Zero-shrinkage low-temperature co-fired multilayer ceramic substrate and preparation method thereof

Abstract

The invention relates to the technical field of ceramic substrates, and provides a zero-shrinkage low-temperature co-fired multilayer ceramic substrate and a preparation method thereof. The zero-shrinkage low-temperature co-fired multilayer ceramic substrate comprises the following components in parts by weight: 60-70 parts of aluminum oxide, 20-30 parts of spinel, 2-4 parts of a sintering aid, 1-3 parts of a dispersant, 5-10 parts of a binder, 2-4 parts of a plasticizer and 70 parts of water, the spinel comprises magnesium aluminate spinel and zinc spinel in a weight ratio of (1: 9)-(9: 1); the magnesium aluminate spinel comprises magnesium aluminate spinel I and magnesium aluminate spinel II, and the contents of magnesium oxide in the magnesium aluminate spinel I and the magnesium aluminate spinel II are different. According to the technical scheme, the problem that the shrinkage rate of the low-temperature co-fired multilayer ceramic substrate is relatively high 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-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate and a preparation method thereof. Background Art

[0002] The co-firing process of multi-layer ceramic substrates is generally divided into high-temperature co-fired ceramic technology and low-temperature co-fired ceramic technology. Among them, high-temperature co-fired ceramic technology is a common co-firing process for traditional multi-layer ceramic substrates. It usually sinters ceramic materials such as alumina and aluminum nitride, combined with conductor materials with relatively high melting points (such as molybdenum, tungsten, etc.), at a high temperature above 1400°C. Although it has the advantage of high mechanical strength, the sintering temperature is relatively high, and it can only be co-fired with materials with high melting points and high resistances, which limits the selection of multi-layer ceramic substrate materials and has high energy consumption. With the continuous development of technology, some traditional ceramic materials for substrates and high-temperature sintering technologies can no longer meet the requirements of multi-layer ceramic substrates for low production energy consumption, high performance, and multi-functional design. At this time, low-temperature co-fired ceramic technology shows a rapid development trend.

[0003] However, when ordinary multi-layer ceramic substrates are sintered at low temperature, their inherent shrinkage will affect the assembly accuracy of the ceramic substrates. Especially in some high-performance systems, extremely small deformation of the multi-layer ceramic substrates will have a great impact on the performance of the ceramic substrates. Therefore, in the process of preparing low-temperature co-fired multi-layer ceramic substrates, it is extremely important to reasonably control the abnormal shrinkage rate during low-temperature sintering.

[0004] The research on zero-shrinkage low-temperature co-fired ceramic substrate materials began in the 1990s. The zero-shrinkage low-temperature co-fired ceramic substrate technology enables the prepared ceramic substrates to basically achieve zero shrinkage in the horizontal direction, while shrinkage still occurs in the vertical direction. The sintering methods of zero-shrinkage low-temperature co-fired ceramic substrates usually include non-pressure-assisted sintering method, pressure-assisted sintering method, and self-constrained sintering method. Among them, the self-constrained sintering method is the most commonly used. This method utilizes the characteristic of the substrate itself to inhibit the shrinkage in the plane direction during the sintering process, thereby achieving zero shrinkage of the low-temperature co-fired ceramic substrate in the horizontal direction. During the process of preparing zero-shrinkage low-temperature co-fired multi-layer ceramic substrates by the self-constrained sintering method, different sintering temperatures are usually adopted. The temperature of the intermediate layer is relatively low, and the sintering temperatures of the upper and lower layers are relatively high. By using the mutual restriction between the ceramic substrates at different sintering temperatures, the overall shrinkage of the multi-layer ceramic substrates is inhibited. However, although traditional low-temperature co-fired ceramic substrate materials can reduce the overall shrinkage rate of multi-layer ceramic substrates to a certain extent, the reduction degree is limited, which limits the application of low-temperature co-fired multi-layer ceramic substrates.

