WO2015003508A1

WO2015003508A1 - Highly insulating silicon carbide/boron nitride ceramic material and preparation method therefor

Info

Publication number: WO2015003508A1
Application number: PCT/CN2014/074001
Authority: WO
Inventors: 黄政仁; 李寅生; 闫永杰; 刘学建; 陈忠明
Original assignee: 中国科学院上海硅酸盐研究所
Priority date: 2013-07-12
Filing date: 2014-03-25
Publication date: 2015-01-15
Also published as: CN104276823B; CN104276823A

Abstract

The present invention relaters to a highly insulating silicon carbide/boron nitride ceramic material and a preparation process therefor. The ceramic material comprises silicon carbide, boron nitride generated by an in situ reaction and distributed uniformly on the crystal boundaries of the silicon carbide, and boron carbide and carbon which are used as sintering auxiliaries in the preparation of the ceramic material, wherein the ceramic material has the following contents by weight: above 90 wt% of silicon carbide, 0.5-10 wt% of boron nitride, 0.2-2.0 wt% of boron carbide, and 0.5-2.0 wt% of carbon. The highly insulating silicon carbide/boron nitride ceramic material provided in the present invention introduces a boron carbide phase by an in situ reaction and has a low carbon content, thereby improving the insulation performance of the silicon carbide ceramic and the comprehensive performance of the material.

Description

High-insulation silicon carbide/boron nitride ceramic material and preparation method thereof

技术领域 Technical field

The invention relates to a high insulation silicon carbide / A boron nitride ceramic material, in particular, relates to a normal pressure sintered silicon carbide ceramic comprising a boron nitride phase formed in situ and a production method thereof. The ceramic material has good thermal and electrical insulation properties, and is particularly suitable for heat dissipation applications in the field of electronic packaging.

背景技术 Background technique

Modern microelectronic systems and devices are rapidly developing in the direction of large-scale integration, miniaturization, high efficiency, and high reliability. The increase in integration will lead to an increase in power density and an increase in the amount of heat generated by the electronic components and the overall operation of the system, and heat dissipation becomes an important factor restricting development.

The ideal electronic packaging material should have the following characteristics: (1) high thermal conductivity. If it cannot be dissipated in time, it will affect the life and operation of electronic equipment. Uneven temperature distribution will also lead to a significant increase in noise of electronic devices; (2) It is similar to the thermal expansion coefficient of the chip material Si ((3.6~4.0)×10 ⁻⁶ /K) to ensure that the electronic device does not fail due to thermal stress; (3) It should have good electrical insulation performance and high mechanical properties. Chemical stability and other characteristics; (4) easy metallization; (5) low dielectric constant at 1MHz and higher.

At present, the most commonly used electronic packaging ceramic materials are mainly alumina ceramics, mainly because of its low cost, but its thermal conductivity is low, only (20-25 W / (m•K)), and its thermal expansion coefficient (7.2 ×10 ⁻⁶ /K) is relatively high for silicon single crystals and is limited in use in high frequency, high power, and very large scale integrated circuits. Aluminum nitride has high thermal conductivity (150~260W/(m•K)), and thermal expansion coefficient ((3.8~4.4)×10 ⁻⁶ /K) matches silicon material, but its preparation process is complicated, surface metal It is difficult to make, and the cost is high. So far, it has not been able to carry out large-scale production and application. Cerium oxide ceramics have the highest room temperature thermal conductivity (310W/(m•K)), but cerium oxide powder is highly toxic, which limits its production and application.

Silicon carbide ceramics have the closest thermal expansion coefficient (3.7×10 ^-6 /K) to silicon, and the temperature change rate is similar at room temperature to 1000 °C. In addition, SiC ceramics have good oxidation and corrosion resistance, high thermal conductivity (80~170W/(m•K)) and thermal shock resistance. Moreover, the preparation process is simple, and the production cost is much lower than that of aluminum nitride. However, the resistivity of the silicon carbide ceramic material is generally ^{^{10 2 ~ 10 6 Ω • cm}} , the dielectric loss, can not meet the requirements of the electronic package. How to improve the electrical insulation properties of silicon carbide ceramics without reducing its high thermal conductivity and satisfying the application of electronic packaging components has become an urgent problem for researchers.

Patent US4370421 firstly gave a high-insulation silicon carbide ceramic material with 0.1-3.5% yttrium oxide as a sintering aid with a resistivity of 10 ¹⁰ Ω•cm or more. However, the toxicity of cerium oxide powder greatly limits the application of this material.

Patent US7989380B2 shows a silicon carbide/silicon nitride ceramic material prepared by a reaction hot pressing process with a sintering temperature of 2100 ° C / 20 MPa, using silicon carbide, silicon oxide, silicon nitride and boron carbide as raw materials, and a resistivity of 10 ¹⁰ Ω•cm or so, mainly used for plasma etching of cavity materials.

Patent JP 2003-277152 provides a silicon carbide ceramic material prepared by hot press sintering, containing 0.5-4 mass% free carbon, 1-20 mass% boron nitride, and a material resistivity exceeding 10 ⁸ Ω•cm.

Patent JP2001-352223 provides a SiC ceramic material prepared by hot press sintering, containing 1-10% by mass Boron nitride, free carbon below 100PPM. However, the sintering density is lower than 90% T.D, and the ceramic material needs to be purified in a high temperature argon atmosphere.

Patent US6764974B2 provides a reaction hot pressing process for preparing silicon carbide / Boron nitride ceramic material, using silicon nitride, boron carbide and carbon as raw material powder, alumina and cerium oxide as sintering aids, sintering temperature up to 2000 °C / 50MPa . The prepared ceramic material has a reduced modulus of elasticity and strength, so that the material has good processability.

Patent US4701427 provides a normal-pressure sintered silicon carbide ceramic material using a sintering aid of 2.5% by mass of carbon, 0.4-2.0% by mass of boron carbide, and boron nitride or aluminum as a sintering aid. The ceramic material prepared by the process has a resistivity higher than 10 ⁸ Ω•cm and a density higher than 2.95 g/cm ³ . However, the sintering temperature is above 2250 ° C and a nitrogen atmosphere is used.

