High-performance aluminum oxide ceramic substrate and preparation method thereof

Abstract

The invention discloses a high-performance aluminum oxide ceramic substrate and a preparation method thereof, and the high-performance aluminum oxide ceramic substrate comprises the following components in parts by weight: 80-90 parts of ceramic balls, 8-15 parts of aluminum oxide, 0.1-05 parts of calcined talc, 0.1-0.3 part of white fire clay, 0.1-0.3 part of lanthanum oxide, 0.1-0.2 part of strontium carbonate and 7-8 parts of water. By optimizing the proportion of components such as the ceramic balls and aluminum oxide and the sintering process, the sintering temperature is lower than that of a traditional sintering mode, energy is saved, the product performance index is good, and the stability is high.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of alumina ceramic substrate processing, in particular to a high-performance alumina ceramic substrate and a preparation method thereof. BACKGROUND

[0002] As an important ceramic material, the alumina ceramic substrate is widely applied to the fields of electronics, communication, aviation and machinery due to high hardness, high wear resistance, high insulation, high thermal stability and good chemical stability. Traditional alumina ceramic substrate production processes mainly include raw material preparation, molding, sintering and post-processing steps. However, the existing technology has problems such as high energy consumption, grain coarsening and unstable product performance in the preparation process.

[0003] Although the high-temperature sintering method commonly used in the prior art has mature technology and low equipment threshold, the energy consumption is high, and the grains are prone to coarsening in the sintering process, which affects the mechanical properties and thermal properties of the product. In addition, although the colloidal method / precursor method is controllable in microstructure, the sol stability is poor and the mass production cost is high. Although the flow casting method is suitable for thin products, the slurry dispersibility is strict, and cracks and uneven thickness are prone to occur.

[0004] Therefore, the application provides a high-performance alumina ceramic substrate and a preparation method thereof. SUMMARY

[0005] The application aims to provide a high-performance alumina ceramic substrate and a preparation method thereof, which solves the problems in the background art.

[0006] To achieve the above-mentioned purpose, the application provides the following technical scheme: a high-performance alumina ceramic substrate, which comprises the following weight components:

[0007] Porcelain ball 80-90 parts, alumina 8-15 parts, calcined talc 0.1-0.5 parts, white fire mud 0.1-0.3 parts, lanthanum oxide 0.1-0.3 parts, strontium carbonate 0.1-0.2 parts and water 7-8 parts.

[0008] As a preferred embodiment of the application, the following weight components are included:

[0009] Porcelain ball 88 parts, alumina 11 parts, calcined talc 0.27 parts, white fire mud 0.26 parts, lanthanum oxide 0.13 parts, strontium carbonate 0.11 parts and water 7.5 parts.

[0010] As a preferred embodiment of the application, the following weight components are included:

[0011] Porcelain ball 85 parts, alumina 12 parts, calcined talc 0.27 parts, white fire mud 0.26 parts, lanthanum oxide 0.13 parts, strontium carbonate 0.11 parts and water 7.5 parts.

[0012] As a preferred embodiment of the present application, it comprises the following weight components:

[0013] Porcelain ball 80 parts, alumina 15 parts, calcined talc 0.27 parts, white fire clay 0.26 parts, lanthanum oxide 0.13 parts, strontium carbonate 0.11 parts, water 7.5 parts.

[0014] The present application also relates to a high-performance alumina ceramic substrate preparation method, comprising the following method steps:

[0015] Step one: accurately weigh the raw materials such as alumina, calcined talc, white fire clay, lanthanum oxide, strontium carbonate, and an appropriate amount of water according to the formula ratio;

[0016] Step two: add the weighed raw materials into the ball mill, add an appropriate amount of water as medium, start the ball mill to ball mill the materials, ensure that the raw materials are fully mixed and uniform, form a fine slurry, dry the ball-milled slurry to remove excess water, and obtain dry powder;

[0017] Step three: preliminarily pre-press the dry powder to have a certain shape and strength for subsequent molding, and put the pre-pressed powder into a die pressing machine to prepare a green body of the required shape by rolling;

[0018] Step four: put the green body into a sintering furnace for sintering, and after sintering, cool the furnace to below 100℃ to avoid cracks in the ceramic substrate due to rapid cooling.