[0005] Based on this, developing a low-temperature co-fired multi-layer ceramic substrate that can significantly reduce its shrinkage rate is of great significance for expanding the application range of low-temperature co-fired multi-layer ceramic substrates. Summary of the Invention

[0006] The present invention provides a low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate and a preparation method thereof, which solves the problem of relatively high shrinkage rate of low-temperature co-fired multi-layer ceramic substrates in the related art.

[0007] The technical solution of the present invention is as follows: The present invention provides a low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate, comprising the following components in parts by weight: 60-70 parts of alumina, 20-30 parts of spinel, 2-4 parts of sintering aid, 1-3 parts of dispersant, 5-10 parts of binder, 2-4 parts of plasticizer, and 70 parts of water; The spinel includes magnesia-alumina spinel and zinc spinel with a weight ratio of 1:9-9:1; The magnesia-alumina spinel includes magnesia-alumina spinel I and magnesia-alumina spinel II, and the magnesia-alumina spinel I and magnesia-alumina spinel II have different contents of magnesium oxide.

[0008] As a further technical solution, the weight ratio of the magnesia-alumina spinel to the zinc spinel is 3-4:1.

[0009] As a further technical solution, the mass fraction of magnesium oxide in the magnesia-alumina spinel I is 21%-25%, and the mass fraction of magnesium oxide in the magnesia-alumina spinel II is 31%-35%.

[0010] As a further technical solution, the weight ratio of the magnesia-alumina spinel I to the magnesia-alumina spinel II is 1-3:1.

[0011] In the present invention, the magnesia-alumina spinel is divided into magnesia-alumina spinel I and magnesia-alumina spinel II with different magnesium oxide contents. When the mass fraction of magnesium oxide in the magnesia-alumina spinel I is 21%-25% and the mass fraction of magnesium oxide in the magnesia-alumina spinel II is 31%-35%, by adjusting the weight ratio of the magnesia-alumina spinel I to the magnesia-alumina spinel II to 1-3:1, the expansion and contraction inside the magnesia-alumina spinel can be made more coordinated. After acting with the zinc spinel, the shrinkage rate of the low-temperature co-fired multi-layer ceramic substrate can be further reduced, and the shrinkage rate of the X side in the horizontal direction of the low-temperature co-fired multi-layer ceramic substrate can be reduced to 0.071%-0.073%, and the Y side can be reduced to 0.067%-0.068%. When the weight ratio of the magnesia-alumina spinel I to the magnesia-alumina spinel II is outside the range of 1-3:1, the effect of reducing the shrinkage rate of the low-temperature co-fired multi-layer ceramic substrate is worse.

[0012] As a further technical solution, the particle size of the magnesia-alumina spinel is ≤100 μm; the particle size of the zinc spinel is 10-50 μm; the particle size of the alumina is 10-30 μm.

[0013] As a further technical solution, the spinel is a composite spinel containing hydroxyethylamine compounds.

[0014] As a further technical solution, the raw materials of the hydroxyethylamine compound composite spinel include spinel and hydroxyethylamine compound in a weight ratio of 48:2 to 9.

[0015] In the present invention, the spinel is compounded with a hydroxyethylamine compound. In the early stage, during the preparation of the tape-casting slurry, the interaction between the spinel and other organic components in the tape-casting slurry can be improved, and the wettability of the solvent and other components in the tape-casting slurry to the spinel can also be improved. During the tape-casting process, a green ceramic sheet with a more uniform and dense internal structure can be formed. In the later stage, through sintering treatment, a more dense low-temperature co-fired multi-layer ceramic substrate is formed, thereby improving its flexural strength.

[0016] As a further technical solution, the hydroxyethylamine compound includes one or two of N,N-dihydroxyethyl-p-methylaniline and N,N'-bis(2-hydroxyethyl)ethylenediamine.

[0017] As a further technical solution, the weight ratio of the spinel to the hydroxyethylamine compound is 48:3 to 7.

