Silicon carbide boat support and manufacturing method thereof

Abstract

The invention relates to the technical field of silicon carbide boat support manufacturing, and particularly discloses a silicon carbide boat support and a manufacturing method thereof.The manufacturing method comprises the following steps that S1, the boat support is designed through three-dimensional modeling software; s2, uniformly mixing the silicon carbide powder with various particle sizes; s3, slurry preparation: stirring and mixing the powder and a curing agent to obtain slurry; s4, the three-dimensional model slices of the boat support are printed and formed through a 3D printing device, and glue is smeared between every two layers of slices; s5, performing hot air drying on the blank in a drying oven; s6, in a vacuum sintering furnace, the blank is subjected to vacuum sintering and glue discharging; s7, the blank is subjected to polishing, machining, sand blasting, purification, ultrasonic cleaning and drying process treatment; compared with traditional injection molding, the silicon carbide boat support is manufactured through 3D printing, mold production and manufacturing can be omitted, and the production cost is reduced; and various forming parameters are visualized, so that the forming difficulty is reduced, and the yield of the silicon carbide boat support is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing silicon carbide boat trays, and particularly relates to a silicon carbide boat tray and a manufacturing method thereof. Background Art

[0002] A boat tray is a key load-bearing component in the diffusion process equipment of the photovoltaic industry, and its application in the photovoltaic industry is mainly as a carrier for carrying photovoltaic cells.

[0003] In the manufacture of existing silicon carbide boat trays, a blank is usually obtained by injecting silicon carbide slurry into a mold for molding, and then the blank is sintered to obtain the boat tray.

[0004] In the process of injection molding of the blank, on the one hand, the cost of the mold is relatively high; on the other hand, it is also necessary to ensure parameters such as the molding pressure and temperature of the silicon carbide slurry in the mold to ensure that the density and strength of the blank meet the requirements.

[0005] This will result in a relatively high manufacturing cost for injection molding of silicon carbide boat trays, more process requirements for the entire injection molding process, difficulty in ensuring the quality of silicon carbide boat trays, and a relatively low yield rate of silicon carbide boat trays. Summary of the Invention

[0006] In view of the above problems in the prior art, the present invention provides a silicon carbide boat tray and a manufacturing method thereof, aiming to reduce the manufacturing cost of the silicon carbide boat tray and improve the yield rate.

[0007] To achieve the above invention object, the technical solution adopted by the present invention is as follows:

[0008] Provide a manufacturing method of a silicon carbide boat tray, including the following steps: S1. Model design, designing the boat tray through three-dimensional modeling software to obtain a three-dimensional model of the boat tray; S2. Powder ratio, uniformly mixing silicon carbide powders of various particle sizes to obtain powders; S3. Slurry preparation, stirring and mixing the powders and a curing agent to obtain a slurry; S4. Printing and molding, slicing and printing the three-dimensional model of the boat tray through a 3D printing device to obtain a blank, and applying glue between each layer of slices; S5. Pre-sintering treatment, performing hot air drying on the blank in an oven; S6. Sintering and molding, performing vacuum sintering and debinding on the blank in a vacuum sintering furnace; S7. Subjecting the blank to processes such as grinding, machining, sandblasting, purification, ultrasonic cleaning, and drying to obtain a finished silicon carbide boat tray.

[0009] Further, in S3, the mass ratio of the powder to the curing agent is 2000∶1; the slurry is prepared portion by portion, each portion of the slurry includes 20 kg of powder and 0.01 kg of curing agent, and each portion of the slurry needs to be stirred and mixed for 3 minutes.

[0010] Further, in S3, the temperature of the slurry standing environment is 20 - 25°C, the humidity of the slurry standing environment is 40 - 50% RH, and it stands for a fixed duration of 72 h.

[0011] Further, in S3, a carbon source, a composite binder, and a solvent are added to make a slurry, and the silicon carbide powder: composite binder: curing agent: carbon source: solvent are weighed according to a mass ratio of 70:20:2:10:15.

