JP3101965B2 - Dielectric porcelain composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric ceramic composition having a high Q value in a high frequency range such as a microwave and a millimeter wave, and is used in a frequency range such as a microwave and a millimeter wave. The present invention relates to a dielectric ceramic composition that can be used for various resonator materials, MIC dielectric substrate materials, dielectric waveguide materials, and multilayer ceramic capacitors.

[0002]

2. Description of the Related Art Hitherto, dielectric ceramics have been widely used in dielectric resonators, MIC dielectric substrates, waveguides, and the like in high-frequency regions such as microwaves and millimeter waves.

[0003] Conventionally, as this kind of dielectric porcelain,
For example BaO-TiO ₂ material, ZrO-SnO ₂ -Ti
An O ₂ material or the like is known, and has characteristics of a dielectric constant of 35 to 40, a Q value of about several thousand to 10,000 at 10 GHz, and a temperature coefficient τf of a resonance frequency of ± 10 ppm / ° C. or less.

[0004]

Recently, attempts have been made to use higher frequency bands in the communication field and the like, and higher Q values are required for dielectric materials. As the dimensions of resonators, substrates, and the like become smaller as the number of applications increases, an appropriate dielectric constant that is easy to handle in applications is required.

However, in the above-mentioned conventional materials,
Since the Q value is low and the dielectric constant is too high, it is currently not at a practical level when used in a high frequency band of 10 GHz or more.

Further, the conventional dielectric porcelain composition must be fired at a high temperature in order to improve the porcelain density, and it is difficult to obtain a sufficient porcelain density even at a high temperature. There was a problem that the strength was weak and it was difficult to obtain a high Q value.

The present inventors have studied materials capable of meeting such a demand, and found that a dielectric ceramic composition comprising BaO, MgO, WO ₃ and TaO _5/2 having a low dielectric constant and a high Q value. And applied for a patent in Japanese Patent Application No. 4-284322.

However, in recent years, a higher dielectric constant and a higher Q value have been required, and a higher strength has been required.

[0009]

[Means for Solving the Problems] The present inventors have studied materials capable of meeting such a demand and found that B
A composition comprising aO, MgO, WO ₃ and TaO _5/2 contains at least one of B, P, Si and an alkali metal element.
BaO, MgO, WO by containing more than
_3. It has been found that the ceramic density (bulk specific gravity) and the Q value can be improved as compared with the dielectric ceramic composition composed of TaO _5/2 , and the present invention has been achieved.

That is, the dielectric ceramic composition of the present invention contains at least Ba, Mg, W, and Ta as metal elements,
The composition formula based on the molar ratio of these components is xBaO.yMg
When expressed as O · zWO ₃ · wTaO _5/2, the x,
y, z, w are 0.40 ≦ x ≦ 0.55, 0.10 ≦ y
≦ 0.40, 0 <z ≦ 0.30, 0 <w ≦ 0.40,
0.20 ≦ z + w ≦ 0.40, x + y + z + w = 1.0
With respect to 100 parts by weight of the main component satisfying 0, the boric acid compound is 0.01 to 0.20 parts by weight in terms of B ₂ O ₃ , and the phosphorus compound is 0.005 to 1 part by weight of the P content.
Parts by weight, SiO _{2 in an amount} of 0.01 to 1 part by weight, and an alkali metal-containing compound in an amount of 0.02 in terms of carbonate.
1 part by weight or more and less than 1 part by weight, and at least one selected from the above.

Further, at least Ba, M
g, W, when containing Ta, representing a composition formula by molar ratio of these components with _{xBaO · yMgO · zWO 3 · wTaO} 5/2, the x, y, z, w is, 0.40 ≦ x ≤
0.55, 0.10 ≦ y ≦ 0.40, 0 <z ≦ 0.3
0, 0 <w ≦ 0.40, 0.20 ≦ z + w ≦ 0.40,
With respect to 1 mol part of the composition satisfying x + y + z + w = 1.00, Sn, Mn, Ca and Group 3a of the periodic table, 4
With respect to 100 parts by weight of a main component containing at least one element selected from Group a elements at a ratio of 0.2 mol part or less, a boric acid compound is used in an amount of 0.01 to 0.2 parts by weight in terms of B ₂ O _3.
0 parts by weight or less, phosphorus compound in a P content of 0.005 parts by weight or more and 1 part by weight or less, and SiO _{2 in an amount} of 0.01 parts by weight or more and 1 part by weight.
Not more than 0.01 parts by weight, less than 1 part by weight of an alkali metal-containing compound in terms of carbonate, and at least one selected from the above.

