Dynamic sintering method for nitride ceramic substrates

Abstract

The present invention provides a dynamic sintering method for nitride ceramic substrate, which belongs to the technical field of ceramic materials. By utilizing the difference in shrinkage start temperature and shrinkage rate between the support block and the nitride ceramic substrate, the shrinkage start temperature of the support block is controlled to be lower or higher than the shrinkage start temperature of the nitride ceramic substrate, and the linear shrinkage rate in the height direction is controlled to be higher than the linear shrinkage rate of the nitride ceramic substrate, so as to realize the dynamic process from non-contact to contact between the pressure plate and the substrate during the sintering process, thereby preventing the substrate from being deformed or cracked during sintering.

Description

Cross-reference to Related Applications

[0001] This application claims the priority of a Chinese patent application with the application number 202210349584.8 and the invention title of "Dynamic Sintering Method of Nitride Ceramic Substrate" filed with the China National Intellectual Property Administration on April 2, 2022, and all its contents are incorporated herein by reference.

Technical Field

[0002] The present invention relates to the technical field of ceramic materials, and particularly to a dynamic sintering method of nitride ceramic substrates.

Background Art

[0003] Ceramic substrates are important components that play roles in load-bearing, heat dissipation, and insulation of power semiconductor modules. Since they are affected by large thermal stresses and mechanical stresses during operation, high thermal conductivity and excellent mechanical properties are required. Nitride ceramic substrates (aluminum nitride, silicon nitride) are optimal materials for ceramic substrates for high-power components due to their high thermal conductivity.

[0004] Nitrides such as silicon nitride and aluminum nitride are covalent compounds, which are difficult to sinter. In order to achieve sintering densification, it is necessary to add a certain amount of sintering aids. In addition, the sintering shrinkage rate is large and it is easy to deform, which greatly increases the difficulty of manufacturing nitride substrates. In order to reduce the shrinkage deformation during sintering of nitride substrates, usually, in order to prevent the deformation of the substrate during the sintering process, a "pressure sintering" method of pressing a flat plate with a certain weight on the substrate is used. However, the presence of the pressure plate inhibits the shrinkage of the substrate to a certain extent and may even cause cracks in the substrate during sintering shrinkage. Therefore, further study of a sintering method suitable for nitride ceramic substrates is necessary.

Summary of the Invention

[0005] The object of the present invention is to provide a dynamic sintering method for a nitride ceramic substrate that can realize the dynamic process from non-contact to contact between a pressure plate and the substrate during the sintering process, and avoid deformation and cracking of the nitride ceramic substrate during sintering.

Means for Solving the Problems

[0006] In order to achieve the above object of the present invention, the present invention provides the following technical solutions. The present invention provides a dynamic sintering method for a nitride ceramic substrate, placing the nitride ceramic substrate non-contact between n support blocks with the same height, placing a pressure plate above the n support blocks with the same height, where n≥2, the pressure plate and the nitride ceramic substrate are arranged in parallel, the distance between the pressure plate and the nitride ceramic substrate is 0.01-1 mm, the length of the pressure plate>the length of the nitride ceramic substrate, and the width of the pressure plate>the width of the nitride ceramic substrate; adjusting the composition of the sintering aid and / or the molding pressure of the support block so that the shrinkage start temperature of the support block is lower or higher than that of the nitride ceramic substrate, and the linear shrinkage rate of the support block in the height direction is higher than that of the nitride ceramic substrate in the height direction, performing sintering to obtain a sintered nitride ceramic substrate, and the sintering process includes heating to 1700-2000 °C at a heating rate of 0.1-10 °C / min and holding for 1-12 hours.

[0007] Preferably, the nitride ceramic substrate is a silicon nitride substrate or an aluminum nitride substrate, and the molding method of the nitride ceramic substrate is tape casting molding, dry pressing molding, gel casting molding or tape winding molding.

[0008] Preferably, the thickness of the nitride ceramic substrate is 0.2-2.0 mm, the length is 300 mm or less, and the width is 300 mm or less.

[0009] Preferably, the number of the nitride ceramic substrates is 1 or more. When the number of the nitride ceramic substrates is greater than 1, the nitride ceramic substrates are stacked and arranged, the number of stacking layers is 30 or less, and adjacent nitride ceramic substrates are separated by a boron nitride separation powder layer. The thickness of the boron nitride separation powder in different layers is independently 20 to 300 μm.

[0010] Preferably, the material of the pressure plate is boron nitride, silicon nitride, aluminum nitride or graphite.

