Thermal-shock-resistant high-toughness multilayer ceramic substrate and preparation method thereof

Abstract

The invention relates to the technical field of ceramic substrates, and provides a thermal-shock-resistant high-toughness multilayer ceramic substrate and a preparation method thereof.The thermal-shock-resistant high-toughness multilayer ceramic substrate is prepared from, by weight, aluminum oxide, a sintering aid, a toughening phase, a binder, a dispersing agent and a solvent; the toughening phase is obtained by sequentially compounding silicon carbide with a first mixture material and a second mixture material; the first mixture material and the second mixture material are respectively and independently prepared from the following raw materials in parts by weight: 1-2 parts of a composite material, 0.5-1 part of a carbon source, 8-10 parts of a solvent and 0.8-1.2 parts of a surfactant; the composite material in the first mixture material consists of silicon carbide and aluminum oxide in a mass ratio of 7: (2-4); the composite material in the second mixture material is prepared from silicon carbide and aluminum oxide in a mass ratio of (3-5): 6. According to the technical scheme, the problems of low thermal shock resistance and low toughness of the multilayer ceramic substrate in the prior art are solved.

Description

TECHNICAL FIELD

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

[0002] In the scene of high power electronic devices, aerospace and other high reliability requirements of multilayer ceramic substrate, the multilayer ceramic substrate needs to have excellent thermal shock resistance and toughness. At present, the method of adding toughening phase in the multilayer ceramic substrate is usually used to improve its thermal shock resistance and toughness, such as silicon carbide, which has certain improvement on thermal shock resistance and toughness, but there is a problem of physical mismatch between silicon carbide and alumina ceramic substrate, which makes the multilayer ceramic substrate cannot achieve the expected toughening effect and improve the effect of thermal shock resistance.

[0003] Therefore, it is necessary to provide a high toughness multilayer ceramic substrate with thermal shock resistance to improve its thermal shock resistance and toughness, and better play the toughening effect of silicon carbide on multilayer ceramic substrate to improve the thermal shock resistance. SUMMARY

[0004] The present application provides a high toughness multilayer ceramic substrate with thermal shock resistance and a preparation method thereof, which solves the problem of low thermal shock resistance and toughness of the multilayer ceramic substrate in the related art.

[0005] The technical scheme of the present application is as follows: The present application provides a high toughness multilayer ceramic substrate with thermal shock resistance, which comprises the following components by weight: 100 parts of alumina, 4-6 parts of sintering aid, 3-5 parts of toughening phase, 6-10 parts of binder, 2-4 parts of dispersant and 50-60 parts of solvent; the toughening phase is composed of first mixture material and second mixture material in sequence; The first mixture material and the second mixture material each independently comprise the following components by weight: 1-2 parts of composite material, 0.5-1 part of carbon source, 8-10 parts of solvent and 0.8-1.2 parts of surfactant; The composite material in the first mixture material is composed of silicon carbide and alumina with a mass ratio of 7:2-4; The composite material in the second mixture material is composed of silicon carbide and alumina with a mass ratio of 3-5:6.

[0006] The addition of sintering aid in the high toughness multilayer ceramic substrate with thermal shock resistance can improve the performance of the multilayer ceramic substrate in the following aspects: 1. improving the density and mechanical properties of the multilayer ceramic substrate, improving the reliability and prolonging the service life; 2. improving the thermal stability and thermal shock resistance, and expanding the application range; 3. reducing the sintering temperature, reducing the adverse effects of high temperature on the multilayer ceramic substrate, and being beneficial to maintaining the performance stability of the multilayer ceramic substrate.

[0007] The addition of the dispersant in the anti-thermal shock high-toughness multilayer ceramic substrate can effectively solve the problem of easy agglomeration of the powder in the multilayer ceramic substrate, improve the dispersibility of the powder, improve the uniformity of the multilayer ceramic substrate, ensure the stability of the multilayer ceramic substrate, and further improve the mechanical strength of the multilayer ceramic substrate.

