A low temperature sintering (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic material and its preparation method and application

Abstract

The present invention provides a low temperature sintering (Eu 1‑x G x ) 2 Zr 3 (MoO 4 ) 9 The invention discloses a microwave dielectric ceramic material and a preparation method and application thereof, belonging to the field of microwave dielectric ceramic materials. 1‑x G x ) 2 Zr 3 (MoO 4 ) 9 Weigh the raw material Eu in the stoichiometric ratio 2 O 3 , Gd 2 O 3 、ZrO 2 and MoO 3 After mixing, the mixed raw material powder is ball-milled, dried, pre-sintered, and ground to obtain a mixed raw material powder; the mixed raw material powder is ball-milled, dried, pressed into a mold, and then sintered to obtain the low-temperature sintered (Eu 1‑x G x ) 2 Zr 3 (MoO 4 ) 9 Microwave dielectric ceramic materials. The prepared (Eu 1‑x G x ) 2 Zr 3 (MoO 4 ) 9 The density of ceramic is 3.16-4.03 / cm 3 It can better realize the lightweight and miniaturization of materials, and has a low dielectric constant εr=8.48 and a high quality factor Q×f=77961.1GHz, and its densification temperature is 700℃, which is lower than the melting point of silver (961℃).

Description

Technical Field

[0001] The present invention belongs to the field of microwave dielectric ceramic materials, and specifically relates to a low temperature sintered (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic material and its preparation method and application. Background Art

[0002] Microwave dielectric ceramics (MWDC), as a type of advanced ceramic material designed for microwave frequency bands (covering UHF and SHF bands, i.e. 300MHz to 300GHz, corresponding to a wavelength range of 0.1mm to 1m), play a vital role in modern communication technology. Such materials are not only used as dielectric cores to achieve resonance, filtering, construction of dielectric substrates and waveguide paths in microwave circuits, but are also the key cornerstone for promoting communication equipment to be more miniaturized, highly integrated, highly reliable and cost-effective.

[0003] The application of MWDC materials is widely used in various microwave components, such as resonators, filters, dielectric substrates and dielectric waveguides, which are the basic building blocks for building modern efficient and compact communication systems. By utilizing the unique electrical, magnetic and dielectric properties of MWDC, it can effectively meet the stringent requirements of microwave circuits for high performance, miniaturization and economy, thereby helping communication technology to continuously break through boundaries and achieve faster, more stable and wider information transmission.

[0004] Exploring new applications of microwave dielectric ceramic materials, optimizing their performance and reducing production costs have become the hot spots and focuses of current industry research. Low Temperature Co-fired Ceramics (LTCC), pioneered by Hughes in 1982, is a revolutionary material technology that cleverly uses thick film technology and multilayer ceramic co-firing design to create highly integrated, high-performance electronic packaging solutions. This technology has shown extraordinary potential in improving design freedom, optimizing wiring density and enhancing system reliability. Ideal materials for LTCC technology must meet the following stringent standards: 1. Excellent dielectric properties: The dielectric constant (εr) of the material must be controlled between 5 and 20. This range is critical for high-frequency signal transmission and helps ensure good coupling and signal integrity between electronic components. 2. Low loss characteristics: The material is required to have extremely low dielectric loss to minimize energy loss during signal transmission and improve overall system efficiency. 3. Low-temperature sintering capability: In view of the melting point limitations of internal electrode materials such as silver (Ag, melting point 961°C) and copper (Cu, melting point 1084°C), the sintering temperature of ceramic materials must be lower than the melting point of these metal electrodes to ensure that the integrity and functionality of the electrode materials are not damaged during the sintering process. 4. Good interface compatibility: There must be no interface reaction between ceramics and electrode materials, and the sintering shrinkage rates of the two must be highly matched to reduce stress concentration, crack generation, and performance degradation caused by material mismatch, thereby improving the overall stability and reliability of the packaging structure. However, the microwave dielectric materials widely used in the market currently generally have a sintering temperature higher than the melting point of electrode materials such as Cu and Ag, which greatly limits the application of LTCC technology in a wider range of fields. Therefore, finding and developing microwave dielectric materials with low sintering temperatures and meeting all the above performance requirements has become a key technical problem that needs to be solved in this field.