Patent US4762810 provides a normal-pressure sintered silicon carbide ceramic material using a boron/carbon system as a sintering aid, sintered at a high temperature of 1800-2200 ° C, and a material having a resistivity higher than 10 ¹⁰ Ω•cm and a thermal conductivity exceeding 150. W/(m•K), but the powder used is a nano-silicon carbide powder synthesized by gas phase method. BN is used as a buried powder in the sintering process, which has higher cost and has no greater advantage than aluminum nitride.

Patent US7166550B2 provides a normal pressure sintered silicon carbide / boron nitride / carbon composite ceramic in which the boron nitride content is 3 The mass is about %, the average particle size is more than 10 microns, and the wear resistance of the material is greatly improved compared to the single-phase silicon carbide ceramic.

Patent CN200610050438.6 provides a normal pressure sintered silicon carbide / Boron nitride ceramic composite material, in which the boron nitride content is more than 2% and the average particle diameter is 5-400 micrometers, the material has good wear resistance and can be well applied in the field of wear resistance.

Patent CN201010538042.2 provides a normal-pressure sintered silicon carbide ceramic seal, wherein the content of boron nitride is 5-10%, the sintering aid used is molybdenum disulfide and yttrium aluminum garnet, high temperature liquid phase sintering. The material has a low coefficient of friction, good thermal and mechanical properties.

Patent CN201010192096.8 A silicon carbide ceramic material is provided, wherein the content of boron nitride is 5-30%. The aluminum content is 5-50%, which is prepared by plasma activation sintering process and is a good machinable ceramic.

Patent CN201210488170.X provides a cubic boron nitride / The silicon carbide multiphase ceramic material is prepared by a process of silicon infiltration by using boron nitride powder as a main raw material, and the material can be used as a superhard material in the field of wear resistance.

It can be seen that the introduction of the boron nitride phase improves the insulation properties of the silicon carbide ceramic to some extent, but most of them adopt the hot press sintering or the reaction sintering process to achieve high densification. If the atmospheric pressure sintering process is used, high-density and high-insulation ceramic materials are required, and the requirements on the powder are relatively high. Generally, nano-powders are required, and high-temperature sintering in a nitrogen atmosphere is required, which limits the low to a certain extent. Cost preparation, the overall cost performance of materials has not improved. Currently for silicon carbide / Research on boron nitride atmospheric pressure sintered materials is mostly concentrated in the field of wear-resistant and machinable ceramics, and generally contains a high carbon content. It is foreseeable that the insulating properties of materials are not high and cannot be applied to the field of electronic packaging.

In summary, in boron nitride - In the preparation of silicon nitride ceramic materials, there is no effective atmospheric pressure sintering process to achieve high insulation properties of the material, and high thermal conductivity. It is urgent to develop such materials to meet the current field of electronic packaging. Applications. In particular, once the preparation of such materials is achieved, the cost in the field of electronic packaging will be greatly reduced, and has important market value.

发明内容 Summary of the invention

In view of the problems existing in the prior art, the present invention aims to provide a novel high-insulation silicon carbide/boron nitride ceramic material. To meet the current application in the field of electronic packaging.

Here, the present invention first provides high insulating silicon carbide / a boron nitride ceramic material comprising silicon carbide, boron nitride uniformly distributed at a silicon carbide grain boundary by an in-situ reaction, and boron carbide and carbon as a sintering aid in the preparation of the ceramic material , wherein the content of silicon carbide in the ceramic material is by weight 90% by weight or more, the content of boron nitride is 0.5 to 10% by mass, the content of boron carbide is 0.2 to 2.0% by mass, and the content of carbon is 0.5 to 2.0% by mass. .

Highly insulating silicon carbide provided by the present invention / The boron nitride ceramic material introduces a boron carbide phase by in-situ reaction, and has a low carbon content, improves the insulation performance of the silicon carbide ceramic, and improves the overall performance of the material, for example, a higher resistivity than a single-phase silicon carbide ceramic. Lower dielectric constant and loss, and high thermal conductivity, especially suitable for heat dissipation applications in the field of electronic packaging.

Preferably, the boron nitride content may be 1 to 8 mass%, and the boron carbide content may be 0.4 to 1.0 mass%. The carbon content may be from 0.8 to 1.8% by mass.

Preferably, the ceramic material has a relative density of 90% TD or more, preferably 95% TD or more; and a thermal conductivity of 60 to 100 W·m ^-1 · K ^-1 , preferably 80 to 100 W·m ^-1 . K ^-1 ; DC resistivity may be 10 ⁸ to 10 ¹³ Ω·cm, preferably 10 ¹⁰ to 10 ¹² Ω·cm.

Preferably, the ceramic material has a dielectric constant at 1 MHz of 15 to 100, preferably 15 to 30. The loss tangent may be from 0.100 to 0.900, preferably from 0.100 to 0.300.

Preferably, the boron nitride has an average particle diameter of 0.1 to 4.0 μm.

The present invention also provides a method of preparing the above high-insulation silicon carbide/boron nitride ceramic material, the method may include:

(a) Take (80 to 98)% by mass of silicon carbide powder, (0.7 to 11.2) by mass % a silicon nitride powder, (0.6 to 5.2) mass% of boron carbide, and (1.5 to 3.5) mass% of a carbon source, and (0 to 2.0) mass % of a dispersant, 0.2 to 10) mass% of the binder and solvent are ball milled, dried, pre-compressed and then isostatically pressed;

(b) heating the green body obtained in step (a) at 600 ~ 1000 °C for 1 to 4 hours, then 1500 ~ 1800 °C, heat treatment in nitrogen atmosphere for 4 ~ 8 hours for in-situ reaction to form boron nitride;

(c) argon-protected and sintered at 1900~2300 °C for 1 to 4 hours;

(d) Annealing the ceramic material obtained in step (c) at 1600 ~ 2100 °C under argon atmosphere 0 ~ 16 hours.

( a' ) SiC powder, boric acid, urea by mass ratio (90 ~ 98): (1.2 ~ 20): (2.5 ~ 60) performing batching, ball milling mixing, drying, and pre-forming;

( b' ) The green body obtained in the step ( a ' ) is heat treated at 800 to 1000 ° C in a nitrogen atmosphere 8 to 24 In-situ reaction to form boron nitride in the hour, or the raw material obtained in the step (a') is heat-treated in an ammonia gas atmosphere at 700 to 1000 ° C for 1 to 4 hours to form boron nitride in situ;

(c') grinding the body obtained in the step (b') into a powder, taking (98.9 to 97.2) by mass, by weight The powder is compounded with (0.3 to 1.0)% by mass of boron carbide powder and (0.8~1.8)% by mass of carbon source, and (0 to 2.0)% by mass of dispersant is added ( 0.2 to 10) mass% of the binder and solvent are ball milled, dried, pre-compressed and then isostatically pressed;

(d') is argon-protected and sintered at 1900~2300 °C for 1 to 4 hours;

( e ' ) The ceramic material obtained in step ( d ' ) is annealed at 1600 to 2100 ° C under an argon atmosphere 0 ～ 16 hours.

