CN110317057A

CN110317057A - A kind of medium dielectric constant low-temperature co-fired ceramic and preparation method

Info

Publication number: CN110317057A
Application number: CN201910372110.3A
Authority: CN
Inventors: 齐世顺; 程华容; 宋蓓蓓; 杨魁勇; 孙淑英
Original assignee: Beijing Yuan Six Hongyuan Electronic Polytron Technologies Inc
Current assignee: Beijing Yuan Six Hongyuan Electronic Polytron Technologies Inc
Priority date: 2019-05-06
Filing date: 2019-05-06
Publication date: 2019-10-11
Anticipated expiration: 2039-05-06
Also published as: CN110317057B

Abstract

The invention discloses a kind of medium dielectric constant low-temperature co-fired ceramic and preparation methods, wherein, ceramic material includes: the powder D of the Ba-Ti compound of 50~70 mass parts, the powders A of 0~5 mass parts, the powder B of 30~45 mass parts, the powder C of 2~15 mass parts and 0~2 mass parts；Wherein, Ba-Ti compound includes BaCO₃And TiO₂, powders A BaZn₂Ti₄O₁₁, powder B includes Ba (OH)₂、H₃BO₃, ZnO and La₂O₃, the group of powder C is divided into SrTiO₃、TiO₂And CaTiO₃One of or it is a variety of, powder D be MnO₂、Co₂O₃And Cr₂O₃One of or it is a variety of.According to the technical solution of the present invention, more excellent ceramic microwave characteristic is obtained, preparation process is simple, is suitble to large-scale production, and good with microwave matrix match materials, effectively reduces the sintering temperature of material.

Description

Medium-dielectric-constant low-temperature co-fired ceramic material and preparation method thereof

Technical Field

The invention relates to the technical field of ceramic materials, in particular to a medium-dielectric-constant low-temperature co-fired ceramic material and a preparation method thereof.

Background

The Low Temperature Co-fired ceramic (LTCC) technology is used as an electronic component integration technology, a multilayer wiring structure is adopted, the integration of passive elements (resistors, capacitors, inductors, filters, resonators and couplers) and transmission lines can be realized on a three-dimensional structure, IC elements can be surface-mounted, the high integration and functional composition of the components can be realized on the basis of keeping excellent high-frequency characteristics, and the requirements of future electronic equipment development can be met. The LTCC microwave passive component has the advantages of low dielectric loss, high working frequency (up to 40GHz), small volume and high stability in severe environment, and is widely applied to the fields of communication, automotive electronics, aerospace, consumer electronics, military control systems and the like. However, most of the existing LTCC devices are mainly developed based on LTCC materials with low dielectric constants, and the volume of the LTCC devices is relatively large, so that the requirements of miniaturization and light weight of the devices are difficult to meet. To realize integration and modularization of passive components, LTCC materials with various dielectric constants and excellent performance must be developed. Considerable work has been done in this area by foreign associates, and low dielectric constant LTCC materials have become relatively mature and have emerged from internationalized vendors such as Dupont, Ferro, Heraeus, etc. At present, many research reports are made in the aspect of localization of low dielectric constant LTCC materials in China. However, such low dielectric constant LTCC materials are not suitable for use in the fabrication of microwave devices such as multilayer dielectric resonators, microwave antennas, and filters. The size of the device is inversely proportional to the dielectric constant of the medium, and the high dielectric constant is beneficial to the miniaturization of the device, so that the development of the LTCC material with higher dielectric constant and higher quality factor has important significance for realizing the miniaturization of the LTCC component. At present, the mature LTCC materials with medium dielectric constant of manufacturers at home and abroad are relatively few, no mature products are sold, and most of researches are still in the research report stage of academic papers.

The development of a novel LTCC material with medium dielectric constant must ensure that the material has excellent quality factor and frequency temperature characteristic. The high quality factor can improve the frequency selection characteristic of the device, which is particularly important for high-frequency components; the low frequency temperature coefficient can ensure the stable performance of the device when working at different temperatures. BaO-TiO₂In-system BaTi₄O₉Ceramics and Ba₂Ti₉O₂₀The ceramic is two microwave dielectric ceramics which are most researched at present, BaTi₄O₉Microwave characteristics of ceramics,. epsilon_r＝37～40、Q×f＝22700–32000GHz、τ_f＝15ppm/℃；Ba₂Ti₉O₂₀The microwave characteristic of the ceramic is epsilon_r＝40、Q×f＝32000GHz、τ_f2 ppm/c. But the sintering temperature of both microwave materials exceeded 1300 c. Researchers have prepared BaZn by doping Zn into Ba-Ti material₂Ti₄O₁₁Ceramics having microwave properties of epsilon_r＝30、Q×f＝68000GHz、τ_f-30 ppm/c and the sintering temperature can be lowered to around 1200 c. However, the sintering temperature of the above materials is too high to co-sinter with high-frequency electrode materials such as Ag, Cu and Au, which greatly limits the application of the above materials in the field of microwave devices.

