High flexural strength alumina multilayer ceramic substrate and its preparation method

Abstract

This invention relates to the field of ceramic substrate technology, and proposes a high-flexural-resistance alumina multilayer ceramic substrate and its preparation method. The high-flexural-resistance alumina multilayer ceramic substrate comprises the following components by weight: 100 parts composite alumina, 5-8 parts sintering aid, 3-5 parts dispersant, 5-8 parts binder, and 70 parts solvent. The preparation method of the composite alumina includes the following steps: A1, mixing alumina and copper powder evenly, pressing into shape, and sintering to obtain a pre-composite material; A2, dispersing polyvinyl alcohol in water, adding the pre-composite material and feldspar powder, mixing evenly, concentrating, drying, calcining, cooling, and pulverizing to obtain composite alumina; the feldspar powder includes sodium feldspar powder and calcium feldspar powder. Through the above technical solution, the problem of poor flexural resistance of alumina multilayer ceramic substrates in related technologies is solved.

Description

Technical Field

[0001] This invention relates to the field of ceramic substrate technology, and more specifically, to a high-flexural-resistance alumina multilayer ceramic substrate and its preparation method. Background Technology

[0002] Alumina multilayer ceramic substrates are widely used in electronic packaging, integrated circuits, and other fields due to their excellent thermal conductivity and chemical stability. However, as electronic devices develop towards miniaturization, high integration, and high frequency, the market's performance requirements for ceramic substrates are becoming increasingly stringent.

[0003] Alumina, as the primary ceramic material in alumina ceramic substrates, directly influences the performance advantages of alumina multilayer ceramic substrates. Alumina possesses high hardness and heat resistance, providing the ceramic substrate with mechanical support and high-temperature resistance. However, alumina also exhibits inherent defects such as brittleness, sensitivity to surface defects, and rapid crack propagation, making it lack effective resistance to crack propagation under strong external stress. Therefore, directly using alumina in ceramic substrates limits the improvement of their flexural strength. Currently, reinforcing phases such as silicon carbide and mullite can be introduced to refine the grains and adjust their size, thereby improving alumina's resistance to crack propagation. However, grain refinement and internal size adjustment are influenced by various factors such as sintering temperature and material type, making them difficult to achieve and thus hindering the improvement of the flexural strength of ceramic substrates.

[0004] Therefore, developing an alumina multilayer ceramic substrate can effectively improve its flexural strength, which plays an important role in enhancing the overall performance of the alumina multilayer ceramic substrate and extending its service life. Summary of the Invention

[0005] This invention proposes a high-flexural-resistance alumina multilayer ceramic substrate and its preparation method, which solves the problem of poor flexural-resistance of alumina multilayer ceramic substrates in related technologies.

[0006] The technical solution of the present invention is as follows:

[0007] This invention proposes a high-flexural-resistance alumina multilayer ceramic substrate, comprising the following components in parts by weight:

[0008] 100 parts of composite alumina, 5-8 parts of sintering aid, 3-5 parts of dispersant, 5-8 parts of binder, and 70 parts of solvent;

[0009] The preparation method of the composite alumina includes the following steps:

[0010] A1. Mix alumina and copper powder evenly, press into shape, and sinter to obtain a pre-composite material;

[0011] A2. Disperse polyvinyl alcohol in water, add the precomposite and feldspar powder, mix evenly, concentrate, dry, calcine, cool, and pulverize to obtain composite alumina;

[0012] The feldspar powder includes sodium feldspar powder and calcium feldspar powder.

[0013] As a further technical solution, the weight ratio of the alumina to the copper powder is 100:3~8, for example, it can be 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, preferably 100:3, 100:5, 100:8, and more preferably 100:5.

[0014] As a further technical solution, the weight ratio of the alumina to the feldspar powder is 20:2 to 7, for example, it can be 20:2, 20:3, 20:4, 20:5, 20:6, 20:7, preferably 20:3 to 5;

[0015] The weight ratio of the anorthite powder to the sodium feldspar powder is 1.5 to 3:1, for example, it can be 1.5:1, 2:1, 2.5:1, or 3:1, preferably 1.5:1 or 3:1, and more preferably 1.5:1.

