A borosilicate glass composition, method of making and use thereof

Abstract

The application provides a borosilicate glass composition and a preparation method and application thereof, the borosilicate glass composition comprises SiO2, B2O3, CaO, MgO, CeO2, TiO2, Nb2O5, CoO and MnO in terms of oxides.The borosilicate glass composition provided by the application is matched with a ceramic matrix and is conducive to low-temperature densification sintering through synergistic effect of multiple functional oxides;the dielectric ceramic composition formed by the glass composition and BaTiO3 can inhibit abnormal grain growth through synergistic effect of donor / acceptor co-doping, and after glue removal, sintering and crystallization, a multilayer core-shell structure is formed, so that high dielectric constant, low dielectric loss and high breakdown field strength are maintained at the same time, the comprehensive performance is excellent, and the borosilicate glass composition is suitable for preparing ceramic capacitor electronic components.

Description

Technical Field

[0001] This invention belongs to the field of ceramic materials technology, and relates to a borosilicate glass composition, its preparation method, and its application. Background Technology

[0002] Barium titanate (BaTiO3)-based ceramic materials are widely used as dielectric layer materials for multilayer ceramic capacitors (MLCCs) due to their excellent properties such as high dielectric constant and low dielectric loss. As electronic components develop towards miniaturization, large capacity, and high reliability, higher requirements are placed on the comprehensive performance of dielectric materials: not only are high dielectric constant and low dielectric loss necessary, but also high breakdown field strength is required to ensure the device's withstand voltage performance.

[0003] However, pure barium titanate materials have inherent defects: on the one hand, the dielectric constant varies greatly with temperature, resulting in poor temperature stability; on the other hand, the dielectric loss is high, and the breakdown field strength is low, making it difficult to simultaneously meet the requirements of high energy density and high-temperature stability. Therefore, it is necessary to modify the barium titanate matrix by adding various additives to improve its dielectric properties and microstructure.

[0004] Existing technologies have disclosed technical solutions for improving the performance of barium titanate ceramics by adding various additives. For example, CN102718477A discloses a high dielectric constant X8R type MLCC dielectric material, using barium titanate as the base material, and adding niobium cobalt compounds, titanium bismuth sodium compounds, zirconium calcium compounds, glass powder, rare earth oxides, and manganese carbonate. By adding appropriate amounts of manganese carbonate, rare earth elements, and zirconium calcium compounds, the insulation resistivity and reduction resistance of the material are improved. CN118039353A discloses a reduction-resistant high dielectric X7R dielectric ceramic material, using barium titanate powder as the base material, and adding dopants with reduction resistance (including MgO, MnO2, NiO, Y2O3, Co2O3, ZrO2, etc.), impurities that cause lattice distortion (including Y2O3, Sm2O3, La2O3, Nd2O3, Dy2O3, Ho2O3, CeO2, etc.), and a glass phase.

[0005] Although existing technologies have modified barium titanate ceramics with various additives and achieved certain performance improvements, the above-mentioned technical solutions still have the following shortcomings: First, although some technical solutions have a high dielectric constant, the dielectric loss also increases accordingly, making it difficult to achieve low dielectric loss while maintaining a high dielectric constant; Second, although some technical solutions have improved the breakdown field strength, the dielectric constant has decreased significantly, making it difficult to achieve a balance between high dielectric constant and high breakdown field strength; Third, existing technologies usually improve performance through complex combinations of various additives, but the interaction mechanisms between the additives are complex and difficult to regulate systematically, which limits further optimization of overall performance.

[0006] Therefore, how to achieve high dielectric constant and low dielectric loss while maintaining high breakdown field strength in barium titanate ceramic materials through reasonable additive design is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a borosilicate glass composition, its preparation method, and its applications. The borosilicate glass composition provided by this invention exhibits a stable network structure, with multiple functional oxides working synergistically to ensure good compatibility with the ceramic matrix and facilitate low-temperature densification sintering. The dielectric ceramic composition formed by this glass composition and BaTiO3, through donor / acceptor co-doping synergy, can suppress abnormal grain growth. After debinding sintering and crystallization, a multilayer core-shell structure is formed, thereby maintaining a high dielectric constant while also possessing low dielectric loss and high breakdown field strength. This results in excellent overall performance, making it suitable for electronic components such as MLCCs.