Generally, the method for lowering the sintering temperature of the ceramic material mainly comprises introducing a chemical synthesis method, preparing ultrafine powder, adding low-melting-point glass, a compound or an oxide as a sintering aid and the like. However, the chemical synthesis method and the use of the ultra-fine powder may result in a complicated process, and a manufacturing period and cost may be sharply increased. In comparison, the addition of low-melting-point glass, compound or oxide matched with the material matrix can reduce the microwave performance of the matrix material, but the process is simple and easy to realize industrial production. However, the low-melting glass has complex components and process, high production cost, long heat treatment time and large energy consumption, and needs professional equipment for high-temperature melting of the glass. In addition, the cold quenching process of the glass has large equipment loss, the quenched glass slag has high hardness, is difficult to mill, and has poor shape and process adaptability. Low-melting oxides, e.g. V₂O₅And B₂O₃Although the sintering temperature of the material can be effectively reduced, the material is very easy to have gel reaction with organic additives such as PVA, PVB and the like in the process, and the production of the ceramic casting film belt is influenced. Thus realizing BaO-TiO₂The key to the low-temperature sintering of the series materials is to develop a low-temperature sintering aid matched with a microwave medium ceramic matrix.

Disclosure of Invention

In order to solve at least one of the problems, the invention provides a medium-dielectric-constant low-temperature co-fired ceramic material and a preparation method thereof, a Ba-Ti material is used as a ceramic matrix material, excellent microwave characteristics are obtained by adjusting the relative proportion of Ba and Ti in the material, and BaZn is added into the material₂Ti₄O₁₁For adjusting the microstructure and tau of ceramic matrix materials_fIn addition, a low-sintering aid material system suitable for the matrix material is developed by adopting a solid-phase synthesis method, the preparation process is simple, the method is suitable for large-scale production, the matching property with the microwave matrix material is good, and the sintering temperature of the material is effectively reduced.

In order to achieve the above object, the present invention provides a low-temperature co-fired ceramic material with a medium dielectric constant, comprising: 50-70 parts by mass of a Ba-Ti compound, 0-5 parts by mass of a powder A, 30-45 parts by mass of a powder B, 2-15 parts by mass of a powder C and 0-2 parts by mass of a powder D; wherein the Ba-Ti compound comprises 30-50 parts by mass of BaCO₃And 50-70 parts by mass of TiO₂The powder A is BaZn₂Ti₄O₁₁The powder B comprises 20-45 parts by mass of Ba (OH)₂20-40 parts by mass of H₃BO₃25-50 parts by mass of ZnO and 0-5 parts by mass of La₂O₃The component of the powder C is SrTiO₃、TiO₂And CaTiO₃Wherein the powder D is MnO₂、Co₂O₃And Cr₂O₃One or more of (a).

In the above technical solution, preferably, the preparation of the Ba-Ti compound comprises: weighing 30-50 parts by mass of BaCO₃And 50-70 parts by mass of TiO₂Putting the prepared powder into a ball mill for mixing, wherein the ball/material mass ratio is 2-15, grinding balls are zirconia balls, the ball milling time is 4-8 hours, the rotating speed is 250-450 rpm, putting the ball-milled powder into an oven for drying at 120 ℃, and sieving the powder with a 100-mesh sieve after grinding; and (3) preserving the heat of the powder obtained after sieving at 1100-1200 ℃ for 2-6 hours, and grinding the calcined powder and sieving with a 100-mesh sieve to obtain the Ba-Ti compound.

In the above technical solution, preferably, the preparation of the powder a includes: according to BaZn₂Ti₄O₁₁Stoichiometric weighing of BaCO₃ZnO and TiO₂After being prepared, the powder is put into a ball mill for mixing, the ball/material mass ratio is 2-15, the grinding balls are zirconia balls, the ball milling time is 4-8 hours, the rotating speed is 250-450 r/min, the powder after ball milling is put into an oven for drying at 120 ℃, and the powder is ground and then passes through a 100-mesh sieve; and (3) preserving the heat of the sieved powder at 1100-1200 ℃ for 2-6 hours, and grinding the calcined powder and sieving the ground powder with a 100-mesh sieve to obtain powder A.

