Low dielectric constant multilayer ceramic substrate and preparation method thereof

Abstract

The invention relates to the technical field of ceramic substrates, and provides a low-dielectric-constant multilayer ceramic substrate and a preparation method thereof. The low-dielectric-constant multilayer ceramic substrate comprises the following components in parts by weight: 100 parts of aluminum oxide, 4-8 parts of a sintering aid, 8-16 parts of silicate, 3-6 parts of copper oxide, 3-5 parts of a dispersing agent, 6-12 parts of a binder and 70 parts of a solvent, the silicate comprises magnesium aluminum silicate and zirconium silicate in a weight ratio of (1.5-9): 1. According to the technical scheme, the problem that the bending strength of the multi-layer ceramic substrate is poor in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic substrates, and specifically, to a low dielectric constant multi-layer ceramic substrate and a preparation method thereof. Background Art

[0002] With the development of electronic devices towards high frequency and integration, as a carrier of key electronic components, the performance requirements for multi-layer ceramic substrates are becoming increasingly stringent. Among them, the flexural strength is one of the core indicators for measuring the reliability of ceramic substrates, directly affecting the anti-fracture ability and long-term stability of the substrates during processing, assembly and use. Especially in high temperature, high humidity or mechanical stress environments, insufficient flexural strength will lead to substrate cracking, delamination or even functional failure, seriously affecting the life and reliability of electronic devices.

[0003] The prior art usually enhances the bonding force between ceramic powders by adding organic binders or other additives. These binders can form a network structure in the green ceramic stage, improving the green body strength to a certain extent. However, they will decompose and volatilize during the high-temperature sintering process, resulting in pores inside the substrate, reducing the density, and thus having limited improvement in the flexural strength of the ceramic substrate. In addition, excessive use of binders may introduce impurities, affecting the overall performance of the multi-layer ceramic substrate.

[0004] Therefore, developing a multi-layer ceramic substrate with good flexural strength is of great significance for improving the service life of multi-layer ceramic substrates and expanding their application scope. Summary of the Invention

[0005] The present invention provides a low dielectric constant multi-layer ceramic substrate and a preparation method thereof, solving the problem of poor flexural strength of multi-layer ceramic substrates in related technologies.

[0006] The technical solution of the present invention is as follows: The present invention provides a low dielectric constant multi-layer ceramic substrate, comprising the following components in parts by weight: 100 parts of alumina, 4 - 8 parts of sintering aid, 8 - 16 parts of silicate, 3 - 6 parts of copper oxide, 3 - 5 parts of dispersant, 6 - 12 parts of binder, 70 parts of solvent; The silicate includes magnesium aluminum silicate and zirconium silicate with a weight ratio of 1.5 - 9:1.

[0007] In the present invention, the sintering aid of the low dielectric constant multi-layer ceramic substrate can reduce the sintering temperature of the green tape of the low dielectric constant multi-layer ceramic substrate, forming a eutectic phase or solid solution with a low melting point, thereby realizing the densification of the low dielectric constant multi-layer ceramic substrate at a lower temperature. The sintering aid can be any one or more conventional sintering aids in the art. For example, it can be Y 2 O 3 、CaF 2 、La2 O 3 One or more of them, preferably Y 2 O 3 .

[0008] In the present invention, in the low dielectric constant multi-layer ceramic substrate, the addition of a dispersant can adsorb on the surface of inorganic powder particles, and through steric hindrance and electrostatic repulsion, the inorganic powder particles are separated from each other, reducing the agglomeration of inorganic powder particles, forming a uniform and stable tape-casting slurry, improving the stability of the green ceramic sheet. The dispersant can be any one or more conventional dispersants in the art. For example, it can be one or two of tributyl phosphate and polyethylene glycol, preferably polyethylene glycol.