[0008] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a borosilicate glass composition, wherein the elements contained in the borosilicate glass composition, calculated as oxides, include SiO2, B2O3, CaO, MgO, CeO2, TiO2, Nb2O5, CoO and MnO.

[0009] In this invention, the borosilicate glass composition exhibits a moderate softening temperature and good fluidity, facilitating uniform mixing with various ceramic materials and achieving densification sintering at relatively low temperatures. The components work synergistically to enhance the overall performance of the glass composition and its composites: SiO2 and B2O3 form the main network framework of the glass, ensuring its thermal and chemical stability; the addition of CaO and MgO adjusts the viscosity and thermal expansion coefficient of the glass, improving thermal compatibility with the ceramic matrix and reducing sintering stress; CeO2, as a rare earth oxide, diffuses into the ceramic lattice during sintering, playing a beneficial doping role; the coexistence of TiO2 and Nb2O5 helps optimize the dielectric response of the ceramic material; CoO and MnO reduce ceramic leakage current, increase resistivity, and decrease dielectric loss. This rational combination and synergistic effect of the various components allows the final dielectric ceramic material to maintain a high dielectric constant while effectively reducing dielectric loss and significantly increasing breakdown field strength, achieving synergistic optimization of the three properties. The glass composition provided by this invention can be used as a functional glass material or sintering aid in fields such as electronic ceramics, structural ceramics, and microcrystalline glass.

[0010] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0011] Preferably, the mass ratio of SiO2, B2O3, CaO, MgO, CeO2, TiO2, Nb2O5, CoO and MnO is (40~45):(25~30):(10~12):(6~10):(0.5~1):(3~4):(3~8):(0.3~0.8):(0.5~1), for example 40:25:10:6:0.5:3:3:0.3:0.5, 40:30:10:6:0.5:4:8:0.5:1, 43:25:10:10:0.5:4:6:0.5:1, 43:28:11:8:0.8:3.5:6:0.5:0.8 or 45:30:12:10:1:4:8:0.8:1, etc.

[0012] Preferably, the average particle size of the borosilicate glass composition is ≤1μm, more preferably 200nm~500nm, such as 200nm, 250nm, 300nm, 350nm, 400nm, 450nm or 500nm.

[0013] In a second aspect, the present invention provides a method for preparing a borosilicate glass composition as described in the first aspect, the method comprising: mixing SiO2, H3BO3, CaCO3, MgCO3, CeO2, TiO2, Nb2O5, CoO and MnO to obtain a mixture, and then sequentially melting and quenching the mixture to obtain the borosilicate glass composition.

[0014] Preferably, the mixing method includes grinding.

[0015] Preferably, the melting temperature is 1430℃~1530℃, such as 1430℃, 1450℃, 1470℃, 1500℃ or 1530℃, and the melting time is 70min~120min, such as 70min, 80min, 90min, 100min, 110min or 120min.

[0016] Preferably, the quenching method includes water quenching.

[0017] Preferably, the quenched product is subjected to ball milling, sand milling and spray drying in sequence to obtain the borosilicate glass composition.

[0018] Thirdly, the present invention provides a dielectric ceramic composition comprising BaTiO3 and a borosilicate glass composition as described in the first aspect, wherein the mass ratio of BaTiO3 to the borosilicate glass composition is 100:(1~3), for example 100:1, 100:1.5, 100:2, 100:2.5 or 100:3, etc.

[0019] In this invention, if the glass content is too low, insufficient liquid phase formation will occur, hindering sintering densification, increasing the sintering temperature, and resulting in high dielectric loss, poor temperature coefficient of ceramic capacitors, and decreased breakdown field strength. If the glass content is too high, the low dielectric constant glass phase will dilute the BaTiO3 main phase, leading to a decrease in dielectric constant. Therefore, the ratio of the two needs to be controlled within the above-mentioned preferred range to achieve a balance between high density, high dielectric constant, low loss, and high breakdown field strength.

[0020] Fourthly, the present invention provides a method for preparing the dielectric ceramic composition as described in the third aspect, the method comprising: ball milling and mixing BaTiO3 and borosilicate glass composition according to a target mass ratio, and obtaining the dielectric ceramic composition by spray granulation.