In the present invention, at least B
a, Mg, W, containing _{Ta, xBaO · yMgO · zWO 3} · wTaO the formula by molar ratio of the components
_When expressed as _5/2 , the x, y, z, w are 0.40 ≦
x ≦ 0.55, 0.10 ≦ y ≦ 0.40, 0 <z ≦ 0.
30, 0 <w ≦ 0.40, 0.20 ≦ z + w ≦ 0.4
0, x + y + z + w = 1.00 as the main component, but the molar ratio x of BaO is 0.40 ≦ x ≦ 0.
The reason for setting the value to 55 is that when x is less than 0.40, the Q value decreases and sintering becomes difficult, and when x exceeds 0.55, the Q value decreases. x is particularly preferably 0.45 ≦ x ≦ 0.55.

Further, the molar ratio y of MgO is 0.10 ≦ y ≦
The reason for setting the value to 0.40 is that if y is less than 0.10, sintering becomes difficult or the Q value is reduced, and if y exceeds 0.40, the Q value is reduced. y is 0.1
0 ≦ y ≦ 0.30 is particularly desirable. Furthermore, the reason why the molar ratio z of WO ₃ is 0 <z ≦ 0.30 is that when z exceeds 0.30, the Q value decreases. z is 0.0
It is particularly desirable that 1 ≦ z ≦ 0.26. The reason _why the molar ratio w of TaO _5/2 was 0 <w ≦ 0.40 was that w was 0.40
This is because the Q value decreases in the above case. w is 0 <w
It is desirable that ≦ 0.33.

Further, the reason for setting 0.20 ≦ z + w ≦ 0.40 is that if z + w is less than 0.2 or exceeds 0.4, the Q value is reduced or sintering is poor. .

Also, in the present invention, 0.17 ≦ 5 |
It is desirable to satisfy x−0.5 | + y + 0.2z <0.94. If the value is less than 0.17 or 0.94 or more, the Q value tends to decrease or sintering tends to be poor.

Further, in the dielectric porcelain composition of the present invention,
The composition contains, as a main component, one containing at least one element selected from Sn, Mn, Ca and Group 3a and 4a elements of the periodic table in an amount of 0.2 mol part or less with respect to 1 mol part. Is also good. By containing at least one element selected from the group consisting of Sn, Mn, Ca and Group 3a and 4a elements of the periodic table in a proportion of 0.2 mol part or less, the sinterability is improved and the dielectric properties are improved. , In particular, the temperature coefficient τf of the resonance frequency can be shifted to the plus side. On the other hand, Sn, Mn, Ca and Group 3a of the periodic table,
This is because when at least one element selected from the group 4a elements is contained in an amount of more than 0.2 mol part, the Q value decreases.

And, in the dielectric ceramic composition of the present invention,
The boric acid compound is added to B based on 100 parts by weight of the main component.
0.01 to 0.20 parts by weight in terms of ₂ O ₃ ,
A phosphorus compound in a P content of 0.005 to 1 part by weight, SiO ₂ in a content of 0.01 to 1 part by weight,
It contains an alkali metal-containing compound in an amount of 0.01 to less than 1 part by weight in terms of carbonate, and at least one selected from the above.

Based on 100 parts by weight of the main component, the content of the boric acid compound is 0.01 to 0.2 parts by weight in terms of B ₂ O _3.
0 parts by weight or less means that if it is less than 0.01 parts by weight, there is no effect on lowering the firing temperature or increase the porcelain density (bulk specific gravity) and Q value, and if it exceeds 0.20 parts by weight, the Q value Is lower than 400. The content of the boric acid compound is desirably 0.025 to 0.2 parts by weight in terms of B ₂ O ₃ .

Further, the content of the phosphorus compound is 0.005 parts by weight or more and 1.00% by weight based on 100 parts by weight of the main component.
The reason why the content is set to 0 parts by weight or less is that if it is less than 0.005 parts by weight, there is no effect on lowering the sintering temperature and improve the porcelain density (bulk specific gravity) and Q value.
This is because the value is lower than 4000. The content of the phosphorus compound is desirably 0.025 to 0.05 parts by weight in terms of P.

Further, S was added to 100 parts by weight of the main component.
The reason that the content of iO _{2 is set} to 0.01 part by weight or more and 1.00 part by weight or less is that if it is less than 0.01 part by weight, there is no effect on lowering the firing temperature and improving the porcelain density (bulk specific gravity) and Q value.
If the amount exceeds 1.00 parts by weight, the Q value will be lower than 4000. SiO ₂ is at least 0.01 parts by weight and 0.1
It is desirable that the amount be not more than part by weight.

