Microwave dielectric material and method for preparing the same

Abstract

The application belongs to the technical field of microwave dielectric materials, and provides a microwave dielectric material and a preparation method thereof, wherein the raw materials for preparing the microwave dielectric material include a first main material, a second main material and an additive; the first main material includes (Ca x Nd (2‑2x) / 3 )TiO3, and x is 0.7-0.95; the second main material includes (Mg 1‑y Zn y )TiO3, and y is 0.15-0.55; and the additive includes glass powder. The microwave dielectric material has the advantages of low sintering temperature, low dielectric loss, stable dielectric constant and stable temperature coefficient in a specific range by using specific first and second main materials and introducing glass powder.

Description

Technical Field

[0001] This invention belongs to the field of microwave dielectric materials technology, and relates to a microwave dielectric material and its preparation method. Background Technology

[0002] The development and manufacturing of MLCCs (multilayer ceramic chip capacitors) has been slow due to limitations in materials, equipment, and processes. The reliability of the core microwave dielectric material in MLCCs, along with thinning, multilayering processes and co-firing techniques with metal electrodes, jointly determines the size, capacitance, and performance stability of downstream MLCC products. Currently, the CaTiO3-MgTiO3 system microwave dielectric material disclosed in existing technologies suffers from high sintering temperatures (exceeding 1250℃). These high temperatures not only disrupt the co-firing compatibility between the inner electrode and the dielectric layer but also lead to performance degradation and structural defects in the dielectric layer. Furthermore, they significantly increase process costs and scrap rates, ultimately preventing products from meeting the requirements of high-end applications such as consumer electronics and new energy vehicles. In addition, existing microwave dielectric materials exhibit high dielectric losses, and their dielectric constant and temperature coefficient are difficult to meet requirements.

[0003] Based on the above research, there is a need to provide a microwave dielectric material with low sintering temperature, low dielectric loss, and dielectric constant and temperature coefficient within a specific range. Summary of the Invention

[0004] The purpose of this invention is to provide a microwave dielectric material and its preparation method. The microwave dielectric material, by using specific first and second main materials and introducing glass powder, has the advantages of low sintering temperature, low dielectric loss, and dielectric constant and temperature coefficient within a specific range.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a microwave dielectric material, wherein the raw materials for preparing the microwave dielectric material include a first main material, a second main material, and additives;

[0007] The first main material includes (Ca) x Nd (2-2x) / 3 TiO3, x is 0.7~0.95;

[0008] The second main material includes (Mg) 1-y Zn y TiO3, y is 0.15~0.55;

[0009] The additives include glass powder.

[0010] Preferably, the first main material includes (Ca) x Nd (2-2x) / 3TiO3, x is 0.85~0.95.

[0011] Preferably, the second main material includes (Mg) 1-y Zn y TiO3, y is 0.3~0.46.

[0012] Preferably, the molar ratio of the first main material to the second main material is A:(100-A), where A is 7~10.

[0013] Preferably, the mass of the additive is 3wt% to 9wt% of the total mass of the first main material and the second main material.

[0014] Preferably, the mass of the additive is 6wt% to 8wt% of the total mass of the first main material and the second main material.

[0015] Preferably, the glass powder includes Li2O-BaO-B2O3-SiO2 glass powder or Li2O-BaO-B2O3-SiO2-Al2O3 glass powder.

[0016] Preferably, the dielectric constant of the microwave dielectric material is 19-25, the dielectric loss is <0.0001, the temperature coefficient is -30ppm / ℃ < +30ppm / ℃, and the sintering temperature is ≤1150℃.

[0017] In a second aspect, the present invention provides a method for preparing a microwave dielectric material as described in the first aspect, the method comprising the following steps:

[0018] The first main material, the second main material, and the additives are ball-milled and mixed to obtain a mixture. The mixture is dried, sieved, and pressed into shape. The pressed shape is then sintered to obtain the microwave dielectric material.

[0019] Preferably, the sintering temperature is 940℃~1020℃, and the sintering time is 2h~6h.

[0020] Preferably, the raw materials for preparing the additive include Ba source, Li source, B source, Si source and Al source in a mass ratio of (45~65):(15~25):(5~20):(7~18):(0~2).