[0009] In the present invention, in the low dielectric constant multi-layer ceramic substrate, the binder can bond the inorganic powder particles in the low dielectric constant multi-layer ceramic substrate together to form a green ceramic sheet that is not easily deformed or cracked. Additionally, and most importantly, the binder forms a network structure between the inorganic powder particles, increasing the binding force between the particles, thereby improving the overall strength of the green ceramic sheet, and further endowing the low dielectric constant multi-layer ceramic substrate with basic flexural strength. The binder can be any one or more conventional binders in the art. For example, it can be one or two of hydroxypropyl methylcellulose and polyvinyl butyral, preferably polyvinyl butyral.

[0010] As a further technical solution, the weight ratio of magnesium aluminum silicate to zirconium silicate is 3 - 5:1.

[0011] In the present invention, the low dielectric constant multi-layer ceramic substrate uses alumina as the matrix. Alumina itself has good chemical stability, which can provide basic mechanical strength and structural support for the low dielectric constant multi-layer ceramic substrate. Under the combined action of a sintering aid, silicate, copper oxide, dispersant, binder, and solvent, a low dielectric constant multi-layer ceramic substrate with a dense and stable internal structure can be formed, having good flexural strength.

[0012] In the present invention, the silicate includes magnesium aluminum silicate and zirconium silicate, and the weight ratio of the two is 1.5 - 9:1. For example, it can be 1.5:1, 2:1, 3:1, 4:1, 5:1, 8:1, 9:1, preferably 1.5:1, 3:1, 5:1, 9:1, and more preferably 3:1, 5:1. In the present invention, when the weight ratio of magnesium aluminum silicate to zirconium silicate is 3 - 5:1, the flexural strength of the low dielectric constant multi-layer ceramic substrate can be further improved, and the flexural strength can reach 484 - 489 MPa. When the weight ratio of magnesium aluminum silicate to zirconium silicate is outside the range of 3 - 5:1, the improvement effect on the bending strength of the low dielectric constant multi-layer ceramic substrate is poor.

[0013] As a further technical solution, the silicate is a boron composite silicate, and the raw materials of the boron composite silicate include silicate, boron source, and cage-shaped polyhedral oligomeric silsesquioxane.

[0014] As a further technical solution, the boron source includes an organic boron source and an inorganic boron source; The organic boron source includes benzeneboronic acid compounds; The inorganic boron source includes one or more of magnesium metaborate, lithium metaborate, and sodium metaborate.

[0015] In the present invention, the silicate is compounded with a boron source and cage-shaped polyhedral oligomeric silsesquioxane. While not affecting the flexural strength of the multilayer ceramic substrate, the dielectric constant of the multilayer ceramic substrate can be reduced. The possible reason is speculated as follows: Introducing a boron source into the silicate can form boron-oxygen bonds, which to a certain extent improves the stability of the silicate crystal structure, thereby reducing the polarization degree of the silicate under the action of an electric field. At the same time, introducing cage-shaped polyhedral oligomeric silsesquioxane can improve the interfacial bonding effect between the silicate and the components of the multilayer ceramic substrate through compound treatment. While not affecting the flexural strength of the multilayer ceramic substrate, the dielectric constant of the multilayer ceramic substrate can be reduced.

[0016] In the present invention, the boron source is an organic boron source and an inorganic boron source. By using the organic boron source and the inorganic boron source together, the silicate is pretreated with the organic boron source first, which can improve the subsequent combination degree with the inorganic boron source. At the same time, the presence of the organic boron source can promote the better combination of the cage-shaped polyhedral oligomeric silsesquioxane and the silicate to a certain extent, thus contributing to the successful preparation of the boron composite silicate.

[0017] In the present invention, the benzeneboronic acid compounds include one or more of benzeneboronic acid, p-methylbenzeneboronic acid, and p-hydroxymethylbenzeneboronic acid, and preferably p-hydroxymethylbenzeneboronic acid.

[0018] As a further technical solution, in the raw materials of the boron composite silicate, the weight ratio of the silicate, cage-shaped polyhedral oligomeric silsesquioxane, and boron source is 30:4:1 to 4. For example, it can be 30:4:1, 30:4:2, 30:4:3, 30:4:3.2, 30:4:3.5, 30:4:4. Preferably, it is 30:4:1, 30:4:2, 30:4:3.2, 30:4:4, and more preferably 30:4:2, 30:4:3.2.

