A high-voltage ceramic capacitor dielectric material, a preparation method thereof and a ceramic capacitor

Abstract

This invention provides a high-voltage ceramic capacitor dielectric material, its preparation method, and a ceramic capacitor. The raw materials for preparing the high-voltage ceramic capacitor dielectric material include Ca-B-Si microcrystalline glass powder, which is prepared from CaCO3, B2O3, and SiO2. By introducing Ca-B-Si microcrystalline glass powder into the raw materials for preparing the high-voltage ceramic capacitor dielectric material, this invention utilizes the characteristics of Ca-B-Si microcrystalline glass powder to form a liquid phase that fills the grain boundaries and micropore defects of the main crystalline phase during sintering, while simultaneously precipitating a large number of uniformly distributed micrograins in situ. This significantly improves the ceramic density and breakdown field strength of the high-voltage ceramic capacitor dielectric material, effectively reduces the sintering temperature, and maintains the original high dielectric constant and low dielectric loss characteristics. Furthermore, the high-voltage ceramic capacitor dielectric material provided by this invention is a lead-free system, meeting the requirements of green environmental protection.

Description

Technical Field

[0001] This invention belongs to the field of ceramic capacitor technology, and relates to a high-voltage ceramic capacitor dielectric material, and more particularly to a high-voltage ceramic capacitor dielectric material, its preparation method, and a ceramic capacitor. Background Technology

[0002] With the rapid development of consumer electronics, new energy vehicles and other fields, ceramic capacitors are evolving towards miniaturization, high voltage and lead-free, and there is an urgent need for dielectric materials with low dielectric loss and simultaneously possessing lead-free environmental protection, high dielectric constant and high breakdown field strength.

[0003] Existing technologies often improve sintering performance by adding amorphous glass, but this leads to a significant decrease in dielectric constant and breakdown field strength. Existing microcrystalline glass modification technologies suffer from a mismatch between crystallization and sintering temperatures, resulting in limited breakdown improvement and significant dielectric loss. They also require sintering at high temperatures, leading to high energy consumption and easy deterioration of dielectric properties.

[0004] CN102531579A discloses a ceramic dielectric material and a ceramic capacitor. The ceramic dielectric material and its preparation method of this invention utilize Sr synthesized via a solid-state reaction method. 1-x Ca x Ti 1-y Si y O3 (where 0.05≤x≤0.35, 0.02≤y≤0.25) is the main crystalline phase material, and the main crystalline phase component accounts for 90%~96% of the composition of the dielectric material by mass percentage; then four or more of the following are added as modifiers: BaO, MgO, ZrO2, Nb2O5, MnO2, Y2O3, Al2O3, ZnO, B2O3, and R2O3 (R is at least one of Sm, Ho, and Dy), accounting for 10%~4% of the composition of the dielectric material by mass percentage.

[0005] CN1634800A discloses a high-frequency thermally stable ceramic dielectric material sintered at ultra-low temperatures, its preparation method, and a multilayer chip ceramic capacitor made from this material. The ceramic dielectric material disclosed in this document is a lead-free, environmentally friendly material, comprising the main component BaNd. 2+X Ti5O 14+1.5X (0.001≤X≤0.2) and auxiliary components B2O3, Al2O3, SiO2, CaO and ZnO, and may further include SnO and one or more compounds selected from K2O, ZrO2, Fe2O3 and MgO.

[0006] In summary, existing high-voltage ceramic capacitor dielectric materials all have certain defects, such as difficulty in achieving high breakdown field strength while simultaneously possessing high dielectric constant, low dielectric loss, and being lead-free and environmentally friendly. Therefore, developing and designing a new type of high-voltage ceramic capacitor dielectric material and its preparation method is crucial for ceramic capacitors. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a high-voltage ceramic capacitor dielectric material, its preparation method, and a ceramic capacitor. This invention introduces Ca-B-Si microcrystalline glass powder into the raw materials for preparing the high-voltage ceramic capacitor dielectric material. Utilizing the powder's properties during sintering—forming a liquid phase to fill grain boundaries and micropore defects in the main crystalline phase, and simultaneously precipitating a large number of uniformly distributed micrograins in situ—this significantly improves the ceramic density and breakdown field strength of the high-voltage ceramic capacitor dielectric material. Furthermore, it effectively reduces the sintering temperature while maintaining the original high dielectric constant and low dielectric loss characteristics. In addition, the high-voltage ceramic capacitor dielectric material provided by this invention is a lead-free system, meeting the requirements of green environmental protection.

[0008] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a high-voltage ceramic capacitor dielectric material, wherein the raw materials for preparing the high-voltage ceramic capacitor dielectric material include Ca-B-Si microcrystalline glass powder, and the raw materials for preparing the Ca-B-Si microcrystalline glass powder include CaCO3, B2O3 and SiO2.

[0009] This invention introduces Ca-B-Si microcrystalline glass powder into the raw materials for preparing high-voltage ceramic capacitor dielectric materials. Utilizing the powder's properties during sintering—forming a liquid phase to fill grain boundaries and micropore defects in the main crystalline phase, and simultaneously precipitating a large number of uniformly distributed micrograins in situ—this significantly improves the ceramic density and breakdown field strength of the high-voltage ceramic capacitor dielectric material. Furthermore, it effectively reduces the sintering temperature while maintaining the original high dielectric constant and low dielectric loss characteristics. In addition, the high-voltage ceramic capacitor dielectric material provided by this invention is a lead-free system, meeting the requirements of green environmental protection.