[0005] The main strategies for obtaining microwave dielectric ceramic materials with low dielectric constants and effective sintering at low temperatures include the following aspects: 1. Introducing sintering aids: by adding an appropriate amount of low-melting point oxides or glass phase components to the basic material system as sintering aids. These additives can form a liquid phase during the sintering process, effectively promoting the transfer and diffusion between substances, thereby significantly reducing the required sintering temperature. 2. Optimizing the synthesis method: Although the traditional solid-phase method is popular because of its simple process flow and suitability for large-scale production, the particle size distribution of the powder prepared by it is uneven, and large particles reduce the reaction activity, resulting in a high sintering temperature. Therefore, exploring more sophisticated powder preparation technology has become one of the key paths to reduce the sintering temperature. 3. Material system innovation: Directly selecting a material system with a naturally low sintering temperature characteristic is another effective way. However, this approach requires careful consideration of the compatibility of the low-melting point component with the matrix material to avoid damaging the dielectric properties of the ceramic due to the formation of a second phase by reaction. At the same time, although chemical synthesis and ultrafine powder preparation technology can provide powders with smaller particle size and more uniform distribution, thereby improving sintering efficiency, these methods are often accompanied by high technical complexity and cost, which poses a challenge to industrial promotion. In summary, the realization of microwave dielectric ceramic materials with low dielectric and low temperature sintering requires comprehensive consideration and balance in the selection of sintering aids, optimization of synthesis methods, and innovation of material systems, in order to reduce production costs and promote industrial application while maintaining excellent dielectric properties.

[0006] When developing new low-temperature sintered microwave dielectric ceramic materials, LTCC (low-temperature co-fired ceramic) technology, with its unique advantages, fits the trend of electronic products towards miniaturization, low-temperature processing, lamination and multifunctionality. It can not only realize the construction of high-density circuits in three-dimensional space and ensure that the components do not interfere with each other, but also easily create passive and active integrated functional modules or circuits, greatly expanding the possibility of application. Compared with the traditional single-layer material processing method, LTCC technology significantly improves production efficiency and effectively reduces costs, becoming one of the key technologies to promote innovation and development in the electronics industry. Summary of the invention

[0007] In view of this, the present invention aims to provide a low temperature sintering (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic material, preparation method and application thereof. The obtained microwave dielectric ceramic material has a low dielectric constant εr=8.48 and a high quality factor Q×f=77961.1GHz, and its densification temperature is 700℃.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] In the first aspect, the present invention provides a low temperature sintering (Eu1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic material, wherein x in its composition expression is 0.03-0.12.

[0010] In a second aspect, the present invention provides a method for preparing the above-mentioned low temperature sintered ceramic material, comprising the following steps:

[0011] 1) According to (Eu 1-x G x )2Zr3(MoO4)9 stoichiometric ratio of raw materials Eu2O3, Gd2O3, ZrO2 and MoO3 are weighed and mixed, and then ball milled, dried, pre-calcined and ground to obtain a mixed raw material powder;

[0012] 2) The mixed raw material powder is ball-milled, dried, pressed into shape, and sintered after being placed to obtain the low-temperature sintered (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic material.

[0013] Preferably, the purity of each raw material powder in step 1) is as follows:

[0014] The purity of Eu2O3 is 99.5%, the purity of Gd2O3 is 99.6%, the purity of ZrO2 is 99.8% and the purity of MoO3 is 99.9%. By adopting the above technical scheme, the present invention uses MoO3 to introduce molybdenum elements, which can not only accurately control the stoichiometric ratio, but also reduce the sintering temperature of the ceramic and improve the sintering characteristics.

[0015] Preferably, the pre-firing temperature in step 1) is 600° C. and the pre-firing time is 2 hours.

[0016] Preferably, the ball milling parameters in step 1) and step 2) are independently:

[0017] The ball milling media consisted of yttrium-stabilized zirconia balls with diameters of 1 mm, 5 mm, and 7 mm in a mass ratio of 3:5:2;

[0018] The ball milling aid is pure water;

[0019] The mass ratio of raw materials, ball milling media and ball milling aid is 1:2:2;

[0020] The ball milling speed is 400r / min, and the time is 23.5-24h;

[0021] The drying temperature is 90-100° C., and the drying time is 9-10 hours.

[0022] Preferably, the mesh size of the mixed raw material powder after ball milling in step 2) is 80 to 100 meshes.

[0023] Preferably, the pressure of the pressing molding in step 2) is 0.2 MPa.

[0024] Preferably, in step 2), the sintering temperature is 675-725° C. and the sintering time is 4 hours.

[0025] In a third aspect, the present invention provides an application of the above microwave dielectric ceramic material in a dielectric substrate, a resonator or a filter.

[0026] Preferably, the components prepared from the microwave dielectric ceramic material can be applied to mobile communication base stations. Dielectric resonators, dielectric filters, duplexers and multiplexers are all key components of the radio frequency unit of the communication base station.

