SiC thinning-oriented ceramic diamond grinding wheel and manufacturing method thereof

Abstract

The invention discloses a SiC thinning-oriented ceramic diamond grinding wheel and a preparation method thereof, and the grinding wheel comprises 25%-35% of a composite grinding material, 30%-40% of a ceramic bond, 25%-35% of a composite pore forming agent, 1%-1.5% of a dispersing agent, 2%-3% of a multi-effect modifier and 1%-1.5% of a lubricating agent. The preparation method specifically comprises the following steps: S1, weighing the composite abrasive material, the ceramic bond, the composite pore-forming agent, the dispersing agent, the multi-effect modifier and the lubricant according to the formula proportion; s2, preparing a mixed liquid A; s3, preparing mixed liquid B; s4, performing ultrasonic treatment, drying and sieving treatment on the mixed liquid B; s5, manufacturing a grinding wheel; through design optimization of the grinding wheel formula and the preparation method, better crystal ingot surface quality can be obtained in a SiC thinning machining scene, and meanwhile, stability and service life indexes in the service process of the grinding wheel are considered.

Description

Technical Field

[0001] This invention relates to the field of grinding technology, specifically to a ceramic diamond grinding wheel for SiC thinning and its manufacturing method. Background Technology

[0002] After growth and cutting, SiC ingots undergo a grinding process. Before being cut into silicon wafers of a specific thickness, the back side needs to be finely ground and thinned.

[0003] The shortcomings of existing technology: Traditional grinding wheels struggle to balance stable grinding performance with surface quality control. The main challenges in their manufacturing lie in: the high chemical stability of SiC, leading to poor interfacial wettability between conventional resin or ceramic binders and diamond abrasive grains, which can cause abrasive grains to detach and scratch the wafer, severely impacting post-grinding surface quality; and the potential for microcracks on the tool head surface due to the vaporization and discharge of substances like pore-forming agents during the sintering process, further affecting the final surface quality after thinning. Ultrafine diamond particles, due to their high surface energy, are prone to agglomeration, requiring a suitable dispersion process to prevent particle aggregation and ensure uniform material distribution throughout the tool head for stable cutting performance. Thinning involves a large number of abrasive grains in material removal, resulting in demanding grinding conditions, especially for high-efficiency thinning processes with large material removal volumes. Optimizing the grinding wheel formulation to improve tool head strength is crucial to prevent service failures such as tooth breakage due to insufficient mechanical strength. Summary of the Invention

[0004] The purpose of this invention is to provide a ceramic diamond grinding wheel for SiC thinning and a method for manufacturing the same, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a ceramic diamond grinding wheel for SiC thinning. The grinding wheel comprises 25%~35% composite abrasive, 30~40% ceramic binder, 25~35% composite pore-forming agent, 1~1.5% dispersant, 2~3% multi-effect modifier, and 1~1.5% lubricant.

[0006] Preferably, the composite abrasive coating comprises diamond, boron carbide, and silicon carbide in a volume fraction ratio of 15:2:1; the ceramic binder comprises 55-75% SiO2, 22-28% B2O3, 6-10% Al2O3, 5-8% Na2O, 3-5% K2O, and 0.05-0.1% MgO; the composite pore-forming agent comprises PMMA and hollow alumina beads in a volume fraction ratio of 2:5-2:7; the dispersant comprises styrene-maleic anhydride, ethanol, and deionized water; the multi-effect modifier comprises polycarboxylate superplasticizer, nano-neodymium oxide, and cerium oxide; and the lubricant comprises graphite and molybdenum disulfide.

[0007] This invention also provides a method for preparing a ceramic diamond grinding wheel for SiC thinning, the method specifically including the following steps: S1. Weigh the composite abrasive, ceramic binder, composite pore-forming agent, dispersant, multi-effect modifier and lubricant according to the formula ratio; S2. Prepare mixed liquid A; S3. Prepare mixed liquid B; S4. Perform ultrasonic treatment, drying and sieving on the mixed liquid B; S5. Making a grinding wheel.

[0008] Preferably, the method for preparing the ceramic binder in step S1 specifically includes the following steps: a1. Using a precision balance with an accuracy of not less than 1 mg, weigh SiO2, B2O3, Al2O3, Na2O, K2O and MgO according to the formula ratio; a2. After weighing, SiO2, B2O3, Al2O3, Na2O, K2O and MgO are poured into an alumina crucible in sequence and placed in a high-temperature furnace for firing at a temperature of 1650℃. a3. After reaching the firing temperature, keep it at that temperature for 2 hours, then pour the molten binder mixture into a metal bucket containing deionized water for water quenching. a4. The water-quenched binder is dried in an oven at a temperature of 60-80°C for 12 hours. a5. Pour the completely dried and dehydrated binder into the ball mill jar of the three-dimensional planetary ball mill for ball milling. Set the ball milling time to 4 hours. a6. After ball milling, the mixture is sieved three times using a 400-mesh sieve to obtain the ceramic binder for later use.

