High-porosity ceramic bond diamond micro-powder grinding tool as well as preparation method and application thereof

Abstract

The invention provides a high-porosity ceramic bond diamond micro-powder grinding tool and a preparation method and application thereof. The preparation method comprises the following steps: preparing ceramic bond diamond micro-powder composite powder by adopting a sol-gel method; the preparation method comprises the following steps: preparing porous agglomerated diamond microspheres by taking ceramic bond diamond micro-powder composite powder and an organic pore-forming agent as raw materials and adopting an atomization granulation method; the preparation method comprises the following steps: taking sodium alginate and calcium salt as raw materials, and preparing a calcium alginate water ball solution by adopting a multiple emulsion method and an atomization granulation method; the porous agglomerated diamond microspheres and the calcium alginate water balls are used as main raw materials, and a gel casting method is adopted for preparing the ceramic bond diamond micro-powder grinding tool. According to the diamond micro-powder grinding tool, the organic pore forming agent and the sodium alginate water balls are used as the pore forming agents, so that the particle size and proportion of pores in the prepared diamond micro-powder grinding tool can be accurately controlled, and the diamond micro-powder grinding tool has the characteristics of high porosity, good self-sharpening performance, low grinding resistance and the like and can be used for efficient and high-quality machining of semiconductor materials.

Description

Technical Field

[0002] The present invention relates to the field of superhard materials, and particularly to a high-porosity ceramic-bonded diamond micropowder grinding tool, a preparation method thereof, and an application thereof. Background Art

[0003] Diamond micropowder is a new type of superhard and ultrafine abrasive formed by special processing of synthetic diamond single crystals. It is an ideal material for grinding and polishing high-hardness materials. Diamond micropowder has good toughness and can maintain a high grinding force during the grinding and polishing process without being easily scratched. It is widely used in the processing of hard and brittle materials.

[0004] Due to excellent properties such as long service life, good stability, and good self-sharpening ability, ceramic-bonded diamond grinding tools have been widely used in the field of processing semiconductor electronic workpieces, especially in the processing of second-generation semiconductor silicon wafers. At present, the application demand of ceramic binders in third-generation semiconductor silicon carbide is increasing day by day. However, diamond thinning wheels prepared by traditional manufacturing methods mainly have problems such as a short dressing cycle caused by poor self-sharpening ability of the grinding wheel, poor surface quality of the wafer, and high current values. The self-sharpening ability of the grinding wheel means that "after the abrasive grains are blunt, they will break or fall off under the action of grinding force and thermal shock, thereby forming new cutting edges and enabling the grinding wheel to maintain its grinding ability". Pores are an important part of ceramic-bonded diamond grinding wheels, and their size and porosity have an important impact on the processing performance of the grinding wheel. The pores in the grinding wheel can make the abrasive grains sharper and increase the grinding efficiency. When the grinding wheel rotates, the pores will suck in the surrounding air and discharge the dust inside, thus ensuring that the surface of the grinding wheel always remains clean. At the same time, these pores can carry away the grinding debris, facilitating the accumulation of grinding debris and the clogging of the grinding wheel. In addition, during the grinding process, frictional heat will be generated between the grinding wheel and the workpiece. Without the existence of pores, the temperature of the grinding area will rise, affecting the grinding efficiency and the service life of the grinding wheel. At present, the method of creating pores in ceramic-bonded diamond grinding wheels is by adding pore-forming agents. Since an excessive amount of pore-forming agent will cause the grinding wheel to agglomerate, turn black, and crack, it is difficult to prepare a high-porosity grinding wheel with high self-sharpening ability using this method.

[0005] Chinese Patent Application CN 111331527 A discloses an ultra-high porosity ceramic-bonded diamond superfine grinding tool and its preparation method. The method mainly uses the injection molding process, with a surfactant as a pore-forming agent combined with high-speed stirring and foaming to prepare the ultra-high porosity ceramic-bonded diamond superfine grinding tool. This method can solve the problems of black heart and cracking in traditional diamond grinding wheels, and can make the porosity in the grinding tool as high as more than 75%, significantly improving the grinding performance of the ceramic-bonded diamond superfine grinding tool. However, since the pore size and position prepared by the foaming method are randomly distributed, it is difficult to maintain the consistency of the grinding tool performance. Therefore, it is difficult to precisely control the pore size and proportion of the pores in the superfine grinding tool, and the grinding performance of the grinding tool and the processing quality of semiconductor wafers need to be further improved. Summary of the Invention

[0006] In view of this, to solve the above problems, the present invention provides a high-porosity ceramic-bonded diamond micropowder grinding tool, its preparation method and application. Using an organic pore-forming agent and sodium alginate water balls as pore-forming agents, the pore size and proportion of the pores in the prepared diamond micropowder grinding tool can be precisely controlled, with characteristics such as a high porosity, good self-sharpening property, and low grinding resistance, and can be used for the efficient and high-quality processing of semiconductor materials such as silicon carbide, silicon wafers, and gallium nitride.

[0007] Specifically, in the first aspect of the present invention, a high-porosity ceramic-bonded diamond micropowder grinding tool is provided, including a diamond micropowder grinding tool body, large pores closely and uniformly distributed in the diamond micropowder grinding tool body, and small pores distributed between adjacent large pores. Among them, the aperture of the large pores is 80 - 1000 μm, and the aperture of the small pores is 1.0 - 10 μm.

[0008] Furthermore, the raw materials of the ceramic-bonded diamond micropowder grinding tool include: porous aggregated diamond microspheres and calcium alginate water balls with a mass ratio of (1 - 5) : (5 - 15). Among them, the particle size of the porous aggregated diamond microspheres is 5 - 150 μm, and the porosity is 0 - 60%. Preferably, the mass ratio of the porous aggregated diamond microspheres to the calcium alginate water balls is (2 - 3) : (5 - 10).

[0009] The porous aggregated diamond microspheres are mainly prepared by an atomization granulation method using a ceramic-bonded diamond micropowder composite powder and an organic pore-forming agent as raw materials and sintering in a muffle furnace to remove the organic pore-forming agent. Among them, the mass ratio of the ceramic-bonded diamond micropowder composite powder to the organic pore-forming agent is (6 - 10) : (0 - 4), and the particle size of the organic pore-forming agent is not less than 1.0 μm. The raw materials of the ceramic-bonded diamond micropowder composite powder include 0 - 5 wt% of nano-fillers.