[0019] In the present invention, when the weight ratio of the silicate, cage-shaped polyhedral oligomeric silsesquioxane, and boron source is 30:4:1 to 4, the dielectric constant of the multilayer ceramic substrate can be reduced to below 6.3. When the weight ratio of the silicate, cage-shaped polyhedral oligomeric silsesquioxane, and boron source is 30:4:2 to 3.2, the dielectric constant of the multilayer ceramic substrate can be further reduced to 5.3 to 5.6.

[0020] As a further technical solution, the weight ratio of the organic boron source to the inorganic boron source is 1:1 to 3, for example, it can be 1:1, 1:1.5, 1:2, 1:2.5, 1:3, preferably 1:1, 1:3, and more preferably 1:3.

[0021] As a further technical solution, the preparation method of the boron composite silicate comprises the following steps: A1. Disperse the organic boron source in absolute ethanol, add the silicate, mix evenly, concentrate, and dry to obtain a silicate mixture A; A2. Blend the silicate mixture A, the inorganic boron source and water together, ball mill, and dry to obtain a silicate mixture B; A3. Disperse the cage-type polyhedral oligomeric silsesquioxane in dimethylformamide, add the silicate mixture B, mix evenly, concentrate, dry, and calcine to obtain the boron composite silicate.

[0022] As a further technical solution, in step A1, the addition amount of the absolute ethanol is 4 to 5 times the weight of the organic boron source, for example, it can be 4 times, 4.2 times, 4.4 times, 4.5 times, 4.6 times, 4.8 times, 5 times, and preferably 4.4 times.

[0023] As a further technical solution, in step A2, the addition amount of the water is 3 to 4 times the weight of the inorganic boron source, for example, it can be 3 times, 3.1 times, 3.2 times, 3.5 times, 3.8 times, 4 times, and preferably 4 times.

[0024] As a further technical solution, in step A2, during the ball milling, the ball milling speed is 250 to 330 rpm, and the ball milling time is 3 to 4 h.

[0025] As a further technical solution, in step A3, the addition amount of the dimethylformamide is 5 to 7 times the weight of the cage-type polyhedral oligomeric silsesquioxane, for example, it can be 5 times, 5.5 times, 5.8 times, 6 times, 6.5 times, 7 times, and preferably 6 times.

[0026] As a further technical solution, in step A3, when mixing evenly, in a stirring manner, the stirring speed is 250 to 330 rpm, and the stirring time is 30 to 50 min.

[0027] As a further technical solution, in step A3, during the calcination, the temperature is 350 to 370 °C, for example, it can be 350 °C, 360 °C, 365 °C, 370 °C, preferably 365 °C, and the time is 40 to 60 min, for example, it can be 40 min, 45 min, 50 min, 55 min, 60 min, and preferably 50 min.

[0028] As a further technical solution, the solvent includes one or both of ethanol and acetone, preferably ethanol.

[0029] The present invention provides a method for preparing a low dielectric constant multi-layer ceramic substrate, which is used to prepare the low dielectric constant multi-layer ceramic substrate, and includes the following steps: S1. Blend the remaining components except the binder, disperse them evenly, then add the binder and mix evenly to obtain a casting slurry. S2. Subject the casting slurry to defoaming, casting, drying, and stamping to obtain a green tape. S3. Subject the green tape to punching, hole filling, printing, laminating, pressing, sintering, and cooling to obtain the low dielectric constant multi-layer ceramic substrate.

[0030] As a further technical solution, in step S3, when laminating, the number of layers is 30 to 45, for example, it can be 30, 32, 35, 40, 42, 45, preferably 30, 40, 45, and more preferably 40.

[0031] As a further technical solution, in step S3, when sintering, the sintering atmosphere is air, the sintering temperature is 1100 to 1250 °C, for example, it can be 1100 °C, 1120 °C, 1150 °C, 1165 °C, 1170 °C, 1180 °C, 1200 °C, 1250 °C, preferably 1100 °C, 1250 °C, 1180 °C, and the sintering time is 20 to 40 min, for example, it can be 20 min, 30 min, 40 min.

