Silicon carbide wafer thinning grinding wheel and preparation method thereof

Abstract

The invention belongs to the technical field of grinding tool preparation, and particularly relates to a silicon carbide wafer thinning grinding wheel which comprises a base body. The grinding material layer is arranged on the base body; the grinding material layer is prepared from the following components in parts by mass: 45 to 65 parts of modified diamond, 5 to 10 parts of soft grinding material, 20 to 35 parts of low-temperature glass powder, 5 to 15 parts of filler and 0.5 to 5 parts of pore forming agent; the surface of the modified diamond is coated with a silicon dioxide film. The invention further comprises preparation and application of the silicon carbide wafer thinning grinding wheel. According to the silicon carbide wafer thinning grinding wheel, diamond distribution is uniform, and the holding force is good; the combination with low-temperature glass powder is firm and not easy to fall off; the prepared grinding wheel is high in hardness, small in abrasive ratio during grinding of the grinding wheel and high in grinding efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of grinding tool preparation, and particularly relates to a silicon carbide wafer thinning grinding wheel and a preparation method thereof. Background Art

[0002] The semiconductor material silicon carbide has the characteristics of overall high voltage resistance and high thermal conductivity, and is widely used in medium voltage markets such as high voltage and high frequency devices.

[0003] Compared with single crystal silicon, silicon carbide is harder, more brittle, and has a higher manufacturing cost. It needs to be thinned on the back by grinding to reduce the chip's on-resistance and improve the chip's heat dissipation performance. However, due to its high hardness and low fracture toughness, silicon carbide is very prone to surface and subsurface damage such as microcracks, broken pits, amorphous, and dislocations during the grinding process, which seriously affects the yield and processing cost of semiconductor substrates.

[0004] Existing grinding wheels, such as patent announcement number CN102363578B discloses a ceramic bond grinding wheel, which is made of clay, feldspar, boron-containing glass, bentonite, and manganite to make a high-strength and high-shrinkage engineering ceramic bond, which is then combined with a mixed material grinding material, and the opacifying effect of boron glass is used to promote glass nucleation, and the flux bentonite and manganite powder are used to promote the formation of a high-strength and high-shrinkage engineering ceramic structure, which is cold-pressed and high-pressure molded, and fired at a certain temperature to obtain a ceramic bond grinding wheel. The ceramic bond grinding wheel needs to be fired at 1250°C, which requires high energy consumption, resulting in waste of resources and increased production costs.

[0005] Patent publication number CN112497087A discloses a bronze-based diamond grinding wheel with high bending strength and a preparation method thereof. Copper-tin pre-alloyed powder is added to the copper base, and the alloying degree of the bronze base is effectively improved by modifying and adding diamond powder. Boron carbide, chromium oxide, silicon carbide and other binder components are added to greatly enhance the bonding force between the grinding wheel base material and the binder. The strength of the obtained grinding wheel is greatly improved, and it is not easy to break, fall off, or lose edges during processing. Although the bronze-based diamond grinding wheel of the patent has high bending strength, the binder has not been subjected to pore-forming treatment, and the self-sharpening property of the obtained grinding wheel is general. The continuous thinning processing ability of materials such as silicon carbide is poor, which easily causes the workpiece to be scrapped due to cracks, and cannot meet the high-precision processing of semiconductor materials.

[0006] Patent publication number CN104230319A discloses a ceramic low-temperature binder and its preparation process, wherein the raw materials of the binder are composed of 10% to 18% kaolin, 20% to 25% albite, 20% to 25% low-boron glass, 30% to 40% high-boron glass, 5% to 10% lithium carbonate and 1% to 5% calcium carbonate by weight percentage. The sintering temperature of the binder is 900°C, and it has a certain reaction ability with abrasives. The binder has high holding power with abrasives and the binder itself has high strength. However, the silicon carbide ceramic grinding wheel prepared by the binder has low durability and cannot meet the requirements of grinding.

