JPH04209759A - Dielectric porcelain for high frequency - Google Patents

Abstract

PURPOSE:To increase the range of dielectric constant, raise a Q value, reduce and stabilize the temperature coefficient and provide high performance of IC substrates for microwaves using the resultant composition by providing the aforementioned composition, expressed by the general formula and further including Mn2O3 therein. CONSTITUTION:The aforementioned dielectric porcelain for high frequency is formed from a composition, expressed by the general formula [(x) is 0.42-0.54; (y) is 0.06-0.18; (z) is 0.4; (m) is 0.05-0.7; (n) is 0-1; (x+y) is 0.61 and prepared by further adding <=3wt.% (based on the total amount) Mn2O3 thereto. The above-mentioned general formula is expressed by xSrO.yCaO.z[(1-m)TiO2.m/2{TaO5/2.(1-n)GaO3/2.nGdO3/2}]. The aforementioned porcelain has a wide range of dielectric constant, further, a high Q value and a low stabilized temperature coefficient.

Description

[Detailed description of the invention]

[00013

[Industrial Application Field] When used in the microwave frequency range, the present invention exhibits an extremely wide range of dielectric constants with the same composition, and achieves a practically sufficient Q value and small and stable temperature characteristics. This invention relates to high frequency dielectric ceramics. [0002] [0002] High frequency dielectric ceramics are widely applied as resonators, filters, substrates, etc. in mobile radio, satellite broadcasting, microwave integrated circuits, etc., and are used to improve filter characteristics, frequency stability, and This has greatly contributed to the miniaturization of devices and circuits. Devices using such dielectric materials are used at various frequencies, and the required dielectric constant changes depending on the frequency used. Also,
Dielectric properties required differ depending on the type of device or its format. Therefore, when designing a wide variety of dielectric devices, it is important to consider the existence of materials with similar electrical, physical, or chemical stability such as insulation resistance, mechanical strength, and water absorption, but with different dielectric properties. This is extremely advantageous since there are fewer changes in design factors. Desirable properties for such dielectrics include: ■ having a relative dielectric constant over a wide range; ■ having similar properties other than dielectric properties; ■ exhibiting low dielectric loss; ■
One example is that the temperature stability of the resonance frequency is excellent. [0003] In order to satisfy the above-mentioned characteristics, especially the characteristic shown in (2), it is thought that it is necessary that the basic compositions be similar, but it has not been possible to find a dielectric material having such characteristics so far. Dielectric materials that have similar basic compositions and can be used at high frequencies include, for example, Reference J, of A
1. Ceram, Soc, 58[9-10], 4
18 (1975) BaT! A, Ba2Ti9
Examples include O20 (BaTiq50+o). [0004]

[Problem to be Solved by the Invention] Generally speaking, high-frequency dielectric ceramic materials have a wide range of dielectric constants, with the same basic composition (similar properties other than dielectric properties),
It is extremely difficult to simultaneously achieve low dielectric loss and a small and stable temperature coefficient. That is, the relative permittivity of both of the conventional dielectric ceramics mentioned above is about 40,
The relative dielectric constant range that can be covered with similar basic compositions is extremely small. [00051 The present invention has been made to solve such problems, and while maintaining a similar basic composition, it exhibits a wide dielectric constant ranging from 20 to 60 in the microwave front region, and has a sufficiently high Q value for practical use. The aim is to create high-frequency dielectric ceramics that have a stable and small temperature coefficient and facilitate device development. [0006]

[Means for Solving the Problems] The high frequency dielectric ceramic of the present invention has the general formula: xSrO-yCaO-z[(1-m)TiOz
-m/2(TaOs2- (1n) Ga03z2
*nGdo3. z)] where 0.42≦x≦0.
54 (or 0.06≦x≦0.18) 0.06≦y≦
0.18 (or 0.42≦y≦0.54) Z =0.
40 0.05≦m≦0.70 0.00≦n≦1. OO x+y =0.6, and Mn2O3 is further added in an amount of 3% by weight or less based on the total amount. [0007]

[Operation] By using the composition described above, the present invention provides
It is possible to achieve the intended purpose. [0008]