[0019] As a preferred embodiment of the present application, the sintering comprises glue removal treatment, low-temperature sintering, and high-temperature sintering;

[0020] Glue removal treatment: put the green body into a sintering furnace, heat to 500℃ at a heating rate of 5℃ / min, and keep for 1h to remove organic additives and moisture in the green body;

[0021] Low-temperature sintering: continue to heat to 920℃ at a heating rate of 5℃ / min, and keep for 1h to make the particles in the green body begin to combine preliminarily;

[0022] High-temperature sintering: reduce the heating rate to 3℃ / min, heat to 1469℃, and keep for 2h to make the alumina powder particles react in solid phase to form a dense ceramic structure.

[0023] As a preferred embodiment of the present application, the pressure condition of the rolling in step three is a pressure of 170MPa.

[0024] As a preferred embodiment of the present application, the rotating speed of the ball mill in step two is 400rpm, and the ball milling time is 46h.

[0025] Compared with the prior art, the application has the following advantages:

[0026] The application optimizes the ratio of the porcelain ball and alumina and other components and the sintering process, so that the sintering temperature is lower than that of the traditional sintering method, energy is saved, the product performance index is good, and the stability is high.

[0027] The sintered ceramic substrate has excellent mechanical properties, thermal properties and electrical properties:

[0028] Mechanical properties: surface roughness Ra≤0.8um, bulk density≥3.7g / cm 3 , bending strength≥274g / cm 3 ;

[0029] Thermal properties: linear expansion coefficient 6.2-6.8×10 -6 mm / ℃, thermal conductivity≥21W / m·K, specific heat≥0.8kJ / (kg·K);

[0030] Electrical properties: volume resistivity≥10 14 Ω·cm, breakdown strength≥15kv / mm, dielectric constant 9-10(1MHz), loss tangent≤3×10 -4 (1MHz);

[0031] The alumina ceramic substrate prepared by the application has low surface roughness, effectively reduces surface defects, and is beneficial to improve the adhesion and electrical connection stability of the substrate and other materials; the moderate bulk density is beneficial to avoid processing difficulties caused by excessive densification while ensuring structural densification, and has high bending strength and can withstand large mechanical stress without being easily damaged; good thermal conductivity helps rapid heat dissipation to ensure stable operation of electronic components in high temperature environment; excellent volume resistivity and breakdown strength provide reliable electrical insulation performance, which is beneficial to prevent electric leakage and breakdown; moderate dielectric constant and low loss tangent make it have excellent signal transmission performance in high frequency circuits, which is beneficial to reduce energy loss. BRIEF DESCRIPTION OF DRAWINGS

[0032] Other features, objects and advantages of the application will become more apparent after reading the detailed description of the non-limiting embodiments with reference to the following drawings:

[0033] Figure 1 A high-performance alumina ceramic substrate preparation method flowchart of the application. DETAILED DESCRIPTION

[0034] In order to make the technical means, creative features, purposes and effects of the application easy to understand, the application is further described below in combination with specific embodiments.

[0035] The present application provides a kind of high-performance alumina ceramic substrate, including the following weight components:

[0036] Porcelain ball 80-90 parts, alumina 8-15 parts, calcined talc 0.1-05 parts, white fire clay 0.1-0.3 parts, lanthanum oxide 0.1-0.3 parts, strontium carbonate 0.1-0.2 parts, water 7-8 parts.

[0037] Example 1

[0038] First prepare raw materials: porcelain ball 88 parts, alumina 11 parts, calcined talc 0.27 parts, white fire clay 0.26 parts, lanthanum oxide 0.13 parts, strontium carbonate 0.11 parts, water 8 parts;

[0039] According to the formula proportion, accurately weigh alumina, calcined talc, white fire clay, lanthanum oxide, strontium carbonate and other raw materials, and an appropriate amount of water, then add the weighed raw materials into the ball mill, add an appropriate amount of water as medium, start the ball mill to ball mill the materials, the rotation speed of the ball mill is 400 rpm, the ball milling time is 46 h, to ensure that the raw materials are fully mixed and uniform, form a fine slurry, dry the ball-milled slurry to remove excess water, obtain dry powder, dry the powder after drying, and preliminarily pre-press to have a certain shape and strength, which is convenient for subsequent molding, put the pre-pressed powder into a film sealing machine, and prepare a green body of the required shape by rolling under the pressure condition of 170 MPa, put the green body into a sintering furnace for sintering, which includes glue removal treatment, low temperature sintering and high temperature sintering; glue removal treatment: put the green body into the sintering furnace, heat to 500℃ at a heating rate of 5℃ / min, and keep for 1h to remove organic additives and moisture in the green body; low temperature sintering: continue to heat to 920℃ at a heating rate of 5℃ / min, and keep for 1h to make the particles in the green body begin to combine preliminarily; high temperature sintering: reduce the heating rate to 3℃ / min, heat to 1469℃, and keep for 2h to make the alumina powder particles react in solid phase and form a dense ceramic structure, after sintering, cool to below 100℃ in the furnace to avoid cracks in the ceramic substrate due to rapid cooling.