[0021] Preferably, the method for preparing the additive includes the following steps: mixing and melting Ba source, Li source, B source, Si source and Al source, then water quenching and ball milling to obtain the glass powder.

[0022] Preferably, the melting temperature is 1100℃~1200℃, and the particle size D50 of the obtained glass powder is 0.8μm~1.2μm.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention, by employing specific first and second main materials and introducing glass powder, can lower the sintering temperature, increase the density of the dielectric layer, improve the compatibility between the electrode and the dielectric, and achieve extremely low loss while achieving low-temperature sintering, reaching or even surpassing other high-temperature systems. When sintering in an air atmosphere, it can be co-fired with 95% silver-palladium electrodes. Compared with the high palladium content electrodes required by other high-temperature systems, it significantly reduces electrode costs. Furthermore, compared with copper and nickel electrodes, the sintering atmosphere is simpler, more stable, and less prone to oxidation. Detailed Implementation

[0025] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0026] In a first aspect, the present invention provides a microwave dielectric material, wherein the raw materials for preparing the microwave dielectric material include a first main material, a second main material, and additives;

[0027] The first main material includes (Ca) x Nd (2-2x) / 3 TiO3, x is 0.7~0.95;

[0028] The second main material includes (Mg) 1-y Zn y TiO3, y is 0.15~0.55;

[0029] The additives include glass powder.

[0030] The microwave dielectric material described in this invention uses (Ca) as a raw material. x Nd (2-2x) / 3 TiO3 and (Mg 1-y Zn y TiO3, as the main material, can produce stable dielectric properties in the microwave band, with a high dielectric constant and a low dielectric temperature coefficient; wherein, the (Ca) x Nd (2-2x) / 3 TiO3 contains a specific molar amount of Nd, which can refine the dielectric grains and further improve the interfacial bonding strength. Furthermore, this specific molar amount of Nd is fundamental to maintaining a stable temperature coefficient. The (Mg) 1-y Zn y TiO3 contains a specific molar amount of Zn, which can synergistically enhance sintering, reduce sintering temperature characteristics, improve grain size uniformity, reduce porosity and defects, and help reduce losses and improve Q value.

[0031] This invention uses glass powder as an additive, which can reduce the sintering temperature and dielectric loss, while also increasing the density of the dielectric layer and improving the compatibility between the electrode and the dielectric. Therefore, this invention can obtain microwave dielectric materials with low sintering temperature, low dielectric loss, and dielectric constant and temperature coefficient within a specific range by using specific main materials and additives.

[0032] The first main material of the present invention includes (Ca) x Nd (2-2x) / 3 TiO3, x is 0.7~0.95 (preferably 0.8~0.95), for example, it can be 0.7, 0.75, 0.8, 0.85, 0.9 or 0.95, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0033] The present invention uses a specific first main material, wherein if x is too small and the proportion of Nd is too large, or if x is too large and the proportion of Nd is too small, the temperature coefficient will be affected.

[0034] The second main material of this invention includes (Mg) 1-y Zn y TiO3, where y is 0.15~0.55 (preferably 0.3~0.46), for example, it can be 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5 or 0.55, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0035] This invention uses a specific second main material. If y is too small, the proportion of Zn is too low, or if y is too large, the proportion of Zn is too high, both of which will increase losses and reduce the Q value.

[0036] In one specific embodiment, the molar ratio of the first main material and the second main material is A:(100-A), where A is 7~10, for example, it can be 7, 7.5, 8, 8.5, 9, 9.5 or 10, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0037] The first main material and the second main material of the present invention satisfy a specific molar ratio, which enables the first main material to easily form a solid solution eutectic with the second main material, thereby improving the temperature stability of the second main material without reducing other properties.

[0038] In one specific embodiment, the mass of the additive is 3wt% to 9wt% (preferably 6wt% to 8wt%) of the total mass of the first main material and the second main material. For example, it can be 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, or 9wt%, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0039] The present invention preferably adds a specific amount of glass powder to ensure that the glass powder plays its role while the main material plays its role normally, thus avoiding the problem that adding too much glass powder may have an adverse effect on the performance of the microwave dielectric material.