[0007] In summary, in the prior art, the diamond in the silicon carbide thinning grinding wheel has strong chemical inertness and poor wettability to the bonding material, so it is difficult for the bonding agent matrix to firmly hold the diamond; the abrasive falls off quickly, the overall structural uniformity is poor, the strength is low, the wear ratio is large during processing, and the grinding efficiency is low. Summary of the invention

[0008] Aiming at the problems of poor overall uniformity of the existing silicon carbide thinning grinding wheel, low diamond holding force, low strength and insufficient grinding efficiency, the present invention aims to provide a silicon carbide wafer thinning grinding wheel and a preparation method thereof. The grinding wheel prepared by the present invention has uniform diamond distribution and good holding force; it is firmly combined with low-temperature glass powder and is not easy to fall off; the grinding wheel prepared by the present invention has high hardness, low wear ratio during grinding, and high grinding efficiency.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions: A silicon carbide wafer thinning grinding wheel, comprising a base body; an abrasive layer arranged on the base body; The abrasive layer comprises, by weight, 45 to 65 parts of modified diamond, 5 to 10 parts of soft abrasive, 20 to 35 parts of low-temperature glass powder, 5 to 15 parts of filler, and 0.5 to 5 parts of pore former; The modified diamond is a diamond whose surface is coated with a silicon dioxide film.

[0010] The surface of the modified diamond is coated with a silicon dioxide film, which has active oxygen groups and can react with low-temperature glass powder, thereby effectively improving the interface bonding force between the diamond and the low-temperature glass powder.

[0011] Furthermore, the diamond is ultrafine diamond, preferably ultrafine diamond with a particle size of 1000-4000 mesh, more preferably 2000 mesh. The diamond type can be polycrystalline diamond powder and / or single crystal diamond powder.

[0012] Furthermore, the soft abrasive includes at least one of cerium dioxide, ferroferric oxide and magnesium oxide.

[0013] Furthermore, the low-temperature glass powder is composed of clay powder, feldspar powder, boron glass powder, Li2O2 and SiO2.

[0014] Furthermore, the low-temperature glass powder is composed of 5 to 25 parts of clay powder, 5 to 20 parts of feldspar powder, 39 to 60 parts of boron glass powder, 1 to 5 parts of Li2O2 and 9 to 18 parts of SiO2 by weight.

[0015] Furthermore, the filler includes at least one of calcium carbonate, calcium silicate and barium sulfate.

[0016] Preferably, the filler is calcium silicate; more preferably, the filler is calcium silicate whisker, the calcium silicate whisker has a diameter of 0.2-5 μm and an aspect ratio of (3-20):1.

[0017] The filler has a reinforcing and toughening effect in the present invention, which increases the strength and toughness of the binder in the present invention, and has a certain elasticity, so that when grinding the corners of semiconductor wafers, full wrap grinding can be achieved without brittle fracture of the diamond layer or the binder layer.

[0018] Furthermore, the pore-forming agent includes at least one of soda lime borosilicate glass hollow spheres, alumina hollow spheres, graphite and sodium chloride.

[0019] An appropriate amount of pore-forming agent is added to the grinding wheel to achieve a certain chip holding and heat dissipation effect. The low-temperature glass powder silicon carbide wafer thinning grinding wheel has good comprehensive grinding performance during the grinding process, and the surface roughness fluctuation range of the ground silicon wafer is small.

[0020] The present invention also provides a method for preparing a silicon carbide wafer thinning grinding wheel, comprising the following steps: S1: Add the modifier to an ethanol-water mixed solution, mix well, hydrolyze at 45-60°C for 0.5-8 h to obtain a hydrolysis solution of the modifier, add diamond to the hydrolysis solution, stir at 50-100°C for 0.5-8 h, and finally stand at 20-45°C for evaporation for 24-48 h to obtain modified diamond.

[0021] S2: Stir the modified diamond, soft abrasive and filler in a mixer for 1-3 hours, take out and sieve to obtain a mixture A; S3: crushing, ball-milling, drying and sieving the low-temperature glass powder to obtain a mixture B; S4: Stir the pore-forming agent, mixed material A and mixed material B in a mixer for 30-60 min, take out and sieve to obtain mixed material C; S5: placing the mixed material C and the matrix into a mold for pressing and molding at a pressure of 1-6 MPa, a pressing temperature of 180-230°C, and a holding time of 30-120 min; S6: placing the grinding wheel pressed in S5 in an oven, heating it to 600-700°C at a heating rate of 1-5°C / min, keeping it at that temperature for 12-24h, and then cooling it to room temperature to obtain the desired grinding wheel blank; S7: The grinding wheel blank obtained in S6 is subjected to base body processing, inner and outer circles and grinding wheel layer dressing to obtain a finished grinding wheel.