[0021] Fifthly, the present invention provides a dielectric ceramic sintered body, which is obtained by debinding, sintering and crystallization treatment of the dielectric ceramic composition as described in the third aspect; The dielectric ceramic sintered body includes a plurality of dielectric grains, each dielectric grain having a core and a first shell, a second shell, and a third shell sequentially covering the surface of the core; the core includes BaTiO3, the first shell includes BaTiO3 doped with Nb and Ce, the second shell includes BaTiO3 doped with Nb, Co, and Mn, and the third shell includes a CaO-MgO-B2O3-SiO2 glass.

[0022] In this invention, the dielectric ceramic composition undergoes sequential crystallization during sintering: First, Ti- and Nb-based composite oxides preferentially precipitate from the glass phase and adhere to the surface of BaTiO3 particles, then gradually diffuse and dope into the BaTiO3 lattice to form an Nb-doped barium titanate layer; second, rare earth Ce oxides precipitate and participate in the solid solution reaction; next, Co and Mn elements enter the crystalline phase in solid solution form, forming an Nb-Co-Mn co-doped BaTiO3 layer together with Nb and Ti; finally, the remaining glass phase is enriched as calcium magnesium borosilicate, which coats the outermost layer. As crystallization proceeds, the components sequentially form a multi-layered core-shell structure from the inside out, consisting of a BaTiO3 core, an intermediate layer of Nb and Ce-doped BaTiO3, and an outer shell of CaO-MgO-B2O3-SiO2 glass.

[0023] Furthermore, it should be emphasized that compared to directly mixing the functional components (such as CeO2, TiO2, Nb2O5, CoO, MnO, etc.), the glass substrate (such as SiO2, B2O3, CaO, MgO, etc.) and BaTiO3, the present invention first melts the functional components at high temperature into a glass composition and then mixes it with BaTiO3. The production process is simpler and suitable for industrial production.

[0024] Preferably, the sintering temperature is 1200℃~1300℃, such as 1200℃, 1220℃, 1250℃, 1280℃ or 1300℃, and the time is 2h~3h, such as 2h, 2.2h, 2.5h, 2.8h or 3h.

[0025] The crystallization treatment is performed at a temperature of 1000℃~1100℃, such as 1000℃, 1020℃, 1050℃, 1070℃ or 1100℃, and for a time of 3h~8h, such as 3h, 4h, 5h, 6h, 7h or 8h.

[0026] It is understood that the dielectric ceramic composition is pressed into shape prior to the debinding and sintering.

[0027] In a sixth aspect, the present invention provides a ceramic capacitor comprising a dielectric ceramic sintered body and electrodes as described in the fifth aspect.

[0028] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0029] Compared with the prior art, the present invention has the following beneficial effects: (1) The borosilicate glass composition has a stable network structure and can be well matched with the ceramic matrix, which is beneficial to low-temperature densification sintering; (2) The glass composition in the dielectric ceramic composition works synergistically with BaTiO3 to promote donor / acceptor co-doping, reduce sintering temperature, and inhibit abnormal grain growth. After debinding sintering and crystallization, a multilayer core-shell structure can be formed. While maintaining a high dielectric constant, it has low dielectric loss and high breakdown field strength, with excellent comprehensive performance, and is suitable for electronic components such as MLCC. (3) The preparation method provided by the present invention is simple and convenient, and easy to mass-produce. Attached Figure Description

[0030] Figure 1 This is a TEM image of the interior of a ceramic cross-section provided in Application Example 1.1.

[0031] Figure 2This is an SEM image of the ceramic sheet surface provided in Application Example 1.1.

