Temperature stable low dielectric silicate ltcc material and method of making same
The low dielectric silicate LTCC material prepared by using xNa2O-yCaO-zSiO2-mCaSnSiO5-nB2O3 compound solves the problems of insufficient temperature stability and dielectric properties in the prior art, realizing low-temperature sintering and high-performance LTCC material, which is suitable for millimeter wave and terahertz communication.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WUHAN TEXTILE UNIV
- Filing Date
- 2026-04-10
- Publication Date
- 2026-06-30
AI Technical Summary
Existing commercial LTCC materials suffer from poor temperature stability and deterioration of dielectric properties, making it difficult to meet the needs of millimeter-wave and terahertz communication fields.
Temperature-stable low-dielectric silicate LTCC materials were prepared by using compounds with the chemical formula xNa2O-yCaO-zSiO2-mCaSnSiO5-nB2O3 through wet ball milling and low-temperature sintering. The main crystalline phase was Na2Ca2Si3O9, avoiding the introduction of the glass phase.
The prepared low-dielectric silicate LTCC material has a low dielectric constant, excellent quality factor and near-zero temperature coefficient of resonant frequency, ensuring excellent stability and performance at low temperatures, making it suitable for large-scale production.
Smart Images
Figure CN122010544B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of low-dielectric microwave dielectric ceramics technology, and in particular to a temperature-stable low-dielectric silicate LTCC material and its preparation method. Background Technology
[0002] Low-temperature co-fired ceramics (LTCC) technology is a novel multilayer substrate fabrication technology developed in the mid-1980s. This technology features a low sintering temperature (below 950℃), allowing co-firing with metallic conductors such as silver and copper, which is beneficial for improving the performance of electronic devices. Simultaneously, its unique multilayer co-firing process significantly simplifies the fabrication process and improves component reliability. The emergence of LTCC technology has powerfully driven the rapid development of microwave components towards miniaturization, multifunctionality, high frequency, and high reliability. With the advent of the 5G communication era, the development of 5G technology has placed even more stringent requirements on LTCC materials used in electronic components; especially in the upcoming millimeter-wave and terahertz communication fields, the demand for ultra-low dielectric constant LTCC materials is particularly urgent.
[0003] Currently, commercially available LTCC materials mainly include glass-ceramic systems and "glass + ceramic" multiphase systems. Existing LTCC materials typically contain a large amount of amorphous glass phase. While the introduction of the glass phase can lower the sintering temperature to below 950℃, it significantly degrades the microwave dielectric properties of the material. Furthermore, existing commercially available LTCC materials generally suffer from poor temperature stability, making it difficult to meet the requirements of devices such as resonators and dielectric antennas, greatly hindering the further development of LTCC integrated modules.
[0004] Therefore, it is necessary to develop a low dielectric constant silicate LTCC material with excellent temperature stability, no glass phase, and low-temperature sintering capability, as well as its preparation method, to solve the above-mentioned problems existing in the prior art. Summary of the Invention
[0005] The purpose of this application is to provide a method for preparing temperature-stable low-dielectric silicate LTCC materials, wherein the sintering temperature of the low-dielectric silicate LTCC materials prepared by this method is below 950°C. o With its low dielectric constant, high quality factor, and near-zero temperature coefficient of resonant frequency, the development of this temperature-stable low-dielectric silicate LTCC material broadens the selection range of temperature-stable low-dielectric LTCC materials.
[0006] To achieve the above-mentioned objectives, this application provides a temperature-stable low-dielectric silicate LTCC material, wherein the temperature-stable low-dielectric silicate LTCC material adopts the chemical formula […]. x Na2O- y CaO-z SiO2- m CaSnSiO5- n The compound of B2O3 was prepared, wherein 0.8 ≤ x ≤1.2, 1.8≤ y ≤2.2, 2.9≤ z ≤3.3, 0.6≤ m ≤1.5, 0.03≤ n The chemical formula of the main crystal phase of the temperature-stable low dielectric silicate LTCC material is Na2Ca2Si3O9, and there is no glass phase in the phase composition.