[0010] Preferably, based on the mass of the raw materials used to prepare the Ca-B-Si microcrystalline glass powder, the mass fraction of CaCO3 in the raw materials used to prepare the Ca-B-Si microcrystalline glass powder is 30wt%~40wt%, for example, it can be 30wt%, 31wt%, 32wt%, 33wt%, 34wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, or 40wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0011] Preferably, based on the mass of the raw materials used to prepare the Ca-B-Si microcrystalline glass powder, the mass fraction of B2O3 in the raw materials used to prepare the Ca-B-Si microcrystalline glass powder is 22wt%~30wt%, for example, it can be 22wt%, 23wt%, 24wt%, 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, or 30wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0012] Preferably, based on the mass of the raw materials used to prepare the Ca-B-Si microcrystalline glass powder, the mass fraction of SiO2 in the raw materials used to prepare the Ca-B-Si microcrystalline glass powder is 30wt% to 48wt%, for example, it can be 30wt%, 32wt%, 34wt%, 36wt%, 38wt%, 40wt%, 42wt%, 44wt%, 46wt%, or 48wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0013] Preferably, the raw materials for preparing the high-voltage ceramic capacitor dielectric material further include a main component, which includes barium titanate and strontium titanate in a molar ratio of Ba to Sr of (65~79):(21~35), for example, 65:35, 67:33, 69:31, 71:29, 73:27, 75:25, 77:23 or 79:21, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0014] Preferably, the raw materials for preparing the high-voltage ceramic capacitor dielectric material further include a first auxiliary component, which includes Bi2O3 and TiO2 in a molar ratio of 1:(1~3), for example, 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:2.2, 1:2.4, 1:2.6, 1:2.8 or 1:3, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0015] Preferably, the raw materials for preparing the high-voltage ceramic capacitor dielectric material further include a second auxiliary component, which includes Nd2O3 and MnO2 in a molar ratio of 1:(1~3), for example, 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:2.2, 1:2.4, 1:2.6, 1:2.8 or 1:3, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0016] Preferably, in the raw materials for preparing the high-voltage ceramic capacitor dielectric material, the mass ratio of Ca-B-Si microcrystalline glass powder to the total mass of the main component, the first auxiliary component, and the second auxiliary component is (0.5~1.5):100. For example, it can be 0.5:100, 0.6:100, 0.7:100, 0.8:100, 0.9:100, 1.0:100, 1.1:100, 1.2:100, 1.3:100, 1.4:100, or 1.5:100, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0017] Preferably, in the raw materials for preparing the high-voltage ceramic capacitor dielectric material, the total mass of the main component, the first auxiliary component, and the second auxiliary component is taken as 100%, the mass fraction of the main component is 85wt%~92wt%, the mass fraction of the first auxiliary component is 6.5wt%~14.5wt%, and the balance is the second auxiliary component.

[0018] In this invention, the total mass of the main component, the first auxiliary component, and the second auxiliary component is taken as 100%. The mass fraction of the main component is 85wt% to 92wt%, for example, it can be 85wt%, 86wt%, 87wt%, 88wt%, 89wt%, 90wt%, 91wt%, or 92wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0019] In this invention, the total mass of the main component, the first auxiliary component, and the second auxiliary component is taken as 100%. The mass fraction of the first auxiliary component is 6.5wt% to 14.5wt%, for example, it can be 6.5wt%, 7.5wt%, 8.5wt%, 9.5wt%, 10.5wt%, 11.5wt%, 12.5wt%, 13.5wt%, or 14.5wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] Preferably, the D50 particle size of the Ca-B-Si microcrystalline glass powder is 1μm to 2μm, for example, it can be 1.0μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm or 2.0μm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0021] In a second aspect, the present invention provides a method for preparing the high-voltage ceramic capacitor dielectric material described in the first aspect, the method comprising: Ca-B-Si microcrystalline glass powder is added during the preparation of high-voltage ceramic capacitor dielectric material to obtain high-voltage ceramic capacitor dielectric material.

[0022] Preferably, the method for preparing the Ca-B-Si microcrystalline glass powder includes: After mixing CaCO3, B2O3 and SiO2, the mixture is melted, quenched into glass sheets, and then pulverized to obtain Ca-B-Si microcrystalline glass powder.

[0023] Preferably, the melting temperature is 1500℃~1600℃ and the melting time is 2h~4h.

[0024] In this invention, the melting temperature is 1500℃~1600℃, for example, it can be 1500℃, 1510℃, 1520℃, 1530℃, 1540℃, 1550℃, 1560℃, 1570℃, 1580℃, 1590℃ or 1600℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0025] In this invention, the melting time is 2h to 4h, for example, it can be 2h, 2.2h, 2.4h, 2.6h, 2.8h, 3h, 3.2h, 3.4h, 3.6h, 3.8h or 4h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] Preferably, the quenching is performed on a roller mill with a gap of 0.5mm to 1mm, for example, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm or 1mm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0027] Preferably, the pulverizing method includes ball milling.

[0028] Preferably, the method for preparing the Ca-B-Si microcrystalline glass powder further includes drying and sieving sequentially after pulverization.

[0029] Preferably, the preparation method includes: The main component, the first auxiliary component, the second auxiliary component and Ca-B-Si microcrystalline glass powder are mixed and ball-milled to obtain powder. The obtained powder is then pressed and shaped, and then debinded and sintered in sequence to obtain high-voltage ceramic capacitor dielectric material.