[0018] In the present invention, when the weight ratio of the spinel to the hydroxyethylamine compound is 48:3 to 7, the flexural strength of the low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate can be further improved.

[0019] As a further technical solution, the preparation method of the hydroxyethylamine compound composite spinel includes the following steps: A1. After ball-milling the spinel, a premix is obtained; A2. After dissolving the hydroxyethylamine compound in ethanol, a silane coupling agent and the premix are added, mixed evenly, concentrated, and dried to obtain the hydroxyethylamine compound composite spinel.

[0020] In the present invention, the silane coupling agent can be one of an amino silane coupling agent, a vinyl silane coupling agent, and an epoxy silane coupling agent. Preferably, it is an amino silane coupling agent. By adding the silane coupling agent, the combination of the spinel and the hydroxyethylamine compound can be promoted, and the composite treatment of the spinel with the hydroxyethylamine compound can be realized. Among them, the amino silane coupling agent can be, for example, γ-aminopropyltriethoxysilane or γ-aminopropyltrimethoxysilane. Preferably, it is γ-aminopropyltriethoxysilane.

[0021] As a further technical solution, the weight ratio of the spinel to the silane coupling agent is 48:1.5 to 3.5.

[0022] As a further technical solution, in step A1, during the ball milling, the rotation speed is 350 - 450 rpm and the time is 15 - 25 min.

[0023] In the present invention, the sintering aid includes one or more of B2O3, Bi2O3, and Li2O, and preferably B2O3, Bi2O3, and Li2O with a weight ratio of 2:2:1; The dispersant includes one or more of glyceryl trioleate, polyvinylpyrrolidone, and tributyl phosphate, and preferably tributyl phosphate; The binder includes one or more of polyvinyl butyral, carboxymethyl cellulose, hydroxyethyl cellulose, and water-soluble acrylic resin, and preferably polyvinyl butyral; The plasticizer includes one or more of dibutyl phthalate, dioctyl phthalate, and polyethylene glycol, and preferably dibutyl phthalate.

[0024] In the present invention, during the process of preparing the low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate, the sintering aid is essential. The addition of the sintering aid can reduce the sintering activation energy of the ceramic substrate material, lower the sintering temperature, and maintain the stability of each component during the sintering process, thereby improving the overall stability of the low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate. The sintering aid can be one or more of B2O3, Bi2O3, and Li2O. When the sintering aid is B2O3, Bi2O3, and Li2O with a weight ratio of 2:2:1, the stable regulation effect of the sintering aid can be fully exerted; The addition of the dispersant can effectively reduce the agglomeration of the powder and make the casting slurry have good stability. The dispersant can be one or more of glyceryl trioleate, polyvinylpyrrolidone, and tributyl phosphate. When the dispersant is tributyl phosphate, the dispersion effect is better; The binder can increase the bonding degree of each component in the casting slurry, provide basic strength for the green ceramic sheet after tape casting, and lay the foundation for the basic bending strength of the low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate after subsequent sintering treatment. The binder can be one or more of polyvinyl butyral, carboxymethyl cellulose, hydroxyethyl cellulose, and water-soluble acrylic resin. When the binder is polyvinyl butyral, the bonding effect is better; The addition of the plasticizer can reduce the glass transition temperature of the binder to a certain extent, thereby contributing to the forming of the casting slurry. The plasticizer can be one or more of dibutyl phthalate, dioctyl phthalate, and polyethylene glycol. When the plasticizer is dibutyl phthalate, the plasticizing effect is better.

