Rapid sintering method of high-performance aluminum nitride ceramic

Abstract

The invention discloses a high-performance aluminum nitride ceramic rapid sintering method, which belongs to the technical field of ceramic materials, and comprises the following steps: preparing a ceramic raw material according to a formula: uniformly mixing high-purity aluminum nitride powder, a sintering aid, an anti-hydrolysis agent and a solvent, and drying in a nitrogen atmosphere, the dosage ratio of the high-purity aluminum nitride powder to the sintering aid to the anti-hydrolysis agent is 1: (1%-3%): (0.5%-1.5%); the uniformly mixed aluminum nitride powder is subjected to hot pressed sintering for 10-60 min in a neutral or reducing atmosphere at the temperature of 1650-1850 DEG C and the pressure of 20-30 MPa, and the density of the aluminum nitride powder reaches 99% or above; and re-sintering the ceramic: sintering the primarily sintered aluminum nitride ceramic for 1-6 hours at the temperature of 1850-2000 DEG C and normal pressure in a reducing atmosphere. The prepared aluminum nitride ceramic not only has high heat-conducting property, but also is high in sintering efficiency, meanwhile, the problem that waste gas is generated in the degreasing process is avoided, and environmental protection is facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of ceramic materials, and in particular relates to a method for rapid sintering of high-performance aluminum nitride ceramics. Background Art

[0002] Aluminum nitride ceramic materials are known as the ideal substrate material for the new generation of high-power microelectronic devices due to their excellent material properties (high thermal conductivity, low dielectric constant, non-toxicity, superior insulation performance, high temperature and corrosion resistance, thermal expansion coefficient matching that of silicon, and good mechanical properties).

[0003] Conventional aluminum nitride ceramic sintering generally adopts one of normal pressure sintering or hot pressing sintering, among which normal pressure sintering has more stringent process requirements. A large amount of binder, plasticizer, sintering aid, etc. need to be added during the green body forming process. Generally, the normal pressure sintering method needs to add sintering aids of 5%-10% of the aluminum nitride powder, forming more second phases, and requires a higher sintering temperature and a longer holding time to prepare aluminum nitride ceramics with good thermal conductivity. Moreover, after the green body is formed, a degreasing process is generally required before sintering, and the temperature is slowly increased below 500°C (heating rate <1°C / min) to ensure that the green body does not crack during the degreasing process. During the high-temperature sintering process, a lower heating rate (heating rate <3°C / min) is also required to ensure that no major defects are generated during the densification process of aluminum nitride ceramics, which will cause problems such as high energy consumption and low production efficiency. In addition, after adding a large amount of binders and plasticizers, not only will a large amount of carbon residues be left after degreasing, affecting the final performance of aluminum nitride ceramics, but also waste gas will be generated during the degreasing process, causing environmental pollution. Hot pressing sintering does not require the addition of a large amount of binders, plasticizers, and sintering aids. Not only does it only require the addition of a small amount of sintering aids, but it can also be sintered quickly at an extremely fast heating rate, so that aluminum nitride ceramics can quickly achieve densification and have good mechanical properties. However, hot pressing sintering has the disadvantage that impurities such as the second phase of aluminum nitride ceramics are not easy to volatilize, and it is not easy to prepare aluminum nitride ceramics with high thermal conductivity.

[0004] Therefore, both sintering methods have their defects. In the prior art, in order to obtain aluminum nitride ceramic materials, corresponding improvements are usually made in the sintering methods used to overcome their defects. Summary of the invention

[0005] The purpose of the present invention is to provide a method for rapid sintering of high-performance aluminum nitride ceramics to solve the problem that the aluminum nitride ceramics produced by the existing preparation process have low performance or low production efficiency.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A method for rapid sintering of high-performance aluminum nitride ceramics comprises the following steps:

[0008] Step S1, preparing ceramic raw materials according to the formula: mixing high-purity aluminum nitride powder, sintering aid, anti-hydrolysis agent and solvent evenly, and drying under nitrogen atmosphere, wherein the dosage ratio of high-purity aluminum nitride powder, sintering aid and anti-hydrolysis agent is 1:1%-3%:0.5%-1.5%;

[0009] Step S2, ceramic initial firing: hot-pressing and sintering the uniformly mixed aluminum nitride powder in a neutral or reducing atmosphere at 1650-1850° C. and a pressure of 20-30 MPa for 10-60 min to achieve a density of more than 99%;

[0010] Step S3, ceramic re-firing: sintering the aluminum nitride ceramic after the initial firing at 1850-2000° C. and normal pressure for 1-6 hours in a reducing atmosphere.

