Aluminum nitride-based composite ceramic substrate and preparation method thereof

Abstract

The present invention relates to the technical field of ceramic substrate materials, and in particular to an aluminum nitride-based composite ceramic substrate and a preparation method thereof. The aluminum nitride-based composite ceramic substrate is composed of the following raw materials: 105-120 parts of aluminum nitride, 7-14 parts of boron nitride whiskers, 4-8 parts of cordierite, 27-49 parts of a sintering aid, 12-16 parts of a plasticizer, 6-13 parts of a dispersant, 16-25 parts of a binder, and 85-115 parts of an organic solvent. The present invention, by doping barium strontium titanate with cesium zirconate in the aluminum nitride-based substrate material, can not only improve the mechanical properties of the aluminum nitride-based ceramic substrate, such as flexural strength and fracture toughness, but can also further improve the bonding strength of the aluminum nitride-based ceramic substrate to various metals, such as gold, silver, and copper, thereby improving the overall reliability of the ceramic substrate.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic substrate materials, and in particular to an aluminum nitride-based composite ceramic substrate and a preparation method thereof. Background Art

[0002] Aluminum nitride is a covalently bonded compound with [AlN4] tetrahedrons as its structural units. Aluminum nitride has a wurtzite structure and belongs to the hexagonal crystal system. It is a new ceramic material with excellent comprehensive properties. Its lattice constants are a = 0.3110nm, c = 0.4978nm, and its theoretical density is 3.26g / cm3. It has excellent thermal conductivity. Aluminum nitride has attracted widespread attention from researchers both domestically and internationally due to its low thermal expansion coefficient, which is close to that of silicon, high electrical insulation, low dielectric constant and dielectric loss, non-toxicity, good high-temperature mechanical properties, good mechanical properties, and excellent corrosion resistance.

[0003] Aluminum nitride ceramics, with their unique and excellent properties, are becoming increasingly popular in emerging fields such as high-frequency communications, high-power integrated circuits (ICs), high-power IGBT modules, as well as LED lighting, wind power photovoltaic power generation, and new energy vehicles. Since highly integrated, high-power electronic components face a series of problems during operation, such as high currents, high temperatures, and high frequencies, in order to prevent electronic components from failing due to overheating, which affects the reliability of electronic components and circuits, higher requirements are placed on the strength of aluminum nitride ceramic substrates. Sufficiently high strength is required to ensure a long service life for electronic components and reliability between systems. Therefore, the preparation of aluminum nitride ceramics with high thermal conductivity and high strength is an urgent problem that technicians in this field need to solve.

[0004] At the same time, the surface metallization process of ceramic substrates is an important link in realizing the use of ceramics in the packaging of power electronic components. The metallization method determines the performance, manufacturing cost, product yield and scope of use of the ceramic substrate.

[0005] Based on the above situation, the present invention proposes an aluminum nitride-based composite ceramic substrate and a preparation method thereof, which can effectively solve the above problems. Summary of the Invention

[0006] The object of the present invention is to provide an aluminum nitride-based composite ceramic substrate and a preparation method thereof.

[0007] To achieve the above objectives, the present invention provides an aluminum nitride-based composite ceramic substrate, which is composed of the following raw materials: 105-120 parts of aluminum nitride, 7-14 parts of boron nitride whiskers, 4-8 parts of cordierite, 27-49 parts of a sintering aid, 12-16 parts of a plasticizer, 6-13 parts of a dispersant, 16-25 parts of a binder, and 85-115 parts of an organic solvent.

[0008] Preferably, the sintering aid is a rare earth oxide, including at least one or a combination of two or more of yttrium oxide, calcium oxide, niobium oxide, cerium oxide, samarium oxide, and lanthanum oxide.

[0009] Preferably, the plasticizer includes at least one of dibutyl phthalate and glycerol, or a combination of two or more thereof.

[0010] Preferably, the dispersant includes at least one of triolein, triethyl phosphate, sodium polyacrylate, polyacrylate, and castor oil, or a combination of two or more thereof.

[0011] Preferably, the binder is at least one of polyvinyl butyral, acrylate, and polyvinyl alcohol, or a combination of two or more thereof.

[0012] Preferably, the organic solvent includes at least one of anhydrous ethanol, acetone, isopropyl alcohol, and ethyl acetate, or a combination of two or more thereof.