Preferably, the step (a') is: silicon carbide powder, boric acid, urea by mass ratio (90 to 98): (1.2 to 20) ): (2.5 ~ 40) for batching, ball milling, drying, pre-forming; and step (b') is: the raw material obtained in step (a') is 700 ~ 1000 °C The in-situ reaction is carried out in an ammonia gas atmosphere for 1 to 4 hours to form boron nitride.

The use of ammonia as the in-situ reaction heat treatment atmosphere can lower the heat treatment temperature and significantly reduce the heat treatment time.

Preferably, the carbon source may be elemental carbon or cracked organic matter capable of producing elemental carbon.

The method of the invention adopts pressureless sintering and combines the method of in-situ reaction to ensure uniform internal structure of the sintered body and high production efficiency; further reducing the particle size of the boron nitride to the nanometer level on the basis of ensuring uniform dispersion, and improving The thermal and electrical properties of the composite; the silicon carbide/boron nitride ceramic composite obtained by sintering without pressure sintering aid has a density of about 90% TD and a thermal conductivity of 60~100 W·m ^-1 ·K ^-1 . The room temperature to 400 ° C thermal expansion coefficient is 3.26 × 10 ^-6 / ° C, DC resistance is 10 ⁸ ~ 10 ¹³ Ω · cm, the dielectric constant at 1MHz is 15 ~ 100, loss tangent is 0.100 ~ 0.900.

附图说明 DRAWINGS

Figure 1 is a schematic diagram showing the process flow of the method for preparing a silicon carbide/boron nitride ceramic composite.

Figure 2 is a schematic diagram of the process flow for preparing a silicon carbide/boron nitride ceramic composite by the second method.

Figure 3 is an X-ray diffraction diagram of a silicon carbide/boron nitride ceramic composite of the present invention.

Figure 4 is a micro-structure of a polished surface of a silicon carbide/boron nitride ceramic composite prepared by the method of Example 1.

Figure 5 shows the microstructure of an example polished surface of a silicon carbide/boron nitride ceramic composite prepared by the second method after hot etching.

具体实施方式 detailed description

Hereinafter, the present invention will be further described with reference to the drawings and the following embodiments. The drawings are to be construed as illustrative only and not limiting.

The invention uses silicon nitride / boron carbide / carbon and boric acid / urea / The silicon carbide/boron nitride ceramic composite material is prepared by introducing a boron nitride phase, a normal pressure sintering and a high temperature annealing process by in-situ reaction of carbon as a raw material. First, referring to Figure 1, there is shown the preparation of the silicon carbide of the present invention / A method of boron nitride ceramic composite material comprising the following steps:

( 1 a certain amount of silicon carbide powder is added to the in-situ reaction raw material, sintering aid, dispersant, binder and solvent, and uniformly mixed in a planetary ball mill to prepare a slurry;

(2) The slurry is placed in an oven for drying, then crushed and sieved, and a small amount of the sample is placed in a mold for pre-compression molding, followed by isostatic pressing;

(3) heating and debonding the formed body in a vacuum resistance furnace, the heat treatment temperature is 600~1000 ° C, and the holding time is 1~4 hours, the heating rate is 1~5 °C/min;

(4) The invented body is subjected to in-situ reaction in a high temperature furnace at a heat treatment temperature of 1500 to 1800 ° C and a holding time of 4 to 8 Hour, the heating rate is 1~10 °C / min, nitrogen atmosphere;

(5) The in-situ reaction body is sintered in a high-temperature furnace at a sintering temperature of 1900 to 2300 ° C and a holding time of 1 to 4 Hour, the heating rate is 1~10 °C / min, argon atmosphere;

(6) The sintered ceramic is annealed in a high temperature furnace at an annealing temperature of 1600 to 2100 ° C and a holding time of 0 to 16 Hours, the cooling rate is 1~10 °C / min, argon atmosphere.

The in situ reaction starting material is Si ₃ N ₄ -B ₄ CC . Between the silicon carbide powder and the in-situ reaction raw material, the total mass of Si ₃ N ₄ -B ₄ CC is 100%, and (80 to 98% by mass of silicon carbide powder, (0.7 to 11.2) mass% of nitrogen is taken. Silicon carbide powder, (0.6 to 5.2)% by mass of boron carbide and (1.5 to 3.5)% by mass of carbon source are mixed, and the BN content generated by in-situ reaction is 0.5 to 10% by mass, preferably 1 to 8 Quality %. Situ reaction after the starting material is Si ₃ N _₄ -B ₄ CC B ₄ CC further in as sintering aids, participated in situ stoichiometric reaction, the remaining B ₄ C content of 0.2 to 2.0 mass%, preferably in an amount 0.4 ~1.0% by mass, the content of the remaining C is 0.5 to 2.0% by mass, and the preferred content is 0.8 to 1.8% by mass, wherein the introduction mode of C may be an elemental powder, such as nanocarbon black, or may be produced by cracking of an organic substance, for example, by Partial cracking of the phenolic resin as a binder is produced.

The type of the dispersing agent may be polyethylene glycol, polyethyleneimine or polymethylammonium methacrylate, and the content thereof may be 0 to 2.0 mass%. The preferred content is 0 to 1.0% by mass.

The type of the binder may be polyvinyl butyral or phenolic resin, and the content thereof may be 0.2 to 10% by mass, and the preferred content is 0.5~6 mass %.

The above isostatic pressing pressure can be 150~300MPa, and the optimized pressure is 160~250MPa.

Referring to FIG. 4, the silicon carbide prepared by the above method 1 is shown. Boron nitride ceramic composite material, the microstructure of the polished surface after hot corrosion. It can be seen that the average particle size of silicon carbide is about 3 to 4 μm, and a small amount of pores appear.