[0009] Preferably, step S2 specifically includes the following steps: b1. Pour the weighed dispersant, multi-effect modifier and lubricant into the ball mill jar of the three-dimensional planetary ball mill for ball milling and mixing. Set the ball milling time to 1~1.5 hours. b2. Add the powder after ball milling and mixing in step b1 to a solution of ethanol and deionized water. The total mass ratio of the mixed powder to the ethanol and deionized water solution is 1:15 to 1:20, and the ratio of ethanol to deionized water is 1:1 to 2:1. b3. Use an automated stirrer to stir the ethanol aqueous solution containing dispersant, multi-effect modifier and lubricant. Use a dispersing disc stirring paddle to stir and mix evenly to obtain mixture A. The stirring time is 30min~60min.

[0010] Preferably, step S3 specifically includes the following steps: c1. Pour the weighed composite abrasive and ceramic binder into the ball mill jar of the three-dimensional planetary ball mill for ball milling and mixing. Use an agate jar and agate balls, and set the ball milling time to 1.5 hours. c2. Use a 400# sieve to sieve the ball-milled composite abrasive and ceramic binder mixture, repeating the sieve 3 times; c3. Pour the composite abrasive and ceramic binder from step c2 together with the composite pore-forming agent into mixed liquid A; c4. Use an automated mixer to stir for 1~1.5 hours to obtain mixed liquid B, using a dispersion disc agitator.

[0011] Preferably, step S4 specifically includes the following steps: d1. Place the mixed liquid B into an ultrasonic vibrator for mixing and dispersion. Set the vibration frequency to 20 kHz and the ultrasonic vibration time to 0.5 to 1 hour. d2. Use an automated mixer to mix for 0.5 hours, using a dispersion disc type agitator. d3. Pour the mixture into a stainless steel tray and spread the liquid mixture B evenly in the stainless steel tray. Place the liquid mixture B in an 80℃ high-temperature oven for 6 hours to dry it and obtain the material. d4. Use a 400# sieve to sieve the material, remove the sieved material for later use, and repeat the sieving process 3 times.

[0012] Preferably, step S5 specifically includes the following steps: e1. Weigh the material according to the material weight calculated based on the mold design volume. The number of material portions should be consistent with the number of cutting heads designed for the grinding wheel. e2. After cleaning the mold, put the weighed single portion of material into the mold cavity, cover it with a pressure plate, and press it in the press. Set the pressure to 6MPa~8MPa and the time to 2min, and then demold the cutter head. e3. After all the cutting heads are pressed and demolded, they are buried in a ceramic box for sand treatment and then placed in a muffle furnace for sintering according to the set heating curve. e4. After the cutter head is sandblasted and the substrate is cleaned, the cutter head is bonded to the groove of the substrate using an epoxy resin adhesive, so that the spacing between each cutter head is equal and the side is perpendicular to the surface of the substrate. e5. After bonding, the grinding wheel tip end face is re-ground using a surface grinder.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. A ceramic diamond grinding wheel for SiC thinning and its manufacturing method are disclosed. Based on the correlation analysis of each component with the strength, thermal expansion coefficient and wettability of the binder, a self-made high-strength ceramic binder is experimentally tested and its bending strength can reach 80 MPa, which can meet the stable service requirements for SiC ingot thinning grinding scenarios.

[0014] 2. The present invention relates to a ceramic diamond grinding wheel for SiC thinning and its manufacturing method, which uses a composite pore-forming agent composed of PMMA and alumina hollow beads. Based on the different pore-forming principles of the two components, uniform pores are formed after sintering, while the strength of the cutting head is guaranteed under the retained alumina hollow sphere structure. At the same time, this structure can effectively avoid microcracks formed inside the cutting body during the heating and venting process.

[0015] 3. This ceramic diamond grinding wheel for SiC thinning and its manufacturing method employs a dispersant with styrene-maleic anhydride as the main component. Benefiting from the unique rheological properties of polymer materials and the steric hindrance effect of polymer molecular chains, the agglomeration of the various component powders is effectively avoided. Simultaneously, the self-water-reducing agent function ensures uniform powder dispersion while significantly shortening the subsequent drying process time.

