High-strength wear-resistant multilayer ceramic substrate and method of making same

Abstract

The application relates to the technical field of ceramic substrates, and discloses a high-strength wear-resistant multilayer ceramic substrate and a preparation method thereof.The high-strength wear-resistant multilayer ceramic substrate comprises the following components by weight: 70-80 parts of alumina, 2-3 parts of a dispersing agent, 3-5 parts of a plasticizer, 8-12 parts of a binder, 8-10 parts of a sintering aid and 80-90 parts of water; the alumina is modified alumina; the modified alumina is obtained by modifying alumina with a modifier; and the modifier comprises diphenylsilanediol and a biphenyl compound.The above technical scheme solves the problems of insufficient strength and wear resistance 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, relates to a kind of high-strength wear-resistant multilayer ceramic substrate and preparation method thereof. BACKGROUND

[0002] Alumina ceramic substrate is widely used in integrated circuits, power devices and other fields due to its low cost and stable dielectric properties, but its insufficient wear resistance and strength significantly restrict the high-end application of ceramic substrate, one of the reasons for this problem is the agglomeration of alumina powder.

[0003] The main reason for the agglomeration of alumina powder is the hydroxyl group formed on the surface of the powder. On the one hand, the hydroxyl group on the surface of the powder can connect different particles through hydrogen bonds, especially in a humid environment, the hydrogen bond force significantly enhances the agglomeration tendency. On the other hand, the hydroxyl group on the surface of alumina particles is prone to condensation reaction with the hydroxyl group on the surface of other particles, forming hard agglomerates connected by chemical bonds, which are difficult to break by physical dispersion means. The existence of agglomerates not only forms stress concentration points, which are prone to crack under external force, causing a decrease in strength, but also increases the surface roughness of the ceramic substrate. The protruding parts are prone to fall off due to stress concentration when rubbing, and the hardness inconsistency caused by agglomerates will form preferential wear areas, reducing the wear resistance of the multilayer ceramic substrate.

[0004] Therefore, it is necessary to propose a high-strength wear-resistant multilayer ceramic substrate and a preparation method thereof to solve the problem of insufficient strength and wear resistance caused by the agglomeration of alumina powder. SUMMARY

[0005] The present application proposes a high-strength wear-resistant multilayer ceramic substrate and a preparation method thereof, which solves the problem of insufficient strength and wear resistance of the multilayer ceramic substrate in the related art.

[0006] The technical solution of the present application is as follows: the present application proposes a high-strength wear-resistant multilayer ceramic substrate, which comprises the following components by weight: 70-80 parts of alumina, 2-3 parts of dispersant, 3-5 parts of plasticizer, 8-12 parts of binder, 8-10 parts of sintering aid and 80-90 parts of water. The alumina is modified alumina, which is obtained by modifying alumina with a modifier. The modifier comprises diphenylsilanediol and biphenyl compound.

[0007] As a further technical solution, in the raw material of the modified alumina, the mass ratio of the modifier to the alumina is 4-5:50; for example, it can be 4:50, 4.1:50, 4.2:50, 4.3:50, 4.4:50, 4.5:50, 4.6:50, 4.7:50, 4.8:50, 4.9:50, 1:10, preferably 1:10.

[0008] As a further technical solution, the mass ratio of the diphenylsilanediol and the biphenyl compound is 1-2:1.

[0009] In the raw material of the high-strength wear-resistant multilayer ceramic substrate, the modifier of the modified alumina is composed of diphenylsilanediol and biphenyl compound with a mass ratio of 1-2:1. The diphenylsilanediol can combine with the hydroxyl group on the surface of the alumina, occupy the hydroxyl site on the surface of the alumina, block the further condensation of the hydroxyl group, and introduce a benzene ring with a steric hindrance effect. If the amount of diphenylsilanediol is too small, the coverage of the hydroxyl group on the surface of the alumina is insufficient, and the excessive unoccupied hydroxyl group will still condense to cause agglomeration. The biphenyl compound has a planar rigid structure, and if its content is too high, the rigidity and toughness will be unbalanced, which is not conducive to the bending strength and wear resistance of the multilayer ceramic substrate. When the mass ratio of the diphenylsilanediol and the biphenyl compound is 1-2:1, the diphenylsilanediol can effectively occupy the hydroxyl group on the surface of the alumina and introduce an appropriate amount of benzene ring, and the addition amount of the biphenyl compound is also moderate, which can balance the strength and toughness, and improve the strength and wear resistance of the multilayer ceramic substrate.

