CN102060532B - High-quality factor microwave medium ceramic and preparation method thereof - Google Patents

Abstract

The invention relates to high-quality factor microwave medium ceramic and a preparation method thereof. The material composition of the high-quality factor microwave medium ceramic is expressed as (0.7ZnNb2O6-0.3Zn3Nb2O8)-x molar percent ZnAl2O4, wherein x is equal to 0.5 to 8. The preparation method comprises: ball milling and mixing 0.7ZnNb2O6-0.3Zn3Nb2O8 powder and ZnAl2O4 powder; and drying, screening, granulating, forming, rubber discharging and sintering to obtain a microwave medium ceramic material. The microwave medium ceramic material is stable in process and high in repeatability, has high microwave dielectric performance and quality factor, a dielectric constant of 20 to 24, a high Q*f value (more than 60,000 GHz) and a small resonant frequency-temperature factor (less than or equal to +/-30ppm/DEG C), and is suitable for manufacturing chip type high-frequency capacitors, chip type medium resonators, filters, microwave medium antennae and other elements and devices.

Description

A kind of high-quality factor microwave medium ceramic and preparation method thereof

Technical field

The present invention relates to the microwave dielectric ceramic materials field, particularly a kind of high-quality factor microwave medium ceramic and preparation method thereof of material subject.

Background technology

Microwave-medium ceramics refers to be applied in the microwave frequency band circuit as dielectric material and finishes the stupalith of one or more functions, be suitable for making various microwave devices, such as frequency stabilization resonator, wave filter and the frequency discriminator in the equipment such as electronic countermeasure, navigation, communication, radar, family expenses direct broadcasting satellite television receiver and mobile telephone, can also be as the carrier of microwave circuit, polyrod antenna, Medium Wave Guide loop etc.Along with developing rapidly of mobile communication and satellite communication technology, make the communication terminal will be towards miniaturization, lightweight, integrated, high reliability and future development cheaply, the needs of the microwave-medium ceramics that the microwave devices such as dielectric resonator and wave filter are used be just growing.

In the situation that other condition is identical, adopt the higher material of quality factor to make microwave device and will obviously change its insertion loss performance, therefore, the quality factor of microwave material (Q * f value) are to weigh the important indicator of microwave material quality.Since the loss of dielectric resonance device by dielectric loss and dielectric upholder and on every side the conductor losses of metal vessel form, only have low-loss microwave-medium ceramics of use, just might make the resonator of high quality factor.In addition, the dielectric resonance device generally all is as its mid-frequency, if temperature coefficient of resonance frequency (τ with the resonant frequency of certain vibration modes of microwave-medium ceramics _f) excessive, then the mid-frequency of device will produce with the variation of Yin Wendu large drift, thus the normal steady operation of device; Therefore, microwave device generally all requires microwave-medium ceramics to have high quality factor (Q * f value) and little temperature coefficient of resonance frequency (τ _f).

In addition, the development of present mobile communication technology, the progress of portable mobile communication equipment has caused various multi-chip high-frequency elements and has adopted the multilevel integration technology (MLIC) under the microwave frequency developed gradually, and multilayer chip element (comprises the chip microwave dielectric resonator, wave filter and have chip ceramic capacitor of good high frequency use properties etc.) be the unique channel of realizing this goal, the chip type of microwave device needs microwave dielectric material to burn altogether with the metal electrode of high conductivity, and this just requires microwave dielectric material can realize low-temperature sintering.Yet, although representative microwave dielectric ceramic materials such as zirconia titanate tin, barium oxide-titanium dioxide and tantalum zincic acid barium, BMT etc. have high quality factor (Q * f value) at present, but sintering temperature is all at 1300 ℃～1500 ℃, because its sintering temperature is too high, when the preparation microwave device, can only use and contain the high silver palladium alloy of palladium amount, even pure palladium is as electrode materials, greatly improved the raw materials cost of components and parts, and high sintering temperature needs to consume the more energy in preparation process, increases preparation cost.

