Microwave ceramic material as well as preparation method and application thereof

Abstract

The invention provides a microwave ceramic material as well as a preparation method and application thereof, and belongs to the technical field of ceramic materials. The microwave ceramic material provided by the invention comprises the following components in percentage by mass: 5.50%-92.00% of a main material BaZn2Ti4O11850; an auxiliary material Ba (SmxNd1-x) 2.3% Ti 4.5% O is 13.450.74-7.95%, and x is greater than or equal to 0.50 and less than or equal to 0.70; an auxiliary material CaySm < 2 > / 3 (1-y) TiO < 3 > is 3.00-6.13%, wherein y is greater than or equal to 0.50 and less than or equal to 0.80; 0.07%-0.27% of a sintering aid; 0.03% to 0.05% of MnO2; and 0.52%-2.03% of Dy2O3. The microwave ceramic material provided by the invention has excellent comprehensive performance under the condition of relatively low sintering temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of ceramic materials, and in particular to a microwave ceramic material and a preparation method and application thereof. Background Art

[0002] Microwave communication technology has developed rapidly with the advent of the 5G and sub-6G technology era. Most microwave-based equipment systems use a frequency range of 300MHz to 300GHz. Microwave communication occupies an important position in wireless communication technology. It has the advantages of large transmission capacity, high transmission quality, and long transmission distance. The millimeter wave frequency band provides rich resources for the utilization and development of new spectrum of 5G communication technology. The combination of microwave technology and 5G network enables the Internet of Things to achieve the interconnection of all things. At the same time, microwave components are gradually developing towards high frequency, small integration, high-efficiency and high-quality transmission, large amount of information, and temperature stability. For example, chip-type multilayer ceramic capacitors (MLCC) are widely used in coupling, oscillation, filtering and bypass circuits of various electronic equipment such as microwave communications, power amplifiers, and transmitters because of their small size, chip-type, and high reliability. They are especially widely used in high-frequency circuits. As the key material for making ceramic capacitors, microwave ceramic materials have higher and higher requirements for their performance.

[0003] For microwave ceramic materials, a higher dielectric constant (ε r >20) helps to miniaturize the device; lower dielectric loss (tanδ<5×10 -4 ) is conducive to improving the selectivity of the device's operating frequency and reducing the device's energy conversion consumption; lower insulation resistance will increase the leakage current of electronic components during operation, accelerate the aging of capacitors, and cause reliability problems such as failure, cracking, and equipment failure; smaller temperature coefficients and capacitance ranges will make the resulting ceramic capacitors work more stably under different temperature environments. For example, the current C0G microwave ceramic material requires that the capacitance temperature coefficient (TCC) in the temperature range of -55℃ to +125℃ be in the range of -30 to +30ppm / ℃, and the capacitance temperature coefficient range can reach 60ppm / ℃, while a larger range will affect signal transmission, resulting in unstable working conditions of the entire electronic machine.

[0004] BaZn2Ti4O 11 The ceramic material is an orthorhombic phase with a space group of Pbcn. After sintering at 1200°C, excellent dielectric properties can be obtained: ε r =30, Q×f=68000GHz, τ f=-30ppm / ℃, and the capacitance temperature coefficient in the temperature range of -55℃~+125℃ is +55~+70ppm / ℃. This ceramic material is an intermediate microwave ceramic material, but its large temperature coefficient and high sintering temperature limit its application in microwave components such as MLCC. Summary of the invention

[0005] The purpose of the present invention is to provide a microwave ceramic material and a preparation method and application thereof. The microwave ceramic material provided by the present invention has a medium dielectric constant, low dielectric loss, a small and stable capacitance temperature coefficient and a high insulation resistivity under low sintering temperature conditions, and has excellent comprehensive performance.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a microwave ceramic material, which comprises the following components by weight percentage:

[0008] Main material: BaZn2Ti4O 11 85.50%~92.00%%;

[0009] Auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 0.74%~7.95%, 0.50≤x≤0.70;

[0010] Auxiliary material Ca y Sm 2 / 3(1-y) TiO33.00%~6.13%, 0.50≤y≤0.80;

[0011] Sintering aid 0.07%~0.27%;

[0012] MnO2 0.03%~0.05%;

[0013] Dy2O30.52%~2.03%.