The reason why the content of the alkali metal-containing compound is set to 0.01 part by weight or more and less than 1 part by weight, based on 100 parts by weight of the main component, is that when the amount is less than 0.01 part by weight, the calcination temperature is lowered. There is no effect on the reduction or improvement of the porcelain density (bulk specific gravity) and the Q value.
This is because it is lower. The content of the alkali metal-containing compound is desirably 0.01 to 0.9 parts by weight in terms of carbonate.

Here, boric acid compounds include B ₂ O ₃ , colemanite, CaB ₂ O ₄ , ZnB ₂ O _{4 and the} like. Further, examples of the phosphorus compound include H ₃ PO ₄ and P ₂ O ₅ . As the alkali metal, Li, Na, K, Rb,
There is Cs.

As a method for producing a porcelain based on the present invention, for example, an oxide of Ba, Mg, W or Ta or a metal salt such as a hydroxide, a carbonate or a nitrate which forms an oxide upon firing is used as a raw material. These are weighed so as to fall within the above-mentioned range of the main components, and then sufficiently mixed. Thereafter, the mixture is calcined at 900 to 1300 ° C. For example, a boric acid compound such as B ₂ O ₃ , a phosphorus compound such as P ₂ O ₅ , SiO ₂ , Li ₂ C
At least one of alkali metal-containing compounds such as O ₃ is weighed and added to a predetermined amount, mixed and pulverized. Then, it is formed into a predetermined shape by a forming method such as press forming or doctor blade method. Next, the molded body is fired at 1300 to 1600 ° C. in an oxidizing atmosphere such as the air to obtain a dielectric ceramic.

[0024]

According to the dielectric ceramic composition of the present invention, Ba, Mg,
For the main component containing W, Ta or S
With respect to a main component containing at least one selected from n, Mn, Ca, and elements of Groups 3a and 4a of the periodic table,
By containing boric acid compounds, phosphorus compounds, SiO ₂ and alkali metal-containing compounds in predetermined amounts, BaO, Mg
It has a higher porcelain strength and Q value than the composition consisting of O, WO ₃ and TaO _5/2 , has a Q value of 4000 or more, and freely controls the temperature coefficient τf of the resonance frequency in a certain region. And high strength can be realized by high porcelain density (bulk specific gravity).

[0025]

【Example】

Example 1 As raw materials, BaCO ₃ and MgCO _{3 having} a purity of 99% or more,
Using WO ₃ and Ta ₂ O ₅ powders, the compositions were weighed so as to have the composition shown in Table 1, and wet-mixed in a ball mill for 20 hours using pure water as a medium. Next, the mixture was dried (dehydrated) and calcined at 1200 ° C. for 2 hours. The calcined product is pulverized, formed into a predetermined shape, and baked at 1400 to 1550 ° C. for 6 hours.
The value and the temperature coefficient τf of the resonance frequency were determined. Table 2 shows the results. Further, B ₂ O ₃ , H ₃ PO
₄ , SiO ₂ and alkali metal-containing compounds are shown in Table 3 respectively.
After weighing so as to have the ratios shown in Table 6, using isopropyl alcohol as a medium and wet-mixing with a ball mill for 20 hours, paraffin wax as a binder is added in an amount of 1 to 1.
After adding 10% by weight, the mixture was dried and sized through a mesh.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

[Table 4]

[0030]

[Table 5]

[0031]

[Table 6]

Next, the sized product was formed into a column having a diameter of 10 mm and a height of 5 mm at a pressure of about 1 ton / cm ² . Further, this molded body was fired in the atmosphere at 1400 to 1550 ° C. for 2 hours to obtain a dielectric ceramic. The porcelain thus obtained is JIS
The bulk specific gravity was determined based on the standard C2141-1978 (test method for ceramic materials for electrical insulation). In addition, both surfaces of the porcelain were polished flat, and a sample for evaluating dielectric properties (diameter: 8 m)
m, a columnar shape with a height of 6 mm). For the evaluation of the dielectric properties, the relative permittivity and the Q value at a frequency of about 10 GHz were measured using the sample by the dielectric cylinder resonator method. Also,
The resonance frequency in a temperature range of −40 to 85 ° C. was measured, and the temperature coefficient τf of the resonance frequency was calculated based on the resonance frequency at 25 ° C.