[0032] Figure 3 This is a microscope image of the ceramic slide provided in Example 1.1. Detailed Implementation

[0033] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0034] "The scope of this invention can be defined by a lower limit and an upper limit. The selected lower limit and upper limit define the boundary of a specific range. The range defined in this way can be defined by the inclusion or exclusion of endpoints. Any endpoint can be independently selected for inclusion or exclusion, and all lower limit and upper limit values ​​can be arbitrarily combined to form a new range. That is, any lower limit value can be combined with any upper limit value to form an effective range. For example, if the ranges of 60~120 and 80~110 are listed for specific parameters, it should be understood that the ranges of 60~110 and 80~120 also fall within the scope of this invention. In addition, if the minimum range values ​​1 and 2 are listed, and the maximum range values ​​3, 4 and 5 are also listed, then 1~3, 1~4, and 2~3, 1~4, 2~5 ... All ranges from 1 to 5, 2 to 3, 2 to 4, and 2 to 5 fall within the scope of this invention. In this invention, the numerical range "a to b" represents a shortened representation of any combination of real numbers between a and b, where both a and b are real numbers. For example, the numerical range "0 to 5" indicates that all real numbers between 0 and 5 have been fully listed in this document; "0 to 5" is merely a shortened representation of this numerical combination. When a parameter is expressed as an integer ≥ 2, it is equivalent to listing positive integers that meet the requirements, such as 2, 3, 4, 5, 6, 7, 8, 9, and 10. When a parameter is expressed as an integer selected from "2 to 10", it is equivalent to listing any integer among 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0035] In this invention, "a combination of at least two" refers to a quantity greater than or equal to 2 unless otherwise specified. For example, "any one or a combination of at least two" means that any one of the listed items can be selected, or a combination of at least two of the listed items formed in a manner that does not conflict and enables the implementation of this invention. In this invention, unless otherwise specified, the features or solutions corresponding to "and / or" cover any one of two or more related listed items, as well as any and all combinations of the related listed items. The arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" means a set consisting of A, B, and combinations of A and B, where "containing A and / or B" can be understood, depending on the context of the statement, as containing A, containing B, or simultaneously containing both A and B. In this invention, "optional" means that the corresponding feature, component, step or solution is not necessary, that is, it is selected from either "with" or "without". If there are multiple "optional" limitations in a technical solution, unless otherwise specified and there is no technical conflict or mutual constraint, each "optional" limitation is independent and does not affect the others.

[0036] In this invention, technical features or solutions described using open-ended terms such as "comprising" or "including" do not exclude additional non-conflicting elements beyond the listed elements unless otherwise specified. They are considered to disclose both closed-ended features or solutions consisting solely of the listed elements and open-ended features or solutions that may include additional non-conflicting elements beyond the listed elements. For example, if A includes a1, a2, and a3, unless otherwise specified, this means that A can consist only of a1, a2, and a3, or it can include other non-conflicting elements based on a1, a2, and a3. This corresponds to the disclosure of technical solutions such as "A consists of a1, a2, and a3," "A is selected from a1, a2, and a3," and "A not only includes a1, a2, and a3, but may also include other non-conflicting elements." All embodiments and optional embodiments of this invention, unless otherwise specified and without technical conflict, can be combined to form new technical solutions, and such combinations fall within the scope of this invention. The term "embodiment" as used in this invention means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of the invention. The appearance of this phrase in various locations throughout the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described in this invention can be combined with other embodiments that do not conflict with the technology. The ordinal numbers "first," "second," "third," and "fourth," etc., used in the expressions "first aspect," "second aspect," "third aspect," and "fourth aspect" in this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly specifying the importance or quantity of the indicated technical features. They serve only as a non-exhaustive enumeration and do not constitute a closed limitation on quantity.

[0037] In this invention, the order in which the steps are written in the methods described in each embodiment does not imply a strict execution order. The actual execution order of each step should be determined based on its function and possible internal logic. Unless otherwise specified, all steps of this invention can be executed in the order they are written, or in any order without technical conflict. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) executed sequentially, or it may include steps (b) and (a) executed sequentially. If the method also includes step (c), then step (c) can be added to the method in any order without conflict, including but not limited to the execution order of steps (a), (b), and (c), steps (a), (c), and (b), steps (c), (a), and (b), etc.

[0038] The term "embodiment" as used in this invention means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0039] In this invention, "room temperature" generally refers to 4℃~35℃, and can refer to 20℃±5℃. In some embodiments of this invention, room temperature refers to 20℃~30℃.