Adopt at present the technology that reduces sintering temperature that chemical synthesis, special sintering method (hot pressed sintering, microwave sintering, HIP sintering etc.) and doped sintered auxiliary agent etc. are arranged, when reducing sintering temperature, all in various degree reduction the quality factor of microwave dielectric ceramic materials, and can increase temperature coefficient of resonance frequency, be difficult to use.Therefore, how when reducing sintering temperature, guarantee that microwave dielectric ceramic materials has high quality factor (Q * f value) and little temperature coefficient of resonance frequency (τ _f) just become present technological difficulties.

Summary of the invention

The sintering temperature that exists in the prior art is high in order to overcome, expensive raw material price, preparation cost is high, energy consumption is high and the material microwave quality factor are low problem.The present invention proposes a kind of high-quality factor microwave medium ceramic and preparation method thereof.

Technical solution of the present invention is: a kind of high-quality factor microwave medium ceramic material, this microwave dielectric ceramic materials mol ratio composition formula is: (0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈)-x%ZnAl ₂O ₄, x=0.5～8, x is for accounting for 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈The molecular fraction of total mole number.

This microwave dielectric ceramic materials is by ZnNb ₂O ₆, Zn ₃Nb ₂O ₈ZnAl with spinel structure ₂O ₄Consist of mutually.

The present invention at first adopts ZnO, Nb ₂O ₅And Al ₂O ₃For starting material synthesize separately ZnNb ₂O ₆Powder, Zn ₃Nb ₂O ₈Powder and ZnAl ₂O ₄Powder is then with ZnNb ₂O ₆Powder and Zn ₃Nb ₂O ₈Powder is according to 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Composition mix, adopt synthetic 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder and ZnAl ₂O ₄The powder ball milling mixes, through oven dry, sieve, granulation, moulding, binder removal and sintering namely obtain microwave dielectric ceramic materials of the present invention.

Preparation technology's concrete steps of the present invention are as follows:

(1) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnNb in 4 hours 1000 ℃ of lower calcinings ₂O ₆

(2) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 3: 1 in molar ratio mixing and ball milling were prepared Zn in 4 hours 1150 ℃ of lower calcinings ₃Nb ₂O ₈

(3) with analytically pure ZnO and Al ₂O ₃12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnAl in 4 hours 1100 ℃ of lower calcinings ₂O ₄

(4) with ZnNb ₂O ₆With Zn ₃Nb ₂O ₈12 hours post-dryings of 7: 3 in molar ratio mixing and ball milling are prepared 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder.

(5) with 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder and ZnAl ₂O ₄Powder mixes by proportioning, and ball milling is 12 hours again, crosses 100 eye mesh screens after the oven dry;

(6) powder after above-mentioned the sieving is added 5% poly (vinyl alcohol) binder aqueous solution granulation, produce 200 microns particle, and compression moulding under 100Mpa pressure;

(7) the base substrate binder removal after the moulding, dump temperature is 500 ℃, and temperature rise rate is 2 ℃/minute, and soaking time 1 hour is removed binding agent;

(8) with the base substrate behind the binder removal at 1100 ℃～1150 ℃ sintering, temperature rise rate is 5 ℃/minute, soaking time is 2～6 hours.

The present invention according to different needs, only needs to change ZnAl when not changing preparation technology ₂O ₄Content, (Q * f) is greater than the microwave dielectric ceramic materials of 60000GHz, and the temperature coefficient of resonance frequency that still guarantees pottery is less than ± 30ppm/ ℃ just can to obtain quality factor under the microwave frequency band.

The invention provides and under lower temperature, (≤1150 ℃) to sinter porcelain into, under microwave frequency band, have simultaneously high Q * f value (＞60000GHz), temperature coefficient of resonance frequency is less than ± 30ppm/ ℃ microwave-medium ceramics, advantage is to use equipment commonly used such as ball mill, resistance furnace, baking oven etc., employing is easy to obtain and cheap raw material and simple operational path, realize the low-temperature sintering of microwave-medium ceramics, be applicable to make the chip high frequency capacitor, the sheet medium resonator, dielectric filter, the microwave frequency components and parts such as polyrod antenna significantly reduce cost of manufacture.

