A low dielectric constant microwave dielectric ceramic material and its preparation method and application

Abstract

The present invention relates to a low dielectric constant microwave dielectric ceramic material and its preparation method and application. The expression of the low dielectric constant microwave dielectric ceramic material is: (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2, where 0≤q≤0.05, 0.9≤x≤1.1, 1.0≤y≤1.2, and 1.0≤z≤1.2. The low-dielectric-constant microwave dielectric ceramic material of the present invention can be sintered into porcelain within a range of 1000°C to 1200°C, has a relatively low sintering temperature and a wide sintering range, and has LaBSiO5 as the main crystal phase. It has the characteristics of a low dielectric constant, a high quality factor, and a near-zero resonant frequency temperature coefficient, meeting practical application requirements.

Description

Technical Field

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

[0002] As communication technology gradually develops towards microwave and millimeter waves, RF circuits have increasingly higher requirements for the microwave dielectric properties of dielectric materials. In particular, as substrate materials, the dielectric constant is required to be ≤8 (10GHz) to meet the high transmission rate of RF signals; the dielectric loss is required to be ≤0.002 (10GHz) to meet the low transmission loss of RF signals; and the resonant frequency temperature coefficient is required to be ≤±10ppm / ℃ to meet the high temperature stability of RF circuit systems.

[0003] At present, the research on low dielectric constant microwave dielectric ceramics mainly focuses on Al2O3, Mg2SiO4, and AWO4 systems. These materials have high sintering temperatures (>1400℃) and a narrow sintering range. They cannot simultaneously possess the three characteristics of low dielectric constant, high quality factor, and near-zero resonant frequency temperature coefficient. However, in practical applications, the materials must meet the requirements of low dielectric constant, high quality factor, and near-zero resonant frequency temperature coefficient, which limits their application in microwave RF circuit components. Summary of the Invention

[0004] Based on this, the current research on low dielectric constant microwave dielectric ceramics is mainly concentrated on Al2O3, Mg2SiO4, and AWO4 systems. These materials have high sintering temperatures (>1400°C) and a narrow sintering range. It is difficult to unify the low dielectric constant, high quality factor, and near-zero resonant frequency temperature coefficient, which limits their application in microwave RF circuit components. The purpose of the present invention is to provide a low dielectric constant microwave dielectric ceramic material and its preparation method and application. The low dielectric constant microwave dielectric ceramic material has a low dielectric constant, a high quality factor, and a near-zero resonant frequency temperature coefficient, which meets actual application needs.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a low dielectric constant microwave dielectric ceramic material, the expression of which is: (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2, where 0≤q≤0.05, 0.9≤x≤1.1, 1.0≤y≤1.2, 1.0≤z≤1.2.

[0007] The present invention proposes a low dielectric constant microwave dielectric ceramic material, which is a new type of lanthanum borosilicate system microwave dielectric ceramic. The sintering temperature of the ceramic is controlled by regulating the ratio of La2O3 and B2O3 in the ceramic system, so that the ceramic can be sintered into porcelain in the range of 1000°C to 1200°C. It has a low sintering temperature and a wide sintering range, and LaBSiO5 is the main crystal phase, ensuring that the system has the characteristics of low dielectric and low loss. By regulating the ratio of SiO2 in the ceramic system, the lattice distortion and atomic stacking density of the LaBSiO5 crystal phase are regulated, thereby regulating the dielectric constant of the control system. By incorporating TiO2, a positive temperature coefficient microwave dielectric ceramic material, the resonant frequency temperature coefficient of the material system can be effectively controlled, so that its resonant frequency temperature coefficient is within ±15ppm / °C.

[0008] As a further improvement of the above solution of the present invention, the main crystal phase of the low dielectric constant microwave dielectric ceramic material is La x B y Si z O (1.5x+1.5y+2z) , the secondary crystalline phase is TiO2.

[0009] As a further improvement of the above solution of the present invention, the La x B y Si z O (1.5x+1.5y+2z) The raw materials are La2O3, H3BO3, and SiO2.

[0010] As a further improvement of the above-mentioned solution of the present invention, the sintering temperature of the low dielectric constant microwave dielectric ceramic material is 1000℃~1200℃, the dielectric constant is 5.7~7.9, the Qf value is 26800GHz~49400GHz, and the resonant frequency temperature coefficient is -15~15ppm / ℃.