[0025] The present invention also provides a method for preparing a low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate, which is used to prepare the above-mentioned low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate, and includes the following steps: S1. After uniformly mixing alumina, spinel, and sintering aids, add a dispersant, a binder, a plasticizer, and water, and ball-mill to obtain a casting slurry; S2. Degas, cast, and dry the casting slurry to obtain a green ceramic sheet; S3. After slicing, punching, via filling, printing, and laminating the green ceramic sheet, obtain a laminated green ceramic sheet; S4. Place a layer of high-temperature ceramic green ceramic sheet on each of the upper and lower surfaces of the laminated green ceramic sheet, laminate, debind, sinter, and cool, and then remove the high-temperature ceramic green ceramic sheet to obtain the low-temperature co-fired multilayer ceramic substrate with zero shrinkage rate.

[0026] As a further technical solution, the high-temperature ceramic green ceramic sheet is an aluminum nitride ceramic green ceramic sheet.

[0027] As a further technical solution, in step S1, the ball-milling includes a first ball-milling and a second ball-milling. The rotation speed of the first ball-milling is 150 - 250 rpm, and the time is 3 - 4 h; the rotation speed of the second ball-milling is 450 - 550 rpm, and the time is 1 - 2 h.

[0028] In the present invention, when preparing the casting slurry, it is divided into two ball-millings. The rotation speed of the first ball-milling is 150 - 250 rpm, the time is 3 - 4 h, the rotation speed of the second ball-milling is 450 - 550 rpm, and the time is 1 - 2 h. By reasonably controlling the rotation speed and time of the two ball-millings, a large amount of air bubbles mixed into the casting slurry can be reduced to a certain extent. Combined with subsequent degassing treatment, a uniform and stable casting slurry can be formed.

[0029] As a further technical solution, in step S2, the degassing is vacuum degassing, the vacuum degree of the vacuum degassing is 0.3 - 0.4 MPa, and the time is 15 - 25 min.

[0030] As a further technical solution, in step S3, the number of laminated layers is 30 - 35.

[0031] As a further technical solution, in step S4, during the lamination, the temperature is 50 - 60 °C, the pressure is 7 - 9 MPa, and the time is 1 - 2 h.

[0032] As a further technical solution, in step S4, the debinding time is 45 - 55 min.

[0033] As a further technical solution, in step S4, the sintering includes a first sintering and a second sintering. The temperature of the first sintering is 640 - 680 °C, and the time is 25 - 35 min; the temperature of the second sintering is 780 - 810 °C, and the time is 8 - 15 min.

[0034] The working principle and beneficial effects of the present invention are as follows: 1. In the present invention, alumina itself has certain heat dissipation performance and good high-temperature resistance. As the main framework material of the low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate, it can provide basic thermal stability and thermal conductivity for the ceramic substrate. Spinel, sintering aid, dispersant, binder, and plasticizer as auxiliary materials act on alumina to prepare a low-temperature co-fired multi-layer ceramic substrate with uniform and dense internal structure and zero shrinkage rate.

[0035] 2. In the present invention, the spinel includes magnesium aluminate spinel and zinc spinel. The combined use of magnesium aluminate spinel and zinc spinel can reduce the thermal expansion behavior of the low-temperature co-fired multi-layer ceramic substrate. During the later sintering process, magnesium aluminate spinel and zinc spinel can reduce the shrinkage of the green ceramic sheet caused by thermal stress. Moreover, the combined use of magnesium aluminate spinel and zinc spinel can, to a certain extent, reduce the horizontal migration between layers, making the dimensional change of the low-temperature co-fired multi-layer ceramic substrate more stable, thereby overall reducing the shrinkage rate of the low-temperature co-fired multi-layer ceramic substrate to basically reach the state of zero shrinkage rate. In addition, when the weight ratio of magnesium aluminate spinel to zinc spinel is 1:9 to 9:1, the effect of reducing the shrinkage rate of the low-temperature co-fired multi-layer ceramic substrate is good.

[0036] 3. In the present invention, the compound use of magnesium aluminate spinel I and magnesium aluminate spinel II with different magnesium oxide contents can make the expansion and contraction inside the magnesium aluminate spinel more coordinated, and can reduce the shrinkage rate of the low-temperature co-fired multi-layer ceramic substrate after acting with zinc spinel. Specific Embodiments

[0037] Next, 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 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 protection of the present invention.

