JPS5848965B2 - Porcelain dielectric composition for temperature compensation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature-compensated porcelain dielectric assembly having a low temperature coefficient, a high dielectric constant, and a small loss angle at high frequencies.

Conventionally, as a temperature compensating porcelain dielectric composition, MgTi0
3. CaTi03, SrTi03, Ti02, etc. have been used, but these have the disadvantage that when the temperature coefficient becomes small, a high dielectric constant cannot be obtained and the loss angle also deteriorates.

Note that CaTiO3 has a dielectric constant of 160 and a temperature coefficient of -1600.
p-, and S r TiO s has the characteristics of dielectric constant 360 and temperature coefficient -4500 PI)Ill, and as an improvement of these, Bi203 or B t 2 0 3 and T
Although there are methods to reduce the temperature coefficient by adding iO2 at the same time, these methods have a large loss angle at high frequencies and are unstable in terms of characteristics.

The present invention eliminates such drawbacks, and the SrTiO3
CaT
Add O to 10 parts by weight of iSi05 (however, excluding O), and further add Bi203, Fe203, Mn02, Ca
By combining two or more auxiliary oxides of O and V205, O
This relates to a temperature compensating porcelain dielectric composition to which ~5 parts by weight (excluding O) is added.

Hereinafter, the invention will be specifically explained in detail by giving examples.

Example Commercially available SrCO3, CaCO3 and TiO2 were mixed in equal moles, pre-calcined at 1100-1200°C for 2H, and finely pulverized to create SrTt03, CaTtO3, and in the same way CaCO3 and S I02 Tt02 were mixed in equal moles. and calcined at 1100 to 1300°C for 2 hours and pulverized to produce CaTiSiO5.

Next, these raw materials were mixed to have the component ratios shown in Table 1, wet-mixed using a urethane-lined pot mill to evaporate water, and then an aqueous PVA (polyvinyl alcohol) solution was added as a binder, and after drying. , diameter 10mm
A disk with a thickness of 2 times was press-molded at a pressure of 0.5 to 2 t/crA, and main firing was performed at 1200 to 1400° C. for 3 hours.

Ag--Pd electrodes were baked onto the obtained porcelain body to obtain a completed body, and the electrical properties were measured, and the results shown in Table 2 were obtained.

In the table, from the results of A3 to A7, the basic components S r T t
When O3 exceeds 90% by weight, the temperature coefficient is -3000
ppm/'C, and from the results of samples A95 to 99, when CaTiO3 exceeds 90% by weight, the dielectric constant becomes 180.
SrTiO3 is 10 to 90% by weight, CaTiO3 is 9% by weight, and the desired high dielectric constant cannot be obtained.
The ingredients were limited to 0 to 10% by weight, and sample Arashi 11,2
4, 32, 41, 64, 79, and 94, when the amount of rare earth oxide exceeds 15 parts by weight based on the basic composition, the dielectric constant decreases, the dielectric loss increases significantly, and the capacitance decreases over time. Since the amount of change increases, the amount added is limited to O to 15 parts by weight (however, O is not included).

In addition, in addition to the rare earth oxides shown in the table, Gd203, Y
b203, Pr6011, Eu203, Dy203
, Er203, Tm203, Lu203, etc., and similar results were obtained.

Furthermore, from the results of samples A17, 34, 63, 68, and 82, when the auxiliary oxide exceeds 5 parts by weight based on the basic composition, the dielectric constant decreases significantly, the dielectric loss increases, and the sinterability decreases. The amount of addition is limited to 0 to 5 parts by weight (however, excluding O) because the strength is lowered.

Note that the results for samples A16, 43, and 72 show that the addition of the auxiliary oxide alone does not sufficiently improve the properties.
Since they have drawbacks such as low dielectric constant and large dielectric loss, they are added in combination of two or more types.

Furthermore, from the results of samples A28, 39, 42, 59, and 89, if CaTiSiO exceeds 10 parts by weight based on the basic composition, the dielectric constant decreases and dielectric loss increases.
Limited to parts by weight (excluding 0).

In addition, by adding CaTiSi05 in the form of a composite oxide, the sinterability is improved compared to the case of adding simple oxides such as TiO2, SiO2, etc., resulting in a high dielectric constant, low temperature coefficient, and a high strength. Due to this significant improvement, it has become easier to manufacture thinner porcelain.

That is, in the present invention, rare earth oxide and CaTiSi
By adding O and auxiliary oxide in combination, it has a high dielectric constant, low temperature coefficient, low dielectric loss at high frequencies, and high strength, making it possible to maintain the substrate even when manufacturing thin porcelain. The object of the present invention is to provide a ceramic dielectric composition for temperature compensation/compensation that has extremely small warpage and good workability.

Claims (1)

[Claims] 1 SrTiO3 10-90% by weight, CaTi0390
~． For 100 parts by weight of the basic composition of 10% by weight, O to 15 parts by weight of rare earth element oxides with atomic numbers 57 to 71 (excluding O), O to 10 parts by weight of CaTiSio5 (
However, O is not included), and in addition, B103, Al203
, Fe203, Mn02, CoO, v205. A ceramic dielectric composition for temperature compensation comprising a composite of two or more auxiliary oxides such as 0 to 5 parts by weight (excluding O).