[0011] The further improvement of the technical solution of the present invention is that: the high-purity aluminum nitride powder has an O content of less than 0.7%, a purity of more than 99%, a particle size of less than 2 μm, and a specific surface area of ​​more than 2.3 m 2 / g.

[0012] A further improvement of the technical solution of the present invention is that the sintering aid includes at least one of yttrium oxide, yttrium fluoride, dysprosium oxide, calcium oxide and calcium fluoride, with a purity of more than 99.9% and a particle size of less than 500nm.

[0013] A further improvement of the technical solution of the present invention is that the anti-hydrolysis agent includes at least one of oleic acid, stearic acid, Tween-80, phosphoric acid, aluminum dihydrogen phosphate, and magnesium dihydrogen phosphate.

[0014] The further improvement of the technical solution of the present invention is that the specific steps of the ceramic initial firing are: filling the mixed uniform powder into a graphite high-temperature hot pressing furnace for sintering, sintering at a temperature of 1650-1850°C in a nitrogen atmosphere or a reducing atmosphere, sintering for 10-60 minutes, so that its density reaches more than 99%.

[0015] A further improvement of the technical solution of the present invention is that the specific process of sintering is: heating to 1500°C at a rate of 25°C / min, starting to apply pressure, heating to 1650-1850°C at a rate of 20°C / min, at which time the pressure applied is 20-30Mpa, keeping the temperature and pressure for 10-60 minutes, and then naturally cooling and reducing the pressure, and flowing nitrogen during the sintering process.

[0016] A further improvement of the technical solution of the present invention is that the specific steps of the ceramic re-firing are: placing the aluminum nitride ceramic after the initial firing into a graphite high-temperature furnace for sintering, the sintering temperature is 1850-2000°C in a nitrogen atmosphere or a reducing atmosphere, and the sintering time is 1-6 hours.

[0017] The further improvement of the technical solution of the present invention is that the specific process of ceramic re-sintering is: heating to 1500°C at a rate of 25°C / min, heating to 1850-2000°C at a rate of 20°C / min, keeping warm for 1-6 hours and then cooling naturally, and flowing nitrogen during the sintering process.

[0018] A high-performance aluminum nitride ceramic is prepared by using the above-mentioned high-performance aluminum nitride ceramic rapid sintering method. The crystal phase of the high-performance aluminum nitride ceramic is a single AlN phase without other grain boundary phases.

[0019] A further improvement of the technical solution of the present invention is that the thermal conductivity of the high performance aluminum nitride ceramic is

[0020] ≥240W / mk, flexural strength ≥350Mpa, 3.25<bulk density<3.28g / cm 3 .

[0021] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is:

[0022] The present invention overcomes the shortcomings of conventional hot pressing sintering and normal pressure sintering, and makes ingenious improvements to the sintering method. The initial sintering adopts hot pressing sintering to quickly densify the aluminum nitride ceramic, and the temperature can be quickly raised, so that the sintering efficiency is greatly improved. In the entire sintering process of the aluminum nitride ceramic, only a small amount of sintering aid needs to be added, and no binder or plasticizer needs to be added, which is beneficial to reducing the impurity content in the finished product and improving the sintering performance of the aluminum nitride ceramic. The debinding process can also be eliminated, which not only improves the sintering efficiency, but also eliminates waste gas emissions during the debinding process, and is environmentally friendly. The re-firing adopts normal pressure sintering heat treatment, which can completely remove the second phase impurities generated by the reaction of the sintering aid and alumina during the initial sintering of the aluminum nitride ceramic. The prepared aluminum nitride ceramic can reach a single AlN phase and has no internal defects. Therefore, high-performance aluminum nitride ceramics can be prepared.