[0014] Preferably, the main material BaZn2Ti4O 11 The preparation method comprises the following steps:

[0015] According to the main material BaZn2Ti4O 11 BaCO3, ZnO and TiO2 are mixed in a stoichiometric ratio and calcined for the first time to obtain the main material BaZn2Ti4O 11 .

[0016] Preferably, the temperature of the first calcination is 1050-1100° C., and the holding time is 2-4 hours.

[0017] Preferably, the auxiliary material Ba (Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 The preparation method comprises the following steps:

[0018] According to the auxiliary material Ba (Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 BaCO3, Sm2O3, Nd2O3 and TiO2 are mixed in a stoichiometric ratio and subjected to a second calcination to obtain the auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 .

[0019] Preferably, the temperature of the second calcination is 1090-1150° C., and the holding time is 2-4 hours.

[0020] Preferably, the auxiliary material Ca y Sm 2 / 3(1-y) The preparation method of TiO3 comprises the following steps:

[0021] According to the auxiliary material Ca y Sm 2 / 3(1-y) TiO3 stoichiometric ratio CaCO3, Sm2O3 and TiO2 are mixed and calcined for the third time to obtain the auxiliary material Ca y Sm 2 / 3(1-y) TiO3.

[0022] Preferably, the temperature of the third calcination is 1100-1200° C., and the holding time is 2-4 hours.

[0023] The present invention provides a method for preparing the microwave ceramic material described in the above technical solution, comprising the following steps:

[0024] The main material BaZn2Ti4O 11 、Auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 、Auxiliary material Ca y Sm 2 / 3(1-y) TiO3, sintering aid, MnO2 and Dy2O3 are mixed to obtain the microwave ceramic material.

[0025] The present invention provides application of the microwave ceramic material described in the above technical solution or the microwave ceramic material prepared by the preparation method described in the above technical solution in microwave components.

[0026] Preferably, the microwave components include capacitors, microwave substrates, resonators, filters or dielectric antennas.

[0027] The present invention provides a microwave ceramic material, which comprises the following components by weight percentage: a main material BaZn2Ti4O 11 85.50%~92.00%; auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 0.74%~7.95%, 0.50≤x≤0.70; auxiliary material Ca y Sm 2 / 3(1-y) TiO3 3.00% to 6.13%, 0.50 ≤ y ≤ 0.80; sintering aid 0.07% to 0.27%; MnO2 0.03% to 0.05%; Dy2O3 0.52% to 2.03%. 11 As the base material, add auxiliary material Ba (Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 (0.50≤x≤0.70), auxiliary material Ca y Sm 2 / 3(1-y) TiO3 (0.50≤y≤0.80) and modified additives MnO2 and Dy2O3 are used to adjust the comprehensive electrical properties of microwave ceramic materials. At the same time, the addition of sintering aids is beneficial to reduce the sintering temperature, so that the microwave ceramic material has excellent comprehensive properties under the condition of lower sintering temperature (1080~1120℃): medium dielectric constant (26.3~32.1); lower dielectric loss (tanδ<2×10 -4 , the lowest can be as low as 0.4×10 -4 ); It has a relatively stable capacity temperature coefficient in the temperature range of -55 to +125°C, and the capacity temperature coefficient is adjustable, and the best can be close to zero (-1.5 to -0.6ppm / °C); The room temperature and high temperature insulation resistivity are high, both can reach 1×10 14Ω·cm or more, especially the high temperature insulation resistivity is higher than the insulation resistivity of C0G ceramic materials in the prior art (such as BaCO3-based ceramics in patent application CN 117229052A, SrZrO3-based ceramics in CN 116947486A, and CaZrO3-based ceramics in CN 118344132A). Therefore, the microwave ceramic material provided by the present invention can be used for the manufacture of microwave components such as capacitors, microwave substrates, resonators, filters, dielectric antennas, etc., such as meeting the requirements of co-firing matching process of ceramic dielectric and inner electrode materials, stable capacitance temperature coefficient and high reliability in MLCC applications.