[0030] Preferably, the method for preparing the main component includes: mixing barium titanate and strontium titanate; or mixing barium titanate and strontium titanate and then pre-calcining to obtain the main component.

[0031] Preferably, the method for preparing the first auxiliary component includes: mixing Bi2O3 and TiO2, and pre-calcining at 750℃~860℃ for 0.5h~1.5h to obtain the first auxiliary component.

[0032] In this invention, when preparing the first auxiliary component, the pre-calcination temperature is 750℃~860℃, for example, it can be 750℃, 760℃, 770℃, 780℃, 790℃, 800℃, 810℃, 820℃, 830℃, 840℃, 850℃ or 860℃, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0033] In this invention, when preparing the first auxiliary component, the pre-calcination time is 0.5h to 1.5h, for example, it can be 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1.0h, 1.1h, 1.2h, 1.3h, 1.4h or 1.5h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] Preferably, the method for preparing the second auxiliary component includes: mixing Nd2O3 and MnO2 to obtain the second auxiliary component.

[0035] Preferably, the ball milling includes wet ball milling, and the ball milling time is 2h to 6h, for example, it can be 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h or 6h, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0036] Preferably, the pressing pressure is 200 MPa to 500 MPa, for example, it can be 200 MPa, 220 MPa, 240 MPa, 260 MPa, 280 MPa, 300 MPa, 320 MPa, 340 MPa, 360 MPa, 380 MPa, 400 MPa, 420 MPa, 440 MPa, 460 MPa, 480 MPa or 500 MPa, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0037] Preferably, the pressing process yields a circular sheet with a diameter of 5mm to 15mm and a thickness of 0.1mm to 5mm.

[0038] In this invention, the pressed and formed material yields a circular piece with a diameter of 5mm to 15mm. For example, it can be 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm or 15mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0039] In this invention, the pressed and formed material yields a circular sheet with a thickness of 0.1mm to 5mm. For example, it can be 0.1mm, 0.3mm, 0.5mm, 0.8mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm, or 5.0mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] Preferably, the glue removal method includes a first heat treatment, wherein the temperature of the first heat treatment is 400℃~600℃ and the time is 2h~5h.

[0041] In this invention, the temperature of the first heat treatment is 400℃~600℃, for example, it can be 400℃, 420℃, 440℃, 460℃, 480℃, 500℃, 520℃, 540℃, 560℃, 580℃ or 600℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0042] In this invention, the first heat treatment time is 2h to 5h, for example, it can be 2h, 2.2h, 2.4h, 2.6h, 2.8h, 3h, 3.2h, 3.4h, 3.6h, 3.8h, 4h, 4.2h, 4.4h, 4.6h, 4.8h or 5h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0043] Preferably, the sintering temperature is 1150℃~1250℃ and the time is 1h~3h.

[0044] In this invention, the sintering temperature is 1150℃~1250℃, for example, it can be 1150℃, 1160℃, 1170℃, 1180℃, 1190℃, 1200℃, 1210℃, 1220℃, 1230℃, 1240℃ or 1250℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0045] In this invention, the sintering time is 1h to 3h, for example, it can be 1h, 1.2h, 1.4h, 1.6h, 1.8h, 2h, 2.2h, 2.4h, 2.6h, 2.8h or 3h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] Thirdly, the present invention provides a high-voltage ceramic capacitor dielectric material with electrodes.

[0047] Preferably, the preparation process of the dielectric material of the high-voltage ceramic capacitor with electrodes includes: The high-voltage ceramic capacitor dielectric material described in the first aspect is subjected to end-face silver paste printing and a second heat treatment to obtain a high-voltage ceramic capacitor dielectric material with electrodes.

[0048] Preferably, the temperature of the second heat treatment is 700℃~1000℃, and the time is 10min~20min.

[0049] In this invention, the temperature of the second heat treatment is 700℃~1000℃, for example, it can be 700℃, 730℃, 760℃, 790℃, 820℃, 850℃, 880℃, 910℃, 940℃, 970℃ or 1000℃, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0050] In this invention, the second heat treatment time is 10 min to 20 min, for example, it can be 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min or 20 min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0051] Fourthly, the present invention provides a ceramic capacitor, the ceramic capacitor comprising the high-voltage ceramic capacitor dielectric material described in the first aspect.

[0052] 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.

[0053] Compared with the prior art, the present invention has the following beneficial effects: This invention introduces Ca-B-Si microcrystalline glass powder into the raw materials for preparing high-voltage ceramic capacitor dielectric materials. Utilizing the powder's properties during sintering—forming a liquid phase to fill grain boundaries and micropore defects in the main crystalline phase, and simultaneously precipitating a large number of uniformly distributed micrograins in situ—this significantly improves the ceramic density and breakdown field strength of the high-voltage ceramic capacitor dielectric material. Furthermore, it effectively reduces the sintering temperature while maintaining the original high dielectric constant and low dielectric loss characteristics. In addition, the high-voltage ceramic capacitor dielectric material provided by this invention is a lead-free system, meeting the requirements of green environmental protection. Attached Figure Description

[0054] Figure 1 This is a SEM image of the high-voltage ceramic capacitor dielectric material disc obtained by the preparation method provided in Example 1.

[0055] Figure 2 This is a SEM image of the high-voltage ceramic capacitor dielectric material disc obtained by the preparation method provided in Comparative Example 1. Detailed Implementation

[0056] 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.