[0023] The present invention adopts hot pressing sintering in the initial firing, and does not need dry pressing or cold isostatic pressing to prepare the green blank, thus saving operation steps. The temperature can be quickly raised during the sintering process, so that the ceramic can quickly reach densification, greatly improving the sintering efficiency, and there is no need to add a large amount of sintering aids during the sintering process, reducing the generation of the second phase during the sintering process, and providing a basis for completely removing the second phase by normal pressure re-firing. In addition, there is no need to add green embryo forming materials such as binders and plasticizers, so there is no need for degreasing, which not only saves degreasing time, but also avoids the problem of generating waste gas during the degreasing process, which is beneficial to environmental protection; normal pressure re-firing heat treatment can help to discharge lattice oxygen and volatilize the residual second phase at the grain boundary, so that the prepared aluminum nitride ceramics not only have high thermal conductivity, but also have fast sintering efficiency and the characteristics of efficient production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1A scanning electron microscope image of a cross section of the aluminum nitride ceramic prepared in Example 1;

[0025] Figure 2 This is the XRD scan of the aluminum nitride ceramic prepared in Example 1;

[0026] Figure 3 This is a scanning electron microscope image of the cross section of the aluminum nitride ceramic prepared in Comparative Example 1;

[0027] Figure 4 This is a scanning electron microscope image of the cross section of the aluminum nitride ceramic prepared in Comparative Example 2. DETAILED DESCRIPTION

[0028] For ease of understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0029] The aluminum nitride powder and sintering aid used in the following examples are both high-purity ultrafine powders, wherein the aluminum nitride powder has a particle size of <2 μm, a purity of ≥99%, and an oxygen content of <0.7%; the sintering aid has a particle size of <500 nm and a purity of >99.9%.

[0030] Example 1

[0031] (1) Raw material mixing

[0032] Aluminum nitride powder, yttrium oxide powder, calcium fluoride powder, oleic acid, solvent, and ball milling medium were placed in a rolling ball mill for 6 hours. The milled slurry was then dried at 80° C. in a nitrogen atmosphere.

[0033] Based on 100% of the mass of aluminum nitride powder, the added amounts of yttrium oxide powder, calcium fluoride powder, oleic acid, solvent, and ball milling medium are 2%, 0.5%, 0.3%, 100%, and 500%, respectively. The solvent is anhydrous ethanol, and the ball milling medium is aluminum oxide balls.

[0034] (2) Hot pressing and initial firing

[0035] The dried mixed powder was placed in a graphite hot press furnace for hot pressing and sintering to obtain a primary fired product with a density of 3.29 g / cm 3 .

[0036] The specific process of sintering is: heating to 1500℃ at a rate of 25℃ / min, at which time pressure is applied, heating to 1800℃ at a rate of 20℃ / min, at which time the pressure applied is 20Mpa, and then naturally cooling and reducing pressure after keeping the temperature and pressure for 60 minutes. Nitrogen is passed during the sintering process. The total time for the initial sintering is 135 minutes.

[0037] (3) Normal pressure re-firing

[0038] The initially fired product is placed in a graphite sintering furnace for re-firing at normal pressure to obtain a high-performance aluminum nitride ceramic product.

[0039] The specific process of sintering is: heating to 1500℃ at a rate of 25℃ / min, heating to 1900℃ at a rate of 20℃ / min, keeping warm for 180min and then cooling naturally. Nitrogen is flowed during sintering. The total time for re-firing is 260min, and the total time for this sintering is 395min.

[0040] The aluminum nitride ceramics in this example were characterized by scanning electron microscopy and XRD. Figure 1 , Figure 2 ,from Figure 1 , Figure 2 It can be seen that the high-strength and high-thermal-conductivity aluminum nitride ceramic prepared in this embodiment only contains aluminum nitride phase.

[0041] The aluminum nitride ceramics prepared in this embodiment were tested and the properties were as follows: the volume density was 3.27 g / cm 3 , thermal conductivity is 245W / m·K, and flexural strength is 380MPa.

[0042] Example 2

[0043] (1) Raw material mixing

[0044] Aluminum nitride powder, yttrium oxide powder, calcium oxide powder, stearic acid, Tween 80, solvent, and ball milling medium were placed in a rolling ball mill for 6 hours. The milled slurry was then dried at 110° C. under a nitrogen atmosphere.