[0028] In addition, the preparation process of the microwave ceramic material of the present invention is simple, batch production can be easily realized, the raw material cost is low, and it is green and environmentally friendly, and is suitable for popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the SEM image of the microwave ceramic material in Example 9 (formulation number 11) after sintering at 1100°C for 3 hours. DETAILED DESCRIPTION

[0030] The present invention provides a microwave ceramic material, which comprises the following components by weight percentage:

[0031] Main material: BaZn2Ti4O 11 85.50%~92.00%;

[0032] Auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 0.74%~7.95%, 0.50≤x≤0.70;

[0033] Auxiliary material Ca y Sm 2 / 3(1-y) TiO33.00%~6.13%, 0.50≤y≤0.80;

[0034] Sintering aid 0.07%~0.27%;

[0035] MnO2 0.03%~0.05%;

[0036] Dy2O30.52%~2.03%.

[0037] Calculated by mass percentage, the components of the microwave ceramic material of the present invention include the main material BaZn2Ti4O 1185.50% to 92.00%, for example, it can be 85.50%, 86.00%, 86.50%, 87.08%, 87.41%, 87.60%, 87.85%, 88.20%, 88.23%, 88.60%, 89.00%, 89.50%, 90.28%, 90.50%, 91.00%, 91.50% or 92.00%.

[0038] In the present invention, the main material BaZn2Ti4O 11 The preparation method preferably comprises the following steps: 11 BaCO3, ZnO and TiO2 are mixed in a stoichiometric ratio and calcined for the first time to obtain the main material BaZn2Ti4O 11 . In the present invention, the purity of the BaCO3, ZnO and TiO2 is preferably above 99wt%. In the present invention, the mixing method of the BaCO3, ZnO and TiO2 is preferably ball milling, and the ball milling is preferably carried out in the presence of water and ball milling medium. The water is preferably deionized water, and the ball milling medium is preferably zirconia balls; the rotation speed of the ball milling is preferably 150-400rpm, more preferably 300rpm; the time is preferably 3-10h, more preferably 3.5-4.5h. In the present invention, after the ball milling, it is preferred to further include drying and sieving in sequence; the drying temperature is preferably 110-125℃, more preferably 115-120℃; the time is preferably 6-8h, more preferably 6.5-7h; the mesh number of the sieve used for the sieving is preferably 40-60 mesh, more preferably 50-60 mesh; after the sieving, the material under the sieve is collected for the first calcination. In the present invention, the temperature of the first calcination is preferably 1050-1100° C., more preferably 1070-1080° C.; the holding time is preferably 2-4 hours, more preferably 2.5-3 hours.

[0039] Calculated by mass percentage, the components of the microwave ceramic material of the present invention include auxiliary materials Ba (Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.450.74% to 7.95%, for example, it can be 0.74%, 1.00%, 1.30%, 1.50%, 2.00%, 2.5%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.30%, 5.8%, 6.00%, 6.10%, 6.13%, 6.15%, 6.18%, 6.20%, 6.25%, 6.50%, 7.00%, 7.24%, 7.50%, 7.75% or 7.95%; 0.5≤x≤0.7, and the x can be, for example, 0.50, 0.55, 0.60, 0.65 or 0.70.

[0040] In the present invention, the auxiliary material Ba (Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 The preparation method preferably comprises the following steps: x Nd 1-x ) 2.3 Ti 4.5 O 13.45 BaCO3, Sm2O3, Nd2O3 and TiO2 are mixed in a stoichiometric ratio and subjected to a second calcination to obtain the auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 In the present invention, the purity of BaCO3, Sm2O3, Nd2O3 and TiO2 is preferably above 99wt%. In the present invention, the mixing method of BaCO3, Sm2O3, Nd2O3 and TiO2 is preferably ball milling. The specific optional conditions of ball milling are preferably the same as those for preparing the main material BaZn2Ti4O 11 The optional conditions for ball milling and mixing are the same and will not be described here. In the present invention, the ball milling and mixing preferably further include drying and sieving in sequence; the specific optional conditions for drying and sieving are preferably the same as those for preparing the main material BaZn2Ti4O 11 The optional conditions for drying and sieving are the same and will not be described in detail. In the present invention, the temperature of the second calcination is preferably 1090-1150°C, more preferably 1110-1130°C; the holding time is preferably 2-4h, more preferably 2.5-3h.