[0016] 4. This invention relates to a ceramic diamond grinding wheel for SiC thinning and its manufacturing method, employing a multi-effect modifier composed of polycarboxylate superplasticizer, nano-neodymium oxide, and cerium oxide. The polycarboxylate superplasticizer effectively improves the dispersibility of the raw materials while chemically reacting with the binder in the grinding wheel to form a more stable chemical bond structure, effectively improving the strength, wear resistance, and impact resistance of the grinding wheel. Neodymium oxide and cerium oxide contribute to improved mechanical strength, and their high thermal conductivity effectively improves grinding conditions and provides a certain degree of polishing assistance. Attached Figure Description

[0017] Figure 1 The grinding wheel wear ratio and roughness test results of Embodiment 1 of the present invention; Figure 2 The grinding wheel wear ratio and surface roughness test results are for Example 2 of the present invention; Figure 3 The grinding wheel wear ratio and roughness test results are for Comparative Example 1 of the present invention; Figure 4The grinding wheel wear ratio and roughness test results are for Comparative Example 2 of the present invention; Figure 5 The microstructure of the thinning grinding wheel tip of the present invention is shown. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integrated connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a number" means two or more, unless otherwise explicitly specified.

[0022] Example 1 Please see Figure 1As shown, the present invention provides a ceramic diamond grinding wheel technology solution for SiC thinning: the grinding wheel includes 35% composite abrasive, 35% ceramic binder, 25% composite pore-forming agent, 1% dispersant, 3% multi-effect modifier and 1% lubricant, wherein the composite abrasive is coated with diamond, boron carbide and silicon carbide, and the volume fraction ratio is 15:2:1, the diamond is preferably 3000#, the corresponding boron carbide is preferably 2000#, and the silicon carbide particle size is preferably 2000#. By combining superhard abrasive with relatively coarser and relatively low hardness abrasive, the dual guarantee of high surface quality and high removal efficiency for grinding and thinning is achieved. The main abrasive is diamond micro powder that has undergone degreasing, roughening, sensitization and activation pretreatment processes followed by nickel plating.

[0023] The ceramic binder comprises 59.8% SiO2, 24.8% B2O3, 6.1% Al2O3, 5.7% Na2O, 3.5% K2O, and 0.1% MgO.

[0024] The composite pore-forming agent includes PMMA and alumina hollow spheres in a volume ratio of 2:7. The pore-forming principles of PMMA and alumina hollow spheres are different. After sintering, uniform pores are formed while maintaining the strength of the cutting head under the alumina hollow sphere structure. At the same time, it can effectively avoid microcracks formed inside the cutting head during the heating and degassing process.

[0025] The dispersants include styrene-maleic anhydride, ethanol, and deionized water. Polystyrene-maleic anhydride, as an important polymer, has unique rheological properties. When at rest, it exhibits high viscosity, which effectively prevents material sedimentation and stratification. However, when subjected to external stirring or shearing, the viscosity rapidly decreases, demonstrating good flowability. When dissolved in water, it ionizes to form anions, which are tightly adsorbed onto the surface of the dispersed particles, giving the particles the same charge. Due to the repulsion of like charges, electrostatic repulsion is formed, effectively preventing particle agglomeration and achieving dispersion. The steric hindrance effect of the polymer molecular chains also plays a crucial role. When the polymer molecules are adsorbed close to each other, the physical steric hindrance between the molecular chains prevents agglomeration. When adsorbed onto the surface of powder particles, it acts as a water-reducing agent without reducing the flowability of the slurry, ensuring the uniform dispersion of micro-powder while significantly shortening the subsequent drying process time.

[0026] Multi-functional modifiers include polycarboxylate superplasticizers, nano-neodymium oxide, and cerium oxide. Adding polycarboxylate superplasticizers to the mixed slurry effectively improves the dispersibility of the raw materials, allowing them to be more evenly distributed in the grinding wheel. Polycarboxylate superplasticizers can chemically react with the binder in the grinding wheel to form a more stable chemical bond structure. This chemical bond structure not only effectively improves the strength of the grinding wheel but also enhances its wear resistance and impact resistance, thereby extending its service life. The neodymium oxide component helps improve mechanical strength, and its high thermal conductivity effectively improves grinding conditions. The cerium oxide component helps improve the mechanical strength of the grinding wheel tip and also has a certain polishing auxiliary effect.

[0027] The lubricant, which includes graphite and molybdenum disulfide, helps to improve the material removal efficiency in grinding and cutting thin materials, and can extend the service life of the grinding wheel and improve the wear ratio.