[0016] In the high flexural strength alumina multilayer ceramic substrate of the present invention, by adjusting the content of alumina and feldspar powder, when the weight ratio of alumina to feldspar powder is 20:3~5, the flexural strength of the alumina multilayer ceramic substrate can be further improved, and its bending strength can be increased to 448~453MPa.

[0017] As a further technical solution, during the pulverization process, the particle size of the composite alumina is 60~80μm, for example, it can be 60μm, 65μm, 70μm, 75μm, or 80μm, preferably 60μm.

[0018] As a further technical solution, the amount of polyvinyl alcohol added is 3% to 6% of the weight of the alumina.

[0019] As a further technical solution, in step A1, during sintering, the sintering temperature is 1100~1150℃ and the time is 20~30min under a nitrogen atmosphere;

[0020] In step A2, the calcination temperature is 500~600℃ and the time is 50~70min.

[0021] In the high flexural strength alumina multilayer ceramic substrate of the present invention, when copper powder is used to pretreat the alumina, it is carried out in a nitrogen environment. The nitrogen environment can reduce the oxidation of copper powder, thereby reducing the obstruction effect of the oxide film on the copper powder wetting of the alumina.

[0022] As a further technical solution, the preparation method of the composite alumina includes the following steps:

[0023] B1. Mix alumina and copper powder evenly, press them into shape, and sinter them to obtain a pre-composite material;

[0024] B2. Disperse polyvinyl alcohol in water, add the precomposite and feldspar powder, mix evenly, concentrate, dry, calcine, cool, and pulverize to obtain the composite.

[0025] B3. After melting potassium dihydrogen phosphate, add it to the composite, mix evenly, and cool to obtain composite alumina.

[0026] In the high flexural strength alumina multilayer ceramic substrate of this invention, copper powder, sodium feldspar powder, and calcium feldspar powder are used to composite alumina, followed by treatment with potassium dihydrogen phosphate molten salt. The relatively large potassium ions can partially replace the relatively small sodium ions in the sodium feldspar powder on the alumina surface, which can form a surface planar compression to a certain extent. Furthermore, the potassium ions in the potassium dihydrogen phosphate molten salt can penetrate into the pores of the calcium feldspar powder on the surface. After cooling, the molten salt exists in solid form in the surface pores, thereby making the composite alumina surface more compact. This also reduces the shrinkage deformation of the composite alumina during the sintering process in the later preparation of the alumina multilayer ceramic substrate, thereby further improving the flexural strength of the alumina multilayer ceramic substrate, and also improving its fracture toughness to a certain extent.

[0027] As a further technical solution, the weight ratio of potassium dihydrogen phosphate to feldspar powder is 1:2.5~4.

[0028] In the high flexural strength alumina multilayer ceramic substrate of this invention, when the weight ratio of potassium dihydrogen phosphate to feldspar powder is 1:2.5~4, it has a better effect on improving the flexural strength and fracture toughness of the alumina multilayer ceramic substrate. This can further increase the flexural strength of the alumina multilayer ceramic substrate to over 462 MPa and the fracture toughness to 12.9 MPa·m. 1 / 2 above.

[0029] As a further technical solution, in step B3, when the mixture is homogeneous, the temperature is 400~450℃ and the time is 3~4h.

[0030] As a further technical solution, the sintering aid includes one or more of Y2O3, La2O3, and MgF2, preferably La2O3;

[0031] The dispersant includes one or two of tributyl phosphate and polyethylene glycol, preferably polyethylene glycol;

[0032] The adhesive includes one or two of polyvinyl butyral and carboxymethyl cellulose, preferably polyvinyl butyral.

[0033] The solvent includes one or both of ethanol and n-butanol, preferably ethanol.

[0034] This invention proposes a method for preparing a high-flexural-resistance alumina multilayer ceramic substrate, comprising the following steps:

[0035] S1. After mixing all components evenly, ball mill them to obtain the cast slurry;

[0036] S2. Defoaming, casting, and drying of the cast slurry yields raw ceramic sheets;

[0037] S3. The raw ceramic sheet is punched, filled, printed, stacked, laminated, sintered, and cooled to obtain the high flexural strength alumina multilayer ceramic substrate.

[0038] As a further technical solution, the number of layers in the stacking process is 40 to 45.

