Diamond grinding wheel and preparation process thereof

Abstract

The application provides a diamond grinding wheel and a preparation process thereof, and belongs to the technical field of abrasive grinding wheels, and aims to solve the technical problems of low strength of the diamond grinding wheel and poor stability in thinning processing of a new generation of semiconductor materials. The preparation process of the diamond grinding wheel comprises the following steps: (1) mixing copper-tin alloy powder, graphene oxide, polyether sulfone resin powder and diamond micro powder, sieving, adding modified alumina hollow spheres, and sieving again to obtain a molding material; and (2) loading the molding material into a mold to perform hot-pressing sintering to form a grinding wheel tooth, and polishing and processing the inner and outer circles of the grinding wheel tooth to obtain the diamond grinding wheel. The modified alumina hollow spheres are alumina hollow spheres coated with a SnS film. The diamond grinding wheel has good sharpness and high strength, can adapt to high-speed and high-feeding processing technology, and has high processing efficiency and surface quality in grinding processing of a new generation of semiconductor materials such as silicon carbide.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of abrasive grinding wheels, and particularly relates to a diamond grinding wheel and a preparation process thereof. BACKGROUND

[0002] In recent years, the technical fields of 5G communication, national defense and military industry, and aerospace have rapidly progressed, and the semiconductor industry has developed substantially. Chip manufacturing is continuously converted to miniaturization, large capacity, and high stability. New generation semiconductor materials such as silicon carbide, gallium nitride, aluminum nitride, gallium oxide, and diamond have higher breakdown voltage, better heat conduction efficiency, and stronger radiation resistance, and are widely used in high-power, high-frequency, and high-temperature occasions. They are the main direction of research and development in the domestic and foreign semiconductor industry.

[0003] New generation semiconductor materials such as silicon carbide have a wide market demand, but compared with silicon, such materials have higher brittleness and hardness, and the processing technical indicators such as roughness, warpage, and flatness are further improved, which greatly increases the difficulty of thinning processing, affecting its development and application. At present, grinding processing of such materials by diamond grinding wheels is the only choice. For example, a Chinese patent application with the publication number CN112497087A discloses a bronze-based diamond grinding wheel with high bending strength and a preparation method thereof. Copper-tin pre-alloy powder is added to the copper-based material, the diamond micro powder is modified and added, the alloying degree of the bronze-based material is effectively improved, boron carbide, chromium oxide, silicon carbide, and other binder components are added, the bonding force between the grinding wheel base material and the binder is greatly enhanced, the strength of the obtained grinding wheel is greatly improved, and the grinding wheel is not easy to break, fall off, or drop off during processing. Although the bronze-based diamond grinding wheel has high bending strength, the binder is not subjected to pore-forming treatment, the self-sharpening property of the obtained grinding wheel is general, the continuous thinning processing capacity of the grinding wheel for materials such as silicon carbide is poor, and the workpiece is easily cracked and scrapped, which cannot meet the high-precision processing requirements of semiconductor materials. In addition, the copper-tin pre-alloy powder needs to be prepared at 800-950℃, the production efficiency is low, and the modification treatment of the diamond micro powder needs to be calcined at 600-700℃, which easily causes oxidation of the diamond and reduces the mechanical properties of the diamond micro powder. In view of the above problems, domestic and foreign researchers add pore-forming agents to the binder to improve the chip removal capacity of the thinning grinding wheel, and then improve the thinning processing efficiency and surface quality. However, the wettability of the pore-forming agent and the binder is generally poor, and the existence of the pores leads to low tooth strength of the grinding wheel. When high-speed thinning processing is adopted, the grinding wheel is easily dropped, which greatly limits the technical improvement of the new generation semiconductor thinning processing. SUMMARY

[0004] In view of the technical problems of low strength of diamond grinding wheel and poor stability in thinning processing of new generation semiconductor materials, the present application provides a diamond grinding wheel and a preparation process thereof, the diamond grinding wheel has good sharpness and high strength, can adapt to high speed and high feed processing technology, and has high processing efficiency and surface quality in grinding processing of new generation semiconductor materials such as silicon carbide.

