Dielectric material for wafer type ceramic capacitor and preparation method and application of dielectric material

Abstract

The invention relates to a wafer type ceramic capacitor dielectric material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing barium titanate, a rare earth oxide auxiliary agent and a silica sol solution, granulating, pressing to obtain a green body, and sintering the green body to obtain the wafer type ceramic capacitor dielectric material. The silica sol solution is added into a formula system, the silica sol solution is used for replacing a traditional powdery silicon dioxide additive and an organic binder added in the granulation process, the glue discharging time in the sintering process is greatly shortened, the silica sol solution can serve as a silicon source of the silicon dioxide additive, the sintering temperature of a green body is reduced, and meanwhile the sintering temperature of the green body is lowered. According to the preparation method, the density of the wafer type ceramic capacitor dielectric material can be further improved, generation of air holes is reduced, the dielectric loss is reduced, the resistivity and the dielectric constant are improved, the production efficiency can be greatly improved, the cost can be greatly reduced, and meanwhile the product performance of the wafer type ceramic capacitor dielectric material can be further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic capacitor preparation, and in particular to a disc-type ceramic capacitor dielectric material and a preparation method and application thereof. Background Art

[0002] Disc ceramic capacitors are small, compact, high-precision electronic components with good frequency response. They have high dielectric constant, low loss, good temperature stability and withstand voltage, as well as fast response time. These characteristics make disc ceramic capacitors widely used in various electronic devices and become an indispensable component in many circuit designs. Optimizing the uniformity of electric field distribution is the key to improving the performance of disc capacitors. It is necessary to have a high dielectric constant to achieve a large capacitance value, and to ensure insulation performance and stability under high voltage to prevent breakdown. At the same time, the temperature coefficient of the material must meet the stability requirements of capacitor performance at different operating temperatures, which increases the complexity of material research and development. In the molding process of a single-layer disc, the thickness uniformity and surface flatness must be ensured, otherwise it will lead to uneven electric field distribution, excessive local electric field strength, and reduce the withstand voltage performance of the capacitor. At the same time, there should be no defects such as large pores or layer cracks in the blank, otherwise it will affect the dielectric strength of the porcelain body.

[0003] CN101550010A discloses a sintering method for a barium titanate-based ceramic capacitor dielectric, the steps of which are: (1) sintering a raw material according to the mass percentage content of Bi 2 O 3 25%-35%, Pb 3 O 4 15%-25%, ZnO 30%-40%, H 3 BO 3 10%-20% ingredients, mixing, melting quenching, grinding, sieving, preparing glass powder; (2) pre-treating the initial raw material barium titanate, adding Nb 2 O 5 0.5%-2%, glass powder 4%-10% ingredients, to prepare a green body; (3) preheating the sintering furnace to 1000 ℃ -1250 ℃, directly sintering, quenching at 400 ℃ -950 ℃, to obtain a barium titanate-based ceramic capacitor dielectric with a dielectric constant of about 1700 and a loss of less than 1.5% in the working temperature range (-55 ℃ -150 ℃). Since paraffin is used as a binder, the granulation process is relatively long and the production efficiency is relatively low.

[0004] CN118754645A discloses a modified barium titanate ceramic dielectric material, its preparation method and a ceramic capacitor. The preparation method includes the following steps: (1) Mix barium titanate material and an anti-reducing agent, then granulate and press into a sheet to obtain a green ceramic body; (2) Debind the green ceramic body, and then sinter the green ceramic body in a reducing atmosphere to obtain the modified barium titanate ceramic dielectric material; wherein, the anti-reducing agent includes V 2 O 5 and / or Cr 2 O 3 。The specific steps of the granulation include: adding a binder to the mixed mixture for granulation, and the binder includes polyvinyl alcohol (PVA). The dielectric constant of this ceramic dielectric material is 1250 - 1850, and the dielectric loss ≤ 5.5%. Although PVA is used as the binder, the density of the ceramic has been improved, but there is still room for improvement in the capacitance performance.