[0012] Further, in S3, premixing: Put the silicon carbide powder and the carbon source into a mixer and mix for 5 h. During the premixing process, heat and raise the temperature of the material to 140°C at a rate of 1°C / min; medium mixing: Add the composite binder and the solvent to the mixer that has undergone premixing, and continue to mix for 6 h at a medium mixing temperature of 130°C, then naturally cool the temperature to 100°C; final mixing: Add the curing agent to the mixer that has undergone medium mixing, and continue to mix for 10 h at a temperature of 100°C, then naturally cool to room temperature to obtain the slurry.

[0013] Further, in S5, the heating rate is 40°C / h, heat up to 180 - 220°C within four hours, and keep warm for 2 h, then take out the blank after natural cooling.

[0014] Further, in S6, perform four - stage heating and sintering on the blank, and the sintering temperatures are 300°C, 800°C, 1450°C, and 1700°C respectively.

[0015] Further, the heating rates for each stage of heating and sintering are respectively: 80°C / h, 80°C / h, 60°C / h, and 50°C / h.

[0016] Further, the holding times required for each stage of heating and sintering are respectively: 2 h, 1 h, 1 h, and 3 h.

[0017] A silicon carbide boat support is also provided, which is made by the above - mentioned manufacturing method of the silicon carbide boat support.

[0018] The beneficial effects of the present invention are as follows: Compared with traditional injection molding, manufacturing a silicon carbide boat support by 3D printing can eliminate the production and manufacturing of molds, reduce production costs, and shorten the manufacturing cycle; there is no need to control various molding parameters in the mold, only the manufacturing of the slurry needs to be controlled, and various molding parameters are visual, reducing the molding difficulty, effectively ensuring the quality of the blank of the silicon carbide boat support, and improving the yield rate of the silicon carbide boat support. Detailed Embodiments

[0019] To better understand the above - mentioned technical solutions, the above - mentioned technical solutions will be described in detail below.

[0020] Example 1

[0021] This embodiment provides a manufacturing method of a silicon carbide boat support, including the following steps: S1. Model design: Design the boat support through 3D modeling software to obtain a 3D model of the boat support; S2. Powder ratio: Uniformly mix silicon carbide powders of various particle sizes to obtain a powder; S3. Slurry preparation: Stir and mix the powder and a curing agent to obtain a slurry; S4. Printing and forming: Slice and print the 3D model of the boat support through a 3D printing device to obtain a blank, and glue is applied between each layer of slices; S5. Pre-sintering treatment: Hot air dry the blank in an oven; S6. Sintering and forming: In a vacuum sintering furnace, perform vacuum sintering and debinding on the blank; S7. Subject the blank to processes such as grinding, machining, sandblasting, purification, ultrasonic cleaning, and drying to obtain a finished silicon carbide boat support.

[0022] Specifically, the 3D modeling software can be 3DSolidWorks and Materialise Magics; in addition, auxiliary supports and product connection parts can be designed on the boat support, and all are chamfered with R2.

[0023] Preferably, in S2, three different particle sizes of silicon carbide powders are selected, and the three particle sizes are 90 - 100 μm, 9 - 10 μm, and 1 - 2.5 μm respectively; the mass ratio of the three different particle sizes of silicon carbide powders is: 45 - 50∶30 - 35∶15 - 20; and the purity is ≥99% and the bulk density is 1.2 - 2.0 g / cm 3 .

[0024] By selecting three different particle sizes of silicon carbide powders for proportioning, the silicon carbide powder has good fluidity, which can ensure uniform spreading and filling during subsequent spraying of the binder, ensure a proper particle size distribution, and improve the density and strength of the blank.

[0025] Specifically, in S3, the mass ratio of the powder to the curing agent is 2000∶1.