[0032] As a further technical solution, in step S3, the material for printing is tungsten paste, and the printing thickness of the tungsten paste is 16 to 18 μm, for example, it can be 16 μm, 16.5 μm, 17 μm, 18 μm, preferably 16 μm, 17 μm, 18 μm, and more preferably 17 μm.

[0033] The working principle and beneficial effects of the present invention are as follows: 1. In the present invention, silicates are introduced into the low dielectric constant multi-layer ceramic substrate. The silicates include magnesium aluminum silicate and zirconium silicate. By using magnesium aluminum silicate and zirconium silicate together, the flexural strength of the low dielectric constant multi-layer ceramic substrate can be effectively improved. In the prior art, organic binder aids in the ceramic substrate are often used to improve the bonding effect between ceramic powders to enhance the flexural strength of the multi-layer ceramic substrate. However, since the organic binder aids decompose at high temperatures, the internal density of the ceramic substrate is reduced, resulting in limited improvement in the flexural strength of the low dielectric constant multi-layer ceramic substrate. The present invention not only pays attention to the inherent strengthening effect of the binder component in the ceramic substrate, but also pays attention to the influence of the complexity of the self-assembly of the inorganic components inside the ceramic substrate on the flexural strength of the ceramic substrate. Two silicates, magnesium aluminum silicate and zirconium silicate, are introduced into the low dielectric constant multi-layer ceramic substrate. By using magnesium aluminum silicate and zirconium silicate together, while jointly supporting with alumina, it can also enhance the interfacial bonding with the alumina matrix during the sintering process, hinder the crack propagation of the ceramic substrate during the sintering process, and thus improve the flexural strength of the low dielectric constant multi-layer ceramic substrate.

[0034] 2. In the present invention, the content ratio of magnesium aluminum silicate and zirconium silicate is reasonably adjusted to 1.5 - 9:1, which can enable magnesium aluminum silicate and zirconium silicate to exert a good synergistic effect, increase the flexural strength of the low dielectric constant multi-layer ceramic substrate to more than 468 MPa, and have good ability to resist external stress. Specific embodiments

[0035] Hereinafter, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of the present invention.

[0036] In the following examples and comparative examples, the polyvinyl butyral has the model of TB-20; the polyethylene glycol has the model of PEG400; the particle size of magnesium aluminum silicate is 30 μm; the particle size of zirconium silicate is 45 μm; the viscosity of the cage-shaped polyhedral oligomeric silsesquioxane is 2200 cps.

[0037] Example 1 A method for preparing a low dielectric constant multi-layer ceramic substrate, comprising the following steps: S1. Blend 100 parts of alumina, 4 parts of Y 2 O 3 , 4.8 parts of magnesium aluminum silicate, 3.2 parts of zirconium silicate, 3 parts of copper oxide, 3 parts of polyethylene glycol and 70 parts of ethanol, disperse evenly, and then add 6 parts of polyvinyl butyral and mix evenly to obtain a casting slurry; S2. Defoam the casting slurry, perform casting forming, drying, and stamping to obtain a green ceramic tape; S3. Punch holes in the green ceramic tape, fill the holes, print a tungsten paste material with a thickness of 17 μm, stack and laminate 30 layers of the green ceramic tape, sinter in an air atmosphere at 1100 °C for 40 min, and cool to obtain a low dielectric constant multi-layer ceramic substrate.

[0038] Example 2 A method for preparing a low dielectric constant multi-layer ceramic substrate, comprising the following steps: S1. Blend 100 parts of alumina, 6 parts of Y 2 O 3 , 7.2 parts of magnesium aluminum silicate, 4.8 parts of zirconium silicate, 5 parts of copper oxide, 4 parts of polyethylene glycol, and 70 parts of ethanol, disperse evenly, and then add 8 parts of polyvinyl butyral, mix evenly to obtain a casting slurry; S2. Defoam the casting slurry, perform casting forming, drying, and stamping to obtain a green ceramic tape; S3. Punch holes in the green ceramic tape, fill the holes, print a tungsten paste material with a thickness of 17 μm, stack and laminate 40 layers of the green ceramic tape, sinter in an air atmosphere at 1180 °C for 30 min, and cool to obtain a low dielectric constant multi-layer ceramic substrate.

