CN107382299A - A kind of low temperature preparation method of low dielectric microwave media ceramic - Google Patents

Abstract

The invention discloses a low-temperature preparation method of low-medium microwave dielectric ceramics, belonging to the technical field of microwave dielectric ceramics. According to the general chemical formula Li ₂ (Mg _1-x Zn _x )SiO ₄ , the present invention carries out batching, ball milling, drying and calcining to form a crystal phase, and then adds a composite sintering aid to the pre-sintered powder for secondary ball milling and calcining. Dry and low-temperature sintering finally yields microwave dielectric ceramic materials. The present invention can preliminarily reduce the densification temperature of microwave dielectric ceramics and improve its dielectric properties by substituting Zn ²⁺ for Mg ²⁺ ; the composite sintering aid forms a liquid phase in the subsequent sintering process, so that the sintering temperature is further reduced to 900°C, and The compactness of the microwave dielectric ceramic material is improved. The method provided by the invention is conducive to the application of Li ₂ MgSiO ₄ -based microwave dielectric ceramics with lower dielectric constant and higher quality factor in LTCC, and meets the needs of the microwave communication industry.

Description

A low-temperature preparation method of low-dielectric microwave dielectric ceramics

technical field

The invention belongs to the technical field of microwave dielectric ceramics, in particular to a low-temperature preparation method of low-medium microwave dielectric ceramics.

Background technique

Microwave dielectric ceramics refer to ceramics that are used as dielectric materials in microwave frequency circuits and perform one or more functions. They are key basic materials in modern communication technology. The performance index of microwave dielectric ceramics largely determines the performance of microwave communication devices and systems. With the further expansion of the working frequency of modern communication technology to the high-frequency range, especially after entering the millimeter wave and submillimeter wave bands, the dielectric loss of the material increases significantly, the signal transmission delay time is longer, and the signal attenuation becomes more prominent. The appearance of this phenomenon is closely related to the dielectric constant and dielectric loss of microwave dielectric ceramic materials. Therefore, in order to ensure that substrate materials and high-end microwave components obtain high-speed and high-quality transmission signals at high frequencies, it is necessary to use microwave dielectric ceramic materials with low dielectric constant and high quality factor Q. On the other hand, with the development of device functions, people hope to integrate more functions on devices with smaller volumes, so the expectations for circuit assembly density are getting higher and higher. The low temperature co-fired ceramic technology (Low Temperature Co-fired Ceramic, LTCC) is an important way to realize the miniaturization, integration, high reliability and low-cost development of components. LTCC stands out from many microelectronic integration and integration technologies because of its advantages of high frequency, low loss, high integration and high-speed transmission, and has become the mainstream way of electronic component integration. Among them, as one of the key technologies of LTCC - LTCC material technology, its biggest feature is that LTCC ceramic materials can be sintered into porcelain at a relatively low sintering temperature, and can be combined with metal electrode materials with excellent electrical conductivity such as Ag and its alloys. burn. Li ₂ MgSiO ₄ -based microwave dielectric ceramics have excellent dielectric properties, the dielectric constant is 5-6, the quality factor Q is as high as 15000 GHz, and it can be co-fired with Ag metal. Therefore, Li ₂ MgSiO ₄ -based microwave dielectric ceramics are used as A low dielectric constant microwave ceramic material has broad application prospects. However, because its sintering temperature is as high as 1250°C, it cannot be applied to LTCC. Only by lowering its sintering temperature below 960°C can it exert its excellent performance advantages in LTCC. At present, the method of adding glass as a sintering aid is usually used to reduce the sintering temperature. However, because the added glass is easy to chemically react with the glass contained in the conductive silver paste, it limits its wide application in LTCC. Therefore, how to make Li ₂ MgSiO ₄ -based microwave dielectric ceramics widely used in LTCC and overcome the above defects has become a technical problem to be solved in this field.

Contents of the invention

In order to overcome the deficiencies of the prior art, the present invention provides a low-temperature preparation method of low-medium microwave dielectric ceramics, the core idea of which is: the sintering temperature is preliminarily reduced by using ion substitution, and a liquid phase is formed during sintering by using a composite sintering aid , further reducing the sintering temperature of Li ₂ MgSiO ₄ -based microwave dielectric ceramic materials to 900 °C, while promoting dense and uniform grain growth.