[0022] Further, in S1, the modifier includes at least one of tetramethoxysilane, trimethoxysilane, triethoxysilane, trimethoxypropylsilane, triethoxypropylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, aminopropyltriethoxysilane and mercaptopropyltriethoxysilane.

[0023] Furthermore, in S1, the volume ratio of the modifier to the ethanol-water mixed solution is (1-4): (35-40).

[0024] Preferably, the volume ratio of the modifier to the ethanol-water mixed solution is 1:35, 1:36, 1:37, 2:38, 2:39, 2:40, 3:40 or 4:40.

[0025] Furthermore, in S1, the volume ratio of ethanol to water in the ethanol-water mixed solution is (20-50): (50-80).

[0026] Preferably, the volume ratio of ethanol to water is 50:50, 45:55, 40:60, 35:65, 30:70, 25:75 or 20:80.

[0027] Furthermore, in S1, the liquid-to-solid ratio of the modifier to diamond is (1-4):(10-30), and the unit of the liquid-to-solid ratio is mL / g.

[0028] Furthermore, the sieving screen in S2~4 is 100~200 mesh. Beneficial Effects

[0029] The silicon carbide wafer thinning grinding wheel provided by the present invention has a diamond surface coated with a chemically active silicon dioxide film, so that it can react with resin under low-temperature sintering conditions, thereby improving the holding force of the resin matrix on the diamond and increasing the service life of the grinding wheel, thereby improving the processing efficiency of the low-temperature glass powder grinding wheel.

[0030] The silicon carbide wafer thinning grinding wheel provided by the present invention is added with fillers such as calcium silicate whiskers, which play a role in strengthening and toughening, so that the low-temperature glass powder prepared by the present invention has increased strength and toughness, and has a certain elasticity, so that brittle fracture of the diamond layer or the binder layer does not occur during the grinding process.

[0031] The silicon carbide wafer thinning grinding wheel provided by the present invention is added with a pore-forming agent and has a higher porosity. The porous structure plays the role of accommodating chips and increasing the sharpness of the cutter head. The surface quality of the processed workpiece is good and the processing efficiency is high. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments. Example

[0033] A silicon carbide wafer thinning grinding wheel, comprising a base body; an abrasive layer arranged on the base body; The abrasive layer comprises, by weight, 45 parts of modified diamond, 5 parts of ferric oxide, 5 parts of magnesium oxide, 25 parts of low-temperature glass powder, 10 parts of calcium silicate whiskers, and 3 parts of hollow alkali-lime borosilicate glass spheres. The low-temperature glass powder is composed of 15 parts of clay powder, 15 parts of feldspar powder, 50 parts of boron glass powder, 3 parts of Li2O2, and 17 parts of SiO2.

[0034] A method for preparing a silicon carbide wafer thinning grinding wheel comprises the following steps: S1: Add 10 mL of tetramethoxysilane to 190 mL of ethanol-water mixed solution (the volume ratio of ethanol to water is 2:8), mix well, and hydrolyze at 50°C for 4 h to obtain a hydrolysis solution of the modifier. Add 20 g of 2000 mesh polycrystalline diamond to the hydrolysis solution, stir at 80°C for 6 h, and finally stand at 25°C for evaporation for 24 h to obtain modified diamond.

[0035] S2: Stir the modified diamond, ferroferric oxide, magnesium oxide and calcium silicate whisker in a mixer for 1 hour, take out and sieve the mixture with a 100-mesh sieve to obtain a mixture A; S3: crushing, ball-milling, drying, and sieving the polyurethane modified epoxy resin DER858, with a 100-mesh sieve to obtain a mixture B; S4: mixing the soda lime borosilicate glass hollow balls, mixture A and mixture B in a mixer for 40 minutes, taking out and sieving to obtain mixture C; S5: putting the mixed material C and the matrix into a mold for pressing at a pressure of 3 MPa, a pressing temperature of 200 °C, and a holding time of 60 min; S6: placing the grinding wheel pressed in S5 in an oven, heating it to 680°C at a heating rate of 2°C / min, keeping it at that temperature for 12 hours, and then cooling it to room temperature to obtain the desired grinding wheel blank; S7: The grinding wheel blank obtained in S6 is subjected to base body processing, inner and outer circles and grinding wheel layer dressing to obtain a finished grinding wheel.

