JP3101968B2 - 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 microwaves and millimeter waves, and is used in a frequency range such as microwaves and millimeter waves. 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
O ₂ materials and the like are known, and have characteristics of a dielectric constant of 35 to 40, a Q value of about 1,000 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. Further, as the operating frequency increases, the dimensions of the resonator, the substrate, and the like become smaller, so that a 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, it is necessary to fire at a high temperature in order to improve the density of the porcelain, and it is difficult to obtain a sufficient porcelain density even if firing at a high temperature. There was a problem.

The present inventors have studied materials capable of meeting such a requirement, and have developed a dielectric ceramic composition comprising Ba, Mg, and WO ₃ having a low dielectric constant and a high Q value. A patent application was filed in Japanese Patent Application No. 4-293165.

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
For a composition comprising aO, MgO, and WO ₃ , B,
By including at least one of P, Si and an alkali metal element in a predetermined amount, it is possible to improve the porcelain density (bulk specific gravity) and the Q value as compared with the dielectric porcelain composition comprising BaO, MgO and WO _3. And found the present invention.

[0010] That is, the dielectric ceramic composition of the present invention, when containing at least Ba, Mg, W as the metal element, representing a composition formula by molar ratio of these components with xBaO · yMgO · zWO _3, wherein x, y, z are 0.40 ≦ x ≦ 0.
60, 0.13 ≦ y ≦ 0.40, 0.20 ≦ z ≦ 0.3
0, x + y + z = 1, or at least one element selected from Group 3a elements of the periodic table in an amount of 0.1 to 30 mol parts per 100 mol parts of the composition. At least one selected from Sn, Mn, Ca and Group 4a element of the periodic table in an amount of 0.1 to 20 parts by mole based on 100 parts by mole of the main component or the composition. For 100 parts by weight of the main component,
The boric acid compound is used in an amount of 0.01 part by weight or more in terms of B ₂ O ₃ .
20 parts by weight or less, phosphorus compound in an amount of 0.005 to 1 part by weight in terms of P, 0.01 to 1 part by weight in terms of SiO ₂ , and 0.01% in weight of an alkali metal-containing compound in terms of carbonate. To less than 1 part by weight, and at least one selected from the above.

[0011] The dielectric ceramic composition of the present invention, when representing a composition formula by molar ratio xBaO · yMgO · zWO _3, wherein x, y, z is, 0.40 ≦ x ≦ 0.60,0.
13 ≦ y ≦ 0.40, 0.20 ≦ z ≦ 0.30, x + y
The main component is that satisfying + z = 1.
The reason why the molar ratio x of BaO is set to 0.40 ≦ x ≦ 0.60 is that if x is out of this range, the Q value decreases. Further, the molar ratio y of MgO is set to 0.13 ≦ y ≦ 0.40
The reason is that if y deviates from this range, the Q value decreases. Further, the molar ratio z of WO ₃ is set to 0.20 ≦ z
≦ 0.30 because the Q value decreases when z is out of this range.

Further, in the dielectric porcelain composition of the present invention,
0.1 to 30 parts by mole of at least one element of Group 3a of the Periodic Table or at least one of Sn, Mn, Ca and Group 4a of the Periodic Table with respect to 100 parts by mole of the composition. The main component may contain 0.1 to 20 mol parts of one kind. By including at least one of Sn, Mn, Ca and a group 3a, 4a element of the periodic table in the main component in a predetermined amount, the temperature coefficient τf of the resonance frequency can be shifted to the plus side. The reason why the amount of these additives is limited to the above range is that at least one element of Group 3a elements of the periodic table is more than 30 mol parts, or that Sn, Mn, Ca and 4a of the periodic table are included. If the amount of at least one of the group III elements is more than 20 mole parts, the Q value will decrease significantly, and the group 3a element of the periodic table and S
When n, Mn, Ca and the Group 4a element of the periodic table are less than 0.1 mol part, the effect of adding these elements is hardly obtained.

In the dielectric ceramic composition of the present invention, the boric acid compound is contained in an amount of 0.01 to 0.20 parts by weight in terms of B ₂ O ₃ , and the phosphorus compound is added in an amount of P based on 100 parts by weight of the main component. Not less than 0.005 parts by weight and not more than 1 part by weight, Si
0.01 to 1 part by weight in terms of O ₂ , and 0.01 to 1 part by weight of an alkali metal-containing compound in terms of carbonate.
Less than parts by weight, containing at least one selected from the above.

The content of the boric acid compound is 0.01 to 0.20 parts by weight in terms of B ₂ O _{3 based on} 100 parts by weight of the main component.
If the amount is less than 0.01 part by weight, there is no effect on lowering the firing temperature or improving the porcelain density (bulk specific gravity) and the Q value when the amount is less than 0.01 part by weight. It is because it falls. The content of the boric acid compound is desirably 0.025 parts by weight or more and 0.2 parts by weight or less in terms of B ₂ O ₃ from the viewpoint that a higher porcelain density and a higher Q value are obtained.

The reason why the content of the phosphorus compound is set in the range of 0.005 to 1 part by weight of P based on 100 parts by weight of the main component is that if the amount is less than 0.005 part by weight, the firing temperature is lowered. This is because there is no effect on the improvement of the porcelain density (bulk specific gravity) and the Q value, and when the content exceeds 1 part by weight, the Q value decreases. From the viewpoint of obtaining a higher porcelain density and a higher Q value, the phosphorus compound content is 0.025 parts by weight or more in terms of P amount.
It is desirable that the amount be not more than part by weight.