[0039] As a further technical solution, in step S3, during sintering, the sintering temperature is 1300~1400℃ under a nitrogen atmosphere, and the sintering time is 2~3h.

[0040] The working principle and beneficial effects of this invention are as follows:

[0041] In this invention, a multilayer alumina ceramic substrate with high flexural strength is achieved by composite treatment of alumina with copper powder, calcium feldspar powder, and sodium feldspar powder. This improves the flexural strength of the multilayer alumina ceramic substrate, thereby enhancing its flexural resistance. To reduce the impact of alumina's surface defects and rapid crack propagation on the flexural resistance of the ceramic substrate, this invention first pre-treats the alumina with copper powder to improve its interfacial wettability. Then, the pre-treated alumina is composited with feldspar powder using polyvinyl alcohol, forming a non-expanding feldspar powder coating on the alumina surface. Since the inner alumina layer shrinks more easily than the outer feldspar powder layer after calcination and cooling, compressive stress is generated within the feldspar powder coating. This compressive stress effectively restricts the propagation of alumina cracks, thus improving the flexural resistance of the multilayer alumina ceramic substrate. Detailed Implementation

[0042] The technical solutions 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0043] In the following examples and comparative examples, the average particle size of alumina was 10 μm; the purity of copper powder was 99.9%; the type of polyvinyl alcohol was PVA 1788; the average particle size of sodium feldspar powder was 80 nm; the average particle size of calcium feldspar powder was 80 nm; the type of polyethylene glycol was PEG-1000; and the type of polyvinyl butyral was TB-20.

[0044] Example 1

[0045] The preparation method of composite alumina includes the following steps:

[0046] A1. Mix 100 parts alumina and 3 parts copper powder evenly, press into shape, and sinter at 1100℃ for 30 minutes under nitrogen atmosphere to obtain pre-composite.

[0047] A2. Disperse 3 parts of polyvinyl alcohol in 150 parts of water, add the above pre-composite, 4 parts of sodium feldspar powder and 6 parts of calcium feldspar powder, mix evenly, concentrate, dry, calcine at 500℃ for 70 min, cool, pulverize, and obtain composite alumina with a particle size of 60 μm.

[0048] A method for preparing a high-flexural-resistance alumina multilayer ceramic substrate includes the following steps:

[0049] S1. Mix 100 parts of composite alumina, 5 parts of La2O3, 3 parts of polyethylene glycol, 5 parts of polyvinyl butyral and 70 parts of ethanol evenly, and then ball mill to obtain a casting slurry.

[0050] S2. Defoaming the cast slurry, casting it into shape, and drying it to obtain raw ceramic tiles;

[0051] S3. After punching, filling and printing the green ceramic sheets, stack and laminate 40 layers of green ceramic sheets, sinter at 1300℃ for 3 hours in a nitrogen atmosphere, and then cool to obtain a high-flexibility alumina multilayer ceramic substrate.

[0052] Example 2

[0053] The preparation method of composite alumina includes the following steps:

[0054] A1. Mix 100 parts of alumina and 5 parts of copper powder evenly, press into shape, and sinter at a sintering temperature of 1120℃ for 25 minutes under a nitrogen atmosphere to obtain a pre-composite.

[0055] A2. Disperse 5 parts of polyvinyl alcohol in 150 parts of water, add the above pre-composite, 4 parts of sodium feldspar powder and 6 parts of calcium feldspar powder, mix evenly, concentrate, dry, calcine at 550℃ for 60 min, cool, pulverize, and obtain composite alumina with a particle size of 60 μm.

[0056] A method for preparing a high-flexural-resistance alumina multilayer ceramic substrate includes the following steps:

[0057] S1. Mix 100 parts of composite alumina, 6 parts of La2O3, 4 parts of polyethylene glycol, 6 parts of polyvinyl butyral and 70 parts of ethanol evenly, and then ball mill to obtain a casting slurry.

[0058] S2. Defoaming the cast slurry, casting it into shape, and drying it to obtain raw ceramic tiles;

[0059] S3. After punching, filling and printing the green ceramic sheets, 40 layers of green ceramic sheets are stacked and laminated. Under a nitrogen atmosphere, the sheets are sintered at a sintering temperature of 1350℃ for 2.5 hours and then cooled to obtain a high-flexural-resistance alumina multilayer ceramic substrate.