[0041] Calculated by mass percentage, the components of the microwave ceramic material of the present invention include auxiliary material Ca y Sm 2 / 3(1-y)TiO33.00%~6.13%, for example, it can be 3.00%, 3.08%, 3.30%, 3.50%, 3.70%, 3.95%, 4.00%, 4.20%, 4.25%, 4.50%, 4.70%, 4.95%, 5.20%, 5.50%, 5.70%, 6.00% or 6.13%; 0.50≤y≤0.80, and y can be, for example, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75 or 0.80.

[0042] In the present invention, the auxiliary material Ca y Sm 2 / 3(1-y) The preparation method of TiO3 preferably comprises the following steps: y Sm 2 / 3(1-y) TiO3 stoichiometric ratio CaCO3, Sm2O3 and TiO2 are mixed and calcined for the third time to obtain the auxiliary material Ca y Sm 2 / 3(1-y) In the present invention, the purity of CaCO3, Sm2O3 and TiO2 is preferably above 99wt%. In the present invention, the mixing method of CaCO3, Sm2O3 and TiO2 is preferably ball milling, and the specific optional conditions of the ball milling are preferably the same as those for preparing the main material BaZn2Ti4O 11 The optional conditions for ball milling and mixing are the same and will not be described here. In the present invention, the ball milling and mixing preferably further include drying and sieving in sequence; the specific optional conditions for drying and sieving are preferably the same as those for preparing the main material BaZn2Ti4O 11 The optional conditions for drying and sieving are the same and will not be described in detail. In the present invention, the temperature of the third calcination is preferably 1100-1200°C, more preferably 1140-1150°C; the holding time is preferably 2-4h, more preferably 2.5-3.5h.

[0043] In terms of mass percentage, the components of the microwave ceramic material of the present invention include 0.07% to 0.27% of sintering aid, for example, it can be 0.07%, 0.10%, 0.13%, 0.16%, 0.18%, 0.21%, 0.23%, 0.25%, 0.26% or 0.27%. In the present invention, the sintering aid is preferably Ca-Al-Si system glass. In an embodiment of the present invention, the sintering aid is purchased from Foshan Jinggu Material Technology Co., Ltd., model FJ1219A.

[0044] Calculated by mass percentage, the components of the microwave ceramic material of the present invention include 0.03% to 0.05% of MnO2, for example, specifically 0.03%, 0.04% or 0.05%.

[0045] Calculated by mass percentage, the components of the microwave ceramic material of the present invention include Dy2O30.52% to 2.03%, for example, it can be 0.52%, 0.60%, 0.70%, 0.80%, 0.94%, 0.95%, 1.02%, 1.04%, 1.10%, 1.30%, 1.50%, 1.70%, 1.77%, 1.80%, 1.83%, 1.90% or 2.03%.

[0046] The present invention uses BaZn2Ti4O as main material 11 As the matrix material, the auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 And the auxiliary material Ca y Sm 2 / 3(1-y) TiO3, MnO2 and Dy2O3 are used as additives to adjust the comprehensive performance of microwave ceramic materials, and the addition of sintering aids is conducive to reducing the sintering temperature of microwave ceramic materials, ensuring that the microwave ceramic materials can meet the preparation and use requirements of MLCC. Specifically, the present invention designs the microwave ceramic material formula according to the summation law of multiphase ceramic properties shown in the following formula:

[0047] lnε r =V1lnε1+V2lnε2 Formula 1;

[0048] Q -1 =V1Q1 -1 +V2Q2 -1 Formula 2;

[0049] τ f =V1τ f1 +V2τ f2 Formula 3;

[0050] In formula 1, V1 and V2 represent the volume fraction of each phase, and ε1 and ε2 represent the dielectric constant of each phase;

[0051] In formula 2, Q1 and Q2 represent the quality factor of each phase respectively;

[0052] In formula 3, τ f1 and τ f2 Represents the temperature coefficient of each phase.