[0036] In the S4, the pore size of the soda lime borosilicate glass hollow sphere is 5-20 μm.

[0037] Test results: The silicon carbide wafer thinning grinding wheel prepared above was applied to a silicon carbide special grinding machine for on-machine testing, grinding a 4-inch silicon carbide ingot, and the grinding process parameters were: grinding wheel speed 1500 r / min, suction cup speed 120 r / min, feed rate 1.0 / 0.4 / 0.2 μm / s. The grinding wheel prepared in this embodiment has good diamond holding force, and no diamond falls off during the ingot processing; the workpiece removal amount is 30 μm, the time consumption is 3min14s, the wear mark is uniform and there is no abnormal sound, the surface roughness Ra is 14nm, and the grinding wheel wear ratio is 0. Example

[0038] A silicon carbide wafer thinning grinding wheel, comprising a base body; an abrasive layer arranged on the base body; The abrasive layer comprises, by weight, 45 parts of modified diamond, 5 parts of ferric oxide, 5 parts of magnesium oxide, 25 parts of low-temperature glass powder, 15 parts of calcium silicate whiskers, and 3 parts of soda lime borosilicate glass hollow spheres. The low-temperature glass powder is composed of 15 parts of clay powder, 15 parts of feldspar powder, 50 parts of boron glass powder, 3 parts of Li2O2 and 17 parts of SiO2.

[0039] A method for preparing a silicon carbide wafer thinning grinding wheel comprises the following steps: S1: Add 10 mL of tetramethoxysilane to 190 mL of ethanol-water mixed solution (the volume ratio of ethanol to water is 2:8), mix well, and hydrolyze at 50°C for 4 h to obtain a hydrolysis solution of the modifier. Add 20 g of 2000 mesh polycrystalline diamond to the hydrolysis solution, stir at 80°C for 6 h, and finally stand at 25°C for evaporation for 24 h to obtain modified diamond.

[0040] S2: Stir the modified diamond, ferroferric oxide, magnesium oxide and calcium silicate whisker in a mixer for 1 hour, take out and sieve the mixture with a 100-mesh sieve to obtain a mixture A; S3: crushing, ball-milling, drying, and sieving the polyurethane modified epoxy resin DER858, with a 100-mesh sieve to obtain a mixture B; S4: mixing the soda lime borosilicate glass hollow balls, mixture A and mixture B in a mixer for 40 minutes, taking out and sieving to obtain mixture C; S5: putting the mixed material C and the matrix into a mold for pressing at a pressure of 3 MPa, a pressing temperature of 200 °C, and a holding time of 60 min; S6: placing the grinding wheel pressed in S5 in an oven, heating it to 680°C at a heating rate of 2°C / min, keeping it at that temperature for 12 hours, and then cooling it to room temperature to obtain the desired grinding wheel blank; S7: The grinding wheel blank obtained in S6 is subjected to base body processing, inner and outer circles and grinding wheel layer dressing to obtain a finished grinding wheel.

[0041] In the S4, the pore size of the soda lime borosilicate glass hollow sphere is 5-20 μm.

[0042] Test results: The silicon carbide wafer thinning grinding wheel prepared above was applied to a silicon carbide special grinding machine for on-machine testing, grinding a 4-inch silicon carbide ingot, and the grinding process parameters were: grinding wheel speed 1500 r / min, suction cup speed 120 r / min, feed rate 1.0 / 0.4 / 0.2 μm / s. The grinding wheel prepared in this embodiment has good diamond holding force, and no diamond falls off during the ingot processing; the workpiece removal amount is 30 μm, the time consumption is 3min8s, the wear mark is uniform and there is no abnormal sound, the surface roughness Ra is 11nm, and the grinding wheel wear ratio is 0. Example

[0043] A silicon carbide wafer thinning grinding wheel, comprising a base body; an abrasive layer arranged on the base body; The abrasive layer comprises, by weight, 40 parts of modified diamond, 10 parts of ferroferric oxide, 5 parts of magnesium oxide, 25 parts of low-temperature glass powder, 10 parts of calcium silicate whiskers, and 3 parts of soda lime borosilicate glass hollow spheres. The low-temperature glass powder is composed of 10 parts of clay powder, 20 parts of feldspar powder, 50 parts of boron glass powder, 5 parts of Li2O2 and 15 parts of SiO2.