[0038] In the following examples and comparative examples, the particle size of alumina is 20 μm; the particle size of zinc spinel is 15 μm, purchased from Wuhan Pulov Bio-Tech Co., Ltd.; the model of magnesium aluminate spinel I is MA-75, the particle size is 50 μm, and the mass fraction of magnesium oxide is 21% - 25%; the model of magnesium aluminate spinel II is MA-65, the particle size is 50 μm, and the mass fraction of magnesium oxide is 31% - 35%; the model of polyvinyl butyral is TB-20.

[0039] Example 1 S1. After uniformly mixing 60 parts of alumina, 20 parts of spinel, 0.8 part of B2O3, 0.8 part of Bi2O3 and 0.4 part of Li2O, add 1 part of tributyl phosphate, 5 parts of polyvinyl butyral, 2 parts of dibutyl phthalate and 70 parts of water. Ball mill at 150 rpm for 4 h and then at 450 rpm for 2 h to obtain a casting slurry; among them, the spinel includes 1.6 parts of magnesium-aluminum spinel I, 0.4 part of magnesium-aluminum spinel II and 18 parts of zinc spinel; S2. Vacuum degas the casting slurry under a vacuum of 0.3 MPa for 25 min, then cast and dry to obtain a green ceramic sheet; S3. Cut, punch, fill through holes and print the green ceramic sheet. After laminating 30 layers of green ceramic sheets, obtain the laminated green ceramic sheet; S4. Place one layer of aluminum nitride ceramic green ceramic sheet on each of the upper and lower surfaces of the laminated green ceramic sheet. After laminating at 50 °C and 7 MPa for 2 h, keep warm and degum for 55 min, then sinter at 640 °C for 35 min and at 780 °C for 15 min, cool, and remove the high-temperature ceramic green ceramic sheet to obtain a low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate.

[0040] Example 2 S1. After uniformly mixing 65 parts of alumina, 24 parts of spinel, 1.2 parts of B2O3, 1.2 parts of Bi2O3 and 0.6 part of Li2O, add 2 parts of tributyl phosphate, 8 parts of polyvinyl butyral, 3 parts of dibutyl phthalate and 70 parts of water. Ball mill at 200 rpm for 3.5 h and then at 500 rpm for 1.5 h to obtain a casting slurry; among them, the spinel includes 12.8 parts of magnesium-aluminum spinel I, 3.2 parts of magnesium-aluminum spinel II and 8 parts of zinc spinel; S2. Vacuum degas the casting slurry under a vacuum of 0.4 MPa for 20 min, then cast and dry to obtain a green ceramic sheet; S3. Cut, punch, fill through holes and print the green ceramic sheet. After laminating 35 layers of green ceramic sheets, obtain the laminated green ceramic sheet; S4. Place one layer of aluminum nitride ceramic green ceramic sheet on each of the upper and lower surfaces of the laminated green ceramic sheet. After laminating at 55 °C and 8 MPa for 1.5 h, keep warm and degum for 50 min, then sinter at 660 °C for 30 min and at 790 °C for 10 min, cool, and remove the high-temperature ceramic green ceramic sheet to obtain a low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate.

