KR20180111053A - Dielectric Ceramics for Resonator Surports and the manufacturing method of the same - Google Patents

Abstract

The present invention relates to a dielectric ceramic material for a support of a resonator and a filter used in a wireless communication system and a manufacturing method thereof. The present invention provides a Zn_1.9-xM_xSi_1.05O_4 ceramic material composition having uniform sintering properties and dielectric properties in a high frequency band. As described above, according to the present invention, not only high dielectric properties can be obtained, but also an effect of realizing uniform and reproducible sintering properties and dielectric properties can be expected.

Description

TECHNICAL FIELD [0001] The present invention relates to a dielectric ceramic material for a resonator,

The present invention relates to a dielectric ceramic material for a resonator and a filter support used in a wireless communication system, and a method of manufacturing the same, and more particularly, to a Zn _{1 .9- x} M _x Si _{1 . 05} O ₄ ceramic material composition.

In recent years, as the amount of information is rapidly increased due to the development of wireless communication, and the communication frequency band is saturated, the frequency band used is increasing to a higher band, and there is a desperate need for a high-quality high frequency transmitting and receiving part. Therefore, the higher the frequency band, the lower the dielectric constant ( _r ) and the higher the quality factor (Q x f).

Meanwhile, a cavity filter used in a satellite relay or a wireless communication relay system in a microwave region is composed of a ceramic dielectric resonator and a ceramic support member for supporting the ceramic dielectric resonator in a metal material cavity as shown in FIG. Here, the ceramic support is required to have a low dielectric constant and a high quality factor dielectric property, and for this purpose, alumina (Al ₂ O ₃ ) is generally used. However, it is also possible to use other ceramic materials such as Mg ₂ SiO ₄ modified as disclosed in Korean Patent Registration No. 10-1261098 (Feb.

On the other hand, Zn _{1 . 9} Si _{1 . 05} O ₄ has a willemite crystal structure as shown in the prior art document 1 and exhibits excellent high frequency dielectric properties of about ε _r = 6.43 and Q × f = 120,000 GHz.

Further, Zn _{1 . 9} Si _{1 . 05} O ₄ By high-frequency dielectric ceramic is sintered prior art document 3 Zn _1.8 SiO _3.8 by adjusting the composition ratio of zinc (Zn) and silicon (Si) as disclosed in (Republic of Korea Patent No. 10-0842855 call) in 1300 ℃, ε _r = 6.6, Q x f = 127,000 GHz, and? _F = -20 ppm / ° C.

Also, according to the prior art document 4 (Korean Patent Laid-Open No. 10-2010-0098232), Zn _{1 . 8} SiO _{3 .8} The composition of vanadium oxide (V ₂ O ₅₎ or a bismuth oxide (Bi ₂ O ₃₎ by a sintering at 900 ℃ by addition of an appropriate _{amount, ε r = 7.3, Q ×} f = 17,500 GHz, τ f = -28 ppm / DEG C to improve dielectric characteristics.

According to the prior art document 5 (Korean Patent Registration No. 10-1261098), the modified Mg ₂ SiO ₄ is sintered at 1310 ° C to have a composition of ∈ _r = 10 or less, Q × f = 15,000 GHz, τ _f = 8 ppm / Lt; RTI ID = 0.0 > C < / RTI >

However, due to the various compounds added to the prior art, the dielectric properties for the supports of the resonator and the filter are insufficient. Particularly, there is a problem that the added materials cause the second phase to significantly deteriorate the quality factor of the dielectric properties.

 Therefore, the dielectric ceramics for the resonator and the filter support used in the radio communication system for high-quality high-frequency transmission and reception have a dielectric constant and a quality factor such that the shrinkage ratio does not affect the sintering property and the resonator characteristics, It is very important to have uniform dielectric properties.

The dielectric ceramics used in duplexer, DMB / DAB, satellite LNB, oscillator, repeater, and bandpass filter (BPF) in the frequency band of tens of GHz will be a high frequency dielectric ceramic For the high-frequency transmission and reception with the resonator, the dielectric constant (ε _r ) is low and the quality factor (Q × f) is required to have higher dielectric properties.

Journal of the Korean Institute of Electrical and Electronic Material Engineers, Vol. 38, No. 7, pp428. Korean Patent Registration No. 10-1261098 (2013.05.02.) Korean Patent Registration No. 10-0842855 (Jun. 25, 2008) Korean Patent Publication No. 10-2010-0098232 (2010.09.05.)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dielectric ceramic material for a resonator support having uniform sintering property and dielectric property in a high frequency band and a manufacturing method thereof.

