CN102765933B - High Q*f value microwave ceramic dielectric material and preparation method thereof - Google Patents

Abstract

The invention discloses a high Q*f value microwave ceramic dielectric material (Q is equal to 1/tan delta and represents the quality factor of the material, and f represents resonance frequency, as Q changes with the f , while the Q*f value maintains the same, the Q*f value is adopted to measure the microwave dielectric ceramics loss) and belongs to the technical field of ceramic material process. The microwave ceramic dielectric material has a general chemical formula of Li(6-3x)/(3-2x)Ti(3-3x)/(3-2x)O(9-9x)/(3-2x)F3x/(3-2x), or Li(6-3x)/(3-2x)Sn(3-3x)/(3-2x)O(9-9x)/(3-2x)F3x/(3-2x), wherein x is less than or equal to 0.040 and is larger than or equal to 0.05. The preparation method is as follows: as chemical stoichiometric ratio, weighing materials and mixing; placing the mixed materials in a resin ball milling pot for 24 hours, wherein the ratio of materials, ball to alcohol by mass is 1:4:0.8; obtaining the materials and drying; calcining the materials in 800 DEG C so as to synthesize ceramic powder material; obtaining the powder bodies after the powder material is subjected to processes of crushing, secondary ball milling, discharging, drying and screening, and adding the powder bodies in a polyvinyl alcohol solution for granulation; allowing the granules to be subjected to dry pressing under a 100-150 MPa pressure so as to obtain blocks; and sintering the blocks in a 850-1,200 DEG C by buried powder in the same components so as to obtain the high Q*f value microwave ceramic dielectric material.

Description

A kind of high Q × f value microwave dielectric ceramic materials and preparation method thereof

Technical field

The present invention relates to a kind of high Q × f value microwave dielectric ceramic materials and preparation method thereof, belong to special ceramic material Technology field.

Background technology

The universal Highgrade integration to microwave communication equipment of mobile communication equipment, miniaturization, high reliability and low cost are had higher requirement.Because the wavelength of hertzian wave in Medium Wave Guide is only (the ε in freeboard _r) ^-1/2, therefore the application of Medium Wave Guide can make the size of waveguide component narrow down to original (ε _r) ^-1/2doubly.In addition, because the beginning of Medium Wave Guide exists complete magnetic interface and produces radiation loss, this can make again the size of whole waveguide component further dwindle.In a word, only have and apply the dielectric material with good Study on microwave dielectric property, just can make the Highgrade integration of microwave device, miniaturization, high reliability and cost degradation become possibility.For this reason, microwave dielectric material must have (1) high specific inductivity; (2) high quality factor q (low dielectric loss); (3) approach zero temperature coefficient of resonance frequency.

In the microwave dielectric material of high Q × f value, Ba (Mg _1/3ta _2/3) O ₃(BMT) stupalith of series enjoys favor because having very high Q × f value.But due to Ta ₂o ₅raw material resources are limited and expensive, add that the preparation of BMT needs at high temperature insulation for a long time (as 1600 ℃ of insulations 24 hours), very large to the consumption of the energy, thereby limited to a great extent the application of BMT based material.Various countries scientist and researchist are at the stupalith of actively finding a kind of novel alternative BMT based material.

The present invention, on the microwave-medium ceramics basis of research rock salt structure, provides a kind of microwave dielectric ceramic materials of high Q × f value.The advantage of invention is to prepare with cheaper cost of material and relatively low sintering temperature (lower than 1200 ℃) microwave dielectric ceramic materials of high Q × f value.

Summary of the invention

The object of the present invention is to provide a kind of high Q × f value microwave dielectric ceramic materials.

For achieving the above object, the present invention adopts following scheme:

A kind of high Q × f value microwave dielectric ceramic materials of the present invention, is characterized in that this material has following chemical formula: Li _{(6-3x)/(3-2x)}ti _{(3-3x)/(3-2x)}o _{(9-9x)/(3-2x)}f _{3x/ (3-2x)}(0.05≤x≤0.4) or Li _{(6-3x)/(3-2x)}sn _{(3-3x)/(3-2x)}o _{(9-9x)/(3-2x)}f _{3x/ (3-2x)}(0.05≤x≤0.40); Wherein x is molar fraction.