[0005] It can be seen that in the prior art, PVB, PVA or paraffin wax, etc. are usually added as granulation binders, and after the corresponding binder is added, low-temperature debinding is required, which will increase the total sintering time and reduce the production efficiency. At the same time, if the debinding process is not thorough, the carbon material decomposed from it will remain in the material, which will reduce the density of the material and thus reduce the product performance. In addition, to obtain a wafer capacitor material with a high dielectric constant and low dielectric loss, additives such as silica, lithium carbonate or boron oxide are usually added to reduce the sintering temperature of the barium titanate ceramic capacitor and avoid abnormal grain growth caused by high temperature.

[0006] Therefore, how to achieve the short-time and high-efficiency preparation of the dielectric material of the wafer ceramic capacitor, while taking into account that the dielectric material as a whole has better performance, that is, higher density, dielectric constant, resistivity and lower dielectric loss, etc., has become an urgent problem to be solved at present. Summary of the Invention

[0007] To solve the above technical problems, the present invention provides a dielectric material for a wafer ceramic capacitor, its preparation method and application. The present invention adds a silica sol solution to the formulation system, replacing the traditional powdery silica additive and the organic binder added during granulation, greatly reducing the debinding time during sintering, and the silica sol solution can be used as the silicon source of the silica additive. While reducing the sintering temperature of barium titanate, it can further improve the density of the dielectric material of the wafer ceramic capacitor, reduce the generation of pores, reduce the dielectric loss, increase the resistivity and dielectric constant. This preparation method can greatly improve the production efficiency and reduce the cost, and at the same time can further improve the product performance of the dielectric material of the wafer ceramic capacitor.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing a dielectric material for a wafer-type ceramic capacitor, and the preparation method includes the following steps:

[0010] After barium titanate, a rare earth oxide additive, and a silica sol solution are mixed and granulated, a green body is obtained through pressing, and the green body is sintered to obtain a dielectric material for a wafer-type ceramic capacitor.

[0011] In the present invention, the silica sol solution is used as both the silicon source of the silicon dioxide additive and the binder for granulation. Combined with the sintering process, the dielectric material for the wafer-type ceramic capacitor prepared has better density, reduced pores inside the material, reduced lattice defects, and the rare earth oxide additive and glass phase doping can fill the lattice gaps, thereby resulting in a lower dielectric loss.

[0012] The advantages of the dielectric material for the wafer-type ceramic capacitor prepared by the preparation process of the present invention are as follows: First, using silica sol as the silicon source to replace the silicon dioxide powder makes the mixing of silicon dioxide and powders such as barium titanate more uniform during the granulation process, enabling nanoscale silica colloidal particles to wrap on the surface of powders such as barium titanate. During the subsequent sintering process, a ceramic material with a high density can be sintered at a lower temperature, reducing the sintering temperature and avoiding the abnormal growth and excessive size of grains caused by too high sintering temperature, which leads to a decrease in product properties such as dielectric constant, loss, and breakdown resistance. Second, due to the omission of the addition of an organic binder, during the sintering process, the time for degumming is greatly reduced, and the overall time of the sintering section is further shortened, improving production efficiency and greatly reducing production costs at the same time. Third, the present invention also avoids the problem that when using an organic binder, due to insufficient degumming or other reasons, the organic binder cannot be completely removed, and some carbon-containing compounds remain in the dielectric material for the wafer-type ceramic capacitor, resulting in a decrease in the density of the material and a decrease in product performance.

[0013] As a preferred technical solution of the present invention, the silica sol solution includes an acidic silica sol solution or a neutral silica sol solution.

[0014] Preferably, the silica sol solution includes silicon dioxide and an aqueous solution.

[0015] Preferably, in the silica sol solution, the silicon dioxide accounts for ≥25 wt% of the total mass of the silica sol solution, such as 25 wt%, 28 wt%, 30 wt%, 32 wt%, 35 wt%, 38 wt%, 40 wt%, 45 wt% or 50 wt%, etc.