[0026] In this embodiment, the curing agent is selected as toluene sulfonic acid; it is worth mentioning that the concentration of toluene sulfonic acid is 0.5%.

[0027] It is worth mentioning that the glue is prepared by proportioning an adhesive, an additive, and a solvent; the adhesive can be selected from one or more of furan resin, polyvinyl alcohol solution, and polyvinylpyrrolidone solution; the additive can be selected from one or more of ammonium polyacrylate, tetramethylammonium hydroxide, herring oil, polyvinyl alcohol, triethyl phosphate, and BYK - 160; the solvent is selected from one or more of absolute ethanol, ethylene glycol, acetone, and deionized water.

[0028] In this embodiment, furan resin is selected as the binder in the glue, and ammonium polyacrylate is selected as the additive; among them, ammonium polyacrylate accounts for 3-8% of the total mass of the glue, and the mass of furan resin accounts for 75-95% of the total mass of the glue.

[0029] Preferably, the slurry is made portion by portion. Each portion of the slurry includes 20 kg of powder and 0.01 kg of curing agent. Each portion of the slurry needs to be stirred and mixed for 3 minutes until the weight of the slurry reaches 20,000 kg to complete the production of the slurry.

[0030] Preferably, in S3, the temperature of the static environment of the slurry is 20-25°C, the humidity of the static environment of the slurry is 40-50%RH, and it is left static for a fixed duration of 72 hours.

[0031] During the printing process, the size of the printer's material box of the 3D printing device needs to be greater than 2500 mm. Using the built-in layout software of the 3D printing device, the three-dimensional model of the boat support is placed in the middle position of the printer's material box. After slicing, it is imported into the 3D printing device to start printing. Among them, slicing is to transform the three-dimensional model into a set of two-dimensional graphics, and each slice corresponds to one layer of the printer. Every time the printer's material spreading mechanism spreads a layer of silicon carbide powder, the printer nozzle will spray a layer of furan resin on the surface of the silicon carbide powder according to the corresponding slice pattern. After completion, the bottom of the material box drops 0.2 mm. This process is repeated until the printing is completed to obtain the blank of the silicon carbide boat support.

[0032] In the present invention, compared with the traditional injection molding, manufacturing the silicon carbide boat support by 3D printing can eliminate the production and manufacturing of molds, reduce the production cost, and shorten the manufacturing cycle; there is no need to control various molding parameters in the mold, and only the manufacturing of the slurry needs to be controlled. Various molding parameters are visualized, reducing the molding difficulty, effectively ensuring the quality of the blank of the silicon carbide boat support, and improving the yield rate of the silicon carbide boat support; the microstructure and properties of the material can be precisely controlled, optimizing the properties such as strength and toughness of the silicon carbide boat support to meet the strict requirements of different application scenarios for material properties. The product is integrally formed, and the strength of the product is superior to that of the assembled product.

[0033] Moreover, manufacturing the silicon carbide boat support by 3D printing will not introduce new impurities, the purity of the boat support is higher, and it also guarantees the conversion efficiency of the subsequent battery chips. In addition, through optimized design and reduction of material waste, the utilization rate of raw materials is close to 100%, which can further save costs, and the processing cycle is also greatly shortened compared with the traditional injection molding process.

[0034] Preferably, in S5, the heating rate is 40°C / h, it is heated to 180-220°C within four hours, and kept warm for 2 hours, and then the blank is taken out after natural cooling.

[0035] Specifically, in the pre-sintering process, after printing is completed, the green body is first left standing for 8 hours and then the excess silicon carbide powder is planed off. Then, the green body is taken out of the printer's material box and the floating powder on the surface is brushed off with a brush. The green body is placed on the platform, and the deformation degree of the platform surface is measured to be less than 0.5 mm. Among them, the deformation degree can be detected by measuring tools and feeler gauges.

