Preparation method and application of boron nitride isolation layer

Abstract

The invention relates to the technical field of ceramic materials, in particular to a preparation method and application of a boron nitride isolation layer. The method comprises the following steps: dispersing boron nitride nanotubes and boron nitride rodlike fiber crystals in a solvent, adding a binder, uniformly mixing, pouring onto a porous high-silicon-boron glass template, uniformly blade-coating the surface, and drying to obtain the boron nitride isolation layer with a rodlike array structure. The boron nitride isolation layer is of a rod-shaped array structure and is applied to the ceramic biscuit degreasing process, ceramic green bodies are flatly stacked in the degreasing process, the degreasing rate can be increased, and the problem that an isolation piece adheres to the surface of a ceramic biscuit piece after degreasing is completed can be solved. The ceramic biscuit prepared by the method disclosed by the invention is high in strength and high in uniformity.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic materials, and particularly relates to a preparation method and application of a boron nitride isolation layer. Background Art

[0002] Ceramic substrates are gradually becoming one of the hottest research fields. The degreasing process is indispensable in the preparation process of ceramic substrates. In order to prevent the ceramic green bodies from sticking during the degreasing process, generally an isolation layer is used to separate the green bodies from each other. The commonly used isolation method is to sprinkle or spray boron nitride powder on the surface of the ceramic green body. However, it is very difficult to coat the boron nitride powder completely and evenly on the surface of the green body by these two methods. There will more or less be places with uneven thickness, protrusions or depressions, and such protrusions or depressions will cause the ceramic green body to bend and deform, seriously affecting the yield rate during the preparation process of the ceramic substrate.

[0003] In addition, degreasing under different atmospheres has different effects. For degreasing in an oxidizing atmosphere, the organic additive components in the green body will simultaneously undergo thermal degradation and oxidative degradation, generating a large amount of cracking products. Especially when the pore channels have not been formed in the green body, the escape of the cracking products cannot be discharged in time and effectively, and a strong pressure is formed in the green body, causing the green body to crack and delaminate. Degreasing in a nitrogen atmosphere only has thermal degradation and no oxidation reaction, effectively inhibiting the instantaneous large-scale decomposition of polymers. If pressure-assisted degreasing is adopted, when the internal and external pressures of the green body are balanced and the external pressure increases, the volume of the gas formed by the decomposition in the green body is greatly reduced, so that the cracking caused by the expansion of the gas volume in the green body can be overcome. When degreasing in nitrogen, since the chain decomposition of polymers is a random process and its cracking rate is related to the activation energy, the cracking products mainly depend on the temperature and the heating rate. Most of the existing technologies use a constant heating rate.

[0004] In summary, the strength, uniformity, etc. of the existing ceramic green bodies still need to be further improved. Summary of the Invention

[0005] Aiming at the above problems, the main purpose of the present invention is to provide a preparation method and application of a boron nitride isolation layer. The boron nitride isolation layer described in the present invention has a rod-like array structure and is applied in the degreasing process of ceramic green bodies, enabling the ceramic green bodies to be stacked flat during the degreasing process, which can not only improve the degreasing rate but also solve the problem that the isolation sheet adheres to the surface of the ceramic green body sheet after degreasing is completed.

[0006] Another main purpose of the present invention is to provide a preparation method of a ceramic green body. By using the method described in the present invention, a ceramic green body with high strength and high uniformity can be prepared.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for preparing a boron nitride isolation layer. The method includes the following steps: Dispersing boron nitride nanotubes and boron nitride rod-shaped fiber crystals in a solvent, adding a binder and mixing evenly, then pouring the mixture onto a porous high-silica borate glass template, scraping the surface evenly, and drying to obtain a boron nitride isolation layer with a rod-shaped array structure.

[0009] The staggered stacking of boron nitride nanotubes and boron nitride rod-shaped fiber crystals, combined with the pores of the boron nitride nanotubes themselves, can be used to prepare a porous boron nitride isolation sheet, improving the defatting rate.

[0010] Further, the diameter of the boron nitride nanotubes is 10 - 30 nm, the length is 1 - 10 μm, the diameter of the boron nitride rod-shaped fiber crystals is 1 - 5 μm, and the length is 50 - 300 μm.

