High toughness multilayer ceramic substrate and method of making same

Abstract

The application relates to the technical field of ceramic substrates, and discloses a high-strength and high-toughness multilayer ceramic substrate and a preparation method thereof. The high-strength and high-toughness multilayer ceramic substrate is prepared from the following components in parts by weight: 90-95 parts of alumina, 13-17 parts of a sintering aid, 2-5 parts of a plasticizer, 1-3 parts of a dispersing agent, 3-5 parts of a binder, 10-12 parts of an auxiliary agent and 55-65 parts of water; the auxiliary agent comprises boron carbide, copper-tin alloy powder and graphene oxide. The technical scheme solves the problem of poor toughness of the multilayer ceramic substrate in the related art.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic substrate, in particular, to a high-toughness multilayer ceramic substrate and a preparation method thereof. BACKGROUND

[0002] Multilayer ceramic substrates have excellent insulating properties and high-temperature resistance, and have become key basic materials in the fields of electronic information, new energy, and aerospace. Alumina, silicon nitride, aluminum nitride, and other ceramic substrates have been widely used in power module packaging, sensor carriers, and other scenarios. However, traditional multilayer ceramic materials have exposed their mechanical performance deficiencies in practical applications. Researchers have added non-metallic second phases to ceramic substrate raw materials, but this has not improved the toughness of the ceramic substrate, which has resulted in ceramic substrates that cannot meet the long-term stable service requirements under complex working conditions.

[0003] Under this background, it is an urgent need in the field of ceramic substrates to develop a high-toughness multilayer ceramic substrate. SUMMARY

[0004] The present application proposes a high-toughness multilayer ceramic substrate and a preparation method thereof, solving the problem of poor toughness of multilayer ceramic substrates in related technologies.

[0005] The technical solution of the present application is as follows:

[0006] The present application proposes a high-toughness multilayer ceramic substrate, and the raw materials include the following components by weight: 90-95 parts of alumina, 13-17 parts of sintering aid, 2-5 parts of plasticizer, 1-3 parts of dispersant, 3-5 parts of binder, 10-12 parts of auxiliary agent, and 55-65 parts of water.

[0007] The auxiliary agent includes boron carbide, copper-tin alloy powder, and graphene oxide.

[0008] In the high-toughness multilayer ceramic substrate of the present application, when the sintering aid is added, the sintering aid can promote the densification of the ceramic, reduce defects such as pores, and improve the density and uniformity of the ceramic, thereby ensuring the mechanical properties of the ceramic substrate.

[0009] As a further technical solution, the mass ratio of boron carbide, copper-tin alloy powder, and graphene oxide is 1:1:0.3-0.4.

[0010] In the high-toughness multilayer ceramic substrate of the present application, when the mass ratio of boron carbide, copper-tin alloy powder, and graphene oxide is 1:1:0.3-0.4, the toughness of the ceramic substrate is further improved.

[0011] The mass ratio of boron carbide, copper-tin alloy powder and graphene oxide in the high-toughness multilayer ceramic substrate can be 1:1:0.3, 1:1:0.31, 1:1:0.32, 1:1:0.33, 1:1:0.34, 1:1:0.35, 1:1:0.36, 1:1:0.37, 1:1:0.38, 1:1:0.39, 1:1:0.4, and preferably 1:1:0.3.

[0012] As a further technical solution, the graphene oxide is a graphene oxide composite material.

[0013] The raw material of the graphene oxide composite material includes graphene oxide and 2,4-dihydroxybenzophenone.

[0014] As a further technical solution, the preparation method of the graphene oxide composite material includes the following steps:

[0015] After the graphene oxide is ground, it is added to ethanol, ultrasonically dispersed, mixed uniformly, 2,4-dihydroxybenzophenone is added, stirred, concentrated, and dried to obtain the graphene oxide composite material.

[0016] In the high-toughness multilayer ceramic substrate, the present application focuses on the fact that graphene oxide is prone to agglomeration during the preparation process of the high-toughness multilayer ceramic substrate. Therefore, the present application uses graphene oxide compounded with 2,4-dihydroxybenzophenone as a graphene oxide composite material. The multiple polar groups in the 2,4-dihydroxybenzophenone molecule make the graphene oxide more compatible with other components in the multilayer ceramic substrate system, improving the dispersion of the graphene oxide. Therefore, the raw material distribution of the multilayer ceramic substrate is more uniform, and the bending strength of the multilayer ceramic substrate is improved.

[0017] As a further technical solution, the mass-volume ratio of the graphene oxide and ethanol is 1g:10-15mL.

[0018] As a further technical solution, the power of the ultrasonic dispersion is 100-140W, and the time is 3-5h.