In order to achieve the above object, the present invention has the following technical solutions:

A low-temperature preparation method for low-medium microwave dielectric ceramics, characterized in that it comprises the following steps:

Step A: batching; Li ₂ CO ₃ , ZnO, MgO, SiO ₂ are batched according to the general chemical formula Li ₂ (Mg _1-x Zn _x )SiO ₄ to form a mixture, the chemical general formula Li ₂ (Mg _1-x Zn _x ) The value range of x in SiO ₄ is 0<x≦0.5;

Step B: ball milling; ball milling the mixture obtained in step A to obtain a uniformly mixed first ball mill;

Step C: drying and sieving; drying and sieving the first ball mill material obtained in step B to obtain the first dry powder;

Step D: pre-calcining; pre-calcining the first dry powder obtained in step C in an atmospheric atmosphere to obtain a pre-calcined powder;

Step E: ball milling; the calcined powder obtained in step D is ball milled together with LiF and a low-melting point oxide, and the low-melting point oxide is Bi ₂ O ₃ or V ₂ O ₅ ; wherein: LiF accounts for The mass percentage of the powder is 1-4%, and the mass percentage of the low melting point oxide in the calcined powder is 1-3%, so as to obtain a uniformly mixed second ball abrasive;

Step F: drying; drying the second ball mill material obtained in step E to obtain a second dry powder;

Step G: sintering; the second dry powder obtained in step F is sintered in the atmosphere to finally obtain a Li ₂ MgSiO ₄ -based microwave dielectric ceramic material.

Further, the specific ball milling process in the step B of the present invention is: using absolute ethanol as a dispersant, using zirconia balls as a ball milling medium, according to the mass ratio of the mixture: balls: absolute ethanol is 1:3～5:1.5～ 3. Grinding, the grinding time is 6-16 hours, to obtain a uniformly mixed ball grinding material.

Specifically, the drying temperature in step C of the present invention is 70-100°C, preferably 80°C.

Further, in step D of the present invention, the pre-calcination temperature is 800-1000° C., and the pre-calcination time is 2-6 hours.

Further, the specific ball milling process in step E of the present invention is: using absolute ethanol as a dispersant, using zirconia balls as a ball milling medium, according to the mass ratio of the mixture: balls: absolute ethanol is 1:3～5:1.5～ 3. Grinding, the grinding time is 6-16 hours, to obtain a uniformly mixed ball grinding material.

Specifically, the drying temperature in step F of the present invention is 70-100°C, preferably 80°C.

Further, the sintering temperature in step G of the present invention is 850-950°C, and the sintering time is 2-6 hours;

Specifically, the heating rate during the sintering process in Step G of the present invention is 2° C./min.

Compared with prior art, the beneficial effect of the present invention is:

The invention provides a simple, reliable, low-cost, and low-temperature method for preparing low-medium microwave dielectric ceramics. The crystal phase is synthesized in the pre-firing process, and the densification temperature of microwave dielectric ceramics can be initially reduced and improved by replacing Mg ²⁺ with Zn ²⁺ Its dielectric properties; further, the present invention adds a composite sintering aid after pre-firing, wherein the composite sintering aid forms a liquid phase in the subsequent sintering process, and the generation of the liquid phase not only makes the bonding between the ceramic particles tighter but also The surface activity of the particles is improved, so that the sintering of ceramics can be significantly promoted, so that the sintering temperature of the Li ₂ (Mg _1-x Zn _x )SiO ₄ is reduced to 900°C. In addition, the volatilization of Li ⁺ in the sintering process causes voids on the grains, which affects the compactness of ceramic materials, thereby affecting its performance. LiF can overcome the above defects, avoid the generation of voids, and further improve the compactness of microwave dielectric ceramic materials. The method provided by the invention is conducive to the application of Li ₂ MgSiO ₄ -based microwave dielectric ceramics with lower dielectric constant and higher quality factor in LTCC, and meets the needs of the microwave communication industry.