[0039] Example 3 A method for preparing a low dielectric constant multi-layer ceramic substrate, comprising the following steps: S1. Blend 100 parts of alumina, 8 parts of Y 2 O 3 , 14.4 parts of magnesium aluminum silicate, 1.6 parts of zirconium silicate, 6 parts of copper oxide, 5 parts of polyethylene glycol, and 70 parts of ethanol, disperse evenly, and then add 12 parts of polyvinyl butyral, mix evenly to obtain a casting slurry; S2. Defoam the casting slurry, perform casting forming, drying, and stamping to obtain a green ceramic tape; S3. Punch holes in the green ceramic tape, fill the holes, print a tungsten paste material with a thickness of 17 μm, stack and laminate 45 layers of the green ceramic tape, sinter in an air atmosphere at 1250 °C for 20 min, and cool to obtain a low dielectric constant multi-layer ceramic substrate.

[0040] Example 4 The difference between this example and Example 2 is only that in this example, 10.8 parts of magnesium aluminum silicate and 1.2 parts of zirconium silicate are added.

[0041] Example 5 The difference between this example and Example 2 is only that in this example, 9 parts of magnesium aluminum silicate and 3 parts of zirconium silicate are added.

[0042] Example 6 The difference between this example and Example 2 is only that in this example, 10 parts of magnesium aluminum silicate and 2 parts of zirconium silicate are added.

[0043] Example 7 The difference between this example and Example 6 is only that in this example, the silicate is a boron composite silicate, and the preparation method of the boron composite silicate includes the following steps: A1. Disperse 0.5 part of p-hydroxymethylphenylboronic acid in 2.2 parts of absolute ethanol, add 25 parts of magnesium aluminum silicate and 5 parts of zirconium silicate, mix evenly, concentrate, and dry to obtain a silicate mixture A; A2. Blend the above silicate mixture A, 0.5 part of magnesium metaborate and 2 parts of water, ball-mill at a ball-milling speed of 300 rpm for 3.5 h, and dry to obtain a silicate mixture B; A3. Disperse 4 parts of cage-type polyhedral oligomeric silsesquioxane in 24 parts of dimethylformamide, add the silicate mixture B, mix evenly, concentrate, dry, and calcine at 365 °C for 50 min to obtain the boron composite silicate; A method for preparing a low dielectric constant multilayer ceramic substrate includes the following steps: S1. Blend 100 parts of alumina, 6 parts of Y 2 O 3 , 12 parts of boron composite silicate, 5 parts of copper oxide, 4 parts of polyethylene glycol and 70 parts of ethanol, after dispersing evenly, add 8 parts of polyvinyl butyral, mix evenly to obtain a casting slurry; S2. Subject the casting slurry to defoaming, casting, drying, and stamping to obtain a green tape; S3. Punch the green tape, fill the holes, print a tungsten paste material with a thickness of 17 μm, stack and laminate 40 layers of green tapes, sinter in an air atmosphere at 1180 °C for 30 min, and cool to obtain a low dielectric constant multilayer ceramic substrate.

[0044] Example 8 The difference between this example and Example 7 is only that in this example, the preparation method of the boron composite silicate includes the following steps: A1. Disperse 0.25 part of p-hydroxymethylphenylboronic acid in 1.1 parts of absolute ethanol, add 25 parts of magnesium aluminum silicate and 5 parts of zirconium silicate, mix evenly, concentrate, and dry to obtain a silicate mixture A; A2. Blend the above silicate mixture A, 0.75 part of magnesium metaborate and 3 parts of water, ball-mill at a ball-milling speed of 300 rpm for 3.5 h, and dry to obtain a silicate mixture B; A3. Disperse 4 parts of cage-type polyhedral oligomeric silsesquioxane in 24 parts of dimethylformamide, add the silicate mixture B, mix evenly, concentrate, dry, and calcine at 365 °C for 50 min to obtain the boron composite silicate.

