Alumina ceramic substrate material as well as preparation method and application thereof

Abstract

The invention discloses an alumina ceramic substrate material and a preparation method and application thereof, and relates to the technical field of functional ceramics, the alumina ceramic substrate material comprises, by mass, 99.2-99.6 wt% of a modifier and 0.1-0.4 wt% of a glass phase cooling agent, and the alumina ceramic substrate material comprises, by mass, 99.2-99.6 wt% of the modifier, 0.2-0.4 wt% of the modifier and 0.1-0.4 wt% of the glass phase cooling agent. The ceramic substrate material is small in dielectric property fluctuation, the characterization index-standard deviation S of the degree of data deviation from an average value is within + / -5%, the characterization index-variable coefficient CV of the data fluctuation degree is smaller than 15%, and the ceramic substrate material has the characteristic of high strength.

Description

Technical Field

[0001] This invention relates to the field of functional ceramics technology, specifically to an alumina ceramic substrate material, its preparation method, and its application. Background Technology

[0002] Ceramic substrates possess excellent electrical properties, good high-frequency characteristics, high thermal conductivity, excellent insulation, high stability, chemical inertness, high mechanical strength, and precision processing adaptability. They can be used in IGBT modules, chip packaging, 5G base station RF devices, aerospace engine sensors, high-frequency communication millimeter-wave circuits, and other fields. Their technology continues to drive electronic devices toward high frequency, high power, and high integration, and demand in fields such as new energy, 5G / 6G communication, and aerospace will continue to grow.

[0003] Modern high-end manufacturing places higher demands on integration, reliability, and efficiency, driving the need for large-size ceramic substrates. With the increasing complexity of 5G communications, chips, and power modules, large-size substrates can integrate more functional units (such as chips, resistors, and capacitors), support high-density wiring (linewidth < 50μm), avoid impedance mismatch at interfaces between different substrates, and reduce signal delay and loss caused by external connections (e.g., reducing insertion loss by 30%). This is especially important for superconducting quantum chips, which require large-size, ultra-flat Al2O3 substrates to support the low-temperature stable operation of thousands of qubits. The high integration and multifunctionality of electronic devices necessitate that substrate materials, in addition to excellent electrical and thermal matching properties, must also possess higher strength, chemical stability, and impact resistance. Alumina ceramic substrates, as the ceramic material with the best overall performance in the electronics industry, have the highest application maturity and low cost, accounting for 90% of all ceramic substrates, making them more suitable for preparing high-strength, large-size ceramic substrates for commercial applications.

[0004] High-strength, large-size ceramic substrates place high demands on material preparation methods, subsequent processing, and performance consistency. During preparation, powder agglomeration and component segregation lead to stress differences between the edge and center of the cast film, causing microcracks; uneven density after firing results in delamination, warping, unevenness, and cracking after sintering; uneven adhesion during post-processing; and excessive fluctuations in dielectric properties lead to localized overheating, reduced device lifespan, signal deviation, dispersed load-bearing capacity, and decreased safety factor. Summary of the Invention

[0005] Given the problem of excessive fluctuations in dielectric properties of current ceramic substrates, the present invention aims to provide an alumina ceramic substrate material, its preparation method, and its application. This ceramic substrate material exhibits relatively small fluctuations in dielectric properties, with the standard deviation S, a characterizing index of the degree of deviation from the average value, within ±5%, and the coefficient of variation CV, a characterizing index of the degree of data fluctuation, <15%. Furthermore, it possesses high strength characteristics.

[0006] This invention is achieved through the following technical solution: In a first aspect, the present invention provides an alumina ceramic substrate material, which is composed of... It consists of modifiers and glass phase cooling agents, comprising 99.2~99.6 wt% by mass. 0.2~0.4wt% modifier, 0.1~0.4wt% glass phase cooling agent.

[0007] Furthermore, the modifier, by mass percentage, comprises 0.03wt%~0.15wt% of La2O3, 0.01wt%~0.05wt% of Y2O3, 0.01wt%~0.03wt% of ZnO, 0.05wt%~0.18wt% of ZrO2, 0.01wt%~0.05wt% of Sm2O3, and 0.01wt%~0.028wt% of MgO.