[0028] This preparation method includes: S1. Weigh the composite abrasive, ceramic binder, composite pore-forming agent, dispersant, multi-effect modifier and lubricant according to the formula ratio; The steps for producing the ceramic binder are as follows: a1. Using a precision balance with an accuracy of not less than 1 mg, weigh SiO2, B2O3, Al2O3, Na2O, K2O and MgO according to the formula ratio; a2. After weighing, SiO2, B2O3, Al2O3, Na2O, K2O and MgO are poured into an alumina crucible in sequence and placed in a high-temperature furnace for firing at a temperature of 1650℃. a3. After reaching the firing temperature, keep it at that temperature for 2 hours, then pour the molten binder mixture into a metal bucket containing deionized water for water quenching. a4. The water-quenched binder is dried in an oven at a temperature of 60-80°C for 12 hours. a5. Pour the completely dried and dehydrated binder into the ball mill jar of the three-dimensional planetary ball mill for ball milling. Set the ball milling time to 4 hours. a6. After ball milling, the mixture is sieved three times using a 400-mesh sieve to obtain the ceramic binder. S2. Prepare mixed liquid A; b1. Pour the weighed dispersant, multi-effect modifier and lubricant into the ball mill jar of the three-dimensional planetary ball mill for ball milling and mixing. Set the ball milling time to 1 hour. b2. Add the powder after ball milling and mixing in step b1 to a solution of ethanol and deionized water. The total mass ratio of the mixed powder to the ethanol and deionized water solution is 1:15, and the ratio of ethanol to deionized water is 1:1. b3. Use an automated stirrer to stir the ethanol-water solution containing dispersant, multi-effect modifier and lubricant. Use a dispersing disc stirring paddle to stir and mix evenly to obtain mixture A. The stirring time is 60 min. S3. Prepare mixed liquid B; c1. Pour the weighed composite abrasive and ceramic binder into the ball mill jar of the three-dimensional planetary ball mill for ball milling and mixing. Use an agate jar and agate balls, and set the ball milling time to 1.5 hours. c2. Use a 400# sieve to sieve the ball-milled composite abrasive and ceramic binder mixture, repeating the sieve 3 times; c3. Pour the composite abrasive and ceramic binder from step c2 together with the composite pore-forming agent into mixed liquid A; c4. Use an automated mixer to stir for 1.5 hours to obtain mixed liquid B, using a dispersion disc type agitator. S4. Perform ultrasonic treatment, drying and sieving on the mixed liquid B; d1. Place the mixed liquid B into an ultrasonic vibrator for mixing and dispersion. Set the vibration frequency to 20 kHz and the ultrasonic vibration time to 1 hour. d2. Use an automated mixer to mix for 0.5 hours, using a dispersion disc type agitator. d3. Pour the mixture into a stainless steel tray and spread the liquid mixture B evenly in the stainless steel tray. Place the liquid mixture B in an 80℃ high-temperature oven for 6 hours to dry it and obtain the material. d4. Use a 400# sieve to sieve the material, collect the sieved material for later use, and repeat the sieving process 3 times. S5. Making the grinding wheel; e1. Weigh the material according to the material weight calculated based on the mold design volume. The number of material portions should be consistent with the number of cutting heads designed for the grinding wheel. e2. After cleaning the mold, put the weighed single portion of material into the mold cavity, cover it with a pressure plate, and press it in the press. Set the pressure to 8MPa and the time to 2min, and then demold the cutter head. e3. After all the cutting heads are pressed and demolded, they are buried in a ceramic box for sand treatment and then placed in a muffle furnace for sintering according to the set heating curve. e4. After the cutter head is sandblasted and the substrate is cleaned, the cutter head is bonded to the groove of the substrate using an epoxy resin adhesive, so that the spacing between each cutter head is equal and the side is perpendicular to the surface of the substrate. e5. After bonding, the grinding wheel tip end face is re-ground using a surface grinder.

[0029] The SiC ingot thinning grinding wheel prepared using this process can achieve a stable grinding and thinning process without grinding wheel tooth breakage when grinding a 6-inch SiC ingot. The wear ratio (ingot removal: grinding wheel wear) is >12:1, and the surface roughness Ra after grinding is <15nm.