Referring to Figure 2, there is shown yet another method of preparing a silicon carbide/boron nitride ceramic composite of the present invention comprising the steps of:

(1) adding a certain amount of silicon carbide powder to the in-situ reaction raw material and anhydrous ethanol, and uniformly mixing in a planetary ball mill to prepare a slurry;

(2) The slurry is dried in an oven, and then crushed and sieved, and a small amount of the sample is placed in a mold for pre-forming, The obtained green body can be subjected to a heat treatment in situ under a nitrogen or ammonia atmosphere, for example, at 800 to 1000 ° C in a nitrogen atmosphere for 8 to 24 hours, preferably 1 to 16 hours, for example, 700 to 1000 ° C, heat treatment in an ammonia atmosphere for 1 to 4 hours for in-situ reaction to form boron nitride; preferably in a ammonia atmosphere for heat treatment, can significantly reduce the heat treatment time and can appropriately reduce the heat treatment temperature ;

(3 Re-grinding the heat-treated body, and then adding a sintering aid, a dispersing agent, a binder and absolute ethanol, and uniformly mixing in a planetary ball mill to obtain a slurry;

(4) heating and debonding the formed body in a vacuum resistance furnace, the heat treatment temperature is 600 to 1000 ° C, and the holding time is 1 to 4 hours, the heating rate is 1 ~ 5 °C / min;

(5) The heat-treated body is sintered in a high-temperature furnace at a sintering temperature of 1900 to 2300 ° C and a holding time of 1 to 4 Hour, the heating rate is 1 ~ 10 ° C / min, argon atmosphere;

(6) The sintered ceramic is annealed in a high temperature furnace at an annealing temperature of 1600 to 2100 ° C and a holding time of 0 to 16 Hours, the cooling rate is 1 ~ 10 ° C / min, argon atmosphere.

The in-situ reaction raw materials are boric acid and urea, and the silicon carbide powder, boric acid and urea can be mass ratio (90 to 98): (1.2 ～ 20): (2.5 to 60) for ingredients. The BN content generated by the in-situ reaction is 0.5 to 10% by mass, and the optimum content is 1 to 8% by mass. . The ratio of the amount of boric acid to urea is 1:1 to 1:8, and the optimum ratio is 1:2 to 1:4.

The sintering aid may include B ₄ CC , BC , wherein the introduction mode of C may be an elemental carbon powder, such as nano carbon black, or may be produced by cracking of an organic substance, for example, a part of a phenolic resin which also serves as a binder. Cracking is produced. Wherein the content of B or B ₄ C in 0.2 to 2.0 mass%, the content is preferably 0.4 to 1.0 mass%, the residual C content is 0.5 to 2.0 mass%, the content is preferably 0.8 to 1.8 mass%.

The isostatic pressing pressure may be 150 to 300 MPa, and the optimized pressure is 160 to 250 MPa.

Referring to FIG. 5, the silicon carbide prepared by the above method 2 is shown. Boron nitride ceramic composite material, the microstructure of the polished surface after hot corrosion. It can be seen that the average particle size of silicon carbide is about 2 to 3 μm, and a small amount of pores appear.

The invention has the following advantages:

( 1 Using pressureless sintering combined with in-situ reaction method, a certain amount of hexagonal boron nitride particles are formed in the silicon carbide matrix, and boron nitride is uniformly dispersed in the sintered body, thereby ensuring uniform internal structure of the sintered body and high production efficiency. ;

(2) Method 1 adopts an integrated method of in-situ reaction and high-temperature sintering, which avoids secondary mixing and molding, and has high production efficiency;

(3 The second method further reduces the particle size of boron nitride to the nanometer level on the basis of ensuring uniform dispersion, and improves the thermal and electrical properties of the composite material.

The silicon carbide/boron nitride ceramic composite material obtained by sintering the pressureless sintering aid has uniform and compact structure, and the density reaches about 90% TD, and even reaches 95% TD or more; the thermal conductivity is excellent, and the thermal conductivity reaches 60 ～. 100W·m ^-1 ·K ^-1 , for example, 80 ~ 100W · m ^-1 · K ^-1 ; The thermal expansion coefficient is 3.26 × 10 ^-6 / °C from room temperature to 400 ° C; the resistivity is close to the insulator level, and the DC resistivity is 10 ⁸ ～ 10 ¹³ Ω·cm , preferably 10 ¹⁰ ～ 10 ¹² Ω·cm ; low dielectric constant and loss value; dielectric constant at 1 MHz is 15 to 100, preferably 15 to 30, loss tangent is 0.100 to 0.900 Preferably, it is 0.100 to 0.300. It can be seen that the ceramic material of the invention has higher resistivity, lower dielectric constant and loss than the single-phase silicon carbide ceramic, and has high thermal conductivity, and is particularly suitable for heat dissipation applications in the field of electronic packaging.

The invention is further illustrated by the following examples to better illustrate the invention. It is to be understood that the following examples are only intended to illustrate the invention and are not to be construed as limiting the scope of the invention, and that some non-essential improvements and modifications made by those skilled in the art in light of the The scope of protection. The experimental methods in the following examples which do not specify the specific conditions are usually in accordance with conventional conditions.

Example 1

The flow chart of the preparation process of high-insulation silicon carbide/boron nitride ceramic composite is shown in Fig. 1: SiC powder with mass percentage of 95.7 mass%, Si ₃ N ₄ powder of 1.4 mass%, 1.16 mass% of B ₄ C powder, 1.74% by mass of nano-carbon black, 0.5% by mass of the polyethylenimine, 1% by mass of polyvinyl butyral and ethanol mixed and milled 4h, formulated solids content of 50% of pulp material. The slurry was then dried in a 60 ° C oven for 4 h, crushed and screened for particles below 100 mesh. The appropriate amount of powder is placed in a mold for pre-compression molding, and then isostatically pressed. The formed green body was heated in a vacuum resistance furnace to 600 ° C for 4 hours for heat treatment at a heating rate of 5 ° C / min. Then, it was reacted in situ in a nitrogen atmosphere at 1700 ° C for 1 hour in a high temperature furnace at a heating rate of 10 ° C /min. Finally, it was sintered in an argon atmosphere at 2160 ° C for 1 hour in a high temperature furnace at a heating rate of 10 ° C / min. After sintering, the relative density of the composite is 99.38% TD, the thermal conductivity is 79.39 W·m ^-1 ·K ^-1 , the resistivity is 1.83×10 ⁸ Ω·cm , and the dielectric constant at 1 MHz is 88.46. The value is 0.724.