Description of drawings

Fig. 1 is microwave-medium ceramics preparation method's schema.

Fig. 2 is the XRD figure spectrum of embodiment one microwave-medium ceramics.

Fig. 3 is the XRD figure spectrum of embodiment two microwave-medium ceramics.

Fig. 4 is the XRD figure spectrum of embodiment three microwave-medium ceramics.

Fig. 5 is the XRD figure spectrum of embodiment four microwave-medium ceramics.

Embodiment

Further set forth substantive features of the present invention and marked improvement below by embodiment, yet the present invention only limits to absolutely not described embodiment.

Embodiment one:

The present embodiment is with analytically pure ZnO, Nb ₂O ₅And Al ₂O ₃, by (0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈)-xmol%ZnAl ₂O ₄Stoichiometric ratio batching, x=0.5 wherein.

Preparation process is:

(1) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnNb in 4 hours 1000 ℃ of lower calcinings ₂O ₆

(2) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 3: 1 in molar ratio mixing and ball milling were prepared Zn in 4 hours 1150 ℃ of lower calcinings ₃Nb ₂O ₈

(3) with analytically pure ZnO and Al ₂O ₃12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnAl in 4 hours 1100 ℃ of lower calcinings ₂O ₄

(4) with ZnNb ₂O ₆With Zn ₃Nb ₂O ₈12 hours post-dryings of 7: 3 in molar ratio mixing and ball milling are prepared 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder.

(5) with 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder and ZnAl ₂O ₄Powder mixes by proportioning, and ball milling is 12 hours again, crosses 100 eye mesh screens after the oven dry;

(6) powder after above-mentioned the sieving is added 5% poly (vinyl alcohol) binder aqueous solution granulation, produce 200 microns particle, and compression moulding under 100Mpa pressure;

(7) the base substrate binder removal after the moulding, dump temperature is 500 ℃, and temperature rise rate is 2 ℃/minute, and soaking time 1 hour is removed binding agent;

(8) with the base substrate behind the binder removal at 1100 ℃ of sintering, temperature rise rate is 5 ℃/minute, soaking time is 2 hours.

Analyze with the ceramic sample of X-ray diffraction technology after to sintering, the result has formed as shown in Figure 2 by ZnNb ₂O ₆, Zn ₃Nb ₂O ₈ZnAl with spinel structure ₂O ₄The multiphase structure of phase composite.The microwave dielectric property that adopts HP8720 type network analyzer to test out material is: ε=24.3, Q * f=74647GHz, τ _f=-19.7ppm/ ℃.

Embodiment two:

The present embodiment is with analytically pure ZnO, Nb ₂O ₅And Al ₂O ₃, by (0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈)-xmol%ZnAl ₂O ₄Stoichiometric ratio batching, x=2 wherein.

Preparation process is:

(1) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnNb in 4 hours 1000 ℃ of lower calcinings ₂O ₆

(2) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 3: 1 in molar ratio mixing and ball milling were prepared Zn in 4 hours 1150 ℃ of lower calcinings ₃Nb ₂O ₈

(3) with analytically pure ZnO and Al ₂O ₃12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnAl in 4 hours 11002 times calcinings ₂O ₄

(4) with ZnNb ₂O ₆With Zn ₃Nb ₂O ₈12 hours post-dryings of 7: 3 in molar ratio mixing and ball milling are prepared 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder.

(5) with 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder and ZnAl ₂O ₄Powder mixes by proportioning, and ball milling is 12 hours again, crosses 100 eye mesh screens after the oven dry;

(6) powder after above-mentioned the sieving is added 5% poly (vinyl alcohol) binder aqueous solution granulation, produce 200 microns particle, and compression moulding under 100Mpa pressure;

(7) the base substrate binder removal after the moulding, dump temperature is 500 ℃, and temperature rise rate is 2 ℃/minute, and soaking time 1 hour is removed binding agent;

(8) with the base substrate behind the binder removal at 1100 ℃ of sintering, temperature rise rate is 5 ℃/minute, soaking time is 6 hours.