[0008] As a further technical solution, the sintering aid includes one or more of yttrium oxide, calcium fluoride, and lanthanum oxide.

[0009] As a further technical solution, the binder includes one or both of polyvinyl butyral and sodium carboxymethyl cellulose.

[0010] As a further technical solution, the dispersant includes one or more of ammonium polyacrylate, polyethylene glycol, and stearic acid.

[0011] As a further technical solution, the solvent includes ethanol.

[0012] As a further technical solution, the first mixture material further contains 0.2-0.4 parts of cerium oxide, for example, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, or 0.4 parts; and the second mixture material further contains 0.2-0.4 parts of yttrium oxide, for example, 0.2 parts, 0.25 parts, 0.3 parts, 0.35 parts, or 0.4 parts.

[0013] In the anti-thermal shock high-toughness multilayer ceramic substrate, cerium oxide is added to the first mixture material of silicon carbide, and yttrium oxide is further added to the second mixture material. The addition of cerium oxide and yttrium oxide can improve the density of the overall material after the first mixture material and the second mixture material are compounded and sintered, reduce internal defects, and improve the anti-thermal shock performance of the multilayer ceramic substrate.

[0014] As a further technical solution, the carbon source is a 32wt%-36wt% glucose aqueous solution, for example, 32wt%, 33wt%, 34wt%, 35wt%, or 36wt%.

[0015] As a further technical solution, the preparation method of the toughening phase includes the following steps: A1, after the silicon carbide is uniformly mixed into the first mixture material, spray drying and sintering are performed to obtain a mixture; A2, after the mixture is uniformly mixed into the second mixture material, spray drying and sintering are performed again to obtain a toughening phase.

[0016] As a further technical solution, in step A1, the outlet temperature of the spray drying is 110-120 DEG C, for example, it can be 110 DEG C, 115 DEG C, 120 DEG C, when sintering, the temperature is 320-360 DEG C, for example, it can be 320 DEG C, 330 DEG C, 340 DEG C, 350 DEG C, 360 DEG C, the time is 3-4h, for example, it can be 3h, 3.5h, 4h; In step A2, the outlet temperature of the spray drying is 110-120 DEG C, for example, it can be 110 DEG C, 115 DEG C, 120 DEG C, when sintering, the temperature is 600-650 DEG C, for example, it can be 600 DEG C, 610 DEG C, 620 DEG C, 630 DEG C, 640 DEG C, 650 DEG C, the time is 6-8h, for example, it can be 6h, 6.5h, 7h, 7.5h, 8h.

[0017] As a further technical solution, the mass ratio of the silicon carbide and the first mixture material is 1:3.5-4, for example, it can be 1:3.5, 1:3.6, 1:3.7, 1:3.8, 1:3.9, 1:4, the mass ratio of the mixture and the second mixture material is 1:3.5-4, for example, it can be 1:3.5, 1:3.6, 1:3.7, 1:3.8, 1:3.9, 1:4.

[0018] As a further technical solution, the toughening phase is obtained by sequentially compounding the pretreated silicon carbide, the first mixture material and the second mixture material, the raw material of the pretreated silicon carbide comprises silicon carbide, a solvent, a silane coupling agent and polyacrylamide.

[0019] In the anti-thermal shock high-toughness multilayer ceramic substrate, the silicon carbide is treated by the silane coupling agent and the polyacrylamide before compounding, so that the anti-thermal shock performance of the multilayer ceramic substrate can be further improved.

[0020] As a further technical solution, in the raw material of the pretreated silicon carbide, the solvent comprises water.

[0021] As a further technical solution, in the raw material of the pretreated silicon carbide, the mass sum of the silane coupling agent and the polyacrylamide is 4%-6% of the mass of the silicon carbide.

[0022] As a further technical solution, the mass ratio of the silane coupling agent and the polyacrylamide is 5:1.