[0011] The present invention proposes a method for preparing the aforementioned low dielectric constant microwave dielectric ceramic material, comprising the following steps:

[0012] S1. Synthesis of La x B y Si z O (1.5x+1.5y+2z) Powder: La2O3, H3BO3, SiO2 powder as raw materials, according to the chemical formula La x B y Si z O (1.5x+1.5y+2z) The ingredients are mixed, ball-milled by wet mixing, dried, and calcined to obtain La x B y Si z O (1.5x+1.5y+2z) powder;

[0013] S2. Composite powder configuration: the La x B y Si z O (1.5x+1.5y+2z) Powder and TiO2 powder according to the chemical composition expression (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2 to prepare the ingredients to obtain composite powder;

[0014] S3 ball milling: ball milling the composite powder to obtain a ball-milled powder;

[0015] S4. Sintering: granulating the ball-milled powder, pressing the green body into a green body, and sintering the green body to obtain a low dielectric constant microwave dielectric ceramic material.

[0016] As a further improvement of the above solution of the present invention, in step S1, the wet mixing ball milling method is: placing the raw materials, ball milling balls, and deionized water in a ball mill at a mass ratio of 1:2:2 and wet ball milling for 10 to 15 hours.

[0017] As a further improvement of the above solution of the present invention, in step S1, the calcination is carried out at 900° C. to 100° C. for 1 to 4 hours.

[0018] As a further improvement of the above scheme of the present invention, in step S3, the ball milling method is: placing the composite powder, ball milling balls, and deionized water in a ball mill at a mass ratio of 1:2:2 for wet ball milling for 4 to 6 hours, and the ball milling speed is 350 to 400 r / min.

[0019] As a further improvement of the above solution of the present invention, in step S4, the granulation is performed by drying the ball-milled powder and mixing it with a 5 wt % PVA solution for granulation.

[0020] As a further improvement of the above solution of the present invention, in step S4, the green body is a cylindrical green body with a diameter of 10 mm and a height of 7 to 8 mm;

[0021] And / or, in step S4, the sintering is carried out at 1000° C. to 1200° C. for 30-60 minutes.

[0022] The present invention proposes an application of the low dielectric constant microwave dielectric ceramic material as described above in microwave radio frequency circuit components.

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

[0024] 1. The low dielectric constant microwave dielectric ceramic material proposed in the present invention is a new type of microwave dielectric ceramic in the lanthanum borosilicate system. By regulating the ratio of La2O3 and B2O3 in the ceramic system to control the ceramic's sintering temperature, the ceramic can be sintered into porcelain in the range of 1000°C to 1200°C. It has a low sintering temperature and a wide sintering range. LaBSiO5 is the main crystal phase, ensuring that the system has the characteristics of low dielectric and low loss.

[0025] 2. The present invention regulates the dielectric constant of the system by regulating the proportion of SiO2 in the ceramic system, regulating the lattice distortion and atomic packing density of the LaBSiO5 crystal phase.

[0026] 3. The present invention can effectively regulate the resonant frequency temperature coefficient of the material system by incorporating TiO2, a positive temperature coefficient microwave dielectric ceramic material, so that its resonant frequency temperature coefficient is within ±15ppm / °C.

[0027] 4. (1-q)La prepared by the present invention x B y Si z O (1.5x+1.5y+2z) The dielectric constant of +qTiO2 ceramic material is 5.7~7.9, the Qf value is 26800GHz~49400GHz, and the resonant frequency temperature coefficient is within ±15ppm / ℃. It is a new type of low-dielectric microwave dielectric ceramic material with low dielectric constant, high quality factor and near-zero resonant frequency temperature coefficient, which meets actual application needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a SEM image of the low dielectric constant microwave dielectric ceramic material prepared in Example 1 of the present invention;

[0029] Figure 2 This is an SEM image of the low dielectric constant microwave dielectric ceramic material prepared in Example 2 of the present invention;

[0030] Figure 3 This is an SEM image of the low dielectric constant microwave dielectric ceramic material prepared in Example 3 of the present invention;

[0031] Figure 4 This is the XRD pattern of the low dielectric constant microwave dielectric ceramic material prepared in Example 3 of the present invention;