[0040] In one specific embodiment, the glass powder includes Li2O-BaO-B2O3-SiO2 glass powder (meaning the glass powder includes Li2O, BaO, B2O3 and SiO2), or Li2O-BaO-B2O3-SiO2-Al2O3 glass powder (meaning the glass powder includes Li2O, BaO, B2O3, SiO2 and Al2O3).

[0041] This invention uses glass powder with a specific composition, which promotes the glass powder to play a role in sintering while helping to reduce the dielectric loss of the microwave dielectric material.

[0042] In one specific embodiment, the dielectric constant of the microwave dielectric material is 19-25, for example, it can be 19, 20, 21, 22, 23, 24 or 25; the dielectric loss is <0.0001, for example, it can be 0.00009, 0.00007, 0.00005 or 0.00003; -30ppm / ℃ < temperature coefficient < +30ppm / ℃, for example, it can be -29ppm / ℃, -20ppm / ℃, -10ppm / ℃, 0ppm / ℃, +10ppm / ℃, +20ppm / ℃ or +29ppm / ℃; the sintering temperature is ≤1150℃, for example, it can be 1150℃, 1100℃, 1000℃ or 950℃, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0043] The microwave dielectric material described in this invention has low dielectric loss, dielectric constant and temperature coefficient within a specific range, and also a low sintering temperature.

[0044] In a second aspect, the present invention provides a method for preparing a microwave dielectric material as described in the first aspect, the method comprising the following steps:

[0045] The first main material, the second main material, and the additives are ball-milled and mixed to obtain a mixture. The mixture is dried, sieved, and pressed into shape. The pressed shape is then sintered to obtain the microwave dielectric material.

[0046] In one specific embodiment, the sintering temperature is 940℃~1020℃, for example, it can be 940℃, 960℃, 980℃, 1000℃ or 1020℃, and the sintering time is 2h~6h, for example, it can be 2h, 3h, 4h, 5h or 6h, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0047] In one specific embodiment, the pressing pressure is 200MPa~300MPa, for example, it can be 200MPa, 250MPa or 300MPa, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0048] In one specific embodiment, the raw materials for preparing the additive include a Ba source (such as BaCO3), a Li source (such as Li2CO3), a B source (such as B2O3), a Si source (such as SiO2), and an Al source (such as Al2O3) in a mass ratio of (45~65):(15~25):(5~20):(7~18):(0~2). For example, the ratio can be 58:20:9:12.5:0.5, 45:15:20:18:2, 60:22:10:7:1, or 50:20:15:13:2, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, with 58:20:9:12.5:0.5 being the preferred ratio.

[0049] The present invention preferably uses glass powder with raw materials that meet a specific mass ratio, which enables the glass powder to have high frequency and low loss characteristics, allowing the glass powder to perform the dual functions of assisting in sintering and reducing dielectric loss.

[0050] In one specific embodiment, the method for preparing the additive includes the following steps: mixing and melting a Ba source (such as BaCO3), a Li source (such as Li2CO3), a B source (such as B2O3), a Si source (such as SiO2), and an Al source (such as Al2O3), followed by water quenching and ball milling to obtain the glass powder.

[0051] In one specific embodiment, the melting temperature is 1100℃~1200℃, for example, it can be 1100℃, 1150℃ or 1200℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0052] In one specific embodiment, the melting time is 1h to 3h, for example, it can be 1h, 1.5h, 2h, 2.5h or 3h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0053] In one specific embodiment, the particle size D50 of the obtained glass powder is 0.8μm to 1.2μm, for example, it can be 0.8μm, 0.9μm, 1.0μm, 1.1μm or 1.2μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0054] In one specific embodiment, the method for preparing the first main material includes the following steps: according to the formula amount of the first main material, Ca source (such as CaCO3), Nd source (such as Nd2O3) and Ti source (such as TiO2) are ball-milled, dried and pre-calcined to obtain the first main material.

[0055] In one specific embodiment, when preparing the first main material, the ball milling mixing time is 1h to 3h, for example, it can be 1h, 1.5h, 2h, 2.5h or 3h; the first pre-firing temperature is 900℃ to 950℃, for example, it can be 900℃, 910℃, 920℃, 930℃, 940℃ or 950℃; and the first pre-firing time is 2.5h to 3.5h, for example, it can be 2.5h, 3h or 3.5h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0056] In one specific embodiment, the method for preparing the second main material includes the following steps: according to the formula amount of the second main material, Mg source (such as MgCO3), Zn source (such as ZnO) and Ti source (such as TiO2) are ball-milled, dried and then pre-calcined to obtain the second main material.