[0027] Contains at least the following beneficial technical effects:

[0028] The present invention selects Eu2O3, Gd2O3, ZrO2 and MoO3 as raw materials to prepare microwave dielectric ceramic materials. 1-x G x )2Zr3(MoO4)9 ceramics have a density of 3.16-4.03 / cm 3 It can better realize the lightweight and miniaturization of materials, and has a low dielectric constant εr=8.48 and a high quality factor Q×f=77961.1GHz, and its densification temperature is 700℃, which is lower than the melting point of silver (961℃). BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0030] Figure 1 Prepared in Example 1 (Eu 1-x G x )XRD and SEM images of 2Zr3(MoO4)9 ceramics;

[0031] Figure 2 (Eu prepared in Example 2 1-x G x )XRD and SEM images of 2Zr3(MoO4)9 ceramics;

[0032] Figure 3 For Example 3 prepared (Eu 1-x G x )XRD and SEM images of 2Zr3(MoO4)9 ceramics;

[0033] Figure 4For the comparative example 1 prepared (Eu 1-x G x )XRD pattern of 2Zr3(MoO4)9 ceramics. DETAILED DESCRIPTION

[0034] The present invention will be described in detail below by specific examples. These examples are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. The test methods in the following examples, unless otherwise specified, are conventional methods. Unless otherwise specified, the reagents and materials used can all be obtained through commercial channels.

[0035] The purity of the raw material powders used in the following examples and comparative examples is as follows:

[0036] The purity of Eu2O3 is 99.5%, the purity of Gd2O3 is 99.6%, the purity of ZrO2 is 99.8%, and the purity of MoO3 is 99.9%.

[0037] Example 1

[0038] A low temperature sintering (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic preparation method, comprising the following steps:

[0039] (1) According to (Eu 1-x G x )2Zr3(MoO4)9, x=0.06 stoichiometric ratio, weigh Eu2O3, Gd2O3, ZrO2 and MoO3 powders and mix them, put the obtained mixture into a nylon jar with zirconium balls and pure water in a mass ratio of 1:2:2, fully ball-mill at 400r / min for 24 hours, and then dry at 100°C for 10 hours; wherein the zirconium balls are composed of yttrium-stabilized zirconia balls with diameters of 1mm, 5mm and 7mm in a mass ratio of 3:5:2; place the dried mixture in an alumina crucible, pre-sinter at 600°C for 4 hours, and then grind to obtain pre-sintered powder;

[0040] (3) adding the calcined powder, zirconium balls and pure water in a mass ratio of 1:2:2 into a nylon jar for ball milling, fully mixing and ball milling at a speed of 400 r / min for 24 hours, and drying at 100° C. for 10 hours to obtain a dry calcined powder; wherein the zirconium balls are composed of yttrium-stabilized zirconia balls with diameters of 1 mm, 5 mm and 7 mm in a mass ratio of 3:5:2;

[0041] (4) The pre-burned powder dried in step (3) was pressed into a cylindrical green body at 0.2 MPa using a powder tablet press, left to stand for 24 hours, and then sintered at 675° C. for 4 hours to obtain a low-temperature sintered (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramics.

[0042] Its XRD and SEM images are as follows Figure 1 As shown, it can be seen that the X-ray diffraction peak of the material at 675°C and x=0.06 can be determined by (Eu 1-x G x )2Zr3(MoO4)9(PDF:01-089-4364) calibration, no second phase appears, indicating that (Eu 1-x G x )2Zr3(MoO4)9 single phase. Combined with the SEM image, it can be found that when sintered at 675℃, (Eu 1-x G x )2Zr3(MoO4)9 ceramics have smaller grain size, more obvious grain boundaries, more pores, and a relatively small Q×f value.

[0043] Example 2

[0044] This embodiment provides a low temperature sintering (Eu 1-x G x The specific preparation steps of the preparation method of )2Zr3(MoO4)9 microwave dielectric ceramic are the same as those in Example 1, except that the sintering temperature in step (4) is 700°C.

[0045] Its XRD and SEM images are as follows Figure 2 As shown, it can be seen that the X-ray diffraction peak energy of the material at 700℃ and x=0.06 is consistent with (Eu 1-x G x )2Zr3(MoO4)9(PDF:01-089-4364) completely corresponds to the SEM image, and it can be found that when sintered at 700℃, (Eu 1-x G x The grain size of )2Zr3(MoO4)9 ceramics increases compared with that at 675℃, the porosity decreases, and the Q×f value increases compared with that at 675℃.