[0007] Preferably, the dielectric constant of the temperature-stable low-dielectric silicate LTCC material is... ε r The quality factor is 5.0 to 8.0. Q × f The resonant frequency temperature coefficient τ ranges from 6200 GHz to 14300 GHz. f The range is from -2.1 ppm / °C to -14.6 ppm / °C.
[0008] Furthermore, the preparation method of the temperature-stable low-dielectric silicate LTCC material includes the following steps:
[0009] S1. Weigh out the raw materials Na2CO3, CaO, SiO2, and B2O3 according to their chemical formulas. x Na2O- y CaO- z SiO2- n B2O3 (0.8≤ x ≤1.2, 1.8≤ y ≤2.2, 2.9≤ z ≤3.3, 0.03≤ n The ingredients are prepared in a stoichiometric ratio of ≤0.1, mixed evenly, and then subjected to a first wet ball milling process. After drying and pre-firing, pre-fired ceramic powder is obtained.
[0010] S2. Weigh CaO, SnO2 and SiO2 as raw materials and mix them according to the stoichiometric ratio of CaSnSiO5. After mixing evenly, perform a second wet ball milling treatment, and then dry and pre-fire to obtain CaSnSiO5 pre-fired ceramic powder.
[0011] S3. Combine the pre-fired ceramic powder obtained in step S1 and the CaSnSiO5 pre-fired ceramic powder obtained in step S2, according to... x Na2O- y CaO- z SiO2- m CaSnSiO5-n B2O3 was mixed in stoichiometric proportions and subjected to a third wet ball milling process. After ball milling, the mixture was dried, and a binder was added to granulate the mixture. After pressing into tablets, the mixture was sintered to obtain low dielectric silicate LTCC material.
[0012] Preferably, in step S1, the pre-firing temperature is 700~850℃ and the pre-firing time is 5~10h.
[0013] Preferably, in step S2, the pre-firing temperature is 1050~1150℃ and the sintering time is 5~10h.
[0014] In step S3, the sintering temperature is 800~925℃ and the sintering time is 5~10h.
[0015] Preferably, in steps S1, S2 and S3, the dispersant for the first, second and third wet ball milling treatments is 300wt% anhydrous ethanol, the ball milling medium is zirconium balls, the ball milling speed is 360 r / min, and the ball milling time is 5~10 h.
[0016] Preferably, in step S3, the adhesive is PVA or paraffin.
[0017] Preferably, in step S3, the amount of adhesive added is 5-10% of the mass ratio of the pre-fired ceramic powder.
[0018] The beneficial effects of this application are:
[0019] The temperature-stable low-dielectric silicate LTCC material provided in this application has the chemical formula: x Na2O- y CaO- z SiO2- m CaSnSiO5- n B2O3 compounds are used to prepare temperature-stable low-dielectric silicate LTCC materials. The above method for preparing temperature-stable low-dielectric silicate LTCC materials overcomes the defect of poor temperature stability in the preparation of low-dielectric-constant LTCC materials at low sintering temperatures in the prior art. The obtained temperature-stable low-dielectric silicate LTCC materials have the characteristics of low sintering temperature, low dielectric constant, excellent quality factor and near-zero temperature coefficient of resonant frequency.
[0020] Low dielectric constant can reduce the interactive coupling loss between the material and the electrode and improve the transmission rate of electrical signals. Excellent quality factor can reduce system loss and improve the frequency selectivity of the material. The near-zero temperature coefficient of resonant frequency can ensure the temperature stability of LTCC devices during operation. Secondly, temperature-stable low dielectric silicate LTCC materials with Na2Ca2Si3O9 as the main crystalline phase have the advantages of stable main phase composition, good batch stability, low raw material price and suitability for large-scale production. They have comprehensive performance superior to existing commercial materials and are a material with great application prospects. Attached Figure Description
[0021] Figure 1 The products obtained in Examples 1-5 x Na2O- y CaO- z SiO2- m CaSnSiO5- n Sample image of B2O3 material;
[0022] Figure 2 The products obtained in Examples 1-5 x Na2O- y CaO- z SiO2- m CaSnSiO5- n XRD pattern of B2O3 material;
[0023] Figure 3 The product obtained in Example 2 x Na2O- y CaO- z SiO2- m CaSnSiO5- n SEM image of the surface of B2O3LTCC material.