[0019] As a further technical solution, the mass ratio of the graphene oxide and 2,4-dihydroxybenzophenone is 35:2-3.

[0020] In the high-toughness multilayer ceramic substrate, the mass ratio of graphene oxide and 2,4-dihydroxybenzophenone can be 35:2, 35:2.1, 35:2.2, 35:2.3, 35:2.4, 35:2.5, 35:2.6, 35:2.7, 35:2.8, 35:2.9, 35:3, and preferably 35:3.

[0021] As a further technical solution, the stirring speed is 300-400 rpm, the time is 5-6 h, and the temperature is 30-40 DEG C.

[0022] As a further technical solution, the sintering aid includes one or more of silicon dioxide, calcium oxide, magnesium oxide.

[0023] In the high-strength multilayer ceramic substrate, the sintering aid can be any one or more of the conventional sintering aids, and can be any one or more of titanium dioxide, yttrium oxide, cerium oxide, scandium oxide, lanthanum oxide, silicon dioxide, calcium oxide, magnesium oxide, preferably one or more of silicon dioxide, calcium oxide, magnesium oxide.

[0024] As a further technical solution, the plasticizer includes one or both of glycerol and polyethylene glycol.

[0025] As a further technical solution, the dispersant includes one or both of ammonium citrate and sodium polyacrylate.

[0026] In the high-strength multilayer ceramic substrate, the dispersant can be any one or more of the conventional dispersants, and can be any one or more of sodium hexametaphosphate, sodium tripolyphosphate, ammonium citrate, sodium polyacrylate, preferably one or both of ammonium citrate and sodium polyacrylate.

[0027] As a further technical solution, the binder includes one or both of polyvinyl alcohol and hydroxypropyl methylcellulose.

[0028] In the high-strength multilayer ceramic substrate, the binder can be any one or more of the conventional binders, and can be any one or more of carboxymethyl cellulose, polyvinyl alcohol, hydroxypropyl methylcellulose, preferably one or both of polyvinyl alcohol and hydroxypropyl methylcellulose.

[0029] The application also proposes a preparation method of the high-strength multilayer ceramic substrate, for preparing the high-strength multilayer ceramic substrate, comprising the following steps:

[0030] S1, mixing alumina with an aid, ball milling, and then mixing with a sintering aid, a plasticizer, a dispersant and water to obtain a slurry;

[0031] S2, the slurry is flow casted and dried to obtain a blank;

[0032] S3, the blank is perforated, and after surface printing, lamination, up and down conduction, cutting, sintering and cooling, the high-strength multilayer ceramic substrate is obtained.

[0033] As a further technical solution, in step S1, the rotation speed of the ball mill is 500-600 rpm, the time is 2-3 h, and the temperature is 30-50 DEG C.

[0034] The working principle and beneficial effects of the present application are as follows:

[0035] In the present application, boron carbide, copper-tin alloy powder and graphene oxide are added as additives to improve the toughness of the multilayer ceramic substrate, and also to improve the hardness of the ceramic substrate. By synergizing boron carbide, copper-tin alloy powder and graphene oxide, after the crack passes through the copper-tin alloy powder, the copper-tin alloy powder plastically deforms to play a toughening role. Moreover, the present application adds boron carbide and copper-tin alloy powder together as additives to improve the problem of the ceramic substrate hardness decrease caused by the over-soft copper-tin alloy powder, to improve the hardness of the multilayer ceramic substrate. Boron carbide can hinder the shrinkage of the transverse interface of the matrix to achieve the effect of toughening. Graphene oxide as an additive can inhibit grain boundary migration and refine grains to hinder the movement of dislocations, and can dissipate fracture energy when fracture occurs. Graphene oxide, copper-tin alloy powder and boron carbide synergize in different mechanisms when the ceramic substrate is subjected to external force, to improve the toughness of the multilayer ceramic substrate while also improving the hardness of the ceramic substrate. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0037] In the following examples and comparative examples, the tin content in the copper-tin alloy powder is 9.5 wt%, the balance is copper, the particle size is 500 mesh, the particle size of alumina is 1 μm, the particle size of silica is 1 μm, the particle size of calcium oxide is 1 μm, the particle size of magnesium oxide is 1 μm, the type of polyvinyl alcohol is PVA-205, which is purchased from Kureha Corporation, the type of polyethylene glycol is PEG-1000, the type of sodium polyacrylate is NP-800, the particle size of boron carbide is 5000 nm, and the type of graphene oxide is JCGO-99-1-2.

[0038] Example 1

[0039] The raw materials of the high-strength and high-toughness multilayer ceramic substrate include the following components by weight: 95 parts of alumina, 5 parts of silica, 5 parts of calcium oxide, 7 parts of magnesium oxide, 5 parts of glycerol, 3 parts of ammonium citrate, 5 parts of polyvinyl alcohol, 12 parts of additives, and 65 parts of water.