[0040] Example 2

[0041] First prepare raw materials: porcelain ball 85 parts, alumina 12 parts, calcined talc 0.27 parts, white fire clay 0.26 parts, lanthanum oxide 0.13 parts, strontium carbonate 0.11 parts, water 7.5 parts;

[0042] According to the proportion of the formula, the alumina, calcined talc, white fire clay, lanthanum oxide, strontium carbonate and other raw materials are accurately weighed, and an appropriate amount of water is added. Then the weighed raw materials are added into the ball mill, and an appropriate amount of water is added as medium. The ball mill is started to ball mill the materials. The rotation speed of the ball mill is 400 rpm, and the ball milling time is 46 h. The raw materials are fully mixed and uniformly distributed to form a fine slurry. The slurry after ball milling is dried to remove excess water, and a dry powder is obtained. The dry powder is preliminarily pre-pressed to have a certain shape and strength, which is convenient for subsequent molding. The pre-pressed powder is put into a film sealing machine, and a green body with the required shape is prepared by rolling at a pressure of 170 MPa. The green body is put into a sintering furnace for sintering, which includes glue removal treatment, low temperature sintering and high temperature sintering. The glue removal treatment: the green body is put into the sintering furnace, heated to 500℃ at a heating rate of 5℃ / min, and kept for 1h to remove organic additives and water in the green body. The low temperature sintering: continue to heat to 920℃ at a heating rate of 5℃ / min, and keep for 1h to make the particles in the green body begin to combine. The high temperature sintering: reduce the heating rate to 3℃ / min, heat to 1469℃, and keep for 2h to make the alumina powder particles react in solid phase and form a dense ceramic structure. After sintering, the furnace is cooled to below 100℃ to avoid cracks in the ceramic substrate due to rapid cooling.

[0043] Example 3

[0044] First, prepare the raw materials: 80 parts of porcelain balls, 15 parts of alumina, 0.27 parts of calcined talc, 0.26 parts of white fire clay, 0.13 parts of lanthanum oxide, 0.11 parts of strontium carbonate, and 7.5 parts of water;

[0045] According to the proportion of the formula, the alumina, the burnt talc, the white fire mud, the lanthanum oxide, the strontium carbonate and the like are accurately weighed, and then the weighed raw materials are added into a ball mill, an appropriate amount of water is added as a medium, the ball mill is started, and the material is ball milled, the rotating speed of the ball mill is 400 rpm, the ball milling time is 46 h, the raw materials are ensured to be fully mixed and uniform, a fine slurry is formed, the slurry after ball milling is dried to remove the excess water, and the dry powder is obtained, the dry powder is preliminarily pre-pressed to have a certain shape and strength, so that the subsequent forming is facilitated, the pre-pressed powder is placed into a film sealing machine, and a green body with a required shape is prepared by rolling at a pressure of 170 MPa, and the green body is placed into a sintering furnace for sintering, and the sintering includes glue removal treatment, low-temperature sintering and high-temperature sintering; the glue removal treatment: the green body is placed into the sintering furnace, heated to 500 DEG C at a heating rate of 5 DEG C / min, and kept for 1 h, so as to remove the organic additives and water in the green body; the low-temperature sintering: the heating rate is continuously 5 DEG C / min, heated to 920 DEG C, and kept for 1 h, so that the particles in the green body begin to combine preliminarily; the high-temperature sintering: the heating rate is reduced to 3 DEG C / min, heated to 1469 DEG C, and kept for 2 h, so that the solid-phase reaction occurs between the alumina powder particles, and a dense ceramic structure is formed, and after the sintering is completed, the furnace is cooled to below 100 DEG C, so as to avoid cracks of the ceramic substrate due to rapid cooling.

[0046] The products obtained in Examples 1-3 are tested, and the performance is shown in the following table:

[0047] Mechanical properties:

[0048]

[0049] Thermal properties:

[0050]

[0051] Electrical properties:

[0052]

[0053]

[0054] In summary, by adopting the formula and the sintering process, the sintering temperature is lower than that of the traditional sintering mode, energy is saved, the product performance index is good, and the stability is high.