[0011] Preferably, the calculation formula of the weight of the pressure plate is as follows:

[0012] [Equation 1] W = P×S / 9.8-(N - 1)×W1

[0013] Here, P is the pressure received by the lowermost nitride ceramic substrate, P = 30 to 500 Pa, S is the force-receiving area of the nitride ceramic substrate (m 2 ²), N is the number of stacking layers of the nitride ceramic substrates, N = 1 to 30, and W1 is the weight (kg) of a single nitride ceramic substrate.

[0014] Preferably, the material of the support block is the same as the material of the nitride substrate. The molding method of the support block is dry pressing molding or cold isostatic pressing molding. The upper surface and the lower surface of the support block are parallel, and the cross-sectional area of the support block is 30 mm 2 or more.

[0015] Preferably, the shrinkage start temperature of the support block is 1300 to 1700 °C, and the linear shrinkage rate in the height direction of the support block is 16 to 24%.

[0016] Preferably, the difference value between the shrinkage start temperature of the support block and the shrinkage start temperature of the nitride ceramic substrate is 30 to 100 °C, and the difference value between the linear shrinkage rate in the height direction of the support block and the linear shrinkage rate in the height direction of the nitride ceramic substrate is 0.2 to 6%.

Advantages of the Invention

[0017] The present invention provides a dynamic sintering method for a nitride ceramic substrate. By utilizing the differences in the shrinkage start temperature and shrinkage rate between the support block and the nitride ceramic substrate, the shrinkage start temperature of the support block is made lower or higher than that of the nitride ceramic substrate, and the linear shrinkage rate in the height direction is controlled to be higher than that of the nitride ceramic substrate, thereby realizing a dynamic process from non-contact to contact between the pressure plate and the substrate during the sintering process. This can prevent cracks in the substrate during sintering, reduce deformation during sintering, and suppress the warpage degree to less than 1.0 μm / mm.

Brief Description of the Drawings

[0018]

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Modes for Carrying Out the Invention

[0019] The present invention provides a dynamic sintering method for a nitride ceramic substrate. Place the nitride ceramic substrate non - contact between n support blocks of the same height, place the pressure plate above the n support blocks of the same height, where n≥2, the pressure plate and the nitride ceramic substrate are arranged in parallel, the distance between the pressure plate and the nitride ceramic substrate is 0.01 - 1 mm, the length of the pressure plate > the length of the nitride ceramic substrate, and the width of the pressure plate > the width of the nitride ceramic substrate; Adjust the composition of the sintering aid and / or the molding pressure of the support block so that the shrinkage start temperature of the support block is lower or higher than that of the nitride ceramic substrate, and the linear shrinkage rate of the support block in the height direction is higher than that of the nitride ceramic substrate in the height direction, then perform sintering to obtain the sintered nitride ceramic substrate. The process of sintering includes heating to 1700 - 2000 °C at a heating rate of 0.1 - 10 °C / min and holding for 1 - 12 hours.

[0020] In the present invention, the necessary raw materials and reagents are commercially available products well - known to those skilled in the art unless otherwise specified.

[0021] In the present invention, the nitride ceramic substrate is placed non - contact between n support blocks of the same height, where n≥2. In the present invention, the nitride ceramic substrate is preferably a silicon nitride substrate or an aluminum nitride substrate, and the forming method of the nitride ceramic substrate is preferably tape casting, dry pressing, gel casting or tape rolling. The present invention has no particular limitation on the specific manufacturing method of the nitride ceramic substrate, and it may be manufactured according to a process well - known in the art.

[0022] In the present invention, the thickness of the nitride ceramic substrate is preferably 0.2 - 2.0 mm, more preferably 0.5 - 1.5 mm, the length is preferably ≤300 mm, more preferably 150 mm, and the width is preferably ≤300 mm, more preferably 150 mm.

[0023] In the present invention, the number of the nitride ceramic substrates is 1 or more. When the number of the nitride ceramic substrates is 1 or more, the nitride ceramic substrates are stacked and arranged. The number of stacked nitride ceramic substrates is preferably 30 or less, more preferably 5 to 20. The adjacent nitride ceramic substrates are separated by a boron nitride separation powder layer. The thickness of the boron nitride separation powder in different layers is preferably independently 20 to 300 μm, more preferably 50 to 200 μm.