Example 2

SiC powder having a mass percentage of 90.9% by mass, 4.2% by mass of Si ₃ N ₄ powder, 2.5% by mass of B ₄ C powder, 0.5% by mass of polymethyl methacrylate, 4% by mass of phenol resin and Anhydrous ethanol was mixed and ball milled for 4 h. The slurry was then placed in a 60 ° C oven for 4 h, crushed and screened. A small amount of sample was placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 800 ° C for 2 hours for heat treatment at a heating rate of 2 ° C / min. Then, it was kept at a temperature of 1,650 ° C for 2 hours in a high-temperature furnace at a heating rate of 5 ° C /min. Finally, it was sintered in an argon atmosphere at 2170 ° C for 1 hour in a high temperature furnace at a heating rate of 5 ° C /min. After sintering, the composite has a relative density of 99.21% TD, a thermal conductivity of 72.17 W·m ^-1 ·K ^-1 , a resistivity of 9.13 × 10 ⁸ Ω·cm , a dielectric constant of 66.45 at 1 MHz , and a loss tangent The value is 0.594.

Example 3

SiC powder having a mass percentage of 87.1% by mass, 7% by mass of Si ₃ N ₄ powder, 3.2% by mass of B ₄ C powder, 2.7% by mass of nano carbon black, and 1% by mass of polyethylene glycol, 1% by mass of polyvinyl butyral and absolute ethanol were mixed and ball milled for 8 h. The slurry was then placed in a 40 ° C oven for 8 h, crushed and screened. A small amount of sample was placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 800 ° C for 1 hour for heat treatment at a heating rate of 3 ° C / min. Then, it was kept at a temperature of 1600 ° C for 4 hours in a high-temperature furnace at a heating rate of 5 ° C /min. Finally, it was sintered in an argon atmosphere at 2180 ° C for 2 hours in a high temperature furnace at a heating rate of 10 ° C /min. The sintered composite has a relative density of 99.12% TD, a thermal conductivity of 72.78 W·m ^-1 ·K ^-1 , a resistivity of 5.93 × 10 ⁹ Ω·cm , and a dielectric constant of 42.82 at 1 MHz. The tangent value is 0.603.

Example 4

The mass percentage is 89% by mass of SiC powder, 5.6 % by mass of Si ₃ N ₄ powder, 3 % by mass of B ₄ C powder, 1% by mass of polymethyl methacrylate, 4% by mass of phenolic resin, and Anhydrous ethanol was mixed and ball milled for 4 h. The slurry was then placed in a 40 ° C oven for 8 h, crushed and screened. A small amount of sample was placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 800 ° C for 1 hour for heat treatment at a heating rate of 2 ° C / min. In a high temperature furnace, the nitrogen atmosphere was kept at 1600 ° C for 4 hours, and the heating rate was 10 ° C / min. Then, it was sintered in an argon atmosphere at 2150 ° C for 2 hours in a high-temperature furnace at a heating rate of 5 ° C /min. After the sintering is completed, annealing is performed at 1600 ° C for 6 h, and the cooling rate is 10 ° C / min. The resulting composite has a relative density of 98.47% TD, a thermal conductivity of 76.36 W·m ^-1 ·K ^-1 , a resistivity of 1.32 × 10 ⁹ Ω·cm , and a dielectric constant of 40.31 at 1 MHz. The tangent value is 0.405.

Example 5

SiC powder having a mass percentage of 84.7 mass%, 8.4 mass% of Si ₃ N ₄ powder, 3.9 mass% of B ₄ C powder, 1 mass% of polyethyleneimine, 5 mass% of phenol resin, and none The water was mixed with ethanol and ball milled for 16 h. The slurry was then placed in a 60 ° C oven for 4 h, crushed and screened. A small amount of sample was placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 800 ° C for 1 hour for heat treatment at a heating rate of 2 ° C / min. In a high temperature furnace, the nitrogen atmosphere was kept at 1,650 ° C for 3 hours, and the heating rate was 10 ° C / min. It was further sintered at 2170 ° C for 2 hours in a high-temperature furnace at a temperature of 3 ° C /min. After the sintering was completed, it was annealed at 1900 ° C for 4 h, and the cooling rate was 5 ° C / min. The resulting composite has a relative density of 98.81% TD, a thermal conductivity of 76.36 W·m ^-1 ·K ^-1 , a resistivity of 1.69 × 10 ¹⁰ Ω·cm , and a dielectric constant of 26.47 at 1 MHz. The tangent value is 0.198.

Example 6

The mass percentage is 80.3 mass% of SiC powder, 11.2 mass% of Si ₃ N ₄ powder, 5.2 mass% of B ₄ C powder, 0.5 mass % of polymethyl methacrylate, 5.5 mass % of phenol resin, and Absorbed in absolute ethanol and ball milled for 8 h. The slurry was then placed in a 30 ° C oven for 8 h, crushed and screened. A small amount of sample was placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 600 ° C for 4 hours for heat treatment, and the heating rate was 3 ° C / min. In a high temperature furnace, the nitrogen atmosphere was kept at 1600 ° C for 4 hours, and the heating rate was 5 ° C / min. Then, it was sintered in an argon atmosphere at 2,200 ° C for 2 hours in a high-temperature furnace at a heating rate of 3 ° C /min. After the sintering is completed, it is annealed at 1800 ° C for 6 h, and the cooling rate is 3 ° C / min. The resulting composite has a relative density of 95.63% TD, a thermal conductivity of 67.89 W·m ^-1 ·K ^-1 , a resistivity of 2.15 × 10 ¹¹ Ω·cm , a dielectric constant of 16.36 at 1 MHz, and a loss angle. The tangent value is 0.121.