[0030] Example 2 Please see Figure 2 As shown, the present invention provides a ceramic diamond grinding wheel technology solution for SiC thinning: the grinding wheel includes 25% composite abrasive, 30% ceramic binder, 35% composite pore-forming agent, 1.5% dispersant, 2% multi-effect modifier and 1.5% lubricant, wherein the composite abrasive is coated with diamond, boron carbide and silicon carbide, and the volume fraction ratio is 15:2:1, the diamond is preferably 8000#, the corresponding boron carbide is preferably 5000#, and the silicon carbide particle size is preferably 5000#. By combining superhard abrasive with relatively coarser and relatively low hardness abrasive, the dual guarantee of high surface quality and high removal efficiency for grinding and thinning is achieved. The main abrasive is diamond micro powder that has undergone degreasing, roughening, sensitization and activation pretreatment processes followed by nickel plating.

[0031] The ceramic binder comprises 55.2% SiO2, 22.5% B2O3, 9.8% Al2O3, 7.6% Na2O, 4.8% K2O, and 0.1% MgO.

[0032] The composite pore-forming agent includes PMMA and alumina hollow spheres in a volume ratio of 2:5. The pore-forming principles of PMMA and alumina hollow spheres are different. After sintering, uniform pores are formed while maintaining the alumina hollow sphere structure to ensure the strength of the cutting head. At the same time, it can effectively avoid microcracks formed inside the cutting head during the heating and degassing process.

[0033] The dispersants include styrene-maleic anhydride, ethanol, and deionized water. Polystyrene-maleic anhydride, as an important polymer, has unique rheological properties. When at rest, it exhibits high viscosity, which effectively prevents material sedimentation and stratification. However, when subjected to external stirring or shearing, the viscosity rapidly decreases, demonstrating good flowability. When dissolved in water, it ionizes to form anions, which are tightly adsorbed onto the surface of the dispersed particles, giving the particles the same charge. Due to the repulsion of like charges, electrostatic repulsion is formed, effectively preventing particle agglomeration and achieving dispersion. The steric hindrance effect of the polymer molecular chains also plays a crucial role. When the polymer molecules are adsorbed close to each other, the physical steric hindrance between the molecular chains prevents agglomeration. When adsorbed onto the surface of powder particles, it acts as a water-reducing agent without reducing the flowability of the slurry, ensuring the uniform dispersion of micro-powder while significantly shortening the subsequent drying process time.

[0034] Multi-functional modifiers include polycarboxylate superplasticizers, nano-neodymium oxide, and cerium oxide. Adding polycarboxylate superplasticizers to the mixed slurry effectively improves the dispersibility of the raw materials, allowing them to be more evenly distributed in the grinding wheel. Polycarboxylate superplasticizers can chemically react with the binder in the grinding wheel to form a more stable chemical bond structure. This chemical bond structure not only effectively improves the strength of the grinding wheel but also enhances its wear resistance and impact resistance, thereby extending its service life. The neodymium oxide component helps improve mechanical strength, and its high thermal conductivity effectively improves grinding conditions. The cerium oxide component helps improve the mechanical strength of the grinding wheel tip and also has a certain polishing auxiliary effect.

[0035] The lubricant, which includes graphite and molybdenum disulfide, helps to improve the material removal efficiency in grinding and cutting thin materials, and can extend the service life of the grinding wheel and improve the wear ratio.