[0005] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0006] A preparation process of a diamond grinding wheel, comprising the following steps:

[0007] (1) Take copper-tin alloy powder, graphene oxide and polyether sulfone resin powder, mix them uniformly through a three-dimensional mixer, then add diamond micro powder, sieve and add modified alumina hollow spheres, sieve again to obtain molding material;

[0008] (2) Put the obtained molding material into a graphite mold and heat-press form through a hot-press sintering machine, and then naturally cool to obtain grinding wheel teeth;

[0009] (3) Bond the obtained grinding wheel teeth to the end face of an aluminum alloy base, grind the inner and outer circles of the grinding wheel teeth through a vertical grinding machine, and then perform heat solidification enhancement treatment on the outer circle of the grinding wheel teeth through a semiconductor laser after heat treatment, to obtain a diamond grinding wheel with high processing efficiency.

[0010] Specifically, in step (1), the components are as follows in terms of volume fraction: copper-tin alloy powder 10-40 parts, graphene oxide 5-20 parts, polyether sulfone resin powder 5-15 parts, modified alumina hollow spheres 5-40 parts, and diamond micro powder 10-30 parts.

[0011] Further, the copper-tin alloy powder is CuSn45 alloy powder with a particle size of 5-12 μm.

[0012] Further, the particle size of the graphene oxide is 270-325 mesh.

[0013] Further, the particle size of the polyether sulfone resin powder is 20-32 μm, and the particle size of the diamond micro powder is 1000-12000 mesh.

[0014] Specifically, in step (1), take copper-tin alloy powder, graphene oxide and polyether sulfone resin powder according to the formula, mix them uniformly through a three-dimensional mixer, then add diamond micro powder and sieve through a 200 mesh sieve, the ball material mixing ratio of the three-dimensional mixer is 1:3, the rotation speed is 5-20 rpm, and the time is 2-10 h.

[0015] Further, in step (1), the preparation step of the modified alumina hollow sphere is: taking the alumina hollow sphere, placing it in a nitric acid solution for roughening, then washing it to neutral with deionized water, mixing the roughened alumina hollow sphere with stannous chloride dihydrate and urea sulfur uniformly, then placing it in ethylene glycol to configure a reaction solution, stirring at 40-100 DEG C for 1-5h, washing with deionized water after centrifugation, and drying at 60 DEG C to obtain the modified alumina hollow sphere coated with a SnS thin film on the surface.

[0016] Further, the concentration of stannous chloride dihydrate in the reaction solution is 12-15g / L, the concentration of urea sulfur is 17-21g / L, and the alumina hollow sphere is 10g / L, and the particle size of the alumina hollow sphere is 40-80μm; the reaction temperature of the reaction solution is 40-100 DEG C, and the reaction time is 1-5h.

[0017] Further, the modified alumina hollow sphere is added to the mixed powder of copper-tin alloy powder, graphene oxide, polyether sulfone resin powder and diamond micro powder, and then the mixture is sieved through an 80-mesh sieve to obtain a molding material.

[0018] Specifically, in step (2), the sintering temperature for hot-pressing sintering is 340-560 DEG C, the pressure is 2-15MPa, and the holding time is 10-120min.

[0019] Specifically, in step (3), the heat treatment process is: placing the diamond grinding wheel in a resistance box, and immediately performing heat curing and strengthening treatment after holding at 50-90 DEG C for 10-140min. The semiconductor laser power used for heat curing and strengthening treatment is 600-2500W, and the laser wavelength is 915nm.

[0020] The beneficial effects of the present application are:

[0021] (1) The present application introduces modified alumina hollow spheres into the diamond grinding wheel and the idea of heat curing and strengthening the teeth of the grinding wheel. The introduction of modified alumina hollow spheres improves the chip capacity of the diamond grinding wheel during machining, reduces the risk of workpiece burn, and the obtained diamond grinding wheel has high blade height and good machining surface quality during continuous grinding. At the same time, the present application coats SnS thin film on the surface of the alumina hollow sphere to improve the wettability between the alumina hollow sphere and the binder, which can increase the strength of the diamond grinding wheel and improve the wear resistance of the grinding wheel. To further improve the strength of the diamond grinding wheel, the present application performs heat curing and strengthening treatment on the outer circle of the teeth of the grinding wheel by a semiconductor laser. The obtained grinding wheel teeth have high strength and stable grinding performance, and can adapt to high-speed and high-feed machining processes. The grinding efficiency of new-generation semiconductor materials such as silicon carbide is greatly improved.