[0010] As a further technical solution, the biphenyl compound includes one or more of m-terphenyl, 4-methyl biphenyl, and 4-tert-butyl biphenyl, and preferably 4-tert-butyl biphenyl.

[0011] In the raw material of the high-strength wear-resistant multilayer ceramic substrate, the biphenyl compound in the modifier of the alumina is preferably 4-tert-butyl biphenyl. The reason is that m-terphenyl is formed by three benzene rings to form a planar conjugate, which has the strongest rigidity, and is easy to cause imbalance between strength and toughness. However, due to its planar structure, it can effectively inhibit vertical agglomeration, but it cannot play a good steric hindrance effect in the horizontal direction. 4-methyl biphenyl contains a methyl group in addition to the biphenyl structure. The volume of the methyl group is small, and the rigidity mainly comes from the biphenyl. Therefore, it is not advantageous in terms of rigidity and steric hindrance. The preferred 4-tert-butyl biphenyl contains a tert-butyl group in addition to the biphenyl structure. The rigidity of the tert-butyl group is weaker than that of the benzene ring, and the volume of the tert-butyl group is larger. The presence of the tert-butyl group will occupy a larger space. Therefore, when the biphenyl compound is preferably 4-tert-butyl biphenyl, the performance degradation caused by excessive rigidity can be further avoided, and the strength and wear resistance of the multilayer ceramic substrate can be further improved.

[0012] As a further technical solution, the preparation method of the modified alumina includes the following steps: dispersing the diphenylsilanediol in toluene, adding the alumina, and drying after the first mixing to obtain the pretreated alumina; dispersing the biphenyl compound in toluene, adding the pretreated alumina, and drying after the second mixing to obtain the modified alumina.

[0013] In the raw material of the high-strength wear-resistant multilayer ceramic substrate, in the preparation process of the modified alumina, the alumina is pre-modified by using diphenylsilanediol to occupy the hydroxyl group on the surface of the alumina and introduce benzene rings, and the dispersion of the alumina is preliminarily realized, and then the modified alumina is modified by using a biphenyl compound, the benzene rings interact with each other through the π-π stacking effect, and the dispersion of the alumina powder is further improved, and the introduced biphenyl structure has a certain rigidity, which can further improve the strength and wear resistance of the multilayer ceramic substrate.

[0014] As a further technical solution, in the preparation method of the modified alumina, the mass ratio of the toluene to the alumina is 3-5:1, for example, it can be 3:1, 3.2:1, 3.5:1, 3.8:1, 4:1, 4.2:1, 4.5:1, 4.8:1, 5:1, and preferably 4:1.

[0015] As a further technical solution, the first mixing time is 2-4h, for example, it can be 2h, 2.3h, 2.5h, 2.8h, 3h, 3.5h, 3.8h, 4h, and preferably 3h.

[0016] As a further technical solution, the second mixing time is 3-4h, for example, it can be 3h, 3.1h, 3.2h, 3.3h, 3.4h, 3.5h, 3.6h, 3.7h, 3.8h, 3.9h, 4h, and preferably 3.5h.

[0017] As a further technical solution, the dispersant includes one or both of sodium polyacrylate and polyacrylic acid, and preferably sodium polyacrylate.

[0018] In the raw material of the high-strength wear-resistant multilayer ceramic substrate, a dispersant is added, the dispersant can also prevent powder agglomeration, and uniformly dispersed particles in the raw material mixing stage can avoid sedimentation and stratification, ensure that the composition of each layer of the substrate is consistent, reduce defects such as cracks and pores caused by uneven composition in the subsequent sintering process, and uniformly dispersed particles are more closely contacted during sintering, which helps to improve the surface quality of the multilayer ceramic substrate.

[0019] As a further technical solution, the plasticizer includes one or both of dibutyl phthalate and dioctyl phthalate, and preferably dibutyl phthalate.