Example 7

The flow chart of the preparation process of the high-insulation silicon carbide-boron nitride nanocomposite is shown in Fig. 2: SiC powder with a mass percentage of 96.9 mass%, 2.48 mass% boric acid, 6 mass% urea and absolute ethanol mixed And ball milled for 2 hours. The slurry was then placed in a 60 ° C oven for 8 h, crushed and screened. A proper amount of the sample was placed in a mold and pre-compressed, and held in a high-temperature furnace at a temperature of 800 ° C for 16 hours, and the heating rate was 10 ° C / min. The sample was then crushed and screened, followed by addition of 0.3% by mass of B ₄ C powder, 1.3% by mass of nano carbon black, 1% by mass of polyethylene glycol, 1% by mass of polyvinyl butyral and anhydrous The ethanol was mixed and ball milled for 4 h. The slurry was placed in a 60 ° C oven for 4 h, crushed and screened. A suitable amount of the sample is placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 600 ° C for 2 hours for heat treatment at a heating rate of 5 ° C / min. Finally, it was sintered in an argon atmosphere at 2140 ° C for 2 hours in a high temperature furnace at a heating rate of 10 ° C /min. The sintered composite has a relative density of 98.82% TD, a thermal conductivity of 86.48 W·m ^-1 ·K ^-1 , a resistivity of 2.64 × 10 ¹⁰ Ω·cm , and a dielectric constant of 90.41 at 1 MHz. The tangent value is 0.608.

Example 8

SiC powder having a mass percentage of 95.9 mass%, 4.96 mass% of boric acid, 12 mass% of urea and absolute ethanol were mixed and ball milled for 2 hours. The slurry was then placed in a 60 ° C oven for 8 h, crushed and screened. A proper amount of the sample was placed in a mold for pre-compression molding, and the temperature was maintained at 850 ° C for 16 hours in a high-temperature furnace at a heating rate of 10 ° C / min. The sample was then crushed and sieved, and then 0.9% by mass of B ₄ C powder, 0.5% by mass of polyethyleneimine, 2.8% by mass of phenolic resin, 0.5% by mass of polyvinyl butyral and absolute ethanol were added. Mix and ball mill for 4h. The slurry was placed in a 60 ° C oven for 4 h, crushed and screened. A proper amount of the sample is placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 900 ° C ° C for 1 hour for heat treatment, and the heating rate is 3 ° C / min. Finally, it was sintered in an argon atmosphere at 2150 ° C for 2 hours in a high temperature furnace at a heating rate of 10 ° C /min. The relative density of the composite after sintering 98.47% TD, a thermal conductivity of 83.21W · m ^{^-1} · K ^-1, a resistivity of 8.95 × ¹⁰ 10 Ω · cm, dielectric constant at 1MHz is 68.04, tan The tangent value is 0.512.

Example 9

SiC powder having a mass percentage of 90% by mass, 19.84% by mass of boric acid, 57.6 mass% of urea and absolute ethanol were mixed and ball milled for 2 hours. The slurry was then placed in a 30 ° C oven for 12 h, crushed and screened. A proper amount of the sample was placed in a mold for pre-compression molding, and the temperature was maintained at 850 ° C for 32 hours in a high-temperature furnace at a heating rate of 3 ° C / min. The sample was then crushed and screened, and then 0.5% by mass of B ₄ C powder, 1% by mass of polyammonium methacrylate, 1.5% by mass of phenolic resin, 0.5% by mass of polyvinyl butyral and anhydrous The ethanol was mixed and ball milled for 8 h. The slurry was then placed in a 40 ° C oven for 8 h, crushed and screened. An appropriate amount of the sample is placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 900 ° C for 1 hour for heat treatment at a heating rate of 2 ° C / min. Finally, it was sintered in an argon atmosphere at 2,200 ° C for 1 hour in a high temperature furnace at a heating rate of 5 ° C /min. The sintered composite has a relative density of 95.98% TD, a thermal conductivity of 63.83 W·m ^-1 ·K ^-1 , a resistivity of 4.56 × 10 ¹² Ω·cm , and a dielectric constant of 36.74 at 1 MHz. The tangent value is 0.367.

Example 10

SiC powder having a mass percentage of 93.9 mass%, 9.92 mass% of boric acid, 38.4 mass% of urea and absolute ethanol were mixed and ball milled for 2 hours. The slurry was then placed in a 60 ° C oven for 8 h, crushed and screened. A proper amount of the sample was placed in a mold for pre-compression molding, and the temperature was maintained at 900 ° C for 48 hours in a high temperature furnace at a temperature of 5 ° C / min. The sample was then crushed and screened, and then 0.4% by mass of B ₄ C powder, 1% by mass of polyethyleneimine, 2.7% by mass of phenolic resin, 0.5% by mass of polyvinyl butyral and absolute ethanol were added. Mix and ball mill for 8h. The slurry was then placed in a 30 ° C oven for 12 h, crushed and screened. An appropriate amount of the sample is placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 900 ° C for 2 hours for heat treatment at a heating rate of 1 ° C / min. Finally, it was sintered in an argon atmosphere at 2170 ° C for 2 hours in a high temperature furnace at a heating rate of 5 ° C /min. After the sintering is completed, it is annealed at 2000 ° C for 4 h, and the cooling rate is 10 ° C / min. The resulting composite has a relative density of 98.61% TD, a thermal conductivity of 89.45 W·m ^-1 ·K ^-1 , a resistivity of 4.37 × 10 ¹¹ Ω·cm , and a dielectric constant of 27.36 at 1 MHz. The tangent value is 0.189.

Example 11

SiC powder having a mass percentage of 91.9 mass%, 14.88 mass% of boric acid, 50.4 mass% of urea and absolute ethanol were mixed and ball milled for 4 hours. The slurry was then placed in a 30 ° C oven for 12 h, crushed and screened. A proper amount of the sample was placed in a mold for pre-compression molding, and the temperature was maintained at 950 ° C for 36 hours in a high temperature furnace at a temperature increase rate of 2 ° C / min. The sample was then crushed and screened, followed by addition of 0.4% by mass of B ₄ C powder, 1% by mass of carbon black, 1% by mass of polyammonium methacrylate, 1% by mass of polyvinyl butyral and anhydrous The ethanol was mixed and ball milled for 8 h. The slurry was then placed in a 30 ° C oven for 12 h, crushed and screened. A proper amount of the sample is placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 600 ° C for 4 hours for heat treatment at a heating rate of 3 ° C / min. Finally, it was sintered in an argon atmosphere at 2180 ° C for 2 hours in a high temperature furnace at a heating rate of 5 ° C /min. After the sintering was completed, it was annealed at 1900 ° C for 6 h, and the cooling rate was 3 ° C / min. The resulting composite has a relative density of 98.05% TD, a thermal conductivity of 91.62 W·m ^-1 ·K ^-1 , a resistivity of 8.28 × 10 ¹¹ Ω·cm , a dielectric constant of 23.21 at 1 MHz, and a loss angle. The tangent value is 0.175.