[0024] In the present invention, the nitride ceramic substrate is disposed non - contactingly between n support blocks having the same height. The material of the support block is preferably the same as that of the nitride substrate. The molding method of the support block is preferably dry pressing molding and / or cold isostatic pressing molding. The upper surface and the lower surface of the support block are parallel, and the cross - sectional area of the support block is 30 mm 2 or more. The present invention does not impose special restrictions on the shape and manufacturing process of the support block, and it may be manufactured according to the processes well - known in the art and adjusted according to actual needs. In the embodiment of the present invention, the size of the support block is 10 mm×10 mm×5.2 mm or 10 mm×10 mm×7.8 mm. The composition of the sintering aid of the support block is 5% yttrium oxide (mass percentage relative to the total mass of silicon nitride and the sintering aid) and 5% alumina (mass percentage relative to the total mass of silicon nitride and the sintering aid), and the molding pressure is 50 MPa. Alternatively, the material of the support block is aluminum nitride, the size is 20 mm×20 mm×1.52 mm, the composition of the sintering aid of the support block is 10% neodymium oxide (mass percentage relative to the total mass of aluminum nitride and the sintering aid), and the molding pressure is 20 MPa.

[0025] In the present invention, the shrinkage start temperature of the support block is preferably 1300 to 1700 °C, more preferably 1450 to 1600 °C, and the linear shrinkage rate in the height direction of the support block is preferably 16 to 24%.

[0026] The present invention arranges a pressure plate above the n support blocks with the same height. In the present invention, the pressure plate and the nitride ceramic substrate are arranged in parallel, and the distance between the pressure plate and the nitride ceramic substrate is 0.01 - 1 mm, preferably 0.02 - 0.03 mm. The length of the pressure plate > the length of the nitride ceramic substrate, the width of the pressure plate > the width of the nitride ceramic substrate, and the difference between the length of the pressure plate and the length of the nitride ceramic substrate is preferably 10 mm or more, and the difference between the width of the pressure plate and the width of the nitride ceramic substrate is preferably 10 mm or more.

[0027] In the present invention, the material of the pressure plate is preferably boron nitride, silicon nitride, aluminum nitride or graphite.

[0028] In the present invention, the calculation formula for the weight of the pressure plate is as follows:

[0029] [Equation 2] W = P×S / 9.8 - (N - 1)×W1

[0030] Here, P is the pressure received by the lowermost nitride ceramic substrate, P = 30 - 500 Pa, S is the force-receiving area of the nitride ceramic substrate (m 2 )), N is the number of stacked nitride ceramic substrates, N = 1 - 30, and W1 is the weight (kg) of a single nitride ceramic substrate.

[0031] The present invention adjusts the composition of the sintering aid and / or the molding pressure of the support block so that the shrinkage start temperature of the support block is lower or higher than the shrinkage start temperature of the nitride ceramic substrate, and the linear shrinkage rate of the support block in the height direction is higher than the linear shrinkage rate of the nitride ceramic substrate in the height direction, and then performs sintering to obtain a sintered nitride ceramic substrate. The process of the sintering is to raise the temperature to 1700-2000 °C at a heating rate of 0.1-10 °C / min and hold for 1-12 hours. In the present invention, the heating rate of the sintering is preferably 1-5 °C / min, preferably raise the temperature to 1850 °C-1900 °C, and the heat preservation time is preferably 3-6 hours. The present invention preferably adjusts the shrinkage start temperature and the linear shrinkage rate in the height direction of the support block by measuring the shrinkage curves of the support block at different pressures or by measuring the shrinkage curves of the support block in different compositions of the sintering aid. In the present invention, the temperature at which the linear shrinkage rate in the height direction becomes 5% is defined as the shrinkage start temperature. The present invention preferably measures the sintering shrinkage curves of the support block and the nitride ceramic substrate using a high-temperature dilatometer.

[0032] In the present invention, the difference value between the shrinkage start temperature of the support block and the shrinkage start temperature of the nitride ceramic substrate is preferably 30-100 °C, more preferably 50-80 °C, and the difference value between the linear shrinkage rate of the support block in the height direction and the linear shrinkage rate of the nitride ceramic substrate in the height direction is preferably 0.2-6%, more preferably 2.1-3.3%.

[0033] As one aspect of the present invention, as shown in Figure 1, in the initial stage of sintering, the pressure plate and the nitride ceramic substrate are in a non-contact state. In the intermediate stage of sintering, since the shrinkage start temperature of the support block is lower than the shrinkage start temperature of the nitride ceramic substrate and the shrinkage start time is earlier than that of the nitride ceramic substrate, the weight of the pressure plate gradually acts on the nitride ceramic substrate (b in Figure 1), playing a role in preventing the deformation of the nitride ceramic substrate due to intense shrinkage. At this time, the number of pores decreases, the strength of the base material is greatly improved compared with that immediately after the adhesive is extruded, and cracks will not occur due to the weight of the bearing plate.