[0032] Figure 5 This is an SEM image of the low dielectric constant microwave dielectric ceramic material prepared in Example 4 of the present invention. DETAILED DESCRIPTION

[0033] To facilitate understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0035] Example 1

[0036] This embodiment provides a low dielectric constant microwave dielectric ceramic material, which is expressed as (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2, wherein: q = 0.03, x = 0.9, y = 1.0, z = 1.0, and its preparation method comprises the following steps:

[0037] S1. Synthesis of La x B y Si z O (1.5x+1.5y+2z) Powder: La2O3, H3BO3, SiO2 powder as raw materials, according to the chemical formula La x B y Si z O (1.5x+1.5y+2z) The raw materials, ball milling balls and deionized water were placed in a ball mill at a mass ratio of 1:2:2 and wet milled for 12 hours. The mixture was then dried at 120°C for 24 hours and calcined at 1000°C for 3 hours to obtain La x B y Si z O (1.5x+1.5y+2z) powder;

[0038] S2. Composite powder configuration: La x B y Si z O (1.5x+1.5y+2z) Powder and TiO2 powder according to the chemical composition expression (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2 to prepare the ingredients to obtain composite powder;

[0039] S3 ball milling: The composite powder, ball milling balls, and deionized water were placed in a planetary ball mill at a mass ratio of 1:2:2 for 6 h at a ball milling speed of 400 r / min to obtain a ball-milled powder;

[0040] S4. Sintering: After drying the ball-milled powder, granulate it with a 5 wt% PVA solution and press it into a cylindrical green body with a diameter of 10 mm and a height of 7 to 8 mm. The cylindrical green body is sintered at a temperature of 1200°C for 30 minutes to obtain a low dielectric constant microwave dielectric ceramic material.

[0041] Figure 1 The SEM image of the low dielectric constant microwave dielectric ceramic material of this embodiment is shown in FIG. Figure 1 It can be seen from the figure that the ceramic of this embodiment is sintered more densely, the grains are evenly distributed, the average grain size is about 1 to 2 μm, and the ceramic forming properties are good.

[0042] The low dielectric constant microwave dielectric ceramic material prepared in this embodiment has a dielectric constant of 7.9, a Qf of 26800 GHz, and a resonant frequency temperature coefficient of -12.3 ppm / °C. It has the characteristics of low dielectric constant, high quality factor, and near-zero resonant frequency temperature coefficient, meeting actual application requirements.

[0043] Example 2

[0044] This embodiment provides a low dielectric constant microwave dielectric ceramic material, which is expressed as (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2, wherein: q = 0.03, x = 1.0, y = 1.0, z = 1.0, and its preparation method comprises the following steps:

[0045] S1. Synthesis of La x B y Si z O (1.5x+1.5y+2z) Powder: La2O3, H3BO3, SiO2 powder as raw materials, according to the chemical formula La x B y Si z O (1.5x+1.5y+2z) The raw materials, ball milling balls and deionized water were placed in a ball mill at a mass ratio of 1:2:2 and wet milled for 12 hours. The mixture was then dried at 120°C for 24 hours and calcined at 900°C for 3 hours to obtain La x B y Si z O (1.5x+1.5y+2z) powder;

[0046] S2. Composite powder configuration: La x By Si z O (1.5x+1.5y+2z) Powder and TiO2 powder according to the chemical composition expression (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2 to prepare the ingredients to obtain composite powder;

[0047] S3 ball milling: The composite powder, ball milling balls, and deionized water were placed in a planetary ball mill at a mass ratio of 1:2:2 for 6 h at a ball milling speed of 400 r / min to obtain a ball-milled powder;

[0048] S4. Sintering: After drying the ball-milled powder, granulate it with a 5 wt% PVA solution and press it into a cylindrical green body with a diameter of 10 mm and a height of 7 to 8 mm. The cylindrical green body is sintered at a temperature of 1150°C for 30 minutes to obtain a low dielectric constant microwave dielectric ceramic material.

[0049] Figure 2 The SEM images of the low dielectric constant microwave dielectric ceramic material of this embodiment are as follows: Figure 2 It can be seen that the ceramic of this embodiment is sintered more densely, with uniform grain distribution, an average grain size of about 2 to 3 μm, and no obvious pores, indicating that the ceramic can be sintered into porcelain at a temperature of 1150° C. and has good ceramic properties.