[0040] Example 1 This embodiment provides a dielectric ceramic composition comprising BaTiO3 and a borosilicate glass composition (mass ratio 100:2). The borosilicate glass composition comprises SiO2, B2O3, CaO, MgO, CeO2, TiO2, Nb2O5, CoO, and MnO, with a mass ratio of 43:25:10:10:0.5:4:6:0.5:1. The preparation method is as follows: (1) SiO2, H3BO3, CaCO3, MgCO3, CeO2, TiO2, Nb2O5, CoO and MnO are ground and mixed to obtain a mixed powder. The mixed powder is placed in a corundum crucible and pre-calcined at 500℃ for 1 hour to remove moisture and completely decompose the carbonates. Then it is melted at 1480℃ for 90 minutes, and stirred multiple times during the holding period to obtain a clear and homogeneous melt. The melt is poured into deionized water for water quenching to obtain glass frit. The glass frit is ball-milled, sand-milled and spray-dried to obtain the borosilicate glass composition. (2) The BaTiO3 and borosilicate glass composition were ball-milled at a mass ratio of 100:2 and then spray-granulated to obtain the dielectric ceramic composition.

[0041] Example 2 This embodiment provides a dielectric ceramic composition comprising BaTiO3 and a borosilicate glass composition (mass ratio 100:2). The borosilicate glass composition comprises SiO2, B2O3, CaO, MgO, CeO2, TiO2, Nb2O5, CoO, and MnO, with a mass ratio of 43:25:10:10:0.5:4:6:0.5:1. The preparation method is as follows: (1) SiO2, H3BO3, CaCO3, MgCO3, CeO2, TiO2, Nb2O5, CoO and MnO are ground and mixed to obtain a mixed powder. The mixed powder is placed in a corundum crucible and pre-calcined at 450°C for 1.5 h to remove moisture and completely decompose the carbonates. Then it is melted at 1430°C for 110 min, and stirred multiple times during the holding period to obtain a clear and homogeneous melt. The melt is poured into deionized water for water quenching to obtain a glass material. The glass material is ball-milled, sand-milled and spray-dried to obtain the borosilicate glass composition. (2) The BaTiO3 and borosilicate glass composition were ball-milled at a mass ratio of 100:2 and then spray-granulated to obtain the dielectric ceramic composition.

[0042] Example 3 This embodiment provides a dielectric ceramic composition comprising BaTiO3 and a borosilicate glass composition (mass ratio 100:2). The borosilicate glass composition comprises SiO2, B2O3, CaO, MgO, CeO2, TiO2, Nb2O5, CoO, and MnO in a mass ratio of 40:30:10:6:0.5:4:8:0.5:1. The preparation method is as follows: (1) SiO2, H3BO3, CaCO3, MgCO3, CeO2, TiO2, Nb2O5, CoO and MnO were ground and mixed according to the target molar ratio to obtain a mixed powder. The mixed powder was placed in an alumina crucible and pre-fired at 550°C for 30 min to remove moisture and completely decompose the carbonates. Then it was melted at 1530°C for 70 min, and stirred multiple times during the holding period to obtain a clear and homogeneous melt. The melt was poured into deionized water for water quenching to obtain a glass material. The glass material was ball-milled, sand-milled and spray-dried to obtain the borosilicate glass composition.

[0043] (2) The BaTiO3 and borosilicate glass composition were ball-milled at a mass ratio of 100:2 and then spray-granulated to obtain the dielectric ceramic composition.

[0044] Example 4 The difference between this embodiment and Embodiment 1 is that the mass ratio of BaTiO3 to borosilicate glass composition is 100:1; The remaining preparation methods and parameters are consistent with those in Example 1.

[0045] Example 5 The difference between this embodiment and Embodiment 1 is that the mass ratio of BaTiO3 to borosilicate glass composition is 100:3; The remaining preparation methods and parameters are consistent with those in Example 1.

[0046] Example 6 The difference between this embodiment and Embodiment 1 is that the mass ratio of SiO2, B2O3, CaO, MgO, CeO2, TiO2, Nb2O5, CoO and MnO is 43:25:5.5:10:0.5:4:10:1:1; The remaining preparation methods and parameters are consistent with those in Example 1.

[0047] Example 7 The difference between this embodiment and Embodiment 1 is that the mass ratio of BaTiO3 to borosilicate glass composition is 100:4; The remaining preparation methods and parameters are consistent with those in Example 1.