[0034] As another aspect of the present invention, as shown in FIG. 2, in the initial stage of sintering, the pressure plate and the nitride ceramic substrate are in a non-contact state. In the intermediate stage of sintering, the shrinkage start temperature of the support block is higher than that of the nitride ceramic substrate, that is, the shrinkage start time is later than that of the nitride ceramic substrate. Therefore, when the nitride ceramic substrate starts to shrink and deform, it contacts the pressure plate (b in FIG. 2), and the deformation is restricted, but basically it does not affect the shrinkage of the substrate. Since the linear shrinkage rate of the support block in the height direction is larger than that of the nitride ceramic substrate, the weight of the pressure plate gradually acts on the substrate (c in FIG. 2), playing a role in high-temperature smoothing. The present invention has no special definition for the initial stage and the middle stage of the sintering, and it may be understood according to the definition well-known in the technical field.

[0035] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts are included within the protection scope of the present invention.

[0036] Example 1 As arranged as shown in Fig. 1, the size of the silicon nitride substrate is 150 mm × 150 mm × 0.5 mm, the weight of a single silicon nitride substrate is 0.023 kg, the composition of the sintering aid for the silicon nitride substrate is 5% erbium oxide (mass percentage based on the total mass of silicon nitride and sintering aid), 3% magnesium oxide (mass percentage based on the total mass of silicon nitride and sintering aid), the forming method is tape casting, the number of layers of the silicon nitride substrate is 10, the thickness of the boron nitride separation powder in each layer is 50 μm, the material of the pressure plate is boron nitride, the weight is 250 g, the distance between the pressure plate and the nitride ceramic substrate is 0.02 mm, the length and width of the pressure plate are both 20 mm larger than the substrate, the pressure received by the lowermost silicon nitride substrate is 200 Pa, the material of the support block is silicon nitride, the size is 10 mm × 10 mm × 5.2 mm, the composition of the sintering aid for the support block is 5% yttrium oxide (mass percentage based on the total mass of silicon nitride and sintering aid) and 5% alumina (mass percentage based on the total mass of silicon nitride and sintering aid), the forming method is dry pressing, and the forming pressure is 50 MPa. The temperature was raised to 1900 °C at a rate of 0.1 - 10 °C / min, held for 6 hours, and then sintered to obtain a sintered silicon nitride substrate.

[0037] 1) Measure the warpage degree of the sintered silicon nitride substrate. The method for measuring the warpage degree is as follows: Place the sintered silicon nitride substrate horizontally, use a three-dimensional laser measuring instrument to scan the entire surface of the silicon nitride substrate, take the height difference between the highest point and the lowest point on the surface as the warpage amount (μm) of the substrate, and the warpage degree is the warpage amount (μm) divided by the length of the diagonal line (mm). The warpage degree of the sintered silicon nitride substrate in Example 1 was 0.5 μm / mm.

[0038] 2) In the present invention, the temperature at which the linear shrinkage rate reaches 5% is defined as the shrinkage start temperature. The sintering linear shrinkage curves of the support block and the substrate were measured using a high-temperature thermal dilatometer, and the results are as shown in Fig. 3. As can be seen from Fig. 3, the shrinkage start temperature of the silicon nitride substrate is 1500 °C, the linear shrinkage rate in the height direction is 17.2%, the shrinkage start temperature of the support block is 1450 °C, and the linear shrinkage rate in the height direction is 20.5%. The shrinkage start temperature of the support block is lower than that of the substrate, and the linear shrinkage rate in the height direction is higher than that of the substrate, realizing a dynamic process from non-contact to contact during sintering.