[0013] Preferably, the raw material of the aluminum nitride-based composite ceramic substrate further includes a combination of metal titanate and metal zirconate.

[0014] Preferably, the metal titanate is barium strontium titanate, and the metal zirconate is cesium zirconate.

[0015] Preferably, the aluminum nitride-based composite ceramic substrate is composed of the following raw materials: 95-110 parts of aluminum nitride, 7-14 parts of boron nitride whiskers, 4-8 parts of cordierite, 4-8 parts of barium strontium titanate, 4-10 parts of cesium zirconate, 16-27 parts of cerium oxide, 5-12 parts of yttrium oxide, 6-12 parts of lanthanum oxide, 12-18 parts of dibutyl phthalate, 6-13 parts of triolein, 16-25 parts of polyvinyl butyral, 55-75 parts of isopropyl alcohol, and 30-40 parts of ethyl acetate.

[0016] Preferably, the aluminum nitride-based composite ceramic substrate is composed of the following raw materials: 95 parts of aluminum nitride, 7 parts of boron nitride whiskers, 4 parts of cordierite, 4 parts of strontium barium titanate, 4 parts of cesium zirconate, 16 parts of cerium oxide, 5 parts of yttrium oxide, 6 parts of lanthanum oxide, 12 parts of dibutyl phthalate, 6 parts of triolein, 16 parts of polyvinyl butyral, 55 parts of isopropyl alcohol, and 30 parts of ethyl acetate.

[0017] Preferably, the aluminum nitride-based composite ceramic substrate is composed of the following raw materials: 110 parts of aluminum nitride, 14 parts of boron nitride whiskers, 8 parts of cordierite, 8 parts of barium strontium titanate, 10 parts of cesium zirconate, 27 parts of cerium oxide, 12 parts of yttrium oxide, 12 parts of lanthanum oxide, 18 parts of dibutyl phthalate, 13 parts of triolein, 25 parts of polyvinyl butyral, 75 parts of isopropyl alcohol, and 40 parts of ethyl acetate.

[0018] The present invention also provides a method for preparing an aluminum nitride-based composite ceramic substrate, the preparation method comprising the following steps:

[0019] (1) Aluminum nitride, boron nitride whiskers, cordierite, barium strontium titanate, cesium zirconate, cerium oxide, yttrium oxide, and lanthanum oxide were stirred evenly, and then isopropyl alcohol, triolein, and ethyl acetate were added. After stirring evenly, the mixture was ball-milled and dispersed for 18 to 20 hours to obtain a mixture A;

[0020] (2) Add dibutyl phthalate and polyvinyl butyral to mixture A, stir evenly, and then ball-mill for 10-12 hours to obtain mixture B;

[0021] (3) vacuum degassing the mixture B to obtain a casting slurry, and then performing casting molding to obtain a casting green sheet;

[0022] (4) Sintering the tape-cast green sheet obtained in step (3) in an inert atmosphere at a heating rate of 6 to 8°C / min to a temperature of 1600 to 1650°C and maintaining the temperature for 8 to 10 hours.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention, by doping barium strontium titanate with cesium zirconate in the aluminum nitride-based substrate material, can not only improve the mechanical properties of the aluminum nitride-based ceramic substrate, such as bending strength and fracture toughness, but also further enhance the bonding strength of the aluminum nitride-based ceramic substrate to various metals, such as gold, silver, and copper, thereby improving the overall reliability of the ceramic substrate.

[0025] 2. The raw materials of the present invention are sufficient in China and are reasonably priced, so that there is no high cost limit for large-scale production. Secondly, the combination of the present invention has a wide range of applications and can meet the production requirements of the back adhesive layer of the aluminum nitride-based composite ceramic substrate. At the same time, the preparation process is simple and the overall production cost is not high, which is conducive to large-scale industrial production. DETAILED DESCRIPTION

[0026] Example 1

[0027] Weigh the specific raw materials according to Table 1, and the remaining preparation steps are as follows:

[0028] (1) Aluminum nitride, boron nitride whiskers, cordierite, barium strontium titanate, cesium zirconate, cerium oxide, yttrium oxide, and lanthanum oxide were stirred evenly, and then isopropyl alcohol, triolein, and ethyl acetate were added. After stirring evenly, the mixture was ball-milled and dispersed for 18 hours to obtain a mixture A;

[0029] (2) Add dibutyl phthalate and polyvinyl butyral to mixture A, stir evenly, and then ball-mill for 10 hours to obtain mixture B;

[0030] (3) vacuum degassing the mixture B to obtain a casting slurry, and then performing casting molding to obtain a casting green sheet;

[0031] (4) Sintering the tape-cast green sheet obtained in step (3) in an inert atmosphere at a heating rate of 6°C / min to a temperature of 1600°C and maintaining the temperature for 10 hours.