[0050] The low dielectric constant microwave dielectric ceramic material prepared in this embodiment has a dielectric constant of 6.5, a Qf of 32800 GHz, and a resonant frequency temperature coefficient of -11.1 ppm / °C. It has the characteristics of low dielectric constant, high quality factor, and near-zero resonant frequency temperature coefficient, meeting actual application requirements.

[0051] Example 3

[0052] This embodiment provides a low dielectric constant microwave dielectric ceramic material, which is expressed as (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2, wherein: q = 0.04, x = 1.0, y = 1.1, z = 1.1, and its preparation method comprises the following steps:

[0053] S1. Synthesis of La x B y Si z O (1.5x+1.5y+2z) Powder: La2O3, H3BO3, SiO2 powder as raw materials, according to the chemical formula La x B y Si z O (1.5x+1.5y+2z)The raw materials, ball milling balls and deionized water were placed in a ball mill at a mass ratio of 1:2:2 and wet ball milled for 12 hours. The mixture was then dried at 120°C for 24 hours and calcined at 900°C for 3 hours to obtain La x B y Si z O (1.5x+1.5y+2z) powder;

[0054] S2. Composite powder configuration: La x B y Si z O (1.5x+1.5y+2z) Powder and TiO2 powder according to the chemical composition expression (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2 to prepare the ingredients to obtain composite powder;

[0055] S3 ball milling: The composite powder, ball milling balls, and deionized water were placed in a planetary ball mill in a mass ratio of 1:2:2 for 6 hours at a ball milling speed of 400 r / min to obtain a ball-milled powder;

[0056] S4. Sintering: After drying the ball-milled powder, granulate it with a 5 wt% PVA solution and press it into a cylindrical green body with a diameter of 10 mm and a height of 7 to 8 mm. The cylindrical green body is sintered at a temperature of 1200°C for 30 minutes to obtain a low dielectric constant microwave dielectric ceramic material.

[0057] Figure 3 The SEM images of the low dielectric constant microwave dielectric ceramic material of this embodiment are as follows: Figure 3 It can be seen that the ceramics sintered at 1200℃ have better density, lower porosity, uniform grain growth and better porcelain forming properties.

[0058] Figure 4 The XRD patterns of the low dielectric constant microwave dielectric ceramic materials of this embodiment are as follows: Figure 4 It can be seen that the main crystalline phase of the ceramic is LaBSiO5 phase (JCPDS:#87-0965), and a small amount of second phase is generated.

[0059] The low dielectric constant microwave dielectric ceramic material prepared in this embodiment has a dielectric constant of 6.3, a Qf of 49400 GHz, and a resonant frequency temperature coefficient of -9.7 ppm / °C. It has the characteristics of low dielectric constant, high quality factor, and near-zero resonant frequency temperature coefficient, meeting actual application requirements.

[0060] Example 4

[0061] This embodiment provides a low dielectric constant microwave dielectric ceramic material, which is expressed as (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2, wherein: q = 0.05, x = 1.1, y = 1.2, z = 1.2, and its preparation method comprises the following steps:

[0062] S1. Synthesis of La x B y Si z O (1.5x+1.5y+2z) Powder: La2O3, H3BO3, SiO2 powder as raw materials, according to the chemical formula La x B y Si z O (1.5x+1.5y+2z) The raw materials, ball milling balls and deionized water were placed in a ball mill at a mass ratio of 1:2:2 and wet ball milled for 12 hours. The mixture was then dried at 120°C for 24 hours and calcined at 900°C for 3 hours to obtain La x B y Si z O (1.5x+1.5y+2z) powder;

[0063] S2. Composite powder configuration: La x B y Si z O (1.5x+1.5y+2z) Powder and TiO2 powder according to the chemical composition expression (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2 to prepare the ingredients to obtain composite powder;

[0064] S3 ball milling: The composite powder, ball milling balls, and deionized water were placed in a planetary ball mill in a mass ratio of 1:2:2 for 6 hours at a ball milling speed of 400 r / min to obtain a ball-milled powder;

[0065] S4. Sintering: After drying the ball-milled powder, granulate it with a 5 wt% PVA solution and press it into a cylindrical green body with a diameter of 10 mm and a height of 7 to 8 mm. The cylindrical green body is sintered at 1100°C for 30 minutes to obtain a low dielectric constant microwave dielectric ceramic material.