[0008] The alumina ceramic substrate material of the present invention is based on Using La2O3, Y2O3, ZnO, ZrO2, Sm2O3, and MgO as the main raw materials, the material is modified by doping. La2O3, Y2O3, Sm2O3, and MgO inhibit grain growth, refine grains, and reduce dielectric loss. ZrO2 toughens the ceramic body, improving fracture toughness through a synergistic effect of phase transformation toughening, microcrack toughening, and residual stress toughening. Y2O3 stabilizes ZrO2, contributing to phase transformation toughening, while MgO partially stabilizes and provides microcrack toughening. ZnO improves wettability, encapsulates ceramic particles in the liquid phase, promotes particle rearrangement, and accelerates sintering. The added glass cooling agent promotes liquid-phase sintering, lowers the sintering temperature, accelerates material diffusion, reduces porosity, and inhibits abnormal grain growth. This alumina ceramic substrate material exhibits minimal dielectric property fluctuations and low dielectric loss, enabling the fabrication of large-size ceramic substrates with high strength and a flat, non-warping finish.

[0009] Furthermore, the glass cooling agent is Ca-Mg-B-Si glass.

[0010] Furthermore, the glass cooling agent comprises, by mass percentage, 20wt%~30wt% Ca(OCH2CH3)2, 5wt%~15wt% Mg(OCH3)2, 30wt%~45wt% Si(OCH2CH3)4, and 10wt%~45wt% B(OCH2CH3)3.

[0011] Secondly, this application provides a method for preparing an alumina ceramic substrate material, comprising the following steps: Will Slowly add anhydrous ethanol, stir evenly, ultrasonically disperse at 30°C for 0.5 h, add 0.8 wt% polyvinylpyrrolidone (PVP) and stir for 20 min, adjust the pH value to strong alkalinity using ammonia water (adjust the pH value to about 10) to obtain an alumina ethanol suspension. Adopted and The same method was used to treat La2O3, Y2O3, ZnO, ZrO2, Sm2O3, and MgO to obtain lanthanum oxide ethanol suspension, yttrium oxide ethanol suspension, zinc oxide ethanol suspension, zirconium dioxide ethanol suspension, samarium oxide ethanol suspension, and magnesium oxide ethanol suspension. When necessary, a certain amount of hydroxyethyl cellulose (HEC) can be added to inhibit sedimentation; Tetraethyl orthosilicate was dissolved in anhydrous ethanol, and then calcium ethoxide, magnesium methoxide and triethyl borate solution were added in sequence. The mixture was stirred for 1 hour to obtain a glass sol. Lanthanum oxide ethanol suspension, yttrium oxide ethanol suspension, zinc oxide ethanol suspension, zirconium dioxide ethanol suspension, samarium oxide ethanol suspension, and magnesium oxide ethanol suspension were added to alumina ethanol suspension, followed by glass sol. The mixture was stirred until homogeneous, ultrasonically dispersed at 30°C for 1-3 hours, and then aged at room temperature for 24 hours. The mixture was then dried at 80°C and sieved (through a 320-mesh sieve) to obtain alumina ceramic substrate material. Organic solvent, ceramic material, binder, and dispersant are added sequentially to a high-speed dispersing mill in a mass percentage ratio of 54:35:8:3 to obtain ceramic slurry. The ceramic slurry was used to prepare ceramic films using a thick film casting machine; The ceramic films are stacked to form a green body, which is then sintered to obtain an alumina ceramic substrate material.

[0012] The dispersant is dimethylethylene diammonium tetraacetate (DTPMP) + citric acid + tert-butylphenyl phosphate (TBP) in a mass percentage of 35:45:20; the adhesive includes polyvinyl butyral; the organic solvent is a mixture of anhydrous ethanol and toluene, and the mass ratio of anhydrous ethanol to toluene is 1:(1~5).

[0013] Among them, vacuum degassing controls the viscosity of the slurry to 10000cp~15000cp; the ceramic slurry is prepared into a ceramic film with a thickness of (160±5)μm using a thick film casting machine; the ceramic film is stacked and cut into green blanks in a certain way, and sintered at (1420±50)℃ to obtain alumina ceramic substrate material.

[0014] Furthermore, when preparing the ceramic slurry, the grinding cycle is carried out according to the ratio of material:ball:solution = 1:5:(1.5~3).

[0015] Furthermore, the sanding cycle is repeated 10 to 30 times, each time for 8 to 20 minutes.

[0016] Furthermore, the organic solvent is a mixture of anhydrous ethanol and toluene, wherein the mass ratio of anhydrous ethanol to toluene is 1:(1~5).

[0017] Furthermore, the adhesive comprises polyvinyl butyral.