[0016] As a preferred technical solution of the present invention, the addition amount of the silica sol solution is based on the mass of the silicon dioxide, and the mass of the silicon dioxide in the added silica sol solution is 0.01 wt% - 2.0 wt% of the mass of the barium titanate; for example, 0.01 wt%, 0.1 wt%, 0.3 wt%, 0.5 wt%, 0.8 wt%, 1.0 wt%, 1.2 wt%, 1.5 wt%, 1.8 wt% or 2.0 wt%, etc.

[0017] In the present invention, in the added silica sol solution, the mass of the silicon dioxide is 0.01 wt% - 2.0 wt% of the mass of the barium titanate. First, it can better play the role of a granulation binder, avoiding uneven granulation and thus affecting the preparation of the later green body; second, it can better serve as a silicon source to control the addition amount of the silicon dioxide within a suitable range and play a role in further controlling the sintering temperature.

[0018] Preferably, the addition amount of the rare earth oxide additive is 0.1 wt% - 1.5 wt% of the mass of the barium titanate, for example, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt% or 1.5 wt%, etc.

[0019] It should be noted that the present invention does not make specific requirements and special limitations on the types of the rare earth oxide additives. As long as they are the types commonly used by those skilled in the art, they are applicable to the present invention. For example, they can be oxides of cerium, yttrium, praseodymium, niobium, gadolinium, holmium, dysprosium or iridium, etc.

[0020] As a preferred technical solution of the present invention, the heating rate of the sintering is 4.5 °C / min - 5.5 °C / min, for example, 4.5 °C / min, 4.8 °C / min, 5 °C / min, 5.2 °C / min or 5.5 °C / min, etc.

[0021] Preferably, the sintering temperature is 1200 °C - 1300 °C, for example, 1200 °C, 1210 °C, 1220 °C, 1230 °C, 1240 °C, 1250 °C, 1260 °C, 1270 °C, 1280 °C, 1290 °C or 1300 °C, etc.

[0022] As a preferred technical solution of the present invention, the heat preservation time of the sintering is 1.8 h - 2.2 h, for example, 1.8 h, 1.85 h, 1.9 h, 1.95 h, 2 h, 2.05 h, 2.1 h, 2.15 h or 2.2 h, etc.

[0023] Preferably, the total time of the heating-up process and the heat-preservation process of the sintering is 5.5 h - 6.7 h, such as 5.5 h, 5.6 h, 5.7 h, 5.8 h, 5.9 h, 6.0 h, 6.1 h, 6.2 h, 6.3 h, 6.4 h, 6.5 h, 6.6 h or 6.7 h, etc.

[0024] As a preferred technical solution of the present invention, the pressure of the pressing is 90 MPa - 800 Mpa, such as 90 MPa, 150 MPa, 200 MPa, 250 MPa, 300 MPa, 350 MPa, 400 MPa, 450 MPa, 500 MPa, 550 MPa, 600 MPa, 650 MPa, 700 MPa, 750 MPa or 800 MPa, etc., and preferably 200 MPa - 300 MPa.

[0025] As a preferred technical solution of the present invention, the preparation method includes the following steps:

[0026] Mix barium titanate, rare earth oxide additives and silica sol, granulate, then press under a pressure of 200 MPa - 300 Mpa to obtain a green body, heat up to 1200 °C - 1300 °C at a rate of 4.5 °C / min - 5.5 °C / min for sintering, keep the temperature for 1.8 h - 2.2 h, and the total time of the heating-up process and the heat-preservation process of the sintering is 5.5 h - 6.7 h to obtain a disc-shaped ceramic capacitor dielectric material;

[0027] The silica sol includes silicon dioxide and an aqueous solution; the silicon dioxide accounts for ≥ 25 wt% of the total mass of the silica sol; the addition amount of the silica sol is based on the mass of the silicon dioxide, and the mass of the silicon dioxide in the added silica sol is 0.01 wt% - 2.0 wt% of the mass of the barium titanate; the addition amount of the rare earth oxide additives is 0.1 wt% - 1.5 wt% of the mass of the barium titanate.