Example 12

SiC powder having a mass percentage of 90.9% by mass, 17.36% by mass of boric acid, 50.4% by mass of urea and absolute ethanol were mixed and ball milled for 4 hours. The slurry was then placed in a 30 ° C oven for 12 h, crushed and screened. A proper amount of the sample was placed in a mold for pre-compression molding, and the temperature was maintained at 900 ° C for 48 hours in a high-temperature furnace at a temperature of 5 ° C / min. The sample was then crushed and screened, and then 0.6% by mass of B ₄ C powder, 1% by mass of polyethyleneimine, 2% by mass of phenolic resin, 1% by mass of polyvinyl butyral and absolute ethanol were added. Mix and ball mill for 4h. The slurry was then placed in a 30 ° C oven for 12 h, crushed and screened. A proper amount of the sample is placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 1000 ° C for 1 hour for heat treatment at a heating rate of 2 ° C / min. Finally, it was sintered in an argon atmosphere at 2180 ° C for 2 hours in a high temperature furnace at a heating rate of 3 ° C /min. After sintering, annealing at 1950 ° C for 6 h, the cooling rate is 5 ° C / min. The relative density of the resulting composite material was 97.75% TD, a thermal conductivity of 81.58W · m ^{^-1} · K ^-1, a resistivity of 1.33 × 10 ¹² Ω · cm, dielectric constant at 1MHz 21.85, loss angle The tangent value is 0.155.

Example 13

SiC powder having a mass percentage of 92% by mass, 14.88% by mass of boric acid, 28.8% by mass of urea and absolute ethanol were mixed and ball milled for 4 hours. The slurry was then dried in a 50 ° C oven for 12 h, crushed and screened. A proper amount of the sample was placed in a mold for pre-compression molding, and the temperature was maintained at 900 ° C for 2 hours in a tube furnace at a temperature of 5 ° C / min. The sample was then crushed and screened, followed by 0.5% by mass of B ₄ C powder, 1.5% by mass of nano carbon black, 1% by mass of polyethylene glycol, 1% by mass of polyvinyl butyral and anhydrous The ethanol was mixed and ball milled for 6 h. The slurry was placed in an oven at 80 ° C for 12 h, crushed and sieved. A proper amount of the sample is placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 600 ° C for 2 hours for heat treatment at a heating rate of 2 ° C / min. Finally, it was sintered in an argon atmosphere at 2160 ° C for 2 hours in a high temperature furnace at a heating rate of 5 ° C /min. The sintered composite has a relative density of 99.3% TD, a thermal conductivity of 76.37 W·m ^-1 ·K ^-1 , a resistivity of 5.88 × 10 ¹⁰ Ω·cm , and a dielectric constant of 19.22 at 1 MHz. The tangent value is 0.187.

Example 14

The mass percentage of 94% by mass of SiC powder, 9.92% by mass of boric acid, 14.4% by mass of urea and absolute ethanol were mixed and ball milled for 2 hours. The slurry was then placed in a 60 ° C oven for 8 h, crushed and screened. A proper amount of the sample was placed in a mold for pre-compression molding, and the ammonia gas atmosphere was kept at 700 ° C for 4 hours in a tube furnace at a heating rate of 3 ° C / min. The sample was then crushed and screened, followed by addition of 0.9% by mass of B ₄ C powder, 1% by mass of polyethyleneimine, 2.7% by mass of phenolic resin, 0.5% by mass of polyvinyl butyral and absolute ethanol. Mix and ball mill for 2h. The slurry was then placed in a 30 ° C oven for 12 h, crushed and screened. An appropriate amount of the sample is placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 800 ° C for 1 hour for heat treatment at a heating rate of 2 ° C / min. Finally, it was sintered in an argon atmosphere at 2150 ° C for 2 hours in a high temperature furnace at a heating rate of 5 ° C /min. After sintering, annealing at 1800 ° C for 8 h, the cooling rate is 5 ° C / min. The resulting composite has a relative density of 99.4% TD, a thermal conductivity of 85.73 W·m ^-1 ·K ^-1 , a resistivity of 6.29 × 10 ⁹ Ω·cm , and a dielectric constant of 21.65 at 1 MHz. The tangent value is 0.218.

Example 15

SiC powder having a mass percentage of 91% by mass, 17.36% by mass of boric acid, 33.6% by mass of urea and absolute ethanol were mixed and ball milled for 6 hours. The slurry was then placed in an oven at 80 ° C for 8 h, crushed and screened. A proper amount of the sample was placed in a mold for pre-compression molding, and the ammonia gas atmosphere was kept at 800 ° C for 3 hours in a tube furnace, and the heating rate was 3 ° C / min. The sample was then crushed and screened, followed by addition of 0.4% by mass of B ₄ C powder, 1% by mass of polyammonium methacrylate, 1.6% by mass of nano-carbon black, 1% by mass of polyvinyl butyral and none. The water was mixed with ethanol and ball milled for 4 h. The slurry was placed in a 50 ° C oven for 6 h, crushed and screened. An appropriate amount of the sample is placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 900 ° C for 1 hour for heat treatment at a heating rate of 2 ° C / min. Finally, it was sintered in an argon atmosphere at 2180 ° C for 1 hour in a high-temperature furnace at a heating rate of 3 ° C /min. After the sintering was completed, it was annealed at 1900 ° C for 6 h, and the cooling rate was 5 ° C / min. The resulting composite has a relative density of 98.5% TD, a thermal conductivity of 79.76 W·m ^-1 ·K ^-1 , a resistivity of 1.73 × 10 ¹¹ Ω·cm , a dielectric constant of 16.52 at 1 MHz, and a loss angle. The tangent value is 0.146.