Analyze with the ceramic sample of X-ray diffraction technology after to sintering, the result has formed as shown in Figure 3 by ZnNb ₂O ₆, Zn ₃Nb ₂O ₈ZnAl with spinel structure ₂O ₄The multiphase structure of phase composite.The microwave dielectric property that adopts HP8720 type network analyzer to test out material is: ε=23, Q * f=85867GHz, τ _f=-25.1ppm/ ℃.

Embodiment three:

The present embodiment is with analytically pure ZnO, Nb ₂O ₅And Al ₂O ₃, by (0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈)-xmol%ZnAl ₂O ₄Stoichiometric ratio batching, x=6 wherein.

Preparation process is:

(1) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnNb in 4 hours 1000 ℃ of lower calcinings ₂O ₆

(2) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 3: 1 in molar ratio mixing and ball milling were prepared Zn in 4 hours 1150 ℃ of lower calcinings ₃Nb ₂O ₈

(3) with analytically pure ZnO and Al ₂O ₃12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnAl in 4 hours 1100 ℃ of lower calcinings ₂O ₄

(4) with ZnNb ₂O ₆With Zn ₃Nb ₂O ₈12 hours post-dryings of 7: 3 in molar ratio mixing and ball milling are prepared 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder.

(5) with 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder and ZnAl ₂O ₄Powder mixes by proportioning, and ball milling is 12 hours again, crosses 100 eye mesh screens after the oven dry;

(6) powder after above-mentioned the sieving is added 5% poly (vinyl alcohol) binder aqueous solution granulation, produce 200 microns particle, and compression moulding under 100Mpa pressure;

(7) the base substrate binder removal after the moulding, dump temperature is 500 ℃, and temperature rise rate is 2 ℃/minute, and soaking time 1 hour is removed binding agent;

(8) with the base substrate behind the binder removal at 1150 ℃ of sintering, temperature rise rate is 5 ℃/minute, soaking time is 4 hours.

Analyze with the ceramic sample of X-ray diffraction technology after to sintering, the result has formed as shown in Figure 4 by ZnNb ₂O ₆, Zn ₃Nb ₂O ₈ZnAl with spinel structure ₂O ₄The multiphase structure of phase composite.The microwave dielectric property that adopts HP8720 type network analyzer to test out material is: ε=22.4, Q * f=86467GHz, τ _f=-26.7ppm/ ℃.

Embodiment four:

The present embodiment is with analytically pure ZnO, Nb ₂O ₅And Al ₂O ₃, by (0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈)-xmol%ZnAl ₂O ₄Stoichiometric ratio batching, x=8 wherein.

Preparation process is:

(1) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnNb in 4 hours 1000 ℃ of lower calcinings ₂O ₆

(2) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 3: 1 in molar ratio mixing and ball milling were prepared Zn in 4 hours 1150 ℃ of lower calcinings ₃Nb ₂O ₈

(3) with analytically pure ZnO and Al ₂O ₃12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnAl in 4 hours 1100 ℃ of lower calcinings ₂O ₄

(4) with ZnNb ₂O ₆With Zn ₃Nb ₂O ₈12 hours post-dryings of 7: 3 in molar ratio mixing and ball milling are prepared 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder.

(5) with 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder and ZnAl ₂O ₄Powder mixes by proportioning, and ball milling is 12 hours again, crosses 100 eye mesh screens after the oven dry;

(6) powder after above-mentioned the sieving is added 5% poly (vinyl alcohol) binder aqueous solution granulation, produce 200 microns particle, and compression moulding under 100Mpa pressure;

(7) the base substrate binder removal after the moulding, dump temperature is 500 ℃, and temperature rise rate is 2 ℃/minute, and soaking time 1 hour is removed binding agent;

(8) with the base substrate behind the binder removal at 1150 ℃ of sintering, temperature rise rate is 5 ℃/minute, soaking time is 6 hours.