[0028] In the second aspect, the present invention also provides a disc-shaped ceramic capacitor dielectric material, and the disc-shaped ceramic capacitor dielectric material is prepared according to the preparation method described in the first aspect.

[0029] As a preferred technical solution of the present invention, the grain size of the disc-shaped ceramic capacitor dielectric material is 550 nm - 1150 nm, such as 550 nm, 650 nm, 750 nm, 850 nm, 950 nm, 1050 nm or 1150 nm, etc.

[0030] In the third aspect, the present invention also provides an application of a disc-shaped ceramic capacitor dielectric material, and the disc-shaped ceramic capacitor dielectric material described in the second aspect is applied to electronic components.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] 1) The present invention uses silica sol instead of traditional powdered silica additives and organic binders added during granulation, greatly reducing the debinding time during sintering, greatly improving production efficiency and reducing costs.

[0033] 2) The silica sol of the present invention can be used as the silicon source of the silica additive. While reducing the sintering temperature of the green body, it can further improve the density of the dielectric material of the wafer-type ceramic capacitor, reduce the generation of pores, reduce the dielectric loss, and improve the resistivity and dielectric constant.

[0034] 3) The dielectric material of the wafer-type ceramic capacitor prepared by the present invention has fewer internal pores, higher density, and better overall performance compared with the dielectric material of the wafer-type ceramic capacitor prepared by using traditional powdered silica additives and organic binder PVA. Description of the Drawings

[0035] Figure 1 is the surface SEM image of the dielectric material of the wafer-type ceramic capacitor prepared in Example 1 of the present invention.

[0036] Figure 2 is the surface SEM image of the dielectric material of the wafer-type ceramic capacitor prepared in Comparative Example 1 of the present invention. Detailed Embodiments

[0037] The technical solution of the present invention will be further described below with reference to the drawings and through specific embodiments. However, the following examples are only simple examples of the present invention and do not represent or limit the scope of the protection of the present invention. The scope of protection of the present invention is subject to the claims.

[0038] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.

[0039] The silica sol used in the detailed embodiments of the present invention is an aqueous colloidal solution with a commercially available silica content ≥ 25%, wherein the content of impurity sodium ions < 0.1%, and the silica colloidal particles are nanoscale with a particle size > 9 nm.

[0040] Example 1

[0041] This example provides a preparation method for a dielectric material of a wafer-type ceramic capacitor. The preparation method includes the following steps:

[0042] Weigh a certain mass of barium titanate and add Nb 2 O 5 and CeO 2A mixed powder and a silica sol solution, wherein the silica in the silica sol solution accounts for 28 wt% of the total mass. In the added silica sol solution, the mass of silica is 0.5 wt% of the mass of barium titanate. After mixing and granulating the above three components, they are pressed under a pressure of 250 Mpa to obtain a green body with a diameter of 10 mm and a thickness of 2 mm, and then sintered by heating to 1250 °C at a rate of 5 °C / min and holding for 2 h. The total time of the heating process and the holding process during sintering is 6.2 h, and a disc-shaped ceramic capacitor dielectric material is obtained.

[0043] Example 2

[0044] This example provides a preparation method of a disc-shaped ceramic capacitor dielectric material. The difference between this preparation method and that of Example 1 is that in the added silica sol solution, the mass of silica is 0.1 wt% of the mass of barium titanate, and the remaining preparation methods and parameters are the same as those of Example 1.

[0045] Example 3

[0046] This example provides a preparation method of a disc-shaped ceramic capacitor dielectric material. The difference between this preparation method and that of Example 1 is that in the added silica sol solution, the mass of silica is 1.5 wt% of the mass of barium titanate, and the remaining preparation methods and parameters are the same as those of Example 1.