[0018] Thirdly, this application provides a ceramic substrate, including the above-mentioned alumina ceramic substrate material or the alumina ceramic substrate material prepared by the above-mentioned preparation method.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The alumina (purity ≥ 99.2%) ceramic substrate material in this invention meets the following indicators: dielectric constant The dielectric loss is 9.9 ± 0.2 (1MHz, 1.9GHz, 5.1GHz, 10GHz, 15GHz), tan φ. δ ≤0.0003 (1MHz, 1.9GHz, 5.1GHz, 10GHz, 15GHz) can be used to prepare large-size ceramic substrates (≥4 inches).

[0020] (2) The dielectric properties of the alumina ceramic substrate material in this invention exhibit small fluctuations, and the dielectric constant varies at different frequencies (1MHz, 1.9GHz, 5.1GHz, 10GHz, 15GHz). S The dielectric losses were 3.6%, 3.1%, 3.9%, 3.4%, and 3.3%, respectively. S The values ​​are 0.0006%, 0.0012%, 0.0009%, 0.0009%, and 0.0008%, respectively; the CV values ​​of the dielectric constant are 0.4%, 0.3%, 0.4%, 0.3%, and 0.3%, respectively; and the CV values ​​of the dielectric loss are 6.8%, 9.7%, 5.5%, 4.2%, and 3.3%, respectively.

[0021] (3) The alumina ceramic substrate material in this invention enhances the powder dispersion effect by coating alumina particles with glass sol, and the dense sintering method enables the prepared alumina ceramic substrate material to meet the requirements of high strength and flexural strength. σ min ≥550MPa, σ aver ≥750Mpa.

[0022] (4) By controlling the sintering curve and sintering atmosphere, the alumina ceramic substrate material prepared in this invention can be made into a 4-inch ceramic substrate with a flat and non-warped product (warping degree < 0.3%) and a roughness distribution of (40~60) nm in the sintered state. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the placement of samples prepared in the embodiments and comparative examples of the present invention during sintering, which considers the case of placing only one product in a single layer. Figure 2 This is a schematic diagram of the sintering curves of the samples prepared in the embodiments and comparative examples of the present invention during sintering; Figure 3 The dielectric constant of the alumina ceramic substrate material prepared in Example 3 of this invention at different frequencies. ε and dielectric loss tan δ The value of and the difference from the mean; Figure 4 The figures show the measured bending strength results of the alumina ceramic substrate materials prepared in Examples 1, 3, Comparative Examples 1 and 4 of this invention. Figure 5 The image shows the roughness test results at different points of the alumina ceramic substrate material prepared in Example 3 of this invention; Figure 6 This is a physical image of the alumina ceramic substrate material prepared in Example 3 of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. The illustrative embodiments and descriptions of this invention are only used to explain this invention and are not intended to limit this invention.

[0026] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known materials or methods have not been specifically described in order to avoid obscuring the invention.

[0027] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described herein, as well as the features of those different embodiments or examples.

[0028] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0029] Example 1 This embodiment provides a method for preparing an alumina ceramic substrate material, the formulation of which is: 99.2 wt% Al2O3, 0.15 wt% La2O3, 0.05 wt% Y2O3, 0.03 wt% ZnO, 0.1 wt% ZrO2, 0.05 wt% Sm2O3, 0.02 wt% MgO, and 0.4 wt% glass cooling agent.

[0030] The specific preparation method is as follows: S1. Slowly add Al2O3 to anhydrous ethanol at a mass ratio of 1:1. Stir until homogeneous, and then ultrasonically disperse at 30°C for 0.5 h. Add 0.8 wt% polyvinylpyrrolidone (PVP), stir for 20 min, and then add ammonia to adjust the pH to 10 to obtain an alumina ethanol suspension.

[0031] S2. Treat other oxides in the additives using the same steps, and add 0.5% hydroxyethyl cellulose (HEC) if necessary to inhibit sedimentation; S3. Add tetraethyl orthosilicate (TEOS) and an appropriate amount of anhydrous ethanol and stir until fully dissolved. Add anhydrous calcium ethanol, magnesium methoxide and triethyl borate in sequence according to the mass percentage of CaO:MgO:SiO2:B2O3 of 20:10:30:40. Stir for 1 hour to obtain glass sol. S4. Lanthanum oxide ethanol suspension, yttrium oxide ethanol suspension, zinc oxide ethanol suspension, zirconium dioxide ethanol suspension, samarium oxide ethanol suspension, and magnesium oxide ethanol suspension were sequentially added to alumina ethanol suspension. Then, 0.4 wt% glass sol of glass phase additive was added, stirred evenly, ultrasonically dispersed at 30°C for 2 hours, allowed to stand at room temperature for 24 hours, dried at 80°C and sieved (320 mesh sieve) to obtain alumina ceramic substrate material. S5. Add ceramic material, polyvinyl butyral, and dispersant to the organic solvent and perform sand milling. The ratio of material:ball:solution is 1:5:2. Perform sand milling 20 times, 15 minutes each time, to obtain ceramic slurry.

