JP3205029B2 - High frequency dielectric ceramic composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel high frequency dielectric ceramic composition.

[0002]

2. Description of the Related Art Dielectric ceramic compositions are used in dielectric resonators, MIC dielectric substrates, and the like in high-frequency regions such as microwaves and millimeter waves. Conventionally, as such a dielectric porcelain composition,
For example, _{Ba (Zn1 / 3, Ta2 /} 3) O 3 -Ba (Zn
1/3, Nb2 / 3) system of _{O 3} are well known, recently B
a (Zr _x , Zn _y , _{T az} ) O _{7 / 2-x / 2-3y / 2} or B
The system of _{a (Sn x Zn y Ta z} ) O 7/2-x / 2-3y / 2 have been developed (JP-58-45155,58-45156
No.).

Further, a dielectric ceramic composition in which the Ba composition ratio is less than the stoichiometric ratio has been proposed (Japanese Patent Laid-Open No. 2-5 / 1990).
No. 1464). This composition has the general formula Ba _1-x (Zn
It is represented by _{1 / 3Ta2 / 3) O 3} 0.004 ≦ x ≦ 0.0
It is manufactured by weighing so as to fall within the range of 1, pulverizing only by a dry method after calcining, and firing after molding at 1600 to 1700 ° C. for 1 to 10 hours. According to this method, a composition having a high Q value is obtained in a short time with little energy.

It is desired that the material used in the above-mentioned microwave dielectric resonator or the like can set the temperature coefficient (τ _f ) of the resonance frequency to an arbitrary value with good reproducibility while maintaining a high Q value. Recently, the frequency range to be used has been increasing, and shortage of the Q value has occurred.

Thus, the present invention solves the above-mentioned technical problems, and further has a high Q value usable in a high frequency range and a high frequency dielectric ceramic composition capable of setting the resonance frequency temperature range with good reproducibility. The purpose is to provide things.

[0006]

According to the research and experiments of the present inventors, Ba (Zn1 / 3 Ta2 / 3) which has been conventionally used is used.
A part of the O ₃ -based material is made of BaZrO ₃ -based material and BaSnO
_By substituting with a tertiary material and making the Ba composition ratio less than the stoichiometric ratio, the above object is achieved, the temperature coefficient of resonance frequency can be adjusted with good reproducibility, and a dielectric material having a high Q value can be obtained. The inventors have found that a body porcelain composition can be obtained, and arrived at the present invention.

Accordingly, the present invention relates to a compound of the general formula (1-xy) Ba _1-z (Zn1 / 3Ta2 / 3) O ₃ + x
Represented by _{Ba 1-z ZrO 3 + yBa} 1-z SnO 3, 0.002 ≦ x ≦ 0.05,0.002 ≦
An object of the present invention is to provide a dielectric ceramic composition for high frequencies, wherein y ≦ 0.08 and 0.005 ≦ z ≦ 0.050.

[0008] The porcelain composition of the present invention has the above composition, where the value of z is 0.005 ≦ z ≦
The reason for setting the range to 0.05 is that if z is 0.005 or less, sintering is difficult, and if z is 0.05 or more, cracks are likely to occur. Can be avoided.

In the present invention, as described above, Ba (Zn1 / 3
Ta2 / 3) substituted but is was replaced with BaZrO ₃ and BaSnO ₃ by BaZrO ₃ a part of the _{O 3} will result in an increase in the resonant frequency temperature coefficient _{(τ f), Ba 1-} z SnO
_{Since the} replacement by ₃ results in a decrease in the resonance frequency temperature coefficient and an improvement in the Q value, the replacement amount of the two, that is, the values of x and y in the above equation are optimized within the above range, thereby maintaining a high Q value. The temperature coefficient of the resonance frequency can be set to any suitable value, so that it can be used favorably even in the high frequency range that has been increasing in recent years.

FIG. 1 is a triangular chart showing the composition range of the ternary dielectric ceramic composition of the present invention having the above general formula.

[0011] Such a dielectric ceramic composition was manufactured by the following method, and the dielectric properties of the obtained composition were measured. High purity BaCO ₃ , ZnO, T as starting materials
Using a ₂ O ₅ , ZrO ₂ , and SnO ₂ , raw materials were weighed so as to have a composition represented by the above general formula. This was wet-mixed with pure water in a resin pot for 20 hours, dried, and calcined at 1300 ° C. for 10 hours. The obtained calcined product was pulverized in a mortar and granulated by adding a binder. This was molded into a disk having a diameter of 16 mm and a thickness of 9 mm under a pressure of 30 MPa. Next, the molded product is placed in the atmosphere for 1 hour.
It was fired at 600 ° C. for 40 hours to obtain a desired dielectric ceramic composition.

The upper and lower surfaces and side surfaces of a molded article of the obtained composition are each shaved by about 1 mm to prepare a sample for measurement. The sample has a relative dielectric constant ε _r , a dielectric loss Q _{o at} a resonance frequency of about 7 GHz, and a resonance loss. Frequency temperature coefficient τ _f (ppm /
° C) was measured by the post-resonator method.

Now, the relative dielectric constant Er, the dielectric loss Q, and the resonance frequency temperature coefficient τ _f (ppm / ° C.) of the ternary composition represented by the above general formula, which are made by changing the values of x and y while keeping z constant. Are measured, and changes in various dielectric properties due to changes in the composition are shown in FIGS. It will be apparent from these figures that the ternary dielectric ceramic composition according to the present invention has better dielectric properties than compositions outside the scope of the present invention.

[0014]

As described above, according to the present invention, Ba (Z
n1 / 3 Ta2 / 3) BaZrO 3 a part of the _{O 3} and BaSn
The dielectric porcelain composition replaced with an O ₃ -based material and having a Ba composition ratio less than the stoichiometry is set to an arbitrary value by well adjusting the resonance frequency temperature coefficient while maintaining a high Q value. It can be used well in the high frequency range and is really effective.

[Brief description of the drawings]

FIG. 1 is a triangular chart showing the composition range of the composition of the present invention.

FIG. 2 is a graph showing a change in relative dielectric constant (Er) according to a change in the composition of the composition of the present invention.

FIG. 3 is a graph showing a change in dielectric loss (Q).

FIG. 4 is a graph showing a change in the resonance frequency temperature coefficient (τ _f ).

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-45156 (JP, A) JP-A-2-199052 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01B 3/12 C04B 35/00

Claims (1)

(57) [Claims] 1. The formula (1-xy) Ba ₁ -z (Zn1 / 3 Ta2 / 3) O ₃ + x
Represented by _{Ba 1-z ZrO 3 + yBa} 1-z SnO 3, 0.002 ≦ x ≦ 0.05,0.002 ≦
A dielectric ceramic composition for high frequencies, wherein y ≦ 0.08 and 0.005 ≦ z ≦ 0.050.