[0057] In one specific embodiment, when preparing the second main material, the ball milling mixing time is 1h to 3h, for example, it can be 1h, 1.5h, 2h, 2.5h or 3h; the second pre-firing temperature is 850℃ to 900℃, for example, it can be 850℃, 860℃, 870℃, 880℃, 890℃ or 900℃; and the second pre-firing time is 2.5h to 3.5h, for example, it can be 2.5h, 3h or 3.5h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0058] 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 are merely illustrative of the present invention and should not be construed as limiting the invention.

[0059] Example 1

[0060] This embodiment provides a microwave dielectric material. The raw materials for preparing the microwave dielectric material include a first main material, a second main material, and additives. The first main material is (Ca... 0.9 Nd 0.2 / 3 TiO3, the second main material is (Mg) 0.64 Zn 0.36 TiO3, wherein the additive is Li2O-BaO-B2O3-SiO2-Al2O3 glass powder;

[0061] The molar ratio of the first main material to the second main material is 8:92; the mass of the additive is 6 wt% of the total mass of the first main material and the second main material.

[0062] The method for preparing the microwave dielectric material includes the following steps:

[0063] (1) According to the formula amount of the first main material, CaCO3, Nd2O3 and TiO2 are ball-milled and mixed for 2 hours, then dried, and then pre-calcined at 900℃ for 3 hours to obtain the first main material;

[0064] According to the formula of the second main material, MgCO3, ZnO and TiO2 are ball-milled and mixed for 2 hours, then dried, and then pre-calcined at 880℃ for 3 hours to obtain the second main material;

[0065] BaCO3, Li2CO3, B2O3, SiO2 and Al2O3 were mixed in a mass ratio of 58:20:9:12.5:0.5 and then melted at 1150℃ for 2 hours. After that, the mixture was water quenched and ball milled to obtain glass powder with a particle size D50 of 1 μm.

[0066] (2) The first main material obtained in step (1), the second main material obtained in step (1) and the glass powder obtained in step (1) are ball-milled, dried and sieved, then pressed into shape under a pressure of 250 MPa, and finally sintered at a temperature of 1000℃ for 3 hours to obtain microwave dielectric material.

[0067] Example 2

[0068] This embodiment provides a microwave dielectric material. The raw materials for preparing the microwave dielectric material include a first main material, a second main material, and additives. The first main material is (Ca... 0.9 Nd 0.2 / 3 TiO3, the second main material is (Mg) 0.58 Zn 0.42 TiO3, wherein the additive is Li2O-BaO-B2O3-SiO2-Al2O3 glass powder;

[0069] The molar ratio of the first main material to the second main material is 10:90; the mass of the additive is 8 wt% of the total mass of the first main material and the second main material.

[0070] The method for preparing the microwave dielectric material includes the following steps:

[0071] (1) According to the formula amount of the first main material, CaCO3, Nd2O3 and TiO2 are ball-milled and mixed for 2 hours, then dried, and then pre-calcined at 900℃ for 3 hours to obtain the first main material;

[0072] According to the formula of the second main material, MgCO3, ZnO and TiO2 are ball-milled and mixed for 2 hours, then dried, and then pre-calcined at 880℃ for 3 hours to obtain the second main material;

[0073] BaCO3, Li2CO3, B2O3, SiO2 and Al2O3 were mixed in a mass ratio of 58:20:9:12.5:0.5 and then melted at 1200℃ for 2 hours. After that, the mixture was water quenched and ball milled to obtain glass powder with a particle size D50 of 1 μm.

[0074] (2) The first main material obtained in step (1), the second main material obtained in step (1) and the glass powder obtained in step (1) are ball-milled, dried and sieved, then pressed into shape under a pressure of 250 MPa, and finally sintered at a temperature of 940℃ for 3 hours to obtain microwave dielectric material.