Description of drawings

Fig. 1 is the XRD spectrum of Li ₂ (Mg _0.5 Zn _0.5 ) SiO ₄ ceramics prepared in Example 6;

Fig. 2 is an SEM image of the cross-section of Li ₂ (Mg _1-x Zn _x )SiO ₄ ceramics prepared in Examples 1 to 6.

detailed description

Taking Li ₂ (Mg _0.8 Zn _0.2 )SiO ₄ and Li ₂ (Mg _0.5 Zn _0.5 )SiO ₄ as examples below, the principles and characteristics of the present invention will be described in detail in conjunction with the accompanying drawings. It should be noted that the specific embodiments of the present invention are only It is used to explain the present invention, but not to limit the protection scope of the present invention.

Example 1:

The invention discloses a low-temperature preparation method of low-medium microwave dielectric ceramics, which comprises the following steps:

Step A: batching; batching Li ₂ CO ₃ , ZnO, MgO, and SiO ₂ according to the general chemical formula Li ₂ (Mg _0.8 Zn _0.2 )SiO ₄ to form a mixture;

Step B: ball milling; put the mixture prepared in step A into a polytetrafluoroethylene ball milling tank, use absolute ethanol as a dispersant, and zirconia balls as a ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol 1: 5: 1.5, ball milled on a planetary ball mill for 12 hours; obtain the first ball mill that is uniformly mixed;

Step C: drying and sieving; putting the first ball abrasive obtained in step B into an oven at 80°C to dry to obtain the first dry powder;

Step D: pre-calcining; the dry powder obtained in step C is placed in an Al ₂ O ₃ crucible, and pre-fired for 4 hours under an atmospheric condition of 850° C. to obtain a pre-calcined powder;

Step E: ball milling; weighing 1% LiF and 1% V ₂ O ₅ in the calcined powder, and mixing LiF, V ₂ O ₅ with the obtained The calcined powder is placed together in a polytetrafluoroethylene ball mill tank for secondary ball milling, with absolute ethanol as the dispersant, and zirconia balls as the ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol is 1 : 5: 1.5, ball milled on a planetary ball mill for 12 hours to obtain the second ball mill material mixed uniformly;

Step F: drying; put the second ball mill obtained in step E into an oven at 80°C and dry to obtain a second dry powder;

Step G: granulation and compression molding; adding polyvinyl alcohol accounting for 8% by mass of the second dry powder to the dry powder obtained in step F to obtain pellets, and then grinding the pellets in an agate mortar, After the ground powder passes through a 100-mesh sieve, it is compressed into a cylindrical sample with a diameter of 12mm and a thickness of 6mm by 10MPa;

Step H: debinding and sintering; place the cylindrical sample obtained in step G in a muffle furnace, heat up according to the temperature curve of 2°C/min, keep it warm for 3 hours when the temperature reaches 550°C, and then proceed to debinding according to 2 °C/min temperature curve to raise the temperature, when the temperature rises to 900 °C, it is maintained at this temperature for 3 hours for sintering, and finally the Li ₂ MgSiO ₄ -based microwave dielectric ceramic material is obtained.

Example 2:

The invention discloses a low-temperature preparation method of low-medium microwave dielectric ceramics, which comprises the following steps:

Step A: batching; batching Li ₂ CO ₃ , ZnO, MgO, and SiO ₂ according to the general chemical formula Li ₂ (Mg _0.8 Zn _0.2 )SiO ₄ to form a mixture;

Step B: ball milling; put the mixture prepared in step A into a polytetrafluoroethylene ball milling tank, use absolute ethanol as a dispersant, and zirconia balls as a ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol 1: 5: 1.5, ball milled on a planetary ball mill for 12 hours; obtain the first ball mill that is uniformly mixed;

Step C: drying and sieving; putting the first ball abrasive obtained in step B into an oven at 80°C to dry to obtain the first dry powder;

Step D: pre-calcining; the dry powder obtained in step C is placed in an Al ₂ O ₃ crucible, and pre-fired for 4 hours under an atmospheric condition of 850° C. to obtain a pre-calcined powder;