[0036] Then it is put into an oven, and the baking temperature is 180 - 220 °C. The oven uses circulating hot air for drying. After heating up to 200 °C within 4 hours, the heating rate is 40 °C, then it is kept warm for 2 hours, and after natural cooling to room temperature, it is taken out of the oven to complete the pre-sintering treatment of the green body.

[0037] Preferably, in S6, the green body is sintered with a four-step heating process, and the sintering temperatures are 300 °C, 800 °C, 1450 °C, and 1700 °C respectively.

[0038] Preferably, the heating rates for each step of the heating sintering are 80 °C / h, 80 °C / h, 60 °C / h, and 50 °C / h respectively.

[0039] Preferably, the holding times required for each step of the heating sintering are 2 hours, 1 hour, 1 hour, and 3 hours respectively.

[0040] Specifically, in a vacuum sintering furnace, the green body is placed on a graphite plate, and silicon particles with a metal impurity content of less than 200 ppm are added at a weight ratio of 1:1. The diameter of the silicon particles is 3 - 5 mm, and the silicon particles are added to the bottom of the green body and are adjacent to the green body. Of course, the vacuum sintering furnace is equipped with a degumming system. Before the heating of the vacuum sintering furnace starts, it is first evacuated to 0 Pa, then heated to 300 °C at a rate of 80 °C / h, then nitrogen is filled to normal pressure and nitrogen is continuously filled at 50 L / min. The degumming valve is opened to start degreasing and remove organic substances. After holding for 2 hours, it is heated to 800 °C at a rate of 60 °C / h. During degreasing, a nitrogen atmosphere is ensured. After holding for 1 hour, the degumming valve is closed; it is continuously evacuated to less than 20 Pa, heated to 1450 °C at a rate of 60 °C / h, held for 1 hour, and then heated to 1700 °C at a rate of 50 °C / h and held for 3 hours. Reaction sintering needs to be carried out in a vacuum environment, and nitrogen is filled and cooled to room temperature with the furnace to complete the sintering and forming work of the green body.

[0041] Through sintering and forming, the density and performance of the green body can be improved, avoiding deformation, cracking or defects of the green body; effectively removing the glue in the green body, preventing problems such as expansion and cracking of the green body during sintering, preventing problems such as grain growth and deformation, and ensuring product quality.

[0042] Of course, the green body that has completed sintering and forming also needs to be processed by grinding, machining, sandblasting, purification, ultrasonic cleaning, and drying processes.

[0043] Among them, for grinding, a 60-mesh diamond grinding disc is used to remove the silicon blocks on the surface of the boat holder; for machining, a gantry milling machine equipped with diamond tools is used to machine the working part of the boat holder, and for sandblasting, 60-mesh silicon carbide sand water jet is used to remove the surface dust and most of the metal residues of the diamond grinding disc.

[0044] It is worth mentioning that purification is to further remove trace metal and oxide impurities such as iron, aluminum, and manganese on the product surface. Dilute hydrochloric acid is used for purification, the concentration of dilute hydrochloric acid is controlled at 10 - 15%, the purification temperature is controlled at 25 - 30 °C, and the purification duration is 30 min; in addition, after purification, the surface of the boat holder is first rinsed with clean water and then placed in an ultrasonic cleaning tank for 30 min; after cleaning and drying, the finished silicon carbide boat holder can be obtained.

[0045] Example 2

[0046] In this example, 10 silicon carbide boat holders are manufactured using the manufacturing method in Example 1, numbered as Example 1, Example 2... Example 10 respectively; 3 silicon carbide boat holders are also manufactured using the traditional injection molding process, numbered as Comparative Example 1, Comparative Example 2, and Comparative Example 3 respectively; and the thermal conductivity, coefficient of thermal expansion, and elastic modulus of the above-mentioned silicon carbide boat holders are all detected, and the detection results are as follows:

[0047]