[0075] Example 3

[0076] This embodiment provides a microwave dielectric material. The raw materials for preparing the microwave dielectric material include a first main material, a second main material, and additives. The first main material is (Ca... 0.9 Nd 0.2 / 3 TiO3, the second main material is (Mg) 0.54 Zn 0.46 TiO3, wherein the additive is Li2O-BaO-B2O3-SiO2-Al2O3 glass powder;

[0077] The molar ratio of the first main material to the second main material is 10:90; the mass of the additive is 7 wt% of the total mass of the first main material and the second main material.

[0078] The method for preparing the microwave dielectric material includes the following steps:

[0079] (1) According to the formula amount of the first main material, CaCO3, Nd2O3 and TiO2 are ball-milled and mixed for 2 hours, then dried, and then pre-calcined at 900℃ for 3 hours to obtain the first main material;

[0080] According to the formula of the second main material, MgCO3, ZnO and TiO2 are ball-milled and mixed for 2 hours, then dried, and then pre-calcined at 880℃ for 3 hours to obtain the second main material;

[0081] BaCO3, Li2CO3, B2O3, SiO2 and Al2O3 were mixed in a mass ratio of 58:20:9:12.5:0.5 and then melted at 1100℃ for 2 hours. After that, the mixture was water quenched and ball milled to obtain glass powder with a particle size D50 of 1 μm.

[0082] (2) The first main material obtained in step (1), the second main material obtained in step (1) and the glass powder obtained in step (1) are ball-milled, dried and sieved, then pressed into shape under a pressure of 250 MPa, and finally sintered at a temperature of 980℃ for 3 hours to obtain microwave dielectric material.

[0083] Example 4

[0084] This embodiment provides a microwave dielectric material. The raw materials for preparing the microwave dielectric material include a first main material, a second main material, and additives. The first main material is (Ca... 0.9 Nd 0.2 / 3 TiO3, the second main material is (Mg) 0.7 Zn 0.3 TiO3, wherein the additive is Li2O-BaO-B2O3-SiO2-Al2O3 glass powder;

[0085] The molar ratio of the first main material to the second main material is 7:93; the mass of the additive is 6 wt% of the total mass of the first main material and the second main material.

[0086] The method for preparing the microwave dielectric material includes the following steps:

[0087] (1) According to the formula amount of the first main material, CaCO3, Nd2O3 and TiO2 are ball-milled and mixed for 2 hours, then dried, and then pre-calcined at 900℃ for 3 hours to obtain the first main material;

[0088] According to the formula of the second main material, MgCO3, ZnO and TiO2 are ball-milled and mixed for 2 hours, then dried, and then pre-calcined at 880℃ for 3 hours to obtain the second main material;

[0089] BaCO3, Li2CO3, B2O3, SiO2 and Al2O3 were mixed in a mass ratio of 58:20:9:12.5:0.5 and then melted at 1100℃ for 2 hours. After that, the mixture was water quenched and ball milled to obtain glass powder with a particle size D50 of 1 μm.

[0090] (2) The first main material obtained in step (1), the second main material obtained in step (1) and the glass powder obtained in step (1) are ball-milled, dried and sieved, then pressed into shape under a pressure of 250 MPa, and finally sintered at a temperature of 1020℃ for 3 hours to obtain microwave dielectric material.

[0091] Example 5

[0092] This embodiment provides a microwave dielectric material. The raw materials for preparing the microwave dielectric material include a first main material, a second main material, and additives. The first main material is (Ca... 0.85 Nd 0.1 TiO3, the second main material is (Mg) 0.64 Zn 0.36 TiO3, wherein the additive is Li2O-BaO-B2O3-SiO2-Al2O3 glass powder;

[0093] The molar ratio of the first main material to the second main material is 7:93; the mass of the additive is 3 wt% of the total mass of the first main material and the second main material.

[0094] The method for preparing the microwave dielectric material includes the following steps:

[0095] (1) According to the formula amount of the first main material, CaCO3, Nd2O3 and TiO2 are ball-milled and mixed for 3h, then dried, and then pre-calcined at 900℃ for 3.5h to obtain the first main material;

[0096] According to the formula of the second main material, MgCO3, ZnO and TiO2 are ball-milled and mixed for 1 hour, then dried, and then pre-calcined at 900℃ for 3.5 hours to obtain the second main material;

[0097] BaCO3, Li2CO3, B2O3, SiO2 and Al2O3 were mixed in a mass ratio of 45:15:20:18:2 and then melted at 1100℃ for 3 hours. After that, the mixture was water quenched and ball milled to obtain glass powder with a particle size D50 of 1.2 μm.