[0066] Figure 5 The SEM images of the low dielectric constant microwave dielectric ceramic material of this embodiment are as follows: Figure 5 It can be seen from the figure that the composite ceramics sintered at 1100℃ are denser and have better ceramic properties.

[0067] The low dielectric constant microwave dielectric ceramic material prepared in this embodiment has a dielectric constant of 5.9, a Qf of 42800 GHz, and a resonant frequency temperature coefficient of -8.4 ppm / °C. It has the characteristics of low dielectric constant, high quality factor, and near-zero resonant frequency temperature coefficient, meeting actual application requirements.

[0068] Comparative Example 1:

[0069] This comparative example provides a low dielectric constant microwave dielectric ceramic material, the expression of which is La x B y Si z O (1.5x+1.5y+2z) , wherein: x=1.0, y=1.1, z=1.1, and the preparation method comprises the following steps:

[0070] S1. Synthesis of La x B y Si z O (1.5x+1.5y+2z) Powder: La2O3, H3BO3, SiO2 powder as raw materials, according to the chemical formula La x B y Si z O (1.5x+1.5y+2z) The raw materials, ball milling balls and deionized water were placed in a ball mill at a mass ratio of 1:2:2 and wet milled for 12 hours. The mixture was then dried at 120°C for 24 hours and calcined at 900°C for 3 hours to obtain La x B y Si z O (1.5x+1.5y+2z) powder;

[0071] S2. Ball milling: The composite powder, ball milling balls, and deionized water were placed in a planetary ball mill at a mass ratio of 1:2:2 for 6 h at a ball milling speed of 400 r / min to obtain a ball-milled powder;

[0072] S3. Sintering: After drying the ball-milled powder, granulate it with a 5 wt% PVA solution and press it into a cylindrical green body with a diameter of 10 mm and a height of 7 to 8 mm. The cylindrical green body is sintered at a temperature of 1200°C for 30 minutes to obtain a low dielectric constant microwave dielectric ceramic material.

[0073] The low dielectric constant microwave dielectric ceramic material prepared in this comparative example has a dielectric constant of 5.5, a Qf of 55200 GHz, and a resonant frequency temperature coefficient of -48.5 ppm / °C, which cannot meet the near-zero characteristic.

[0074] Comparative Example 2:

[0075] This comparative example provides a low dielectric constant microwave dielectric ceramic material, the expression of which is (1-M)Lax B y Si z O (1.5x+1.5y+2z) +M CaTiO3, wherein: M = 0.08, x = 1.0, y = 1.13, z = 1.15, and its preparation method comprises the following steps:

[0076] S1. Synthesis of La x B y Si z O (1.5x+1.5y+2z) Powder: La2O3, H3BO3, SiO2 powder as raw materials, according to the chemical formula La x B y Si z O (1.5x+1.5y+2z) The raw materials, ball milling balls and deionized water were placed in a ball mill at a mass ratio of 1:2:2 and wet milled for 12 hours. The mixture was then dried at 120°C for 24 hours and calcined at 900°C for 3 hours to obtain La x B y Si z O (1.5x+1.5y+2z) powder;

[0077] S2. Synthesis of CaTiO3 powder: Using CaCO3 and TiO2 powder as raw materials, the ingredients are prepared according to the chemical formula CaCO3:TiO2=1:1. The raw materials, ball milling balls, and deionized water are placed in a ball mill at a mass ratio of 1:2:2 and wet ball milled for 12 hours. The mixture is then kept at 120°C for 24 hours and dried. The mixture is then calcined at 1400°C for 3 hours to obtain CaTiO3 powder.

[0078] S3. Composite powder configuration: La x B y Si z O (1.5x+1.5y+2z) Powder and CaTiO3 powder according to the chemical composition expression (1-M)La x B y Si z O (1.5x+1.5y+2z) +M CaTiO3 to prepare the ingredients to obtain composite powder;

[0079] S4. Ball milling: The composite powder, ball milling balls, and deionized water were placed in a planetary ball mill at a mass ratio of 1:2:2 for 6 h at a ball milling speed of 400 r / min to obtain a ball-milled powder;

[0080] S5. Sintering: After drying the ball-milled powder, granulate it with a 5 wt% PVA solution and press it into a cylindrical green body with a diameter of 10 mm and a height of 7-8 mm. The cylindrical green body is sintered at a temperature of 1200°C for 30 minutes to obtain a low dielectric constant microwave dielectric ceramic material.