[0060] Example 3

[0061] The preparation method of composite alumina includes the following steps:

[0062] A1. Mix 100 parts of alumina and 8 parts of copper powder evenly, press into shape, and sinter at a sintering temperature of 1150℃ for 20 minutes under a nitrogen atmosphere to obtain a pre-composite.

[0063] A2. Disperse 6 parts of polyvinyl alcohol in 150 parts of water, add the above pre-composite, 2.5 parts of sodium feldspar powder and 7.5 parts of calcium feldspar powder, mix evenly, concentrate, dry, calcine at 600℃ for 50 min, cool, pulverize, and obtain composite alumina with a particle size of 60 μm.

[0064] A method for preparing a high-flexural-resistance alumina multilayer ceramic substrate includes the following steps:

[0065] S1. Mix 100 parts of composite alumina, 8 parts of La2O3, 5 parts of polyethylene glycol, 8 parts of polyvinyl butyral and 70 parts of ethanol evenly, and then ball mill to obtain a casting slurry.

[0066] S2. Defoaming the cast slurry, casting it into shape, and drying it to obtain raw ceramic tiles;

[0067] S3. After punching, filling and printing the green ceramic sheets, 40 layers of green ceramic sheets are stacked and laminated. Under a nitrogen atmosphere, the sheets are sintered at a sintering temperature of 1400℃ for 2 hours and then cooled to obtain a high-flexural-resistance alumina multilayer ceramic substrate.

[0068] Example 4

[0069] The only difference between this embodiment and Embodiment 2 is that in the preparation method of composite alumina in this embodiment, 6 parts of sodium feldspar powder and 9 parts of calcium feldspar powder are added.

[0070] Example 5

[0071] The only difference between this embodiment and Embodiment 2 is that in the preparation method of composite alumina in this embodiment, 10 parts of sodium feldspar powder and 15 parts of calcium feldspar powder are added.

[0072] Example 6

[0073] The only difference between this embodiment and Embodiment 2 is that in the preparation method of composite alumina in this embodiment, 14 parts of sodium feldspar powder and 21 parts of calcium feldspar powder are added.

[0074] Example 7

[0075] The preparation method of composite alumina includes the following steps:

[0076] B1. Mix 100 parts of alumina and 5 parts of copper powder evenly, press into shape, and sinter at a sintering temperature of 1120℃ for 25 minutes under a nitrogen atmosphere to obtain a pre-composite.

[0077] B2. Disperse 5 parts of polyvinyl alcohol in 150 parts of water, add the above precomposite, 10 parts of sodium feldspar powder and 15 parts of calcium feldspar powder, mix evenly, concentrate, dry, calcine at 550℃ for 60 min, cool, pulverize, and obtain a composite with a particle size of 60 μm.

[0078] B3. After melting 10 parts of potassium dihydrogen phosphate, add the above composite material, mix at 400℃ for 4 hours, cool, and obtain composite alumina;

[0079] A method for preparing a high-flexural-resistance alumina multilayer ceramic substrate includes the following steps:

[0080] S1. Mix 100 parts of composite alumina, 6 parts of La2O3, 4 parts of polyethylene glycol, 6 parts of polyvinyl butyral and 70 parts of ethanol evenly, and then ball mill to obtain a casting slurry.

[0081] S2. Defoaming the cast slurry, casting it into shape, and drying it to obtain raw ceramic tiles;

[0082] S3. After punching, filling and printing the green ceramic sheets, 40 layers of green ceramic sheets are stacked and laminated. Under a nitrogen atmosphere, the sheets are sintered at a sintering temperature of 1350℃ for 2.5 hours and then cooled to obtain a high-flexural-resistance alumina multilayer ceramic substrate.

[0083] Example 8

[0084] The only difference between this embodiment and Embodiment 7 is that in this embodiment, 8 parts of potassium dihydrogen phosphate are added.

[0085] Example 9

[0086] The only difference between this embodiment and Embodiment 7 is that in this embodiment, 6.25 parts of potassium dihydrogen phosphate are added.

[0087] Example 10

[0088] The only difference between this embodiment and Embodiment 7 is that the preparation method of the composite alumina is different in this embodiment, specifically:

[0089] B1. Mix 100 parts of alumina and 5 parts of copper powder evenly, press into shape, and sinter at a sintering temperature of 1120℃ for 25 minutes under a nitrogen atmosphere to obtain a pre-composite.