[0045] Based on 100% of the mass of aluminum nitride powder, the added amounts of yttrium oxide powder, calcium oxide powder, stearic acid, Tween 80, solvent, and ball milling medium are 2%, 1%, 1%, 0.5%, 110%, and 500%, respectively. The solvent is anhydrous ethanol, and the ball milling medium is aluminum oxide balls.

[0046] (2) Hot pressing and initial firing

[0047] The dried mixed powder was placed in a graphite hot press furnace for hot pressing and sintering to obtain a primary fired product with a density of 3.28 g / cm 3 .

[0048] The specific process of sintering is: heating to 1500℃ at a rate of 25℃ / min, then starting to apply pressure, heating to 1750℃ at a rate of 20℃ / min, then applying 25Mpa of pressure, keeping the temperature and pressure for 30min, then naturally cooling and reducing the pressure. Flowing nitrogen was passed during the sintering process. The total time for the initial firing was 102.5min.

[0049] (3) Normal pressure re-firing

[0050] The initially fired product is placed in a graphite sintering furnace for re-firing at normal pressure to obtain a high-performance aluminum nitride ceramic product.

[0051] The specific process of sintering is: heating to 1500°C at a rate of 25°C / min, heating to 1950°C at a rate of 20°C / min, keeping warm for 120 minutes and then cooling naturally. Nitrogen is passed during sintering. The total time for re-firing is 202.5 minutes, and the total time for this sintering is 305 minutes. The high-strength and high-thermal-conductivity aluminum nitride ceramic substrate prepared in this embodiment contains only aluminum nitride phase.

[0052] The aluminum nitride ceramics prepared in this embodiment were tested and the properties were as follows: the volume density was 3.26 g / cm 3 , thermal conductivity is 250W / m·K, and flexural strength is 363MPa.

[0053] Example 3

[0054] (1) Raw material mixing

[0055] Aluminum nitride powder, yttrium oxide powder, yttrium fluoride powder, phosphoric acid, solvent, and ball milling medium are placed in a rolling ball mill for 6 hours. The milled slurry is then dried at 90° C. under a nitrogen atmosphere.

[0056] Based on 100% of the mass of aluminum nitride powder, the added amounts of yttrium oxide powder, yttrium fluoride powder, phosphoric acid, solvent and ball milling medium are 2%, 1%, 1%, 120% and 500% respectively. The solvent is anhydrous ethanol and the ball milling medium is aluminum oxide ball.

[0057] (2) Hot pressing and initial firing

[0058] The dried mixed powder was placed in a graphite hot press furnace for hot pressing and sintering to obtain a primary fired product with a density of 3.30 g / cm 3 .

[0059] The specific process of sintering is: heating to 1500℃ at a rate of 25℃ / min, then starting to apply pressure, heating to 1800℃ at a rate of 20℃ / min, then applying 25Mpa pressure, keeping temperature and pressure for 60min, then naturally cooling and reducing pressure. Flowing nitrogen during sintering. The total time for initial sintering is 135min.

[0060] (3) Normal pressure re-firing

[0061] The initially fired product is placed in a graphite sintering furnace for re-firing at normal pressure to obtain a high-performance aluminum nitride ceramic product.

[0062] The specific process of sintering is: heating to 1500℃ at a rate of 25℃ / min, heating to 2000℃ at a rate of 20℃ / min, keeping the temperature for 60min and then cooling naturally. Nitrogen is flowed during the sintering process. The total time for re-firing is 145min, and the total time for this sintering is 280min.

[0063] The aluminum nitride ceramics prepared in this embodiment were tested and the properties were as follows: the volume density was 3.27 g / cm 3 , thermal conductivity is 261W / m·K, and flexural strength is 351MPa.

[0064] Comparative Example 1

[0065] (1) Raw material mixing

[0066] Aluminum nitride powder, yttrium oxide powder, oleic acid, PVB, DBP, solvent, and ball milling medium are placed in a rolling ball mill for 10 hours to obtain a tape casting slurry.

[0067] Based on 100% of the mass of aluminum nitride powder, the added amounts of yttrium oxide powder, oleic acid, PVB, DBP, solvent, and ball milling medium are 8%, 0.3%, 10%, 5%, 100%, and 500%, respectively. The solvent is a 1:1 mixed solution of ethanol / n-butanol, and the ball milling medium is aluminum oxide balls.