[0023] As a further technical solution, the preparation method of the pretreated silicon carbide comprises the following steps: uniformly dispersing the silane coupling agent and the polyacrylamide in the solvent, then adding the silicon carbide, mixing, drying, and obtaining the pretreated silicon carbide.

[0024] As a further technical solution, in the raw material of the pretreated silicon carbide, the mass ratio of the silicon carbide and the solvent is 3:10.

[0025] The application further provides a preparation method of the high-toughness multilayer ceramic substrate against thermal shock. S1, mixing the remaining components except the binder to obtain a slurry; S2, performing defoaming, casting, drying treatment on the slurry to obtain a green ceramic sheet; S3, performing punching, hole filling, surface printing, lamination, pressing, and hot cutting treatment on the green ceramic sheet, and then performing co-firing and cooling to obtain the high-toughness multilayer ceramic substrate against thermal shock.

[0026] As a further technical solution, the co-firing is performed at a temperature of 1100-1250 DEG C for 30-40 min.

[0027] The application has the following working principles and advantages: In the high-toughness multilayer ceramic substrate against thermal shock, the silicon carbide is sequentially compounded by the first mixture material containing silicon carbide and alumina and the second mixture material containing silicon carbide and alumina, and then added into the alumina multilayer ceramic substrate, so that the toughness and thermal shock resistance of the multilayer ceramic substrate can be improved. In the prior art, the use of silicon carbide can improve the toughness and thermal shock resistance of the ceramic substrate, but the physical properties such as the expansion coefficient and the elastic modulus of the silicon carbide are different from those of the matrix of the multilayer ceramic substrate, which causes thermal stress and cracks in the multilayer ceramic substrate, so that the expected toughening effect and the effect of improving the thermal shock resistance cannot be achieved. In the application, the silicon carbide is sequentially compounded by the first mixture material containing silicon carbide and alumina and the second mixture material containing silicon carbide and alumina before being added into the multilayer ceramic substrate, so that the transition of the physical properties of the silicon carbide and the matrix component alumina of the multilayer ceramic substrate can be realized, the thermal stress and cracks in the multilayer ceramic substrate can be reduced, and the toughness and thermal shock resistance of the ceramic substrate can be improved. Moreover, the mass ratio of silicon carbide to alumina in the first mixture material and the second mixture material is limited to 7:2-4, 3-5:6, so that the multilayer ceramic substrate has high toughness. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the application.

[0029] In the following examples and comparative examples: Alumina: average particle size 4 μm; Silicon carbide: average particle size 5 μm; Yttria: average particle size 500 nm; Ceria: average particle size 200 nm; Polyethylene glycol: type PEG400; Polyvinyl butyral: type TB-20.

[0030] Example 1 The anti-thermal shock high-toughness multilayer ceramic substrate comprises raw materials in the following proportions by weight: 100 parts of alumina, 4 parts of yttria, 3 parts of a toughening phase, 6 parts of polyvinyl butyral, 2 parts of polyethylene glycol, and 50 parts of ethanol. The method for preparing the toughening phase comprises the following steps: A1, after the silicon carbide is uniformly mixed into the first mixture material, spray drying (outlet temperature 110°C) and sintering (320°C, 4h) are performed to obtain a mixture; A2, after the mixture is uniformly mixed into the second mixture material, spray drying (outlet temperature 110°C) and sintering (600°C, 8h) are performed to obtain the toughening phase; wherein, The first mixture material comprises raw materials in the following proportions by weight: 1 part of a composite material, 0.5 parts of a 36wt% glucose aqueous solution, 8 parts of ethanol, and 0.8 parts of sodium dodecyl benzene sulfonate; wherein the composite material is composed of silicon carbide and alumina in a mass ratio of 7:2; The second mixture material comprises raw materials in the following proportions by weight: 1 part of a composite material, 0.5 parts of a 36wt% glucose aqueous solution, 8 parts of ethanol, and 0.8 parts of sodium dodecyl benzene sulfonate; wherein the composite material is composed of silicon carbide and alumina in a mass ratio of 3:6; The mass ratio of the silicon carbide and the first mixture material is 1:3.5; The mass ratio of the mixture and the second mixture material is 1:3.5; The method for preparing the anti-thermal shock high-toughness multilayer ceramic substrate comprises the following steps: S1, after the remaining components except for the polyvinyl butyral are once mixed, the polyvinyl butyral is added and twice mixed to obtain a slurry; S2, the slurry is subjected to defoaming, flow casting, and drying treatment to obtain a green ceramic sheet; S3, after the green ceramic sheet is subjected to punching, hole filling, surface printing, lamination (40 layers), pressing, and hot cutting treatment, co-firing (1100°C, 30min) and cooling are performed to obtain the anti-thermal shock high-toughness multilayer ceramic substrate.