Step E: ball milling; weighing 2% of LiF and 1% of V ₂ O ₅ in the calcined powder, and mixing LiF, V ₂ O ₅ with the obtained The calcined powder is placed together in a polytetrafluoroethylene ball mill tank for secondary ball milling, with absolute ethanol as the dispersant, and zirconia balls as the ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol is 1 : 5: 1.5, ball milled on a planetary ball mill for 12 hours to obtain the second ball mill material mixed uniformly;

Step F: drying; put the second ball mill obtained in step E into an oven at 80°C and dry to obtain a second dry powder;

Step G: granulation and compression molding; adding polyvinyl alcohol accounting for 8% by mass of the second dry powder to the dry powder obtained in step F to obtain pellets, and then grinding the pellets in an agate mortar, After the ground powder passes through a 100-mesh sieve, it is compressed into a cylindrical sample with a diameter of 12mm and a thickness of 6mm by 10MPa;

Step H: debinding and sintering; place the cylindrical sample obtained in step G in a muffle furnace, heat up according to the temperature curve of 2°C/min, keep it warm for 3 hours when the temperature reaches 550°C, and then proceed to debinding according to 2 °C/min temperature curve to raise the temperature, when the temperature rises to 900 °C, it is maintained at this temperature for 3 hours for sintering, and finally the Li ₂ MgSiO ₄ -based microwave dielectric ceramic material is obtained.

Example 3:

The invention discloses a low-temperature preparation method of low-medium microwave dielectric ceramics, which comprises the following steps:

Step A: batching; batching Li ₂ CO ₃ , ZnO, MgO, and SiO ₂ according to the general chemical formula Li ₂ (Mg _0.8 Zn _0.2 )SiO ₄ to form a mixture;

Step B: ball milling; put the mixture prepared in step A into a polytetrafluoroethylene ball milling tank, use absolute ethanol as a dispersant, and zirconia balls as a ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol 1: 3: 2, ball milled on a planetary ball mill for 6 hours; obtain the first ball mill that is uniformly mixed;

Step C: drying and sieving; putting the first ball abrasive obtained in step B into an oven at 80°C to dry to obtain the first dry powder;

Step D: pre-calcining; the dry powder obtained in step C is placed in an Al ₂ O ₃ crucible, and pre-fired for 4 hours under an atmospheric condition of 850° C. to obtain a pre-calcined powder;

Step E: ball milling; weighing 2% of LiF and 2% of V ₂ O ₅ in the calcined powder, mixing LiF, V ₂ O ₅ with the obtained in step D The calcined powder is placed together in a polytetrafluoroethylene ball mill tank for secondary ball milling, with absolute ethanol as the dispersant, and zirconia balls as the ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol is 1 : 3: 2, ball milled on a planetary ball mill for 8 hours to obtain the second ball mill material mixed uniformly;

Step F: drying; put the second ball mill obtained in step E into an oven at 80°C and dry to obtain a second dry powder;

Step G: granulation and compression molding; adding polyvinyl alcohol accounting for 8% by mass of the second dry powder to the dry powder obtained in step F to obtain pellets, and then grinding the pellets in an agate mortar, After the ground powder passes through a 100-mesh sieve, it is compressed into a cylindrical sample with a diameter of 12mm and a thickness of 6mm by 10MPa;

Step H: debinding and sintering; place the cylindrical sample obtained in step G in a muffle furnace, heat up according to the temperature curve of 2°C/min, keep it warm for 3 hours when the temperature reaches 550°C, and then proceed to debinding according to 2 °C/min temperature curve to raise the temperature, when the temperature rises to 900 °C, it is maintained at this temperature for 3 hours for sintering, and finally the Li ₂ MgSiO ₄ -based microwave dielectric ceramic material is obtained.