[0048] By using the manufacturing method provided by the present invention, the experimentally determined silicon carbide boat holder obtained has: SiC% ≥ 80%, free silicon ≤ 20%, elastic modulus ≥ 350 GPa, thermal conductivity (1000 °C) > 50 W / mK, coefficient of thermal expansion (1000 °C) less than 3.0×10 -6 / °C, apparent porosity ≤ 0.01%, bulk density ≥ 2.85 g / cm 3 ; the Fe content in the internal fracture of the finished silicon carbide boat holder is measured to be ≤ 100 ppm, and the Al content is ≤ 100 ppm; the overall Fe content of the silicon carbide boat holder is < 400 ppm, the Al content is < 400 ppm, and the total content of other metal impurities is < 200 ppm.

[0049] It can be seen that the physical properties of the silicon carbide boat holder provided by the present invention can be significantly improved. The elastic modulus ≥ 350 GPa, with stronger resistance to deformation, good load-bearing capacity, excellent stability and durability; at a temperature of 1000 °C, the thermal conductivity > 50 W / mK, which can quickly conduct heat, reduce the production cycle of the process and reduce the energy consumption during the production process; at a temperature of 1000 °C, the coefficient of thermal expansion is less than 3.0×10 -6 / ℃, it is not easy to deform during the reaction, and in subsequent manufacturing, the production qualification rate of the battery chips; moreover, the silicon carbide boat support has a low impurity content and can meet the requirements of the silicon wafer diffusion process in the photovoltaic and semiconductor industries for service life and pollution-free.

[0050] Specifically, in the above tests, the flexural strength adopts GB / T 19651996 "Test Method for Flexural Strength of Porous Ceramics"; the thermal conductivity adopts GB / T 225882008 "Method for Measuring Thermal Diffusion Coefficient or Thermal Conductivity by Flash Method"; the coefficient of thermal expansion adopts GB / T 165352008 "Test Method for Linear Thermal Expansion Coefficient of Fine Ceramics Push Rod Method".

[0051] Example 3

[0052] Preferably, in S2, the particle morphology of the silicon carbide powder is spherical or ellipsoidal, the sphericity of the silicon carbide powder is ≥ 0.92, and the particle size of the silicon carbide powder is 80 - 200 um.

[0053] In this embodiment, according to the diameter of the silicon carbide powder, it is divided into three particle sizes

[0054] Specifically, in S3, a carbon source, a composite binder and a solvent are added to make a slurry, and various raw materials are weighed according to the mass ratio of silicon carbide powder: composite binder: curing agent: carbon source: solvent of 70:20:2:10:15.

[0055] In this embodiment, the composite binder is composed of epoxy resin, phenolic resin and phenolic epoxy resin mixed according to the mass ratio of 1:1:1; the curing agent is composed of phthalic acid and diethylenetriamine mixed according to the mass ratio of 1:1; among them, the carbon source is selected as graphite and the solvent is selected as ethanol.

[0056] Preferably, the preparation of the slurry undergoes three mixings: premixing, intermediate mixing and final mixing.

[0057] Among them, premixing: Put the silicon carbide powder and the carbon source into a mixer and mix for 5 h. During the premixing process, heat the material at a rate of 1 °C / min to 140 °C.

[0058] Intermediate mixing: Add the composite binder and the solvent to the mixer that has undergone premixing, and continue to mix for 6 h at the intermediate mixing temperature of 130 °C, and then the temperature naturally drops to 100 °C.

[0059] Final mixing: Add the curing agent to the mixer that has undergone intermediate mixing, and continue to mix for 10 h at a temperature of 100 °C, and then naturally drop to room temperature to obtain the slurry.

[0060] Preferably, in this embodiment, by drying and crushing or spray granulating the slurry, silicon carbide composite powder for printing and forming can be obtained, and the working temperature adopted for spray granulation is 90 °C.