[0010] Preferably, the particle size of the organic pore former is 1.0 - 500 μm. Among them, the organic pore former with a particle size of 1.0 - 10 μm is mainly used as a small pore former to form small pores in the abrasive tool. The organic pore former with a particle size of 80 - 500 μm and the calcium alginate hydrosphere are used together as a large pore former to form large pores in the abrasive tool, so as to reduce or avoid the black heart problem during the manufacturing process of high porosity diamond micropowder abrasive tools.

[0011] To improve the precision of the diamond micropowder abrasive tool, the mass ratio of the ceramic binder diamond micropowder composite powder to the organic pore former is preferably (6 - 8) : (2 - 4), the particle size of the ceramic binder diamond micropowder composite powder is preferably 0.5 - 3 μm, and the particle size of the organic pore former is 1.0 - 10 μm.

[0012] To further improve the precision of the diamond micropowder abrasive tool, the proportion of the nano - filler is 0.5 - 5%, and the particle size of the nano - filler is 50 - 100 nm.

[0013] Furthermore, the raw materials of the ceramic binder diamond micropowder composite powder further include 40 - 60% of diamond micropowder, and the balance is the raw materials of the ceramic binder prepared by the sol - gel method. Among them, the raw materials of the ceramic binder prepared by the sol - gel method include boric acid and metal nitrates.

[0014] The raw materials of the calcium alginate hydrosphere include a sodium alginate solution with a mass percentage concentration of 1% - 5% and a calcium salt solution with a mass percentage concentration of 0.5% - 5%. Among them, the calcium salt is calcium chloride or calcium lactate. The particle size of the calcium alginate hydrosphere is 80 - 600 μm.

[0015] The second aspect of the present invention provides a preparation method of the above - mentioned ceramic binder diamond micropowder abrasive tool, including the steps: Preparing the ceramic binder diamond micropowder composite powder: The ceramic binder diamond micropowder composite powder is prepared by the sol - gel method. Among the raw materials of the ceramic binder diamond micropowder composite powder, the proportion of the nano - filler is 0 - 5%; Preparing the agglomerated diamond microspheres: Using the ceramic binder diamond micropowder composite powder and the organic pore former as raw materials, the porous agglomerated diamond microspheres are prepared by the atomization granulation method, where the mass ratio of the ceramic binder diamond micropowder composite powder to the organic pore former is (6 - 10) : (0 - 4); Preparing the calcium alginate hydrosphere: Using sodium alginate and calcium salt as raw materials, the calcium alginate hydrosphere solution is prepared by the multiple emulsion method and the atomization granulation method; Preparing the ceramic binder diamond micropowder abrasive tool: Using the porous agglomerated diamond microspheres and the calcium alginate hydrosphere as the main raw materials, the ceramic binder diamond micropowder abrasive tool is prepared by the gel - casting method.

[0016] The steps for preparing the agglomerated diamond microspheres include: first, mixing the ceramic-bonded diamond micro-powder composite powder and the organic pore-forming agent, and preparing a ceramic mixed slurry with a solid content of 25-40%; then placing the ceramic mixed slurry in an atomizing granulator for granulation, wherein the atomizing frequency is 30-50 Hz and the atomizing temperature is 180°C-230°C to obtain diamond micro-powder ceramic composite particles; and then performing a second sintering treatment on the diamond ceramic composite particles to obtain the porous agglomerated diamond microspheres.

[0017] The steps for preparing the calcium alginate hydrospheres include: dropping a sodium alginate solution with a mass percentage concentration of 1-5% into a calcium salt solution with a mass percentage concentration of 0.5-5% by using an atomizing nozzle or a dropper to prepare a calcium alginate hydrosphere solution.

[0018] The third aspect of the present invention provides an application of the above-mentioned ceramic-bonded diamond micro-powder abrasive tool in the processing of semiconductor materials. Among them, the semiconductor materials include sapphire, silicon wafer, silicon carbide wafer, gallium nitride wafer, etc. Preferably, the above-mentioned ceramic-bonded diamond micro-powder abrasive tool is applied in the grinding process of semiconductor materials.

[0019] Therefore, in the preparation process of the ceramic-bonded diamond micro-powder abrasive tool provided by the present invention, by combining the sol-gel method, the spray granulation method and the gel casting method, small pores are formed by the small-particle-size organic pore-forming agent, and large pores are formed by the large-particle-size organic pore-forming agent and the calcium alginate hydrospheres. By controlling the dosage and particle size of the organic pore-forming agent and the alginate spheres, the particle size and proportion of the pores in the prepared diamond micro-powder abrasive tool can be precisely controlled, so that the diamond micro-powder abrasive tool has a high porosity, and the porosity can reach more than 60%, and even can reach more than 75%. In addition, the nano-filler will not be removed during the process of multiple sintering treatments, but the hardness of the nano-filler is relatively low, and its shedding during subsequent grinding can reduce the holding force of the diamond micro-powder and increase the self-sharpening of the grinding wheel. In addition, due to the high porosity of the abrasive tool and reasonable particle size grading, the diamond micro-powder abrasive tool has a low grinding resistance.

[0020] In summary, the above-mentioned diamond micro-powder abrasive tool provided by the present invention has the characteristics of high porosity, good self-sharpening and low grinding resistance, and can be used for the efficient and high-quality processing of semiconductor materials such as single crystal silicon carbide, single crystal silicon, and single crystal gallium nitride. Description of the Drawings

[0021] Figure 1 It is the SEM image of the porous agglomerated diamond microspheres prepared in Example 1 of the present invention; Figure 2 It is the SEM image of the diamond grinding wheel provided in Example 1 of the present invention; Figure 3 SEM image of the diamond grinding wheel provided in Comparative Example 1; Figure 4 Phenomenon photo of the diamond grinding wheel provided in Comparative Example 2 during the preparation process. Detailed implementation manners

[0022] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0023] In the scope disclosed in the present invention, the endpoints and any values of the scope are not limited to the precise scope or value. These scopes or values should be understood to include values close to these scopes or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in the present invention.

[0024] In the present invention, unless otherwise specified and / or described, all numerical values related to the dosage, concentration, content, etc. of components or raw materials are "weight". If not specifically specified, the terms used in the present invention are all common terms in the art. For the preparation processes, test methods, etc. used in each implementation manner without special description, they are all conventional means well-known to those skilled in the art, and the raw materials and equipment used can be obtained from public commercial channels.