[0081] The low-dielectric-constant microwave dielectric ceramic material produced in this comparative example has a dielectric constant of 6.8, a Qf of 12,200 GHz, and a resonant frequency temperature coefficient of 3.5 ppm / °C. By adding a CaTiO3 ceramic phase, the resonant frequency temperature coefficient can be adjusted to near zero, but the dielectric loss is significantly degraded, resulting in high losses that are unsuitable for practical applications.

[0082] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A low dielectric constant microwave dielectric ceramic material, characterized in that: Its expression is: (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2, where 0 <q≤0.05,0.9≤x≤1.1,1.0≤y≤1.2,1.0≤z≤1.2。 2. The low dielectric constant microwave dielectric ceramic material according to claim 1, characterized in that: The main crystal phase of the low dielectric constant microwave dielectric ceramic material is La x B y Si z O (1.5x+1.5y+2z) , the secondary crystalline phase is TiO2.

3. The low dielectric constant microwave dielectric ceramic material according to claim 1, characterized in that: The La x B y Si z O (1.5x+1.5y+2z) The raw materials are La2O3, H3BO3, and SiO2.

4. The low dielectric constant microwave dielectric ceramic material according to claim 1, characterized in that: The low dielectric constant microwave dielectric ceramic material has a sintering temperature of 1000° C. to 1200° C., a dielectric constant of 5.7 to 7.9, a Qf value of 26800 GHz to 49400 GHz, and a resonant frequency temperature coefficient of -15 to 15 ppm / ° C.

5. A method for preparing a low dielectric constant microwave dielectric ceramic material according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Synthesis of La x B y Si z O (1.5x+1.5y+2z) Powder: La2O3, H3BO3, SiO2 powder as raw materials, according to the chemical formula La x B y Si z O (1.5x+1.5y+2z) The ingredients are mixed, ball-milled by wet mixing, dried, and calcined to obtain La x B y Si z O (1.5x+1.5y+2z) powder; S2. Composite powder configuration: the La x B y Si z O (1.5x+1.5y+2z) Powder and TiO2 powder according to the chemical composition expression (1-q)La x B y Si z O (1.5x+1.5y+2z) +qTiO2 to prepare the ingredients to obtain composite powder; S3 ball milling: ball milling the composite powder to obtain a ball-milled powder; S4. Sintering: granulating the ball-milled powder, pressing the green body into a green body, and sintering the green body to obtain a low dielectric constant microwave dielectric ceramic material.

6. The method for preparing a low dielectric constant microwave dielectric ceramic material according to claim 5, characterized in that: In step S1, the wet mixing ball milling method is as follows: the raw materials, ball milling balls, and deionized water are placed in a ball mill at a mass ratio of 1:2:2 and wet ball milled for 10 to 15 hours; And / or, in step S1, the calcination is performed at 900° C. to 1000° C. for 1 to 4 hours.

7. The method for preparing a low dielectric constant microwave dielectric ceramic material according to claim 5, wherein: In step S3, the ball milling method is as follows: the composite powder, ball milling balls, and deionized water are placed in a ball mill at a mass ratio of 1:2:2 and wet ball milled for 4 to 6 hours at a ball milling speed of 350 to 400 r / min.

8. The method for preparing a low dielectric constant microwave dielectric ceramic material according to claim 5, characterized in that: In the step S4, the granulation is performed by drying the ball-milled powder and mixing it with a 5 wt % PVA solution for granulation.

9. The method for preparing a low dielectric constant microwave dielectric ceramic material according to claim 5, wherein: In step S4, the green body is a cylindrical green body with a diameter of 10 mm and a height of 7 to 8 mm; And / or, in step S4, the sintering is carried out at 1000° C. to 1200° C. for 30-60 minutes.

10. Use of the low dielectric constant microwave dielectric ceramic material according to any one of claims 1 to 4 in microwave radio frequency circuits and components.

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