The preparation method of a kind of high Q × f value microwave dielectric ceramic materials of the present invention, is characterized in that having following process and step:

A. according to above-mentioned each chemical formula, calculate the quality of required each raw material; Adopt analytical pure raw material, 99.9% Li ₂cO ₃; 99.7% TiO ₂; 99.5% SnO ₂; 99.9% LiF;

B. by weighing accurately various raw materials pour in resin balls grinding jar, add alcohol and ZrO ₂abrading-ball; Three's weight ratio is: material: ball: alcohol=1:4:0.8; Ball milling 24 hours, mixes rear discharging, and it is dried at 100 ℃;

C. then at 800 ℃, calcine 2 hours, to synthesize porcelain;

D. synthetic above-mentioned porcelain is poured in ball grinder and carried out secondary ball milling 24 hours; The constant rate of material, ball, alcohol; Discharging, slurry is crossed 40 mesh sieves after drying;

E. the polyvinyl alcohol solution that the concentration that adds 7-10wt% in the powder obtaining is 10wt% carries out granulation; And mistake 40 mesh sieves;

F. the powder of making grain is put into mould, dry-pressing formed under 100-150MPa pressure is the right cylinder of 10*5mm; Then by the block of forming, at 600 ℃, constant temperature 2 hours is with except no-bonder, and its temperature rise rate is 5 ℃/min; Finally with identical temperature rise rate at 850-1200 ℃ with the powder powder embedded sintering of same component 2 hours, the required microwave dielectric ceramic materials of finally making.

Embodiment

Now the embodiment of the microwave dielectric ceramic materials of chemical formula composition of the present invention is described below:

Embodiment 1

According to Li _{(6-3x)/(3-2x)}ti _{(3-3x)/(3-2x)}o _{(9-9x)/(3-2x)}f _{3x/ (3-2x)}(0.05≤x≤0.40), converses the required quality of each raw material, then accurately weighs each analytical pure raw material: Li ₂cO ₃(99.9%); TiO ₂(99.7%); LiF(99.9%).Feed proportioning table is as shown in table 1 below.

Table 1 Li _{(6-3x)/(3-2x)}ti _{(3-3x)/(3-2x)}o _{(9-9x)/(3-2x)}f _{3x/ (3-2x)}allocation sheet (g)

Chemical formula	Li 2CO 3	TiO 2	LiF
				Li 2.0172Ti 0.9828O 2.9483F 0.0517	29.5859	32.0424	0.5466
Li 2.0357Ti 0.9643O 2.8929F 0.1071	29.5859	32.0424	1.1540

The each raw material accurately weighing is packed in resin balls grinding jar, add alcohol and ZrO ₂abrading-ball; Three's weight ratio is: material: ball: alcohol=1:4:0.8; Ball milling 24 hours, mixes rear discharging, and it is dried at 100 ℃; Then at 800 ℃, calcine 2 hours, to synthesize porcelain; Synthetic above-mentioned porcelain is poured in ball grinder and carried out secondary ball milling 24 hours; The constant rate of material, ball, alcohol; Discharging, slurry is crossed 40 mesh sieves after drying; The polyvinyl alcohol solution that the concentration that adds 7-10wt% in the powder obtaining is 10wt% carries out granulation; And mistake 40 mesh sieves; The powder of making grain is put into mould, and dry-pressing formed under 100-150MPa pressure is the right cylinder of 10*5mm; Then by the block of forming, at 600 ℃, constant temperature 2 hours is with except no-bonder, and its temperature rise rate is 5 ℃/min; Finally with identical temperature rise rate at 850-1200 ℃ with the powder powder embedded sintering of same component 2 hours, the required microwave dielectric ceramic materials of finally making.

Network analyzer (Agilent N5230A) and relevant necessary instrument are tested its microwave dielectric property, test frequency: 5 ~ 11GHz.The dielectric properties test result of sample is in table 2.

