spring 38 is fixedly connected to the top of the iron block 35, and the spring 38 is plugged into the inner wall of the top surface of the outer seat 33. A plug-in rod 39 is provided outside the plug-in rod 39, and the two ends of the plug-in rod 39 are fixedly connected to the spring 38 and the top of the outer seat 33 respectively.

[0052] During operation: When the grinding is completed, the connection assembly is removed to fix the polishing wafer 32, and the current passing through the electromagnet 37 is turned off. At this time, under the action of the spring 38 and the plug-in rod 39, the iron block 35 will drive the placement plate 36 to rise and reset. At this time, the polishing wafer 32 is polished and is not connected to the turntable 2. When the placement plate 36 rises, the polishing wafer 32 is separated from the turntable 2, and the polishing wafer 32 can be restored to its initial position, and the staff can easily take out the polishing wafer 32.

[0053] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A polishing device for silicon carbide crystal, comprising a workbench (1), characterized in that: A motor (3) is fixedly installed at the center of the top of the workbench (1); a turntable (2) is fixedly connected to the top of the output shaft of the motor (3); a plurality of placement plates (36) are arranged above the top of the turntable (2); a polishing wafer (32) is placed between the tops of the plurality of placement plates (36); a lifting assembly is arranged on the outer side of the placement plates (36); a connecting assembly for fixing the polishing wafer (32) above the turntable (2) is arranged on the top of the turntable (2); a plurality of grinding wheels (4) are arranged on the outer side of the turntable (2); an adjusting assembly for driving the grinding wheel (4) to adjust its position is arranged at the bottom of the grinding wheel (4); and a linkage assembly for driving the grinding wheel (4) to rotate is arranged between the motor (3) and the plurality of grinding wheels (4).

2. The polishing device for silicon carbide crystal according to claim 1, characterized in that: A plurality of heating chambers (5) are fixedly mounted on the top of the turntable (2); a plurality of thermocouples (6) are fixedly mounted on the outer walls of the plurality of heating chambers (5); the inner walls of the plurality of heating chambers (5) are filled with paraffin solid blocks, and the thermocouples (6) heat the paraffin blocks inside the heating chambers (5).

3. The polishing device for silicon carbide crystal according to claim 2, characterized in that: The adjustment assembly comprises a plurality of slide seats (11), the plurality of slide seats (11) are fixedly mounted on the top of the workbench (1), the inner walls of the plurality of grinding wheels (4) are fixedly connected with a rotating rod (24), the bottom of the rotating rod (24) is rotatably connected with an inner slide block (10), the outer wall of each inner slide block (10) is slidably connected to the inner wall of each slide seat (11) and is mutually adapted, and a transmission assembly is arranged on one side of each inner slide block (10), the transmission assembly is used to drive the inner slide block (10) to slide inside the slide seat (11).

4. The polishing device for silicon carbide crystal according to claim 3, characterized in that: A plurality of slide seats (9) are fixedly mounted on the top of the workbench (1). The sizes of the slide seats (9) and the slide seats (11) are exactly the same. The distance between the slide seat (9) and the motor (3) is consistent with the distance between the slide seat (11) and the motor (3). The interior of the slide seat (9) is slidably connected to an inner slide block (8). The top of the inner slide block (8) is fixedly connected to an outer expansion plate (7). The outer expansion plate (7) is located on the outer side of the turntable (2).

5. The polishing device for silicon carbide crystal according to claim 4, characterized in that: The upper half of the outer expansion plate (7) is in an arc shape, the lower half of the outer expansion plate (7) is in a straight shape, and the difference between the circumferential surface formed by the straight portions of the plurality of outer expansion plates (7) and the circumferential surface formed by the plurality of grinding wheels (4) is exactly the thickness of the placement plate (36).

6. The polishing device for silicon carbide crystal according to claim 5, characterized in that: The transmission assembly comprises a rack plate (13), one side of the inner slide block (8) is fixedly connected to an external rod (12), the outer wall of the external rod (12) is fixedly connected to the inner wall of the rack plate (13), the teeth of the rack plate (13) are meshed with a gear (15), the teeth of the gear (15) are meshed with a gear (16), the teeth of the gear (16) are meshed with a rack plate (17), the inner wall of one end of the rack plate (17) is fixedly connected to an external rod (22), one end of the external rod (22) is fixedly connected to the inner slide block (8), and the outer wall of the external rod (22) is fixedly connected to the inner slide block (8). One side of the block 2 (10) is fixedly connected, the inner wall of the side surface of the slide seat 1 (9) is provided with a slide bar groove 1 (14), the slide bar groove 1 (14) is slidably connected to the outer wall of the external rod 1 (12) and is adapted to each other, the inner wall of the side surface of the slide seat 2 (11) is provided with a slide bar groove 2 (23), the slide bar groove 2 (23) is slidably connected to the outer wall of the external rod 2 (22) and is adapted to each other, the shafts of the gear 1 (15) and the gear 2 (16) are rotatably connected with a clamping member (18), and the clamping member (18) is fixedly installed on the top of the workbench (1).

7. The polishing device for silicon carbide crystal according to claim 6, characterized in that: A moving rod (19) is fixedly connected to one side of each inner sliding block (8), the moving rod (19) is plugged into the inner wall of the sliding seat (9), a return spring (20) is arranged outside the moving rod (19), one end of the return spring (20) is fixedly connected to one side of the inner sliding block (8), the other end of the return spring (20) is fixedly connected to the inner side of the sliding seat (9), and one end of each moving rod (19) is fixedly connected to a limiting sleeve (21).

8. The polishing device for silicon carbide crystal according to claim 7, characterized in that: The linkage assembly comprises two base plates (30), the base plates (30) are fixedly mounted on the top of the workbench (1), the tops of the two base plates (30) are rotatably connected with a transmission ring 1 (25) and a transmission ring 2 (28), the outer walls of the transmission ring 1 (25) and the transmission ring 2 (28) are transmission-connected with a transmission belt (27), the inner wall of the transmission belt (27) is transmission-connected with an inner ring (26), the inner ring (26) is fixedly mounted on the outer wall of the rotating rod (24), the outer wall of the output shaft of the motor (3) is fixedly connected with a driving gear (31), the outer walls of the shafts at the plurality of transmission rings 2 (28) are all fixedly connected with driven gears (29), and the teeth of the driving gear (31) are respectively meshed with the teeth of the plurality of driven gears (29).

9. The polishing device for silicon carbide crystal according to claim 8, characterized in that: The lifting assembly comprises an outer base (33), an iron block (35) is slidably connected to the inner wall of the outer base (33), an electromagnet (37) is fixedly installed at the bottom of the inner wall of the outer base (33), one side of the iron block (35) is fixedly connected to one side of a placement plate (36), the bottom of the outer base (33) is fixedly connected to a base (34), and the bottom of the base (34) is slidably connected to the workbench (1).

10. The polishing device for silicon carbide crystal according to claim 9, characterized in that: A spring (38) is fixedly connected to the top of the iron block (35), and the spring (38) is plugged into the inner wall of the top surface of the outer seat (33). A plug-in rod (39) is arranged outside the plug-in rod (39), and the two ends of the plug-in rod (39) are fixedly connected to the spring (38) and the top of the outer seat (33) respectively.

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