[0055] The sintered ceramic substrate has excellent mechanical properties, thermal properties and electrical properties:

[0056] Mechanical properties: surface roughness Ra≤0.8 um, bulk density≥3.7 g / cm 3 , bending strength≥274 g / cm 3 ;

[0057] Thermal properties: linear expansion coefficient 6.2-6.8 x 10 -6 mm / °C, thermal conductivity ≥ 21 W / m-K, specific heat ≥ 0.8 kJ / (kg-K);

[0058] Electrical properties: volume resistivity ≥ 10 14 Ω-cm, breakdown strength ≥ 15 kV / mm, dielectric constant 9-10 (1 MHz), loss tangent ≤ 3 x 10 -4 (1 MHz).

[0059] The above shows and describes the basic principles and main features of the present application and the advantages of the present application, and it is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting in any respect, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed by the present application.

[0060] Furthermore, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the present specification is described in this way only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A high-performance alumina ceramic substrate, characterized by: It contains the following components by weight: 80-90 parts of porcelain balls, 8-15 parts of aluminum oxide, 0.1-05 parts of burned talc, 0.1-0.3 parts of white fire clay, 0.1-0.3 parts of lanthanum oxide, 0.1-0.2 parts of strontium carbonate, and 7-8 parts of water.

2. The high-performance alumina ceramic substrate according to claim 1, characterized in that: It contains the following components by weight: 88 parts of porcelain balls, 11 parts of aluminum oxide, 0.27 parts of burned talc, 0.26 parts of white fire clay, 0.13 parts of lanthanum oxide, 0.11 parts of strontium carbonate, and 8 parts of water.

3. The high-performance alumina ceramic substrate according to claim 1, characterized in that: It contains the following components by weight: 85 parts of porcelain balls, 12 parts of aluminum oxide, 0.27 parts of burned talc, 0.26 parts of white fire clay, 0.13 parts of lanthanum oxide, 0.11 parts of strontium carbonate, and 7.5 parts of water.

4. The high-performance alumina ceramic substrate according to claim 1, characterized in that: It contains the following components by weight: 80 parts of porcelain balls, 15 parts of aluminum oxide, 0.27 parts of burned talc, 0.26 parts of white fire clay, 0.13 parts of lanthanum oxide, 0.11 parts of strontium carbonate, and 7.5 parts of water.

5. A method for preparing a high-performance alumina ceramic substrate, suitable for the high-performance alumina ceramic substrate according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: Step 1: Accurately weigh raw materials such as alumina, calcined talc, white fire clay, lanthanum oxide, strontium carbonate, and an appropriate amount of water according to the formula ratio; Step 2: Add the weighed raw materials into the ball mill, add an appropriate amount of water as a medium, start the ball mill to mill the materials, ensure that the raw materials are fully mixed and evenly, form a fine slurry, dry the milled slurry to remove excess water, and obtain a dry powder; Step 3: Pre-press the dried powder to give it a certain shape and strength to facilitate subsequent molding. The pre-pressed powder is placed in a die-casting machine and rolled to produce a green body of the desired shape. Step 4: Place the green body into a sintering furnace for sintering. After sintering, cool it to below 100°C in the furnace to avoid cracks in the ceramic substrate due to rapid cooling.

6. The method for preparing a high-performance alumina ceramic substrate according to claim 5, wherein: The sintering includes debinding treatment, low temperature sintering and high temperature sintering; Debinding treatment: Place the green body in a sintering furnace, heat it to 500°C at a heating rate of 5°C / min, and keep it at this temperature for 1 hour to remove organic additives and moisture in the green body; Low-temperature sintering: Continue heating to 920°C at a heating rate of 5°C / min and keep at this temperature for 1 hour to allow the particles in the green body to begin to initially combine; High-temperature sintering: Reduce the heating rate to 3°C / min, heat to 1469°C, and keep warm for 2 hours to allow a solid-phase reaction to occur between the alumina powder particles to form a dense ceramic structure.

7. The method for preparing a high-performance alumina ceramic substrate according to claim 5, wherein: The pressure condition for rolling in step 3 is a pressure of 170 MPa.

8. The method for preparing a high-performance alumina ceramic substrate according to claim 5, wherein: The rotation speed of the ball mill in step 2 is 400 rpm, and the ball milling time is 46 h.

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