CN103342558B - Low temperature sintering microwave dielectric ceramic Ba 3ti 2v 4o 17and preparation method thereof - Google Patents

Abstract

The invention discloses a kind of low temperature sintering microwave dielectric ceramic Ba ₃ti ₂v ₄o ₁₇and preparation method thereof.Can low-temperature sintering vanadate microwave dielectric ceramic material consist of Ba ₃ti ₂v ₄o ₁₇.(1) be the BaCO of more than 99.9% by purity ₃, TiO ₂and V ₂o ₅starting powder press Ba ₃ti ₂v ₄o ₁₇chemical formula weigh batching.(2) step (1) raw material wet ball-milling is mixed 12 hours, solvent is distilled water, pre-burning 6 hours in 750 DEG C of air atmosphere after oven dry.(3) in the powder that step (2) is obtained, binding agent is added and after granulation, more compressing, finally in 830 ~ 850 DEG C of air atmosphere, sinter 4 hours; Described binding agent adopts mass concentration to be the poly-vinyl alcohol solution of 5%, and dosage accounts for 3% of powder gross mass.Pottery prepared by the present invention is good at 850-900 DEG C of sintering, and its dielectric constant reaches 15 ~ 16, and quality factor q f value is up to 77000-93000GHz, and temperature coefficient of resonance frequency is little, and can be low temperature co-fired with Ag electrode, industrially has great using value.

Description

Low temperature sintering microwave dielectric ceramic Ba 3ti 2v 4o 17and preparation method thereof

Technical field

The present invention relates to dielectric ceramic material, particularly relate to microwave dielectric ceramic material of the microwave devices such as medium substrate, resonator and the filter used in microwave frequency and preparation method thereof.

Background technology

Microwave dielectric ceramic refers to and is applied to microwave frequency band (mainly UHF, SHF frequency range) complete the pottery of one or more functions as dielectric material in circuit, resonator is widely used as in modern communication, filter, the components and parts such as dielectric substrate and medium wave circuit, it is the key foundation material of modern communication technology, at portable mobile phone, automobile telephone, cordless telephone, there is very important application the aspects such as telstar recipient and military radar, in the miniaturization of modern communication instrument, increasing effect is just being played in integrated process.

Be applied to the dielectric ceramic of microwave frequency band, the requirement of following dielectric property should be met: (1) seriation DIELECTRIC CONSTANT ε _rto adapt to the requirement of different frequency and different application occasion; (2) high quality factor q value or dielectric loss tan δ are to reduce noise, and one requires Qf>=3000GHz; (3) the temperature coefficient τ of resonance frequency _flittle of as far as possible to ensure the thermal stability that device has had, one requires-10/ DEG C≤τ _f≤+10ppm/ DEG C.From late 1930s, just someone attempts dielectric substance to be applied to microwave technology in the world.

According to relative dielectric constant ε _rsize from use frequency range different, usually the microwave-medium ceramics be developed and developing can be divided into 4 classes.

(1) ultralow dielectric microwave dielectric ceramic, main representative is Al ₂o ₃-TiO ₂, Y ₂baCuO ₅, MgAl ₂o ₄and Mg ₂siO ₄deng, its ε _r≤ 20, quality factor q × f>=50000GHz, τ _f≤ 10ppm/ DEG C.Be mainly used in microwave base plate and high-end microwave device.

(2) low ε _rwith the microwave dielectric ceramic of high q-factor, mainly BaO-MgO-Ta ₂o ₅, BaO-ZnO-Ta ₂o ₅or BaO-MgO-Nb ₂o ₅, BaO-ZnO-Nb ₂o ₅system or the hybrid system MWDC material between them.Its ε _r=25 ~ 30, Q=(1 ~ 2) × 10 ⁴(under f>=10GHz), τ _f≈ 0.Be mainly used in the microwave communication equipments such as the direct broadcasting satellite of f >=8GHz as dielectric resonance device.

(3) medium ε _rwith the microwave dielectric ceramic of Q value, mainly with BaTi ₄o ₉, Ba ₂ti ₉o ₂₀(Zr, Sn) TiO ₄deng the MWDC material for base, its ε _r=35 ~ 40, Q=(6 ~ 9) × 10 ³(under f=3 ~-4GHz), τ _f≤ 5ppm/ DEG C.Be mainly used in microwave military radar in 4 ~ 8GHz frequency range and communication system as dielectric resonance device.

(4) high ε _rand the microwave dielectric ceramic that Q value is lower, be mainly used in civilian mobile communcations system in 0.8 ~ 4GHz frequency range, this is also the emphasis of microwave dielectric ceramic research.Since the eighties, the people such as Kolar, Kato in succession find and have studied perovskite-like tungsten bronze type BaO-Ln ₂o ₃-TiO ₂series (Ln=La, Sm, Nd or Pr etc. are called for short BLT system), complex perovskite structure CaO-Li ₂o-Ln ₂o ₃-TiO ₂series, lead base series material, Ca _1-xln _2x/3tiO ₃be contour ε _rmicrowave dielectric ceramic, the wherein BaO-Nd of BLT system ₂o ₃-TiO ₂material dielectric constant reaches 90, lead base series (Pb, Ca) ZrO ₃dielectric constant reaches 105.