[0068] (2) Green preparation

[0069] The slurry is formed by tape casting, the green body thickness is 0.5mm, and then isostatically pressed at a pressure of 10-15MPa and a temperature of 70°C.

[0070] (3) Degreasing

[0071] Degreasing was performed in a nitrogen atmosphere at a degreasing temperature of 500°C.

[0072] The specific process of degreasing is: heating to 500°C at a rate of 1°C / min and keeping the temperature for 60min. The total degreasing time is 560min.

[0073] (4) Sintering

[0074] The degreased green body is placed in a graphite high temperature furnace for normal pressure sintering to obtain an aluminum nitride ceramic product.

[0075] The specific process of sintering is: heating to 1200℃ at a rate of 10℃ / min, heating to 1500℃ at a rate of 5℃ / min, heating to 1900℃ at a rate of 2℃ / min, keeping the temperature for 360min and then cooling naturally. Nitrogen is flowed during the sintering process. The total sintering time is 740min, and the total time for degreasing and sintering is 1300min.

[0076] The aluminum nitride ceramics in this comparative example were characterized by scanning electron microscopy. Figure 3 ,from Figure 3 It can be seen that the aluminum nitride ceramic prepared in this comparative example contains not only the aluminum nitride phase but also a second phase at the grain boundary.

[0077] The aluminum nitride ceramics prepared in this comparative example were tested and the properties were as follows: the volume density was 3.31 g / cm 3 , thermal conductivity is 238W / m·K, and flexural strength is 330MPa.

[0078] Comparative Example 2

[0079] (1) Raw material mixing

[0080] Aluminum nitride powder, yttrium oxide powder, oleic acid, solvent and ball milling medium were placed in a rolling ball mill for 6 hours. The milled slurry was then dried at 100° C. under a nitrogen atmosphere.

[0081] Based on 100% of the mass of aluminum nitride powder, the added amounts of yttrium oxide powder, oleic acid, solvent and ball milling medium are 3%, 0.5%, 120% and 500% respectively. The solvent is anhydrous ethanol and the ball milling medium is aluminum oxide ball.

[0082] (2) Hot pressing sintering

[0083] The dried mixed powder is placed in a graphite hot pressing furnace for hot pressing and sintering to obtain an aluminum nitride ceramic product.

[0084] The specific process of sintering is: heating to 1500℃ at a rate of 25℃ / min, then starting to apply pressure, heating to 1800℃ at a rate of 20℃ / min, then applying 25Mpa pressure, keeping the temperature and pressure for 60min, then naturally cooling and reducing the pressure. Nitrogen is passed during the sintering process. The total time for hot pressing sintering is 135min.

[0085] The aluminum nitride ceramics in this comparative example were characterized by scanning electron microscopy. Figure 4 ,from Figure 4 It can be seen that the aluminum nitride ceramic prepared in this comparative example contains not only the aluminum nitride phase but also a second phase at the grain boundary.

[0086] The aluminum nitride ceramics prepared in this comparative example were tested and the properties were as follows: the volume density was 3.32 g / cm 3 , thermal conductivity is 165W / m·K, and flexural strength is 403MPa.

[0087] The thermal conductivity, flexural strength and total sintering time of the aluminum nitride ceramics in Examples 1-3 and Comparative Examples 1-2 were compared and summarized. The results are shown in Table 1:

[0088] Table 1 Thermal conductivity, flexural strength and total sintering time of aluminum nitride ceramics

[0089] Thermal conductivity Flexural strength Total sintering time Example 1 245W / mK 380Mpa 395min Example 2 250W / mK 363Mpa 305min Example 3 261W / mK 351Mpa 280min Comparative Example 1 238W / mK 330Mpa 1300min Comparative Example 2 165W / mK 403Mpa 135min

[0090] Note: In the above tests, the flexural strength was tested using a Shimadzu flexural strength tester, and the thermal conductivity was tested using a Hot Disk TPS2500S thermal conductivity tester.

[0091] It can be seen from Table 1 that compared with Comparative Example 1 (conventional pressureless sintering), the sintering time of the sintering method of the present invention can be shortened by more than 4 times, and the thermal conductivity is also higher than that of the pressureless sintering sample; compared with Comparative Example 2 (conventional hot pressing sintering), the sintering time of the sintering method of the present invention is longer than that of the conventional hot pressing sintering, but the thermal conductivity is much higher than that of the conventional hot pressing sintering sample.