[0022] (2) The application introduces graphene oxide into the diamond grinding wheel formula to improve the hardness of the grinding wheel and increase the holding force of the binder on the diamond. The polyether sulfone resin powder added in the grinding wheel formula has good creep resistance and size stability at high temperatures. The obtained diamond grinding wheel has the wear resistance of metal binder and the self-sharpening of resin binder, and improves the high-temperature performance of the diamond grinding wheel. It has good sharpness and surface quality when processing hard and brittle materials such as silicon carbide, gallium nitride, aluminum nitride, gallium oxide, diamond and other new generation semiconductor materials.

[0023] (3) The particle size and distribution of unmodified alumina hollow spheres have a certain influence on the performance of the diamond grinding wheel. Alumina hollow spheres with smaller particle size cannot play a good pore-forming role, and the obtained diamond grinding wheel has poor continuous processing capacity for new generation semiconductors such as silicon carbide, and the workpiece surface is easy to burn. Alumina hollow spheres with larger particle size will weaken the strength of the grinding wheel teeth, causing the stability of the diamond grinding wheel to decrease. At the same time, the bonding strength between alumina hollow spheres and the binder is poor, which seriously reduces the mechanical properties of the diamond grinding wheel. The application adopts the sol-gel method to coat SnS film on the surface of alumina hollow spheres. The modified alumina hollow spheres have better dispersibility in the composite binder and good wettability with the binder, and the grinding wheel has high strength. At the same time, the low thermal expansion and high thermal conductivity ultrafine SnO2 ceramic particles generated by the oxidation of SnS film during sintering have good affinity with graphene oxide, which can increase the strength of the diamond grinding wheel and improve the wear resistance and thermal stability of the diamond grinding wheel. In addition, the oxidation of the SnS film on the surface of the modified alumina hollow spheres during sintering can consume the interstitial oxygen of the formed material, which has a deoxidizing effect. The diamond grinding wheel prepared by the application has low production cost and good product stability.

[0024] (4) The heat treatment process of the application can reduce the generation of surface cracks of the grinding wheel teeth after the heat curing and strengthening treatment. The application adjusts the power of the semiconductor laser to improve the laser energy density, so that the binder at the outer circle of the grinding wheel teeth is melted and then solidified again, which can significantly improve the strength. The obtained diamond grinding wheel has low tooth drop rate and high stability, and can adapt to high speed and high feed machining process. The grinding efficiency of new generation semiconductor materials such as silicon carbide is greatly improved. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0026] In the following examples, the raw materials used are all ordinary commercially available products that can be directly purchased or prepared by conventional methods in the art. For example, the polyether sulfone resin powder is purchased from Suzhou Juyuanli Plastic Co., Ltd. with the brand E2020P. The copper-tin alloy powder used is CuSn45 alloy powder purchased from Hebei Yuesuo Wear-resistant Material Co., Ltd.

[0027] Specifically, the particle size of the copper-tin alloy powder is 5-12 μm. The particle size of the graphene oxide is 270 / 325 mesh. The particle size of the polyether sulfone resin powder is 20-32 μm. The particle size of the diamond micro-powder is 8000 mesh.

[0028] Example 1

[0029] A diamond grinding wheel, the preparation process comprising the following steps:

[0030] (1) The alumina hollow spheres are placed in a nitric acid solution for roughening, and then washed with deionized water to neutral. The roughened alumina hollow spheres are mixed uniformly with stannous chloride dihydrate and urea sulfur, and then placed in ethylene glycol, stirred at 80°C for 2 h, washed with deionized water after centrifugation, and dried at 60°C to obtain modified alumina hollow spheres coated with a SnS film. The pH of the nitric acid solution used for roughening is 3, the roughening time is 40 min, the concentration of stannous chloride dihydrate used is 15 g / L, the concentration of urea sulfur is 20 g / L, and the concentration of alumina hollow spheres is 10 g / L. The particle size of the alumina hollow spheres is between 45-60 μm.