EXAMPLES The present invention will be explained below based on examples. [00091 The dielectric ceramic of the embodiment of the present invention is obtained by mixing and sintering, for example, strontium carbonate, calcium carbonate, titanium oxide, tantalum oxide, gallium oxide, gadolinium oxide, and manganese oxide in a predetermined ratio, General formula: xsro-ycaO-7[(1-m)TiO2-
m/2 (Ta05g @ (1n) Ga03/2・n
Gd03/2)] where 0.42≦x≦0.54 (or 0.06≦x≦0.18) 0.06≦y≦0.18 (
or 0.42≦y≦o, 54) Z = 0.40 0.05≦m≦0.70 0.00≦n≦1.00 % or less. The limit amount is determined comprehensively for various reasons, and it is not easy to define it unambiguously.Also, it may differ depending on the processing conditions during manufacturing, etc., but basically it is as follows. can be shown. x outside the above composition range <0.06, x>
When the value becomes 0.54, a decrease in the Q value is observed. Also, 0.1
When 8<X<0.42, the relative permittivity increases, but both the Q value and the temperature coefficient of the relative permittivity deteriorate. Furthermore, if the value of m is outside the claimed range, the temperature coefficient of relative dielectric constant will deteriorate. In these composition ranges, dielectric properties deteriorate, making it difficult to use as an industrial material. Furthermore, although the temperature coefficient changes slightly to the positive side by adding Mn, adding more than 3% by weight causes a decrease in the Q value. [00101 Hereinafter, the present invention will be explained with reference to Examples and Comparative Examples. [00111 [Examples and Comparative Examples] Commercially available strontium carbonate, calcium carbonate, titanium oxide, tantalum oxide, gallium oxide, gadolinium oxide, and manganese oxide powders were weighed to have the compositions shown in Table 1, and zirconia balls were prepared. , and ethyl alcohol into a nylon ball mill bot and mixed for 16 hours. After that, this mixed mud was heated to 100℃.
After drying by evaporation for 3 hours and pulverizing, at 1100°C,
Calcination was performed for 3 hours to obtain a compound powder. Furthermore, this compound powder was pulverized in a ball mill under the same conditions as above,
Dry. The obtained powder is 700-800Kg/c
The molded body was molded into a cylindrical shape with a diameter of 16 mm and a height of 12 mm under a pressure of 1,400 m2 in an oxygen atmosphere.
Dielectric ceramics of examples of the present invention were obtained by sintering at ~1550°C for 4 hours. [0012] A dielectric ceramic of a comparative example was obtained in the same manner as in the example except that the sintering was performed in an air atmosphere. [0013] After machining each of the porcelains obtained in the above manner to a predetermined size, the dielectric properties (relative permittivity and Q value) were measured at 6GH7 using the dielectric resonator method, and the measurement results are shown in Table 1. show. Table 1 shows the relative permittivity, Q value, and
And the temperature coefficient of relative dielectric constant is shown. From Table 1, the dielectric ceramics of the examples of the present invention can be used in the microwave region as well.
Wide range of relative permittivity ranging from 20 to 60 units and sufficiently high Q
It can be seen that it has both a small and stable temperature coefficient. [0014]

[Table 1] (0015]

[Effects of the Invention] As explained above, the present invention has the following properties:
-m/2(TaO2,2・n)GaO372・nGd
03/2)] where 0.42≦x≦0.54 (or 0
．． 06≦x≦0.18) 0.06≦y≦0.18 (or 0.42≦y≦0.54)z =0.40 0.05≦m≦0.70 0, 00≦n≦1 .00 x+y = 0.6, and by adding and containing Mn2O3 at 3% by weight or less of the total amount, it has a wide range of relative permittivity ranging from 20 to 60 even in the microwave region, and is practical. High frequency dielectric ceramics having a sufficiently high Q value and a small and stable temperature coefficient can be obtained. For example, by using the dielectric ceramic of the present invention, the performance of microwave application parts such as microwave IC boards can be improved. Easy to design devices etc.