[0041] Example 3 S1. After uniformly mixing 70 parts of alumina, 30 parts of spinel, 1.6 parts of B2O3, 1.6 parts of Bi2O3 and 0.8 part of Li2O, add 3 parts of tributyl phosphate, 10 parts of polyvinyl butyral, 4 parts of dibutyl phthalate and 70 parts of water, ball mill at 250 rpm for 3 h, and then ball mill at 550 rpm for 1 h to obtain a casting slurry; among them, the spinel includes 21.6 parts of magnesium aluminate spinel I, 5.4 parts of magnesium aluminate spinel II and 3 parts of zinc spinel; S2. Vacuum degas the casting slurry at a vacuum degree of 0.4 MPa for 15 min, cast and dry to obtain a green ceramic sheet; S3. Slice, punch, fill through holes and print the green ceramic sheet. After laminating 35 layers of green ceramic sheets, obtain the laminated green ceramic sheet; S4. Place a layer of aluminum nitride ceramic green ceramic sheet on each of the upper and lower surfaces of the laminated green ceramic sheet, perform lamination treatment at 60 °C and 9 MPa for 1 h, keep warm and degum for 45 min, then sinter at 680 °C for 25 min, sinter at 810 °C for 8 min, cool, and remove the high-temperature ceramic green ceramic sheet to obtain a low-temperature co-fired multi-layer ceramic substrate with zero shrinkage rate.

[0042] Example 4 The difference between this example and Example 2 is only that in this example, the spinel includes 16.8 parts of magnesium aluminate spinel I, 4.2 parts of magnesium aluminate spinel II and 3 parts of zinc spinel.

[0043] Example 5 The difference between this example and Example 2 is only that in this example, the spinel includes 15.36 parts of magnesium aluminate spinel I, 3.84 parts of magnesium aluminate spinel II and 4.8 parts of zinc spinel.

[0044] Example 6 The difference between this example and Example 2 is only that in this example, the spinel includes 14.4 parts of magnesium aluminate spinel I, 3.6 parts of magnesium aluminate spinel II and 6 parts of zinc spinel.

[0045] Example 7 The difference between this example and Example 6 is only that in this example, the added magnesium aluminate spinel I is 7 parts and the added magnesium aluminate spinel II is 11 parts.

[0046] Example 8 The difference between this example and Example 6 is only that in this example, the added magnesium aluminate spinel I is 9 parts and the added magnesium aluminate spinel II is 9 parts.

[0047] Example 9 The difference between this example and Example 6 is only that in this example, the added magnesium aluminate spinel I is 13.5 parts and the added magnesium aluminate spinel II is 4.5 parts.

[0048] Example 10 The difference between this example and Example 9 is only that in this example, the spinel is a composite spinel containing hydroxyethylamine compounds; The preparation method of the composite spinel containing hydroxyethylamine compounds includes the following steps: A1. Grind 48 parts of spinel (27 parts of magnesium-aluminum spinel I, 9 parts of magnesium-aluminum spinel II, and 12 parts of zinc spinel) at 400 rpm for 20 minutes to obtain a premix; A2. Dissolve 2 parts of N,N-dihydroxyethyl-p-methylaniline in 55 parts of ethanol, then add 2 parts of γ-aminopropyltriethoxysilane and the above premix, mix evenly, concentrate, and dry to obtain a composite spinel containing hydroxyethylamine compounds; A preparation method of a zero-shrinkage low-temperature co-fired multi-layer ceramic substrate for preparing a zero-shrinkage low-temperature co-fired multi-layer ceramic substrate includes the following steps: S1. Mix 65 parts of alumina, 24 parts of the above composite spinel containing hydroxyethylamine compounds, 1.2 parts of B2O3, 1.2 parts of Bi2O3, and 0.6 part of Li2O evenly, then add 2 parts of tributyl phosphate, 8 parts of polyvinyl butyral, 3 parts of dibutyl phthalate, and 70 parts of water, grind at 200 rpm for 3.5 hours, and then grind at 500 rpm for 1.5 hours to obtain a casting slurry; S2. Vacuum degas the casting slurry at a vacuum degree of 0.4 MPa for 20 minutes, cast and form, and dry to obtain a green ceramic sheet; S3. Cut, punch holes, fill through holes, and print the green ceramic sheet. After laminating 35 layers of green ceramic sheets, obtain a laminated green ceramic sheet; S4. Place a layer of aluminum nitride ceramic green ceramic sheet on each of the upper and lower surfaces of the laminated green ceramic sheet, perform lamination treatment at 55 °C and 8 MPa for 1.5 hours, keep warm and degum for 50 minutes, then sinter at 660 °C for 30 minutes, sinter at 790 °C for 10 minutes, cool, and remove the high-temperature ceramic green ceramic sheet to obtain a zero-shrinkage low-temperature co-fired multi-layer ceramic substrate.

