JPS5829255B2 - Sankabutsuyudenzairiyo - Google Patents

Description

[Detailed description of the invention] The present invention provides Zn, Ca + Nb, or Zn, C
a, Nb.

It is composed of Ta and has a dielectric constant temperature coefficient of 0 to +140p.
It concerns oxide dielectric materials in the pm/'C range.

The purpose of the present invention is to reduce the dielectric loss (tan δ) in the range of dielectric constant (ε) ε≦20, and to reduce the dielectric constant temperature coefficient (εT).
The object of the present invention is to provide a composition suitable for capacitor materials and microwave dielectric materials in which the temperature (denoted as K) exhibits a positive temperature change.

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 quasi-millimeter wave and millimeter wave ranges, and along with the demand for microwave ICs, the technology has advanced, stabilizing oscillator frequencies, controlling delay times, and ICs for microwave circuits. The use of high-permittivity, low-loss dielectric materials for substrates and other materials is actively being considered for miniaturization.

As a conventional general dielectric material, 13aQ-T
The i02 series is known, but it shows a large value with a negative permittivity temperature coefficient, and a positive ρTK cannot be obtained9.
Alumina sintered body or MgT i 03 + CaT i
The 03 series etc. can obtain positive εTK, but have the drawback of low dielectric constant.

The present invention eliminates these drawbacks and newly uses Zn.
O, CaO, Nb2O5, or ZnO-Ca0-N
b In the dielectric composition composed of 205-Ta 205, 2(Ca1-XZnX)O-y(Nb2-zTa
It has been discovered that the composition of No. 2,05) can be synthesized into an excellent capacitor and microwave dielectric material.

Here, the present invention provides 2 (Ca 1-Xznx )”V(
In the composition coated with Nb2 'l'a 05), the value of X is O<X≦1.0. The value of y is 0.5≦y≦1
．． 6 + The value of Z is O≦Z<2. It is characterized by being within a composition range that satisfies O.

The sample is 2(Ca, -xZnX)O-y(Nb2-7.T
The composition of aZO5) is ZnO, CaCO3, Nb2O3,
The raw materials for Ta205 were weighed according to each composition, mixed in a ball mill, calcined at 1000°C for 3 hours, and compressed to 1150°C.
It was obtained by firing in air at 1450'C to 1450C for 5 hours.

After that, the dielectric constant was measured at room temperature at 9 GHz, and the temperature coefficient was determined as IMH.
Measured at z.

The following will be explained based on examples.

Example 1 2 (Ca 1 x Z n x ) Q y (
Table 1 shows each characteristic when the values of X1 and y are changed when 2=0 in the composition of N b 2 z T az 05).

Table 1 shows that <O<X≦1.0, 0.5≦y<1.
ε≦20 in the range of 6. Temperature coefficient of ε is 140 ppm/℃
An oxide dielectric material having the following properties can be obtained.

X=O has the disadvantage that εTK is large, and y<0.5
, Even in the range of y≦1.6, ρTK is thick and ta
There is a drawback that nδ is large.

Example 2 2 (Ca 1 x Z n x ) 0-y (N
b 2- z T az 05) with the composition of X, y, Z
Table 2 shows each characteristic when each value of is changed.

As is clear from Table 2, when Ta is substituted with NbG, εTK tends to decrease, and x=0.8. yl, 0
, a small value of ρTK-9.0 ppm/°C can be obtained at z=0.8.

When z = 2.0, ρTK and tanδ become too small to be practical, and the effective composition range of Z is O≦Z〈
2, in the range of O.

As described above, it can be seen that the composition of the present invention is an excellent material having a dielectric constant of 2.0 or more, a small dielectric loss, and a small temperature change in the dielectric constant.

It is clear that these materials are extremely useful as microwave dielectric materials having a large dielectric constant and a small temperature change in the dielectric constant in the microwave, quasi-millimeter wave, and millimeter wave regions.

It was also confirmed that this material has low dielectric loss even in the low frequency range, and small temperature changes in dielectric constant, making it an excellent material for use as a ceramic capacitor.

Claims (1)

[Claims] 12(Cax Zn)O-y(Nb2-T
In the composition prepared by a05), the value of X is O<
x≦1, o+y value is 0.5≦y<1.6, z value is 0≦2<2. An oxide dielectric material characterized by having a composition that satisfies the conditions of O.