[0057] The "range" disclosed in this invention can be defined in the form of 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 the specific range. This type of range definition can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be arbitrarily combined, meaning 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 specific parameters, it is understood that ranges of 60~110 and 80~120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this invention, 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" and "5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, when a parameter is described as an integer selected from "2~10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0058] In this invention, "a combination of at least two" refers to a quantity greater than or equal to two, unless otherwise specified. For example, "any combination of one or at least two" means one or more or more items. It can be understood that when referring to "a combination of at least two," it refers to any suitable combination of multiple items, that is, a combination of "at least two" items carried out in a manner that does not conflict with and enables the implementation of this invention.

[0059] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0060] 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.

[0061] Those skilled in the art will understand that the order in which the steps are written in the methods of the various embodiments does not imply a strict execution order. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), meaning that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0062] In this invention, open-ended technical features or solutions described using terms such as "comprising" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, A includes a1, a2, and a3. Unless otherwise specified, it may also include other members or exclude additional members. This can be considered as providing both technical features or solutions where "A is composed of a1, a2, and a3" or "A is selected from a1, a2, and a3," and technical features or solutions where "A includes not only a1, a2, and a3, but also other members."

[0063] In this invention, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These 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" represents a group consisting of A, B, and "a combination of A and B". "Containing A and / or B" can mean "containing A, containing B, and containing A and B", or "containing A, containing B, or containing A and B", and can be appropriately understood according to the context.

[0064] In this invention, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on the quantity.

[0065] Example 1 This embodiment provides a high-voltage ceramic capacitor dielectric material disc, wherein the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc include Ca-B-Si microcrystalline glass powder with a D50 particle size of 1.5μm, and the raw materials for preparing the Ca-B-Si microcrystalline glass powder include CaCO3, B2O3 and SiO2. Based on the mass percentage of the raw materials used in the preparation of the Ca-B-Si microcrystalline glass powder, the raw materials for preparing the Ca-B-Si microcrystalline glass powder contain 35 wt% CaCO3, 26 wt% B2O3, and 39 wt% SiO2. The raw materials for preparing the high-voltage ceramic capacitor dielectric material disc also include a main component, which includes barium titanate and strontium titanate with a molar ratio of Ba to Sr of 72:28. The raw materials for preparing the high-voltage ceramic capacitor dielectric material disc also include a first auxiliary component, which includes Bi2O3 and TiO2 in a molar ratio of 1:2. The raw materials for preparing the high-voltage ceramic capacitor dielectric material disc also include a second auxiliary component, which includes Nd2O3 and MnO2 in a molar ratio of 1:2.

[0066] In the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc, the mass ratio of Ca-B-Si microcrystalline glass powder to the total mass of the main component, the first auxiliary component, and the second auxiliary component is 1.0:100. In the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc, the total mass of the main component, the first auxiliary component, and the second auxiliary component is taken as 100%, the mass fraction of the main component is 88wt%, the mass fraction of the first auxiliary component is 11wt%, and the remainder is the second auxiliary component.

[0067] The method for preparing the high-voltage ceramic capacitor dielectric material wafer is as follows: (1) Preparation of the main component: Barium titanate and strontium titanate were mixed to obtain the main component; Preparation of the first auxiliary component: Bi2O3 and TiO2 were mixed and pre-calcined at 810℃ for 1 hour to obtain the first auxiliary component; Preparation of the second auxiliary component: Nd2O3 and MnO2 were mixed to obtain the second auxiliary component; Preparation of Ca-B-Si microcrystalline glass powder: After mixing CaCO3, B2O3 and SiO2, the mixture is melted at 1550℃ for 3 hours, then quenched on a roller mill with a gap of 0.8 mm to obtain glass sheets, followed by wet ball milling, drying and sieving to obtain Ca-B-Si microcrystalline glass powder. (2) After mixing the main component, the first auxiliary component and the second auxiliary component obtained in step (1) by wet ball milling for 4 hours, the mixture is dried and sieved in sequence to obtain the base powder; The obtained base powder is then mixed with the Ca-B-Si microcrystalline glass powder obtained in step (1) and then wet ball milled for 4 hours to obtain powder. The obtained powder is then pressed into shape under a pressure of 300 MPa to obtain a disc with a diameter of 10 mm and a thickness of 1 mm. The obtained wafer was then heated to 500℃ at a rate of 5℃ / min, and held at that temperature for 3 hours to remove the adhesive. It was then heated to 1200℃ at a rate of 5℃ / min and sintered for 2 hours to obtain a high-voltage ceramic capacitor dielectric material wafer. The obtained high-voltage ceramic capacitor dielectric material wafer was tested using a scanning electron microscope, and the SEM image of the high-voltage ceramic capacitor dielectric material wafer obtained by the preparation method provided in this embodiment is shown below. Figure 1 As shown.

[0068] This embodiment provides a high-voltage ceramic capacitor dielectric material wafer with electrodes. The fabrication process of the high-voltage ceramic capacitor dielectric material wafer with electrodes includes: After printing silver paste on the end face of the high-voltage ceramic capacitor dielectric material disc provided in this embodiment, it is heat-treated at 800°C for 15 minutes to obtain a high-voltage ceramic capacitor dielectric material disc with electrodes.