[0011] Further, the solvent is ethanol; the binder is polyvinylpyrrolidone. After PVP decomposes at a higher temperature, it will form a film to reinforce the structure of the boron nitride sheet and improve the stability.

[0012] Further, the thickness of the porous high-silica borate glass template is 1 - 10 mm, the surface pore density is 50 - 100 pores / cm 2 , the pore diameter is 10 - 50 μm, and the pore depth is 10 - 100 μm.

[0013] Further, the scraping thickness of the surface is 25 - 100 μm.

[0014] Further, drying is carried out under the condition of 65 - 70 °C.

[0015] The present invention also provides the application of the boron nitride isolation layer prepared by the above method in the defatting of ceramic green bodies.

[0016] The present invention provides a method for preparing a ceramic green body. The method includes the following steps: After the boron nitride isolation layer prepared by the method and the ceramic green body are stacked at intervals, they are clamped with a backing plate and a cover plate for defatting, wherein the side of the boron nitride isolation layer with a rod-shaped array structure is in contact with the upper surface of the ceramic green body.

[0017] Boron nitride nanotubes generally belong to a hollow and porous structure. After being mixed with a binder, the nanotubes still maintain their hollow and porous structure, while boron nitride rod-like fibers are equivalent to the struts connecting the nanotubes. Due to the interlaced and interpenetrating characteristics of the nanotubes and nanofibers, a stable support structure can be maintained even after the binder is removed at high temperature. After the boron nitride binder volatilizes, the porous structure of the boron nitride rod-like fibers and nanotubes forms a degreasing "flue", providing a path for the volatilization of the binder, which can effectively accelerate the degreasing process and make the degreasing more uniform. In addition, a boron nitride isolation layer with a macroscopic array rod structure formed by boron nitride nanotubes and fibrous crystals through a template method. Since there are gaps between the array rods and they can provide a supporting effect, more gaps are provided for the volatilization of the binder during the degreasing of the silicon nitride green body, enabling the polymer binder to be fully degraded and uniformly volatilized, effectively improving the degreasing rate, avoiding the phenomenon of boron nitride powder adhering to the surface of the silicon nitride green body, and solving the problems of unevenness caused by traditional direct spreading of boron nitride isolation powder, damage to the surface of the green body during spraying with a spray gun, damage to the green body by the solvent, and the boron nitride isolation powder being directly embedded in the surface of the green body due to the action of the spray gun, thus affecting problems such as low strength and large warpage of the green body after degreasing.

[0018] Further, the steps of degreasing include the following: Under a nitrogen atmosphere, the temperature is raised to 200 - 230 °C at a rate of 0.5 - 2.5 °C / min, then the temperature is raised to 400 - 430 °C at a rate of 0.1 - 1.0 °C / min, and then the temperature is raised to 630 - 650 °C at a rate of 1.5 - 2.5 °C / min, and kept at 630 - 650 °C for 1 - 2 h; the nitrogen is exhausted, air is introduced, and it is kept at 630 - 650 °C under an air atmosphere for 3 - 4 h, and then cooled to room temperature.

[0019] Further, the air delivery air flow rate is not higher than 4 - 6 m / s.

[0020] Degreasing in a nitrogen atmosphere only undergoes a thermal degradation reaction with a small reaction amount, and the degreasing is slow and uniform; when the temperature reaches the highest, replacing nitrogen with air can enable the remaining organic matter to fully react, making the degreasing efficiency reach the best, which is beneficial to the performance stability of the substrate after subsequent sintering.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention provides a method for preparing a boron nitride isolation layer that is uniform, porous and has a rod-like array structure. This isolation layer can stack ceramic substrates flatly, improve the deformation of the ceramic green body caused by the protrusion of the isolation sheet. At the same time, the porous structure of the isolation layer can improve the degreasing rate, and the special rod-like array structure can also solve the problem of the isolation sheet adhering to the surface of the ceramic green body after degreasing is completed.

[0023] The present invention also provides a method for preparing a silicon nitride ceramic green body. During the debinding process of the method, the organic components are first subjected to thermal degradation reaction in a nitrogen atmosphere, and then air is introduced to fully degrade the remaining organic substances through oxidation reaction and thermal reaction. This method can not only improve the problems such as cracking, swelling, and breaking caused by the traditional debinding process, but also make the organic substances in the green body react sufficiently, which is beneficial to improving the performance of the subsequent sintered product. The ceramic green body prepared by the method of the present invention has high strength and high uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of the boron nitride isolation layer and the high borosilicate glass plate according to the embodiment of the present invention;

[0025] Figure 2 It is a schematic structural diagram of the boron nitride isolation layer and the ceramic green body being adhered according to the present invention;

[0026] Figure 3 It is a sample diagram of the silicon nitride ceramic green body after debinding according to the present invention.