[Procedural amendment]

[Submission date] June 28, 1991

[Procedural amendment 1]

[Name of document to be amended] Specification

[Correction target item name] 0002 [Correction method] Change

[Correction details]

[0002]

[Prior Art] High-frequency dielectric ceramics are widely applied as resonators, filters, substrates, etc. in mobile radio, satellite broadcasting, microwave integrated circuits, etc., and are used to improve filter characteristics, frequency stability, and devices and circuits. This has greatly contributed to the miniaturization of the Devices using such dielectric materials are used at various frequencies, and the required dielectric constant changes depending on the frequency used. Also,
Dielectric properties required differ depending on the type of device or its format. Therefore, when designing a wide variety of dielectric devices, it is important to consider the existence of materials with similar electrical, physical, or chemical stability such as insulation resistance, mechanical strength, and water absorption, but with different dielectric properties. This is extremely advantageous since there are fewer changes in design factors. Desirable properties for such dielectrics include: ■ having a relative dielectric constant over a wide range; ■ having similar properties other than dielectric properties; ■ exhibiting low dielectric loss; and ■ Temperature stability of the resonant frequency. You can point out that the company is excellent.

[Procedural amendment 2]

[Name of document to be amended] Specification

[Correction target item name] 0009 [Correction method] Change

[Correction details]

[00091] The dielectric ceramic of the embodiment of the present invention is obtained by mixing and sintering, for example, strontium carbonate, calcium carbonate, titanium oxide, tantalum oxide, gallium oxide, gadolinium oxide, and manganese oxide in a predetermined ratio, General formula: xsro -ycaO・z[(1-m)TiO2
・m/2(TaO5/z @ (1-n) Gao3□
−nGdo++z:: )] where 0.42≦x≦
0.54 (or 0.06≦x≦0.18) 0.06
≦y≦0.18 (or 0.42≦y≦0.54) Z
=0.40 0.05≦m≦0.70 0
．． 00≦n≦1°00 x+y=0.6, and further contains Mn2O3 in an amount of 3% by weight or less based on the total amount. The limit amount is determined comprehensively for various reasons, and it is not easy to define it unambiguously.Also, it may differ depending on the processing conditions during manufacturing, etc., but basically it is as follows. can be shown. When x<0.06 and X>0.54 outside the above composition range, a decrease in Q value is observed. Also, 0.18<x<
When it becomes 0.42, the relative permittivity increases, but Q
Both the value and the temperature coefficient of dielectric constant deteriorate. Furthermore, if the value of m is outside the claimed range, the temperature coefficient of relative dielectric constant will deteriorate. In these composition ranges, dielectric properties deteriorate, making it difficult to use as an industrial material. Also, M
The temperature coefficient changes slightly to the positive side due to the addition of n, but 3
If added in excess of % by weight, the Q value will decrease.

[Procedural amendment 3]

[Name of document to be amended] Specification

[Correction target item name 10011 [Correction method] Change

[Correction details]

[00111 [Examples and Comparative Examples] Commercially available strontium carbonate, calcium carbonate, titanium oxide, tantalum oxide, gallium oxide, gadolinium oxide, and manganese oxide powders were weighed to have the compositions shown in Table 1, and zirconia poles were prepared. , and ethyl alcohol into a nylon ball mill bot and mixed for 16 hours. Thereafter, this mixed mud was dried by evaporation at 100° C. for 3 hours, crushed, and then calcined at 1100° C. for 3 hours to obtain a compound powder. Further, this compound powder was ground in a ball mill under the same conditions as described above and dried. The obtained powder was molded into a cylindrical shape with a diameter of 16 mm and a height of about 12 mm under a pressure of 700 to 800 Kg/cm2, and this molded body was heated at 1400 to 1550°C in an oxygen atmosphere.
By performing sintering for 4 hours, a dielectric ceramic according to an example of the present invention was obtained.

Claims (2)

[Claims] [Claim 1] General formula: xSrO・yCaO・z[(1-
m) TiO_2・m/2{TaO_5_/_2・(1-
n) GaO_3/2・nGdO_3_/_2}] where,
0.42≦x≦0.54 0.06≦y≦0.18 z=0.40 0.05≦m≦0.70 0.00≦n≦1.00 x+y=0.6 , and further contains Mn_2O_3 in an amount of 3% by weight or less of the total amount. [Claim 2] General formula: xSrO・yCaO・z[(1-
m) TiO_2・m/2{TaO_5_/_2・(1-n)GaO_3_/_2・nGdO_3_/_2
}] where 0.06≦x≦0.18 0.42≦y≦0.54 z=0.40 0.05≦m≦0.70 0.00≦n≦1.00 x+y=0. 6 and further contains Mn_2O_3 in an amount of 3% by weight or less based on the total amount.