[0032] S6. The ceramic slurry is used to prepare a 160μm ceramic film using a thick film casting machine; vacuum degassing is used to control the viscosity of the slurry at 13000cp.

[0033] S7. The ceramic films are stacked to form a green body and sintered. The sintering curves are shown in Table 2 to obtain alumina ceramic substrate material.

[0034] Example 2 This embodiment provides a method for preparing an alumina ceramic substrate material. Unlike Embodiment 1, the formulation composition and dosage in this embodiment are different. The formulation composition is: 99.6 wt% Al2O3, 0.09 wt% La2O3, 0.03 wt% Y2O3, 0.03 wt% ZnO, 0.1 wt% ZrO2, 0.03 wt% Sm2O3, 0.02 wt% MgO, and 0.1 wt% glass cooling agent.

[0035] The specific preparation method is as follows: S1. Slowly add Al2O3 to anhydrous ethanol at a mass ratio of 1:1. Stir until homogeneous, and then ultrasonically disperse at 30°C for 0.5 h. Add 0.8 wt% polyvinylpyrrolidone (PVP), stir for 20 min, and then add ammonia to adjust the pH to 10 to obtain an alumina ethanol suspension.

[0036] S2. Treat other oxides in the additives using the same steps, and add 0.5% hydroxyethyl cellulose (HEC) if necessary to inhibit sedimentation; S3. Add tetraethyl orthosilicate (TEOS) and an appropriate amount of anhydrous ethanol and stir until fully dissolved. Add calcium ethanol, magnesium methoxide and triethyl borate in sequence according to the mass percentage of CaO:MgO:SiO2:B2O3 of 20:10:30:40, and stir for 1 hour to obtain glass sol. S4. Lanthanum oxide ethanol suspension, yttrium oxide ethanol suspension, zinc oxide ethanol suspension, zirconium dioxide ethanol suspension, samarium oxide ethanol suspension, and magnesium oxide ethanol suspension were sequentially added to alumina ethanol suspension. Then, 0.4 wt% glass sol of glass phase additive was added, stirred evenly, ultrasonically dispersed at 30°C for 2 hours, allowed to stand at room temperature for 24 hours, dried at 80°C and sieved (320 mesh sieve) to obtain alumina ceramic substrate material. S5. Add ceramic material, polyvinyl butyral, and dispersant to the organic solvent and perform sand milling. The ratio of material:ball:solution is 1:5:3. Perform sand milling cycles 30 times, each for 8 minutes, to obtain ceramic slurry.

[0037] S6. Prepare a 155μm ceramic film from the ceramic slurry using a thick film casting machine; control the viscosity of the slurry to 10000cp by vacuum degassing.

[0038] S7. The ceramic films are stacked to form a green body and sintered. The sintering curves are shown in Table 2 to obtain alumina ceramic substrate material.

[0039] Example 3 This embodiment provides a method for preparing an alumina ceramic substrate material. Unlike Embodiment 1, the formulation composition and dosage in this embodiment are different. The formulation composition is as follows: 99.236 wt% Al2O3, 0.12 wt% La2O3, 0.04 wt% Y2O3, 0.012 wt% ZnO, 0.13 wt% ZrO2, 0.045 wt% Sm2O3, 0.017 wt% MgO, and 0.4 wt% glass cooling agent.

[0040] The specific preparation method is as follows: S1. Slowly add Al2O3 to anhydrous ethanol at a mass ratio of 1:1. Stir until homogeneous, and then ultrasonically disperse at 30°C for 0.5 h. Add 0.8 wt% polyvinylpyrrolidone (PVP), stir for 20 min, and then add ammonia to adjust the pH to 10 to obtain an alumina ethanol suspension.