[0027] Illustration: 1 is a boron nitride isolation layer with a rod array structure, 2 is a porous high-silicon boron glass template, 3 is a ceramic green body, 4 is a cover plate, 5 is a backing plate, and 6 is a frame. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, and / or combinations thereof.

[0030] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0031] Embodiment 1

[0032] A method for preparing a boron nitride isolation layer:

[0033] (a) Prepare boron nitride nanotubes with a length of 3 μm and a diameter of 10 nm, and boron nitride rod-shaped fiber crystals with a length of 150 μm and a diameter of 3 μm;

[0034] (b) Disperse the boron nitride nanotubes and boron nitride rod-like fibers in ethanol, add polyvinylpyrrolidone and mix evenly to form a slurry.

[0035] (c) Pour the slurry onto a porous high-silica borosilicate glass template, scrape and coat it evenly, and the coating thickness is 80 μm; the porous high-silica borosilicate glass template has a length and width of 138 * 190 mm, a thickness of 1 mm, a surface pore density of 100 pores / cm 2 , a pore diameter of 20 μm, and a pore depth of 50 μm.

[0036] (d) Take it out after drying in an oven at 70 °C and set aside.

[0037] A method for debinding a ceramic green body includes the following steps:

[0038] (1) Prepare a silicon nitride ceramic green body product with a size of 138 * 190 mm.

[0039] (2) After stacking the prepared boron nitride isolation layer and the silicon nitride ceramic green body at intervals, clamp them with a boron nitride backing plate and a cover plate.

[0040] (3) Put the whole into a debinding furnace for debinding: Under a nitrogen atmosphere, heat from room temperature (25 °C) to 200 °C at a rate of 1.46 °C / min; then heat to 400 °C at a rate of 0.56 °C / min, and then heat to 630 °C at a rate of 1.28 °C / min and hold for 1 hour; discharge the nitrogen and introduce air, the air conveying gas flow rate is 4 m / s, and hold for 3 hours under an air atmosphere at 630 °C; cool naturally to room temperature. After the temperature of the debinding furnace drops to room temperature, take it out, measure the flexural strength and warpage and record the data.

[0041] Example 2

[0042] A method for preparing a boron nitride isolation layer:

[0043] (a) Prepare boron nitride nanotubes with a length of 5 μm and a diameter of 10 nm, and boron nitride rod-like fibers with a length of 100 μm and a diameter of 2 μm.

[0044] (b) Disperse the boron nitride nanotubes and boron nitride rod-like fibers in ethanol, add polyvinylpyrrolidone and mix evenly to form a slurry.

[0045] (c) Pour the slurry onto a porous high-silica borosilicate glass template, scrape and coat it evenly, and the coating thickness is 80 μm; the porous high-silica borosilicate glass template has a length and width of 138 * 190 mm, a thickness of 1 mm, a surface pore density of 100 pores / cm 2 , a pore diameter of 20 μm, and a pore depth of 50 μm.

[0046] (d) Remove it after drying in an oven at 70 °C for standby.

[0047] A method for debinding a ceramic green body, comprising the following steps:

[0048] (1) Prepare a silicon nitride ceramic green body product with dimensions of 138 * 190 mm;

[0049] (2) After stacking the prepared boron nitride isolation layer and the silicon nitride ceramic green body at intervals, clamp them with a boron nitride backing plate and a cover plate;

[0050] (3) Put the whole into a debinding furnace for debinding: Under a nitrogen atmosphere, heat from room temperature (25 °C) to 230 °C at a rate of 1.71 °C / min; then heat to 400 °C at a rate of 0.35 °C / min, and then heat to 630 °C at a rate of 1.92 °C / min, and hold for 1 hour; discharge the nitrogen and introduce air, with the air delivery gas flow rate being 4 m / s, and hold for 3 hours under an air atmosphere at 630 °C; cool naturally to room temperature. After the temperature of the debinding furnace drops to room temperature, take it out, measure the flexural strength and warpage degree and record the data.