[0049] Example 11 The difference between this example and Example 10 is only that in the process of preparing the composite spinel containing hydroxyethylamine compounds in this example, 9 parts of N,N-dihydroxyethyl-p-methylaniline are added.

[0050] Example 12 The difference between this example and Example 10 is only that in the process of preparing the composite spinel containing hydroxyethylamine compounds in this example, 3 parts of N,N-dihydroxyethyl-p-methylaniline are added.

[0051] Example 13 The difference between this example and Example 10 is only that in the process of preparing the composite spinel containing hydroxyethylamine compounds in this example, 7 parts of N,N-dihydroxyethyl-p-methylaniline are added.

[0052] Comparative Example 1 The difference between this comparative example and Example 2 is only that in this comparative example, magnesium-aluminum spinel I is replaced with an equal amount of magnesium-aluminum spinel II.

[0053] Comparative Example 2 The difference between this comparative example and Example 2 is only that in this comparative example, magnesium-aluminum spinel II is replaced with an equal amount of magnesium-aluminum spinel I.

[0054] Comparative Example 3 The difference between this comparative example and Example 2 is only that in this comparative example, neither magnesium-aluminum spinel I nor magnesium-aluminum spinel II is added.

[0055] Experimental Example 1 The shrinkage rates of the X and Y sides of the zero-shrinkage low-temperature co-fired multi-layer ceramic substrates prepared in Examples 1 to 9 and Comparative Examples 1 to 3 were respectively tested, and the shrinkage rate was calculated according to the following formula. Among them, the shrinkage rate of the X side (%) = (the length of the X side of the green ceramic sheet before lamination - the length of the X side of the low-temperature co-fired multi-layer ceramic substrate after sintering) / the length of the X side of the green ceramic sheet before lamination × 100%, and the shrinkage rate of the Y side (%) = (the length of the Y side of the green ceramic sheet before lamination - the length of the Y side of the low-temperature co-fired multi-layer ceramic substrate after sintering) / the length of the Y side of the green ceramic sheet before lamination × 100%; among them, the length of the X side of the green ceramic sheet before lamination is 80 mm, and the length of the Y side of the green ceramic sheet before lamination is 80 mm; the test results are shown in Table 1: Table 1 Shrinkage rate test results of Examples 1 to 9 and Comparative Examples 1 to 3

[0056] As can be seen from Table 1, compared with Comparative Examples 1 to 3, the shrinkage rates of the X and Y sides of the zero-shrinkage low-temperature co-fired multi-layer ceramic substrates prepared in Examples 1 to 9 are reduced, indicating that when the magnesium-aluminum spinel includes magnesium-aluminum spinel I and magnesium-aluminum spinel II, by using the two in combination, the shrinkage rate of the zero-shrinkage low-temperature co-fired multi-layer ceramic substrate can be reduced, so that the shrinkage rate of the X side is at least reduced to 0.094%, and the shrinkage rate of the Y side is at least reduced to 0.089%, basically meeting the requirement of zero shrinkage rate.

[0057] Experimental Example 2 The zero-shrinkage low-temperature co-fired multi-layer ceramic substrates prepared in Examples 9 to 13 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 adopted; the test results are shown in Table 2: Table 2 Flexural Strength Test Results of Examples 9 to 13

[0058] As can be seen from Table 2, compared with Example 9, the flexural strength of the zero-shrinkage low-temperature co-fired multi-layer ceramic substrates prepared in Examples 10 to 13 was significantly improved, indicating that the composite treatment of spinel with hydroxyethylamine compounds can improve the flexural strength of the zero-shrinkage low-temperature co-fired multi-layer ceramic substrates.