[0047] Example 4

[0048] This example provides a preparation method of a disc-shaped ceramic capacitor dielectric material, and the preparation method includes the following steps:

[0049] Weigh a certain mass of barium titanate, and add Nb 2 O 5 and Y 2 O 3 mixed powder and a silica sol solution, wherein the silica in the silica sol solution accounts for 28 wt% of the total mass. In the added silica sol solution, the mass of silica is 0.01 wt% of the mass of barium titanate. After mixing and granulating the above three components, they are pressed under a pressure of 300 Mpa to obtain a green body with a diameter of 10 mm and a thickness of 2 mm, and then sintered by heating to 1200 °C at a rate of 5.5 °C / min and holding for 2.2 h. The total time of the heating process and the holding process during sintering is 5.9 h, and a ceramic capacitor dielectric material is obtained.

[0050] Example 5

[0051] This example provides a preparation method of a disc-shaped ceramic capacitor dielectric material, and the preparation method includes the following steps:

[0052] Weigh a certain mass of barium titanate, and add 1.0 wt% of Nb based on the mass of barium titanate2 O 5 and Dy 2 O 3 A mixed powder of O and Dy, and a silica sol solution. Among them, silicon dioxide in the silica sol solution accounts for 30 wt% of the total mass. In the added silica sol solution, the mass of silicon dioxide is 2.0 wt% of the mass of barium titanate. After mixing the above three components, granulating, and pressing under a pressure of 200 Mpa, a green body with a diameter of 10 mm and a thickness of 2 mm is obtained. Then, it is sintered by heating to 1300 °C at a rate of 4.5 °C / min and holding for 1.8 h. The total time of the heating process and the holding process during sintering is 6.6 h, and a ceramic capacitor dielectric material is obtained.

[0053] Example 6

[0054] This example provides a method for preparing a disk ceramic capacitor dielectric material. The difference between this preparation method and that of Example 1 is that the mass of silicon dioxide in the added silica sol solution is 0.005 wt% of the mass of barium titanate, and the rest of the preparation methods and parameters are the same as those in Example 1.

[0055] Example 7

[0056] This example provides a method for preparing a disk ceramic capacitor dielectric material. The difference between this preparation method and that of Example 1 is that the mass of silicon dioxide in the added silica sol solution is 2.5 wt% of the mass of barium titanate, and the rest of the preparation methods and parameters are the same as those in Example 1.

[0057] Example 8

[0058] This example provides a method for preparing a disk ceramic capacitor dielectric material. The difference between this preparation method and that of Example 1 is that the holding time is 5 h, and the total time of the heating and holding processes during sintering is 9.2 h. The rest of the preparation methods and parameters are the same as those in Example 1.

[0059] Comparative Example 1

[0060] This comparative example provides a method for preparing a disk ceramic capacitor dielectric material, which includes the following steps:

[0061] Weigh a certain mass of barium titanate, and add Nb which is 1.5 wt% of the mass of barium titanate 2 O 5 and Dy 2 O 3The mixed powder, silica powder with a mass of 0.2 wt% of barium titanate, and an aqueous solution of polyvinyl alcohol (PVA) with a concentration of 5 wt% and a mass of 20 wt% of barium titanate. After mixing and granulating the above materials, they are pressed under a pressure of 300 MPa to obtain a green body with a diameter of 10 mm and a thickness of 2 mm. Then, it is heated to 300 °C at a rate of 2 °C / min and held for 3 h, then heated to 550 °C at a rate of 2 °C / min and held for 2 h. Subsequently, it is heated to 1250 °C at a rate of 5 °C / min for sintering and held for 2 h. The total time of the heating process and the holding process during sintering is 14 h, and a disk-type ceramic capacitor dielectric material is obtained.