[0044] A method for preparing a silicon carbide wafer thinning grinding wheel comprises the following steps: S1: Add 10 mL of aminopropyltriethoxysilane to 190 mL of ethanol-water mixed solution (the volume ratio of ethanol to water is 2:8), mix well, and hydrolyze at 50°C for 4 h to obtain a hydrolysis solution of the modifier. Add 20 g of 2000 mesh polycrystalline diamond to the hydrolysis solution, stir at 80°C for 6 h, and finally stand at 25°C for evaporation for 24 h to obtain modified diamond.

[0045] S2: Stir the modified diamond, ferroferric oxide, magnesium oxide and calcium silicate whisker in a mixer for 1 hour, take out and sieve the mixture with a 100-mesh sieve to obtain a mixture A; S3: crushing, ball-milling, drying, and sieving the polyurethane modified epoxy resin EPU-618, the sieve having a mesh size of 100, to obtain a mixture B; S4: mixing the soda lime borosilicate glass hollow balls, mixture A and mixture B in a mixer for 40 minutes, taking out and sieving to obtain mixture C; S5: putting the mixed material C and the matrix into a mold for pressing at a pressure of 3 MPa, a pressing temperature of 200 °C, and a holding time of 60 min; S6: placing the grinding wheel pressed in S5 in an oven, heating it to 680°C at a heating rate of 2°C / min, keeping it at that temperature for 12 hours, and then cooling it to room temperature to obtain the desired grinding wheel blank; S7: The grinding wheel blank obtained in S6 is subjected to base body processing, inner and outer circles and grinding wheel layer dressing to obtain a finished grinding wheel.

[0046] In the S4, the pore size of the soda lime borosilicate glass hollow sphere is 5-20 μm.

[0047] Test results: The silicon carbide wafer thinning grinding wheel prepared above was applied to a silicon carbide special grinding machine for on-machine testing, grinding a 4-inch silicon carbide ingot, and the grinding process parameters were: grinding wheel speed 1500 r / min, suction cup speed 120 r / min, feed rate 1.0 / 0.4 / 0.2μm / s. The grinding wheel prepared in this embodiment has good diamond holding force, and no diamond falls off during the ingot processing; the workpiece removal amount is 30μm, the time consumption is 3min24s, the wear mark is uniform and there is no abnormal sound, the surface roughness Ra is 15nm, and the grinding wheel wear ratio is 0.

[0048] Compared with Example 1, the only difference is that the diamond used in the abrasive layer of the silicon carbide wafer thinning grinding wheel is not modified, and the other operations and parameters are the same as those in Example 1.

[0049] Test results: The silicon carbide wafer thinning grinding wheel prepared above was applied to a silicon carbide special grinding machine for on-machine testing to grind a 4-inch silicon carbide ingot. The grinding process parameters were: grinding wheel speed 1500 r / min, suction cup speed 120 r / min, feed rate 1.0 / 0.4 / 0.2μm / s. The grinding wheel prepared in this comparative example had diamond shedding during the grinding process, the workpiece removal amount was 30μm, the grinding time was 3min48s, the wear marks were uniform and there was no abnormal sound, the surface roughness Ra was 42nm, and the grinding wheel wear ratio was 0.36μm / piece.

[0050] Compared with Example 1, the only difference is that a silicon carbide wafer thinning grinding wheel has an abrasive layer without calcium silicate whiskers added thereto, and other operations and parameters are the same as those in Example 1.

[0051] Test results: The silicon carbide wafer thinning grinding wheel prepared above was applied to a silicon carbide special grinding machine for on-machine testing, grinding a 4-inch silicon carbide ingot, and the grinding process parameters were: grinding wheel speed 1500 r / min, suction cup speed 120 r / min, feed rate 1.0 / 0.4 / 0.2μm / s. The grinding wheel prepared in this comparative example has good diamond holding force, and no diamond falls off during chip processing. The workpiece removal amount is 30μm, the time consumption is 5min15s, the surface roughness Ra is 46nm, and the grinding wheel wear ratio is 0.47μm / piece.