[0069] Example 2 This embodiment provides a high-voltage ceramic capacitor dielectric material disc, wherein the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc include Ca-B-Si microcrystalline glass powder with a D50 particle size of 1μm, and the raw materials for preparing the Ca-B-Si microcrystalline glass powder include CaCO3, B2O3 and SiO2. Based on the mass percentage of the raw materials used in the preparation of the Ca-B-Si microcrystalline glass powder, the raw materials for preparing the Ca-B-Si microcrystalline glass powder contain 40 wt% CaCO3, 30 wt% B2O3, and 30 wt% SiO2. The raw materials for preparing the high-voltage ceramic capacitor dielectric material wafer also include a main component, which includes barium titanate and strontium titanate with a molar ratio of Ba to Sr of 65:35. The raw materials for preparing the high-voltage ceramic capacitor dielectric material disc also include a first auxiliary component, which includes Bi2O3 and TiO2 in a molar ratio of 1:3. The raw materials for preparing the high-voltage ceramic capacitor dielectric material disc also include a second auxiliary component, which includes Nd2O3 and MnO2 in a molar ratio of 1:1. In the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc, the mass ratio of Ca-B-Si microcrystalline glass powder to the total mass of the main component, the first auxiliary component, and the second auxiliary component is 1.5:100. In the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc, the total mass of the main component, the first auxiliary component, and the second auxiliary component is taken as 100%, the mass fraction of the main component is 92wt%, the mass fraction of the first auxiliary component is 6.5wt%, and the balance is the second auxiliary component.

[0070] The method for preparing the high-voltage ceramic capacitor dielectric material wafer is as follows: (1) Preparation of the main component: Barium titanate and strontium titanate were mixed to obtain the main component; Preparation of the first auxiliary component: Bi2O3 and TiO2 were mixed and pre-calcined at 810℃ for 1 hour to obtain the first auxiliary component; Preparation of the second auxiliary component: Nd2O3 and MnO2 were mixed to obtain the second auxiliary component; Preparation of Ca-B-Si microcrystalline glass powder: After mixing CaCO3, B2O3 and SiO2, the mixture is melted at 1500℃ for 4 hours, then quenched on a roller mill with a gap of 0.5mm to obtain glass sheets, followed by wet ball milling, drying and sieving to obtain Ca-B-Si microcrystalline glass powder. (2) After mixing the main component, the first auxiliary component and the second auxiliary component obtained in step (1) by wet ball milling for 4 hours, the mixture is dried and sieved in sequence to obtain the base powder; The obtained base powder is then mixed with the Ca-B-Si microcrystalline glass powder obtained in step (1) and then wet ball milled for 6 hours to obtain powder. The obtained powder is then pressed into shape under a pressure of 500 MPa to obtain a disc with a diameter of 10 mm and a thickness of 1.0 mm. The obtained disc is then heated to 400℃ at a rate of 5℃ / min, and then held at that temperature for 5 hours to remove the adhesive. Finally, it is heated to 1250℃ at a rate of 5℃ / min and sintered for 1 hour to obtain a disc of high-voltage ceramic capacitor dielectric material.

[0071] This embodiment provides a high-voltage ceramic capacitor dielectric material wafer with electrodes. The fabrication process of the high-voltage ceramic capacitor dielectric material wafer with electrodes includes: After printing silver paste on the end face of the high-voltage ceramic capacitor dielectric material disc provided in this embodiment, it is heat-treated at 700°C for 20 minutes to obtain a high-voltage ceramic capacitor dielectric material disc with electrodes.

[0072] Example 3 This embodiment provides a high-voltage ceramic capacitor dielectric material disc, wherein the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc include Ca-B-Si microcrystalline glass powder with a D50 particle size of 2μm, and the raw materials for preparing the Ca-B-Si microcrystalline glass powder include CaCO3, B2O3 and SiO2. Based on the mass percentage of the raw materials used in the preparation of the Ca-B-Si microcrystalline glass powder, the raw materials for preparing the Ca-B-Si microcrystalline glass powder contain 30 wt% CaCO3, 22 wt% B2O3, and 48 wt% SiO2. The raw materials for preparing the high-voltage ceramic capacitor dielectric material disc also include a main component, which includes barium titanate and strontium titanate with a molar ratio of Ba to Sr of 79:21. The raw materials for preparing the high-voltage ceramic capacitor dielectric material disc also include a first auxiliary component, which includes Bi2O3 and TiO2 in a molar ratio of 1:1. The raw materials for preparing the high-voltage ceramic capacitor dielectric material disc also include a second auxiliary component, which includes Nd2O3 and MnO2 in a molar ratio of 1:3. In the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc, the mass ratio of Ca-B-Si microcrystalline glass powder to the total mass of the main component, the first auxiliary component, and the second auxiliary component is 0.5:100. In the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc, the total mass of the main component, the first auxiliary component, and the second auxiliary component is taken as 100%, the mass fraction of the main component is 85wt%, the mass fraction of the first auxiliary component is 14.5wt%, and the balance is the second auxiliary component.