[0046] Example 3

[0047] This embodiment provides a low temperature sintering (Eu 1-x G x The specific preparation steps of the preparation method of )2Zr3(MoO4)9 microwave dielectric ceramic are the same as those in Example 1, with the only difference being that the sintering temperature in step (4) is 725°C.

[0048] Its XRD and SEM images are as follows Figure 3 As shown, it can be seen that the X-ray diffraction peak energy of the material at 725℃ and x=0.06 is consistent with (Eu 1-x G x )2Zr3(MoO4)9(PDF:01-089-4364) completely corresponds to the second phase. Combined with the SEM image, it can be found that when sintered at 725℃, (Eu 1-x G x The excessive grain growth of )2Zr3(MoO4)9 ceramics makes the chance of oxygen entering the ceramic body for reoxidation smaller and smaller, resulting in an increase in the relative content of oxygen vacancies, thereby causing a decrease in the quality factor Q×f of the ceramic.

[0049] Example 4

[0050] A low temperature sintering (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic preparation method, comprising the following steps:

[0051] (1) According to (Eu 1-x G x )2Zr3(MoO4)9, x=0.03 stoichiometric ratio, weigh Eu2O3, Gd2O3, ZrO2 and MoO3 powders and mix them, put the obtained mixture into a nylon jar with zirconium balls and pure water in a mass ratio of 1:2:2, fully ball-mill at a speed of 400r / min for 23.5 hours, and then dry at 90°C for 9 hours; wherein the zirconium balls are composed of yttrium-stabilized zirconia balls with diameters of 1mm, 5mm and 7mm in a mass ratio of 3:5:2; place the dried mixture in an alumina crucible, pre-sinter at 600°C for 4 hours, and then grind to obtain pre-sintered powder;

[0052] (3) adding the calcined powder, zirconium balls and pure water in a mass ratio of 1:2:2 into a nylon jar for ball milling, fully mixing and ball milling at a speed of 400 r / min for 23.5 hours, and drying at 90° C. for 9 hours to obtain a dry calcined powder; wherein the zirconium balls are composed of yttrium-stabilized zirconia balls with diameters of 1 mm, 5 mm and 7 mm in a mass ratio of 3:5:2;

[0053] (4) The pre-burned powder dried in step (3) was pressed into a cylindrical green body at 0.2 MPa using a powder tablet press, left to stand for 24 hours, and then sintered at 700° C. for 4 hours to obtain a low-temperature sintered (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramics.

[0054] Example 5

[0055] A low temperature sintering (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic preparation method, comprising the following steps:

[0056] (1) According to (Eu 1-x G x )2Zr3(MoO4)9, x=0.09 stoichiometric ratio, weigh Eu2O3, Gd2O3, ZrO2 and MoO3 powders and mix them, put the obtained mixture into a nylon jar with zirconium balls and pure water in a mass ratio of 1:2:2, fully ball-mill at 400r / min for 24 hours, and then dry at 100°C for 10 hours; wherein the zirconium balls are composed of yttrium-stabilized zirconia balls with diameters of 1mm, 5mm and 7mm in a mass ratio of 3:5:2; place the dried mixture in an alumina crucible, pre-sinter at 600°C for 4 hours, and then grind to obtain pre-sintered powder;

[0057] (3) adding the calcined powder, zirconium balls and pure water in a mass ratio of 1:2:2 into a nylon jar for ball milling, fully mixing and ball milling at a speed of 400 r / min for 24 hours, and drying at 100° C. for 10 hours to obtain a dry calcined powder; wherein the zirconium balls are composed of yttrium-stabilized zirconia balls with diameters of 1 mm, 5 mm and 7 mm in a mass ratio of 3:5:2;

[0058] (4) The pre-burned powder dried in step (3) was pressed into a cylindrical green body at 0.2 MPa using a powder tablet press, left to stand for 24 hours, and then sintered at 700° C. for 4 hours to obtain a low-temperature sintered (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramics.