[0032] Example 2

[0033] Weigh the specific raw materials according to Table 1, and the remaining preparation steps are as follows:

[0034] (1) Aluminum nitride, boron nitride whiskers, cordierite, barium strontium titanate, cesium zirconate, cerium oxide, yttrium oxide, and lanthanum oxide were stirred evenly, and then isopropyl alcohol, triolein, and ethyl acetate were added. After stirring evenly, the mixture was ball-milled and dispersed for 20 hours to obtain a mixture A;

[0035] (2) Add dibutyl phthalate and polyvinyl butyral to mixture A, stir evenly, and then ball-mill for 12 hours to obtain mixture B;

[0036] (3) vacuum degassing the mixture B to obtain a casting slurry, and then performing casting molding to obtain a casting green sheet;

[0037] (4) Sintering the tape-cast green sheet obtained in step (3) in an inert atmosphere at a heating rate of 8°C / min to a temperature of 1650°C and maintaining the temperature for 8 hours.

[0038] Example 3

[0039] Weigh the specific raw materials according to Table 1, and the remaining preparation steps are as follows:

[0040] (1) Aluminum nitride, boron nitride whiskers, cordierite, barium strontium titanate, cesium zirconate, cerium oxide, yttrium oxide, and lanthanum oxide were stirred evenly, and then isopropyl alcohol, triolein, and ethyl acetate were added. After stirring evenly, the mixture was ball-milled and dispersed for 20 hours to obtain a mixture A;

[0041] (2) Add dibutyl phthalate and polyvinyl butyral to mixture A, stir evenly, and then ball-mill for 12 hours to obtain mixture B;

[0042] (3) vacuum degassing the mixture B to obtain a casting slurry, and then performing casting molding to obtain a casting green sheet;

[0043] (4) Sintering the tape-cast green sheet obtained in step (3) in an inert atmosphere at a heating rate of 6°C / min to a temperature of 1650°C and maintaining the temperature for 10 hours.

[0044] Comparative Example 1

[0045] Weigh the specific raw materials according to Table 1, and the remaining preparation steps are as follows:

[0046] (1) Aluminum nitride, boron nitride whiskers, cordierite, cerium oxide, yttrium oxide, and lanthanum oxide were stirred uniformly, and then isopropyl alcohol, triolein, and ethyl acetate were added. After stirring uniformly, the mixture was ball-milled and dispersed for 20 hours to obtain a mixture A;

[0047] (2) Add dibutyl phthalate and polyvinyl butyral to mixture A, stir evenly, and then ball-mill for 12 hours to obtain mixture B;

[0048] (3) vacuum degassing the mixture B to obtain a casting slurry, and then performing casting molding to obtain a casting green sheet;

[0049] (4) Sintering the tape-cast green sheet obtained in step (3) in an inert atmosphere at a heating rate of 6°C / min to a temperature of 1650°C and maintaining the temperature for 10 hours.

[0050] Comparative Example 2

[0051] Weigh the specific raw materials according to Table 1, and the remaining preparation steps are as follows:

[0052] (1) Aluminum nitride, boron nitride whiskers, cordierite, barium strontium titanate, cerium oxide, yttrium oxide, and lanthanum oxide were stirred evenly, and then isopropyl alcohol, triolein, and ethyl acetate were added. After stirring evenly, the mixture was ball-milled and dispersed for 20 hours to obtain a mixture A;

[0053] (2) Add dibutyl phthalate and polyvinyl butyral to mixture A, stir evenly, and then ball-mill for 12 hours to obtain mixture B;

[0054] (3) vacuum degassing the mixture B to obtain a casting slurry, and then performing casting molding to obtain a casting green sheet;

[0055] (4) Sintering the tape-cast green sheet obtained in step (3) in an inert atmosphere at a heating rate of 6°C / min to a temperature of 1650°C and maintaining the temperature for 10 hours.

