Silicon-based dielectric ceramic material with ultralow dielectric constant as well as preparation method and application of silicon-based dielectric ceramic material
By introducing core-shell structures of MgO, CaCO3 and Y2O3 into hollow amorphous SiO2-based dielectric ceramic materials, the problem of difficulty in reducing the dielectric constant of traditional silicon-based ceramic materials and prone to collapse in the hollow structure is solved, and ceramic materials with ultra-low dielectric constant and high temperature stability are achieved, which are suitable for the manufacturing of 5G communication devices.
Patent Information
- Application Number
- CN202510378045.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-28
- Publication Date
- 2025-07-01
AI Technical Summary
The dielectric constant of traditional silicon-based ceramic materials is difficult to reduce, and the hollow structure is prone to collapse during high-temperature sintering, resulting in an increase in the dielectric constant and a decrease in thermal stability, which cannot meet the high-frequency requirements of 5G communication devices.
Hollow amorphous SiO2 is used as the core layer, combined with MgO, CaCO3 and Y2O3 as the shell layers of doped materials, and hollow SiO2-based dielectric ceramic material with core-shell structure is formed. The dopant is uniformly coated through ultrasonic and ball milling processes, maintaining the hollow structure and reducing the dielectric constant.
The dielectric constant is reduced, which can reach 2~3.5 above 25GHz, has low dielectric loss, high temperature stability and good reduction resistance, and is suitable for the manufacturing of 5G communication devices.
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Figure CN120229941A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of functional ceramics, and more specifically, relates to an ultra-low dielectric constant silicon-based dielectric ceramic material, a preparation method thereof, and an application thereof. Background Art
[0002] With the rapid development of the fifth-generation mobile communication technology (5G) and the sixth-generation mobile communication technology (6G), the wide application of high-frequency bands (such as millimeter waves) and large bandwidths has put forward higher requirements for the core materials of communication devices. As a key component of devices such as high-frequency substrates, filters, and antennas, the dielectric constant of dielectric ceramic materials directly affects the delay, loss, and integration of signal transmission. To achieve high-speed and low-latency 5G communication, dielectric ceramics need to simultaneously meet the requirements of ultra-low dielectric constant (dielectric constant <5, preferably dielectric constant <3.5), low loss (<0.001), and high thermal stability (resonant frequency temperature coefficient close to zero). However, although traditional silicon-based ceramic materials (such as silica-based ceramics) have low dielectric properties, their dielectric constants are often greater than 4, and the resonant frequency temperature coefficient is less than -10 ppm / °C, making it difficult to meet the reliability requirements of high-frequency devices.
[0003] To reduce the dielectric constant, the prior art often reduces the material polarizability by introducing a porous or hollow structure. It is proposed to prepare porous ceramics by the pore-forming agent method, but the pore distribution is uneven, and the pore structure is prone to collapse during the high-temperature sintering process, resulting in the recovery of the dielectric constant. And it is easy to form through holes, which easily leads to water vapor entering the pores, affecting the working performance of the device. During the co-firing process with silver electrodes, due to the influence of the holes, silver ions will leak and diffuse, and it is impossible to prepare devices such as 5G filters by the tape casting process. During the sintering process of pure hollow SiO2, the hollow structure is extremely prone to collapse, and the grain size grows significantly. However, the contradiction between the retention and densification of the hollow structure during the high-temperature sintering process has not been effectively solved in the prior art.