[0059] Example 6

[0060] A low temperature sintering (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic preparation method, comprising the following steps:

[0061] (1) According to (Eu 1-x G x)2Zr3(MoO4)9, x=0.12 stoichiometric ratio, weigh Eu2O3, Gd2O3, ZrO2 and MoO3 powders and mix them, put the obtained mixture into a nylon jar with zirconium balls and pure water in a mass ratio of 1:2:2, fully ball-mill at 400r / min for 24 hours, and then dry at 100°C for 10 hours; wherein the zirconium balls are composed of yttrium-stabilized zirconia balls with diameters of 1mm, 5mm and 7mm in a mass ratio of 3:5:2; place the dried mixture in an alumina crucible, pre-sinter at 600°C for 4 hours, and then grind to obtain pre-sintered powder;

[0062] (3) adding the calcined powder, zirconium balls and pure water in a mass ratio of 1:2:2 into a nylon jar for ball milling, fully mixing and ball milling at a speed of 400 r / min for 24 hours, and drying at 100° C. for 10 hours to obtain a dry calcined powder; wherein the zirconium balls are composed of yttrium-stabilized zirconia balls with diameters of 1 mm, 5 mm and 7 mm in a mass ratio of 3:5:2;

[0063] (4) The pre-burned powder dried in step (3) was pressed into a cylindrical green body at 0.2 MPa using a powder tablet press, left to stand for 24 hours, and then sintered at 700° C. for 4 hours to obtain a low-temperature sintered (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramics.

[0064] Comparative Example 1

[0065] This comparative example provides a low temperature sintering (Eu 1-x G x The specific preparation steps of the preparation method of )2Zr3(MoO4)9 microwave dielectric ceramic are the same as those in Example 1, with the only difference being that the sintering temperature in step (4) is 600°C.

[0066] Its XRD pattern is as follows Figure 4 As shown, it can be seen that when the material is sintered at 600℃ and x=0.06, the material phase is mainly (Eu 1-x G x )2Zr3(MoO4)9, accompanied by a small amount of impurity phase and unknown phase peaks, indicating that a single phase cannot be synthesized by changing the conditions.

[0067] Experimental example

[0068] The microwave dielectric properties of the materials obtained in Examples 1-3 were tested and evaluated using a cylindrical dielectric resonator method. The test results are shown in Table 1.

[0069] Table 1 Dielectric performance test table

[0070]

[0071]

[0072] It can be seen from Table 1 that the low temperature sintering (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic density is 3.55-3.86g / cm 3 The dielectric constant εr is 8.23-9.28, and the quality factor is 46034-77961GHz. It can be widely used in the manufacture of various microwave devices such as dielectric substrates, resonators and filters, and can greatly meet the technical requirements of systems such as mobile communications and satellite communications.

[0073] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A low temperature sintering (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic material, characterized in that: In its composition expression, x is 0.03-0.

12.

2. The method for preparing a low temperature sintered ceramic material according to claim 1, characterized in that: The following steps are involved: 1) According to (Eu 1-x G x )2Zr3(MoO4)9 stoichiometric ratio of raw materials Eu2O3, Gd2O3, ZrO2 and MoO3 are weighed, mixed, ball-milled, dried, pre-calcined and ground to obtain a mixed raw material powder; 2) ball-milling the mixed raw material powder, drying it, pressing it into a shape, and then sintering it to obtain the low-temperature sintered (Eu 1-x G x )2Zr3(MoO4)9 microwave dielectric ceramic material.

3. The preparation method according to claim 2, characterized in that: The purity of each raw material powder in step 1) is as follows: The purity of Eu2O3 is 99.5%, the purity of Gd2O3 is 99.6%, the purity of ZrO2 is 99.8% and the purity of MoO3 is 99.9%.

4. The preparation method according to claim 2, characterized in that: In the step 1), the pre-firing temperature is 600° C. to 650° C., and the pre-firing time is 2 h to 4 h.

5. The preparation method according to claim 2, characterized in that: The ball milling parameters in step 1) and step 2) are independently: The ball milling media consisted of yttrium-stabilized zirconia balls with diameters of 1 mm, 5 mm, and 7 mm in a mass ratio of 3:5:2; The ball milling aid is pure water; The mass ratio of raw materials, ball milling media and ball milling aid is 1:2:2; The ball milling speed is 400r / min, and the time is 23.5-24h; The drying temperature is 90-100° C., and the drying time is 9-10 hours.

6. The preparation method according to claim 2, characterized in that: The mesh size of the mixed raw material powder after ball milling in the step 2) is 80-100 meshes.

7. The preparation method according to claim 2, characterized in that: The pressure of the pressing molding in the step 2) is 0.2 MPa.

8. The preparation method according to claim 2, characterized in that: In the step 2), the sintering temperature is 675-725° C. and the sintering time is 4 hours.

9. Use of the microwave dielectric ceramic material according to claim 1 or the microwave dielectric ceramic material prepared by the preparation method according to any one of claims 2 to 8 in a dielectric substrate, a resonator or a filter.

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