[0092] The above records are only embodiments of the present invention. Any modification or change made by a person familiar with the present technology using the present invention shall fall within the patent scope claimed by the present invention and shall not be limited to those disclosed in the embodiments.

Claims

1. A method for rapid sintering of high-performance aluminum nitride ceramics, characterized in that The following steps are involved: Step S1, preparing ceramic raw materials according to the formula: mixing high-purity aluminum nitride powder, sintering aid, anti-hydrolysis agent and solvent evenly, and drying under nitrogen atmosphere, wherein the dosage ratio of high-purity aluminum nitride powder, sintering aid and anti-hydrolysis agent is 1:1%-3%:0.5%-1.5%; Step S2, ceramic initial firing: hot-pressing and sintering the uniformly mixed aluminum nitride powder in a neutral or reducing atmosphere at 1650-1850° C. and a pressure of 20-30 MPa for 10-60 min to achieve a density of more than 99%; Step S3, ceramic re-firing: sintering the aluminum nitride ceramic after the initial firing at 1850-2000° C. and normal pressure for 1-6 hours in a reducing atmosphere.

2. A high performance aluminum nitride ceramic rapid sintering method according to claim 1, characterized in that: The high-purity aluminum nitride powder has an O content of less than 0.7%, a purity of more than 99%, a particle size of less than 2 μm, and a specific surface area of ​​more than 2.3 m 2 / g.

3. The method for rapid sintering of high-performance aluminum nitride ceramics according to claim 1, characterized in that: The sintering aid comprises at least one of yttrium oxide, yttrium fluoride, dysprosium oxide, calcium oxide and calcium fluoride, with a purity of more than 99.9% and a particle size of less than 500nm.

4. The method for rapid sintering of high-performance aluminum nitride ceramics according to claim 1, characterized in that: The anti-hydrolysis agent includes at least one of oleic acid, stearic acid, Tween-80, phosphoric acid, aluminum dihydrogen phosphate and magnesium dihydrogen phosphate.

5. The method for rapid sintering of high performance aluminum nitride ceramics according to claim 1, characterized in that: The specific steps of the ceramic initial firing are: filling the mixed uniform powder into a graphite high-temperature hot pressing furnace for sintering, sintering at a temperature of 1650-1850°C in a nitrogen atmosphere or a reducing atmosphere, sintering for 10-60 minutes, so that its density reaches more than 99%.

6. A high performance aluminum nitride ceramic rapid sintering method according to claim 5, characterized in that: The specific process of sintering is: heat up to 1500℃ at a rate of 25℃ / min, start to apply pressure, heat up to 1650-1850℃ at a rate of 20℃ / min, at which time the pressure applied is 20-30Mpa, keep warm and maintain pressure for 10-60min, then naturally cool down and reduce pressure, and flow nitrogen during sintering.

7. The method for rapid sintering of high performance aluminum nitride ceramics according to claim 1, characterized in that: The specific steps of the ceramic re-firing are: placing the aluminum nitride ceramic after the initial firing into a graphite high-temperature furnace for sintering, sintering at a temperature of 1850-2000° C. in a nitrogen atmosphere or a reducing atmosphere, and sintering for 1-6 hours.

8. A high performance aluminum nitride ceramic rapid sintering method according to claim 7, characterized in that: The specific process of ceramic re-sintering is: heating to 1500°C at a rate of 25°C / min, heating to 1850-2000°C at a rate of 20°C / min, keeping warm for 1-6 hours and then cooling naturally, and flowing nitrogen during the sintering process.

9. A high performance aluminum nitride ceramic, characterized in that: The high-performance aluminum nitride ceramic is prepared by using a rapid sintering method according to any one of claims 1 to 8, wherein the crystal phase of the high-performance aluminum nitride ceramic is a single AlN phase without other grain boundary phases.

10. The high performance aluminum nitride ceramic according to claim 9, characterized in that: The high-performance aluminum nitride ceramic has a thermal conductivity of ≥240W / mk, a flexural strength of ≥350Mpa, and a volume density of 3.25<3.28g / cm 3 .

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