[0031] Example 2 The anti-thermal shock high-toughness multilayer ceramic substrate comprises raw materials in the following proportions by weight: 100 parts of alumina, 6 parts of yttria, 5 parts of a toughening phase, 10 parts of polyvinyl butyral, 4 parts of polyethylene glycol, and 60 parts of ethanol. The preparation method of the toughening phase comprises the following steps: A1, after the silicon carbide is uniformly mixed into the first mixture material, spray drying (outlet temperature 120℃) and sintering (360℃, 3h) are performed to obtain a mixture; A2, after the mixture is uniformly mixed into the second mixture material, spray drying (outlet temperature 120℃) and sintering (650℃, 6h) are performed to obtain a toughening phase; wherein, The first mixture material comprises the following components by weight: 2 parts of a composite material, 1 part of a 32wt% glucose aqueous solution, 10 parts of ethanol, and 1.2 parts of sodium dodecyl benzene sulfonate; wherein the composite material is composed of silicon carbide and aluminum oxide in a mass ratio of 7:2; The second mixture material comprises the following components by weight: 2 parts of a composite material, 1 part of a 32wt% glucose aqueous solution, 10 parts of ethanol, and 1.2 parts of sodium dodecyl benzene sulfonate; wherein the composite material is composed of silicon carbide and aluminum oxide in a mass ratio of 3:6; The mass ratio of the silicon carbide and the first mixture material is 1:4; The mass ratio of the mixture and the second mixture material is 1:4; The preparation method of the anti-thermal shock high-toughness multilayer ceramic substrate comprises the following steps: S1, after the remaining components except polyvinyl butyral are once mixed, polyvinyl butyral is added and secondary mixing is performed to obtain a slurry; S2, the slurry is subjected to defoaming, casting molding, and drying treatment to obtain a green ceramic sheet; S3, after the green ceramic sheet is subjected to punching, hole filling, surface printing, lamination (40 layers), pressing, and hot cutting treatment, co-firing (1250℃, 40min) and cooling are performed to obtain an anti-thermal shock high-toughness multilayer ceramic substrate.

[0032] Example 3 Compared with Example 1, the difference of the present embodiment is only that the composite material in the first mixture material is composed of silicon carbide and aluminum oxide in a mass ratio of 7:4.

[0033] Example 4 Compared with Example 1, the difference of the present embodiment is only that the composite material in the first mixture material is composed of silicon carbide and aluminum oxide in a mass ratio of 7:3.

[0034] Example 5 Compared with Example 4, the difference of the present embodiment is only that the composite material in the second mixture material is composed of silicon carbide and aluminum oxide in a mass ratio of 5:6.

[0035] Example 6 The difference between this example and Example 4 is that the composite material in the second mixture material is composed of silicon carbide and alumina with a mass ratio of 4:6.

[0036] Example 7 The difference between this example and Example 6 is that the first mixture material further includes 0.2 parts of cerium oxide.

[0037] Example 8 The difference between this example and Example 7 is that the second mixture material further includes 0.2 parts of yttrium oxide.