Example 16

90% by mass of SiC powder, 19.84% by mass of boric acid, 38.4% by mass of urea and absolute ethanol were mixed and ball milled for 2 hours. The slurry was then placed in a 60 ° C oven for 16 h, crushed and screened. A suitable amount of sample is placed in a mold for pre-compression molding, and the temperature is maintained at 1000 ° C for 1 hour in a tube furnace, and the heating rate is 2 ° C / min. The sample was then crushed and screened, and then 0.6% by mass of B ₄ C powder, 1% by mass of polyethyleneimine, 2.4% by mass of phenolic resin, 0.5% by mass of polyvinyl butyral and absolute ethanol were added. Mix and ball mill for 6h. The slurry was placed in a 60 ° C oven for 6 h, crushed and sieved. A proper amount of the sample is placed in a mold for pre-compression molding, and then subjected to isostatic pressing, and heated in a vacuum resistance furnace to 800 ° C for 2 hours for heat treatment at a heating rate of 1 ° C / min. Finally, it was sintered in an argon atmosphere at 2170 ° C for 2 hours in a high temperature furnace at a heating rate of 5 ° C /min. After the sintering is completed, it is annealed at 2000 ° C for 6 h, and the cooling rate is 10 ° C / min. The resulting composite has a relative density of 98.1% TD, a thermal conductivity of 75.34 W·m ^-1 ·K ^-1 , a resistivity of 6.57 × 10 ¹² Ω·cm , and a dielectric constant of 15.17 at 1 MHz. The tangent value is 0.118.

Industrial Applicability: High Insulation Silicon Carbide Provided by the Invention / Boron nitride ceramic materials have high insulation properties, high resistivity, low dielectric constant and loss, and high thermal conductivity, which is especially suitable for heat dissipation applications in the field of electronic packaging. The method provided by the invention is simple and easy to control, low in cost, and suitable for scale production.

Claims

High-insulation silicon carbide/boron nitride ceramic material , characterized in that the ceramic material comprises silicon carbide, boron nitride uniformly distributed in the silicon carbide grain boundary by in-situ reaction, and boron carbide and carbon as sintering aids in the preparation of the ceramic material, Wherein the content of silicon carbide in the ceramic material is 90% by weight or more, the content of boron nitride is 0.5 to 10% by mass, the content of boron carbide is 0.2 to 2.0% by mass, and the content of carbon is 0.5 to 2.0% by mass.
The high-insulation silicon carbide/boron nitride ceramic material according to claim 1, wherein the boron nitride content is 1 to 8% by mass. The content of boron carbide is 0.4 to 1.0% by mass, and the content of carbon is 0.8 to 1.8% by mass.
The high-insulation silicon carbide/boron nitride ceramic material according to claim 1 or 2, wherein the ceramic material has a relative density of 90% TD or more and a thermal conductivity of 60 to 100 W·m -1 ·K -1 , DC resistance is 10 8 ~ 10 13 Ω · cm.
The high-insulation silicon carbide/boron nitride ceramic material according to claim 3, wherein the ceramic material has a relative density of 95% TD or more and a thermal conductivity of 80 to 100 W·m -1 · K -1 The DC resistivity is 10 10 to 10 12 Ω·cm.
The high-insulation silicon carbide/boron nitride ceramic material according to any one of claims 1 to 4, wherein the ceramic material is 1 MHz The dielectric constant is 15 to 100, and the loss tangent is 0.100 to 0.900.
High insulation silicon carbide according to claim 5 / A boron nitride ceramic material characterized in that the dielectric material has a dielectric constant of 15 to 30 at 1 MHz and a loss tangent of 0.100 to 0.300.
The high-insulation silicon carbide/boron nitride ceramic material according to any one of claims 1 to 6, wherein the boron nitride has an average particle diameter of 0.1 to 4.0 Micron.
A high insulating silicon carbide according to any one of claims 1 to 7 A method of boron nitride ceramic material, characterized in that the method comprises:

(a) Take (80 to 98) mass by weight % of silicon carbide powder, (0.7 to 11.2% by mass of silicon nitride powder, (0.6 to 5.2)% by mass of boron carbide and (1.5 to 3.5)% by mass of carbon source are added, (0 to 2.0) ) Quality % Dispersing agent, (0.2-10% by mass of binder) and solvent are ball milled, dried, pre-compressed and then isostatically pressed;

(b) The green body obtained in the step (a) is heated and debonded at 600 to 1000 ° C for 1 to 4 hours, and then at 1500 to 1800. °C, heat treatment in a nitrogen atmosphere for 4-8 hours to carry out in-situ reaction to form boron nitride;

(c) argon gas protection, sintering at 1900 ~ 2300 ° C for 1 to 4 hours;

(d) The ceramic material obtained in the step (c) is annealed at 1600 to 2100 ° C in an argon atmosphere for 0 to 16 hours.
Preparation of claims 1-7 A method of high-insulation silicon carbide/boron nitride ceramic material according to any one of the preceding claims, wherein the method comprises:

(a') silicon carbide powder, boric acid, urea according to mass ratio (90 ~ 98): (1.2 ~ 20): (2.5 ~ 60) for batching, ball milling mixing, drying, pre-forming;

(b') The green body obtained in the step (a') is heat-treated at 800 to 1000 ° C in a nitrogen atmosphere at 8 to 24 In-situ reaction in the form of boron nitride, or the green body obtained in step (a') is heat-treated at 700-1000 ° C in an ammonia atmosphere. In-situ reaction for 1 to 4 hours to form boron nitride;

(c') grinding the body obtained in the step (b') into a powder, and taking (98.9 to 97.2) by mass of the powder and (0.3 to 1.0) by mass % of boron carbide powder and (0.8~1.8)% by mass of carbon source are added, adding (0~2.0)% by mass of dispersant, (0.2~10)% by mass The binder and the solvent are ball milled, dried, pre-formed, and then isostatically pressed;

(d') is argon-protected and sintered at 1900~2300 °C for 1 to 4 hours;

(e') The ceramic material obtained in the step (d') is annealed at 1600 to 2100 ° C in an argon atmosphere for 0 to 16 hours.
The method of claim 9 wherein

The step (a') is: the silicon carbide powder, boric acid, and urea are compounded, ball milled, dried, and pre-formed according to a mass ratio (90 to 98): (1.2 to 20): (2.5 to 40);

The step (b') is: the green body obtained in the step (a') is heat-treated in an ammonia gas atmosphere at 700 to 1000 ° C for 1 to 4 hours to carry out in-situ reaction to form boron nitride.
The method according to any one of claims 8 to 10, wherein the carbon source is elemental carbon or cracks an organic substance capable of producing elemental carbon.