[0045] Example 9 The difference between this example and Example 7 is only that in this example, the preparation method of the boron composite silicate includes the following steps: A1. Disperse 1 part of p-hydroxymethylphenylboronic acid in 4.4 parts of absolute ethanol, add 25 parts of magnesium aluminum silicate and 5 parts of zirconium silicate, mix evenly, concentrate, and dry to obtain silicate mixture A; A2. Mix the above silicate mixture A, 3 parts of magnesium metaborate and 12 parts of water, ball-mill at a ball-milling speed of 300 rpm for 3.5 h, and dry to obtain silicate mixture B; A3. Disperse 4 parts of cage-like polyhedral oligomeric silsesquioxane in 24 parts of dimethylformamide, add silicate mixture B, mix evenly, concentrate, dry, and calcine at 365 °C for 50 min to obtain the boron composite silicate.

[0046] Example 10 The difference between this example and Example 7 is only that in this example, the preparation method of the boron composite silicate includes the following steps: A1. Disperse 0.5 part of p-hydroxymethylphenylboronic acid in 2.2 parts of absolute ethanol, add 25 parts of magnesium aluminum silicate and 5 parts of zirconium silicate, mix evenly, concentrate, and dry to obtain silicate mixture A; A2. Mix the above silicate mixture A, 1.5 parts of magnesium metaborate and 6 parts of water, ball-mill at a ball-milling speed of 300 rpm for 3.5 h, and dry to obtain silicate mixture B; A3. Disperse 4 parts of cage-like polyhedral oligomeric silsesquioxane in 24 parts of dimethylformamide, add silicate mixture B, mix evenly, concentrate, dry, and calcine at 365 °C for 50 min to obtain the boron composite silicate.

[0047] Example 11 The difference between this example and Example 7 is only that in this example, the preparation method of the boron composite silicate includes the following steps: A1. Disperse 0.8 part of p-hydroxymethylphenylboronic acid in 3.52 parts of absolute ethanol, add 25 parts of magnesium aluminum silicate and 5 parts of zirconium silicate, mix evenly, concentrate, and dry to obtain silicate mixture A; A2. Mix the above silicate mixture A, 2.4 parts of magnesium metaborate and 9.6 parts of water, ball-mill at a ball-milling speed of 300 rpm for 3.5 h, and dry to obtain silicate mixture B; A3. Disperse 4 parts of cage-like polyhedral oligomeric silsesquioxane in 24 parts of dimethylformamide, add silicate mixture B, mix evenly, concentrate, dry, and calcine at 365 °C for 50 min to obtain the boron composite silicate.

[0048] Comparative Example 1 The difference between this comparative example and Example 2 is only that in this comparative example, magnesium aluminum silicate is replaced with an equal amount of zirconium silicate.

[0049] Comparative Example 2 The difference between this comparative example and Example 2 is only that in this comparative example, zirconium silicate is replaced with an equal amount of magnesium aluminum silicate.

[0050] Comparative Example 3 The difference between this comparative example and Example 2 is only that in this comparative example, neither magnesium aluminum silicate nor zirconium silicate is added.

[0051] Experimental Example 1 The low dielectric constant multi-layer ceramic substrates prepared in Examples 1 to 6 and Comparative Examples 1 to 3 were tested for the flexural strength of the specimens according to the test method specified in GB / T 6569-2006 "Test Method for Flexural Strength of Fine Ceramics". Among them, the three-point bending test method was used, and the test results are shown in Table 1: Table 1 Flexural strength test results of Examples 1 to 6 and Comparative Examples 1 to 3

[0052] Compared with Comparative Examples 1 to 3, the flexural strength of the low dielectric constant multi-layer ceramic substrates prepared in Examples 1 to 6 is improved, indicating that when the silicate includes magnesium aluminum silicate and zirconium silicate, magnesium aluminum silicate and zirconium silicate have a synergistic effect, which can improve the flexural strength of the low dielectric constant multi-layer ceramic substrate, and the flexural strength can be increased to more than 468 MPa.