[0038] Example 9 The difference between this example and Example 8 is that the silicon carbide in step A1 is pretreated silicon carbide, and the preparation method of the pretreated silicon carbide is: 1.2 parts of silane coupling agent KH-550 is added into 100 parts of water and mixed uniformly, then 30 parts of silicon carbide is added and mixed at 40℃ for 2h, dried to obtain the pretreated silicon carbide.

[0039] Example 10 The difference between this example and Example 9 is that 1.2 parts of silane coupling agent KH-550 in Example 9 is replaced by 1 part of silane coupling agent KH-550 and 0.2 parts of polyacrylamide (weight average molecular weight 18 million).

[0040] Comparative Example 1 The difference between this comparative example and Example 1 is that the first mixture material does not contain a composite material.

[0041] Comparative Example 2 The difference between this comparative example and Example 1 is that the second mixture material does not contain a composite material.

[0042] Comparative Example 3 The difference between this comparative example and Example 1 is that neither the first mixture material nor the second mixture material contains a composite material.

[0043] Comparative Example 4 The difference between this comparative example and Example 1 is that the composite material in the first mixture material is composed of silicon carbide and alumina with a mass ratio of 7:3, and the composite material in the second mixture material is composed of silicon carbide and alumina with a mass ratio of 3:7.

[0044] Comparative Example 5 The difference between this comparative example and Example 1 is that the composite material in the first mixture material is composed of silicon carbide and alumina with a mass ratio of 6:4, and the composite material in the second mixture material is composed of silicon carbide and alumina with a mass ratio of 4:6.

[0045] Comparative Example 6 The difference between the comparative example and Example 1 is only that the toughening phase is only silicon carbide.

[0046] Experimental Example The properties of the multilayer ceramic substrate in Examples 1-10 and Comparative Examples 1-6 were measured, and the measurement method was as follows. (1) Fracture toughness: the fracture toughness was measured according to the method in GB / T 23806-2009 “Fine Ceramic Fracture Toughness Test Method Single Edge Pre-cracked Beam (SEPB) Method”; (2) Thermal shock resistance: the indentation surface was upward, placed on a 180℃ heating platform, and after 30 seconds of heat preservation, pushed into a 25℃ water tank, and after drying the moisture in a 100℃ oven, coated red, and the crack situation was counted. A total of 10 batches were tested, and 5 pieces were randomly selected from each batch for measurement, and finally the crack number accounted for the proportion of the total number of tests; (3) Dielectric constant: the dielectric constant at a frequency of 10GHz was measured according to the method in GB / T 12636-1990 “Microwave Dielectric Substrate Complex Permittivity Strip Line Test Method”; The measurement results are shown in Tables 1-3.

[0047] Table 1 Measurement results of the properties of the multilayer ceramic substrate in Examples 1-6 and Comparative Examples 1-5

[0048] As can be seen from Table 1, the fracture toughness of the multilayer ceramic substrate in Examples 1-6 of the present application is higher than that in Comparative Examples 1-5, which shows that by limiting the different mass ratios of silicon carbide and aluminum oxide in the first mixture material and the second mixture material of silicon carbide, the fracture toughness of the multilayer ceramic substrate can be improved.

[0049] Table 2 Measurement results of the properties of the multilayer ceramic substrate in Examples 1, 6-10 and Comparative Example 6

[0050] As can be seen from Table 2, the thermal shock resistance of the multilayer ceramic substrate in Example 1 and Example 6 is higher than that in Comparative Example 6, which shows that after the first mixture material and the second mixture material containing silicon carbide and aluminum oxide are sequentially compounded, the thermal shock resistance of the multilayer ceramic substrate can be improved. In addition, the thermal shock resistance of the multilayer ceramic substrate in Examples 7-10 is higher than that in Example 6, which shows that by adding cerium oxide in the first mixture material and yttrium oxide in the second mixture material, the thermal shock resistance of the multilayer ceramic substrate can be further improved.