[0059] 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 zero-shrinkage low-temperature co-fired multi-layer ceramic substrate, characterized in that: The composition comprises the following components in parts by weight: 60-70 parts of alumina, 20-30 parts of spinel, 2-4 parts of sintering aid, 1-3 parts of dispersant, 5-10 parts of binder, 2-4 parts of plasticizer, 70 parts of water; The spinel comprises magnesium aluminum spinel and zinc spinel in a weight ratio of 1:9 to 9:1; The magnesium-aluminum spinel includes magnesium-aluminum spinel I and magnesium-aluminum spinel II, and the magnesium-aluminum spinel I and magnesium-aluminum spinel II have different contents of magnesium oxide.

2. The zero-shrinkage low-temperature co-fired multi-layer ceramic substrate according to claim 1, characterized in that: The mass fraction of magnesium oxide in the magnesium-aluminum spinel I is 21% to 25%, and the mass fraction of magnesium oxide in the magnesium-aluminum spinel II is 31% to 35%.

3. The zero-shrinkage low-temperature co-fired multi-layer ceramic substrate according to claim 1, characterized in that: The weight ratio of the magnesium-aluminum spinel I to the magnesium-aluminum spinel II is 1-3:

1.

4. The zero-shrinkage low-temperature co-fired multi-layer ceramic substrate according to claim 3, characterized in that: The spinel is a composite spinel containing hydroxyethylamine compounds.

5. The zero-shrinkage low-temperature co-fired multi-layer ceramic substrate according to claim 4, characterized in that: The raw materials of the composite spinel containing hydroxyethylamine compounds include spinel and hydroxyethylamine compounds in a weight ratio of 48:2-9.

6. The zero-shrinkage low-temperature co-fired multi-layer ceramic substrate according to claim 5, characterized in that: The hydroxyethylamine-containing compound includes one or two of N,N-dihydroxyethyl-p-methylaniline and N,N'-bis(2-hydroxyethyl)ethylenediamine.

7. The zero-shrinkage low-temperature co-fired multi-layer ceramic substrate according to claim 5, characterized in that: The weight ratio of the spinel to the hydroxyethylamine-containing compound is 48:3-7.

8. The zero-shrinkage low-temperature co-fired multi-layer ceramic substrate according to claim 1, characterized in that: The sintering aid includes one or more of B2O3, Bi2O3, Li2O; and / or The dispersant comprises one or more of triolein, polyvinyl pyrrolidone, and tributyl phosphate; and / or The binder includes one or more of polyvinyl butyral, carboxymethyl cellulose, hydroxyethyl cellulose, and water-soluble acrylic resin; and / or The plasticizer includes one or more of dibutyl phthalate, dioctyl phthalate, and polyethylene glycol.

9. A method for preparing a zero-shrinkage low-temperature co-fired multi-layer ceramic substrate, used for preparing a zero-shrinkage low-temperature co-fired multi-layer ceramic substrate as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: S1, after mixing alumina, spinel and sintering aid evenly, add dispersant, binder, plasticizer and water, and ball mill to obtain casting slurry; S2, degassing, tape casting and drying the casting slurry to obtain a green ceramic sheet; S3, slicing, punching, through-hole filling, printing, and laminating the raw ceramic sheets to obtain laminated raw ceramic sheets; S4, placing a layer of high-temperature ceramic green ceramic sheet on the upper and lower surfaces of the laminated green ceramic sheet respectively, laminating, debinding, sintering, cooling, and then removing the high-temperature ceramic green ceramic sheet to obtain the zero-shrinkage low-temperature co-fired multi-layer ceramic substrate.

10. The method for preparing a zero-shrinkage low-temperature co-fired multi-layer ceramic substrate according to claim 9, characterized in that: The high temperature ceramic green sheet is an aluminum nitride ceramic green sheet.

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