[0040] The additives include boron carbide, copper-tin alloy powder and graphene oxide in a mass ratio of 1:1:0.6.

[0041] The application discloses a preparation method of a high-toughness multilayer ceramic substrate.

[0042] S1, mixing alumina and an additive, ball milling at 50 DEG C for 2h at a rotating speed of 600 rpm, then uniformly mixing with silica, calcium oxide, magnesium oxide, glycerol, ammonium citrate, and water, and adding polyvinyl alcohol to obtain a slurry;

[0043] S2, performing flow casting of the slurry and drying to obtain a green body;

[0044] S3, perforating the green body, performing surface printing, laminating 30 layers, making the upper and lower layers conductive, cutting, sintering at 1650 DEG C for 4.5h, and cooling to obtain the high-toughness multilayer ceramic substrate;

[0045] The raw material for the surface printing is tungsten slurry, and the printing thickness is 15 mu m.

[0046] Embodiment 2

[0047] The high-toughness multilayer ceramic substrate comprises the following components in parts by weight: 90 parts of alumina, 5 parts of silica, 5 parts of calcium oxide, 3 parts of magnesium oxide, 2 parts of polyethylene glycol, 1 part of sodium polyacrylate, 3 parts of hydroxypropyl methyl cellulose, 10 parts of an additive, and 55 parts of water;

[0048] The additive comprises boron carbide, copper-tin alloy powder and graphene oxide at a mass ratio of 1:1:0.2;

[0049] The application discloses a preparation method of a high-toughness multilayer ceramic substrate.

[0050] S1, mixing alumina and an additive, ball milling at 30 DEG C for 3h at a rotating speed of 500 rpm, then uniformly mixing with silica, calcium oxide, magnesium oxide, polyethylene glycol, sodium polyacrylate, and water, and adding hydroxypropyl methyl cellulose to obtain a slurry;

[0051] S2, performing flow casting of the slurry and drying to obtain a green body;

[0052] S3, perforating the green body, performing surface printing, laminating 30 layers, making the upper and lower layers conductive, cutting, sintering at 1680 DEG C for 4h, and cooling to obtain the high-toughness multilayer ceramic substrate;

[0053] The raw material for the surface printing is tungsten slurry, and the printing thickness is 15 mu m.

[0054] Embodiment 3

[0055] The embodiment differs from embodiment 2 only in that the mass ratio of boron carbide, copper-tin alloy powder and graphene oxide is 1:1:0.5.

[0056] Embodiment 4

[0057] The difference between this embodiment and embodiment 2 is only that the mass ratio of boron carbide, copper-tin alloy powder and graphene oxide in this embodiment is 1:1:0.3.

[0058] Example 5

[0059] The difference between this embodiment and embodiment 2 is only that the mass ratio of boron carbide, copper-tin alloy powder and graphene oxide in this embodiment is 1:1:0.4.

[0060] Example 6

[0061] The difference between this embodiment and embodiment 4 is only that the graphene oxide in this embodiment is replaced by an equal mass of graphene oxide composite material, and the preparation method of the graphene oxide composite material comprises the following steps:

[0062] After the graphene oxide is ground and added to ethanol (the mass-volume ratio of graphene oxide and ethanol is 1g:15mL), it is ultrasonically dispersed at a power of 140W for 3h, mixed uniformly, 2,4-dihydroxybenzophenone is added (the mass ratio of graphene oxide and 2,4-dihydroxybenzophenone is 35:3), stirred at a speed of 400rpm for 5h at 40℃, concentrated, dried, and the graphene oxide composite material is obtained.

[0063] Example 7

[0064] The difference between this embodiment and embodiment 4 is only that the graphene oxide in this embodiment is replaced by an equal mass of graphene oxide composite material, and the preparation method of the graphene oxide composite material comprises the following steps:

[0065] After the graphene oxide is ground and added to ethanol (the mass-volume ratio of graphene oxide and ethanol is 1g:10mL), it is ultrasonically dispersed at a power of 100W for 5h, mixed uniformly, 2,4-dihydroxybenzophenone is added (the mass ratio of graphene oxide and 2,4-dihydroxybenzophenone is 35:2), stirred at a speed of 300rpm for 6h at 30℃, concentrated, dried, and the graphene oxide composite material is obtained.

[0066] Comparative Example 1

[0067] The difference between this comparative example and embodiment 2 is only that the auxiliary agent in this comparative example comprises copper-tin alloy powder and graphene oxide in a mass ratio of 1:0.2.