[0098] (2) The first main material obtained in step (1), the second main material obtained in step (1) and the glass powder obtained in step (1) are ball-milled, dried and sieved, then pressed into shape under a pressure of 300 MPa, and finally sintered at a temperature of 1020℃ for 6 hours to obtain microwave dielectric material.

[0099] Example 6

[0100] This embodiment provides a microwave dielectric material. The raw materials for preparing the microwave dielectric material include a first main material, a second main material, and additives. The first main material is (Ca... 0.95 Nd 0.1 / 3 TiO3, the second main material is (Mg) 0.64 Zn 0.36 TiO3, wherein the additive is Li2O-BaO-B2O3-SiO2-Al2O3 glass powder;

[0101] The molar ratio of the first main material to the second main material is 10:90; the mass of the additive is 9 wt% of the total mass of the first main material and the second main material.

[0102] The method for preparing the microwave dielectric material includes the following steps:

[0103] (1) According to the formula amount of the first main material, CaCO3, Nd2O3 and TiO2 are ball-milled and mixed for 1 hour, then dried, and then pre-calcined at 950°C for 2.5 hours to obtain the first main material;

[0104] According to the formula of the second main material, MgCO3, ZnO and TiO2 are ball-milled and mixed for 3 hours, then dried, and then pre-calcined at 850℃ for 2.5 hours to obtain the second main material;

[0105] BaCO3, Li2CO3, B2O3, SiO2 and Al2O3 were mixed in a mass ratio of 65:22.5:5:7:0.5 and then melted at 1200℃ for 1 hour. After that, the mixture was water quenched and ball milled to obtain glass powder with a particle size D50 of 0.8 μm.

[0106] (2) The first main material obtained in step (1), the second main material obtained in step (1) and the glass powder obtained in step (1) are ball-milled, dried and sieved, then pressed into shape under a pressure of 200 MPa, and finally sintered at a temperature of 940℃ for 2 hours to obtain microwave dielectric material.

[0107] Example 7

[0108] This embodiment provides a microwave dielectric material, wherein the raw materials for preparing the microwave dielectric material, in addition to the first main material being (Ca), are (Ca). 0.7 Nd 0.2 Except for TiO3, everything else is the same as in Example 1.

[0109] The preparation method of the microwave dielectric material described in this embodiment is the same as that in Embodiment 1, except for the adaptive change in the formulation amount of the first main material.

[0110] Example 8

[0111] This embodiment provides a microwave dielectric material, wherein the raw materials for preparing the microwave dielectric material, except that the second main material is (Mg) 0.85 Zn 0.15 Except for TiO3, everything else is the same as in Example 1.

[0112] The preparation method of the microwave dielectric material described in this embodiment is the same as that in Example 1, except for the adaptive change in the formulation amount of the second main material.

[0113] Example 9

[0114] This embodiment provides a microwave dielectric material, wherein the raw materials for preparing the microwave dielectric material, except that the second main material is (Mg) 0.45 Zn 0.55 Except for TiO3, everything else is the same as in Example 1.

[0115] The preparation method of the microwave dielectric material described in this embodiment is the same as that in Example 1, except for the adaptive change in the formulation amount of the second main material.

[0116] Example 10

[0117] This embodiment provides a microwave dielectric material. The raw materials for preparing the microwave dielectric material are the same as those in Embodiment 1, except that the molar ratio of the first main material and the second main material is 5:95.

[0118] The preparation method of the microwave dielectric material described in this embodiment is the same as that in Example 1, except for the adaptive change in the formulation amount of the raw materials.

[0119] Example 11

[0120] This embodiment provides a microwave dielectric material. The raw materials for preparing the microwave dielectric material are the same as those in Embodiment 1, except that the molar ratio of the first main material and the second main material is 12:88.

[0121] The preparation method of the microwave dielectric material described in this embodiment is the same as that in Example 1, except for the adaptive change in the formulation amount of the raw materials.

[0122] Example 12

[0123] This embodiment provides a microwave dielectric material. The raw materials for preparing the microwave dielectric material are the same as those in Embodiment 1, except that the mass of the additive is 2 wt% of the total mass of the first main material and the second main material.