[0025] The present invention first in-situ prepares a ceramic-bonded diamond micropowder composite powder containing nano-fillers by the sol-gel method; then uses the ceramic-bonded diamond micropowder composite powder containing nano-fillers, organic pore-forming agents, etc. as raw materials, and uses the atomization granulation method to prepare spherical agglomerated diamond microspheres with high porosity; then first uses the multiple emulsion method and the atomization granulation method to prepare calcium alginate hydrospheres, and then uses the agglomerated diamond microspheres, calcium alginate hydrospheres, etc. as the main raw materials, and adopts the gel casting method to prepare a ceramic abrasive block, thereby preparing a ceramic-bonded diamond micropowder abrasive tool with high porosity; wherein, by controlling the dosage and particle size of the organic pore-forming agent and the alginate balls, the precise control of the pore size and proportion in the diamond micropowder abrasive tool can be achieved.

[0026] Specifically, the first aspect of the present invention provides a diamond micropowder grinding tool with a ceramic bond, which includes a diamond micropowder grinding tool body, large pores closely and evenly distributed in the diamond micropowder grinding tool body, and small pores distributed between adjacent large pores. The aperture of the large pores is 80 - 1000 μm, and the aperture of the small pores is 1.0 - 10 μm. Both the large pores and the small pores are closed pores. Among them, to further improve the precision of the diamond micropowder grinding tool with a ceramic bond, the aperture of the large pores is 200 - 800 μm, and the aperture of the small pores is 1.8 - 5 μm.

[0027] The raw materials of the diamond micropowder grinding tool with a ceramic bond include: porous agglomerated diamond microspheres and calcium alginate hydrospheres with a mass ratio of (1 - 5) : (5 - 15). Among them, the particle size of the porous agglomerated diamond microspheres is 5 - 150 μm, and the porosity is 0 - 60%.

[0028] To further improve the precision of the diamond micropowder grinding tool with a ceramic bond, the particle size of the porous agglomerated diamond microspheres is 15 - 100 μm. To obtain a high-precision grinding wheel, the particle size of the porous agglomerated diamond microspheres is preferably 20 - 70 μm.

[0029] The porous agglomerated diamond microspheres are mainly prepared by an atomization granulation method using a diamond micropowder composite powder with a ceramic bond and an organic pore-forming agent as raw materials and sintering in a muffle furnace to remove the organic pore-forming agent. Among them, the mass ratio of the diamond micropowder composite powder with a ceramic bond to the organic pore-forming agent is (6 - 10) : (0 - 4), such as 6:4, 6.5:3.5, 7:3, 7.5:2.5, 8:2, 8.5:1.5, 9:1, 9.5:0.5, 10:0, etc. The particle size of the organic pore-forming agent is not less than 1.0 μm. The organic pore-forming agent can be PMMA microspheres, PS microspheres, etc.

[0030] In one embodiment, the organic pore-forming agent is mainly used to form small pores in the grinding tool and serves as a small-pore pore-forming agent. Preferably, the particle size of the organic pore-forming agent is 1.0 - 10 μm.

[0031] In another embodiment, the particle size of the organic pore-forming agent is 1.0 - 500 μm. A part of the organic pore-forming agent serves as a small-pore pore-forming agent, and the other part and the calcium alginate hydrospheres together serve as a large-pore pore-forming agent to form large pores in the grinding tool, so as to reduce or avoid the black core problem during the manufacturing process of the high-porosity diamond micropowder grinding tool; preferably, the organic pore-forming agent includes small-particle-size organic pore-forming agents with a particle size of 1.0 - 10 μm and large-particle-size organic pore-forming agents with a particle size of 80 - 500 μm.

[0032] To further improve the precision of the diamond micropowder abrasive tool, the mass ratio of the ceramic-bonded diamond micropowder composite powder to the organic pore-forming agent is preferably (6-8):(2-4), the particle size of the ceramic-bonded diamond micropowder composite powder is preferably 0.5-3 μm, and the particle size of the organic pore-forming agent is 1.0-10 μm.

[0033] The raw materials of the ceramic-bonded diamond micropowder composite powder include 0-5 wt% of nano-fillers. To further improve the precision of the diamond micropowder abrasive tool, the proportion of the nano-fillers is 0.5-5 wt%, and the particle size of the nano-fillers is 50-100 nm. The nano-fillers will not be removed during multiple sintering processes, but due to their low hardness, they can reduce the holding force of the diamond micropowder and increase the self-sharpening of the grinding wheel. Therefore, the nano-fillers include at least one of nano-carbon powder, nano-graphite powder, nano-hexagonal boron nitride, etc.

[0034] The raw materials of the ceramic-bonded diamond micropowder composite powder also include 40-60 wt% of diamond micropowder, and the balance is the raw materials of the ceramic binder prepared by the sol-gel method. The D50 particle size of the diamond micropowder is 30-1500 nm, such as 30 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500 nm, etc. The raw materials of the ceramic binder prepared by the sol-gel method include boric acid and metal nitrates. Specifically, the raw materials of the ceramic binder include orthosilicate esters, boric acid and metal nitrates. The metal nitrates are nitrates corresponding to the metal elements in the ceramic binder, such as sodium nitrate, potassium nitrate, calcium nitrate, zinc nitrate, barium nitrate, magnesium nitrate, zirconium nitrate, lithium nitrate, etc. The orthosilicate esters include ethyl orthosilicate, methyl orthosilicate, etc.

[0035] In one embodiment, the raw materials of the ceramic binder, by mass, include: 200 - 300 g of tetraethyl orthosilicate, 50 - 80 g of boric acid, 30 - 50 g of aluminum nitrate nonahydrate, 50 - 90 g of sodium nitrate, 5 - 10 g of potassium nitrate, 5 - 15 g of calcium nitrate tetrahydrate, 5 - 15 g of zinc nitrate hexahydrate, 5 - 15 g of magnesium nitrate hexahydrate, 5 - 15 g of barium nitrate, 5 - 10 g of lithium nitrate, and 5 - 10 g of zirconium nitrate. Among them, the raw materials of the ceramic binder further include 3 - 5 g of acetylacetone, 1 - 3 g of dispersant, and 10 - 15 ml of pH regulator. The dispersant is one or more of sodium dodecylbenzenesulfonate, cetylammonium chloride, sodium hexametaphosphate, sodium pyrophosphate, cetylammonium chloride, polyoxyethylene ether, etc. The pH regulator is nitric acid, hydrochloric acid, ammonia water, etc.