[0068] Comparative Example 2

[0069] The difference between this comparative example and embodiment 2 is only that the auxiliary agent in this comparative example comprises boron carbide and graphene oxide in a mass ratio of 1:0.2.

[0070] Comparative Example 3

[0071] The difference between the present comparative example and Example 2 is that the present comparative example includes boron carbide and copper-tin alloy powder in a mass ratio of 1:1 as the aid.

[0072] Comparative Example 4

[0073] The difference between the present comparative example and Example 2 is that the present comparative example does not include an aid.

[0074] Experimental Example 1

[0075] The high-toughness multilayer ceramic substrate prepared in Examples 1 to 5 and Comparative Examples 1 to 4 was measured for fracture toughness according to the method in GB / T 23806-2009 “Fine Ceramics Fracture Toughness Test Method Single Edge Pre-cracked Beam (SEPB) Method”, and Vickers hardness was measured according to the method specified in GB / T 16534-2009 “Fine Ceramics Hardness Test Method at Room Temperature”. The test results are shown in Table 1.

[0076] Table 1 Test results of fracture toughness and Vickers hardness

[0077]

[0078] As shown in Table 1, the fracture toughness of the high-toughness multilayer ceramic substrate prepared in the present application reached 9.3 MPa·m 1 / 2 The Vickers hardness of 20.2 GPa reached the above, and therefore, the present application uses boron carbide, copper-tin alloy powder and graphene oxide as an aid to improve the fracture toughness of the multilayer ceramic substrate, and also improves the hardness of the multilayer ceramic substrate.

[0079] Experimental Example 2

[0080] The bending strength of the samples was tested according to the test method specified in GB / T 6569-2006 “Fine Ceramics Bending Strength Test Method”, and the test method was three-point bending. The test results are shown in Table 2.

[0081] Table 2 Test results of bending strength

[0082]

[0083] As shown in Table 2, the bending strength of the high-toughness multilayer ceramic substrate prepared in Examples 6 to 7 of the present application reached 477 MPa or more, and therefore, the present application uses graphene oxide compounded with 2,4-dihydroxybenzophenone as a graphene oxide composite material to improve the bending strength of the high-toughness multilayer ceramic substrate.

[0084] The above is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A high toughness multilayer ceramic substrate, characterized by, The raw materials include the following components by weight: 90-95 parts of alumina, 13-17 parts of sintering aid, 2-5 parts of plasticizer, 1-3 parts of dispersant, 3-5 parts of binder, 10-12 parts of auxiliary agent, 55-65 parts of water; The auxiliary agent includes boron carbide, copper-tin alloy powder and graphene oxide; The mass ratio of the boron carbide, copper-tin alloy powder and graphene oxide is 1:1:0.3-0.

4.

2. The high toughness multilayer ceramic substrate of claim 1, wherein, The graphene oxide is a graphene oxide composite material; The raw materials of the graphene oxide composite material include graphene oxide and 2,4-dihydroxybenzophenone.

3. The high toughness multilayer ceramic substrate of claim 2, wherein, The preparation method of the graphene oxide composite material includes the following steps: After the graphene oxide is ground, it is added into ethanol, ultrasonic dispersion, mixing, adding 2,4-dihydroxybenzophenone, stirring, concentrating, drying, to obtain the graphene oxide composite material.

4. The high toughness multilayer ceramic substrate of claim 3, wherein, The power of the ultrasonic dispersion is 100-140W, and the time is 3-5h.

5. The high toughness multilayer ceramic substrate of claim 3, wherein, The mass ratio of the graphene oxide and 2,4-dihydroxybenzophenone is 35:2-3.

6. The high toughness multilayer ceramic substrate of claim 3, wherein, The stirring speed is 300-400rpm, the time is 5-6h, and the temperature is 30-40℃.

7. The high toughness multilayer ceramic substrate of claim 1, wherein, The sintering aid includes one or more of silicon dioxide, calcium oxide and magnesium oxide; The plasticizer includes one or both of glycerol and polyethylene glycol.

8. The high toughness multilayer ceramic substrate of claim 1, wherein, The dispersant includes one or both of ammonium citrate and sodium polyacrylate; The binder includes one or both of polyvinyl alcohol and hydroxypropyl methyl cellulose.

9. A method for producing a high-strength multilayer ceramic substrate according to any one of claims 1 to 8, characterized by, The method includes the following steps: S1, mix the alumina with the auxiliary agent, ball mill, then mix with the sintering aid, plasticizer, dispersant and water, and then add the binder to obtain a slurry; S2, the slurry is flow-casted and dried to obtain a green body; S3, the green body is punched, printed on the surface, laminated, connected up and down, cut, sintered and cooled to obtain the high-toughness multilayer ceramic substrate.

Images