[0031] (2) 32 parts of copper-tin alloy powder, 6 parts of graphene oxide, and 8 parts of polyether sulfone resin powder are mixed uniformly by a three-dimensional mixer (the ball-to-material ratio is 1:3, the rotation speed is 15 rpm, and the mixing time is 2 h). After adding 26 parts of diamond micro-powder, the mixture is sieved through a 200 mesh sieve. Then, 28 parts of modified alumina hollow spheres are added to the mixture of copper-tin alloy powder, graphene oxide, polyether sulfone resin powder, and diamond micro-powder, and the mixture is sieved through an 80 mesh sieve to obtain a molding material. The molding material is loaded into a graphite mold and hot-pressed by a hot-pressing sintering machine. After natural cooling, a grinding wheel tooth is obtained. The sintering temperature used for hot-pressing sintering is 480°C, the pressure is 5 MPa, and the holding time is 15 min. The grinding wheel tooth is bonded to the end face of an aluminum alloy substrate. After the inner and outer circles of the grinding wheel tooth are ground by a vertical grinding machine, a high-efficiency diamond grinding wheel is obtained.

[0032] Example 2

[0033] A diamond grinding wheel, the preparation process comprising the following steps:

[0034] (1) Take the alumina hollow sphere to be placed in nitric acid solution and roughened, then washed to neutral by deionized water, mix the roughened alumina hollow sphere with stannous chloride dihydrate and urea sulfur uniformly, then place in ethylene glycol, stir at 80℃ for 2h, wash with deionized water after centrifugation, dry at 100℃, and then the modified alumina hollow sphere coated with SnS film on the surface is obtained, the pH of the nitric acid solution used for roughening is 3, the roughening time is 80min, the stannous chloride dihydrate used is 15g / L, the urea sulfur is 20g / L, and the alumina hollow sphere is 10g / L, and the particle size of the alumina hollow sphere is between 45-60μm.

[0035] (2) Take 38 parts of copper-tin alloy powder, 6 parts of graphene oxide, and 8 parts of polyether sulfone resin powder, mix them uniformly by a three-dimensional mixer (the ball-to-material ratio is 1:3, the rotation speed is 15rpm, and the time is 2h), add 26 parts of diamond powder through a 200-mesh sieve, add 2822 parts of modified alumina hollow spheres to the mixed powder of copper-tin alloy powder, graphene oxide, polyether sulfone resin powder, and diamond powder through an 80-mesh sieve to obtain a molding material. The obtained molding material is loaded into a graphite mold and hot-pressed by a hot-pressing sintering machine, and then naturally cooled to obtain a grinding wheel tooth. The sintering temperature used for hot-pressing sintering is 420℃, the pressure is 5MPa, and the holding time is 15-20min. The obtained grinding wheel tooth is bonded to the end face of an aluminum alloy substrate, and after the inner and outer circles of the grinding wheel tooth are ground by a vertical grinding machine, a high-efficiency diamond grinding wheel is obtained.

[0036] Example 3

[0037] A diamond grinding wheel, the preparation process comprising the following steps:

[0038] (1) Take the alumina hollow sphere to be placed in nitric acid solution and roughened, then washed to neutral by deionized water, mix the roughened alumina hollow sphere with stannous chloride dihydrate and urea sulfur uniformly, then place in ethylene glycol, stir at 80℃ for 2h, wash with deionized water after centrifugation, dry at 100℃, and then the modified alumina hollow sphere coated with SnS film on the surface is obtained, the pH of the nitric acid solution used for roughening is 3, the roughening time is 80min, the stannous chloride dihydrate used is 15g / L, the urea sulfur is 20g / L, and the alumina hollow sphere is 10g / L, and the particle size of the alumina hollow sphere is between 45-60μm.

[0039] (2) Take copper-tin alloy powder 32 parts, graphene oxide 6 parts, polyether sulfone resin powder 8 parts, mix uniformly by three-dimensional mixer (ball material ratio used is 1:3, rotation speed is 15 rpm, time is 2 h), add 26 parts of diamond powder after passing through a 200 mesh sieve. Add modified alumina hollow spheres 28 parts to the mixed powder of copper-tin alloy powder, graphene oxide, polyether sulfone resin powder and diamond powder after passing through an 80 mesh sieve to obtain a molding material. The obtained molding material is loaded into a graphite mold and hot-pressed by a hot-pressing sintering machine, and the sand wheel tooth is obtained after natural cooling. The sintering temperature used for hot-pressing sintering is 480℃, the pressure is 5 MPa, and the holding time is 15 min.