[0036] The main function of the calcium alginate water spheres is to form large pores on the diamond micropowder abrasive tool body. The calcium alginate water spheres are soft spheres, and during subsequent use, although they may be deformed by extrusion or two adjacent water spheres may stick together, they basically do not break. The particle size of the calcium alginate water spheres is 80 - 600 μm. Preferably, the particle size of the calcium alginate water spheres is 100 - 550 μm. To further improve the precision of the diamond micropowder abrasive tool, the calcium alginate water spheres are composed of different particle sizes, including 80 - 250 μm and 270 - 550 μm. The main raw materials of the calcium alginate water spheres are sodium alginate and calcium salts, and they are prepared by the multiple emulsion method and the atomization granulation method. Among them, the calcium salts are calcium chloride, calcium lactate, calcium nitrate, etc. The raw materials of the calcium alginate water spheres include a sodium alginate solution with a mass percentage concentration of 1% - 5% and a calcium salt solution with a mass percentage concentration of 0.5% - 5%. The dosages of the sodium alginate solution and the calcium salt solution affect the dosage of the calcium alginate water spheres. The concentration of the sodium alginate solution can be 1%, 1.5%, 2%, 3%, 3.5%, 4%, 4.5%, 5%, etc. The concentration of the calcium salt can be 0.5%, 1%, 1.5%, 2%, 3%, 3.5%, 4%, 4.5%, 5%, etc. Preferably, the raw materials of the calcium alginate water spheres include a sodium alginate solution with a mass percentage concentration of 1.5 - 2% and a calcium salt solution with a mass percentage concentration of 1% - 2%.

[0037] Further, the raw materials of the ceramic bond diamond micropowder abrasive tool further include: an amide mixture with a concentration of 3-10 wt%, an initiator solution with a concentration of 10-15 wt%, and a catalyst solution with a concentration of 0.5-2 wt%. The amide mixture includes N,N-methylenebisacrylamide and acrylamide with a mass ratio of 0.5-1:25-29, such as 0.5:29, 0.5:25, 0.5:27, 0.5:28, 1:25, 1:26, 1:27, 1:28, 1:29, etc. The concentration of the amide mixture can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc. The initiator can be a common initiator such as ammonium persulfate, and the concentration of the initiator solution can be 10%, 11%, 12%, 13%, 14%, 15%, etc. The catalyst can be N,N,N',N'-tetramethylethylenediamine, etc., and the concentration of the catalyst can be 0.5%, 0.8%, 1.0%, 1.2%, 1.5%, etc.

[0038] The second aspect of the present invention provides a method for preparing the above-mentioned ceramic bond diamond micropowder abrasive tool, including the steps: Preparing a ceramic bond diamond micropowder composite powder: Using the sol-gel method to prepare a ceramic bond diamond micropowder composite powder. Among the raw materials of the ceramic bond diamond micropowder composite powder, the proportion of nano-fillers is 0-5%; Preparing agglomerated diamond microspheres: Using the ceramic bond diamond micropowder composite powder and an organic pore-forming agent as raw materials, and using the atomization granulation method to prepare agglomerated diamond microspheres. The mass ratio of the ceramic bond diamond micropowder composite powder to the organic pore-forming agent is (6-10):(0-4); Preparing calcium alginate hydrospheres: Using sodium alginate and calcium salts as raw materials, and using the multiple emulsion method and the atomization granulation method to prepare a calcium alginate hydrosphere solution; Preparing a ceramic bond diamond micropowder abrasive tool: Using the porous agglomerated diamond microspheres and calcium alginate hydrospheres as the main raw materials, and using the gel casting method to prepare a ceramic bond diamond micropowder abrasive tool.

[0039] The step of preparing the ceramic bond diamond micropowder composite powder includes: first preparing a ceramic bond diamond gel containing nano-fillers, and then performing a first sintering treatment on the ceramic bond diamond gel containing nano-fillers, and ball milling to obtain the ceramic bond diamond micropowder composite powder.

[0040] The steps of the first sintering treatment include: first drying the diamond gel of the ceramic binder containing nano-fillers, and then sintering at 480 °C to 550 °C for 4 to 8 h to obtain a calcined product of the diamond of the ceramic binder; using a three-dimensional mixer to perform ball milling on the calcined product of the diamond of the ceramic binder to obtain a composite powder of diamond micro-powder of the ceramic binder with a particle size of 1 to 3 μm. Among them, the drying temperature of the diamond gel of the ceramic binder containing nano-fillers is 120 to 180 °C, and the drying time is 20 to 36 h.

[0041] In one embodiment, the steps of preparing the diamond gel of the ceramic binder containing nano-fillers include: Mix 50 to 100 g of diamond micro-powder, 200 to 300 g of tetraethyl orthosilicate, 500 to 800 ml of anhydrous ethanol solution, 3 to 5 g of acetylacetone chelating agent, 1 to 3 g of dispersant, 10 to 15 ml of pH regulator, and 0 to 100 g of nano-fillers with a particle size of 20 to 300 nm evenly by ultrasonic mechanical stirring for 30 to 60 min to obtain a sol solution A; Dissolve 50 to 80 g of boric acid, 30 to 50 g of aluminum nitrate nonahydrate, 50 to 90 g of sodium nitrate, 5 to 10 g of potassium nitrate, 5 to 15 g of calcium nitrate tetrahydrate, 5 to 15 g of zinc nitrate hexahydrate, 5 to 15 g of magnesium nitrate hexahydrate, 5 to 15 g of barium nitrate, 5 to 10 g of lithium nitrate, and 5 to 10 g of zirconium nitrate in a mixed solution of anhydrous ethanol and deionized water until completely dissolved to form a uniformly mixed salt mixture B.

[0042] Place the sol solution A in a water bath and stir at 60 °C to 80 °C. Add the salt mixture B to the sol solution A in 3 to 5 portions and stir until the sol solution A turns into a gel, and then let it stand at room temperature for 20 to 36 h to obtain the diamond gel of the ceramic binder containing nano-fillers.

[0043] The steps of preparing the agglomerated diamond microspheres include: first mixing the composite powder of the diamond micro-powder of the ceramic binder and the organic pore-forming agent, and preparing a ceramic mixed slurry according to a solid content of 25 to 40%; then performing atomization granulation on the ceramic mixed slurry to obtain diamond ceramic composite particles; and then performing a second sintering treatment on the diamond ceramic composite particles to obtain porous agglomerated diamond microspheres with a particle size of 5 to 150 μm.

[0044] The steps of the atomization granulation treatment include: placing the ceramic mixed slurry in an atomization granulator for granulation, where the atomization frequency is 30 to 50 Hz and the atomization temperature is 180 °C to 230 °C to obtain diamond ceramic composite particles with a particle size of 10 to 150 μm.