[0004] With the further popularization and high-frequency development of 5G, the traditional use of silver as an electrode increases the manufacturing cost of its devices. For example, in the manufacture of LTCC high-frequency filters, theoretically, the capacitor part can be prepared using materials with high anti-reduction properties, and using base metals such as nickel as electrodes can greatly reduce the cost. However, during the co-firing matching process, requirements for the anti-reduction property of the low-dielectric constant material for preparing the inductor are also put forward. Regarding how to uniformly coat 50-100 nm matrix ceramic particles with 10-30 nm fine particles, nano-powders are extremely prone to agglomeration in air and liquid due to the interaction forces such as van der Waals force, electrostatic force, and liquid bridge force. The smaller the particle size, the more severe the agglomeration. Some researchers have proposed to use the chemical coating method, which can uniformly coat the nano-particles on the surface of the matrix, but it is difficult and costly in large-scale production. Summary of the Invention
[0005] In view of the above defects or improvement requirements of the prior art, the present invention provides an ultra-low dielectric constant silicon-based dielectric ceramic material, its preparation method and application. The purpose is to prepare a hollow SiO2-based dielectric ceramic material with a core-shell structure having a hollow amorphous SiO2 core layer and the doping material as the shell layer, thereby solving the technical problems in the prior art that the hollow structure is prone to collapse during the sintering of hollow SiO2, resulting in an increase in dielectric constant and a decrease in thermal stability.
[0006] To achieve the above object, according to one aspect of the present invention, a hollow SiO2-based dielectric ceramic material with improved dielectric constant is provided, which includes a main material and a doping material; the main material is hollow amorphous SiO2, and the doping material includes MgO, CaCO3 and Y2O3; the ceramic material has a core-shell structure with the hollow amorphous SiO2 as the core layer and the doping material as the shell layer. The improvement in dielectric constant is aimed at traditional silicon-based ceramic materials, such as silica-based ceramics, whose dielectric constant is often greater than 4.
[0007] Preferably, the molar percentages of MgO, CaCO3, Y2O3 and the hollow amorphous SiO2 are (0-2.2%):(0-2.2%):(0-2.2%):(93.4%-97.8%), and the molar percentages of MgO, CaCO3 and Y2O3 do not all take the value of 0 at the same time.
[0008] Preferably, the particle size of the hollow amorphous SiO2 is 50-100 nm, and the wall thickness is 6-16 nm; the particle sizes of MgO, CaCO3 and Y2O3 are independently selected from 10-30 nm.
[0009] According to another aspect of the present invention, a preparation method of the hollow SiO2-based dielectric ceramic material with improved dielectric constant is provided, which includes the following steps:
[0010] (1) Mix the main material and the doping material, then add deionized water and a dispersant, and then perform ultrasonic treatment, ball milling and drying in sequence to obtain ceramic powder; the main material is hollow amorphous SiO2, and the doping material includes one or more of MgO, CaCO3, Y2O3; (2) Mix the ceramic powder and a binder, and then perform granulation, sieving and pressing molding in sequence to obtain a ceramic green body; first perform debinding on the ceramic green body, and then perform sintering to obtain the hollow SiO2-based dielectric ceramic material.
[0011] Preferably, the molar percentages of the MgO, CaCO3, Y2O3, and the hollow amorphous SiO2 are (0-2.2%): (0-2.2%): (0-2.2%): (93.4%-97.8%), and the molar percentages of the MgO, CaCO3, and Y2O3 are not all 0 at the same time.
[0012] Preferably, the volume ratio of the deionized water to the dispersant is (8-15):1, preferably (10-12):1; the mass ratio of the hollow amorphous SiO2 to the deionized water is 1: (1-3).
[0013] Preferably, the dispersant is selected from polymeric phosphates.
[0014] Preferably, the binder is polyvinyl alcohol or polyvinyl butyral; the mass of the binder is 5%-40% of the mass of the ceramic powder.
[0015] Preferably, the temperature for debinding is 500-600 °C, and the holding time for debinding is 3-6 h.
[0016] Preferably, for the sintering, it is first heated to 800-900 °C and held for 0.5-2 h, then heated to 950 °C - 1100 °C, held for 1-3 h, and then slowly cooled to room temperature.
[0017] According to another aspect of the present invention, there is provided an application of the dielectric constant-improved hollow SiO2-based dielectric ceramic material as described above, which is used for the preparation of substrates, filters, or antennas in the radio frequency field of fifth-generation mobile communication technology or sixth-generation mobile communication technology.
