JPS6020852B2 - Porcelain dielectric material for temperature compensation - Google Patents

Description

[Detailed description of the invention] The present invention'Maagi i207・Ca2NQ.

7↓ Mg2xTi2-2x04 pine (but 0 mix x SI.0)
This relates to a ceramic dielectric material of the type represented by .

The present invention has a large dielectric constant, low yield loss, and the temperature coefficient of the dielectric constant can be freely changed over a wide range.
The present invention also provides a temperature-compensating ceramic dielectric material whose temperature coefficient does not change over a wide temperature range. Temperature-compensating porcelain capacitors are often used as circuit elements in communication equipment, color televisions, etc. In this case, it is always desirable to have a high dielectric constant and low dielectric loss, and the temperature coefficient can be set to any specified value. It is also desired to maintain a constant value with respect to temperature.

Until now, this type of material has been used as SrTi03, CaT
Compositions containing i03, MgTi03, CaZr03, etc. as main components have been used, but these materials have small dielectric constant values of 30 to 16 when the temperature coefficient of the yield rate is small, and furthermore, the temperature coefficient of the temperature coefficient is small. The dependence, that is, the change in the temperature coefficient with respect to temperature, was also large, as it was more than ±6 flies/°C.

Furthermore, materials with a large temperature coefficient of dielectric constant have the disadvantage that the temperature coefficient varies greatly with temperature. Therefore, as one of the materials to compensate for these drawbacks, 203-Tj
021 Mg○-based materials were developed (Hakama Kaisho 49-12
400). In this system, we have succeeded in reducing the temperature coefficient to almost zero, and the temperature dependence of the temperature coefficient has also been improved to some extent. However, it has been impossible to adjust the temperature coefficient depending on the purpose. The present invention improves these drawbacks. Salvation even skin 7・C is also an N product, Ryo OMg2. T
By synthesizing the ceramic dielectric material of the system shown by i2-2X○4-public (OSx Mi 1.0), it has a high dielectric constant and low dielectric loss, and the temperature coefficient of the dielectric constant can be freely changed over a wide range. The authors discovered that this material can be an excellent temperature-compensating porcelain dielectric material that has a constant temperature coefficient of permittivity over a wide temperature range.

Furthermore, the firing temperature was relatively low, and the composition was found to be easy to manufacture, so it was released. The effectiveness of the present invention will be explained below based on Examples.

NQ of Example 2Ti207・C.

7.Kyo Mg2XTi2X04 (.

For porcelain dielectric materials composed of < × Mi 1.0), L
Brush off the powders of Mo03, Ti02, CaC03, Nb2Q, and Mg0 and make 2 skins 7.Ca2NQ. 7・dig2XTi2-2
×.

Regarding the porcelain dielectric material composed of enemy (x = 0), France 2
03, Ti02, CaC03, and Nb2Q powders were weighed according to each composition, mixed in a ball mill, filtered,
The seeds were dried and incubated for 2 hours from 100 p.m. to 1200 p.m. After that, it is pressure-formed into a disc on the diameter 16 side, and
Firing was carried out under conditions of 00 to 145 pi and for 1 to 2 hours. After baking silver electrodes on both sides of the obtained porcelain at 600°C, dielectric properties were measured under the following conditions. The dielectric constant and dielectric loss were measured using a capacitance bridge at a frequency of IKHz. The temperature coefficient is the dielectric constant value -30℃, 000, 2
The dielectric constant was measured at temperatures of 55° C., 85° C., and the dielectric constant value at 20:00 was used as a reference. Here, the temperature coefficient was calculated according to the following formula.

Above J1 Gohan TK = Go 2 lights - 2 However, TKs: Temperature coefficient (chest/°C) ^: Value of yield rate at T°C: Value of permittivity at 20q0 T: Measured temperature obtained Representative examples of the results are listed in Table 1.

In addition, soil is indicated in the temperature coefficient column of Table 1 because the temperature coefficient at each degree from -3pi○ to 85q0 is ±
It is shown that it is within the range of

Table 1 Table 1 No. 15-1~NO. The composition of No. 15-3 is outside the scope of the claims of the present invention.

As is clear from Table 1, Ni2Ti207, Ca2NQ
.

7 “or&Ti2-2×.

Porcelain materials composed of 100% (omix x q.0) exhibit excellent properties such as high dielectric constant and low dielectric loss.Furthermore, by adjusting the composition ratio, the value of the temperature coefficient can be reduced to approximately 100%. It is clear that the temperature can be adjusted over a very wide range from 12°C to -47 blood/°C.Moreover, the change in temperature coefficient with respect to temperature is within ±30°C or within ±10% of the temperature coefficient. On the other hand, there is 2Ti2.
Composition range where 07 is less than 5 mol% and C is also NQ07
is 95 mol% or more and g2XTi2-2
×. In the composition range of 4 pine trees (O3Xq・Oshu 8%), the change in temperature coefficient with respect to temperature is within ±3°C,
Alternatively, the condition that the temperature coefficient be within ±10% and the condition that the dielectric constant value be 30 or more are not satisfied at the same time.

Based on the above, the composition range of the present invention is limited to the following composition range.

France 2Ti207・Ca2NQ.

7, Sag2XTi2-2×.

In the three-component system of enemy (.mix xSI.0), Q[i2Ti
207]. 8 [Ca2NQ.

7]. y [ヂ&Ti2-2×04-2X] (However, Q+
80y=1), the values of Q, 8, and y are each 0.053Q<1.0 0<Pku0.9u 0<yku0
．． A porcelain dielectric material for temperature compensation, characterized in that it has a composition made within a range satisfying 8.

Claims (1)

[Claims] 1 La_2Ti_2O_7, Ca_2Nb_2O_7
, 1/2Mg_2_xTi_2_-_2_xO_4_-
In the three-component system of _2_x (0≦x≦1.0) α[L
a_2Ti_2O_7]・β[Ca_2Nb_2O_7
]・[1/2Mg_2_xTi_2_-_2_xO_4
____2_x] (however, α+β+γ=1.0), the values of α, β, and γ are each 0.05≦α<1.0
, 0<β<0.95, and 0<γ≦0.8.