[0056] Comparative Example 3

[0057] Weigh the specific raw materials according to Table 1, and the remaining preparation steps are as follows:

[0058] (1) Aluminum nitride, boron nitride whiskers, cordierite, cesium zirconate, cerium oxide, yttrium oxide, and lanthanum oxide were stirred uniformly, and then isopropyl alcohol, triolein, and ethyl acetate were added. After stirring uniformly, the mixture was ball-milled and dispersed for 20 hours to obtain a mixture A;

[0059] (2) Add dibutyl phthalate and polyvinyl butyral to mixture A, stir evenly, and then ball-mill for 12 hours to obtain mixture B;

[0060] (3) vacuum degassing the mixture B to obtain a casting slurry, and then performing casting molding to obtain a casting green sheet;

[0061] (4) Sintering the tape-cast green sheet obtained in step (3) in an inert atmosphere at a heating rate of 6°C / min to a temperature of 1650°C and maintaining the temperature for 10 hours.

[0062] Comparative Example 4

[0063] Weigh the specific raw materials according to Table 1, and the remaining preparation steps are as follows:

[0064] (1) Aluminum nitride, boron nitride whiskers, cordierite, barium strontium titanate, bismuth titanate, cerium oxide, yttrium oxide, and lanthanum oxide were stirred uniformly, and then isopropyl alcohol, triolein, and ethyl acetate were added. After stirring uniformly, the mixture was ball-milled and dispersed for 20 hours to obtain a mixture A;

[0065] (2) Add dibutyl phthalate and polyvinyl butyral to mixture A, stir evenly, and then ball-mill for 12 hours to obtain mixture B;

[0066] (3) vacuum degassing the mixture B to obtain a casting slurry, and then performing casting molding to obtain a casting green sheet;

[0067] (4) Sintering the tape-cast green sheet obtained in step (3) in an inert atmosphere at a heating rate of 6°C / min to a temperature of 1650°C and maintaining the temperature for 10 hours.

[0068] Table 1

[0069]

[0070] Example 4 Performance Test

[0071] The thermal conductivity, flexural strength, and fracture toughness of the composite ceramic substrates prepared in Examples 1-3 and Comparative Examples 1-4 were tested. A 10 μm thick metal film was sputtered onto the composite ceramic substrates prepared in Examples 1-3 and Comparative Examples 1-3 using copper, silver, and gold as the metal raw materials, and the bonding strength was measured. The test results are shown in Table 2.

[0072] Table 2 Performance test results

[0073]

[0074] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. An aluminum nitride-based composite ceramic substrate, characterized in that: The aluminum nitride-based composite ceramic substrate is composed of the following raw materials: 95-110 parts of aluminum nitride, 7-14 parts of boron nitride whiskers, 4-8 parts of cordierite, 4-8 parts of barium strontium titanate, 4-10 parts of cesium zirconate, 16-27 parts of cerium oxide, 5-12 parts of yttrium oxide, 6-12 parts of lanthanum oxide, 12-18 parts of dibutyl phthalate, 6-13 parts of triolein, 16-25 parts of polyvinyl butyral, 55-75 parts of isopropyl alcohol, and 30-40 parts of ethyl acetate.

2. A method for preparing the aluminum nitride-based composite ceramic substrate according to claim 1, characterized in that: The method comprises the following steps: (1) Aluminum nitride, boron nitride whiskers, cordierite, barium strontium titanate, cesium zirconate, cerium oxide, yttrium oxide, and lanthanum oxide were stirred evenly, and then isopropyl alcohol, triolein, and ethyl acetate were added. After stirring evenly, the mixture was ball-milled and dispersed for 18 to 20 hours to obtain a mixture A; (2) Add dibutyl phthalate and polyvinyl butyral to mixture A, stir evenly, and then ball-mill for 10 to 12 hours to obtain mixture B; (3) vacuum degassing the mixture B to obtain a casting slurry, and then performing casting molding to obtain a casting green sheet; (4) Sintering the tape-cast green sheet obtained in step (3) in an inert atmosphere at a heating rate of 6 to 8°C / min to a temperature of 1600 to 1650°C and maintaining the temperature for 8 to 10 hours.

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