[0018] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, the following beneficial effects can be achieved:
[0019] (1) The hollow SiO2-based dielectric ceramic material provided by the present invention uses an amorphous hollow SiO2-based powder as the matrix and MgO, CaCO3, and Y2O3 as doping materials. The ceramic material has a core-shell structure with the hollow amorphous SiO2 as the core layer and the doping materials as the shell layer. During the sintering process, it can play a role in skeleton support, reduce the collapse of the hollow structure, and at the same time can inhibit grain growth and retain the hollow structure, thereby reducing the dielectric constant of the hollow SiO2-based dielectric ceramic material, improving the temperature stability. At the same time, the addition of doping materials can improve the anti-reduction property of the ceramic material. The improvement of anti-reduction means that when manufacturing devices, base metals such as nickel and copper can be used as electrodes, greatly reducing the cost of manufacturing devices from this material.
[0020] (2) The present invention regulates the solid content of hollow amorphous SiO2 by defining the dosages of each component of hollow amorphous SiO2, MgO, CaCO3, and Y2O3; by regulating the addition amounts of the dispersant and the binder, the shrinkage curve is adjusted to maintain the hollow structure of hollow SiO2, reduce the dielectric constant and crystallization temperature, and improve the temperature stability.
[0021] (3) The present invention combines the ultrasonic method and the ball milling method with the addition of a dispersant, enabling the dopant to be uniformly coated on the surface of the hollow SiO2 matrix, thereby forming a uniform core-shell structure. Compared with the chemical coating method, this method has a simple process, is conducive to large-scale production, and has a low cost.
[0022] (4) The ultra-low dielectric constant silicon-based dielectric ceramic material provided by the present invention has a low dielectric constant, which can reach 2 - 3.5 above the frequency band of 25 GHz; it has a low dielectric loss, less than 0.0001 in the high-frequency band; the material described in the present invention has a near-zero resonance frequency temperature coefficient at 20 °C - 100 °C, and the temperature stability meets the requirements of high-frequency devices, and at the same time has good anti-reduction properties. The hollow SiO2 matrix material described in the present invention does not contain lead, is environmentally friendly; the preparation process is simple and is conducive to large-scale production. Description of the Drawings
[0023] Figure 1 It is the XRD diagram of Examples 1 - 8 and Comparative Example 1.
[0024] Figure 2 It is the SEM diagram of Example 7; where (a) is the surface of the sample polished for the first time; (b) is the surface of the sample polished for the second time; (c) is the surface of the sample polished for the third time; (d) is the surface of the sample polished for the fourth time. Detailed Embodiments
[0025] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0026] Example 1
[0027] A preparation method of a dielectric constant-improved hollow SiO2-based dielectric ceramic material, and its specific steps are as follows:
[0028] (1) Mix hollow SiO2 powder with MgO, CaCO3, and Y2O3 in a molar percentage of 99%:1%:0:0. Mix deionized water and the dispersant polyphosphate ester (BYK) in a volume ratio of 11:1 to obtain a solution. Mix the hollow SiO2 powder and the solution in a mass ratio of 1:1.5, ultrasonically disperse for 1 h, ball mill for 24 h at a rotation speed of 250 r / min, and then dry to obtain ceramic powder.
[0029] (2) Add PVA accounting for 30 wt% of the mass of the ceramic powder obtained in step (1), then granulate, screen, and mold to obtain a ceramic blank with a diameter of 12 mm and a thickness of 2 mm. The ceramic blank is heated at 2 °C / min to 550 °C for debinding for 5 h, then heated at 2 °C / min to 850 °C and held for 1 h, and then heated at 2 °C to 1000 °C and held for 2 h. Cool to room temperature at a cooling rate of 2 °C / min. Obtain a silicon-based hollow nano-ceramic matrix with ultra-low dielectric constant, low crystallization temperature, near-zero thermal expansion coefficient, and high anti-reduction property.