[0048] Comparative Example 1 The difference between this comparative example and Example 1 is that the borosilicate glass composition does not contain CoO, while the proportions of the remaining components remain unchanged. The remaining preparation methods and parameters are consistent with those in Example 1.

[0049] Comparative Example 2 The difference between this comparative example and Example 1 is that the dielectric ceramic composition includes BaTiO3, CeO2, TiO2, Nb2O5, MnO and a borosilicate glass composition (excluding CeO2, TiO2, Nb2O5 and MnO), and the proportion of each component in the overall dielectric ceramic composition remains unchanged. The remaining preparation methods and parameters are consistent with those in Example 1.

[0050] Application Example 1.1 This application example provides a dielectric ceramic sintered body (ceramic sheet), prepared by the following method: The dielectric ceramic composition provided in Example 1 was pressed into shape, first debinded at 300°C for 2 hours, then sintered at 1240°C for 3 hours, then cooled to 1050°C for 8 hours to slowly crystallize, and finally cooled to room temperature in the furnace to obtain a ceramic sheet with a diameter of 10 mm and a thickness of 4 mm.

[0051] Application Example 1.2 The difference between this application example and application example 1.1 is that the binder is first removed at 200°C for 2 hours, then sintered at 1245°C for 2 hours, then cooled to 1050°C for 5 hours to slowly crystallize, and finally cooled to room temperature with the furnace. The remaining preparation methods and parameters are consistent with those in Application Example 1.1.

[0052] Application Example 1.3 The difference between this application example and application example 1.1 is that the binder is first removed at 400°C for 2 hours, then sintered at 1250°C for 2 hours, then cooled to 1100°C for 5 hours to slowly crystallize, and finally cooled to room temperature with the furnace. The remaining preparation methods and parameters are consistent with those in Application Example 1.1.

[0053] Application Example 2-3 The difference between Application Example 2-3 and Application Example 1.1 is that they are prepared using the dielectric ceramic composition provided in Example 2-3, respectively. The remaining preparation methods and parameters are consistent with those in Application Example 1.1.

[0054] Application Example 4 The difference between this application example and application example 1.1 is that the dielectric ceramic composition provided in example 4 is pressed into shape, first debinded at 300°C for 2 hours, then sintered at 1250°C for 2 hours, then cooled to 1050°C for 3 hours to slowly crystallize, and finally cooled to room temperature in the furnace. The remaining preparation methods and parameters are consistent with those in Application Example 1.1.

[0055] Application Example 5 The difference between this application example and application example 1.1 is that the dielectric ceramic composition provided in Example 5 is pressed into shape, first debinded at 300°C for 2 hours, then sintered at 1220°C for 2 hours, then cooled to 1050°C for 8 hours to slowly crystallize, and finally cooled to room temperature in the furnace. The remaining preparation methods and parameters are consistent with those in Application Example 1.1.

[0056] Application Example 6-7 The difference between Application Examples 6-7 and Application Example 1.1 is that they are prepared using the dielectric ceramic compositions provided in Examples 6-7, respectively. The remaining preparation methods and parameters are consistent with those in Application Example 1.1.

[0057] Comparative application examples 1-2 The difference between Comparative Example 1-2 and Comparative Example 1.1 is that they are prepared using the dielectric ceramic compositions provided in Comparative Example 1-2, respectively. The remaining preparation methods and parameters are consistent with those in Application Example 1.1.

[0058] Performance testing The dielectric ceramic sintered body obtained in corresponding use case 1.1 was characterized by TEM, SEM, and microscopy, and the results are as follows: Figures 1-3 As shown.

[0059] Silver paste was printed on the surface of the dielectric ceramic sintered bodies prepared in Application Examples 1-7 and Comparative Application Examples 1-2, respectively. After sintering, ceramic capacitor silver sheets were obtained, and their dielectric properties were then tested. The results are shown in Table 1.

[0060] Table 1 Depend on Figure 1It can be seen that, using the dielectric ceramic composition provided by the present invention, after debinding, sintering and crystallization treatment, a dielectric ceramic sintered body with a multi-layer core-shell structure was successfully obtained. Figure 2 , Figure 3 The results show that the sintered ceramic surface exhibits a distinct glassy phase and lacks pores. This is likely due to prolonged crystallization, forming glass-like anchor points that effectively fill the ceramic pores, thereby increasing the ceramic's breakdown field strength.