[0041] S2. Treat other oxides in the additives using the same steps, and add 0.5% hydroxyethyl cellulose (HEC) if necessary to inhibit sedimentation; S3. Add tetraethyl orthosilicate (TEOS) and an appropriate amount of anhydrous ethanol and stir until fully dissolved. Add calcium ethanol, magnesium methoxide and triethyl borate in sequence according to the mass percentage of CaO:MgO:SiO2:B2O3 of 20:10:30:40, and stir for 1 hour to obtain glass sol. S4. Lanthanum oxide ethanol suspension, yttrium oxide ethanol suspension, zinc oxide ethanol suspension, zirconium dioxide ethanol suspension, samarium oxide ethanol suspension, and magnesium oxide ethanol suspension were sequentially added to alumina ethanol suspension. Then, 0.4 wt% glass sol of glass phase additive was added, stirred evenly, ultrasonically dispersed at 30°C for 2 hours, allowed to stand at room temperature for 24 hours, dried at 80°C and sieved (320 mesh sieve) to obtain alumina ceramic substrate material. S5. Add ceramic material, polyvinyl butyral, and dispersant to the organic solvent and perform sand milling. The ratio of material:ball:solution is 1:5:2. Perform sand milling cycles 25 times, each for 10 minutes, to obtain ceramic slurry.

[0042] S6. The ceramic slurry is used to prepare a 160μm ceramic film using a thick film casting machine; vacuum degassing is used to control the viscosity of the slurry at 13000cp.

[0043] S7. The ceramic films are stacked to form a green body and sintered. The sintering curves are shown in Table 2 to obtain alumina ceramic substrate material.

[0044] Example 4 This embodiment provides a method for preparing an alumina ceramic substrate material. Unlike Embodiment 1, the formulation composition and dosage in this embodiment are different. The formulation composition is as follows: 99.342 wt% Al2O3, 0.06 wt% La2O3, 0.02 wt% Y2O3, 0.02 wt% ZnO, 0.18 wt% ZrO2, 0.05 wt% Sm2O3, 0.028 wt% MgO, and 0.3 wt% glass cooling agent.

[0045] The specific preparation method is as follows: S1. Slowly add Al2O3 to anhydrous ethanol at a mass ratio of 1:1. Stir until homogeneous, and then ultrasonically disperse at 30°C for 0.5 h. Add 0.8 wt% polyvinylpyrrolidone (PVP), stir for 20 min, and then add ammonia to adjust the pH to 10 to obtain an alumina ethanol suspension.

[0046] S2. Treat other oxides in the additives using the same steps, and add 0.5% hydroxyethyl cellulose (HEC) if necessary to inhibit sedimentation; S3. Add tetraethyl orthosilicate (TEOS) and an appropriate amount of anhydrous ethanol and stir until fully dissolved. Add calcium ethanol, magnesium methoxide and triethyl borate in sequence according to the mass percentage of CaO:MgO:SiO2:B2O3 of 20:10:30:40, and stir for 1 hour to obtain glass sol. S4. Lanthanum oxide ethanol suspension, yttrium oxide ethanol suspension, zinc oxide ethanol suspension, zirconium dioxide ethanol suspension, samarium oxide ethanol suspension, and magnesium oxide ethanol suspension were sequentially added to alumina ethanol suspension. Then, 0.4 wt% glass sol of glass phase additive was added, stirred evenly, ultrasonically dispersed at 30°C for 2 hours, allowed to stand at room temperature for 24 hours, dried at 80°C and sieved (320 mesh sieve) to obtain alumina ceramic substrate material. S5. Add ceramic material, polyvinyl butyral, and dispersant to the organic solvent and perform sand milling. The ratio of material:ball:solution is 1:5:1.5. Perform sand milling 10 times, 15 minutes each time, to obtain ceramic slurry.

[0047] S6. Prepare a 165μm ceramic film from the ceramic slurry using a thick film casting machine; control the viscosity of the slurry to 15000cp by vacuum degassing.

[0048] S7. The ceramic films are stacked to form a green body and sintered. The sintering curves are shown in Table 2 to obtain alumina ceramic substrate material.

[0049] Example 5 This embodiment provides a method for preparing an alumina ceramic substrate material. Unlike Embodiment 1, the formulation composition and dosage in this embodiment are different. The formulation composition is: 99.4 wt% Al2O3, 0.03 wt% La2O3, 0.01 wt% Y2O3, 0.01 wt% ZnO, 0.09 wt% ZrO2, 0.05 wt% Sm2O3, 0.01 wt% MgO, and 0.4 wt% glass cooling agent.

[0050] The specific preparation method is as follows: S1. Slowly add Al2O3 to anhydrous ethanol at a mass ratio of 1:1. Stir until homogeneous, and then ultrasonically disperse at 30°C for 0.5 h. Add 0.8 wt% polyvinylpyrrolidone (PVP), stir for 20 min, and then add ammonia to adjust the pH to 10 to obtain an alumina ethanol suspension.