[0040] (3) The obtained sand wheel tooth is bonded to the end face of an aluminum alloy substrate, and the inner and outer circles of the sand wheel tooth are ground by a vertical grinding machine. Then, the diamond grinding wheel is placed in a resistance box and heated at 80℃ for 30 min, and then the outer circle of the sand wheel tooth is immediately treated by a semiconductor laser for thermal solidification and reinforcement. A high machining efficiency diamond grinding wheel is obtained. The power of the semiconductor laser is 1200 W, and the wavelength of the laser is 915 nm.

[0041] Example 4

[0042] A diamond grinding wheel, the preparation process comprising the following steps:

[0043] (1) The alumina hollow spheres are placed in a nitric acid solution for roughening, and then washed with deionized water to neutral. The roughened alumina hollow spheres are mixed uniformly with stannous chloride dihydrate and urea sulfur, and then placed in ethylene glycol and stirred at 80℃ for 2 h. After centrifugation, the product is washed with deionized water and dried at 60℃ to obtain modified alumina hollow spheres coated with SnS thin film. The pH of the nitric acid solution used for roughening is 3, the roughening time is 40 min, the concentration of stannous chloride dihydrate used is 15 g / L, the concentration of urea sulfur is 20 g / L, and the concentration of alumina hollow spheres is 10 g / L. The particle size of the alumina hollow spheres is between 45-60 μm.

[0044] (2) Take copper-tin alloy powder 32 parts, graphene oxide 6 parts, polyether sulfone resin powder 8 parts, mix uniformly by three-dimensional mixer (ball material ratio used is 1:3, rotation speed is 15 rpm, time is 2 h), add 26 parts of diamond powder after passing through a 200 mesh sieve. Add modified alumina hollow spheres 28 parts to the mixed powder of copper-tin alloy powder, graphene oxide, polyether sulfone resin powder and diamond powder after passing through an 80 mesh sieve to obtain a molding material. The obtained molding material is loaded into a graphite mold and hot-pressed by a hot-pressing sintering machine, and the sand wheel tooth is obtained after natural cooling. The sintering temperature used for hot-pressing sintering is 480℃, the pressure is 5 MPa, and the holding time is 15 min.

[0045] (3) The obtained grinding wheel tooth is bonded to the end face of an aluminum alloy base, after the inner and outer circles of the grinding wheel tooth are ground by a vertical grinding machine, the diamond grinding wheel is placed in a resistance box, and after being kept at 80°C for 30 min, the outer circle of the grinding wheel tooth is immediately subjected to heat curing and strengthening treatment by a semiconductor laser, to obtain a high machining efficiency diamond grinding wheel, the power of the semiconductor laser is 1200 W, and the wavelength of the laser is 915 nm.

[0046] Example 5

[0047] A diamond grinding wheel, a preparation process comprising the following steps:

[0048] The alumina hollow spheres are placed in a nitric acid solution for roughening, and then washed to neutral by deionized water. The roughened alumina hollow spheres are mixed with stannous chloride dihydrate and urea sulfur, and then placed in ethylene glycol, stirred at 80°C for 2h, washed with deionized water after centrifugation, and dried at 60°C to obtain modified alumina hollow spheres coated with a SnS film on the surface. The pH of the nitric acid solution used for roughening is 3, the roughening time is 40 min, the stannous chloride dihydrate used is 15 g / L, the urea sulfur is 20 g / L, and the alumina hollow spheres are 10 g / L. The particle size of the alumina hollow spheres is between 45-60 μm.

[0049] Take 32 parts of copper-tin alloy powder, 6 parts of graphene oxide, and 8 parts of polyether sulfone resin powder, mix them evenly by a three-dimensional mixer (the ball-to-material ratio is 1:3, the rotation speed is 15 rpm, and the time is 2h), add 26 parts of diamond powder through a 200 mesh sieve, and add 28 parts of modified alumina hollow spheres to the mixed powder of copper-tin alloy powder, graphene oxide, polyether sulfone resin powder, and diamond powder through an 80 mesh sieve to obtain a molding material. The obtained molding material is loaded into a graphite mold and hot-pressed by a hot-pressing sintering machine, and then naturally cooled to obtain a grinding wheel tooth. The sintering temperature used for hot-pressing sintering is 480°C, the pressure is 5 MPa, and the holding time is 15 min. The obtained grinding wheel tooth is bonded to the end face of an aluminum alloy base, after the inner and outer circles of the grinding wheel tooth are ground by a vertical grinding machine, the diamond grinding wheel is placed in a resistance box, and after being kept at 80°C for 30 min, the outer circle of the grinding wheel tooth is immediately subjected to heat curing and strengthening treatment by a semiconductor laser, to obtain a high machining efficiency diamond grinding wheel, the power of the semiconductor laser is 1500 W, and the wavelength of the laser is 915 nm.