Example 4:

The invention discloses a low-temperature preparation method of low-medium microwave dielectric ceramics, which comprises the following steps:

Step A: batching; batching Li ₂ CO ₃ , ZnO, MgO, and SiO ₂ according to the general chemical formula Li ₂ (Mg _0.5 Zn _0.5 )SiO ₄ to form a mixture;

Step B: ball milling; put the mixture prepared in step A into a polytetrafluoroethylene ball milling tank, use absolute ethanol as a dispersant, and zirconia balls as a ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol 1: 4: 3, ball milled on a planetary ball mill for 14 hours; obtain the first ball mill that is uniformly mixed;

Step C: drying and sieving; putting the first ball abrasive obtained in step B into an oven at 80°C to dry to obtain the first dry powder;

Step D: pre-calcining; the dry powder obtained in step C is placed in an Al ₂ O ₃ crucible, and pre-fired for 4 hours under an atmospheric condition of 850° C. to obtain a pre-calcined powder;

Step E: ball milling; weighing 2% LiF and 3% Bi ₂ O ₃ in the mass percentage of the calcined powder, mixing LiF, Bi ₂ O ₃ with the obtained The calcined powder is placed together in a polytetrafluoroethylene ball mill tank for secondary ball milling, with absolute ethanol as the dispersant, and zirconia balls as the ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol is 1 : 4: 3, ball milled on a planetary ball mill for 16 hours, to obtain the second ball mill material mixed uniformly;

Step F: drying; put the second ball mill obtained in step E into an oven at 80°C and dry to obtain a second dry powder;

Step G: granulation and compression molding; adding polyvinyl alcohol accounting for 8% by mass of the second dry powder to the dry powder obtained in step F to obtain pellets, and then grinding the pellets in an agate mortar, After the ground powder passes through a 100-mesh sieve, it is compressed into a cylindrical sample with a diameter of 12mm and a thickness of 6mm by 10MPa;

Step H: debinding and sintering; place the cylindrical sample obtained in step G in a muffle furnace, heat up according to the temperature curve of 2°C/min, keep it warm for 3 hours when the temperature reaches 550°C, and then proceed to debinding according to 2 °C/min temperature curve to raise the temperature, when the temperature rises to 900 °C, it is maintained at this temperature for 3 hours for sintering, and finally the Li ₂ MgSiO ₄ -based microwave dielectric ceramic material is obtained.

Example 5:

The invention discloses a low-temperature preparation method of low-medium microwave dielectric ceramics, which comprises the following steps:

Step A: batching; batching Li ₂ CO ₃ , ZnO, MgO, and SiO ₂ according to the general chemical formula Li ₂ (Mg _0.5 Zn _0.5 )SiO ₄ to form a mixture;

Step B: ball milling; put the mixture prepared in step A into a polytetrafluoroethylene ball milling tank, use absolute ethanol as a dispersant, and zirconia balls as a ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol 1: 5: 1.5, ball milled on a planetary ball mill for 12 hours; obtain the first ball mill that is uniformly mixed;

Step C: drying and sieving; putting the first ball abrasive obtained in step B into an oven at 80°C to dry to obtain the first dry powder;

Step D: pre-calcining; the dry powder obtained in step C is placed in an Al ₂ O ₃ crucible, and pre-fired for 4 hours under an atmospheric condition of 850° C. to obtain a pre-calcined powder;

Step E: ball milling; weighing 3% LiF and 3% Bi ₂ O ₃ in the mass percentage of the calcined powder, and mixing LiF, Bi ₂ O ₃ with the obtained The calcined powder is placed together in a polytetrafluoroethylene ball mill tank for secondary ball milling, with absolute ethanol as the dispersant, and zirconia balls as the ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol is 1 : 5: 1.5, ball milled on a planetary ball mill for 12 hours to obtain the second ball mill material mixed uniformly;

Step F: drying; put the second ball mill obtained in step E into an oven at 80°C and dry to obtain a second dry powder;

Step G: granulation and compression molding; adding polyvinyl alcohol accounting for 8% by mass of the second dry powder to the dry powder obtained in step F to obtain pellets, and then grinding the pellets in an agate mortar, After the ground powder passes through a 100-mesh sieve, it is compressed into a cylindrical sample with a diameter of 12mm and a thickness of 6mm by 10MPa;

Step H: debinding and sintering; place the cylindrical sample obtained in step G in a muffle furnace, heat up according to the temperature curve of 2°C/min, keep it warm for 3 hours when the temperature reaches 550°C, and then proceed to debinding according to 2 °C/min temperature curve to raise the temperature, when the temperature rises to 900 °C, it is maintained at this temperature for 3 hours for sintering, and finally the Li ₂ MgSiO ₄ -based microwave dielectric ceramic material is obtained.