[0051] Example 3

[0052] A method for preparing a boron nitride isolation layer:

[0053] (a) Prepare boron nitride nanotubes with a length of 7 μm and a diameter of 30 nm, and boron nitride rod-like fibers with a length of 200 μm and a diameter of 4 μm;

[0054] (b) Disperse the boron nitride nanotubes and boron nitride rod-like fibers in ethanol, add polyvinylpyrrolidone and mix evenly to form a slurry;

[0055] (c) Pour the slurry onto a porous high-silica borosilicate glass template, scrape it evenly, and the coating thickness is 80 μm; the porous high-silica borosilicate glass template has a length and width of 138 * 190 mm, a thickness of 1 mm, a surface pore density of 100 pores / cm 2 , a pore diameter of 20 μm, and a pore depth of 50 μm.

[0056] (d) Remove it after drying in an oven at 70 °C for standby.

[0057] A method for debinding a ceramic green body, comprising the following steps:

[0058] (1) Prepare a silicon nitride ceramic green body product with dimensions of 138 * 190 mm;

[0059] (2) After stacking the prepared boron nitride isolation layer and the silicon nitride ceramic green body at intervals, clamp them with a boron nitride backing plate and a cover plate;

[0060] (3) Place the whole into a degreasing furnace for degreasing: Under a nitrogen atmosphere, heat from room temperature (25°C) to 230°C at a rate of 1.71°C / min; then heat to 400°C at a rate of 0.35°C / min, and then heat to 650°C at a rate of 2.08°C / min, and hold for 1 hour; discharge the nitrogen, introduce air, the air delivery air flow rate is 4 m / s, and hold for 3 hours under an air atmosphere at 630°C; cool naturally to room temperature. After the temperature of the degreasing furnace reaches room temperature, take it out, measure the flexural strength and warpage and record the data.

[0061] Example 4

[0062] A preparation method of a boron nitride isolation layer:

[0063] (a) Prepare boron nitride nanotubes with a length of 5 μm and a diameter of 30 nm and boron nitride rod-shaped fiber crystals with a length of 200 μm and a diameter of 3 μm;

[0064] (b) Disperse the boron nitride nanotubes and boron nitride rod-shaped fiber crystals in ethanol, add polyvinylpyrrolidone and mix evenly to form a slurry;

[0065] (c) Pour the slurry onto a porous high-silica boron glass template, scrape it evenly, and the coating thickness is 80 μm; the porous high-silica boron glass template is 138*190 mm in length and width, 1 mm in thickness, the surface pore density is 100 pores / cm 2 , the pore diameter is 20 μm, and the pore depth is 50 μm.

[0066] (d) After drying in an oven at 70°C, take it off and set it aside.

[0067] A method for degreasing a ceramic green body, comprising the following steps:

[0068] (1) Prepare a silicon nitride ceramic green body product of 138*190 mm;

[0069] (2) After stacking the prepared boron nitride isolation layer and the silicon nitride ceramic green body at intervals, clamp them with boron nitride backing plates and cover plates;

[0070] (3) Place the whole into a degreasing furnace for degreasing: Under a nitrogen atmosphere, heat from room temperature (25°C) to 230°C at a rate of 1.71°C / min; then heat to 400°C at a rate of 0.35°C / min, and then heat to 650°C at a rate of 2.08°C / min, and hold for 2 hours; discharge the nitrogen, introduce air, the air delivery air flow rate is 4 m / s, and hold for 3 hours under an air atmosphere at 630°C; cool naturally to room temperature. After the temperature of the degreasing furnace reaches room temperature, take it out, measure the flexural strength and warpage and record the data.

[0071] Example 5

[0072] A preparation method of a boron nitride isolation layer:

[0073] (a) Prepare boron nitride nanotubes with a length of 5 μm and a diameter of 10 nm, and boron nitride rod-like fibrous crystals with a length of 200 μm and a diameter of 2 μm;

[0074] (b) Disperse the boron nitride nanotubes and boron nitride rod-like fibrous crystals in ethanol, and add polyvinylpyrrolidone and mix evenly to form a slurry;

[0075] (c) Pour the slurry onto a porous high-silica borosilicate glass template, scrape it evenly, and the coating thickness is 80 μm; the porous high-silica borosilicate glass template has a length and width of 138 * 190 mm, a thickness of 1 mm, a surface pore density of 100 pores / cm 2 , a pore diameter of 20 μm, and a pore depth of 50 μm.