[0045] The steps of the second sintering treatment include: placing the diamond ceramic composite particles in a muffle furnace, keeping them at 300°C to 350°C for 1.5 to 3 h first, and then at 580°C to 630°C for 1.5 to 3 h to obtain porous agglomerated diamond microspheres with a size of 10 to 100 μm.

[0046] The steps of preparing the calcium alginate hydrospheres include: dropping a sodium alginate solution with a mass percentage concentration of 1 to 5% into a calcium salt solution with a mass percentage concentration of 0.5 to 5% using an atomizing nozzle or a dropper to prepare a calcium alginate hydrosphere solution, and the particle size of the calcium alginate hydrospheres therein is 80 to 600 μm. Among them, the particle size of the calcium alginate hydrospheres can be controlled and adjusted by the rotation speed of the atomizing nozzle or the aperture of the dropper orifice.

[0047] The steps of preparing the ceramic-bonded diamond micropowder grinding tool include: using the porous agglomerated diamond microspheres, calcium alginate hydrospheres, N,N'-methylenebisacrylamide, acrylamide, initiator and catalyst as raw materials, and preparing the ceramic-bonded diamond micropowder grinding tool by the gel-casting method. The steps of preparing the ceramic-bonded diamond micropowder grinding tool specifically include: first, uniformly mixing the acrylamide and N,N'-methylenebisacrylamide to prepare an amide mixed solution with a mass percentage concentration of 3 to 10 wt%, and then uniformly mixing 30 to 50 ml of the amide mixed solution, 10 to 50 g of the porous agglomerated diamond microspheres and 50 to 150 g of the calcium alginate hydrosphere solution to form a diamond microsphere mixed slurry; First, add 2 to 5 g of an initiator solution with a concentration of 10 to 15 wt% and 1 to 3 g of a catalyst solution with a concentration of 0.5 to 2 wt% to the diamond microsphere mixed slurry, and stir evenly to form a blank slurry; then pour the blank slurry into a mold, and perform freeze-drying treatment to make it completely dry, and demold to obtain a diamond micropowder grinding tool blank; Perform a third sintering treatment on the diamond micropowder grinding tool blank to obtain a ceramic-bonded diamond micropowder grinding tool.

[0048] Among them, the mold is made of materials such as acrylic plates, glass plates, ceramics, etc.

[0049] The steps of the third sintering treatment include: first placing the diamond micropowder grinding tool blank in a muffle furnace, sintering at 600°C to 700°C for 2 to 3 h, then cutting and bonding it in a grinding wheel matrix according to the grinding wheel drawing, and after correction, a diamond micropowder grinding tool product can be obtained.

[0050] The third aspect of the present invention provides an application of the above-mentioned diamond micropowder grinding tool with ceramic bond in the processing of semiconductor materials. Among them, the semiconductor materials include sapphire, silicon wafers, silicon carbide wafers, etc. Preferably, the application of the above-mentioned diamond micropowder grinding tool with ceramic bond in the grinding process of semiconductor materials, for example, the above-mentioned diamond micropowder grinding tool with ceramic bond can be used as a silicon carbide thinning grinding wheel for the thinning processing of silicon carbide wafers.

[0051] Therefore, in the preparation process of the diamond micropowder grinding tool with high-porosity ceramic bond provided by the present invention, a sol-gel method is used to prepare a ceramic bond diamond micropowder composite powder containing nano-fillers. The nano-fillers will not be removed during the process of multiple sintering treatments. However, the hardness of the nano-fillers is relatively low, and their shedding during subsequent grinding can reduce the holding force of the diamond micropowder, increase the self-sharpening of the grinding tool, and is beneficial to reducing the grinding resistance of the diamond micropowder grinding tool, improving the processing efficiency and processing quality. The present invention uses a spray granulation method to prepare agglomerated diamond microspheres from the ceramic bond diamond micropowder composite powder and an organic pore-forming agent, and uses the organic pore-forming agent to pre-pore. Then, combined with the multiple emulsion method and the atomization granulation method, calcium alginate hydrospheres are prepared. Using the agglomerated diamond microspheres and calcium alginate hydrospheres as the main raw materials, a diamond micropowder grinding tool is prepared by a gel-casting method. Among them, the calcium alginate hydrospheres are used as macroporous pore-forming agents. Combining with the pre-pore of the organic pore-forming agent can avoid the problem of difficult volatilization when directly adding an organic pore-forming agent in the prior art, such as blackening and cracking. The calcium alginate hydrospheres can avoid the problems of cracking and high-carbon difficult emission of the diamond micropowder grinding tool, making the diamond micropowder grinding tool with ceramic bond have a relatively high porosity, and the porosity can reach more than 60%, and even can reach more than 75%. Among them, by controlling the particle size and dosage of the small-particle-size organic pore-forming agent, the particle size and distribution density of the small pores in the diamond micropowder grinding tool can be controlled. By controlling the particle size and dosage of the calcium alginate hydrospheres and the large-particle-size organic pore-forming agent, the particle size and distribution density of the large pores in the diamond micropowder grinding tool can be controlled, so as to achieve precise control of the particle size and proportion of the pores in the diamond micropowder grinding tool. This method is still applicable to the preparation of other high-porosity ceramics.

[0052] In the diamond micropowder grinding tool with ceramic bond provided by the present invention, the large pores and small pores are evenly distributed, and the high porosity makes the contact surface between the workpiece and the grinding tool smaller, so the diamond micropowder grinding tool has a relatively low grinding resistance. Therefore, using the diamond mold provided by the present invention can achieve efficient and high-quality processing of semiconductor materials such as single-crystal silicon carbide.

[0053] The technical solutions of the present invention will be further described in detail below with reference to the embodiments. For the process parameters not specified in the embodiments, they are usually in accordance with the conventional conditions.