[0030] Example 2
[0031] A preparation method of a hollow SiO2-based dielectric ceramic material with improved dielectric constant, and the specific steps are as follows:
[0032] (1) Mix hollow SiO2 powder with MgO, CaCO3, and Y2O3 in a molar percentage of 98.5%:1.5%:0:0. Mix deionized water and the dispersant BYK in a volume ratio of 11:1 to obtain a solution. Mix the hollow SiO2 powder and the solution in a mass ratio of 1:1.5, ultrasonically disperse for 1 h, ball mill for 24 h at a rotation speed of 250 r / min, and then dry to obtain ceramic powder.
[0033] (2) Add PVA accounting for 30 wt% of the mass of the ceramic powder obtained in step (1), then granulate, screen, and mold to obtain a ceramic blank with a diameter of 12 mm and a thickness of 2 mm. The ceramic blank is heated at 2 °C / min to 550 °C for debinding for 5 h, then heated at 2 °C / min to 850 °C and held for 1 h, and then heated at 2 °C to 1000 °C and held for 2 h. Cool to room temperature at a cooling rate of 2 °C / min. Obtain a silicon-based hollow nano-ceramic matrix with ultra-low dielectric constant, low crystallization temperature, near-zero thermal expansion coefficient, and high anti-reduction property.
[0034] Example 3
[0035] A preparation method of a hollow SiO2-based dielectric ceramic material with improved dielectric constant, and the specific steps are as follows:
[0036] (1) Mix hollow SiO2 powder with MgO, CaCO3, and Y2O3 in a molar percentage of 98%:2%:0:0. Mix deionized water and dispersant BYK in a volume ratio of 11:1 to obtain a solution. Mix the hollow SiO2 powder and the solution in a mass ratio of 1:1.5, ultrasonically disperse for 1 h, ball mill for 24 h at a rotation speed of 250 r / min, and then dry to obtain ceramic powder.
[0037] (2) Add PVA accounting for 30 wt% of the mass of the ceramic powder obtained in step (1), then granulate, screen, and mold to obtain a ceramic green body with a diameter of 12 mm and a thickness of 2 mm. The ceramic green body is heated at 2 °C / min to 550 °C for debinding for 5 h, then heated at 2 °C / min to 850 °C and held for 1 h, and then heated at 2 °C to 1000 °C and held for 2 h. Cool to room temperature at a cooling rate of 2 °C / min. Obtain a silicon-based hollow nano-ceramic matrix with ultra-low dielectric constant, low crystallization temperature, near-zero thermal expansion coefficient, and high anti-reduction property.
[0038] Example 4
[0039] A preparation method of a hollow SiO2-based dielectric ceramic material with improved dielectric constant, and the specific steps are as follows:
[0040] (1) Mix hollow SiO2 powder with MgO, CaCO3, and Y2O3 in a molar percentage of 98%:0:2%:0. Mix deionized water and dispersant BYK in a volume ratio of 11:1 to obtain a solution. Mix the hollow SiO2 powder and the solution in a mass ratio of 1:1.5, ultrasonically disperse for 1 h, ball mill for 24 h at a rotation speed of 250 r / min, and then dry to obtain ceramic powder.
[0041] (2) Add PVA accounting for 30 wt% of the mass of the ceramic powder obtained in step (1), then granulate, screen, and mold to obtain a ceramic green body with a diameter of 12 mm and a thickness of 2 mm. The ceramic green body is heated at 2 °C / min to 550 °C for debinding for 5 h, then heated at 2 °C / min to 850 °C and held for 1 h, and then heated at 2 °C to 1000 °C and held for 2 h. Cool to room temperature at a cooling rate of 2 °C / min. Obtain a silicon-based hollow nano-ceramic matrix with ultra-low dielectric constant, low crystallization temperature, near-zero thermal expansion coefficient, and high anti-reduction property.