[0090] B2. Disperse 5 parts of polyvinyl alcohol in 150 parts of water, add the above precomposite, 10 parts of sodium feldspar powder and 15 parts of calcium feldspar powder, mix evenly, concentrate, dry, calcine at 550℃ for 60 min, cool, pulverize, and obtain a composite with a particle size of 60 μm.

[0091] B3. After melting 10 parts of potassium dihydrogen phosphate, add the above composite material, mix at 450°C for 3 hours, and cool to obtain composite alumina.

[0092] Comparative Example 1

[0093] The only difference between this comparative example and Example 2 is that the preparation method of the composite alumina is different in this comparative example, specifically:

[0094] The preparation method of composite alumina includes the following steps:

[0095] 100 parts alumina and 5 parts copper powder were mixed evenly, pressed into shape, sintered at 1150℃ for 25 minutes under nitrogen atmosphere, and then pulverized to obtain composite alumina with a particle size of 60μm.

[0096] Comparative Example 2

[0097] The only difference between this comparative example and Example 2 is that the preparation method of the composite alumina is different in this comparative example, specifically:

[0098] The preparation method of composite alumina includes the following steps:

[0099] Five parts of polyvinyl alcohol were dispersed in 150 parts of water, and 100 parts of alumina, 6 parts of sodium feldspar powder and 4 parts of calcium feldspar powder were added. The mixture was stirred evenly, concentrated, dried and calcined at 550℃ for 60 min. After cooling and pulverizing, composite alumina with a particle size of 60 μm was obtained.

[0100] Comparative Example 3

[0101] The only difference between this comparative example and Example 2 is that the preparation method of the composite alumina is different in this comparative example, specifically:

[0102] The preparation method of composite alumina includes the following steps:

[0103] A1. Mix 100 parts of alumina and 5 parts of copper powder evenly, press into shape, and sinter at a sintering temperature of 1120℃ for 25 minutes under a nitrogen atmosphere to obtain a pre-composite.

[0104] A2. Disperse 5 parts of polyvinyl alcohol in 150 parts of water, add the above pre-composite and 10 parts of albite powder, mix evenly, concentrate, dry, calcine at 550℃ for 60 min, cool, and pulverize to obtain composite alumina with a particle size of 60 μm.

[0105] Comparative Example 4

[0106] The only difference between this comparative example and Example 2 is that the preparation method of the composite alumina is different in this comparative example, specifically:

[0107] The preparation method of composite alumina includes the following steps:

[0108] A1. Mix 100 parts alumina and 5 parts copper powder evenly, press into shape, and sinter at a sintering temperature of 1150℃ for 25 minutes under a nitrogen atmosphere to obtain a pre-composite.

[0109] A2. Disperse 5 parts of polyvinyl alcohol in 150 parts of water, add the above pre-composite and 10 parts of calcium feldspar powder, mix evenly, concentrate, dry, calcine at 550℃ for 60 min, cool, and pulverize to obtain composite alumina with a particle size of 60 μm.

[0110] Experimental Example 1: Bending Strength Test

[0111] The high flexural strength alumina multilayer ceramic substrate samples prepared in Examples 1-10 and Comparative Examples 1-4 were tested for flexural strength according to the three-point bending test method in GB / T 6569-2006 "Test Method for Bending Strength of Fine Ceramics". The test results are shown in Table 1.

[0112] Table 1 Bending strength test results

[0113]

[0114] Compared to Comparative Examples 1-4, the flexural strength of the high-flexural-strength alumina multilayer ceramic substrates prepared in Examples 1-10 increased to over 423 MPa, indicating that composite treatment of alumina with copper powder, sodium feldspar powder, and calcium feldspar powder can improve the flexural strength and flexural resistance of the alumina multilayer ceramic substrates. Furthermore, compared to Example 5, the flexural strength of the high-flexural-strength alumina multilayer ceramic substrates prepared in Examples 7-10 was further improved, indicating that composite treatment of alumina with copper powder, sodium feldspar powder, and calcium feldspar powder, followed by treatment with potassium dihydrogen phosphate molten salt, can further improve the flexural resistance of the alumina multilayer ceramic substrates.