[0073] The method for preparing the high-voltage ceramic capacitor dielectric material wafer is as follows: (1) Preparation of the main component: Barium titanate and strontium titanate were mixed to obtain the main component; Preparation of the first auxiliary component: Bi2O3 and TiO2 were mixed and pre-calcined at 810℃ for 1 hour to obtain the first auxiliary component; Preparation of the second auxiliary component: Nd2O3 and MnO2 were mixed to obtain the second auxiliary component; Preparation of Ca-B-Si microcrystalline glass powder: After mixing CaCO3, B2O3 and SiO2, the mixture is melted at 1600℃ for 2 hours, then quenched on a roller mill with a gap of 1 mm to obtain glass sheets, followed by wet ball milling, drying and sieving to obtain Ca-B-Si microcrystalline glass powder. (2) After mixing the main component, the first auxiliary component and the second auxiliary component obtained in step (1) by wet ball milling for 4 hours, the mixture is dried and sieved in sequence to obtain the base powder; The obtained base powder is then mixed with the Ca-B-Si microcrystalline glass powder obtained in step (1) and then wet ball milled for 2h~6h to obtain powder. The obtained powder is then pressed into shape under a pressure of 200Mpa~500Mpa to obtain a disc with a diameter of 10mm and a thickness of 1.0mm. The obtained disc is then heated to 600℃ at a rate of 5℃ / min, and then held at that temperature for 2 hours to remove the adhesive. After that, it is heated to 1150℃ at a rate of 5℃ / min and sintered for 3 hours to obtain a disc of high voltage ceramic capacitor dielectric material.

[0074] This embodiment provides a high-voltage ceramic capacitor dielectric material wafer with electrodes. The fabrication process of the high-voltage ceramic capacitor dielectric material wafer with electrodes includes: After printing silver paste on the end face of the high-voltage ceramic capacitor dielectric material disc provided in this embodiment, it is heat-treated at 1000℃ for 10 minutes to obtain a high-voltage ceramic capacitor dielectric material disc with electrodes.

[0075] Example 4 This embodiment provides a high-voltage ceramic capacitor dielectric material disc. Except that the mass of the raw materials for preparing the Ca-B-Si microcrystalline glass powder is taken as 100%, the mass fraction of CaCO3 in the raw materials for preparing the Ca-B-Si microcrystalline glass powder is 20wt%, and the mass fraction of B2O3 and SiO2 is increased proportionally, the rest are the same as in Example 1.

[0076] This embodiment provides a high-voltage ceramic capacitor dielectric material disc with electrodes. Except for replacing the high-voltage ceramic capacitor dielectric material disc in the preparation process with the high-voltage ceramic capacitor dielectric material disc provided in this embodiment, everything else is the same as in Embodiment 1.

[0077] Example 5 This embodiment provides a high-voltage ceramic capacitor dielectric material disc. Except that the mass of the raw materials for preparing the Ca-B-Si microcrystalline glass powder is taken as 100%, the mass fraction of CaCO3 in the raw materials for preparing the Ca-B-Si microcrystalline glass powder is 50wt%, and the mass fractions of B2O3 and SiO2 are reduced accordingly, the rest are the same as in Example 1.

[0078] This embodiment provides a high-voltage ceramic capacitor dielectric material disc with electrodes. Except for replacing the high-voltage ceramic capacitor dielectric material disc in the preparation process with the high-voltage ceramic capacitor dielectric material disc provided in this embodiment, everything else is the same as in Embodiment 1.

[0079] Example 6 This embodiment provides a high-voltage ceramic capacitor dielectric material disc. Except that the mass ratio of Ca-B-Si microcrystalline glass powder to the total mass of the main component, the first auxiliary component, and the second auxiliary component in the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc is 0.2:100, all other aspects are the same as in Embodiment 1.

[0080] This embodiment provides a high-voltage ceramic capacitor dielectric material disc with electrodes. Except for replacing the high-voltage ceramic capacitor dielectric material disc in the preparation process with the high-voltage ceramic capacitor dielectric material disc provided in this embodiment, everything else is the same as in Embodiment 1.

[0081] Example 7 This embodiment provides a high-voltage ceramic capacitor dielectric material disc. Except that the mass ratio of Ca-B-Si microcrystalline glass powder to the total mass of the main component, the first auxiliary component, and the second auxiliary component in the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc is 2.0:100, all other aspects are the same as in Embodiment 1.

[0082] This embodiment provides a high-voltage ceramic capacitor dielectric material disc with electrodes. Except for replacing the high-voltage ceramic capacitor dielectric material disc in the preparation process with the high-voltage ceramic capacitor dielectric material disc provided in this embodiment, everything else is the same as in Embodiment 1.

[0083] Example 8 This embodiment provides a high-voltage ceramic capacitor dielectric material disc. Except for the Ca-B-Si microcrystalline glass powder with a D50 particle size of 0.5 μm in the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc, all other aspects are the same as in Example 1.

[0084] This embodiment provides a high-voltage ceramic capacitor dielectric material disc with electrodes. Except for replacing the high-voltage ceramic capacitor dielectric material disc in the preparation process with the high-voltage ceramic capacitor dielectric material disc provided in this embodiment, everything else is the same as in Embodiment 1.

[0085] Example 9 This embodiment provides a high-voltage ceramic capacitor dielectric material disc. Except for the Ca-B-Si microcrystalline glass powder with a D50 particle size of 2.0 μm in the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc, all other aspects are the same as in Example 1.

[0086] This embodiment provides a high-voltage ceramic capacitor dielectric material disc with electrodes. Except for replacing the high-voltage ceramic capacitor dielectric material disc in the preparation process with the high-voltage ceramic capacitor dielectric material disc provided in this embodiment, everything else is the same as in Embodiment 1.

[0087] Example 10 This embodiment provides a high-voltage ceramic capacitor dielectric material disc. Except for step (2) of the preparation method of the high-voltage ceramic capacitor dielectric material disc, which involves heating to 1050°C after debinding and then sintering, the rest is the same as in Example 1.