[0062] Figure 1 Figure 4 shows the surface SEM image of the disk-type ceramic capacitor dielectric material prepared in Example 1 of the present invention. Figure 2 Figure 6 shows the surface SEM image of the disk-type ceramic capacitor dielectric material prepared in Comparative Example 1 of the present invention. As can be seen from the figure, at the same magnification, the surface of the disk-type ceramic capacitor dielectric material in Example 1 is dense and no defects such as pores are generated, while there are a large number of pores on the surface of the disk-type ceramic capacitor dielectric material in Comparative Example 1.

[0063] The disk-type ceramic capacitor dielectric materials prepared in Examples 1-8 and Comparative Example 1 are tested for density, dielectric constant, dielectric loss, resistivity, and grain size. Grain size test: It is carried out according to the conditions and parameters in ISO13383-1:2012 "Fine Ceramics (Advanced Ceramics, Advanced Technical Ceramics). Microstructural Features - Part 1: Determination of Grain Size and Particle Size Distribution".

[0064] The specific test results are shown in Table 1.

[0065] Table 1

[0066] Item <![CDATA[Density (g / cm 3 )]]> Dielectric loss Dielectric constant Resistivity (Ω·m) Grain size (nm) Example 1 5.95 0.0038 3050 750 578 Example 2 5.93 0.0053 2910 580 794 Example 3 5.92 0.0035 2955 980 692 Example 4 5.93 0.0075 3100 725 922 Example 5 5.94 0.0056 2800 780 965 Example 6 5.93 0.0072 2746 579 1134 Example 7 5.92 0.0064 2776 885 860 Example 8 5.95 0.0070 2671 662 1082 Comparative Example 1 5.88 0.0127 2998 482 1356

[0067] It can be seen from the test results that:

[0068] (1) It can be seen from Examples 1 to 5 that the present invention uses silica sol as both the silicon source of the silica additive and the binder for granulation, and combined with the sintering process, a disk-type ceramic capacitor dielectric material with better overall performance can be prepared in a short time, and the density, dielectric constant, dielectric loss, resistivity, and grain size are all within a better range.

[0069] (2) It can be seen from Example 1 and Examples 6 - 7 that by further regulating the mass of silicon dioxide in the added silica sol solution, the present invention can, firstly, better function as a granulation binder, avoiding uneven granulation and thus affecting the preparation of the later green body; secondly, it can better serve as a silicon source to further regulate the sintering temperature, avoiding the change of the internal microstructure of the material caused by excessive addition, the excessive increase in the content of the grain boundary phase, which leads to a slight decrease in the overall performance of the material, and also avoiding that due to too little addition, the silica distributed at the grain boundaries is not sufficient to form an effective hindrance, the grain boundary migration resistance is small, the grain size is easily too large, and it cannot play the role of refining the grains, thus resulting in an increase in the dielectric loss and a decrease in the dielectric constant of the dielectric material of the wafer-type ceramic capacitor. At the same time, too little addition will also cause some dielectric materials of the wafer-type ceramic capacitor to be loose and the edges to fall off, with a low yield rate.

[0070] (3) It can be seen from Example 1 and Example 8 that during the regulation of the sintering process of the present invention, when the total time of the heating process and the heat preservation process is within 5.5 h - 6.7 h, a wafer-type ceramic capacitor dielectric material with better performance can be prepared. If the heat preservation time is further increased, it will not further improve the performance of the wafer-type ceramic capacitor dielectric material. Instead, it will cause grain growth, a decrease in the dielectric constant, a decrease in the insulation performance (low resistivity), a decrease in the breakdown resistance, and also increase the production time and cost, reducing the production efficiency.

[0071] (3) It can be seen from Example 1 and Comparative Example 1 that the present invention uses the silica sol solution as both the silicon source of the silicon dioxide additive and the binder for granulation, and combined with the sintering process, the prepared wafer-type ceramic capacitor dielectric material has better density, lower dielectric loss, and higher resistivity and dielectric constant. When using the traditional powdered silicon dioxide additive and adding an organic binder during granulation, it is impossible to prepare a wafer-type ceramic capacitor dielectric material within a short sintering time. During its sintering process, sintering is carried out at the same temperature, and the total duration of heating and heat preservation exceeds twice the duration of Example 1. Moreover, the overall performance of the wafer-type ceramic capacitor dielectric material prepared in Comparative Example 1 is also significantly reduced.

