JPS596002B2 - Sankabutsuyudenzairiyou - Google Patents

Description

Detailed Description of the Invention The present invention is composed of La, Ti, S, Zn, and Nb, and has a dielectric constant temperature coefficient of -700 to +700 pμm/
The present invention relates to an oxide dielectric material for temperature compensation in the range of C.

The purpose of the present invention is to provide a dielectric loss (ta) when the dielectric constant ε is 40 or more.
nδ) is small and the temperature coefficient of dielectric constant (εT) is small.

It is an object of the present invention to provide a composition suitable for a microwave dielectric material and a capacitor material, which can control the value of . In the microwave region, dielectric materials have been conventionally applied to impedance matching of microwave circuits, dielectric resonators, etc.

In particular, with the recent increase in communication networks, the frequency range used has expanded to the low range, sub-millimeter wave, and millimeter wave ranges, and with the demand for microwave ICs, the technology has advanced, stabilizing the oscillator frequency and controlling the delay time. Furthermore, studies are actively underway to miniaturize IC substrates for microwave circuits and the like by using dielectric materials with high dielectric constant and low loss. BaO-TiO2-based dielectric materials are known as conventional general dielectric materials, but they exhibit a large negative temperature coefficient of dielectric constant, and it has been difficult to control the dielectric constant to any positive or negative value.

Furthermore, alumina sintered bodies, MgTiO3, CaTi03, etc. can be used to obtain positive εT, but they have the drawbacks of low dielectric constant and large dielectric loss. The present invention eliminates these drawbacks and newly adds La, Ti, B, Nb, and Zn.
In an oxide dielectric composition composed of x(La2T
i207)y(Sr2Nb207)2(Zn2Nb20
7) An excellent microwave dielectric material can be obtained by synthesizing the composition of
It was discovered that it can be used as a material for capacitors.

Here, the present invention provides x(La2Ti207)y(Sr2N
b207) In the composition coated with Z (Zn2Nb207), the value of X is 0≦X<1.0 | the value of y is 0≦y≦
0.6, and the value of z is within a composition range satisfying 0<z≦0.3.

The sample is x(La2Ti207)y(Sr2Nb207)
With the composition of Z (Zn2Nb207), La203, TiO2
, SrC03, ZnO, and Nb2O5 according to each composition, and mixed in a ball mill at 1000°C for 4 hours.
After calcination and compression molding, the material was calcined at 1200 DEG C. to 1380 DEG C. for 2 hours in air or in an oxygen stream. Thereafter, the dielectric constant was measured at room temperature at 9GH2 and the temperature coefficient was measured at 1MH2. x(La2Ti207)y(5
2Nb207) Z (value of X in the composition of Zn2Nb2~,
Table 1 shows each characteristic when the value of y and the value of z are changed.

As shown in Table 1, La2Ti2O7/Sr2Nb2
When the composition ratio of O7/Zn2Nb2α◆ is changed, Sr2
Nb2Ol, that is, as the value of y increases, the temperature coefficient of dielectric constant decreases. Between the composition of y-0.125 and 0.15, it ranges from +45 ppm/C to -30 ppm/°C.
This shows a small value.

In particular, the composition of x=0.765, y00.135, and z=0.1 shows a small value of -2 to -4 ppm/°C.
Furthermore, as the value of y increases, T-K changes from positive to negative ε.
The indicated value shows a tendency to increase.

When y〈0.6, εT. V1 or Tan where K is negatively large
δ also becomes large, which is not practical. When Z>0.3, ε becomes 30 or less regardless of the composition of any combination of X and y, and is excluded from the present invention. As described above, by appropriately selecting the values of X, y, and z, positive or negative εT. It is possible to obtain the value of K.

On the other hand, the sintered body can be obtained at a relatively low firing temperature of 1220°C to 1380°C, which is economical. As described above, the composition of the present invention has a dielectric constant of 30 or more, low dielectric loss, and a small temperature coefficient of dielectric constant, and is an excellent material that can obtain any positive or negative value. Recognize.

Claims (1)

[Claims] 1 x(La_2Ti_2O_7)y(Sr_2Nb_
2O_7)z(Zn_2Nb_2O_7) (where x+y+z=1), the value of X is 0
≦x<1.0, y value is 0≦y≦0.6, z value is 0<
An oxide dielectric material characterized by having a composition that satisfies the condition of z≦0.3.