[0020] In the raw material of the high-strength wear-resistant multilayer ceramic substrate, a plasticizer is added, the addition of the plasticizer can improve the flowability of the material during the mixing process, thereby making it easier to operate the casting and other forming processes, and the plasticizer has a lubricating and bridging effect on the powder particles, which is beneficial to the dispersion and stability of the slurry, can prevent the ceramic powder particles from settling in the slurry, and makes the slurry maintain uniformity during storage and use, and ensures that the performance of each part of the substrate is consistent.

[0021] As a further technical solution, the binder is polyvinyl alcohol.

[0022] The raw material of the high-strength wear-resistant multilayer ceramic substrate is added with a binder, the addition of the binder can enhance the bonding strength between the raw material components, avoid cracks caused by loose powder, and improve the processing performance of the multilayer ceramic substrate.

[0023] As a further technical solution, the sintering aid includes one or more of magnesium oxide, calcium oxide, and titanium dioxide, preferably magnesium oxide.

[0024] The raw material of the high-strength wear-resistant multilayer ceramic substrate is added with a sintering aid, which can form a low-melting-point liquid phase at high temperatures, can fill the pores in the material, promote the densification of the ceramic substrate, and also inhibit the abnormal growth of crystal grains, forming a fine-grain strengthening structure, and further improving the structural uniformity of the multilayer ceramic substrate.

[0025] The application further provides a preparation method of the high-strength wear-resistant multilayer ceramic substrate.

[0026] S1, after the raw materials are mixed, flow casting and drying are performed to obtain a green ceramic sheet;

[0027] S2, after the green ceramic sheet is punched, surface printed, laminated and compressed, and cut, sintering is performed to obtain the high-strength wear-resistant multilayer ceramic substrate.

[0028] As a further technical solution, the sintering temperature is 1500-1600℃, for example, it can be 1500℃, 1510℃, 1520℃, 1530℃, 1540℃, 1550℃, 1560℃, 1570℃, 1580℃, 1590℃, 1600℃, and preferably 1550℃; the sintering time is 3-4h, for example, it can be 3h, 3.1h, 3.2h, 3.3h, 3.4h, 3.5h, 3.6h, 3.7h, 3.8h, 3.9h, 4h, and preferably 3.5h.

[0029] The working principle and beneficial effects of the application are as follows:

[0030] The raw material of the high-strength wear-resistant multilayer ceramic substrate uses modified alumina modified by diphenylsilanediol and biphenyl compounds as the raw material, solves the agglomeration problem of alumina powder, and improves the strength and wear resistance of the multilayer ceramic substrate. In the prior art, the alumina powder is easily formed into an agglomerate through hydrogen bonding or condensation reaction due to the hydroxyl group formed on the surface thereof, which seriously affects the strength and wear resistance of the multilayer ceramic substrate. In the present application, diphenylsilanediol and biphenyl compounds are used as modifiers. The silanediol in the diphenylsilanediol can react with the hydroxyl group exhibited by the alumina, and then introduce a phenyl group onto the surface of the alumina. The phenyl group has a significant steric hindrance effect, and the modified alumina is difficult to approach due to the mutual repulsion of the phenyl groups, which preliminarily alleviates the agglomeration of the alumina powder. The biphenyl compound has a rigid planar structure and can be adsorbed on the surface of the alumina modified by the diphenylsilanediol through π-π stacking, further improving the strength and wear resistance of the multilayer ceramic substrate. DETAILED DESCRIPTION

[0031] 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 of ordinary skill in the art without creative labor also fall within the scope of protection of the present application.

[0032] In the following examples and comparative examples:

[0033] Alumina: model AG-202G;

[0034] Sodium polyacrylate: weight average molecular weight 2100;

[0035] Polyvinyl alcohol: model PVA1788;

[0036] Magnesium oxide: average particle size 1 μm.

[0037] Example 1

[0038] A preparation method of a high-strength wear-resistant multilayer ceramic substrate, comprising the following steps:

[0039] S1, mixing 70 parts of alumina, 2 parts of sodium polyacrylate, 3 parts of dibutyl phthalate, 8 parts of polyvinyl alcohol, 8 parts of magnesium oxide and 80 parts of water, and then performing flow casting and drying to obtain a green ceramic sheet;

[0040] S2, punching, surface printing, laminating 30 layers, pressing, upper and lower conduction, and cutting the green ceramic sheet, and then sintering at 1550℃ for 3.5h to obtain a high-strength wear-resistant multilayer ceramic substrate;

[0041] The alumina is modified alumina, and a preparation method of the modified alumina comprises the following steps: dispersing diphenylsilanediol in 400 parts of toluene, adding 100 parts of alumina, mixing for 3 hours, and then drying to obtain pretreated alumina; dispersing 4-methylbiphenyl in 400 parts of toluene, adding the pretreated alumina, mixing again for 3.5 hours, and then drying to obtain the modified alumina; wherein the total amount of the diphenylsilanediol and the 4-methylbiphenyl is 10 parts, and the mass ratio of the diphenylsilanediol to the 4-methylbiphenyl is 1:1.