[0036] This preparation method includes: S1. Weigh the composite abrasive, ceramic binder, composite pore-forming agent, dispersant, multi-effect modifier and lubricant according to the formula ratio; The steps for producing the ceramic binder are as follows: a1. Using a precision balance with an accuracy of not less than 1 mg, weigh SiO2, B2O3, Al2O3, Na2O, K2O and MgO according to the formula ratio; a2. After weighing, SiO2, B2O3, Al2O3, Na2O, K2O and MgO are poured into an alumina crucible in sequence and placed in a high-temperature furnace for firing at a temperature of 1650℃. a3. After reaching the firing temperature, keep it at that temperature for 2 hours, then pour the molten binder mixture into a metal bucket containing deionized water for water quenching. a4. The water-quenched binder is dried in an oven at a temperature of 60-80°C for 12 hours. a5. Pour the completely dried and dehydrated binder into the ball mill jar of the three-dimensional planetary ball mill for ball milling. Set the ball milling time to 4 hours. a6. After ball milling, the mixture is sieved three times using a 400-mesh sieve to obtain the ceramic binder. S2. Prepare mixed liquid A; b1. Pour the weighed dispersant, multi-effect modifier and lubricant into the ball mill jar of the three-dimensional planetary ball mill for ball milling and mixing. Set the ball milling time to 1 hour. b2. Add the powder after ball milling and mixing in step b1 to a solution of ethanol and deionized water. The total mass ratio of the mixed powder to the ethanol and deionized water solution is 1:20, and the ratio of ethanol to deionized water is 2:1. b3. Use an automated stirrer to stir the ethanol-water solution containing dispersant, multi-effect modifier and lubricant. Use a dispersing disc stirring paddle to stir and mix evenly to obtain mixture A. The stirring time is 60 min. S3. Prepare mixed liquid B; c1. Pour the weighed composite abrasive and ceramic binder into the ball mill jar of the three-dimensional planetary ball mill for ball milling and mixing. Use an agate jar and agate balls, and set the ball milling time to 1.5 hours. c2. Use a 400# sieve to sieve the ball-milled composite abrasive and ceramic binder mixture, repeating the sieve 3 times; c3. Pour the composite abrasive and ceramic binder from step c2 together with the composite pore-forming agent into mixed liquid A; c4. Use an automated mixer to stir for 1.5 hours to obtain mixed liquid B, using a dispersion disc type agitator. S4. Perform ultrasonic treatment, drying and sieving on the mixed liquid B; d1. Place the mixed liquid B into an ultrasonic vibrator for mixing and dispersion. Set the vibration frequency to 20 kHz and the ultrasonic vibration time to 1 hour. d2. Use an automated mixer to mix for 0.5 hours, using a dispersion disc type agitator. d3. Pour the mixture into a stainless steel tray and spread the liquid mixture B evenly in the stainless steel tray. Place the liquid mixture B in an 80℃ high-temperature oven for 6 hours to dry it and obtain the material. d4. Use a 400# sieve to sieve the material, collect the sieved material for later use, and repeat the sieving process 3 times. S5. Making the grinding wheel; e1. Weigh the material according to the material weight calculated based on the mold design volume. The number of material portions should be consistent with the number of cutting heads designed for the grinding wheel. e2. After cleaning the mold, put the weighed single portion of material into the mold cavity, cover it with a pressure plate, and press it in the press. Set the pressure to 6MPa and the time to 2min, and then demold the cutter head. e3. After all the cutting heads are pressed and demolded, they are buried in a ceramic box for sand treatment and then placed in a muffle furnace for sintering according to the set heating curve. e4. After the cutter head is sandblasted and the substrate is cleaned, the cutter head is bonded to the groove of the substrate using an epoxy resin adhesive, so that the spacing between each cutter head is equal and the side is perpendicular to the surface of the substrate. e5. After bonding, the grinding wheel tip end face is re-ground using a surface grinder.

[0037] The SiC ingot thinning grinding wheel prepared using this process can achieve a stable grinding and thinning process without grinding wheel tooth breakage when grinding a 6-inch SiC ingot. The wear ratio (ingot removal: grinding wheel wear) is >8:1, and the surface roughness Ra after grinding is <10nm.

[0038] Comparative Example 1 Please see Figure 3 As shown, another preparation method is provided: the grinding wheel includes 35% abrasive, 35% ceramic binder, 25% pore-forming agent, and 5% reserved natural pores, wherein the diamond in the abrasive is selected as 3000#, and the pore-forming agent is PMMA particles.

[0039] This preparation method includes: S1. Weigh out the abrasive, conventional ceramic binder and pore-forming agent according to the formula ratio; S2. Pour the weighed abrasive and ceramic binder into the ball mill jar of the three-dimensional planetary ball mill for ball milling and mixing. Set the ball milling time to 1.5 hours. S3. Use a 400# sieve to sieve the mixture of abrasive and ceramic binder after ball milling, and repeat the sieving process 3 times. S4. Add the sieved abrasive, ceramic binder and pore-forming agent to a solution of ethanol and deionized water. The total mass ratio of the mixed powder to the ethanol-water solution is 1:15, and the ratio of ethanol to deionized water is 1:1. S5. Use an automated mixer to mix for 1.5 hours, using a conventional blade-type agitator. S6. Pour the mixture into a stainless steel tray and spread it evenly on the stainless steel tray. Place it in an 80℃ high-temperature oven for 6 hours to dry the material. S7. Use a 400# sieve to sieve the material, take the sieved material for later use, and repeat the sieving process 3 times. S8. Weigh the material according to the material weight calculated based on the mold design volume. The number of material portions should be consistent with the number of cutting heads designed for the grinding wheel. S9. After cleaning the mold, put the weighed single portion of material into the mold cavity, cover it with a pressure plate, and press it in the press. Set the pressure to 8MPa and the time to 2min, and then demold the cutter head. S10. After all the cutting heads are pressed and demolded, they are buried in a ceramic box for sand treatment and then placed in a muffle furnace for sintering according to the set heating curve. S11. After the cutter head is sandblasted and the substrate is cleaned, the cutter head is bonded to the groove of the substrate using an epoxy resin adhesive, so that the spacing between each cutter head is equal and the side is perpendicular to the surface of the substrate. S12. After bonding, the end face of the grinding wheel tip is ground using a surface grinder.