Analyze with the ceramic sample of X-ray diffraction technology after to sintering, the result has formed as shown in Figure 5 by ZnNb ₂O ₆, Zn ₃Nb ₂O ₈ZnAl with spinel structure ₂O ₄The multiphase structure of phase composite.The microwave dielectric property that adopts HP8720 type network analyzer to test out material is: ε=20.2, Q * f=64000GHz, τ _f=-28.4ppm/ ℃.

Claims (3)

1. high-quality factor microwave medium ceramic material, it is characterized in that: this microwave dielectric ceramic materials mol ratio composition formula is: (0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈)-x%ZnAl ₂O ₄, x=0.5～8, x% is ZnAl ₂O ₄Account for 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈The molecular fraction of total mole number, described high-quality factor microwave medium ceramic material is prepared by following methods:

(1) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnNb in 4 hours 1000 ℃ of lower calcinings ₂O ₆

(2) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 3: 1 in molar ratio mixing and ball milling were prepared Zn in 4 hours 1150 ℃ of lower calcinings ₃Nb ₂O ₈

(3) with analytically pure ZnO and Al ₂O ₃12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnAl in 4 hours 1100 ℃ of lower calcinings ₂O ₄

(4) with ZnNb ₂O ₆With Zn ₃Nb ₂O ₈12 hours post-dryings of 7: 3 in molar ratio mixing and ball milling are prepared 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder;

(5) with 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder and ZnAl ₂O ₄Powder mixes by proportioning, and ball milling is 12 hours again, crosses 100 eye mesh screens after the oven dry;

(6) powder after above-mentioned the sieving is added 5% poly (vinyl alcohol) binder aqueous solution granulation, produce 200 microns particle, and compression moulding under 100MPa pressure;

(7) the base substrate binder removal after the moulding, dump temperature is 500 ℃, and temperature rise rate is 2 ℃/minute, and soaking time 1 hour is removed binding agent;

(8) with the base substrate behind the binder removal at 1100 ℃～1150 ℃ sintering, temperature rise rate is 5 ℃/minute, soaking time is 2～6 hours.

2. a kind of high-quality factor microwave medium ceramic material as claimed in claim 1, it is characterized in that: this microwave dielectric ceramic materials is by ZnNb ₂O ₆, Zn ₃Nb ₂O ₈ZnAl with spinel structure ₂O ₄Consist of mutually.

3. prepare as claimed in claim 1 a kind of method of high-quality factor microwave medium ceramic material, it is characterized in that:

(1) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnNb in 4 hours 1000 ℃ of lower calcinings ₂O ₆

(2) with analytically pure ZnO and Nb ₂O ₅12 hours post-dryings of 3: 1 in molar ratio mixing and ball milling were prepared Zn in 4 hours 1150 ℃ of lower calcinings ₃Nb ₂O ₈

(3) with analytically pure ZnO and Al ₂O ₃12 hours post-dryings of 1: 1 in molar ratio mixing and ball milling were prepared ZnAl in 4 hours 1100 ℃ of lower calcinings ₂O ₄

(4) with ZnNb ₂O ₆With Zn ₃Nb ₂O ₈12 hours post-dryings of 7: 3 in molar ratio mixing and ball milling are prepared 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder;

(5) with 0.7ZnNb ₂O ₆-0.3Zn ₃Nb ₂O ₈Powder and ZnAl ₂O ₄Powder mixes by proportioning, and ball milling is 12 hours again, crosses 100 eye mesh screens after the oven dry;

(6) powder after above-mentioned the sieving is added 5% poly (vinyl alcohol) binder aqueous solution granulation, produce 200 microns particle, and compression moulding under 100MPa pressure;

(7) the base substrate binder removal after the moulding, dump temperature is 500 ℃, and temperature rise rate is 2 ℃/minute, and soaking time 1 hour is removed binding agent;

(8) with the base substrate behind the binder removal at 1100 ℃～1150 ℃ sintering, temperature rise rate is 5 ℃/minute, soaking time is 2～6 hours.

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