[0061] In this embodiment, the main technological processes of premixing, intermediate mixing, final mixing and granulation are adopted. This method can select the corresponding mixing temperature and mixing time according to the characteristics of different raw materials; premixing can make silicon carbide powders of different sizes and carbon sources be fully and evenly mixed; intermediate mixing can enable the composite binder to wrap the evenly mixed silicon carbide powders and carbon sources together to form a pseudo-aggregate; final mixing introduces a curing agent at a lower temperature and makes the curing agent be fully and evenly mixed with the pseudo-aggregate; granulation can optimize and improve the morphology of the mixed powder. After granulation, powders with inconsistent particle size dimensions are obtained, and the mixing of powders with multi-particle size distributions is beneficial to improving the packing density of the powder and the fluidity of the powder, so as to improve the density of the subsequent 3D printed silicon carbide composite green body.

[0062] By using the silicon carbide composite powder provided in this embodiment, the green body obtained by 3D printing has a high density, high green body strength and high green body stability; during the subsequent sintering process, the shrinkage is small, the high-temperature deformation is small, the density of the sintered silicon carbide composite material is high, the mechanical properties are strong, and the overall performance is excellent, having great application prospects.

[0063] Particularly, for large-size and large-weight silicon carbide products, using the preparation method provided in this embodiment can not only make different raw materials be fully and evenly mixed, but also prevent the composite binder and the curing agent from being invalidated due to premature reaction. It is a high-quality and efficient preparation method, suitable for large-scale production, and has broad development prospects.

[0064] Preferably, during the 3D printing process, the ambient temperature is 20 - 30 °C, and the ambient humidity is controlled at 40 - 60% rh.

[0065] Preferably, during the 3D printing process, the cartridge pressure controls the main negative pressure of the binder injection at 3.0 - 3.1 mbar, the circulating negative pressure at 4.0 - 4.1 mbar, the distance between the nozzle and the sand surface: 3 - 5 mm; the printing speed in the X direction is 0.54 m / s, and the printing speed in the Y direction is 0.8 m / s.

[0066] It is worth mentioning that traditional printers mainly print ordinary sand, the main component of which is silicon dioxide. The silicon carbide material we use is completely different from silicon dioxide in terms of hardness and fluidity; preferably, in this embodiment, the track adopted by the 3D printer is chromium-plated stainless steel. For the uniformity of the sand surface, the vibration frequency of sand spreading is 3950 revolutions per minute. At such a frequency, the integrity of the sand surface and the density of the final product can be optimized, and it can reach 2.0 g / cm 3 After completing one layer of sand spreading, then a pattern is printed once. After completing one cycle, the bottom of the material box drops 0.2 mm, and so on until the printing is completed.

[0067] Each time the printer's material laying mechanism lays a layer of silicon carbide powder, we need to control the temperature and humidity of the printing environment. The temperature is controlled at 20-30℃, and the humidity is controlled at 40-60%. The print head selects Fuji Starlight nozzle for adhesive injection. The injection switch is a piezoelectric ceramic piece that controls the deformation through voltage to accurately control the ink injection amount. In order to ensure better adhesion of the sand surface, it is also necessary to ensure that the injection pressure is not too large, resulting in the loss of the sand surface. When staying, the resin will not drip in the non-effective area or too much ink will be dripped. The speed of the print head and the distance between the print head and the sand surface also need to be precisely controlled. After repeated tests, the current optimal ink cartridge pressure control is that the main negative pressure of the adhesive injection is controlled at 3.0-3.1mbar, the circulating negative pressure is 4.0-4.1mbar, the nozzle is 3-5mm away from the sand surface, and the printing speed in the X direction is 0.54m / s , Y direction 0.8m / s. Under this pressure, the printer nozzle will spray a layer of furan resin on the surface of silicon carbide powder according to the slice pattern. Traditional printers mainly print ordinary sand, the main component of which is silicon dioxide. Compared with silicon dioxide, the silicon carbide material we use is completely different in hardness and fluidity. The equipment loading and sand-laying structural parts used have been optimized. The tracks used are stainless steel with a special chrome plating process. In order to ensure the uniformity of the sand surface, our sander has been specially modified. The vibration frequency of the sanding is currently verified to be 3950 rpm. At this frequency, the integrity of the sand surface and the final product density are optimal, which can be 2.0g / cm3. After completing a layer of sanding, a pattern is printed. After completing a cycle, the bottom of the material box drops by 0.2mm, and so on until the printing is completed.

