JPH05225825A - Dielectric porcelain composition for high-frequency wave - Google Patents

Abstract

PURPOSE:To obtain a high Q-value which can be used in a high-frequency area, and to set a resonance frequency temperature coefficient in a good reproducibility. CONSTITUTION:The dielectric porcelain composition for high-frequency wave is shown as the general formula (1-x-y)Ba1-Z (Zn1/3 Ta2/3) O3+ xBa1-ZZrO3+yBa1-ZSnO3, in which the x, y, and z are within 0.002<=x<=0.05, 0.002<=y<=0.08, and 0.005<=z<=0.050.

Description

Detailed Description of the Invention

[0001]

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 for dielectric resonators, dielectric substrates for MICs, etc. in high frequency regions such as microwaves and millimeter waves. As such a dielectric ceramic composition, conventionally,
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 , Ta _z ) O _{7 / 2-x / 2-3y / 2} system and B
A system of a (Sn _x Zn _y Ta _z ) O _{7 / 2-x / 2-3y / 2} has been developed (JP-A-58-45155, 58-45156).
Publication).

Further, a dielectric ceramic composition having a Ba composition ratio lower than the stoichiometric ratio has also been proposed (Japanese Patent Laid-Open No. 2-5).
1464 publication). 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 it so as to be within the range of 1, and pulverizing only by a dry method after calcination, and after molding, firing at 1600 to 1700 ° C. for 1 to 10 hours. According to this method, a composition having a high Q value can be obtained with a small amount of energy in a short time.

As a material used in the above microwave dielectric resonator, it is desired that the temperature coefficient (τ _f ) of the resonance frequency can be set to an arbitrary value with good reproducibility while maintaining a high Q value. Recently, the frequency range to be used has become higher and the Q value has become insufficient.

Thus, the present invention solves the above technical problems, has a high Q value that can be used in a higher frequency range, and can set the resonance frequency temperature range with good reproducibility. It is intended to provide goods.

[0006]

According to the research and experiment by the present inventor, Ba (Zn1 / 3 Ta2 / 3), which has been conventionally used, is used.
A part of O ₃ -based material is BaZrO ₃ -based material and BaSnO
_By substituting with a ₃ system 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 the dielectric constant with a high Q value The present invention has been completed by finding that a body porcelain composition can be obtained.

[0007] Accordingly, the present invention is represented by the general formula (1-x-y) Ba 1-z (Zn1 / 3 Ta2 / 3) O 3 + x
It is represented by Ba _1-z ZrO ₃ + yBa _1-z SnO ₃ , and 0.002 ≦ x ≦ 0.05, 0.002 ≦
The present invention provides a dielectric ceramic composition for high frequency, characterized in that y ≦ 0.08 and 0.005 ≦ z ≦ 0.050.

The porcelain composition of the present invention has the composition as described above, and the value of z is 0.005≤z≤.
The reason why the range of 0.05 is set is that it is difficult to sinter when z is 0.005 or less, and cracks easily occur when z is 0.05 or more. Can be avoided.

In the present invention, as described above, Ba (Zn1 / 3
A part of Ta 2/3) O ₃ was replaced with BaZrO ₃ and BaSnO _3, but the replacement with BaZrO ₃ resulted in an increase in the resonance frequency temperature coefficient (τ _f ), and Ba _1-z SnO 3
_The replacement by ₃ brings about a reduction in the temperature coefficient of the resonance frequency and an improvement in the Q value. The temperature coefficient of the resonance frequency can be set to any suitable value, and the temperature coefficient of the resonance frequency can be favorably used even in the high frequency region which has been increasing in recent years.

The composition range of the ternary dielectric ceramic composition of the present invention having the above general formula is shown in a triangular diagram in FIG.

Such a dielectric ceramic composition was produced 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,} SnO 2, they were respectively weighed so that the composition represented by the general formula. This was wet mixed with pure water in a resin pot for 20 hours, dried, and then calcined at 1300 ° C. for 10 hours. The obtained calcined product was crushed in a mortar, a binder was added, and granulated. This was molded into a disc having a diameter of 16 mm and a thickness of 9 mm at a pressure of 30 MPa. Then, this molded product was placed in the atmosphere at 1
The target dielectric ceramic composition was obtained by firing at 600 ° C. for 40 hours.

The upper and lower surfaces and side surfaces of the obtained molded product of this composition were each ground by about 1 mm to prepare a sample for measurement, and the relative permittivity ε _r , dielectric loss Q _o and resonance at a resonance frequency of about 7 GHz were measured for this sample. Frequency temperature coefficient τ _f (ppm /
Was measured by the postresonator method.

The relative permittivity Er, the dielectric loss Q, and the resonance frequency temperature coefficient τ _f (ppm / ° C.) of the ternary composition of the above general formula prepared by changing the values of x and y while keeping z constant. The changes in various dielectric properties due to changes in composition are shown in FIGS. From these figures, it will be apparent that the ternary dielectric ceramic composition according to the present invention has excellent dielectric properties as compared with compositions outside the scope of the present invention.

[0014]

As described above, according to the present invention, Ba (Z
n1 / 3 Ta2 / 3) O ₃ is partially substituted with BaZrO ₃ and BaSn.
A dielectric porcelain composition obtained by substituting O ₃ based material and having a Ba composition ratio in a state of being less than stoichiometric is set to an arbitrary value by well adjusting the resonance frequency temperature coefficient while maintaining a high Q value. It is very effective because it can be used well in the high frequency range.

[Brief description of drawings]

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

FIG. 2 is a graph showing changes in relative permittivity (Er) due to changes in the composition of the present invention.

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

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

Claims (1)

[Claims] 1. A general formula (1-x-y) Ba 1-z (Zn1 / 3 Ta2 / 3) O 3 + x
It is represented by Ba _1-z ZrO ₃ + yBa _1-z SnO ₃ , and 0.002 ≦ x ≦ 0.05, 0.002 ≦
A high frequency dielectric ceramic composition, wherein y ≦ 0.08 and 0.005 ≦ z ≦ 0.050.