In the above technical solution, preferably, the preparation of the powder B includes: weighing 20-45 parts by mass of Ba (OH)₂20-40 parts by mass of H₃BO₃25-50 parts by mass of ZnO and 0-5 parts by mass of La₂O₃. After being prepared, the powder is put into a ball mill for mixing, the ball/material mass ratio is 2-15, the grinding balls are zirconia balls, the ball milling time is 4-8 hours, the rotating speed is 250-450 r/min, the powder after ball milling is put into an oven for drying at 80 ℃, and the powder is ground and then passes through a 100-mesh sieve; and (3) preserving the heat of the sieved powder at 600-700 ℃ for 2-6 hours, and grinding the calcined powder and sieving the ground powder with a 100-mesh sieve to obtain powder B.

The invention also provides a preparation method of the medium-dielectric-constant low-temperature co-fired ceramic material, which comprises the following steps: weighing 50-70 parts by mass of Ba-Ti compound, 0-5 parts by mass of powder A, 30-45 parts by mass of powder B and 2-15 parts by mass of powderPowder C and 0-2 parts by mass of powder D; wherein the powder C is SrTiO₃、TiO₂And CaTiO₃Wherein the powder D is MnO₂、Co₂O₃And Cr₂O₃One or more of; putting the weighed powder into a ball mill, drying after ball milling, and sieving after grinding; adding the sieved powder into a PVA aqueous solution for granulation, and preparing wafers and cylinders; and (3) removing the glue of the formed wafer and the cylinder, and sintering to obtain the ceramic wafer and the cylinder.

In the above technical solution, preferably, the method for preparing the low-temperature co-fired ceramic material with a medium dielectric constant specifically includes: weighing 50-70 parts by mass of Ba-Ti compound, 0-5 parts by mass of powder A, 30-45 parts by mass of powder B, 2-15 parts by mass of powder C and 0-2 parts by mass of powder D; wherein the powder C is SrTiO₃、TiO₂And CaTiO₃Wherein the powder D is MnO₂、Co₂O₃And Cr₂O₃One or more of; putting the prepared powder into a ball mill for mixing, wherein grinding balls are zirconia balls, the ball/material mass ratio is 2-15, the ball milling time is 4-8 hours, the rotating speed is 250-450 rpm, putting the ball-milled powder into an oven for drying at 120 ℃, and sieving the powder with a 100-mesh sieve after grinding; taking 1.5g of powder, adding 20-30 drops of 6.5 wt% PVA aqueous solution for granulation, and then preparing wafers and cylinders with the diameter of 10mm under the pressure of 250 MPa; and (3) putting the formed wafer and the cylinder into a sintering furnace, raising the temperature to 550 ℃ at the rate of 2 ℃/min, preserving the heat for 2 hours, discharging the glue from the blank, raising the temperature to 850-900 ℃ at the rate of 5 ℃/min, preserving the heat for 0.5-2 hours, sintering, and naturally cooling along with the furnace to obtain the ceramic wafer and the cylinder.

Compared with the prior art, the invention has the beneficial effects that: by adjusting the relative proportion of Ba and Ti in the Ba-Ti compound, a ceramic matrix material with excellent performance is obtained, and by adjusting the formula of the material, the material is sintered and densified at a lower temperature, the dielectric constant is continuously adjustable within the range of 18-35, and meanwhile, the temperature coefficient of the resonant frequency is small and stable, the Qxf value is high, the insulating property is excellent, and the microwave characteristic is excellent, so that the microwave material can be applied to the research, development and production of various LTCC radio frequency components. The Ba-Ti ceramic matrix material and the low-temperature sintering aid are both prepared by a solid-phase synthesis method, so that a preparation process of using a melting-cold quenching glass sintering aid is avoided, the process is simple, the Ba-Ti ceramic matrix material is suitable for large-scale production, the manufacturing cost is low, the Ba-Ti ceramic matrix material is well matched with a microwave matrix material, and the sintering temperature of the material is effectively reduced.

Drawings

FIG. 1 is a surface profile (a) and a cross-sectional profile (b) of a low-temperature co-fired ceramic material with a dielectric constant after sintering at 850 ℃ in example 20 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention and the accompanying drawings, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. The raw materials selected by the invention can be purchased through commercial channels if no special description is provided.