[0051] S2. Treat other oxides in the additives using the same steps, and add 0.5% hydroxyethyl cellulose (HEC) if necessary to inhibit sedimentation; S3. Add tetraethyl orthosilicate (TEOS) and an appropriate amount of anhydrous ethanol and stir until fully dissolved. Add calcium ethanol, magnesium methoxide and triethyl borate in sequence according to the mass percentage of CaO:MgO:SiO2:B2O3 of 20:10:30:40, and stir for 1 hour to obtain glass sol. S4. Lanthanum oxide ethanol suspension, yttrium oxide ethanol suspension, zinc oxide ethanol suspension, zirconium dioxide ethanol suspension, samarium oxide ethanol suspension, and magnesium oxide ethanol suspension were sequentially added to alumina ethanol suspension. Then, 0.4 wt% glass sol of glass phase additive was added, stirred evenly, ultrasonically dispersed at 30°C for 2 hours, allowed to stand at room temperature for 24 hours, dried at 80°C and sieved (320 mesh sieve) to obtain alumina ceramic substrate material. S5. Add ceramic material, polyvinyl butyral, and dispersant to the organic solvent and perform sand milling. The ratio of material:ball:solution is 1:5:2.5. Perform sand milling cycles 15 times, each for 20 minutes, to obtain ceramic slurry.

[0052] S6. The ceramic slurry is used to prepare a 160μm ceramic film using a thick film casting machine; vacuum degassing is used to control the viscosity of the slurry at 13000cp.

[0053] S7. The ceramic films are stacked to form a green body and sintered. The sintering curves are shown in Table 2 to obtain alumina ceramic substrate material.

[0054] Comparative Example 1 This comparative example provides a method for preparing an alumina ceramic substrate material. Unlike Example 1, the Al2O3 content in this comparative example is less than the minimum value, and the ZrO2 content is higher than the maximum value. Its formulation is as follows: 99.1 wt% Al2O3, 0.15 wt% La2O3, 0.05 wt% Y2O3, 0.03 wt% ZnO, 0.2 wt% ZrO2, 0.05 wt% Sm2O3, 0.02 wt% MgO, and 0.4 wt% glass cooling agent.

[0055] Comparative Example 2 This comparative example provides a method for preparing an alumina ceramic substrate material. Unlike Example 2, the Al2O3 content in this comparative example is higher than the maximum value, no ZnO is added, and there are fewer particle size refiners. Its formulation is as follows: 99.8 wt% Al2O3, 0.03 wt% La2O3, 0.01 wt% Y2O3, 0.05 wt% ZrO2, 0.01 wt% Sm2O3, and 0.1 wt% glass cooling agent.

[0056] Comparative Example 3 This comparative example provides a method for preparing an alumina ceramic substrate material. Unlike Example 5, this comparative example does not add particle size refiners. Its formulation consists of 99.37 wt% Al2O3, 0.03 wt% ZnO, 0.2 wt% ZrO2, and 0.4 wt% glass cooling agent.

[0057] Comparative Example 4 This comparative example provides a method for preparing an alumina ceramic substrate material. Unlike Example 3, this comparative example does not include ZrO2. Its formulation consists of: 99.252 wt% Al2O3, 0.18 wt% La2O3, 0.06 wt% Y2O3, 0.03 wt% ZnO, 0.05 wt% Sm2O3, 0.028 wt% MgO, and 0.4 wt% glass cooling agent.

[0058] Comparative Example 5 This comparative example provides a method for preparing an alumina ceramic substrate material. Unlike Example 4, this comparative example does not include a glassy phase cooling agent. Its formulation consists of: 99.4 wt% Al2O3, 0.15 wt% La2O3, 0.05 wt% Y2O3, 0.18 wt% ZnO, 0.15 wt% ZrO2, 0.05 wt% Sm2O3, and 0.02 wt% MgO.