[0088] This embodiment provides a high-voltage ceramic capacitor dielectric material disc with electrodes. Except for replacing the high-voltage ceramic capacitor dielectric material disc in the preparation process with the high-voltage ceramic capacitor dielectric material disc provided in this embodiment, everything else is the same as in Embodiment 1.

[0089] Example 11 This embodiment provides a high-voltage ceramic capacitor dielectric material disc. Except for step (2) of the preparation method of the high-voltage ceramic capacitor dielectric material disc, which involves heating to 1300°C after debinding and then sintering, the rest is the same as in Example 1.

[0090] This embodiment provides a high-voltage ceramic capacitor dielectric material disc with electrodes. Except for replacing the high-voltage ceramic capacitor dielectric material disc in the preparation process with the high-voltage ceramic capacitor dielectric material disc provided in this embodiment, everything else is the same as in Embodiment 1.

[0091] Comparative Example 1 This comparative example provides a high-voltage ceramic capacitor dielectric material disc, except that the Ca-B-Si microcrystalline glass powder in the raw materials for preparing the high-voltage ceramic capacitor dielectric material disc is omitted, that is, the step (2) of the preparation method of the high-voltage ceramic capacitor dielectric material disc, "the obtained base powder is mixed with the Ca-B-Si microcrystalline glass powder obtained in step (1) and then wet ball milled for 4 hours to obtain powder", is omitted, and the obtained base powder is directly pressed into shape. The rest is the same as in Example 1. Among them, the high-voltage ceramic capacitor dielectric material disc obtained by the preparation method provided in this comparative example is tested by scanning electron microscopy, and the SEM image of the high-voltage ceramic capacitor dielectric material disc obtained by the preparation method provided in this comparative example is as follows. Figure 2 As shown.

[0092] This comparative example provides a high-voltage ceramic capacitor dielectric material disc with electrodes. Except for replacing the high-voltage ceramic capacitor dielectric material disc in the preparation process with the high-voltage ceramic capacitor dielectric material disc provided in this comparative example, everything else is the same as in Example 1.

[0093] The ceramic wafer density of the high-voltage ceramic capacitor dielectric material discs provided in the above embodiments and comparative examples was tested. The test method was in accordance with GB / T 25995-2010, using Archimedes' water displacement method. The ceramic wafer density obtained is shown in Table 1.

[0094] The high-voltage ceramic capacitor dielectric material discs with electrodes provided in the above embodiments and comparative examples were sequentially welded and encapsulated to prepare intercalation capacitors. Electrical performance tests were then conducted, with specific testing standards referring to GB / T 6346.1-2024 / IEC 60384-1:2021. The dielectric loss obtained from the tests and the calculated breakdown field strength and dielectric constant are shown in Table 1.

[0095] Table 1

[0096] From Table 1, we can obtain: (1) The high voltage ceramic capacitor dielectric material wafers provided in Examples 1-3 exhibit high ceramic density, high breakdown field strength, high dielectric constant and low dielectric loss, and are lead-free dielectric materials.

[0097] (2) By comparing Example 1 with Examples 4 and 5, it can be seen that in this invention, taking the mass of the raw materials for preparing Ca-B-Si microcrystalline glass powder as 100%, when the mass fraction of CaCO3 in the raw materials for preparing Ca-B-Si microcrystalline glass powder is 30wt%~40wt%, the high voltage ceramic capacitor dielectric material disc exhibits better comprehensive performance. This is because when the mass fraction of CaCO3 is 30wt%~40wt%, the liquid phase generation amount and crystallization ability of Ca-B-Si microcrystalline glass powder are best matched, which can not only fully fill defects, but also precipitate an appropriate amount of high dielectric fine grains, avoiding excessive low dielectric crystal phase generation.

[0098] (3) By comparing Example 1 with Examples 6 and 7, it can be seen that in the present invention, when the mass ratio of Ca-B-Si microcrystalline glass powder to the total mass of the main component, the first auxiliary component and the second auxiliary component in the raw materials for preparing the high voltage ceramic capacitor dielectric material disc is (0.5~1.5):100, the high voltage ceramic capacitor dielectric material disc exhibits better comprehensive performance. This is because when the amount of Ca-B-Si microcrystalline glass powder added is too low, the liquid phase filling and crystallization enhancement effect is insufficient, and when the amount of Ca-B-Si microcrystalline glass powder added is too high, the proportion of glass phase is too large, which will significantly reduce the overall dielectric constant and breakdown field strength of the high voltage ceramic capacitor dielectric material disc.

[0099] (4) By comparing Example 1 with Examples 8 and 9, it can be seen that in the present invention, when the D50 particle size of the Ca-B-Si microcrystalline glass powder in the raw materials for preparing the high voltage ceramic capacitor dielectric material disc is 1μm~2μm, the high voltage ceramic capacitor dielectric material disc exhibits better comprehensive performance. This is because when the D50 particle size of the Ca-B-Si microcrystalline glass powder is in this range, the dispersion effect of the Ca-B-Si microcrystalline glass powder is the best, and the liquid phase can be uniformly distributed at the grain boundary, avoiding local defects caused by excessively large particle size or agglomeration problems caused by excessively small particle size.