[0052] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A silicon carbide wafer thinning grinding wheel, characterized in that: It includes a substrate; an abrasive layer disposed on the substrate; The abrasive layer comprises, by weight, 45-65 parts of modified diamond, 5-10 parts of soft abrasive, 20-35 parts of low-temperature glass powder, 5-15 parts of filler, and 0.5-5 parts of pore former; Modified diamond is diamond with a silicon dioxide film coated on its surface.

2. The grinding wheel according to claim 1, characterized in that The diamond particle size is 1000 mesh ~ 4000 mesh.

3. The grinding wheel according to claim 1, characterized in that: The soft abrasive includes at least one of cerium dioxide, ferric oxide and magnesium oxide; the low-temperature glass powder is composed of clay powder, feldspar powder, boron glass powder, Li2O2 and SiO2; the filler includes at least one of calcium carbonate, calcium silicate and barium sulfate; the pore-forming agent includes at least one of soda lime borosilicate glass hollow spheres, alumina hollow spheres, graphite and sodium chloride.

4. The grinding wheel according to claim 3, characterized in that The low-temperature glass powder is composed of 5 to 25 parts of clay powder, 5 to 20 parts of feldspar powder, 39 to 60 parts of boron glass powder, 1 to 5 parts of Li2O2 and 9 to 18 parts of SiO2, calculated by weight; the calcium silicate is a calcium silicate whisker with a diameter of 0.2 to 5 μm and an aspect ratio of (3 to 20):

1.

5. A method for preparing a silicon carbide wafer thinning grinding wheel, comprising the following steps: S1: adding a modifier to an ethanol-water mixed solution, hydrolyzing to obtain a hydrolysis solution of the modifier, adding diamond to the hydrolysis solution, stirring to react, and finally standing to evaporate to obtain a modified diamond; S2: Mixing and sieving the modified diamond, soft abrasive and filler to obtain a mixture A; S3: crushing the low-temperature glass powder, ball milling, drying, and sieving to obtain a mixture B; S4: mixing the pore former, the mixture A and the mixture B, and sieving to obtain the mixture C; S5: placing the mixed material C and the matrix into a mold for pressing; S6: placing the grinding wheel pressed in S5 in an oven, heating it to 600-700°C at a heating rate of 1-5°C / min, keeping it at that temperature for 12-24h, and then cooling it to room temperature to obtain the desired grinding wheel blank; S7: The grinding wheel blank obtained in S6 is subjected to base body processing, inner and outer circles and grinding wheel layer dressing to obtain a finished grinding wheel.

6. The preparation method according to claim 5, characterized in that: In step S1, the modifier includes at least one of tetramethoxysilane, trimethoxysilane, triethoxysilane, trimethoxypropylsilane, triethoxypropylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, aminopropyltriethoxysilane and mercaptopropyltriethoxysilane.

7. The preparation method according to claim 5, characterized in that: In step S1, the volume ratio of the modifier to the ethanol-water mixed solution is (1-4): (35-40); the volume ratio of ethanol to water in the ethanol-water mixed solution is (20-50): (50-80); the liquid-solid ratio of the modifier to diamond is (1-4): (10-30), and the unit of the liquid-solid ratio is mL / g.

8. The preparation method according to claim 5, characterized in that: In step S1, the hydrolysis temperature is 45-60°C, and the hydrolysis time is 0.5-8 h; the stirring reaction temperature is 50-100°C, and the stirring reaction time is 0.5-8 h; the static evaporation temperature is 20-45°C, and the static evaporation time is 24-48 h.

9. The preparation method according to claim 5, characterized in that: In steps S2-4, the sieve is 100-200 mesh; in step S5, the pressing molding conditions are: pressure of 1-6 MPa, pressing temperature of 180-230° C., and holding time of 30-120 min.

10. An application of the silicon carbide wafer thinning grinding wheel as claimed in any one of claims 1 to 4, characterized in that: It is used for chip back thinning, substrate thinning and laser modified layer thinning during silicon carbide wafer processing.