[0124] The preparation method of the microwave dielectric material described in this embodiment is the same as that in Example 1, except for the adaptive change in the formulation amount of the raw materials.

[0125] Example 13

[0126] This embodiment provides a microwave dielectric material. The raw materials for preparing the microwave dielectric material are the same as those in Embodiment 1, except that the mass of the additive is 10 wt% of the total mass of the first main material and the second main material.

[0127] The preparation method of the microwave dielectric material described in this embodiment is the same as that in Example 1, except for the adaptive change in the formulation amount of the raw materials.

[0128] Example 14

[0129] This embodiment provides a microwave dielectric material. Except for the preparation method, in which the mass ratio of the raw materials BaCO3, Li2CO3, B2O3, SiO2 and Al2O3 used to prepare the glass powder is 75:13:4:5:3, which makes the microwave dielectric material adaptable, the rest of the microwave dielectric material is the same as in Embodiment 1.

[0130] Example 15

[0131] This embodiment provides a microwave dielectric material. Except for the preparation method, in which the mass ratio of the raw materials BaCO3, Li2CO3, B2O3, SiO2 and Al2O3 used to prepare the glass powder is 40:30:10:20:0, which makes the microwave dielectric material adaptable to changes, the rest of the microwave dielectric material is the same as in Embodiment 1.

[0132] Comparative Example 1

[0133] This comparative example provides a microwave dielectric material, the raw materials for which are the same as those in Example 1, except that they do not include glass powder.

[0134] The preparation method of the microwave dielectric material described in this comparative example is the same as that in Example 1, except that the formulation of the raw materials is adapted to change and the sintering temperature is 1220°C.

[0135] Comparative Example 2

[0136] This comparative example provides a microwave dielectric material, wherein the raw materials for preparing the microwave dielectric material, in addition to the first main material being (Ca), are (Ca). 0.6 Nd 0.8 / 3 Except for TiO3, everything else is the same as in Example 1.

[0137] The preparation method of the microwave dielectric material described in this comparative example is the same as that in Example 1, except for the adaptive change in the formulation amount of the first main material.

[0138] Comparative Example 3

[0139] This comparative example provides a microwave dielectric material, wherein the raw materials for preparing the microwave dielectric material, in addition to the first main material being (Ca), are (Ca). 0.99 Nd 0.02 / 3 Except for TiO3, everything else is the same as in Example 1.

[0140] The preparation method of the microwave dielectric material described in this comparative example is the same as that in Example 1, except for the adaptive change in the formulation amount of the first main material.

[0141] Comparative Example 4

[0142] This comparative example provides a microwave dielectric material, wherein the raw materials for preparing the microwave dielectric material, except for the second main material, are (Mg) 0.9 Zn 0.1 Except for TiO3, everything else is the same as in Example 1.

[0143] The preparation method of the microwave dielectric material described in this comparative example is the same as that in Example 1, except for the adaptive change in the formulation amount of the second main material.

[0144] Comparative Example 5

[0145] This comparative example provides a microwave dielectric material, wherein the raw materials for preparing the microwave dielectric material, except for the second main material, are (Mg) 0.3 Zn 0.7 Except for TiO3, everything else is the same as in Example 1.

[0146] The preparation method of the microwave dielectric material described in this comparative example is the same as that in Example 1, except for the adaptive change in the formulation amount of the second main material.

[0147] In the above embodiments and comparative examples, the chemical formula of the first main material, the chemical formula of the second main material, the molar ratio of the first main material and the second main material, the amount of glass powder added, the mass ratio of glass powder raw materials (mass ratio of BaCO3, Li2CO3, B2O3, SiO2 and Al2O3), and the sintering temperature are shown in Table 1.

[0148] The microwave dielectric materials described in the above embodiments and comparative examples were prepared by printing 95% silver-palladium electrodes on their end faces and holding them at 800℃ for 15 minutes. Dielectric performance was tested using a Tonghui TH2838A LCR meter at 1MHz. The temperature coefficient was measured using a Julang meter, with a test temperature range of -55~125℃. The capacitance and dielectric loss values ​​were obtained at each temperature point. Using 25℃ as a reference point, the capacitance change rate at each temperature point was calculated to obtain the temperature change coefficient. The test results are shown in Table 2.