Embodiment 6:

The invention discloses a low-temperature preparation method of low-medium microwave dielectric ceramics, which comprises the following steps:

Step A: batching; batching Li ₂ CO ₃ , ZnO, MgO, and SiO ₂ according to the general chemical formula Li ₂ (Mg _0.5 Zn _0.5 )SiO ₄ to form a mixture;

Step B: ball milling; put the mixture prepared in step A into a polytetrafluoroethylene ball milling tank, use absolute ethanol as a dispersant, and zirconia balls as a ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol 1: 5: 1.5, ball milled on a planetary ball mill for 12 hours; obtain the first ball mill that is uniformly mixed;

Step C: drying and sieving; putting the first ball abrasive obtained in step B into an oven at 80°C to dry to obtain the first dry powder;

Step D: pre-calcining; the dry powder obtained in step C is placed in an Al ₂ O ₃ crucible, and pre-fired for 4 hours under an atmospheric condition of 850° C. to obtain a pre-calcined powder;

Step E: ball milling; weighing 4% LiF and 3% Bi ₂ O ₃ of the calcined powder by weighing the calcined powder and combining LiF, Bi ₂ O ₃ with the calcined The burnt powder is placed in a polytetrafluoroethylene ball mill jar for secondary ball milling, with absolute ethanol as the dispersant, and zirconia balls as the ball milling medium, wherein: the mass ratio of mixture: grinding balls: absolute ethanol is 1: 5: 1.5, ball milled on a planetary ball mill for 12 hours to obtain a second ball mill that is uniformly mixed;

Step F: drying; put the second ball mill obtained in step E into an oven at 80°C and dry to obtain a second dry powder;

Step G: granulation and compression molding; adding polyvinyl alcohol accounting for 8% by mass of the second dry powder to the dry powder obtained in step F to obtain pellets, and then grinding the pellets in an agate mortar, After the ground powder passes through a 100-mesh sieve, it is compressed into a cylindrical sample with a diameter of 12mm and a thickness of 6mm by 10MPa;

Step H: debinding and sintering; place the cylindrical sample obtained in step G in a muffle furnace, heat up according to the temperature curve of 2°C/min, keep it warm for 3 hours when the temperature reaches 550°C, and then proceed to debinding according to 2 °C/min temperature curve to raise the temperature, when the temperature rises to 900 °C, it is maintained at this temperature for 3 hours for sintering, and finally the Li ₂ MgSiO ₄ -based microwave dielectric ceramic material is obtained.

The ceramic samples obtained by sintering according to the experimental conditions of the above-mentioned specific examples are surface-treated with sandpaper or a polishing machine to obtain dense, smooth and flat ceramic samples. In this embodiment, SiC fine sandpaper is used for polishing, and then various analysis test. In this embodiment, the Archimedes drainage method is used to measure the density; the X-ray diffractometer is used to analyze the phase composition of the sample, and the main parameters of the test are: Cu target, Kα1 radiation Step scanning, step length 0.03 °, speed 3.6 °/min, scanning voltage 40KV, scanning range 15 ° ~ 70 ° (2θ), the test temperature of all samples is room temperature 20 ° C; this embodiment uses a scanning electron microscope to detect The surface micro-topography of the ceramic sample is observed; the present embodiment measures the microwave dielectric properties (dielectric constant, dielectric loss, resonant frequency temperature coefficient) by the principle of parallel plate resonance test;

The performance parameters of the Li ₂ (Mg _1-x Zn _x )SiO ₄ ceramic material prepared in Examples 1 to 6 are given below:

Fig. 1 is the XRD spectrum of the Li ₂ (Mg _0.5 Zn _0.5 ) SiO ₄ ceramics obtained in Example 6. It can be seen from Fig. 1 that the obtained Li ₂ (Mg _0.5 Zn _0.5 ) SiO ₄ ceramics are Li ₂ MgSiO ₄ phase and Li ₂ ZnSiO ₄ -phase coexistence structure.