[0059] In Examples 1-5 and Comparative Examples 1-5, during the sintering of the samples, such as Figure 1 As shown, place the ceramic substrate product on the lower firing plate and then place the L-shaped corner blocks. The length and width dimensions of the L-shaped corner blocks must satisfy the following: d / 2≤2 l ≤3 / 4 d ;thickness t 2. With product thickness t The following conditions must be met between 1 and 2: t 1≤ t 2≤5 t1. During sintering, the lower firing plates containing the product are stacked one by one for sintering, according to the product thickness and the temperature field distribution inside the sintering furnace, before the top firing plate is placed, ensuring a consistent sintering environment for each layer of product. The two firing plates and L-shaped corner blocks create a relatively stable, narrow space, ensuring the large-size ceramic substrate remains flat and does not warp, and that the density of each area of ​​the substrate is consistent, thus guaranteeing stable performance. The L-shaped corner blocks do not completely enclose this space, allowing for normal airflow and ensuring uniform and dense sintering of the product. The symmetrical placement of the L-shaped corner blocks ensures normal airflow, reducing the amount of airborne particles remaining in the substrate sintering area and causing defects. A schematic diagram of the sintering curve is shown below. Figure 2 As shown, in addition to the debinding stage, a grain growth stage and a grain densification stage are set up, and a relatively fast heating rate is adopted. v 1. Reaching temperature T 1. Insulation t 1. Allow time for the grains to grow uniformly, then use... v 2. Slowly increase the temperature to the final temperature. T 2. This allows the grains to grow slowly and provides insulation. t 2. Ensure uniform grain length and densification. This allows for the production of large-size alumina ceramic substrates that are flat, non-warped, and free of surface defects.

[0060] The dielectric properties of the alumina ceramic substrate samples prepared in Example 3 were tested at different frequencies. Since different frequencies require different sample sizes, several films from the same batch were randomly selected and prepared into samples for different frequencies for testing. Performance fluctuations at the same frequency can reflect performance differences in different areas of a large-size product; while different frequencies can reflect the fluctuations in the performance of the alumina ceramic substrate material. Table 1 shows the sample sizes and thicknesses used for different frequencies.

[0061] Table 1

[0062] Test results as follows Figure 3 As shown, from Figure 3 As can be seen from the above, the dielectric constant and dielectric loss of the alumina ceramic substrate prepared in Example 3 at different frequencies all satisfy the following: Standard deviation S Within ±5%, the coefficient of variation (CV) is less than 15% (empirical threshold). The alumina ceramic substrate prepared in Example 3 has small performance fluctuations and can be used to prepare large-size ceramic substrates. The performance changes of samples of different sizes at different frequencies are relatively stable.

[0063] Table 2 shows the sintering curves for the examples and comparative examples.

[0064] Table 2. Sintering curves of each embodiment and comparative example.

[0065] Table 3 shows the performance of the samples prepared in the examples and comparative examples.

[0066] Table 3 Performance of each embodiment and comparative example

[0067] The flexural strength of the alumina ceramic substrates prepared in Examples 1, 3, 1, and 4 was tested, and the results are as follows: Figure 4 And as shown in Table 3. From Figure 4 As shown in Table 3, the average flexural strengths of the alumina ceramic substrates prepared in Examples 1, 3, Comparative Example 1, and Comparative Example 3 are 765.41 MPa, 791.04 MPa, 689.74 MPa, and 711.89 MPa, respectively. Examples 1 and 3 meet the requirements for large-size ceramic substrates. Comparative Example 1 has low flexural strength due to excessively low Al2O3 content, excessively high ZrO2 content, and a slightly elevated sintering densification temperature, indicating insufficient sintering and no noticeable toughening effect. As shown in Table 3, the dielectric constant is low, the dielectric loss is high, and the flexural strength is slightly low. Compared to Example 3, Comparative Example 4 did not add ZrO2. As shown in Table 3, other properties are acceptable, but the flexural strength is slightly lower.

[0068] Compared with Example 1, Comparative Example 1 had a lower Al2O3 content than the minimum value, a slightly higher ZrO2 content, insufficient sintering density, a slightly lower dielectric constant, slightly higher dielectric loss, and the toughening effect of ZrO2 was not fully realized, resulting in slightly lower flexural strength. Compared with Example 2, Comparative Example 2 had a higher Al2O3 content than the maximum value, no ZnO was added, the liquid phase wetting effect was not obvious, the sintering driving force was insufficient, it was not fully sintered, the density was low, the dielectric constant was low, the modifier was insufficient, abnormal grain growth occurred, the dielectric loss was high, and the resistance was low. The bending strength is low. Compared with Example 5, Comparative Example 3 did not add La2O3, Y2O3, Sm2O3, and MgO. The grains grew abnormally, and the toughening effect of ZrO2 phase transformation and microcrack toughening was not obvious and unstable. The dielectric constant and dielectric loss were relatively high. Compared with Example 3, Comparative Example 4 did not have a toughening effect and the bending strength was slightly lower. Compared with Example 4, Comparative Example 5 did not add a glass phase cooling agent. The driving force for liquid phase sintering was insufficient, making it difficult to fire into ceramic. The dielectric constant, dielectric loss, and bending strength were relatively low.