[0042] Example 5
[0043] A preparation method of a hollow SiO2-based dielectric ceramic material with improved dielectric constant, and the specific steps are as follows:
[0044] (1) Mix hollow SiO2 powder with MgO, CaCO3, and Y2O3 in a molar percentage of 98%:0:2:0. Mix deionized water and dispersant BYK in a volume ratio of 11:1 to obtain a solution. Mix the hollow SiO2 powder and the solution in a mass ratio of 1:1.5, ultrasonically disperse for 1 h, ball mill for 24 h at a rotation speed of 250 r / min, and then dry to obtain ceramic powder.
[0045] (2) Add PVA accounting for 30 wt% of the mass of the ceramic powder obtained in step (1), then granulate, screen, and mold to obtain a ceramic blank with a diameter of 12 mm and a thickness of 2 mm. The ceramic blank is heated at 2 °C / min to 550 °C for debinding for 5 h, then heated at 2 °C / min to 850 °C and held for 1 h, and then heated at 2 °C to 1075 °C and held for 2 h. Cool to room temperature at a cooling rate of 2 °C / min. Obtain a silicon-based hollow nano-ceramic matrix with ultra-low dielectric constant, low crystallization temperature, near-zero thermal expansion coefficient, and high anti-reduction property.
[0046] Example 6
[0047] A preparation method of a hollow SiO2-based dielectric ceramic material with improved dielectric constant, and its specific steps are as follows:
[0048] (1) Mix hollow SiO2 powder with MgO, CaCO3, and Y2O3 in a molar percentage of 98%:0:0:2%. Mix deionized water and dispersant BYK in a volume ratio of 11:1 to obtain a solution. Mix the hollow SiO2 powder and the solution in a mass ratio of 1:1.5, ultrasonically disperse for 1 h, ball mill for 24 h at a rotation speed of 250 r / min, and then dry to obtain ceramic powder.
[0049] (2) Add PVA accounting for 30 wt% of the mass of the ceramic powder obtained in step (1), then granulate, screen, and mold to obtain a ceramic blank with a diameter of 12 mm and a thickness of 2 mm. The ceramic blank is heated at 2 °C / min to 550 °C for debinding for 5 h, then heated at 2 °C / min to 850 °C and held for 1 h, and then heated at 2 °C to 1000 °C and held for 2 h. Cool to room temperature at a cooling rate of 2 °C / min. Obtain a silicon-based hollow nano-ceramic matrix with ultra-low dielectric constant, low crystallization temperature, near-zero thermal expansion coefficient, and high anti-reduction property.
[0050] Example 7
[0051] A preparation method of a hollow SiO2-based dielectric ceramic material with improved dielectric constant, and its specific steps are as follows:
[0052] (1) Mix hollow SiO2 powder with MgO, CaCO3, and Y2O3 in a molar percentage of 94%:2%:2%:2%. Mix deionized water and dispersant BYK in a volume ratio of 11:1 to obtain a solution. Mix the hollow SiO2 powder and the solution in a mass ratio of 1:1.5, ultrasonically disperse for 1 h, ball mill for 24 h at a rotation speed of 250 r / min, and then dry to obtain ceramic powder.
[0053] (2) Add PVA accounting for 5 wt% of the mass of the ceramic powder obtained in step (1), then granulate, screen, and mold to obtain a ceramic blank with a diameter of 12 mm and a thickness of 2 mm. The ceramic blank is heated at a rate of 2 °C / min to 550 °C for degumming for 5 h, then heated at a rate of 2 °C / min to 850 °C and held for 1 h, and then heated to 1000 °C at a rate of 2 °C and held for 2 h. Cool to room temperature at a cooling rate of 2 °C / min. Obtain a silicon-based hollow nano-ceramic matrix with ultra-low dielectric constant, low crystallization temperature, near-zero thermal expansion coefficient, and high anti-reduction property.