Table 1 shows the composition of the main component, and Table 2 shows the bulk specific gravity, relative dielectric constant, Q value and temperature coefficient τf of the resonance frequency of the main component.
And Tables 3 to 6 show the contents of B, P, Si, and alkali metal, each converted into a predetermined compound, and the results of bulk specific gravity, relative dielectric constant, Q value, and temperature coefficient τf of resonance frequency.

According to Tables 1 to 6, the dielectric porcelain composition of the present invention contains B, P, Si, and an alkali metal to form BaO, MgO, WO ₃ , and TaO _5/2.
It can be seen that the bulk specific gravity and the Q value are improved as compared with the composition consisting of, and that the relative dielectric constant is 15 or more, the Q value is 4000 or more, and the temperature coefficient τf of the resonance frequency is within ± 30 ppm / ° C.

Example 2 BaCO ₃ , MgCO _{3 having} a purity of 99% or more as raw materials
WO ₃ , Ta ₂ O ₅ and Y ₂ O ₃ , La ₂ O ₃ , Ce
O ₂ , Nd ₂ O ₃ , Pr ₆ O ₁₁ , Sm ₂ O ₃ , Hf
O ₂ , ZrO ₂ , MnCO ₃ , SnO ₂ , TiO ₂ , C
Using aCO ₃ , the powder was weighed in the proportions shown in Table 7, and a porcelain was prepared in the same manner as in Example 1 and the same measurement was performed. Table 7 shows the composition, and Table 8 shows the bulk specific gravity, relative permittivity, Q value,
The measurement results of the temperature coefficient τf of the resonance frequency are shown.

[0036]

[Table 7]

[0037]

[Table 8]

According to Tables 7 and 8, the main component is S
Even when a predetermined amount of at least one element selected from n, Mn, Ca and elements of Groups 3a and 4a of the periodic table is contained, B,
By containing P, Si and an alkali metal, Ba
_{O, MgO, WO 3, TaO} 5 / mocha of specific gravity and a Q value than the _second composition consisting of is improved, relative dielectric constant of 15 or more, Q
Value is 4000 or more, temperature coefficient τf of resonance frequency is ± 30
It can be seen that it has excellent characteristics within ppm / ° C. The main components are Sn, Mn, Ca and Periodic Table No. 3a.
Group 4a element, the temperature coefficient τ of the resonance frequency
f shifts to the plus side, indicating that the dielectric properties can be controlled.

[0039]

As described in detail above, according to the present invention, B
_{aO, MgO, WO3, Ta 2} O consists of ₅ principal components Sn or thereto,, Mn, Ca and periodic table 3a
B, P, S with respect to the main component containing Group 4a element
i, by containing a predetermined amount of an alkali metal element,
The bulk specific gravity is improved and the strength can be increased as compared with the composition comprising aO, MgO, WO ₃ , and TaO _5/2 , and the Q value at 10 GHz is high, and the Q value at 10 GHz is high.
It has high characteristics of at least 4000 or more, and can control the temperature coefficient τf of the resonance frequency within ± 30 ppm / ° C. Further, by containing Sn, Mn, Ca and elements of Groups 3a and 4a of the periodic table as main components, sinterability is improved, and the temperature coefficient τf of the resonance frequency shifts to the plus side, and the dielectric constant increases. Can control characteristics.

Accordingly, various resonator materials and MICs used in a frequency range such as microwaves and millimeter waves can be used.
It can be optimized for a dielectric substrate material for use, a material for a dielectric waveguide, and the like.

Claims (8)