[0069] like Figure 5 The image shown is a roughness test result diagram of different points of the alumina ceramic substrate material prepared in Example 3; Figure 6 Here is a physical image of the alumina ceramic substrate material prepared in Example 3, from... Figure 5 and Figure 6 As can be seen from the test, the sample prepared in Example 3 is as follows: Figure 6The roughness Ra of 100 points on the large-size sample is distributed within 50±10nm, indicating that the roughness is consistent.

[0070] Finally, it should be noted that the specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention. It is obvious to those skilled in the art that this application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or basic characteristics of the present application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this application is defined by the appended claims rather than the foregoing description, and therefore all changes falling within the meaning and scope of the equivalents of the claims are intended to be included within this application.

Claims

1. An alumina ceramic substrate material, characterized in that, Depend on It consists of modifiers and glass phase cooling agents, comprising 99.2~99.6 wt% by mass. 0.2~0.4wt% modifier, 0.1~0.4wt% glass phase cooling agent.

2. The alumina ceramic substrate material according to claim 1, characterized in that, The modifier, by mass percentage, comprises 0.03wt%~0.15wt% of La2O3, 0.01wt%~0.05wt% of Y2O3, 0.01wt%~0.03wt% of ZnO, 0.05wt%~0.18wt% of ZrO2, 0.01wt%~0.05wt% of Sm2O3, and 0.01wt%~0.028wt% of MgO.

3. The alumina ceramic substrate material according to claim 1, characterized in that, The glass cooling agent is Ca-Mg-B-Si glass.

4. The alumina ceramic substrate material according to claim 1, characterized in that, The glass cooling agent comprises, by mass percentage, 20wt%~30wt% Ca(OCH2CH3)2, 5wt%~15wt% Mg(OCH3)2, 30wt%~45wt% Si(OCH2CH3)4, and 10wt%~45wt% B(OCH2CH3)3.

5. A method for preparing an alumina ceramic substrate material, characterized in that, Includes the following steps: Will Add anhydrous ethanol, stir well, then add polyvinylpyrrolidone, and add ammonia to adjust the pH to strong alkalinity to obtain an aluminum oxide ethanol suspension. Adopted and The same method was used to treat La2O3, Y2O3, ZnO, ZrO2, Sm2O3, and MgO to obtain lanthanum oxide ethanol suspension, yttrium oxide ethanol suspension, zinc oxide ethanol suspension, zirconium dioxide ethanol suspension, samarium oxide ethanol suspension, and magnesium oxide ethanol suspension. Tetraethyl orthosilicate was dissolved in anhydrous ethanol, and then calcium ethoxide, magnesium methoxide, and triethyl borate solution were added in sequence and stirred to obtain a glass sol. Lanthanum oxide ethanol suspension, yttrium oxide ethanol suspension, zinc oxide ethanol suspension, zirconium dioxide ethanol suspension, samarium oxide ethanol suspension, and magnesium oxide ethanol suspension were added to alumina ethanol suspension, followed by glass sol. The mixture was stirred until homogeneous, ultrasonically dispersed, allowed to stand at room temperature for aging, dried, and sieved to obtain the ceramic material. Porcelain slurry is obtained by adding ceramic materials, binders, dispersants, and additives to an organic solvent and then milling it. The ceramic slurry is used to form ceramic films using a thick film casting machine; The ceramic films are stacked to form a green body, which is then sintered to obtain an alumina ceramic substrate material.

6. The method for preparing an alumina ceramic substrate material according to claim 5, characterized in that, When preparing the porcelain slurry, the ratio of material:ball:solution = 1:5:(1.5~3) should be followed.

7. The method for preparing an alumina ceramic substrate material according to claim 6, characterized in that, The sanding cycle is repeated 10-30 times, each cycle lasting 8-20 minutes.

8. The method for preparing an alumina ceramic substrate material according to claim 5, characterized in that, The organic solvent is a mixture of anhydrous ethanol and toluene, wherein the mass ratio of anhydrous ethanol to toluene is 1:(1~5).

9. The method for preparing an alumina ceramic substrate material according to claim 5, characterized in that, The adhesive comprises polyvinyl butyral.

10. A ceramic substrate, characterized in that, Includes the alumina ceramic substrate material according to any one of claims 1 to 4 or the alumina ceramic substrate material prepared by the preparation method according to any one of claims 5 to 9.

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