[0054] Example 1 This embodiment provides a high-porosity ceramic-bonded diamond micropowder grinding wheel and a preparation method thereof. The preparation method includes the following steps: Prepare sol solution A: Weigh 50 g of diamond micropowder with a D50 particle size of 500 nm and place it in a solution containing 200 g of tetraethyl orthosilicate and 700 ml of absolute ethanol. Then add 5 g of acetylacetone, 3 g of sodium dodecylbenzenesulfonate, 12 ml of nitric acid, and 10 g of 100-nm nanocarbon powder. Stir the mixture evenly by ultrasonic mechanical stirring for 45 min to obtain sol solution A; Prepare salt mixture B: Weigh 50 g of boric acid, 30 g of aluminum nitrate nonahydrate, 60 g of sodium nitrate, 7 g of potassium nitrate, 8 g of calcium nitrate tetrahydrate, 7 g of zinc nitrate hexahydrate, 7 g of magnesium nitrate hexahydrate, 7 g of barium nitrate, 7 g of lithium nitrate, and 7 g of zirconium nitrate and dissolve them in a mixed solution of absolute ethanol and deionized water. Mix them evenly until completely dissolved to obtain salt mixture B; Prepare ceramic-bonded diamond micropowder gel: Place the sol solution A in a magnetic stirring water bath and stir at 70 °C. Add the salt mixture B to the sol solution A in 5 portions and stir until the solution turns into a gel. Then let it stand at room temperature for 24 h to obtain ceramic-bonded diamond gel; Prepare ceramic-bonded diamond micropowder composite powder: Dry the ceramic-bonded diamond gel in an oven for 24 h at a drying temperature of 180 °C; then calcine the dried powder in a muffle furnace at 500 °C for 6 h to obtain a ceramic-bonded diamond calcined product; then use a three-dimensional mixer to ball-mill the ceramic-bonded diamond micropowder calcined product to 2 μm to obtain ceramic-bonded diamond micropowder composite powder; Prepare diamond micropowder ceramic composite particles: First, mix the ceramic-bonded diamond composite powder with PMMA microspheres with a particle size of 1 - 5 μm according to a mass ratio of 7:3, and then prepare a ceramic mixed slurry according to a solid content of 30%; Use an atomization granulator to granulate the ceramic mixed slurry. The frequency of the atomizer is 50 Hz, and the internal temperature of the cavity is 200 °C to obtain diamond ceramic composite particles with a particle size of 25 - 60 μm; Prepare agglomerated diamond microspheres: Place the diamond ceramic composite particles in a muffle furnace for calcination, keep them at 320 °C and 600 °C for 2 h respectively, to obtain Figure 1 the porous agglomerated diamond microspheres with a particle size of 20 - 50 μm as shown. Multiple micropores are evenly distributed in the porous agglomerated diamond microspheres, and the pore diameter of the micropores is concentrated in the range of 1 - 5 μm; Preparation of calcium alginate hydrospheres: Weigh 2 g of sodium alginate and dissolve it in 98 g of deionized water to prepare a 2% sodium alginate solution. Weigh 2 g of calcium lactate to prepare a 2% calcium chloride solution. Use an atomizing nozzle to drop the sodium alginate solution into the calcium lactate solution to prepare calcium alginate microspheres. Sieve out calcium alginate hydrospheres with particle sizes of 250 μm and 500 μm through a sieve, and the mass ratio of the two particle sizes of calcium alginate hydrospheres is 1:1; Preparation of diamond grinding wheel blank: Weigh acrylamide and N,N - methylenebisacrylamide according to a mass ratio of 29:1, and prepare an amide mixed solution with a mass fraction of 4%. Weigh 50 ml of the amide mixed solution, add 30 g of the porous agglomerated diamond microspheres and 90 g of the calcium alginate hydrospheres, and stir evenly to form a diamond microsphere mixed slurry. Take 3.5 g of an ammonium persulfate solution with a mass percentage content of 12.5% and 2 g of a 1% tetramethylethylenediamine solution, add them to the above - mentioned diamond microsphere mixed slurry, stir evenly to form a blank slurry. Pour the blank slurry into a glass mold, and dry it in a freeze - dryer for more than 48 h until it is completely dry, then demold to obtain a diamond grinding wheel blank; Preparation of diamond micropowder grinding wheel: Place the diamond grinding wheel blank in a muffle furnace, sinter it at 650 °C for 2.5 h, then cut and bond it in a grinding wheel base according to the grinding wheel drawing, and obtain a diamond grinding wheel product after correction. The SEM image of the diamond grinding wheel product is as Figure 2 shown. The diamond grinding wheel includes a diamond grinding wheel body, large pores closely distributed on the diamond grinding wheel body, and small pores formed between adjacent large pores. Among them, the aperture of the large pores is 250 - 900 μm, and the aperture of the small pores is 1 - 5 μm.

[0055] Example 2 This example provides a high - porosity ceramic - bonded diamond micropowder grinding wheel and its preparation method, including the steps: Preparation of sol solution A: Weigh 80 g of diamonds with a D50 particle size of 800 nm and place them in a solution containing 250 g of tetraethyl orthosilicate and 600 ml of absolute ethanol, and add 4.5 g of acetylacetone, 3 g of sodium hexametaphosphate, 12 ml of nitric acid, and 10 g of 150 - nm nano - graphite powder. Stir evenly by ultrasonic mechanical stirring for 45 min to obtain sol solution A; Preparation of salt mixture B: Weigh 65 g of boric acid, 40 g of aluminum nitrate nonahydrate, 60 g of sodium nitrate, 7 g of potassium nitrate, 8 g of calcium nitrate tetrahydrate, 7 g of zinc nitrate hexahydrate, 8 g of magnesium nitrate hexahydrate, 8 g of barium nitrate, 7 g of lithium nitrate, and 7 g of zirconium nitrate, dissolve them in a mixed solution of absolute ethanol and deionized water, and mix evenly until completely dissolved to obtain salt mixture B; Preparation of ceramic-bonded diamond gel: The steps are the same as those in Example 1; Preparation of ceramic-bonded diamond micropowder composite powder: The steps are basically the same as those in Example 1. The main differences are as follows: The drying temperature is 150 °C, the sintering temperature is 520 °C, and the ceramic-bonded diamond micropowder composite powder with a particle size of 1 μm is obtained by ball milling; Preparation of diamond ceramic composite particles: The steps are basically the same as those in Example 1. The main differences are as follows: PS microspheres with a size of 5-8 μm are used as the organic pore-forming agent, and the frequency of the atomizer is 40 Hz to obtain diamond ceramic composite particles with a particle size of 30-80 μm; Preparation of agglomerated diamond microspheres: The diamond ceramic composite particles are placed in a muffle furnace for calcination, and kept at 320 °C and 600 °C for 2 h respectively to obtain porous agglomerated diamond microspheres with a particle size of 40-50 μm; Preparation of calcium alginate hydrospheres: The steps are basically the same as those in Example 1. The main differences are as follows: The concentrations of the sodium alginate solution and the calcium chloride solution are both 1.5%. After sieving, calcium alginate hydrospheres with particle sizes of 100 μm and 300 μm are obtained, and the mass ratio of the two particle sizes of calcium alginate hydrospheres is 3:1; Preparation of diamond grinding wheel blank: Weigh acrylamide and N,N-methylenebisacrylamide according to a mass ratio of 27:0.8, and prepare an amide mixed solution with a mass fraction of 7%; Weigh 40 ml of the amide mixed solution, add 20 g of the porous agglomerated diamond microspheres and 50 g of the calcium alginate hydrospheres, and stir evenly to form a diamond microsphere mixed slurry; Take 5 g of an ammonium persulfate solution with a mass percentage content of 12.5% and 2 g of a 1.5% tetramethylethylenediamine solution, add them to the above diamond microsphere mixed slurry, stir evenly, and form a blank slurry; Pour the blank slurry into a glass mold, dry it in a freeze dryer for more than 48 h until it is completely dry, and demold to obtain a diamond grinding wheel blank; Preparation of diamond grinding wheel: The steps are basically the same as those in Example 1. Finally, a diamond grinding wheel product is obtained. The main difference between this diamond grinding wheel and the diamond grinding wheel provided in Example 1 is that the pore diameters of the large pores in it are concentrated in the range of 100-550 μm, and the small pores are concentrated in the range of 5-8 μm.