[0053] Experimental Example 2 The low dielectric constant multi-layer ceramic substrates prepared in Examples 6 to 11 were tested for dielectric constant according to the method in GB / T 5594.4-2015 "Test Methods for Properties of Structural Ceramic Materials for Electronic Components - Part 4: Test Methods for Dielectric Constant and Dissipation Factor". The test conditions were 10 GHz and 20 °C, and the test results are shown in Table 2: Table 2 Dielectric constant test results of Examples 6 to 11

[0054] Compared with Example 6, the dielectric constant of the multi-layer ceramic substrates prepared in Examples 7 to 11 is decreased, indicating that the boron composite silicate formed after calcination by compounding the silicate with a boron source and cage-like polyhedral oligomeric silsesquioxane can reduce the dielectric constant of the multi-layer ceramic substrate, and the dielectric constant can be reduced to less than 6.3.

[0055] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low dielectric constant multilayer ceramic substrate, characterized in that: The composition comprises the following components in parts by weight: 100 parts of aluminum oxide, 4-8 parts of sintering aid, 8-16 parts of silicate, 3-6 parts of copper oxide, 3-5 parts of dispersant, 6-12 parts of binder, 70 parts of solvent; The silicate comprises magnesium aluminum silicate and zirconium silicate in a weight ratio of 1.5 to 9:

1.

2. The low dielectric constant multilayer ceramic substrate according to claim 1, characterized in that: The weight ratio of the magnesium aluminum silicate to the zirconium silicate is 3-5:

1.

3. The low dielectric constant multilayer ceramic substrate according to claim 1, characterized in that: The silicate is a boron composite silicate, and the raw materials of the boron composite silicate include silicate, a boron source, and cage-type polysilsesquioxane.

4. The low dielectric constant multilayer ceramic substrate according to claim 3, characterized in that: The boron source includes an organic boron source and an inorganic boron source; The organic boron source includes phenylboric acid compounds; The inorganic boron source includes one or more of magnesium metaborate, lithium metaborate and sodium metaborate.

5. The low dielectric constant multilayer ceramic substrate according to claim 3, characterized in that: In the raw material of boron composite silicate, the weight ratio of the silicate, cage-type polysilsesquioxane and boron source is 30:4:1-4.

6. The low dielectric constant multilayer ceramic substrate according to claim 4, characterized in that: The weight ratio of the organic boron source to the inorganic boron source is 1:1-3.

7. The low dielectric constant multilayer ceramic substrate according to claim 4, characterized in that: The preparation method of the boron composite silicate comprises the following steps: A1, dispersing the organic boron source in anhydrous ethanol, adding the silicate, mixing evenly, concentrating, and drying to obtain a silicate mixture A; A2, blending the silicate mixture A, the inorganic boron source and water, ball milling, and drying to obtain a silicate mixture B; A3, dispersing the cage-type polysilsesquioxane in dimethylformamide, adding the silicate mixture B, mixing evenly, concentrating, drying, and calcining to obtain boron composite silicate.

8. The low dielectric constant multilayer ceramic substrate according to claim 1, characterized in that: The sintering aid includes one or more of Y2O3, CaF2, and La2O3; The dispersant includes one or two of tributyl phosphate and polyethylene glycol; The binder includes one or two of hydroxypropyl methylcellulose and polyvinyl butyral; The solvent includes one or both of ethanol and acetone.

9. A method for preparing a low dielectric constant multilayer ceramic substrate, for preparing the low dielectric constant multilayer ceramic substrate as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Blending the remaining components except the binder, after uniform dispersion, adding the binder, and mixing uniformly to obtain a casting slurry; S2, degassing, casting, drying and stamping the casting slurry to obtain a green porcelain tape; S3, punching, filling, printing, laminating, sintering and cooling the green ceramic tape to obtain the low dielectric constant multilayer ceramic substrate.

10. The method for preparing a low dielectric constant multilayer ceramic substrate according to claim 9, characterized in that: In step S3, when laminating, the number of layers is 30-45.

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