[0024] Figure 4 The product obtained in Example 3 x Na2O- y CaO- z SiO2- m CaSnSiO5- n SEM image of the surface of B2O3LTCC material. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of this application clearer, the application will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0026] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the structures and / or processing steps closely related to the solution of this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.
[0027] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0028] This application provides the application of a compound in the preparation of LTCC materials, wherein the chemical formula of the compound is as follows: x Na2O- y CaO- z SiO2- m CaSnSiO5- n The compound of B2O3 was prepared, wherein 0.8 ≤ x ≤1.2, 1.8≤ y ≤2.2, 2.9≤ z ≤3.3, 0.6≤ m ≤1.5, 0.03≤ n The dielectric constant of the temperature-stable low-dielectric silicate LTCC material is ≤0.1. The chemical formula for the main crystalline phase is Na₂Ca₂Si₃O₉, and it contains no glassy phase. The dielectric constant of the LTCC material prepared using the above compound is... ε r The quality factor is 5.0 to 8.0. Q × f The resonant frequency temperature coefficient τ ranges from 6200 GHz to 14300 GHz. f The range is from -2.1 ppm / °C to -14.6 ppm / °C.
[0029] This application provides the application of the above chemical expression as... x Na2O- y CaO- z SiO2- m CaSnSiO5- n The specific preparation method for LTCC materials using B2O3 compounds is as follows:
[0030] S1. Weigh out the raw materials Na2CO3, CaO, SiO2, and B2O3 according to their chemical formulas. x Na2O- y CaO- z SiO2- nB2O3 (0.8≤ x ≤1.2, 1.8≤ y ≤2.2, 2.9≤ z ≤3.3, 0.03≤ n The ingredients are prepared in a stoichiometric ratio of ≤0.1, mixed evenly, and then subjected to a first wet ball milling process. After drying and pre-firing, pre-fired ceramic powder is obtained.
[0031] The pre-firing temperature is 700~850℃, and the pre-firing time is 5~10h.
[0032] S2. Weigh CaO, SnO2 and SiO2 as raw materials and mix them according to the stoichiometric ratio of CaSnSiO5. After mixing evenly, perform a second wet ball milling treatment, and then dry and pre-fire to obtain CaSnSiO5 pre-fired ceramic powder.
[0033] The pre-firing temperature is 1050~1150℃, and the sintering time is 5~10h.
[0034] S3. Combine the pre-fired ceramic powder obtained in step S1 and the CaSnSiO5 pre-fired ceramic powder obtained in step S2, according to... x Na2O- y CaO- z SiO2- m CaSnSiO5- n B2O3 was mixed in stoichiometric proportions and subjected to a third wet ball milling process. After ball milling, the mixture was dried, and a binder was added to granulate the mixture. After pressing into tablets, the mixture was sintered to obtain low dielectric silicate LTCC material.
[0035] The sintering temperature is 800~925℃, and the sintering time is 5~10h.
[0036] In steps S1, S2, and S3, the dispersant for the first, second, and third wet ball milling treatments is 300 wt% anhydrous ethanol, the ball milling medium is zirconium balls, the ball milling speed is 360 r / min, and the ball milling time is 5 to 10 h.
[0037] The adhesive is PVA or paraffin.
[0038] The amount of binder added is 5-10% of the mass of the pre-fired ceramic powder.