[0050] Comparative Example 1

[0051] Comparative Example 1 is based on Example 5, and the alumina hollow spheres introduced in Comparative Example 1 are not modified.

[0052] comprising the following steps:

[0053] (1) Take copper-tin alloy powder 32 parts, graphene oxide 6 parts, polyether sulfone resin powder 8 parts, mix uniformly by three-dimensional mixer (ball to material ratio used is 1:3, rotation speed is 15 rpm, time is 2 h), add 26 parts of diamond powder after passing through a 200 mesh sieve, add unmodified alumina hollow spheres 28 parts to the mixed powder of copper-tin alloy powder, graphene oxide, polyether sulfone resin powder and diamond powder after passing through an 80 mesh sieve to obtain a molding material. The obtained molding material is loaded into a graphite mold and hot-pressed by a hot-pressing sintering machine, and after natural cooling, a grinding wheel tooth is obtained. The sintering temperature used for hot-pressing sintering is 480℃, the pressure is 5 MPa, and the holding time is 15 min.

[0054] (2) The obtained grinding wheel tooth is bonded to the end face of an aluminum alloy substrate, and after the inner and outer circles of the grinding wheel tooth are ground by a vertical grinding machine, the diamond grinding wheel is placed in a resistance box, and after being kept at 80℃ for 30 min, the outer circle of the grinding wheel tooth is immediately subjected to heat curing and strengthening treatment by a semiconductor laser, to obtain a high machining efficiency diamond grinding wheel. The power of the semiconductor laser is 1500 W, and the wavelength of the laser is 915 nm.

[0055] Comparative Example 2

[0056] Comparative Example 2 is based on Example 5, and in Comparative Example 2, the alumina hollow spheres introduced are not modified, and the grinding wheel tooth is not subjected to heat curing and strengthening treatment by a semiconductor laser. It includes the following steps:

[0057] Take copper-tin alloy powder 32 parts, graphene oxide 6 parts, polyether sulfone resin powder 8 parts, mix uniformly by three-dimensional mixer (ball to material ratio used is 1:3, rotation speed is 15 rpm, time is 2 h), add 26 parts of diamond powder after passing through a 200 mesh sieve, add unmodified alumina hollow spheres 28 parts to the mixed powder of copper-tin alloy powder, graphene oxide, polyether sulfone resin powder and diamond powder after passing through an 80 mesh sieve to obtain a molding material. The obtained molding material is loaded into a graphite mold and hot-pressed by a hot-pressing sintering machine, and after natural cooling, a grinding wheel tooth is obtained. The sintering temperature used for hot-pressing sintering is 480℃, the pressure is 5 MPa, and the holding time is 15 min. The obtained grinding wheel tooth is bonded to the end face of an aluminum alloy substrate, and after the inner and outer circles of the grinding wheel tooth are ground by a vertical grinding machine, a high machining efficiency diamond grinding wheel is obtained.

[0058] Table 1 shows the test results of the grinding wheels in Examples 1-5 and Comparative Examples 1-2 on 6-inch silicon carbide wafers in a DISCO 8640 thinning machine. Each example or comparative example tests 5 grinding wheels, each grinding wheel processes 10 pieces of silicon carbide wafers, the single processing allowance is 25μm, the linear speed of the grinding wheel is 43m / s, and the feed rate is 0.5μm / s.

[0059] Table 1 shows the test results of the grinding wheels in Examples 1-5 and Comparative Examples 1-2 on 6-inch silicon carbide wafers in a DISCO 8640 thinning machine. Each example or comparative example tests 5 grinding wheels, each grinding wheel processes 10 pieces of silicon carbide wafers, the single processing allowance is 25μm, the linear speed of the grinding wheel is 43m / s, and the feed rate is 0.5μm / s.