The invention is described in further detail below with reference to examples and figures:

according to the low-temperature co-fired ceramic material with the medium dielectric constant and the preparation method thereof, the dielectric constant is adjustable within the range of 18-35, the Qxf value is high, and the temperature coefficient tau of the resonant frequency is high_fSmall size and excellent insulating performance. The material consists of 50-70 parts by mass of Ba-Ti compound, 0-5 parts by mass of powder A, 30-45 parts by mass of powder B, 2-15 parts by mass of powder C and 0-2 parts by mass of powder D, wherein:

the Ba-Ti compound is a pre-sintered body and consists of 30-50 parts by mass of BaCO₃And 50-70 parts by mass of TiO₂And (4) forming. The powder A is a pre-sintered body, and the chemical component of the powder A is BaZn₂Ti₄O₁₁. The powder B is a pre-sintered body with the components of 20 to45 parts by mass of Ba (OH)₂20-40 parts by mass of H₃BO₃25-50 parts by mass of ZnO and 0-5 parts by mass of La₂O₃. The powder C is SrTiO₃、TiO₂And CaTiO₃One or more of (a). The powder D is MnO₂、Co₂O₃And Cr₂O₃One or more of (a).

Example (b):

the invention calculates the formula according to the mass parts, and uses the Ba-Ti compound synthesized by solid phase, the powder A, the powder B, the powder C and the analytically pure powder D, and the concrete examples are shown in the table 1. Wherein the Ba-Ti compound is a pre-sintered body composed of 30-50 parts by mass of BaCO₃And 50-70 parts by mass of TiO₂And (4) forming. The powder A is a pre-sintered body and the chemical component of the powder A is BaZn₂Ti₄O₁₁. The powder B is a pre-sintered body, and the components of the powder B are 20-45 parts by mass of Ba (OH)₂20-40 parts by mass of H₃BO₃25-50 parts by mass of ZnO and 0-5 parts by mass of La₂O₃. The powder C is SrTiO₃、TiO₂And CaTiO₃One or more of (a). The powder D is MnO₂、Co₂O₃And Cr₂O₃One or more of (a).

In Table 1, the synthesis temperature of the Ba-Ti compound was 1150 ℃ and BaCO was₃And TiO₂The relative mass fraction of (A) is shown in Table 1, other mass fractions and other synthesis temperatures can also meet the requirements, and are not described one by one herein; the synthesis temperature of the powder A is 1150 ℃, and the powder A obtained at other synthesis temperatures can meet the requirements and is not described one by one; the powder B is a pre-sintered body, the content and specific components of the powder B are shown in Table 1, other chemical compositions can also meet the requirements, and the requirements are not described one by one; powder C is SrTiO₃、TiO₂And CaTiO₃One or more of; powder D is MnO₂、Co₂O₃And Cr₂O₃One or more of (a).

TABLE 1 formulation of some examples of low temperature co-fired ceramic materials with medium dielectric constants

Weighing powder materials according to the mixture ratio in the table 1, then putting the prepared powder materials into a ball mill, and adding deionized water: zirconia balls: ball milling for 5 hours at a rotation speed of 300 r/min at a ratio of 3:3:1, drying the mixed material at 120 ℃, grinding and sieving with a 100-mesh sieve. Taking 1.5g of the powder, adding 20-30 drops of 6.5 wt% PVA (polyvinyl alcohol) aqueous solution for granulation, and then pressing under 250MPa to obtain wafers and cylinders with the diameter of 10 mm; placing the formed wafer and the cylinder into a sintering furnace, heating to 550 ℃ at the heating rate of 2 ℃/min, and keeping the temperature for 2 hours to carry out blank glue removal; and then, heating to 850-900 ℃ at the heating rate of 5 ℃/min, preserving heat for 0.5-2 hours, sintering, and naturally cooling along with the furnace to obtain ceramic wafers and cylindrical samples. The microwave dielectric properties of the ceramic samples were then tested and the results are shown in Table 2 (disc sample test dielectric constant, insulation resistance, cylindrical sample test Qxf and τ)_f)。

TABLE 2 microwave Performance parameter Table for the examples in TABLE 1

By comparing the above examples, the sample prepared in example 20 has the best combination of properties, and the surface (a) and cross-section (b) of the sample are shown in FIG. 1 as a topographical map. As can be seen, the sample structure is compact, and the requirement of the LTCC process on the compactness of the material is met.