[0039] The preparation method of the ultra-low dielectric constant silicon-based microwave dielectric ceramic of this application will be further explained below with reference to specific embodiments:
[0040] Example 1
[0041] This embodiment prepares a temperature-stable low-dielectric silicate LTCC material. The specific preparation method is as follows:
[0042] S1. Take Na₂CO₃, CaO, SiO₂, and B₂O₃ with a purity of 99.9%, and arrange them according to the chemical formula... x Na2O- y CaO- z SiO2- n The ingredients are prepared according to the stoichiometric ratio of B2O3, wherein 0.8 ≤ x ≤1.2, 1.8≤ y ≤2.2, 2.9≤ z ≤3.3, 0.03≤ n ≤0.1; After mixing evenly, zirconium balls were used as the ball milling medium and anhydrous ethanol as the dispersant. The powder was mixed and stirred in a ball mill for 5 hours at a speed of 360 r / min for the first wet ball milling treatment. After drying the obtained slurry, it was pre-fired at 800℃ for 5 hours to obtain pre-fired ceramic powder.
[0043] S2. Weigh out raw materials of CaO, SnO2 and SiO2 with a purity of 99.9% and mix them according to the stoichiometric ratio of CaSnSiO5. After mixing evenly, use zirconium balls as the ball milling medium and anhydrous ethanol as the dispersant to mix and stir the powder for 5 hours in a ball mill at a speed of 360 r / min for a second wet ball milling treatment. After drying the obtained slurry, pre-fire it at 1150℃ for 10 hours to obtain CaSnSiO5 pre-fired ceramic powder.
[0044] S3. Combine the pre-fired ceramic powder obtained in step S1 and the CaSnSiO5 pre-fired ceramic powder obtained in step S2, according to... x Na2O- y CaO- z SiO2- m CaSnSiO5- n B2O3 was stoichiometrically proportioned and subjected to a third wet ball milling process. After ball milling, the ceramic powder was dried to obtain ceramic powder. Polyvinyl alcohol (8% by mass) was then added to the ceramic powder as a binder for granulation. The powder was then pressed into cylindrical green samples with a thickness-to-diameter ratio of 0.4 to 0.6 under a pressure of 150 MPa. After pressing, the green samples were sintered in air at 800 to 925 °C for 5 hours to obtain silicon-based microwave dielectric ceramic.
[0045] The conditions for the third wet ball milling treatment were the same as those for the first and second wet ball milling treatments.
[0046] Example 2-11
[0047] The only difference between Examples 2-11 and Example 1 is that in the compounds... x, y, z, m, nThe values of and sintering temperatures are different, as shown in Table 1. Other steps are basically the same as in Example 1, and will not be repeated here.
[0048] Table 1. Performance comparison of silicon-based microwave dielectric ceramics prepared in Examples 1-11
[0049]
[0050] Figure 1 The images show the sintered samples of temperature-stable low-dielectric silicate LTCC materials prepared in Examples 1-5. It can be seen that the sintered samples exhibit good ceramic-forming properties.
[0051] Figure 2 The products obtained in Examples 1-5 x Na2O- y CaO- z SiO2- m CaSnSiO5- n XRD pattern of B2O3 material.
[0052] As can be seen, the main crystalline phase of the prepared low dielectric silicate LTCC material is Na2Ca2Si3O9, and there is no glass phase in the phase composition.
[0053] Figure 3 , Figure 4 The images show surface SEM images of the low dielectric silicate LTCC materials prepared in Examples 2 and 3, respectively.
[0054] As can be seen, the surface morphology of the sintered low dielectric silicate LTCC material is very dense.
[0055] Table 1 shows that the dielectric constant of the prepared low-dielectric silicate LTCC material is... ε r The quality factor is 5.0 to 8.0. Q × f The resonant frequency temperature coefficient τ ranges from 6200 GHz to 14300 GHz. f With a temperature range of -2.1 ppm / °C to -14.6 ppm / °C, it can be seen that this low dielectric silicate LTCC material has the characteristic of stable resonant frequency at temperature.
[0056] Low dielectric silicate LTCC materials with Na2Ca2Si3O9 as the main crystalline phase do not contain easily variable valence elements, are not prone to deliquescence, and have a low sintering temperature, thus they can be used as candidate materials for the preparation of dielectric components and for electronic packaging.