[0100] (5) By comparing Example 1 with Examples 10 and 11, it can be seen that in the preparation method of the high voltage ceramic capacitor dielectric material disc in the present invention, when the sintering temperature after debinding is 1150℃~1250℃, the high voltage ceramic capacitor dielectric material disc exhibits better comprehensive performance. This is because when the sintering temperature is too low, it will lead to insufficient density and more micropores. When the sintering temperature is too high, it will lead to abnormal growth of the main crystal phase grains and thinning of the grain boundaries, resulting in a decrease in breakdown field strength and an increase in dielectric loss.

[0101] (6) As can be seen from the comparison between Example 1 and Comparative Example 1, the present invention introduces Ca-B-Si microcrystalline glass powder into the raw materials for preparing high-voltage ceramic capacitor dielectric material. By utilizing its characteristics of forming a liquid phase to fill the grain boundaries and micropore defects of the main crystal phase during sintering, and simultaneously precipitating a large number of uniformly distributed micro-grains in situ, the present invention significantly improves the ceramic density and breakdown field strength of the high-voltage ceramic capacitor dielectric material, effectively reduces the sintering temperature, and maintains the original high dielectric constant and low dielectric loss characteristics. In addition, the high-voltage ceramic capacitor dielectric material provided by the present invention is a lead-free system, which meets the requirements of green environmental protection.

[0102] 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 high-voltage ceramic capacitor dielectric material, characterized in that, The raw materials for preparing the high-voltage ceramic capacitor dielectric material include Ca-B-Si microcrystalline glass powder, and the raw materials for preparing the Ca-B-Si microcrystalline glass powder include CaCO3, B2O3 and SiO2.

2. The high-voltage ceramic capacitor dielectric material according to claim 1, characterized in that, Based on the mass percentage of the raw materials used in the preparation of the Ca-B-Si microcrystalline glass powder, the mass fraction of CaCO3 in the raw materials used in the preparation of the Ca-B-Si microcrystalline glass powder is 30wt%~40wt%; And / or, based on the mass of the raw materials used to prepare the Ca-B-Si microcrystalline glass powder, the mass fraction of B2O3 in the raw materials used to prepare the Ca-B-Si microcrystalline glass powder is 22wt%~30wt%; And / or, based on the mass of the raw materials for preparing the Ca-B-Si microcrystalline glass powder, the mass fraction of SiO2 in the raw materials for preparing the Ca-B-Si microcrystalline glass powder is 30wt%~48wt%.

3. The high-voltage ceramic capacitor dielectric material according to claim 1, characterized in that, The raw materials for preparing the high-voltage ceramic capacitor dielectric material also include a main component, which includes barium titanate and strontium titanate in a molar ratio of Ba to Sr of (65~79):(21~35). And / or, the raw materials for preparing the high voltage ceramic capacitor dielectric material further include a first auxiliary component, which includes Bi2O3 and TiO2 in a molar ratio of 1:(1~3); And / or, the raw materials for preparing the high-voltage ceramic capacitor dielectric material further include a second auxiliary component, which includes Nd2O3 and MnO2 in a molar ratio of 1:(1~3).

4. The high-voltage ceramic capacitor dielectric material according to any one of claims 1 to 3, characterized in that, In the raw materials for preparing the high-voltage ceramic capacitor dielectric material, the mass ratio of Ca-B-Si microcrystalline glass powder to the total mass of the main component, the first auxiliary component, and the second auxiliary component is (0.5~1.5):

100. And / or, in the raw materials for preparing the high-voltage ceramic capacitor dielectric material, the total mass of the main component, the first auxiliary component, and the second auxiliary component is taken as 100%, the mass fraction of the main component is 85wt%~92wt%, the mass fraction of the first auxiliary component is 6.5wt%~14.5wt%, and the balance is the second auxiliary component; And / or, the D50 particle size of the Ca-B-Si microcrystalline glass powder is 1μm~2μm.

5. A method for preparing the high-voltage ceramic capacitor dielectric material according to any one of claims 1 to 4, characterized in that, The preparation method includes: Ca-B-Si microcrystalline glass powder is added during the preparation of high-voltage ceramic capacitor dielectric material to obtain high-voltage ceramic capacitor dielectric material.

6. The preparation method according to claim 5, characterized in that, The method for preparing the Ca-B-Si microcrystalline glass powder includes: After mixing CaCO3, B2O3 and SiO2, the mixture is melted, quenched into glass sheets, and then pulverized to obtain Ca-B-Si microcrystalline glass powder.

7. The preparation method according to claim 6, characterized in that, The melting temperature is 1500℃~1600℃, and the melting time is 2h~4h; And / or, the quenching is performed on a roller mill with a gap of 0.5 mm to 1 mm.

8. The preparation method according to any one of claims 5 to 7, characterized in that, The preparation method includes: The main component, the first auxiliary component, the second auxiliary component and Ca-B-Si microcrystalline glass powder are mixed and ball-milled to obtain powder. The obtained powder is then pressed and shaped, and then debinded and sintered in sequence to obtain high-voltage ceramic capacitor dielectric material.

9. The preparation method according to claim 8, characterized in that, The method for removing adhesive includes a first heat treatment, wherein the temperature of the first heat treatment is 400℃~600℃ and the time is 2h~5h; And / or, the sintering temperature is 1150℃~1250℃, and the time is 1h~3h.

10. A ceramic capacitor, characterized in that, The ceramic capacitor includes the high-voltage ceramic capacitor dielectric material as described in any one of claims 1 to 4.

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