The embodiment of the invention can realize sintering densification within the range of 850-900 ℃, has adjustable dielectric constant within the range of 18-35, high Q x f value, small temperature coefficient of resonance frequency and excellent insulating property, and meets the requirements of products such as LTCC filters, resonators, dielectric antennas and the like on materials. Meanwhile, the invention has the advantages of rich raw materials, low cost and simple synthesis and preparation method, and is beneficial to the industrial production and application of the low-temperature co-fired ceramic material system.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A medium dielectric constant low-temperature co-fired ceramic material is characterized by comprising 50-70 parts by mass of a Ba-Ti compound, 0-5 parts by mass of powder A, 30-45 parts by mass of powder B, 2-15 parts by mass of powder C and 0-2 parts by mass of powder D; wherein,

the Ba-Ti compound comprises 30-50 parts by mass of BaCO₃And 50-70 parts by mass of TiO₂The powder A is BaZn₂Ti₄O₁₁The powder B comprises 20-45 parts by mass of Ba (OH)₂20-40 parts by mass of H₃BO₃25-50 parts by mass of ZnO and 0-5 parts by mass of La₂O₃The component of the powder C is SrTiO₃、TiO₂And CaTiO₃Wherein the powder D is MnO₂、Co₂O₃And Cr₂O₃One or more of (a).

2. The dielectric constant low-temperature co-fired ceramic material of claim 1, wherein the preparation of the Ba-Ti compound comprises:

weighing 30-50 parts by mass of BaCO₃And 50-70 parts by mass of TiO₂Putting the prepared powder into a ball mill for mixing, wherein the ball/material mass ratio is 2-15, grinding balls are zirconia balls, the ball milling time is 4-8 hours, the rotating speed is 250-450 rpm, putting the ball-milled powder into an oven for drying at 120 ℃, and sieving the powder with a 100-mesh sieve after grinding;

and (3) preserving the heat of the powder obtained after sieving at 1100-1200 ℃ for 2-6 hours, and grinding the calcined powder and sieving with a 100-mesh sieve to obtain the Ba-Ti compound.

3. The dielectric constant low temperature co-fired ceramic material of claim 1, wherein the preparation of powder a comprises:

according to BaZn₂Ti₄O₁₁Stoichiometric weighing of BaCO₃ZnO and TiO₂After being prepared, the powder is put into a ball mill for mixing, the ball/material mass ratio is 2-15, the grinding balls are zirconia balls, the ball milling time is 4-8 hours, the rotating speed is 250-450 r/min, the powder after ball milling is put into an oven for drying at 120 ℃, and the powder is ground and then passes through a 100-mesh sieve;

and (3) preserving the heat of the sieved powder at 1100-1200 ℃ for 2-6 hours, and grinding the calcined powder and sieving the ground powder with a 100-mesh sieve to obtain powder A.

4. The dielectric constant low temperature co-fired ceramic material of claim 1, wherein the preparation of powder B comprises:

weighing 0-5 parts by mass of La₂O₃20 to 45 parts by mass of Ba (OH)₂20-40 parts by mass of H₃BO₃And 25-50 parts by mass of ZnO, mixing the powder in a ball mill at a ball/material mass ratio of 2-15, wherein the grinding balls are zirconia balls, the ball milling time is 4-8 hours, the rotating speed is 250-450 rpm, drying the powder subjected to ball milling in an oven at 80 ℃, and sieving the powder with a 100-mesh sieve after grinding;

and (3) preserving the heat of the sieved powder at 600-700 ℃ for 2-6 hours, and grinding the calcined powder and sieving the ground powder with a 100-mesh sieve to obtain powder B.

5. The method for preparing a low-temperature co-fired ceramic material with a dielectric constant as claimed in claim 1, specifically comprising:

weighing 50-70 parts by mass of Ba-Ti compound, 0-5 parts by mass of powder A, 30-45 parts by mass of powder B, 2-15 parts by mass of powder C and 0-2 parts by mass of powder D; wherein the powder C is SrTiO₃、TiO₂And CaTiO₃Wherein the powder D is MnO₂、Co₂O₃And Cr₂O₃One or more of;

putting the prepared powder into a ball mill for mixing, wherein grinding balls are zirconia balls, the ball/material mass ratio is 2-15, the ball milling time is 4-8 hours, the rotating speed is 250-450 rpm, putting the ball-milled powder into an oven for drying at 120 ℃, and sieving the powder with a 100-mesh sieve after grinding;

taking 1.5g of powder, adding 20-30 drops of 6.5 wt% PVA aqueous solution for granulation, and then preparing wafers and cylinders with the diameter of 10mm under the pressure of 250 MPa;

and (3) putting the formed wafer and the cylinder into a sintering furnace, raising the temperature to 550 ℃ at the rate of 2 ℃/min, preserving the heat for 2 hours, discharging the glue from the blank, raising the temperature to 850-900 ℃ at the rate of 5 ℃/min, preserving the heat for 0.5-2 hours, sintering, and naturally cooling along with the furnace to obtain the ceramic wafer and the cylinder.