[0054] Comparative Example 1
[0055] A preparation method of a hollow SiO2 ceramic material, and its specific steps are as follows:
[0056] Add a PVA binder with a mass ratio of 30% to pure hollow SiO2 powder, granulate and mold to obtain a ceramic blank with a diameter of 12 mm and a thickness of 2 mm. The ceramic blank is heated in air at a heating rate of 2 °C / min to 550 °C for heat preservation and degumming for 2 h, heated at a rate of 2 °C / min to 850 °C and held for 1 h, and then heated to 1000 °C at a rate of 2 °C and held for 2 h. Obtain a SiO2 ceramic matrix material at a cooling rate of 2 °C / min.
[0057] Table 1 Performance test results of the hollow SiO2 ceramic matrix obtained in the examples and comparative examples
[0058]
[0059] As can be seen from Table 1, Examples 1 to 7 all meet the requirements of ultra-low dielectric constant, near-zero temperature coefficient of resonant frequency, relatively low crystallization temperature, with dielectric constants ranging from 2.1 to 2.9 and near-zero temperature coefficient of resonant frequency. The losses are all less than 0.1%. Among them, the preferred Example 7, after sintering at 1000 °C, completely transforms from the amorphous state to the crystalline state, with a significantly reduced transformation temperature of the amorphous state. At the same time, it maintains a low sintering volume shrinkage rate, maintains its hollow structure, has a dielectric constant of 2.16, a temperature coefficient of resonant frequency of 1.14 ppm / °C, and has good anti-reduction properties. Compared with Comparative Example 1, Examples 1 to 7 form a stable hollow structure, have high temperature stability and good anti-reduction properties, and can be used as ultra-low dielectric microwave dielectric materials for heterogeneous sintering; Examples 4 to 7 have fewer cracks than the ceramic materials of Examples 1 to 3, and by adjusting the doping materials and component content parameters, ceramic materials with higher temperature stability are obtained.
[0060] Figure 1 XRD patterns of Examples 1-8 and Comparative Example 1 are shown. As can be seen from the figure, Example 7 has the lowest amorphous-to-crystalline transformation temperature, significantly lower than that of Comparative Example 1.
[0061] Figure 2 SEM image of Example 7 is shown. As can be seen from the figure, it has high densification, and the grains do not grow abnormally during the sintering process due to the coating of the dopant, and its hollow structure is retained.
[0062] The present invention uses amorphous hollow SiO2 powder (particle size of 50-100 nm) as the matrix, and then adds MgO, CaCO3 and Y2O3 with a particle size of 10-30 nm as dopants. By using a method combining ultrasonic dispersion with a dispersant BYK and ball milling, the dopants are uniformly coated on the surface of the nano-hollow SiO2. Compared with the chemical coating method, this method has low cost and simple process, mainly due to:
[0063] (1) MgO can first form a coating layer on the hollow SiO2 at low temperature, inhibiting the penetration of the dopant with faster diffusion, thereby forming a preliminary "shell" structure on the surface of the hollow SiO2, which has the effect of refining grains and preventing excessive crystal growth, and forming a framework to support the hollow structure of the hollow SiO2 to reduce collapse during the sintering process.
[0064] (2) CaCO3 plays a role in refining grains, forming a liquid phase to promote sintering and dispersing the shrinkage stress. As a mineralizer, it provides heterogeneous nucleation sites, significantly reducing the crystallization temperature of the hollow SiO2, and at the same time can perform acceptor compensation to enhance the anti-reduction properties of the hollow SiO2 nano-matrix.
[0065] (3) Y2O3 plays a mineralizing role, provides nucleation sites, offers skeletal support, maintains the hollow structure of SiO2, and inhibits grain growth. It can simultaneously perform donor and acceptor compensation to enhance the anti-reduction property of the hollow SiO2 nano matrix.
[0066] (4) The method combining ultrasonic dispersion and low-speed ball milling with the dispersant BYK can uniformly coat 10 - 30 nm of MgO, CaCO3, and Y2O3 on the surface of hollow SiO2. The method is simple and can be used for large-scale production.