[0053] In the present invention, the auxiliary material Ba (Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 and auxiliary material Ca y Sm 2 / 3(1-y)TiO3 has a large dielectric constant, among which the auxiliary material Ca y Sm 2 / 3(1-y) TiO3 has the same 11 The temperature coefficient has an opposite sign, which complements the performance of the base material and can effectively adjust the dielectric constant and temperature coefficient of the microwave ceramic material. After optimizing the formula ratio, the dielectric constant of the microwave ceramic material is about 30, and the temperature coefficient can be adjusted to near zero. When the present invention adds a sintering aid and uses microwave ceramic materials to prepare MLCC, the sintering aid will form a liquid phase during the sintering process to accelerate the mass transfer process, reduce the sintering temperature, and promote sintering densification and grain growth. However, excessive addition will cause abnormal grain growth, increase the dielectric loss of the microwave ceramic material, and reduce the strength of the porcelain body. The addition of MnO2 in the present invention can improve the Q value of the microwave ceramic material to a certain extent. This is because Mn 4+ Suppresses the Ti 4+ The valence of Dy2O3 is changed, thereby reducing the loss. However, excessive addition may cause the insulation resistance of the microwave ceramic material to decrease, thereby reducing the reliability of the prepared capacitor. The additive Dy2O3 of the present invention can refine the ceramic grain size and improve the bending strength of the microwave ceramic material to a certain extent; at the same time, the grain refinement makes the microwave ceramic material produce more grain boundaries during sintering, and the grain boundaries will hinder the passage of electrons, which is beneficial to the improvement of the insulation resistance of the microwave ceramic material.

[0054] The present invention provides a method for preparing the microwave ceramic material described in the above technical solution, comprising the following steps:

[0055] The main material BaZn2Ti4O 11 、Auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 、Auxiliary material Ca y Sm 2 / 3(1-y) TiO3, sintering aid, MnO2 and Dy2O3 are mixed to obtain the microwave ceramic material.

[0056] In the present invention, the main material BaZn2Ti4O 11 、Auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 、Auxiliary material Ca y Sm 2 / 3(1-y)The mixing method of TiO3, sintering aid, MnO2 and Dy2O3 is preferably ball milling, and the ball milling is preferably carried out in the presence of water and ball milling medium, the water is preferably deionized water, and the ball milling medium is preferably zirconia balls; the rotation speed of the ball milling is preferably 150-400rpm, more preferably 300rpm; the time is preferably 5-10h, more preferably 5.5-8h. In the present invention, the ball milling preferably also includes drying and screening in sequence after the ball milling; the drying temperature is preferably 110-125°C, more preferably 115-120°C; the time is preferably 5-7h, more preferably 5.5-6h; the mesh number of the sieve used for screening is preferably 40-60 mesh, more preferably 50-60 mesh; the material under the sieve collected after screening is the microwave ceramic material.

[0057] The present invention provides the application of the microwave ceramic material described in the above technical solution or the microwave ceramic material prepared by the preparation method described in the above technical solution in microwave components. In the present invention, the microwave components preferably include capacitors, microwave substrates, resonators, filters or dielectric antennas; the capacitors preferably include chip-type multilayer ceramic capacitors or single-layer ceramic capacitors (SLCC); the preparation process of the chip-type multilayer ceramic capacitors preferably includes porcelain slurry preparation, cast film, printing internal electrodes, lamination, uniform pressing, cutting, debonding, sintering, chamfering, coating ends and sintering ends; wherein the raw materials for preparing the porcelain slurry in the porcelain slurry preparation process include the microwave ceramic material provided by the present invention; the metal material used for the internal electrode in the printing internal electrode process is preferably a silver-palladium material (that is, the internal electrode is preferably a silver-palladium internal electrode); the sintering temperature is preferably 1080-1120°C, more preferably 1100-1110°C, and the holding time is preferably 2-5h, more preferably 3-4h. The microwave ceramic material of the present invention has excellent comprehensive performance under the condition of relatively low sintering temperature (1080-1120° C.), and can meet the requirements for preparing highly reliable and temperature-stable MLCC.