[0061] As can be seen from the comparison of the data of Application Example 1.1 and Comparative Application Example 1 in Table 1, the components in the glass composition work synergistically and are indispensable. At the same time, as can be seen from the comparison of the data of Application Example 1.1 and Comparative Application Example 2, only by pre-melting each functional component into the glass composition can a dielectric ceramic sintered body with a specific structure be formed, thereby achieving a synergistic improvement in high dielectric constant, low dielectric loss and high breakdown field strength. However, if the functional components, glass matrix material and barium titanate are directly mixed, it is difficult to obtain the ideal microstructure and the dielectric properties are significantly degraded.

[0062] A comparison of the data from Application Example 1.1 with Application Examples 1.2 and 1.3 in Table 1 shows that the dielectric properties can be controlled by adjusting the temperature or time of the debinding sintering and crystallization treatment.

[0063] A comparison of the data from Application Examples 1.1 and 2-7 in Table 1 shows that, within the preferred scope of this invention, changing the proportions of the components in the glass composition, or changing the proportions of the glass composition and BaTiO3 in the dielectric ceramic composition, allows for flexible control and emphasis on the three properties while maintaining high dielectric constant, low dielectric loss, and high breakdown field strength. In practical applications, the appropriate component proportions can be selected according to specific performance requirements. However, it should be noted that if the preferred scope of this invention is exceeded, it is difficult to simultaneously achieve all three properties, often resulting in an improvement in one property at the expense of others.

[0064] The applicant declares that the above description is only a specific embodiment 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 those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A borosilicate glass composition, characterized in that, The borosilicate glass composition contains elements, in terms of oxides, including SiO2, B2O3, CaO, MgO, CeO2, TiO2, Nb2O5, CoO and MnO.

2. The borosilicate glass composition according to claim 1, characterized in that, The mass ratio of SiO2, B2O3, CaO, MgO, CeO2, TiO2, Nb2O5, CoO and MnO is (40~45):(25~30):(10~12):(6~10):(0.5~1):(3~4):(3~8):(0.3~0.8):(0.5~1).

3. The borosilicate glass composition according to claim 1 or 2, characterized in that, The average particle size of the borosilicate glass composition is ≤1 μm.

4. A method for preparing a borosilicate glass composition according to any one of claims 1-3, characterized in that, The preparation method includes: mixing SiO2, H3BO3, CaCO3, MgCO3, CeO2, TiO2, Nb2O5, CoO and MnO to obtain a mixture, and then sequentially melting and quenching the mixture to obtain the borosilicate glass composition.

5. The preparation method according to claim 4, characterized in that, The melting temperature is 1430℃~1530℃, and the melting time is 70min~120min.

6. The preparation method according to claim 4 or 5, characterized in that, The quenched product was subjected to ball milling, sand milling and spray drying in sequence to obtain the borosilicate glass composition.

7. A dielectric ceramic composition, characterized in that, The dielectric ceramic composition comprises BaTiO3 and the borosilicate glass composition as described in any one of claims 1-3, wherein the mass ratio of BaTiO3 to the borosilicate glass composition is 100:(1~3).

8. A dielectric ceramic sintered body, characterized in that, The dielectric ceramic sintered body is obtained by debinding, sintering and crystallization treatment of the dielectric ceramic composition as described in claim 7; The dielectric ceramic sintered body includes a plurality of dielectric grains, each dielectric grain having a core and a first shell, a second shell, and a third shell sequentially covering the surface of the core; the core includes BaTiO3, the first shell includes BaTiO3 doped with Nb and Ce, the second shell includes BaTiO3 doped with Nb, Co, and Mn, and the third shell includes a CaO-MgO-B2O3-SiO2 glass.

9. The dielectric ceramic sintered body according to claim 8, characterized in that, The sintering temperature is 1200℃~1300℃, and the time is 2h~3h; The crystallization treatment is performed at a temperature of 1000℃~1100℃ for 3h~8h.

10. A ceramic capacitor, characterized in that, The ceramic capacitor includes a dielectric ceramic sintered body and electrodes as described in claim 8 or 9.

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