[0056] Example 3 This example provides a high-porosity ceramic-bonded diamond micropowder grinding wheel and a preparation method thereof, including the steps: Preparation of sol solution A: Weigh 100 g of diamond with a D50 particle size of 1200 nm and place it in a solution containing 300 g of tetraethyl orthosilicate and 800 ml of absolute ethanol. Then add 3 g of acetylacetone, 3 g of polyoxyethylene ether, 15 ml of hydrochloric acid, and 10 g of nano - hexagonal boron nitride with a particle size of 300 nm. Stir evenly by ultrasonic mechanical stirring for 45 min to obtain sol solution A; Preparation of salt mixture B: Weigh 80 g of boric acid, 50 g of aluminum nitrate nonahydrate, 90 g of sodium nitrate, 10 g of potassium nitrate, 12 g of calcium nitrate tetrahydrate, 7 g of zinc nitrate hexahydrate, 8 g of magnesium nitrate hexahydrate, 8 g of barium nitrate, 7 g of lithium nitrate, and 7 g of zirconium nitrate, and dissolve them in a mixed solution of absolute ethanol and deionized water. Mix evenly until completely dissolved to obtain salt mixture B; Preparation of ceramic - bonded diamond gel: The steps are the same as those in Example 1; Preparation of ceramic - bonded diamond micro - powder composite powder: The steps are basically the same as those in Example 1. The main differences are as follows: The drying temperature is 150 °C, the sintering temperature is 500 °C, and ceramic - bonded diamond micro - powder composite powder with a particle size of 3 μm is obtained by ball - milling; Preparation of diamond - ceramic composite particles: The steps are basically the same as those in Example 1. The main differences are as follows: PS microspheres with a particle size of 4 - 8 μm are used as organic pore - forming agents, and the frequency of the atomizer is 40 Hz to obtain diamond - ceramic composite particles with a particle size of 70 - 110 μm; Preparation of agglomerated diamond microspheres: Place the diamond - ceramic composite particles in a muffle furnace for calcination, keep them at 320 °C and 600 °C for 2 h respectively to obtain agglomerated diamond microspheres with a particle size of 70 - 100 μm; Preparation of calcium alginate hydrospheres: The steps are basically the same as those in Example 1. The main differences are as follows: The concentrations of sodium alginate solution and calcium chloride solution are both 1.5%. Screen to obtain calcium alginate hydrospheres with particle sizes of 200 μm and 400 μm, and the mass ratio of the two particle - size calcium alginate hydrospheres is 1:3; Preparation of diamond grinding wheel blank: Weigh acrylamide and N, N - methylenebisacrylamide according to a mass ratio of 25:0.8, and prepare an amide mixed solution with a mass fraction of 7%. Weigh 40 ml of the amide mixed solution, add 20 g of the above - mentioned agglomerated diamond microspheres and 50 g of calcium alginate hydrospheres, and stir evenly to form a diamond microsphere mixed slurry. Take 5 g of an ammonium persulfate solution with a mass percentage content of 12.5% and 2 g of a 1.5% tetramethylethylenediamine solution, add them to the above - mentioned diamond microsphere mixed slurry, stir evenly, and then form a blank slurry. Pour the blank slurry into a glass mold, dry it in a freeze - dryer for more than 48 h until it is completely dry, and demold to obtain a diamond grinding wheel blank; Preparation of diamond grinding wheel: The steps are basically the same as those in Example 1. Finally, a diamond grinding wheel product is obtained. The main difference between this diamond grinding wheel and the diamond grinding wheel provided in Example 1 is that the pore diameter of the large pores therein is concentrated in the range of 200 - 750 μm, and the small pores are concentrated in the range of 4 - 8 μm.

[0057] Example 4 This example provides a ceramic-bonded diamond grinding wheel and its preparation method, which are basically the same as those of the diamond grinding wheel and its preparation method provided in Example 1. The main difference is that: in this example, no nano-filler is added in the step of "preparing sol solution A", and the remaining steps and parameters are the same.

[0058] Example 5 This example provides a ceramic-bonded diamond grinding wheel and its preparation method, which are basically the same as those of the diamond grinding wheel and its preparation method provided in Example 1. The main difference is that: in this example, no organic pore-forming agent is added in the step of "preparing diamond ceramic composite particles", and the remaining steps and parameters are the same.

[0059] Comparative Example 1 This comparative example provides a ceramic-bonded diamond grinding wheel and its preparation method, which are basically the same as those of the diamond grinding wheel and its preparation method provided in Example 1. The main difference is that: in this example, no nano-filler is added in the step of "preparing sol solution A", the step of "preparing calcium alginate hydrospheres" is omitted, and no calcium alginate hydrospheres are added in "preparing the diamond grinding wheel blank". The pore diameter of the PMMA microspheres used is in the range of 30 - 50 μm, and the remaining steps are the same. Thus, the obtained diamond grinding wheel is as Figure 3 shown, and multiple micropores with a pore diameter of 30 - 50 μm are distributed on the diamond grinding wheel body.

[0060] Comparative Example 2 This comparative example provides a ceramic-bonded diamond grinding wheel and its preparation method, which are basically the same as those of the diamond grinding wheel and its preparation method provided in Example 1. The main difference is that: in this comparative example, PMMA microspheres with a pore diameter of 500 μm are used to replace the calcium alginate hydrospheres with the same mass, and phenomena such as black heart (left) or caking and drying cracking (right) as shown in Figure 4 will occur during the process of preparing the diamond micropowder grinding wheel agglomerate.