[0058] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] Examples 1 to 16 and Comparative Examples 1 to 5

[0060] Main material: BaZn2Ti4O 11 Preparation: According to BaZn2Ti4O 11BaCO3, ZnO and TiO2 with a purity of more than 99wt% were weighed in a stoichiometric ratio and mixed. Deionized water and ball milling media (specifically zirconium oxide balls) were added to the obtained mixed raw materials for ball milling (rotation speed of 300rpm, time of 3.5h). After the ball milling, the obtained material was dried (temperature of 115°C, time of 6.5h) and sieved (the mesh size of the sieve used was 60 meshes), and calcined at 1070°C for 2.5h to obtain the main material BaZn2Ti4O 11 ;

[0061] Auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 Preparation of (0.5≤x≤0.7): According to Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 BaCO3, Sm2O3, Nd2O3 and TiO2 with a purity of more than 99wt% were weighed in a stoichiometric ratio and mixed. Deionized water and ball milling media (specifically zirconium oxide balls) were added to the obtained mixed raw materials for ball milling (rotation speed of 300rpm, time of 3.5h). After the ball milling, the obtained material was dried (temperature of 115°C, time of 6.5h) and sieved (the mesh size of the sieve used was 60 mesh), and calcined at 1110°C for 2.5h to obtain the auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 ;

[0062] Auxiliary material Ca y Sm 2 / 3(1-y) Preparation of TiO3 (0.5≤y≤0.8): According to Ca y Sm 2 / 3(1-y) CaCO3, Sm2O3 and TiO2 with a purity of more than 99wt% were weighed and mixed in a stoichiometric ratio. Deionized water and ball milling media (specifically zirconium oxide balls) were added to the obtained mixed raw materials for ball milling (rotation speed of 300rpm, time of 3.5h). After the ball milling, the obtained material was dried (temperature of 115°C, time of 6.5h) and sieved (the mesh size of the sieve used was 60 meshes), and calcined at 1140°C for 2.5h to obtain the auxiliary material Ca y Sm 2 / 3(1-y) TiO3;

[0063] Preparation of microwave ceramic materials: The main material BaZn2Ti4O 11 、Auxiliary material Ba(Sm x Nd1-x ) 2.3 Ti 4.5 O 13.45 、Auxiliary material Ca y Sm 2 / 3(1-y) TiO3 is mixed with a sintering aid (specifically Ca-Al-Si system glass) and a modified additive (specifically MnO2 and Dy2O3), and deionized water and a ball milling medium (specifically zirconia balls) are added to the obtained mixed raw material for ball milling (rotation speed of 300rpm, time of 5.5h), and after the ball milling, the obtained material is dried (temperature of 120°C, time of 6h) and sieved (the mesh number of the sieve used is 60 meshes), and the material under the sieve is collected as the microwave ceramic material. The formula of the microwave ceramic material in each embodiment and comparative example is specifically shown in Table 1.

[0064] Table 1 Formula of microwave ceramic materials in various embodiments and comparative examples (mass percentage %)

[0065]

[0066] Test Case

[0067] The dielectric properties of the microwave ceramic materials in each embodiment and comparative example were tested in the following steps:

[0068] A 10wt% polyvinyl butyral (PVB) solution is used as a binder, a microwave ceramic material and the binder are mixed and granulated, and then pressed into a disc blank under a pressure of 4MPa, the disc blank is heated from room temperature to 450°C at a heating rate of 3°C / min, and the binder is removed at 450°C for 3h to remove the binder, thereby obtaining a debinding blank; the debinding blank is sintered at 1100°C for 3h, and after sintering, it is naturally cooled to room temperature with the furnace to obtain a sintered blank;

[0069] Silver paste was coated on the upper and lower surfaces of the sintered green body, and then the green body was heat-treated at 780°C for 0.5h, and naturally cooled to room temperature with the furnace to obtain a silver electrode. The dielectric properties were tested after being placed for 24h. The specific test results are shown in Table 2, where the dielectric constant, dielectric loss and room temperature insulation resistivity of the samples were tested at 25°C±3°C.