[0039] Example 2 As arranged as shown in Fig. 1, the size of the silicon nitride substrate is 180 mm × 180 mm × 0.5 mm, the weight of a single silicon nitride substrate is 0.033 kg, the composition of the sintering aid for the silicon nitride substrate is 5% erbium oxide (mass percentage based on the total mass of silicon nitride and the sintering aid), 3% magnesium oxide (mass percentage based on the total mass of silicon nitride and the sintering aid), the forming method is tape casting, the number of layers of the silicon nitride substrate is 15 layers, the thickness of the boron nitride spacer powder in each layer is 100 μm, the material of the pressure plate is boron nitride, the weight is 530 g, the distance between the pressure plate and the nitride ceramic substrate is 0.01 mm, the length and width of the pressure plate are both 20 mm larger than the substrate, the pressure received by the lowermost substrate is 300 Pa, the material of the support block is silicon nitride, the size is 10 mm × 10 mm × 7.8 mm, the composition of the sintering aid for the support block is 5% yttrium oxide (mass percentage based on the total mass of silicon nitride and the sintering aid) and 5% alumina (mass percentage based on the total mass of silicon nitride and the sintering aid), the forming method is dry pressing, and the forming pressure is 50 MPa. The temperature was raised to 1900 °C at a rate of 0.1 - 10 °C / min, held for 6 hours, and then sintered to obtain a sintered silicon nitride substrate.

[0040] 1) The warpage degree of the sintered silicon nitride substrate was measured according to the method of Example 1, and the warpage degree was 0.6 μm / mm.

[0041] 2) Define the temperature at which the linear shrinkage rate reaches 5% as the shrinkage start temperature. Measure the sintering linear shrinkage curves of the support block and the substrate using a high-temperature thermo - dilatometer. The results are as shown in Figure 3. The shrinkage start temperature of the silicon nitride substrate is 1500 °C, the linear shrinkage rate in the height direction is 17.2%, the shrinkage start temperature of the support block is 1450 °C, and the linear shrinkage rate in the height direction is 20.5%. The shrinkage start temperature of the support block is lower than that of the substrate, and the linear shrinkage rate in the height direction is higher than that of the substrate, realizing a dynamic process from non - contact to contact during sintering.

[0042] Example 3 Arrange as shown in Figure 2. The size of the aluminum nitride substrate is 300 mm×300 mm×1.5 mm, the weight of a single aluminum nitride substrate is 145 kg, the number of layers of the aluminum nitride substrate is 1 layer, the composition of the sintering aid for the aluminum nitride substrate is 5% yttrium oxide (mass percentage based on the total mass of aluminum nitride and the sintering aid), the forming method is tape casting, the material of the pressure plate is boron nitride, the weight is 800 g, the distance between the pressure plate and the nitride ceramic substrate is 0.03 mm, the length and width of the pressure plate are both 40 mm larger than the substrate, the material of the support block is aluminum nitride, the size is 20 mm×20 mm×1.52 mm, the composition of the sintering aid for the support block is 10% neodymium oxide (mass percentage based on the total mass of aluminum nitride and the sintering aid), the forming method is dry pressing, and the forming pressure is 20 MPa. Heat up to 1850 °C at a rate of 0.1 - 10 °C / min, hold for 3 hours, and then sinter to obtain a sintered aluminum nitride substrate.

[0043] 1) Measure the warpage degree of the sintered silicon nitride substrate according to the method of Example 1. The warpage degree is 0.8 μm / mm.

[0044] 2) When the linear shrinkage rate is 5%, the temperature at that time is defined as the shrinkage start temperature. The sintering linear shrinkage curves of the support block and the substrate measured by a high-temperature dilatometer are shown in Fig. 4. As can be seen from Fig. 4, the shrinkage start temperature of the substrate is 1500 °C, and the linear shrinkage rate in the height direction is 19.8%. The shrinkage start temperature of the support block is 1600 °C, and the linear shrinkage rate in the height direction is 21.9%. Since the shrinkage start temperature of the support block is higher than that of the substrate and the linear shrinkage rate in the height direction is larger than that of the substrate, a dynamic process from non-contact to contact between the pressure plate and the substrate during sintering was realized.

[0045] It should be noted that the above is only a preferred embodiment of the present invention. Those skilled in the art can make some improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be regarded as within the protection scope of the present invention.

Claims

1. disposing the nitride ceramic substrate between n number of support blocks having the same height in a non-contact manner, disposing a pressure plate above the n number of support blocks having the same height, n≧2, the pressure plate and the nitride ceramic substrate are disposed in parallel, a distance between the pressure plate and the nitride ceramic substrate is 0.01-1 mm, a length of the pressure plate>a length of the nitride ceramic substrate, and a width of the pressure plate>a width of the nitride ceramic substrate; A method for dynamic sintering of a nitride ceramic substrate, comprising the steps of: adjusting a composition of a sintering aid for the support block and / or a molding pressure so that the shrinkage start temperature of the support block is lower or higher than the shrinkage start temperature of the nitride ceramic substrate and the linear shrinkage rate in the height direction of the support block is higher than the linear shrinkage rate in the height direction of the nitride ceramic substrate; and performing sintering to obtain a sintered nitride ceramic substrate; and the sintering process includes a step of increasing the temperature to 1700 to 2000°C at a heating rate of 0.1 to 10°C / min and maintaining the temperature for 1 to 12 hours.