[0061] The present invention also provides the application of the diamond grinding wheels provided in the above embodiments and Comparative Example 1 as silicon carbide thinning grinding wheels in the processing of silicon carbide wafers. Specifically, the diamond grinding wheels are used to grind 4-inch silicon carbide wafers (roughness 180 nm), silicon wafers (roughness 130 nm), and gallium nitride (roughness 150 nm) on an OKAMOTO grinding machine. The rotational speed of the grinding wheel is 1500 rpm. When the current value is ensured to be 14 A, different feed rates are used for processing for 20 minutes. Then, the processing efficiency is calculated, and the surface roughness of the ground silicon carbide wafers is measured using a SuperViewW1 series white light interferometer. The results are shown in Table 1. Among them, the porosity of the diamond grinding wheels provided in each embodiment and comparative example is shown in Table 1.

[0062] Porosity measurement method: Weigh the weight m of the cut spline. 1 , Place the specimen in a vacuum machine, add distilled water until the specimen is completely covered, start the vacuum extraction machine until the remaining pressure is less than 0.0013 Mpa, and stop pumping when no bubbles appear on the specimen. Then take out the specimen. Place the saturated specimen on the instrument and quickly weigh the weight m of the saturated specimen in air 2 (When using the boiling method, use multiple layers of gauze saturated with water to wipe off the water adhering to the surface of the specimen), accurate to 0.0001 g. Place the saturated specimen in water and weigh its weight m in water 3 , accurate to 0.0001 g. Porosity (%) = (m 3 - m 1 / (m 3 - m 2 ) × 100.

[0063] Table 1 Porosity and processing performance results of diamond grinding wheels Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features; without departing from the scope of this case.

Claims

1. A method for preparing a high-porosity ceramic bond diamond micro-powder grinding tool, comprising the steps of: Preparation of ceramic bond diamond micropowder composite powder: The ceramic bond diamond micropowder composite powder is prepared by a sol-gel method, wherein: The raw materials of the ceramic binder diamond micropowder composite powder include 0-5 wt% of nano filler and diamond micropowder; Preparation of agglomerated diamond microspheres: using the ceramic binder diamond micropowder composite powder and the organic pore-forming agent as raw materials, and adopting an atomization granulation method to prepare porous agglomerated diamond microspheres, wherein the mass ratio of the ceramic binder diamond micropowder composite powder to the organic pore-forming agent is (6-10): (0-4), and the particle size of the organic pore-forming agent is not less than 1.0 μm; Preparation of calcium alginate water ball: using sodium alginate and calcium salt as raw materials, a calcium alginate water ball solution is prepared by adopting multiple emulsion method and atomization granulation method; Preparation of ceramic bond diamond micro-powder grinding tool: using the porous agglomerated diamond microspheres and calcium alginate water balls as main raw materials, the ceramic bond diamond micro-powder grinding tool is prepared by gel injection molding.

2. The preparation method according to claim 1, characterized in that The nanofiller accounts for 0.5-5 wt % and has a particle size of 50-100 nm.

3. The preparation method according to claim 2, characterized in that The raw materials of the ceramic binder diamond micropowder composite powder also include 40-60 wt % of diamond micropowder, and the remainder is the ceramic binder raw material prepared by the sol-gel method.

4. The preparation method according to claim 1, characterized in that The steps of preparing agglomerated diamond microspheres include: firstly mixing the ceramic binder diamond micropowder composite powder and the organic pore-forming agent, and preparing a ceramic mixed slurry according to a solid content of 25-40%; then placing the ceramic mixed slurry in an atomizing granulator for granulation, wherein the atomization frequency is 30-50 Hz and the atomization temperature is 180°C-230°C, to obtain diamond ceramic composite particles; then sintering the diamond ceramic composite particles to obtain the porous agglomerated diamond microspheres.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The organic pore formers include organic pore formers with particle sizes of 1.0-10 μm and 80-500 μm.

6. The preparation method according to any one of claims 1 to 4, characterized in that: The particle size of the organic pore former is 1.0-10 μm.

7. The vitrified bond diamond powder abrasive tool according to claim 6, characterized in that: The mass ratio of the ceramic binder diamond micropowder composite powder to the organic pore-forming agent is (6-8): (2-4), and the particle size of the ceramic binder diamond micropowder composite powder is 0.5-3 μm.

8. The preparation method according to any one of claims 1 to 4 or 7, characterized in that: The step of preparing the calcium alginate water ball comprises: using an atomizing nozzle or a dropper to drop 1-5 wt% sodium alginate solution into 0.5-5 wt% calcium salt solution to prepare the calcium alginate water ball solution.

9. The vitrified bond diamond micro-powder grinding tool according to claim 8, characterized in that: The calcium salt is calcium chloride or calcium lactate.

10. A raw material for a high-porosity ceramic bond diamond micro-powder grinding tool, characterized in that: The porous agglomerated diamond microspheres and calcium alginate water balls are included in a mass ratio of (1-5): (5-15), wherein the particle size of the porous agglomerated diamond microspheres is 5-150 μm, the porous agglomerated diamond microspheres are mainly prepared by using ceramic binder diamond micropowder composite powder and organic pore-forming agent as raw materials, adopting an atomization granulation method, and removing the organic pore-forming agent through muffle furnace sintering, and the raw materials of the ceramic binder diamond micropowder composite powder include 0-5 wt% of nano filler; the particle size of the calcium alginate water ball is 80-600 μm.

11. The raw material according to claim 10, characterized in that The raw materials of the ceramic binder diamond micropowder composite powder include 40-60 wt % of diamond micropowder, and the remainder is the ceramic binder raw material prepared by sol-gel method.

12. The raw material according to claim 10 or 11, characterized in that The raw materials of the calcium alginate water ball include 1-5 wt% sodium alginate solution and 0.5-5 wt% calcium salt solution, wherein the calcium salt is calcium chloride or calcium lactate.

13. A high-porosity ceramic bond diamond micro-powder abrasive tool prepared by the preparation method according to any one of claims 1 to 9, characterized in that: The invention comprises a diamond micro-powder abrasive tool body, large pores closely and evenly distributed in the diamond micro-powder abrasive tool body and small pores distributed between adjacent large pores, wherein the pore diameter of the large pores is 80-1000 μm, and the pore diameter of the small pores is 1.0-10 μm.

14. Use of the high-porosity ceramic bond diamond micro-powder grinding tool according to claim 13 in semiconductor material processing.

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