[0070] Table 2 Performance test results of silver electrodes prepared from microwave ceramic materials in various embodiments and comparative examples

[0071]

[0072]

[0073] It can be seen from Table 2 that the addition of auxiliary materials will increase the dielectric constant of microwave ceramic materials. This is because the auxiliary material Ba (Smx Nd 1-x ) 2.3 Ti 4.5 O 13.45 and Ca y Sm 2 / 3(1-y) TiO3 itself has a high dielectric constant, which helps to increase the dielectric constant of the matrix material according to the performance addition law. Moreover, within the range of -55 to +125°C, with the auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 As the content increases, the temperature coefficient becomes positive, and as the auxiliary material Ca y Sm 2 / 3(1-y) As the TiO3 content increases, the temperature coefficient shifts to the negative direction, which is related to the microwave dielectric properties of the auxiliary material itself. Therefore, the addition of the auxiliary material helps to improve the dielectric constant of microwave ceramic materials and regulate the temperature coefficient. At the same time, by adding rare earth Dy2O3, the insulation resistivity of microwave ceramic materials is higher, and the room temperature and high temperature insulation resistivity both reach 10 14 Ω·cm, which can ensure high reliability in its application. In addition, by adding sintering aids, the sintering temperature is reduced from 1200℃ to 1100℃, which is convenient for matching the silver-palladium internal electrode in MLCC.

[0074] Figure 1 This is the SEM image of the microwave ceramic material (formula number 11) in Example 9 after sintering at 1100°C for 3 hours, where (a) is a surface morphology image and (b) is a cross-sectional morphology image. From (a), it can be seen that there are many small grains on the surface of the microwave ceramic material after sintering at 1100°C, and from (b), it can be seen that the microwave ceramic material has good density after sintering at 1100°C. Combined with the performance test results in Table 2, it can be seen that the microwave ceramic material provided by the present invention can meet the requirements for preparing high-reliability and temperature-stable MLCC.

[0075] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A microwave ceramic material, characterized in that: Calculated by mass percentage, it includes the following components: Main material: BaZn2Ti4O 11 85.50%~92.00%; Auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 0.74% to 7.95%, 0.50 ≤ x ≤ 0.70; Auxiliary material Ca y Sm 2 / 3(1-y) TiO33.00%~6.13%, 0.50≤y≤0.80; Sintering aid 0.07%~0.27%; MnO2 0.03%~0.05%; Dy2O30.52%~2.03%.

2. The microwave ceramic material according to claim 1, characterized in that: The main material BaZn2Ti4O 11 The preparation method comprises the following steps: According to the main material BaZn2Ti4O 11 BaCO3, ZnO and TiO2 are mixed in a stoichiometric ratio and calcined for the first time to obtain the main material BaZn2Ti4O 11 .

3. The microwave ceramic material according to claim 2, characterized in that: The temperature of the first calcination is 1050-1100° C., and the holding time is 2-4 hours.

4. The microwave ceramic material according to claim 1, characterized in that: The auxiliary material Ba (Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 The preparation method comprises the following steps: According to the auxiliary material Ba (Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 BaCO3, Sm2O3, Nd2O3 and TiO2 are mixed in a stoichiometric ratio and subjected to a second calcination to obtain the auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 .

5. The microwave ceramic material according to claim 4, characterized in that: The temperature of the second calcination is 1090-1150° C., and the holding time is 2-4 hours.

6. The microwave ceramic material according to claim 1, characterized in that: The auxiliary material Ca y Sm 2 / 3(1-y) The preparation method of TiO3 comprises the following steps: According to the auxiliary material Ca y Sm 2 / 3(1-y) TiO3 stoichiometric ratio CaCO3, Sm2O3 and TiO2 are mixed and calcined for the third time to obtain the auxiliary material Ca y Sm 2 / 3(1-y) TiO3.

7. The microwave ceramic material according to claim 6, characterized in that: The temperature of the third calcination is 1100-1200° C., and the insulation time is 2-4 hours.

8. The method for preparing the microwave ceramic material according to any one of claims 1 to 7, characterized in that: The following steps are involved: The main material BaZn2Ti4O 11 、Auxiliary material Ba(Sm x Nd 1-x ) 2.3 Ti 4.5 O 13.45 、Auxiliary material Ca y Sm 2 / 3(1-y) TiO3, sintering aid, MnO2 and Dy2O3 are mixed to obtain the microwave ceramic material.

9. Use of the microwave ceramic material according to any one of claims 1 to 7 or the microwave ceramic material prepared by the preparation method according to claim 8 in microwave components.

10. The use according to claim 9, characterized in that: The microwave components include capacitors, microwave substrates, resonators, filters or dielectric antennas.

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