2. 2. The method for dynamic sintering of a nitride ceramic substrate according to claim 1, wherein the nitride ceramic substrate is a silicon nitride substrate or an aluminum nitride substrate, and the method for forming the nitride ceramic substrate is tape casting, dry press molding, gel casting, or tape winding molding.

3. 3. The method for dynamic sintering of a nitride ceramic substrate according to claim 1, wherein the nitride ceramic substrate has a thickness of 0.2 to 2.0 mm, a length of 300 mm or less, and a width of 300 mm or less.

4. 4. The method for dynamic sintering of a nitride ceramic substrate according to claim 3, wherein the nitride ceramic substrate has a thickness of 0.5 to 1.5 mm, a length of 150 mm, and a width of 150 mm.

5. 4. The method for dynamic sintering of a nitride ceramic substrate as claimed in claim 3, wherein the number of the nitride ceramic substrates is 1 or more, and when the number of the nitride ceramic substrates is more than 1, the nitride ceramic substrates are arranged in a stacked manner, the number of stacked layers is 30 or less, adjacent nitride ceramic substrates are separated by a boron nitride separation powder layer, and the thickness of the boron nitride separation powder in different layers is independently 20 to 300 μm.

6. 6. The method for dynamic sintering of nitride ceramic substrates according to claim 5, wherein when the number of the nitride ceramic substrates is more than one, the nitride ceramic substrates are arranged in a stack, the number of stacks is 5-20, and the thickness of the boron nitride spacing powder in different layers is independently 50-200 μm.

7. 2. The method for dynamic sintering of nitride ceramic substrates according to claim 1, wherein the material of the pressure plate is boron nitride, silicon nitride, aluminum nitride or graphite.

8. The formula for calculating the weight of the pressure plate is as follows: [Equation 1] W=P×S / 9.8-(N-1)×W1 Here, P is the pressure received by the bottom nitride ceramic substrate, P = 30 to 500 Pa, and S is the force-receiving area (m ２ 10. The method for dynamic sintering of a nitride ceramic substrate according to claim 1 or 5, wherein N is the number of layers of the nitride ceramic substrate, N=1 to 30, and W1 is the weight (kg) of a single nitride ceramic substrate.

9. 9. The method for dynamic sintering of a nitride ceramic substrate according to claim 1, wherein the distance between the pressure plate and the nitride ceramic substrate is 0.02 to 0.03 mm.

10. 9. The dynamic sintering method for a nitride ceramic substrate according to claim 1 or 8, characterized in that the difference between the length of the pressure plate and the length of the nitride ceramic substrate is 10 mm or more, and the difference between the width of the pressure plate and the width of the nitride ceramic substrate is 10 mm or more.

11. The material of the support block is the same as the material of the nitride substrate, the molding method of the support block is dry press molding or cold isostatic pressing molding, the upper and lower surfaces of the support block are parallel, and the cross-sectional area of ​​the support block is 30 mm ２ 2. The method for dynamic sintering of a nitride ceramic substrate according to claim 1, wherein the method is as described above.

12. 12. The dynamic sintering method for a nitride ceramic substrate according to claim 1 or 11, characterized in that the shrinkage start temperature of the support block is 1300 to 1700°C, and the linear shrinkage rate in the height direction of the support block is 16 to 24%.

13. 13. The method for dynamic sintering of a nitride ceramic substrate according to claim 12, wherein the support block has a shrinkage start temperature of 1450 to 1600°C.

14. The dynamic sintering method for a nitride ceramic substrate according to claim 12 or 13, characterized in that the difference between the shrinkage start temperature of the support block and the shrinkage start temperature of the nitride ceramic substrate is 30 to 100°C, and the difference between the linear shrinkage rate in the height direction of the support block and the linear shrinkage rate in the height direction of the nitride ceramic substrate is 0.2 to 6%.

15. 14. The method for dynamic sintering of a nitride ceramic substrate according to claim 12, wherein a difference between the shrinkage start temperature of the support block and the shrinkage start temperature of the nitride ceramic substrate is 50 to 80°C.

16. The method for dynamic sintering of a nitride ceramic substrate according to claim 12 or 13, characterized in that the heating rate during sintering is 1 to 5°C / min, the temperature is 1850 to 1900°C, and the temperature retention time is 3 to 6 hours.

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