[0076] (d) After drying in an oven at 70 °C, remove it and set it aside for later use.

[0077] A method for debinding a ceramic green body, comprising the following steps:

[0078] (1) Prepare a silicon nitride ceramic green body product with dimensions of 138 * 190 mm;

[0079] (2) After stacking the prepared boron nitride isolation layer and the silicon nitride ceramic green body at intervals, clamp them with boron nitride backing plates and cover plates;

[0080] (3) Put the whole into a debinding furnace for debinding: Under a nitrogen atmosphere, heat from room temperature (25 °C) to 230 °C at a rate of 1.71 °C / min; then heat to 400 °C at a rate of 0.35 °C / min, and then heat to 650 °C at a rate of 2.08 °C / min, and hold for 2 hours; discharge the nitrogen and introduce air, the air conveying gas flow rate is 4 m / s, and hold for 4 hours under an air atmosphere at 630 °C; cool naturally to room temperature. After the temperature of the debinding furnace drops to room temperature, take it out, measure the flexural strength and warpage and record the data.

[0081] Comparative Example 1

[0082] (a) First, heat and mix polyvinylpyrrolidone and ethanol, and after complete dissolution, add boron nitride and a dispersant and disperse them evenly.

[0083] (b) Introduce the dispersed slurry into a spray gun and spray boron nitride on the surface of a silicon nitride ceramic green body with dimensions of 138 * 190 mm.

[0084] (c) After stacking the green bodies with boron nitride isolation layers at intervals, clamp them with boron nitride backing plates and cover plates;

[0085] (d) Put the whole into a degreasing furnace for degreasing: Under a nitrogen atmosphere, heat from room temperature (25°C) to 230°C at a rate of 1.71°C / min; then heat to 400°C at a rate of 0.35°C / min, and then heat to 630°C at a rate of 1.92°C / min, and hold for 1 hour; discharge the nitrogen, introduce air, and the air conveying air flow rate is 4 m / s, and hold for 3 hours under an air atmosphere at 630°C; cool naturally to room temperature.

[0086] (e) Take it out after the temperature of the degreasing furnace has cooled to room temperature, measure the flexural strength and warpage and record the data.

[0087] Comparative Example 2

[0088] (a) First, take a certain amount of boron nitride powder, and then place the powder on a 200-mesh wire mesh plate for spreading.

[0089] (b) Prepare a silicon nitride ceramic green body of 138*190 mm, and directly screen the boron nitride powder on the surface of the wire mesh plate onto the surface of the green body through the wire mesh.

[0090] (c) After stacking the green bodies with boron nitride isolation layers, clamp them with boron nitride backing plates and cover plates;

[0091] (d) Put the whole into a degreasing furnace for degreasing according to the set process: Under a nitrogen atmosphere, heat from room temperature (25°C) to 230°C at a rate of 1.71°C / min; then heat to 400°C at a rate of 0.35°C / min, and then heat to 630°C at a rate of 1.92°C / min, and hold for 1 hour; discharge the nitrogen, introduce air, and the air conveying air flow rate is 4 m / s, and hold for 3 hours under an air atmosphere at 630°C; cool naturally to room temperature.

[0092] (e) Take it out after the temperature of the degreasing furnace has cooled to room temperature, measure the flexural strength and warpage and record the data.

[0093] To better illustrate the advantages of the present invention, relevant tests on the flexural strength and warpage data of the green bodies obtained in the above examples and comparative examples were respectively carried out, which can effectively show that the isolation layer method adopted by the present invention can effectively improve the strength of the green body and reduce the warpage. The test results are shown in Table 1 below.