[0040] The grinding wheel for thinning SiC ingots prepared using this process was used to grind 6-inch SiC ingots. The wear ratio and surface roughness results are as follows: Figure 3 As shown.

[0041] Comparative Example 2 Please see Figure 4 As shown, another preparation method is provided: the grinding wheel includes 25% abrasive, 35% ceramic binder, 35% pore-forming agent, and 5% natural pores, wherein the diamond in the abrasive is selected as 8000#, and the pore-forming agent is PMMA particles.

[0042] This preparation method includes: S1. Weigh out the abrasive, conventional ceramic binder and pore-forming agent according to the formula ratio; S2. Pour the weighed abrasive and ceramic binder into the ball mill jar of the three-dimensional planetary ball mill for ball milling and mixing. Set the ball milling time to 1.5 hours. S3. Use a 400# sieve to sieve the mixture of abrasive and ceramic binder after ball milling, and repeat the sieving process 3 times. S4. Add the sieved abrasive, ceramic binder and pore-forming agent to a solution of ethanol and deionized water. The total mass ratio of the mixed powder to the ethanol-water solution is 1:20, and the ratio of ethanol to deionized water is 2:1. S5. Use an automated mixer to mix for 1.5 hours, using a conventional blade-type agitator. S6. Pour the mixture into a stainless steel tray and spread it evenly on the stainless steel tray. Place it in an 80℃ high-temperature oven for 6 hours to dry the material. S7. Use a 400# sieve to sieve the material, take the sieved material for later use, and repeat the sieving process 3 times. S8. Weigh the material according to the material weight calculated based on the mold design volume. The number of material portions should be consistent with the number of cutting heads designed for the grinding wheel. S9. After cleaning the mold, put the weighed single portion of material into the mold cavity, cover it with a pressure plate, and press it in the press. Set the pressure to 6MPa and the time to 2min, and then demold the cutter head. S10. After all the cutting heads are pressed and demolded, they are buried in a ceramic box for sand treatment and then placed in a muffle furnace for sintering according to the set heating curve. S11. After the cutter head is sandblasted and the substrate is cleaned, the cutter head is bonded to the groove of the substrate using an epoxy resin adhesive, so that the spacing between each cutter head is equal and the side is perpendicular to the surface of the substrate. S12. After bonding, the end face of the grinding wheel tip is ground using a surface grinder.

[0043] The grinding wheel for thinning SiC ingots prepared using this process was used to grind 6-inch SiC ingots. The wear ratio and surface roughness results are as follows: Figure 4 As shown.

[0044] Based on the above Examples 1 and 2 and Comparative Examples 1 and 2, the grinding wheels manufactured according to the manufacturing method of the present invention show significant improvements in wear ratio and surface roughness in the SiC ingot thinning process, as shown in Table 1. Excellent surface quality after grinding and grinding wheel service performance are obtained, verifying the effectiveness and advantages of the manufacturing method in the present invention.

[0045] Table 1. Comparison of key indicators between examples and comparisons. Figure 1-4 The graph shows the results of 30 grinding tests, with the horizontal axis representing the test number. The triangles on the left vertical axis represent the wear ratio, and the circles on the right vertical axis represent surface roughness.

[0046] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A ceramic diamond grinding wheel for SiC thinning, characterized in that: The grinding wheel comprises 25%~35% composite abrasive, 30%~40% ceramic binder, 25%~35% composite pore-forming agent, 1%~1.5% dispersant, 2%~3% multi-effect modifier, and 1%~1.5% lubricant; The composite abrasive coating comprises diamond, boron carbide, and silicon carbide in a volume fraction ratio of 15:2:1; the ceramic binder comprises 55-75% SiO2, 22-28% B2O3, 6-10% Al2O3, 5-8% Na2O, 3-5% K2O, and 0.05-0.1% MgO; the composite pore-forming agent comprises PMMA and hollow alumina beads in a volume fraction ratio of 2:5-2:7; the dispersant comprises styrene-maleic anhydride, ethanol, and deionized water; the multi-effect modifier comprises polycarboxylate superplasticizer, nano-neodymium oxide, and cerium oxide; and the lubricant comprises graphite and molybdenum disulfide.

2. The method for preparing a ceramic diamond grinding wheel for SiC thinning according to claim 1, characterized in that: The preparation method specifically includes the following steps: S1. Weigh the composite abrasive, ceramic binder, composite pore-forming agent, dispersant, multi-effect modifier and lubricant according to the formula ratio; S2. Prepare mixed liquid A; S3. Prepare mixed liquid B; S4. Perform ultrasonic treatment, drying and sieving on the mixed liquid B; S5. Making a grinding wheel.