[0067] These four aspects ensure that the 50 - 100 nm amorphous hollow SiO2 matrix can form a uniform "core-shell" structure with 10 - 30 nm dopants before sintering, ensuring that it can maintain characteristics such as a hollow structure, low crystallization temperature, high temperature stability, and high anti-reduction property after sintering, inhibiting grain growth during the sintering process, and thus obtaining a hollow SiO2 nano ceramic material with an ultra-low dielectric constant (<200 nm) that can be mass-produced and is suitable for miniaturized, high-frequency LTCC filters.
[0068] (9) It is easy for those skilled in the art to understand that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.
Claims
1. A hollow SiO2-based dielectric ceramic material with improved dielectric constant, characterized in that: It includes a main material and a doping material; the main material is hollow amorphous SiO2, and the doping material includes one or more of MgO, CaCO3, and Y2O3; the ceramic material has a core-shell structure with the main material as the core layer and the doping material as the shell layer.
2. A hollow SiO2-based dielectric ceramic material with improved dielectric constant as claimed in claim 1, characterized in that: The molar percentages of the MgO, CaCO3, Y2O3 and the hollow amorphous SiO2 are (0-2.2%): (0-2.2%): (0-2.2%): (93.4%-97.8%), and the molar percentages of the MgO, CaCO3 and Y2O3 are not 0 at the same time.
3. A hollow SiO2-based dielectric ceramic material with improved dielectric constant as claimed in claim 1, characterized in that: The particle size of the hollow amorphous SiO2 is 50-100 nm, and the wall thickness is 6-16 nm; the particle sizes of the MgO, CaCO3 and Y2O3 are independently selected from 10-30 nm.
4. A method for preparing a hollow SiO2-based dielectric ceramic material with improved dielectric constant as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: (1) mixing a main material and a doping material, adding deionized water and a dispersant, and then sequentially performing ultrasonication, ball milling, and drying to obtain a ceramic powder; the main material is hollow amorphous SiO2, and the doping material includes one or more of MgO, CaCO3, and Y2O3; (2) The ceramic powder and the binder are mixed, and then granulated, sieved, and pressed in sequence to obtain a ceramic body; the ceramic body is first debinded and then sintered to obtain the hollow SiO2-based dielectric ceramic material.
5. The method for preparing a hollow SiO2-based dielectric ceramic material with improved dielectric constant as claimed in claim 4, characterized in that: The molar percentages of the MgO, CaCO3, Y2O3 and the hollow amorphous SiO2 are (0-2.2%): (0-2.2%): (0-2.2%): (93.4%-97.8%), and the molar percentages of the MgO, CaCO3 and Y2O3 are not 0 at the same time.
6. The method for preparing a hollow SiO2-based dielectric ceramic material with improved dielectric constant as claimed in claim 4, characterized in that: The volume ratio of the deionized water to the dispersant is (8-15):1, preferably (10-12):1; the mass ratio of the hollow amorphous SiO2 to the deionized water is 1:(1-3); the dispersant is selected from polymerized phosphate.
7. The method for preparing a hollow SiO2-based dielectric ceramic material with improved dielectric constant as claimed in claim 4, characterized in that: The binder is polyvinyl alcohol or polyvinyl butyral; the mass of the binder is 5% to 40% of the mass of the ceramic powder.
8. The method for preparing a hollow SiO2-based dielectric ceramic material with improved dielectric constant as claimed in claim 4, characterized in that: The debinding temperature is 500-600° C., and the debinding heat preservation time is 3-6 hours.
9. The method for preparing a hollow SiO2-based dielectric ceramic material with improved dielectric constant as claimed in claim 4, characterized in that: The sintering is firstly heated to 800-900°C and then kept warm for 0.5-2h, then heated to 950-1100°C and kept warm for 1-3h, and finally cooled to room temperature.
10. Use of a hollow SiO2-based dielectric ceramic material with improved dielectric constant according to any one of claims 1 to 3, characterized in that: The invention is used as a substrate, a filter or an antenna in the radio frequency field of the fifth generation mobile communication technology or the sixth generation mobile communication technology.