[0072] In summary, in the present invention, silica sol liquid is added to the formulation system, replacing the traditional powdery silica additive and the organic binder added during the granulation process. This greatly reduces the debinding time during sintering, and the silica sol liquid can serve as the silicon source of the silica additive. While reducing the sintering temperature of barium titanate, it can further improve the density of the dielectric material of the wafer-type ceramic capacitor, reduce the generation of pores, lower the dielectric loss, and increase the resistivity and dielectric constant. This preparation method can greatly improve production efficiency and reduce costs, and at the same time can further enhance the product performance of the dielectric material of the wafer-type ceramic capacitor.

[0073] The applicant declares that the above description is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by any person skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A method for preparing a disc-type ceramic capacitor dielectric material, characterized in that: The preparation method comprises the following steps: Barium titanate, rare earth oxide additive and silica sol are mixed, granulated and pressed to obtain a green body, and the green body is sintered to obtain a disc-type ceramic capacitor dielectric material.

2. The preparation method according to claim 1, characterized in that: The silica sol solution includes an acidic silica sol solution or a neutral silica sol solution; Preferably, the silica sol solution comprises silicon dioxide and an aqueous solution; Preferably, in the silica sol solution, the silicon dioxide accounts for ≥25wt% of the total mass of the silica sol solution.

3. The preparation method according to claim 2, characterized in that: The amount of the silica sol added is based on the mass of the silicon dioxide, and the mass of the silicon dioxide in the added silica sol is 0.01wt%-2.0wt% of the mass of the barium titanate; Preferably, the added amount of the rare earth oxide additive is 0.1wt%-1.5wt% of the mass of the barium titanate.

4. The preparation method according to any one of claims 1 to 3, characterized in that The heating rate of the sintering is 4.5°C / min-5.5°C / min; Preferably, the sintering temperature is 1200°C-1300°C.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The sintering holding time is 1.8h-2.2h; Preferably, the total time of the heating process and the heat preservation process of the sintering is 5.5h-6.7h.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The pressing pressure is 90MPa-800MPa, preferably 200MPa-300MPa.

7. The preparation method according to claim 1, characterized in that: The preparation method comprises the following steps: The barium titanate, the rare earth oxide additive and the silica sol solution are mixed and granulated, and then pressed at a pressure of 200MPa-300MPa to obtain a green body, and the green body is sintered at a rate of 4.5℃ / min-5.5℃ / min to 1200℃-1300℃, and the green body is kept warm for 1.8h-2.2h. The total time of the sintering heating process and the heat preservation process is 5.5h-6.7h, and the disc-type ceramic capacitor dielectric material is obtained; The silica sol solution includes silicon dioxide and an aqueous solution; the silicon dioxide accounts for ≥25wt% of the total mass of the silica sol solution; the amount of the silica sol solution added is based on the mass of the silicon dioxide, and the mass of the silicon dioxide added to the silica sol solution is 0.01wt%-2.0wt% of the mass of the barium titanate; the amount of the rare earth oxide additive added is 0.1wt%-1.5wt% of the mass of the barium titanate.

8. A disc-type ceramic capacitor dielectric material, characterized in that: The disc-type ceramic capacitor dielectric material is prepared according to the preparation method according to any one of claims 1-7.

9. The disc-type ceramic capacitor dielectric material according to claim 8, characterized in that: The grain size of the disc-type ceramic capacitor dielectric material is 550nm-1150nm.

10. An application of a disc-type ceramic capacitor dielectric material, characterized in that: The disc-type ceramic capacitor dielectric material according to claim 8 or 9 is used in electronic components.

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