Dielectric ceramics for supporting resonators and filters used in radio communication systems for high-quality high-frequency transmission and reception have an influence on the sinterability and resonator characteristics with a constant shrinkage ratio so that there is no difference in size after sintering, It is important that the dielectric constant and the quality factor have uniform dielectric properties so that the sinterability and dielectric properties of the Zn _{1 .9-x} M _x Si _1.05 O ₄ system high-frequency dielectric ceramic materials are improved by adding elements or additives Therefore, it is essential to use high-purity raw materials for this purpose, and it is also important to select suitable additives in consideration of the size and valence of substitution elements and to add appropriate amounts. In short, the present invention has a significance in that sintering property and dielectric property are uniform while maintaining the dielectric property as much as possible.

In order to achieve the above object, the present invention provides a dielectric material for a resonator support, characterized in that M is a +2 metal and x is 0.05 to 0.4 in the formula Zn _1.9-x M _x Si _1.05 O ₄ , Ceramic material.

The M is preferably at least one selected from the group consisting of magnesium (Mg), nickel (Ni), cobalt (Co), and manganese (Mn).

The ceramic material is preferably manufactured by sintering at a temperature in the range of 1325 ° C to 1400 ° C.

As described above, according to the present invention, high dielectric characteristics can be obtained in a high frequency band, and uniform and reproducible sintering properties and dielectric characteristics can be realized. Particularly, the present invention suppresses the formation of the second phase and prevents the deterioration of the quality factor by substituting a certain amount of Mg, Ni or the like for Zn sites.

Further, the present invention can obtain a uniform dielectric property and shrinkage ratio over a wide sintering temperature range, so that the effect of process improvement can be expected.

In addition, the present invention can expect high-frequency high-frequency transmission and reception in the frequency band of tens GHz.

Fig. 1 shows the structure of a general cavity filter.
2 is M _x Zn _{1 .9- 0} in accordance with one embodiment of the present _{invention. 1} Si _{1 . 05} O ₄ based dielectric ceramics according to the sintering temperature.
3 is Zn, according to one embodiment of the present invention _{1 .9- x} M _{0. 1} Si _{1 . 05} O ₄ based dielectric ceramic material according to sintering temperature.
4 is a Zn _{1 .9-} M _{x 0,} according to one embodiment of the present _{invention. 1} Si _{1 . 05} O ₄ based dielectric ceramic material according to sintering temperature.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the present invention, the defined terms are defined in consideration of the functions of the present invention, and they may be changed according to the intention or custom of the technician working in the field, and the definition is based on the contents throughout this specification It should be reduced.

In order to solve the above-described problems, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a method of manufacturing a Zn _1.9-x M _x Si _1.05 O ₄ excellent in high frequency dielectric property, Mn and the like are partially substituted and added so as to have a stable sintering property and dielectric property. The dielectric ceramic composition of the present invention is represented by the following formula: Zn _{1 .9-x} M _x Si _1.05 O ₄ , M is the above-listed elements, and x is added so as to satisfy 0.05 to 0.4.

The composition of the present invention can be prepared by the following process.

The composition of the present invention is composed of ZnO, MgO, NiO, Co ₂ O ₃ (manufactured by Kojundo Chem. Lab. Co., Ltd.) having a purity of 99% And the SiO ₂ was used as the starting material.

Zn _{1 .9 - x} M _x Si ₁ with uniform sinterability and dielectric properties _{. 05} O ₄ -based dielectric ceramics were weighed into raw material powders corresponding to each composition as shown in the following Table 1, and then put into a polyethylene container together with zirconia balls and ethyl alcohol and mixed for 24 hours.

After drying, the mixed powder was put into a metal mold having a diameter of 25 mm, uniaxially pressed, and then calcined at 1100 ° C for 10 hours. The calcined shaped body was again ball milled by the above mixing method, and then placed in an oven and dried at 110 to 120 ° C for 24 to 48 hours.

After drying, the calcined powder was placed in a metal mold having a diameter of 15 mm, uniaxially pressed at a pressure of 50 MPa, and then sintered at a temperature of 1325 to 1400 ° C for 2 hours at a rate of 5 ° C / min .

The quality factor (Q x f) of the high-frequency dielectric properties was measured by X-ray diffraction analysis (D / MAX-2500V / PC, Rigaku, Japan) for the powder obtained by measuring the linear shrinkage of the sintered body, And the temperature coefficient (τ _f ) were measured by the cavity method and the dielectric constants were measured by the Hakki-Coleman method using the Network Analyzer, respectively.

The temperature coefficient was measured using the model R3767CG (Advantest, Japan) and the quality factor and dielectric constant were measured using the model E5071C (Keysight, U.S.A.).

Hereinafter, the constitution and effects of the present invention will be described in more detail through examples. These embodiments are only for illustrating the present invention, and the scope of the present invention is not limited by these embodiments.

<Examples>

Examples of the preparation method for preparing the composition of the present invention are as described above.

In the present invention, Zn _{1 . 9} Si _{1 . 05} O ₄ , it was possible to secure uniformity of sintering property and dielectric property by replacing part of Zn with +2 metal, and the content was 0.05 to 0.4 mol. If outside the lower limit of the above range becomes large over the change in the sintering shrinkage and changes in the dielectric properties, if is outside the upper limit, the Zn _{1. 9} Si _{1 . 05} O ₄ , the numerical value has its critical significance in the above range.