[0115] Experimental Example 2: Fracture Toughness Test

[0116] The high flexural strength alumina multilayer ceramic substrate samples prepared in Examples 5 and 7-10 were tested for fracture toughness according to the method in GB / T23806-2009 "Test Method for Fracture Toughness of Fine Ceramics - Single-sided Precracked Beam (SEPB) Method". The test results are shown in Table 2.

[0117] Table 2. Fracture toughness test results

[0118]

[0119] Compared with Example 5, the fracture toughness of the high flexural strength alumina multilayer ceramic substrates prepared in Examples 7-10 is improved, indicating that the fracture toughness of the alumina multilayer ceramic substrate can also be improved by using copper powder, sodium feldspar powder and calcium feldspar powder to jointly treat alumina and then treating it with potassium dihydrogen phosphate molten salt.

[0120] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-flexural-strength alumina multilayer ceramic substrate, characterized in that, Includes the following components in parts by weight: 100 parts of composite alumina, 5-8 parts of sintering aid, 3-5 parts of dispersant, 5-8 parts of binder, and 70 parts of solvent; The preparation method of the composite alumina includes the following steps: A1. Mix alumina and copper powder evenly, press into shape, and sinter to obtain a pre-composite material; A2. Disperse polyvinyl alcohol in water, add the pre-composite compound and feldspar powder, mix evenly, concentrate, dry, calcine, cool, and pulverize to obtain composite alumina; The feldspar powder includes sodium feldspar powder and calcium feldspar powder.

2. The high flexural strength alumina multilayer ceramic substrate according to claim 1, characterized in that, The weight ratio of the alumina to the copper powder is 100:3~8.

3. The high flexural strength alumina multilayer ceramic substrate according to claim 1, characterized in that, The weight ratio of the alumina to the feldspar powder is 20:2~7; The weight ratio of the calcium feldspar powder to the sodium feldspar powder is 1.5~3:

1.

4. The high flexural strength alumina multilayer ceramic substrate according to claim 1, characterized in that, The amount of polyvinyl alcohol added is 3% to 6% of the weight of the alumina.

5. The high flexural strength alumina multilayer ceramic substrate according to claim 1, characterized in that, In step A1, during sintering, the sintering temperature is 1100~1150℃ and the time is 20~30min under a nitrogen atmosphere; In step A2, the calcination temperature is 500~600℃ and the time is 50~70min.

6. The high flexural strength alumina multilayer ceramic substrate according to claim 1, characterized in that, The preparation method of the composite alumina includes the following steps: B1. Mix alumina and copper powder evenly, press them into shape, and sinter them to obtain a pre-composite material; B2. Disperse polyvinyl alcohol in water, add the precomposite and feldspar powder, mix evenly, concentrate, dry, calcine, cool, and pulverize to obtain the composite. B3. After melting potassium dihydrogen phosphate, add it to the composite, mix evenly, and cool to obtain composite alumina; The feldspar powder includes sodium feldspar powder and calcium feldspar powder.

7. The high flexural strength alumina multilayer ceramic substrate according to claim 6, characterized in that, The weight ratio of potassium dihydrogen phosphate to feldspar powder is 1:2.5~4.

8. The high flexural strength alumina multilayer ceramic substrate according to claim 6, characterized in that, In step B3, when the mixture is homogeneous, the temperature is 400~450℃ and the time is 3~4h.

9. The high flexural strength alumina multilayer ceramic substrate according to claim 1, characterized in that, The sintering aids include one or more of Y2O3, La2O3, and MgF2; The dispersant includes one or both of tributyl phosphate and polyethylene glycol; The adhesive includes one or two of polyvinyl butyral and carboxymethyl cellulose. The solvent includes one or both of ethanol and n-butanol.

10. A method for preparing a high-flexural-strength alumina multilayer ceramic substrate, used to prepare the high-flexural-strength alumina multilayer ceramic substrate as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. After mixing all components evenly, ball mill them to obtain the cast slurry; S2. Defoaming, casting, and drying of the cast slurry yields raw ceramic sheets; S3. The raw ceramic sheet is punched, filled, printed, stacked, laminated, sintered, and cooled to obtain the high flexural strength alumina multilayer ceramic substrate.

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