Embodiment 2

According to Li _{(6-3x)/(3-2x)}sn _{(3-3x)/(3-2x)}o _{(9-9x)/(3-2x)}f _{3x/ (3-2x)}(0.05≤x≤0.40), converses the required quality of each raw material, then accurately weighs each analytical pure raw material: Li ₂cO ₃(99.9%); SnO ₂(99.5%); LiF(99.9%).The allocation sheet of raw material is as shown in table 3 below.

Table 3. Li _{(6-3x)/(3-2x)}sn _{(3-3x)/(3-2x)}o _{(9-9x)/(3-2x)}f _{3x/ (3-2x)}allocation sheet (g)

Chemical formula	Li 2CO 3	SnO 2	LiF
				Li 2.0172Ti 0.9828O 2.9483F 0.0517	16.2723	33.3225	0.3007
Li 2.0357Ti 0.9643O 2.8929F 0.1071	16.2723	33.3225	0.6347

The each raw material accurately weighing is packed in resin balls grinding jar, add alcohol and ZrO ₂abrading-ball; Three's weight ratio is: material: ball: alcohol=1:4:0.8; Ball milling 24 hours, mixes rear discharging, and it is dried at 100 ℃; Then at 800 ℃, calcine 2 hours, to synthesize porcelain; Synthetic above-mentioned porcelain is poured in ball grinder and carried out secondary ball milling 24 hours; The constant rate of material, ball, alcohol; Discharging, slurry is crossed 40 mesh sieves after drying; The polyvinyl alcohol solution that the concentration that adds 7-10wt% in the powder obtaining is 10wt% carries out granulation; And mistake 40 mesh sieves; The powder of making grain is put into mould, and dry-pressing formed under 100-150MPa pressure is the right cylinder of 10*5mm; Then by the block of forming, at 600 ℃, constant temperature 2 hours is with except no-bonder, and its temperature rise rate is 5 ℃/min; Finally with identical temperature rise rate at 850-1200 ℃ with the powder powder embedded sintering of same component 2 hours, the required microwave dielectric ceramic materials of finally making.

Network analyzer (Agilent N5230A) and relevant necessary instrument are tested its microwave dielectric property, test frequency: 5 ~ 11GHz.The dielectric properties test result of sample is in table 4.

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Claims (2)

1. high Q × f value microwave dielectric ceramic materials, is characterized in that this material has following chemical formula: Li _{(6-3x)/(3-2x)}ti _{(3-3x)/(3-2x)}o _{(9-9x)/(3-2x)}f _{3x/ (3-2x)}(0.05≤x≤0.40) or Li _{(6-3x)/(3-2x)}sn _{(3-3x)/(3-2x)}o _{(9-9x)/(3-2x)}f _{3x/ (3-2x)}(0.05≤x≤0.40); Wherein x is molar fraction.

2. a preparation method for high Q × f value microwave dielectric ceramic materials, is characterized in that this material has following process and step:

A. according to above-mentioned each chemical formula, calculate the quality of required each raw material; Adopt analytical pure raw material, 99.9% Li ₂cO ₃; 99.7% TiO ₂; 99.5% SnO ₂; 99.9% LiF;

B. by weighing accurately various raw materials pour in resin balls grinding jar, add alcohol and ZrO ₂abrading-ball; Three's weight ratio is: material: ball: alcohol=1:4:0.8; Ball milling 24 hours, mixes rear discharging, and it is dried at 100 ℃;

C. then at 800 ℃, calcine 2 hours, to synthesize porcelain;

D. synthetic above-mentioned porcelain is poured in ball grinder and carried out secondary ball milling 24 hours; The constant rate of material, ball, alcohol; Discharging, slurry is crossed 40 mesh sieves after drying;

E. the polyvinyl alcohol solution that the concentration that adds 7-10wt% in the powder obtaining is 10wt% carries out granulation; And mistake 40 mesh sieves;

F. the powder of making grain is put into mould, dry-pressing formed under 100-150MPa pressure is the right cylinder of 10*5mm; Then by the block of forming, at 600 ℃, constant temperature 2 hours is with except no-bonder, and its temperature rise rate is 5 ℃/min; Finally with identical temperature rise rate at 850-1200 ℃ with the powder powder embedded sintering of same component 2 hours, the required microwave dielectric ceramic materials of finally making.