[0060] Example Ratio of missing teeth Operating current TTV Wear ratio Example 1 6.52％ 10.5A 2 μm 1.22 Example 2 5.84％ 10.4A 2 μm 1.15 Example 3 0.32％ 11.5A 2 μm 0.97 Example 4 0.27％ 10.6A 2 μm 0.92 Example 5 0％ 9.8A 2 μm 0.91 Comparative Example 1 3.12％ 11.7A 2 μm 1.35 Comparative Example 2 15.7％ 12.8A 3 μm 1.37

[0061] From the above table 1, the surface treatment of the alumina hollow sphere and the thermal curing enhancement process of the grinding wheel tooth can significantly improve the strength of the grinding wheel tooth, and the obtained high machining efficiency diamond grinding wheel has small working current, long service life and high workpiece surface quality when machining silicon carbide wafers under high speed and high feed machining process conditions.

[0062] In summary, the modified alumina hollow sphere coated with SnS film is introduced as a pore-forming agent, the modified alumina hollow sphere has good wettability with the binder, the capacity of holding chips of the diamond grinding wheel is increased, the strength of the grinding wheel is improved, the self-sharpening property of the grinding wheel is good, and the wear resistance is high. Meanwhile, the outer circle of the grinding wheel tooth is subjected to thermal curing enhancement treatment by the semiconductor laser, and the obtained diamond grinding wheel can adapt to high speed and high feed machining process, and the grinding machining efficiency of the new generation of semiconductor materials such as silicon carbide is greatly improved.

[0063] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A process for the production of a diamond grinding wheel, characterized in that, It comprises the following steps: (1) mixing copper-tin alloy powder, graphene oxide, polyether sulfone resin powder, diamond micro powder, sieving, adding modified alumina hollow sphere, sieving again to obtain molding material; (2) loading the molding material into a mold for hot-pressing sintering to obtain a grinding wheel tooth, and polishing the inner and outer circles of the grinding wheel tooth to obtain a diamond grinding wheel; The modified alumina hollow sphere is an alumina hollow sphere coated with a SnS film on the surface; In step (1), the components are as follows in volume parts: copper-tin alloy powder 10-40 parts, graphene oxide 5-20 parts, polyether sulfone resin powder 5-15 parts, modified alumina hollow sphere 5-40 parts, and diamond micro powder 10-30 parts; The preparation steps of the modified alumina hollow sphere are as follows: placing alumina hollow spheres in an acidic solution for roughening, mixing the roughened alumina hollow spheres with stannous chloride dihydrate and urea sulfur uniformly, placing them in ethylene glycol to obtain a reaction solution, then performing a reaction, centrifuging, washing, and drying after the reaction to obtain the modified alumina hollow sphere coated with a SnS film on the surface; The diamond grinding wheel obtained in step (2) is subjected to heat treatment, and then the outer circle of the diamond grinding wheel is subjected to heat solidification enhancement treatment by laser.

2. The manufacturing process of a diamond grinding wheel according to claim 1, characterized in that, The copper-tin alloy powder is CuSn45 alloy powder with a particle size of 5-12 μm; the graphene oxide has a particle size of 270-325 mesh; the polyether sulfone resin powder has a particle size of 20-32 μm; and the diamond micro powder has a particle size of 1000-12000 mesh.

3. The process for producing a diamond grinding wheel according to claim 2, characterized in that, The acidic solution in the roughening is nitric acid solution with a pH of 3-4, and the roughening time is 30-150 min.

4. The process for producing a diamond grinding wheel according to claim 3, characterized in that, In the reaction solution, the concentration of stannous chloride dihydrate is 12-15 g / L, the concentration of urea sulfur is 17-21 g / L, the concentration of alumina hollow spheres is 10 g / L, and the particle size of the alumina hollow spheres is 40-80 μm; the reaction temperature of the reaction solution is 40-100 ℃, and the reaction time is 1-5 h.

5. The process for producing a diamond grinding wheel according to claim 4, characterized in that, The sintering temperature for hot-pressing sintering is 340-560 ℃, the pressure is 2-15 MPa, and the holding time is 10-120 min.

6. The process for producing a diamond grinding wheel according to claim 5, wherein The heat treatment temperature is 50-90 ℃, and the time is 10-140 min; the power of the semiconductor laser used for heat solidification enhancement treatment is 600-2500 W, and the wavelength of the laser is 915 nm.

7. The diamond grinding wheel prepared by the process according to any one of claims 1-6.