[0042] Example 2

[0043] A preparation method of a high-strength wear-resistant multilayer ceramic substrate comprises the following steps:

[0044] S1, mixing 75 parts of alumina, 2.5 parts of sodium polyacrylate, 4 parts of dibutyl phthalate, 10 parts of polyvinyl alcohol, 9 parts of magnesium oxide and 85 parts of water, and then performing casting forming and drying to obtain a green ceramic sheet;

[0045] S2, performing punching, surface printing, laminating 30 layers, pressing, upper and lower conduction and cutting on the green ceramic sheet, and then sintering at 1550 DEG C for 3.5 hours to obtain the high-strength wear-resistant multilayer ceramic substrate;

[0046] The alumina is modified alumina, and a preparation method of the modified alumina comprises the following steps: dispersing diphenylsilanediol in 400 parts of toluene, adding 100 parts of alumina, mixing for 3 hours, and then drying to obtain pretreated alumina; dispersing 4-methylbiphenyl in 400 parts of toluene, adding the pretreated alumina, mixing again for 3.5 hours, and then drying to obtain the modified alumina; wherein the total amount of the diphenylsilanediol and the 4-methylbiphenyl is 10 parts, and the mass ratio of the diphenylsilanediol to the 4-methylbiphenyl is 1:1.

[0047] Example 3

[0048] A preparation method of a high-strength wear-resistant multilayer ceramic substrate comprises the following steps:

[0049] S1, mixing 80 parts of alumina, 3 parts of sodium polyacrylate, 5 parts of dibutyl phthalate, 12 parts of polyvinyl alcohol, 10 parts of magnesium oxide and 90 parts of water, and then performing casting forming and drying to obtain a green ceramic sheet;

[0050] S2, performing punching, surface printing, laminating 30 layers, pressing, upper and lower conduction and cutting on the green ceramic sheet, and then sintering at 1550 DEG C for 3.5 hours to obtain the high-strength wear-resistant multilayer ceramic substrate;

[0051] The alumina is modified alumina, and a preparation method of the modified alumina comprises the following steps: dispersing diphenylsilanediol in 400 parts of toluene, adding 100 parts of alumina, mixing for 3 hours, and then drying to obtain pretreated alumina; dispersing 4-methylbiphenyl in 400 parts of toluene, adding the pretreated alumina, mixing again for 3.5 hours, and then drying to obtain the modified alumina; wherein the total amount of the diphenylsilanediol and the 4-methylbiphenyl is 10 parts, and the mass ratio of the diphenylsilanediol to the 4-methylbiphenyl is 1:1.

[0052] Example 4

[0053] Compared with Example 1, the difference of Example 4 is that the mass ratio of the diphenylsilanediol to the 4-methylbiphenyl is 2:1.

[0054] Example 5

[0055] Compared with Example 4, the difference of Example 5 is that the 4-methylbiphenyl is replaced by an equal amount of m-terphenyl.

[0056] Example 6

[0057] Compared with Example 4, the difference of Example 6 is that the 4-methylbiphenyl is replaced by an equal amount of 4-tert-butylbiphenyl.

[0058] Comparative Example 1

[0059] Compared with Example 1, the difference of Comparative Example 1 is that the preparation method of the modified alumina is different, and the preparation method of the modified alumina in the present comparative example comprises the following steps: dispersing 10 parts of diphenylsilanediol in 400 parts of toluene, adding 100 parts of alumina, mixing for 3 hours, and then drying to obtain the modified alumina.

[0060] Comparative Example 2

[0061] Compared with Example 1, the difference of Comparative Example 2 is that the preparation method of the modified alumina is different, and the preparation method of the modified alumina in the present comparative example comprises the following steps: dispersing 10 parts of 4-methylbiphenyl in 400 parts of toluene, adding 100 parts of alumina, mixing for 3.5 hours, and then drying to obtain the modified alumina.