[0051] Table 3 Measurement results of the properties of the multilayer ceramic substrate in Examples 1-2

[0052] The above merely provides the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall fall into the protection scope of the present application.

Claims

1. Thermal shock resistant and high toughness multilayer ceramic substrate, characterized in that: The raw materials include the following components in parts by weight: 100 parts of aluminum oxide, 4-6 parts of sintering aid, 3-5 parts of toughening phase, 6-10 parts of binder, 2-4 parts of dispersant, and 50-60 parts of solvent; the toughening phase is silicon carbide obtained by compounding the first mixture material and the second mixture material in sequence; The first mixture material and the second mixture material each independently comprise the following raw materials in parts by weight: 1-2 parts of composite material, 0.5-1 parts of carbon source, 8-10 parts of solvent, and 0.8-1.2 parts of surfactant; The composite material in the first mixture material is composed of silicon carbide and aluminum oxide in a mass ratio of 7:2-4; The composite material in the second mixture material consists of silicon carbide and aluminum oxide in a mass ratio of 3 to 5:

6.

2. The thermal shock resistant and high toughness multilayer ceramic substrate according to claim 1, characterized in that: The first mixture material further contains 0.2 to 0.4 parts of cerium oxide; and the second mixture material further contains 0.2 to 0.4 parts of yttrium oxide.

3. The thermal shock resistant and high toughness multilayer ceramic substrate according to claim 1, characterized in that: The carbon source is a 32wt% to 36wt% glucose aqueous solution.

4. The thermal shock resistant and high toughness multilayer ceramic substrate according to claim 1, characterized in that: The preparation method of the toughening phase comprises the following steps: A1. Adding silicon carbide to the first mixture material and mixing uniformly, spray drying, and sintering to obtain a mixture; A2. Add the mixture to the second mixture material and mix them evenly, then spray-dry and sinter to obtain a toughening phase.

5. The thermal shock resistant and high toughness multilayer ceramic substrate according to claim 4, characterized in that: Step A1: the outlet temperature of the spray drying is 110-120°C, and the sintering temperature is 320-360°C for 3-4 hours; In step A2, the outlet temperature of the spray drying is 110-120° C., and during the sintering, the temperature is 600-650° C. and the time is 6-8 hours.

6. The thermal shock resistant and high toughness multilayer ceramic substrate according to claim 4, characterized in that: The mass ratio of the silicon carbide to the first mixture material is 1:3.5-4; the mass ratio of the mixture to the second mixture material is 1:3.5-4.

7. The thermal shock resistant and high toughness multilayer ceramic substrate according to claim 1, characterized in that: The toughening phase is obtained by compounding pretreated silicon carbide with a first mixture material and a second mixture material in sequence. The raw materials of the pretreated silicon carbide include silicon carbide, a solvent, a silane coupling agent, and polyacrylamide.

8. The thermal shock resistant and high toughness multilayer ceramic substrate according to claim 7, characterized in that: In the raw materials for pre-treating silicon carbide, the total mass of the silane coupling agent and the polyacrylamide is 4% to 6% of the mass of the silicon carbide.

9. The thermal shock resistant and high toughness multilayer ceramic substrate according to claim 7, characterized in that: The preparation method of the pretreated silicon carbide comprises the following steps: uniformly dispersing a silane coupling agent and polyacrylamide in a solvent, adding silicon carbide, mixing, and drying to obtain the pretreated silicon carbide.

10. A method for preparing a thermal shock resistant and high-toughness multilayer ceramic substrate, for preparing the thermal shock resistant and high-toughness multilayer ceramic substrate according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. After mixing the remaining components except the binder, the binder is added and mixed for a second time to obtain a slurry; S2, degassing, tape casting and drying the slurry to obtain a green porcelain sheet; S3, subjecting the green ceramic sheets to punching, filling, surface printing, lamination, pressing, and thermal cutting, and then to co-firing and cooling to obtain the thermal shock resistant and high-toughness multilayer ceramic substrate.

Images