[0149] Table 1

[0150]

[0151] Table 2

[0152]

[0153] As can be seen from Tables 1 and 2 above:

[0154] As shown in Examples 1-6 and Comparative Example 1, by adding glass powder, the present invention can not only reduce the sintering temperature of the microwave dielectric material and achieve good compatibility with 95% silver-palladium electrodes, but also reduce dielectric loss while ensuring that the dielectric constant and temperature coefficient are within a specific range. As shown in Examples 1 and Comparative Examples 2-3, the first main material of the present invention must meet a specific chemical formula. As shown in Examples 1 and Comparative Examples 4-5, the second main material of the present invention must meet a specific chemical formula to ensure the synergistic effect of the first main material, the second main material, and the glass powder, thus guaranteeing the comprehensive performance of the microwave dielectric material. As shown in Examples 1 and 7, in the chemical formula of the first main material of the present invention, x is preferably within a specific range to promote its optimal effect. As can be seen from Examples 1 and 8-9, in the second main material of the present invention, y is preferably within a specific range to promote the optimal effect of the second main material; as can be seen from Examples 1 and 10-11, the molar ratio of the first main material and the second main material of the present invention affects the performance of their combined effect, and is preferably within a specific range to further improve the comprehensive performance of the microwave dielectric material; as can be seen from Examples 1 and 12-13, the amount of glass powder added in the present invention is preferably within a specific range to promote its optimal effect; as can be seen from Examples 1 and 14-15, the raw materials for preparing the glass powder are preferably within a specific mass ratio range, which is beneficial for the glass powder to have high-frequency and low-loss characteristics, thereby further improving the comprehensive performance of the microwave dielectric material.

[0155] 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 microwave dielectric material, characterized in that, The raw materials for preparing the microwave dielectric material include a first main material, a second main material, and additives; The first main material includes (Ca) x Nd (2-2x) / 3 TiO3, x is 0.7~0.95; The second main material includes (Mg) 1-y Zn y TiO3, y is 0.15~0.55; The additives include glass powder.

2. The microwave dielectric material according to claim 1, characterized in that, The first main material includes (Ca) x Nd (2-2x) / 3 TiO3, x is 0.85~0.95; And / or, the second main material includes (Mg) 1-y Zn y TiO3, y is 0.3~0.46; And / or, the molar ratio of the first main material to the second main material is A:(100-A), where A is 7~10.

3. The microwave dielectric material according to claim 1 or 2, characterized in that, The mass of the additive is 3wt% to 9wt% of the total mass of the first main material and the second main material.

4. The microwave dielectric material according to claim 1 or 2, characterized in that, The mass of the additive is 6wt% to 8wt% of the total mass of the first main material and the second main material.

5. The microwave dielectric material according to claim 1 or 2, characterized in that, The glass powder includes Li2O-BaO-B2O3-SiO2 glass powder or Li2O-BaO-B2O3-SiO2-Al2O3 glass powder.

6. The microwave dielectric material according to claim 1 or 2, characterized in that, The microwave dielectric material has a dielectric constant of 19-25, a dielectric loss of <0.0001, a temperature coefficient of -30ppm / ℃ <+30ppm / ℃, and a sintering temperature of ≤1150℃.

7. A method for preparing a microwave dielectric material as described in any one of claims 1-6, characterized in that, The preparation method includes the following steps: The first main material, the second main material, and the additives are ball-milled and mixed to obtain a mixture. The mixture is dried, sieved, and pressed into shape. The pressed shape is then sintered to obtain the microwave dielectric material.

8. The preparation method according to claim 7, characterized in that, The sintering temperature is 940℃~1020℃, and the sintering time is 2h~6h.

9. The preparation method according to claim 7 or 8, characterized in that, The raw materials for preparing the additive include Ba source, Li source, B source, Si source and Al source in a mass ratio of (45~65):(15~25):(5~20):(7~18):(0~2).

10. The preparation method according to claim 9, characterized in that, The method for preparing the additive includes the following steps: mixing and melting Ba source, Li source, B source, Si source and Al source, then water quenching and ball milling to obtain the glass powder; The melting temperature is 1100℃~1200℃, and the particle size D50 of the obtained glass powder is 0.8μm~1.2μm.

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