Figure 2 (a), (b) and (c) are the SEM images of Li ₂ (Mg _0.8 Zn _0.2 ) SiO ₄ ceramics obtained in Example 1, Example 2 and Example 3, respectively. It can be seen from the figure that the particle size is not uniform , and there are voids on the grains, which is caused by Li ⁺ volatilization; Figure 2(d), (e) and (f) are Li ₂ (Mg _0.5 Zn _0.5 )SiO obtained in Example 4, Example 5 and Example 6, respectively ₄ The SEM picture of ceramics, it can be seen from the figure that with the increase of LiF content in the composite sintering aid, the particle size becomes more uniform and the arrangement becomes closer.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, and those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The above examples are for illustration rather than further limitation, and those skilled in the art can completely combine more specific implementation modes that can achieve the technical effects of the present invention within the scope of the technical solutions outlined in the summary of the invention. Therefore, all equivalent modifications or changes made by any person familiar with the technology without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (8)

1. a kind of low temperature preparation method of low dielectric microwave media ceramic, it is characterised in that comprise the following steps：

Step A：Dispensing；By Li₂CO₃、ZnO、MgO、SiO₂According to chemical general formula Li₂(Mg_1-xZn_x)SiO₄Progress dispensing forms mixed Compound, the chemical general formula Li₂(Mg_1-xZn_x)SiO₄Middle x span is 0 ＜ x≤0.5；

Step B：Ball milling；The first well mixed ball milling material is obtained after mixture obtained by step A is carried out into ball milling；

Step C：Drying, sieving；Sieving after first ball milling material drying obtained by step B is obtained into the first drying powder；

Step D：Pre-burning；First that step C is obtained dries powder pre-burning under atmospheric atmosphere, obtains pre-burning powder；

Step E：Ball milling；Pre-burning powder obtained by step D and LiF and low melting point oxide are subjected to secondary ball milling in the lump, it is described low Refractory oxides are Bi₂O₃Or V₂O₅；Wherein：The mass percent that LiF accounts for pre-burning powder is 1~4%, low melting point oxide The mass percent for accounting for pre-burning powder is 1~3%, obtains the second well mixed ball milling material；

Step F：Drying；The second ball milling material obtained by step E is dried to obtain the second drying powder；

Step G：Sintering；The second drying powder that step F is obtained is sintered under atmospheric atmosphere, and Li is finally made₂MgSiO₄ Base microwave medium ceramic material.

A kind of 2. low temperature preparation method of low dielectric microwave media ceramic according to claim 1, it is characterised in that the step Mechanical milling process is specially in rapid B：Using absolute ethyl alcohol as dispersant, using zirconia ball as ball-milling medium, according to mixture：Mill Ball：The mass ratio of absolute ethyl alcohol is ground for 1: 3~5: 1.5~3, and milling time is 6~16 hours, is obtained well mixed Ball milling material.

A kind of 3. low temperature preparation method of low dielectric microwave media ceramic according to claim 1, it is characterised in that the step Drying temperature is 70~100 DEG C in rapid C.

A kind of 4. low temperature preparation method of low dielectric microwave media ceramic according to claim 1, it is characterised in that the step Calcined temperature is 800~1000 DEG C in rapid D, and burn-in time is 2~6 hours.

A kind of 5. low temperature preparation method of low dielectric microwave media ceramic according to claim 1, it is characterised in that the step Specific mechanical milling process is in rapid E：Using absolute ethyl alcohol as dispersant, using zirconia ball as ball-milling medium, according to mixture：Mill Ball：The mass ratio of deionized water is ground for 1: 3~5: 1.5~3, and milling time is 12 hours, obtains well mixed ball Abrasive material.

A kind of 6. low temperature preparation method of low dielectric microwave media ceramic according to claim 1, it is characterised in that the step Drying temperature is 70~100 DEG C in rapid F.

A kind of 7. low temperature preparation method of low dielectric microwave media ceramic according to claim 1, it is characterised in that the step Sintering temperature is 850~950 DEG C in rapid H, and sintering time is 2~6 hours.

A kind of 8. low temperature preparation method of low dielectric microwave media ceramic according to claim 1, it is characterised in that the step Heating rate is 2 DEG C/min in dumping, sintering process in rapid H.