[0094] Table 1. Fracture strength, warpage and difference between high and low points of each group of green body samples

[0095]

[0096] The green body contains a large amount of organic binder. Since multiple layers need to be stacked, the conventional methods of spraying and scraping the isolation layer are used to remove the binder from the green body at high temperature. During the debinding process of the green body, the organic matter around the green body cracks faster than that in the middle. The volatiles in the middle need to volatilize through the surrounding area, and this volatilization will cause uneven deposition and accumulation of particles during the debinding process, resulting in different degrees of stress, creep, and uneven voids. This leads to problems such as a large warpage degree and uneven densification of the substrate. As can be seen from Table 1, according to the flexural strength and warpage degree shown in Examples 1-5 and the data of Comparative Examples 1-2, compared with Comparative Example 1 prepared by conventional spraying and Comparative Example 2 prepared by conventional scraping, the green body strength obtained by the array rod-like structure boron nitride isolation layer prepared by the template method in Examples 1-5 has the following advantages: First, Examples 1-5 have higher flexural strength, indicating that the green body is more dense. Second, from the warpage degree data of Comparative Examples 1-2 and Examples 1-5, it can be seen that Examples 1-5 have lower warpage degrees, indicating that the stress distribution of the green body in all directions is uniform and the deformation amount of the green body is small. Finally, through the difference data of the highest point and the lowest point on the surface of the green body obtained in Comparative Examples 1-2 and Examples 1-5, it can be seen that the difference between the highest point and the lowest point in Examples 1-5 is about 0.01 mm, while the difference between the highest point and the lowest point in Comparative Examples 1-2 is about 0.02-0.03 mm. This shows that the difference between the highest point and the lowest point on the surface of Examples 1-5 is smaller, indicating better surface uniformity. Therefore, Examples 1-5 of the present invention have better advantages, which benefit from the array rod-like structure boron nitride isolation layer prepared by the template method providing channels for the cracking and volatilization of the organic matter in the green body, thereby making the stress distribution uniform and the surface volatilization pores uniform, improving the deformation caused by different stresses at each point and uneven particle deposition due to uneven volatilization of the ceramic green body, and thus obtaining a ceramic green body with high strength and high uniformity.

[0097] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for preparing a boron nitride isolation layer, characterized in that, It includes the following steps: Disperse boron nitride nanotubes and boron nitride rod-like fiber crystals in a solvent, add a binder and mix evenly, then pour it onto a porous high-silica borate glass template, scrape and coat the surface evenly, and after drying, obtain a boron nitride isolation layer with a rod-like array structure.

2. The preparation method of the boron nitride isolation layer according to claim 1, characterized in that The diameter of the boron nitride nanotubes is 10 - 30 nm and the length is 1 - 10 μm; the diameter of the boron nitride rod-like fiber crystals is 1 - 5 μm and the length is 50 - 300 μm.

3. The preparation method of the boron nitride isolation layer according to claim 1, characterized in that, The solvent is ethanol; the binder is polyvinylpyrrolidone.

4. The preparation method of the boron nitride isolation layer according to claim 1, characterized in that The thickness of the porous borosilicate glass template is 1-10 mm, the surface pore density is 50-100 pores / cm 2 , the pore diameter is 10-50 μm, and the pore depth is 10-100 μm.

5. The method for preparing a boron nitride isolation layer according to claim 1, wherein, The thickness of the surface scraping and coating is 25 - 100 μm.

6. The preparation method of the boron nitride isolation layer according to claim 1, wherein Dry under the condition of 65 - 70 °C.

7. Application of the boron nitride isolation layer prepared by the method described in claims 1 - 6 in the debinding of green ceramic bodies.

8. A method for debinding a ceramic green body, characterized in that, It includes the following steps: After stacking the boron nitride isolation layer prepared by the method described in claims 1 - 6 and the green ceramic body at intervals, clamp them with a backing plate and a cover plate for debinding; wherein the side of the boron nitride isolation layer with a rod-like array structure is in contact with the upper surface of the green ceramic body.

9. The ceramic green body debinding method according to claim 8, wherein The steps of debinding include the following: Under a nitrogen atmosphere, heat from room temperature to 200 - 230 °C at a rate of 0.5 - 2.5 °C / min, then heat to 400 - 430 °C at a rate of 0.1 - 1.0 °C / min, and then heat to 630 - 650 °C at a rate of 1.5 - 2.5 °C / min, and keep it at 630 - 650 °C for 1 - 2 h; Exclude nitrogen and introduce air, keep it at 630 - 650 °C under an air atmosphere for 3 - 4 h, and then cool to room temperature.

10. The method for preparing the green ceramic body according to claim 9, characterized in that, The air delivery air flow rate is not higher than 4 - 6 m / s.

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