3. The method for preparing a ceramic diamond grinding wheel for SiC thinning according to claim 2, characterized in that: The method for preparing the ceramic binder in step S1 specifically includes the following steps: a1. Using a precision balance with an accuracy of not less than 1 mg, weigh SiO2, B2O3, Al2O3, Na2O, K2O and MgO according to the formula ratio; a2. After weighing, SiO2, B2O3, Al2O3, Na2O, K2O and MgO are poured into an alumina crucible in sequence and placed in a high-temperature furnace for firing at a temperature of 1650℃. a3. After reaching the firing temperature, keep it at that temperature for 2 hours, then pour the molten binder mixture into a metal bucket containing deionized water for water quenching. a4. The water-quenched binder is dried in an oven at a temperature of 60-80°C for 12 hours. a5. Pour the completely dried and dehydrated binder into the ball mill jar of the three-dimensional planetary ball mill for ball milling. Set the ball milling time to 4 hours. a6. After ball milling, the mixture is sieved three times using a 400-mesh sieve to obtain the ceramic binder for later use.

4. The method for preparing a ceramic diamond grinding wheel for SiC thinning according to claim 2, characterized in that: Step S2 specifically includes the following steps: b1. Pour the weighed dispersant, multi-effect modifier and lubricant into the ball mill jar of the three-dimensional planetary ball mill for ball milling and mixing. Set the ball milling time to 1~1.5 hours. b2. Add the powder after ball milling and mixing in step b1 to a solution of ethanol and deionized water. The total mass ratio of the mixed powder to the ethanol and deionized water solution is 1:15 to 1:20, and the ratio of ethanol to deionized water is 1:1 to 2:

1. b3. Use an automated stirrer to stir the ethanol aqueous solution containing dispersant, multi-effect modifier and lubricant. Use a dispersing disc stirring paddle to stir and mix evenly to obtain mixture A. The stirring time is 30min~60min.

5. The method for preparing a ceramic diamond grinding wheel for SiC thinning according to claim 2, characterized in that: Step S3 specifically includes the following steps: c1. Pour the weighed composite abrasive and ceramic binder into the ball mill jar of the three-dimensional planetary ball mill for ball milling and mixing. Use an agate jar and agate balls, and set the ball milling time to 1.5 hours. c2. Use a 400# sieve to sieve the ball-milled composite abrasive and ceramic binder mixture, repeating the sieve 3 times; c3. Pour the composite abrasive and ceramic binder from step c2 together with the composite pore-forming agent into mixed liquid A; c4. Use an automated mixer to stir for 1~1.5 hours to obtain mixed liquid B, using a dispersion disc agitator.

6. The method for preparing a ceramic diamond grinding wheel for SiC thinning according to claim 2, characterized in that: Step S4 specifically includes the following steps: d1. Place the mixed liquid B into an ultrasonic vibrator for mixing and dispersion. Set the vibration frequency to 20 kHz and the ultrasonic vibration time to 0.5 to 1 hour. d2. Use an automated mixer to mix for 0.5 hours, using a dispersion disc type agitator. d3. Pour the mixture into a stainless steel tray and spread the liquid mixture B evenly in the stainless steel tray. Place the liquid mixture B in an 80℃ high-temperature oven for 6 hours to dry it and obtain the material. d4. Use a 400# sieve to sieve the material, remove the sieved material for later use, and repeat the sieving process 3 times.

7. The method for preparing a ceramic diamond grinding wheel for SiC thinning according to claim 2, characterized in that: Step S5 specifically includes the following steps: e1. Weigh the material according to the material weight calculated based on the mold design volume. The number of material portions should be consistent with the number of cutting heads designed for the grinding wheel. e2. After cleaning the mold, put the weighed single portion of material into the mold cavity, cover it with a pressure plate, and press it in the press. Set the pressure to 6MPa~8MPa and the time to 2min, and then demold the cutter head. e3. After all the cutting heads are pressed and demolded, they are buried in a ceramic box for sand treatment and then placed in a muffle furnace for sintering according to the set heating curve. e4. After the cutter head is sandblasted and the substrate is cleaned, the cutter head is bonded to the groove of the substrate using an epoxy resin adhesive, so that the spacing between each cutter head is equal and the side is perpendicular to the surface of the substrate. e5. After bonding, the grinding wheel tip end face is re-ground using a surface grinder.

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