[0068] It should be understood by those skilled in the art that, although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments once those skilled in the art are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and the equivalent technology, the present invention is also intended to include these modifications and variations.

Claims

1. A method for manufacturing a silicon carbide boat support, characterized in that: The following steps are involved: S1. Model design: design the boat support through 3D modeling software to obtain a 3D model of the boat support; S2. Powder ratio, mixing silicon carbide powders of various particle sizes evenly to obtain powder; S3. Slurry preparation, mixing the powder and the curing agent to obtain a slurry; S4. Printing and forming, using a 3D printing device to slice and print the three-dimensional model of the boat support to obtain a blank, and glue is applied between each layer of slices; S5. Pre-burning treatment, hot air drying the blank in an oven; S6. Sintering and forming, in a vacuum sintering furnace, vacuum sintering the blank and removing the glue; S7. The blank is subjected to grinding, machining, sandblasting, purification, ultrasonic cleaning and drying processes to obtain a finished silicon carbide boat support.

2. The method for manufacturing a silicon carbide boat support according to claim 1, characterized in that: In S3, the mass ratio of powder to curing agent is 2000:1; the slurry is prepared in portions, each portion of slurry includes 20 kg of powder and 0.01 kg of curing agent, and each portion of slurry needs to be stirred and mixed for 3 minutes.

3. The method for manufacturing a silicon carbide boat support according to claim 2, characterized in that: In S3, the temperature of the slurry static environment is 20-25°C, the humidity of the slurry static environment is 40-50%RH, and the static fixed time is 72h.

4. The method for manufacturing a silicon carbide boat support according to claim 1, characterized in that: In S3, a carbon source, a composite binder and a solvent are added to prepare a slurry, and the silicon carbide powder: composite binder: curing agent: carbon source: solvent are weighed according to a mass ratio of 70:20:2:10:

15.

5. The method for manufacturing a silicon carbide boat support according to claim 4, characterized in that: In S3, premixing: put silicon carbide powder and carbon source into a mixer and mix for 5 hours. During the premixing process, heat the materials to 140°C at a rate of 1°C / min; intermediate mixing: add composite binder and solvent to the mixer after premixing, and continue mixing at an intermediate mixing temperature of 130°C for 6 hours, and then naturally reduce the temperature to 100°C; final mixing: add curing agent to the mixer after intermediate mixing, and continue mixing at 100°C for 10 hours, and then naturally reduce to room temperature to obtain slurry.

6. The method for manufacturing a silicon carbide boat support according to claim 1, characterized in that: In S5, the heating rate is 40°C / h, the temperature is raised to 180-220°C within four hours, and kept at this temperature for 2 hours, and the blank is taken out after natural cooling.

7. The method for manufacturing a silicon carbide boat support according to claim 1, characterized in that: In S6, the blank is subjected to four-step temperature-raising sintering, and the sintering temperatures are 300°C, 800°C, 1450°C and 1700°C respectively.

8. The method for manufacturing a silicon carbide boat support according to claim 7, characterized in that: The heating rates of each stage of sintering are 80°C / h, 80°C / h, 60°C / h and 50°C / h respectively.

9. The method for manufacturing a silicon carbide boat support according to claim 7, characterized in that: The holding time required for each stage of temperature increase sintering is 2h, 1h, 1h and 3h respectively.

10. A silicon carbide boat support, characterized in that: The silicon carbide boat support is manufactured by the manufacturing method of any one of claims 1 to 9.

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