[0062] Comparative Example 3

[0063] A preparation method of a high-strength wear-resistant multilayer ceramic substrate comprises the following steps:

[0064] S1, mixing 70 parts of alumina, 2 parts of sodium polyacrylate, 3 parts of dibutyl phthalate, 8 parts of polyvinyl alcohol, 8 parts of magnesium oxide and 80 parts of water, and then performing casting forming and drying to obtain a green ceramic sheet;

[0065] S2, punching, surface printing, laminating 30 layers, up and down conduction, cutting the green ceramic sheet, and sintering at 1550 DEG C for 3.5h to obtain high-strength wear-resistant multilayer ceramic substrate.

[0066] Experimental example 1

[0067] The high-strength wear-resistant multilayer ceramic substrates prepared in examples 1-6 and comparative examples 1-3 were tested according to the following test methods:

[0068] 1. Bending strength: the bending strength of the sample was tested according to the test method (three-point bending method) specified in GB / T 6569-2006 "Fine Ceramic Bending Strength Test Method".

[0069] 2. Wear rate: the ball-on-disc friction and wear test was performed on the sample, and the tribological properties of the sample were tested using a CFT-I type material surface performance comprehensive tester (Lanzhou Zhongke Kaehua Science and Technology Development Co., Ltd.). Under a load of 5N, the wear rate of the sample was tested.

[0070] The test results are shown in Table 1:

[0071] Table 1 Performance test results of high-strength wear-resistant multilayer ceramic substrates prepared in examples 1-6 and comparative examples 1-3

[0072]

[0073] As can be seen from Table 1, when the alumina is modified with diphenylsilanediol first and then modified with a biphenyl compound, the strength and wear resistance of the multilayer ceramic substrate can be further improved.

[0074] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. 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-strength, wear-resistant multilayer ceramic substrate, characterized in that: The invention comprises the following raw materials in parts by weight: 70-80 parts of aluminum oxide, 2-3 parts of a dispersant, 3-5 parts of a plasticizer, 8-12 parts of a binder, 8-10 parts of a sintering aid, and 80-90 parts of water. The aluminum oxide is modified aluminum oxide, which is obtained by modifying aluminum oxide with a modifier, and the modifier includes diphenylsilanediol and a biphenyl compound. The mass ratio of the diphenylsilanediol to the biphenyl compound is 1-2:1; The biphenyl compound is 4-tert-butylbiphenyl.

2. The high-strength, wear-resistant multi-layer ceramic substrate according to claim 1, characterized in that: The preparation method of the modified alumina comprises the following steps: dispersing diphenylsilanediol in toluene, adding alumina, performing a first mixing and then drying to obtain pretreated alumina; dispersing a biphenyl compound in toluene, adding the pretreated alumina, performing a second mixing and then drying to obtain modified alumina.

3. The high-strength, wear-resistant multi-layer ceramic substrate according to claim 1, characterized in that: The dispersant includes one or both of sodium polyacrylate and polyacrylic acid.

4. The high-strength, wear-resistant multi-layer ceramic substrate according to claim 1, characterized in that: The plasticizer includes one or both of dibutyl phthalate and dioctyl phthalate.

5. The high-strength, wear-resistant multi-layer ceramic substrate according to claim 1, characterized in that: The binder is polyvinyl alcohol.

6. The high-strength, wear-resistant multi-layer ceramic substrate according to claim 1, characterized in that: The sintering aid includes one or more of magnesium oxide, calcium oxide, and titanium dioxide.

7. A method for preparing a high-strength, wear-resistant multilayer ceramic substrate, for preparing a high-strength, wear-resistant multilayer ceramic substrate according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, after the raw materials are mixed, tape-cast and dried to obtain green porcelain sheets; S2, punching, surface printing, laminating, pressing, conducting, cutting, and sintering the green ceramic sheets to obtain a high-strength, wear-resistant multi-layer ceramic substrate.

8. The method for preparing a high-strength wear-resistant multi-layer ceramic substrate according to claim 7, characterized in that: The sintering temperature is 1500-1600° C., and the sintering time is 3-4 hours.

Images