(57) [Claims] (1) at least Ba, Mg,
W, when containing Ta, representing a composition formula by molar ratio of these components with _{xBaO · yMgO · zWO 3 · wTaO} 5/2, the x, y, z, w is, 0.40 ≦ x ≦ 0 .55 0.10 ≦ y ≦ 0.40 0 <z ≦ 0.30 0 <w ≦ 0.40 0.20 ≦ z + w ≦ 0.40 x + y + z + w = 1.00 Based on 100 parts by weight of the main component And a boric acid compound in an amount of 0.01 to 0.20 parts by weight in terms of B ₂ O ₃ . 2. At least Ba, Mg,
W, when containing Ta, representing a composition formula by molar ratio of these components with _{xBaO · yMgO · zWO 3 · wTaO} 5/2, the x, y, z, w is, 0.40 ≦ x ≦ 0 .55 0.10 ≦ y ≦ 0.40 0 <z ≦ 0.30 0 <w ≦ 0.40 0.20 ≦ z + w ≦ 0.40 x + y + z + w = 1.00 Based on 100 parts by weight of the main component 1. A dielectric porcelain composition comprising a phosphorus compound in an amount of 0.005 to 1 part by weight in terms of P. 3. The method according to claim 1, wherein at least Ba, Mg,
W, when containing Ta, representing a composition formula by molar ratio of these components with _{xBaO · yMgO · zWO 3 · wTaO} 5/2, the x, y, z, w is, 0.40 ≦ x ≦ 0 .55 0.10 ≦ y ≦ 0.40 0 <z ≦ 0.30 0 <w ≦ 0.40 0.20 ≦ z + w ≦ 0.40 x + y + z + w = 1.00 Based on 100 parts by weight of the main component , dielectric ceramic composition is characterized by adding containing SiO ₂ less than 1 part by weight 0.01 part by weight. 4. At least Ba, Mg,
W, when containing Ta, representing a composition formula by molar ratio of these components with _{xBaO · yMgO · zWO 3 · wTaO} 5/2, the x, y, z, w is, 0.40 ≦ x ≦ 0 .55 0.10 ≦ y ≦ 0.40 0 <z ≦ 0.30 0 <w ≦ 0.40 0.20 ≦ z + w ≦ 0.40 x + y + z + w = 1.00 Based on 100 parts by weight of the main component A dielectric porcelain composition characterized by containing an alkali metal-containing compound in an amount of 0.01 to less than 1 part by weight in terms of carbonate. 5. At least Ba, Mg,
W, when containing Ta, representing a composition formula by molar ratio of these components with _{xBaO · yMgO · zWO 3 · wTaO} 5/2, the x, y, z, w is, 0.40 ≦ x ≦ 0 .55 0.10 ≦ y ≦ 0.40 0 <z ≦ 0.30 0 <w ≦ 0.40 0.20 ≦ z + w ≦ 0.40 x + y + z + w = 1.00 With respect to 1 mol part of the composition , Sn, Mn, Ca
And a borate compound of B ₂ O with respect to 100 parts by weight of a main component containing 0.2 mol part or less (not including 0) of at least one element selected from Group 3a and 4a elements of the periodic table. A dielectric porcelain composition characterized by being added in an amount of from 0.01 part by weight to 0.20 part by weight in terms of ₃ . 6. At least Ba, Mg,
W, when containing Ta, representing a composition formula by molar ratio of these components with _{xBaO · yMgO · zWO 3 · wTaO} 5/2, the x, y, z, w is, 0.40 ≦ x ≦ 0 .55 0.10 ≦ y ≦ 0.40 0 <z ≦ 0.30 0 <w ≦ 0.40 0.20 ≦ z + w ≦ 0.40 x + y + z + w = 1.00 With respect to 1 mol part of the composition , Sn, Mn, Ca
The phosphorus compound is added to P based on 100 parts by weight of a main component containing at least one element selected from Group 3a and 4a elements of the periodic table in a proportion of 0.2 mol part or less (not including 0).
A dielectric porcelain composition characterized by being added in an amount of 0.005 to 1 part by weight. 7. At least Ba, Mg,
W, when containing Ta, representing a composition formula by molar ratio of these components with _{xBaO · yMgO · zWO 3 · wTaO} 5/2, the x, y, z, w is, 0.40 ≦ x ≦ 0 .55 0.10 ≦ y ≦ 0.40 0 <z ≦ 0.30 0 <w ≦ 0.40 0.20 ≦ z + w ≦ 0.40 x + y + z + w = 1.00 With respect to 1 mol part of the composition , Sn, Mn, Ca
And Periodic Table Group 3a, relative to 100 parts by weight of the main component containing a proportion of at least one kind of 0.2 molar parts or less selected from the group 4a elements (not including 0), the SiO ₂ 0.
A dielectric porcelain composition characterized by being added in an amount of from 01 parts by weight to 1 part by weight. 8. At least Ba, Mg,
W, when containing Ta, representing a composition formula by molar ratio of these components with _{xBaO · yMgO · zWO 3 · wTaO} 5/2, the x, y, z, w is, 0.40 ≦ x ≦ 0 .55 0.10 ≦ y ≦ 0.40 0 <z ≦ 0.30 0 <w ≦ 0.40 0.20 ≦ z + w ≦ 0.40 x + y + z + w = 1.00 With respect to 1 mol part of the composition , Sn, Mn, Ca
And an alkali metal-containing compound is carbonated with respect to 100 parts by weight of a main component containing at least one element selected from Group 3a and 4a elements of the periodic table in a proportion of 0.2 mol part or less (not including 0). A dielectric porcelain composition characterized by being added in an amount of 0.01 to less than 1 part by weight in terms of salt.