Above these material systems sintering temperature one higher than 1300 DEG C, can not directly and the low-melting-point metal such as Ag and Cu burn formation multilayer ceramic capacitor altogether.In recent years, along with LTCC Technology (Low Temperature Co-fired Ceramics, the requirement of development LTCC) and the development of microwave multilayer device, researcher both domestic and external has carried out exploring widely and studying to some low fever's system materials, mainly adopt devitrified glass or glassceramic composites system, because low-melting glass has relatively high dielectric loss mutually, the existence of glassy phase substantially increases the dielectric loss of material.Therefore development is the emphasis of current research without the low fired microwave dielectric ceramic material of glassy phase.

Can in the process of low fired microwave dielectric ceramic materials in exploration and development of new, the material systems such as the Li based compound that intrinsic sintering temperature is low, Bi based compound, tungstates architecture compound and tellurate architecture compound get the attention and research, due to containing the compound such as Bi, Te and Mo easily and Ag electrode generation interfacial reaction and raw material TeO ₂poisonous the application of these Bi, Te and Mo sills is restricted, therefore can the high performance microwave media ceramic system of low fever still very limited, which greatly limits the development of low temperature co-fired technology and microwave multilayer device.

Summary of the invention

The object of this invention is to provide and a kind of there is low-loss and good thermal stability, microwave dielectric ceramic material that sintering temperature is low simultaneously and preparation method thereof.

The chemical composition of the low temperature sintering microwave dielectric ceramic material that the present invention relates to is: Ba ₃ti ₂v ₄o ₁₇.

Preparation method's concrete steps of described low temperature sintering microwave dielectric ceramic are:

(1) be the BaCO of more than 99.9% by purity ₃, TiO ₂and V ₂o ₅starting powder press Ba ₃ti ₂v ₄o ₁₇chemical formula weigh batching.

(2) step (1) raw material wet ball-milling is mixed 12 hours, solvent is distilled water, pre-burning 6 hours in 750 DEG C of air atmosphere after oven dry.

(3) in the powder that step (2) is obtained, binding agent is added and after granulation, more compressing, finally in 830 ~ 850 DEG C of air atmosphere, sinter 4 hours; Described binding agent adopts mass concentration to be the poly-vinyl alcohol solution of 5%, and dosage accounts for 3% of powder gross mass.

Pottery prepared by the present invention is good at 830-850 DEG C of sintering, its dielectric constant reaches 15 ~ 16, and quality factor q f value is up to 77000-93000GHz, and temperature coefficient of resonance frequency is little, and can be low temperature co-fired with Ag electrode, therefore industrially there is great using value.

Embodiment

Embodiment:

Table 1 shows 3 specific embodiments and microwave dielectric property thereof that form different sintering temperature of the present invention.Its preparation method is described above, carries out the evaluation of microwave dielectric property by cylindrical dielectric resonator method; Powder is mixed with the Ag powder accounting for powder quality 20%, compressing after, at 880 DEG C of sintering; X-ray diffraction material phase analysis and scanning electron microscopic observation all show Ba ₃ti ₂v ₄o ₁₇chemical reaction is not there is not, i.e. Ba with Ag ₃ti ₂v ₄o ₁₇can be low temperature co-fired with Ag electrode.

The present invention is never limited to above embodiment.Bound, the interval value of sintering temperature can realize the present invention, do not enumerate embodiment at this.

This pottery can be widely used in the manufacture of the microwave devices such as various medium substrate, resonator and filter, can meet the technology needs of the system such as mobile communication, satellite communication.

Table 1:

Claims (1)

1. vanadate is as can the application of low-temperature sintered microwave dielectric ceramic, it is characterized in that the chemical constitution formula of described vanadate is: Ba ₃ti ₂v ₄o ₁₇;

Preparation method's concrete steps of described vanadate are:

(1) be the BaCO of more than 99.9% by purity ₃, TiO ₂and V ₂o ₅starting powder press Ba ₃ti ₂v ₄o ₁₇chemical formula weigh batching;

(2) step (1) raw material wet ball-milling is mixed 12 hours, solvent is distilled water, pre-burning 6 hours in 750 DEG C of air atmosphere after oven dry;

(3) in the powder that step (2) is obtained, binding agent is added and after granulation, more compressing, finally in 830 ~ 850 DEG C of air atmosphere, sinter 4 hours; Described binding agent adopts mass concentration to be the poly-vinyl alcohol solution of 5%, and dosage accounts for 3% of powder gross mass.