[0057] In summary, the temperature-stable low-dielectric silicate LTCC material proposed in this application has the chemical formula […]. x Na2O- y CaO-z SiO2- m CaSnSiO5- n B2O3 compounds are used to prepare silicon-based microwave dielectric ceramics. The resulting temperature-stable low-disilicate LTCC materials have the characteristics of low sintering temperature, low dielectric constant, excellent quality factor and excellent stability. They have comprehensive performance superior to existing commercial materials and are a material with great application prospects.
[0058] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.
Claims
1. A temperature-stable low-dielectric silicate LTCC material, characterized in that, The temperature-stable low-diisocyanate LTCC material uses the chemical formula […]. x Na2O- y CaO- z SiO2- m CaSnSiO5- n The compound of B2O3 was prepared, wherein 0.8 ≤ x ≤1.2, 1.8≤ y ≤2.2, 2.9≤ z ≤3.3, 0.6≤ m ≤1.5, 0.03≤ n The content is ≤0.1, and the chemical expression of the main crystal phase of the low dielectric silicate LTCC material is Na2Ca2Si3O9, and there is no glass phase in the phase composition.
2. The temperature-stable low-dielectric silicate LTCC material according to claim 1, characterized in that, The dielectric constant of the temperature-stable low-disilicate LTCC material ε r The quality factor is 5.0 to 8.
0. Q × f The resonant frequency temperature coefficient τ ranges from 6200 GHz to 14300 GHz. f The range is from -2.1 ppm / °C to -14.6 ppm / °C.
3. A method for preparing a temperature-stable low-dielectric silicate LTCC material as described in claim 1 or 2, characterized in that, Includes the following steps: S1. Weigh out the raw materials Na2CO3, CaO, SiO2, and B2O3 according to their chemical formulas. x Na2O- y CaO- z SiO2- n The ingredients are prepared according to the stoichiometric ratio of B2O3, wherein 0.8 ≤ x ≤1.2, 1.8≤ y ≤2.2, 2.9≤ z ≤3.3, 0.03≤ n ≤0.1; After being mixed evenly, the mixture undergoes a first wet ball milling process, followed by drying and pre-firing to obtain pre-fired ceramic powder; S2. Weigh CaO, SnO2 and SiO2 as raw materials and mix them according to the stoichiometric ratio of CaSnSiO5. After mixing evenly, perform a second wet ball milling treatment, and then dry and pre-fire to obtain CaSnSiO5 pre-fired ceramic powder. S3. Combine the pre-fired ceramic powder obtained in step S1 and the CaSnSiO5 pre-fired ceramic powder obtained in step S2, according to... x Na2O- y CaO- z SiO2- m CaSnSiO5- n B2O3 was mixed in stoichiometric proportions and subjected to a third wet ball milling process. After ball milling, the mixture was dried, and a binder was added for granulation. The granules were then pressed into tablets and sintered to obtain low dielectric silicate LTCC material.
4. The method for preparing low-dielectric silicate LTCC material according to claim 3, characterized in that, In step S1, the pre-firing temperature is 700~850℃ and the pre-firing time is 5~10h.
5. The method for preparing low-dielectric silicate LTCC material according to claim 3, characterized in that, In step S2, the pre-firing temperature is 1050~1150℃ and the pre-firing time is 5~10h.
6. The method for preparing low-dielectric silicate LTCC material according to claim 3, characterized in that, In step S3, the sintering temperature is 800~925℃ and the sintering time is 5~10h.
7. The method for preparing low-dielectric silicate LTCC material according to claim 3, characterized in that, In steps S1, S2, and S3, the dispersant used in the first, second, and third wet ball milling processes is anhydrous ethanol, the ball milling medium is zirconium balls, and the ball milling time is 5-10 hours.
8. The method for preparing low-dielectric silicate LTCC material according to claim 3, characterized in that, In step S3, the adhesive is PVA or paraffin.