<Comparative Example>

In order to investigate the substitution effect of the +2 metal element in the present invention, Zn _{1 . 9} Si _{1 . 05} O ₄ specimens were prepared and evaluated for their properties in the same manner as in the above examples.

Zn _{1 .9 - x} M _x Si _{1 . 05} Sinterability and Dielectric Properties of O ₄ Dielectric Ceramics number       Composition (mol) Sintering temperature (℃) Shrinkage (%) ε _r Q x f (GHz) Remarks ZnO M ₂ O ₃ SiO ₂ Comparative Example 1 1.9 - 0 1.05 1325 20.60 6.08 107857 Comparative Example 2 1.9 - 0 1.05 1350 21.47 6.07 118871 Comparative Example 3 1.9 - 0 1.05 1375 21.80 6.21 127409 Comparative Example 4 1.9 - 0 1.05 1400 22.13 6.39 129435 Example 1 1.8 Mg 0.1 1.05 1325 22.80 6.31 122791 Example 2 1.8 Mg 0.1 1.05 1350 22.67 6.33 126957 Example 3 1.8 Mg 0.1 1.05 1375 22.67 6.3 126156 Example 4 1.8 Mg 0.1 1.05 1400 22.80 6.37 129019 Example 5 1.8 Ni 0.1 1.05 1325 22.80 6.41 123679 Example 6 1.8 Ni 0.1 1.05 1350 22.93 6.45 129850 Example 7 1.8 Ni 0.1 1.05 1375 22.67 6.39 130529 Example 8 1.8 Ni 0.1 1.05 1400 22.73 6.4 128527 Example 9 1.8 Co 0.1 1.05 1325 22.07 6.4 128612 Example 10 1.8 Co 0.1 1.05 1350 22.67 6.4 128970 Example 11 1.8 Co 0.1 1.05 1375 22.27 6.38 126139 Example 12 1.8 Co 0.1 1.05 1400 22.07 6.48 124954 Example 13 1.85 Mg 0.05 1.05 1350 22.33 6.43 123845 Example 14 1.7 Mg 0.2 1.05 1350 22.53 6.35 121925 Example 15 1.5 Mg 0.4 1.05 1350 23.00 6.33 123202 Example 16 1.85 Ni 0.05 1.05 1350 23.20 6.43 122776 Example 17 1.7 Ni 0.2 1.05 1350 23.20 6.46 129318 Example 18 1.5 Ni 0.4 1.05 1350 23.73 6.48 122810 Example 19 1.85 Co 0.05 1.05 1350 23.00 6.49 122066 Example 20 1.85 Mn 0.05 1.05 1350 23.53 6.45 120026

Zn _{1 .9 - x} M _x Si ₁ with uniform sinterability and dielectric properties _. As shown in Table 1 and Fig. 2, the shrinkage of ₀₅ O ₄ -based dielectric ceramics showed a sufficient sintering shrinkage of 22% to 23% except for Example 21, although there was a slight difference depending on the substitution amount of +2 metal element And the change of the shrinkage ratio according to the sintering temperature is not large. However, in the case where +2 is not substituted for the metal element, sintering shrinkage occurs well, but the shrinkage ratio varies greatly depending on the sintering temperature, so that it is difficult to produce a support having a uniform size and a post-process such as a polishing process is inevitable A problem was found.

On the other hand, Zn _{1 .9 - x} M _x Si _{1 . The} dielectric constant of ₀₅ O ₄ dielectric ceramics is about 6.3-6.5 when the metal element is replaced with a dielectric constant of +2 and the quality factor is 120,000 GHz or more in most compositions depending on the sintering temperature And the width of the change is very small. However, when the metal element is not substituted, the change of the dielectric property depending on the sintering temperature is very high. When the metal element is not substituted, the resonance characteristics are affected when the metal element is used as a support of the resonator, thereby deteriorating the characteristics of the radio communication system for high- .

From the above results, Zn _{1 .9 - x} M _x Si ₁ with uniform sinterability and dielectric properties _{. In} order to manufacture ₀₅ O ₄ -based dielectric ceramics, it is very important to select a suitable +2-valent metal element and replace it in an appropriate amount. According to the present invention, magnesium (Mg), nickel (Ni), and cobalt Co) is substituted in the range of 0.05 to 0.4, it is possible to manufacture a dielectric ceramic material excellent in sintering property and dielectric property for a resonator support.

Claims (3)

Zn _{1 .9 - x} M _x Si _{1 . 05} O ₄ , M is a +2 metal, and x is 0.05 to 0.4. The method according to claim 1,
Wherein the M is at least one selected from the group consisting of magnesium (Mg), nickel (Ni), cobalt (Co), and manganese (Mn). The method according to claim 1,
Wherein the ceramic material is manufactured by sintering in a range of 1325 ° C to 1400 ° C.

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