Further, Si is added to 100 parts by weight of the main component.
The reason that O _{2 is set} to 0.01 to 1 part by weight is as follows.
If the amount is less than 0.01 part by weight, there is no effect on lowering the firing temperature or the porcelain density (bulk specific gravity) and the Q value. If the amount exceeds 1 part by weight, the Q value decreases. SiO ₂ is desirably at least 0.1 part by weight and at most 1 part by weight from the viewpoint of obtaining a higher porcelain density and a higher Q value.

Further, an alkali metal-containing compound is used in an amount of 0.01 to 1 part by weight in terms of carbonate based on 100 parts by weight of the main component.
The reason why the amount is less than 1 part by weight is that if the amount is less than 1 part by weight, there is no effect on lowering the sintering temperature or the porcelain density (bulk specific gravity) and the Q value. is there.
The amount of the alkali metal-containing compound is desirably not less than 0.1 part by weight and less than 0.9 part by weight in terms of carbonate, from the viewpoint of obtaining a higher porcelain density and a higher Q value.

Here, B ₂ O ₃ ,
Colemanite, there is _{CaB 2 O 4, ZnB 2 O} 4 or the like.
Examples of the phosphorus compound include H ₃ PO ₄ , P ₂ O ₅ , and P. Li, Na, K, R
b and Cs.

As a method for producing a porcelain based on the present invention, for example, an oxide of Ba, Mg, W or a metal salt such as a hydroxide, a carbonate, a nitrate or the like which forms an oxide upon firing is used as a raw material. After these are weighed so as to be in the above-mentioned range, they are sufficiently mixed. Thereafter, the mixture is
Calcination is performed at 0 to 1300 ° C. To the obtained calcined product, for example, a boric acid compound such as B ₂ O ₃ , a phosphorus compound such as P ₂ O ₅ , and an alkali metal-containing compound such as SiO ₂ and Li ₂ CO _{3 in} a predetermined amount. The mixture is weighed, added and 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 placed in an oxidizing atmosphere such as air.
By firing at 00 to 1600 ° C., a dielectric porcelain can be obtained.

[0020]

In the dielectric ceramic composition of the present invention, BaO, Mg
Higher porcelain strength and Q than compositions comprising O, WO ₃
And the Q value is 4000 or more, and the temperature coefficient τf of the resonance frequency can be freely controlled in a certain region, and high strength can be realized by high porcelain density (bulk specific gravity). it can.

That is, by adding a predetermined amount of at least one of Sn, Mn, Ca and Group 3a, 4a elements of the periodic table to a composition comprising BaO, MgO, and WO ₃ , the temperature coefficient τf of the resonance frequency is increased. Can be shifted to the plus side. Further, by containing a predetermined amount of a boric acid compound, a phosphorus compound, SiO ₂ and an alkali metal-containing compound with respect to the main component, sintering is promoted, and high porcelain strength and Q value can be obtained.

[0022]

【Example】

Example 1 As raw materials, BaCO ₃ , MgCO ₃ ,
WO ₃ powder was weighed to a composition shown in Table 1 and wet-mixed in a ball mill for 20 hours using pure water as a medium. The mixture is then dried (dehydrated) and
Calcination was performed at 00 ° C. for 2 hours. B ₂ O ₃ in the calcined product, H ₃
Tables 2 to ₄ show PO ₄ , SiO ₂ and alkali metal-containing compounds.
4 was weighed so as to have the ratio shown in FIG. 4, and wet-mixed in a ball mill for 20 hours using isopropyl alcohol as a medium, and then paraffin wax was used as a binder.
After adding the weight%, it was dried and sized through a mesh.
Next, the sized product is 10 m in diameter at a pressure of about 1 ton / cm ^2.
m and 5 mm in thickness. Further, the molded body was fired in the atmosphere at 1400 to 1600 ° C. for 2 hours to obtain a dielectric ceramic.

The porcelain thus obtained is JIS standard C21
The bulk specific gravity was determined based on 41-1978 (Ceramic material evaluation test method for electrical insulation). In addition, both surfaces of the porcelain were flat-polished to prepare a sample for evaluation of dielectric properties (a cylindrical shape having a diameter of 8 mm and a thickness of 6 mm). Evaluation of the dielectric properties was performed using the above-described sample by a dielectric cylinder resonator method at a frequency of 10 GHz.
Was measured for relative permittivity and Q value. Also, -40 to 8
The resonance frequency in the temperature range of 5 ° 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 components.
The content of B, P, Si, and alkali metal added to the main component in the form of a predetermined compound, the bulk specific gravity, the relative dielectric constant, the Q value, and the temperature coefficient τf of the resonance frequency are shown.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

From these Tables 2 and 4, the main component 10
0 for 0 parts by weight, boric acid compound terms _of B ₂ O _3.
01 to 0.20 part by weight, phosphorus compound in an amount of 0.005 to 1 part by weight in terms of P, 0.01 to 1 part by weight in terms of SiO ₂ , and alkali metal-containing compound in carbonate By adding 0.01 parts by weight or more and less than 1 part by weight, or by adding these compounds in combination, the bulk specific gravity and the Q value are improved as compared with the composition composed of BaO, MgO, and WO _3. , Relative permittivity is 1
8 to 22, the Q value is 4800 or more, and the temperature coefficient τf of the resonance frequency has excellent characteristics within ± 30 ppm / ° C.

Example 2 As a raw material, BaCO ₃ , MgCO ₃ ,
WO ₃ and YO _3/2 , LaO _3/2 , CeO ₂ , NdO
Powders of _3/2 , PrO _11/6 and SmO _3/2 were weighed to the proportions shown in Tables 5 to 8 as main component raw materials, and wet-mixed in a ball mill for 20 hours using pure water as a medium. . Table 5 to Table 8
The main component No, in, is No, in Table 1. Next, the mixture was dried (dehydrated) and calcined at 1200 ° C. for 2 hours.
The calcined product in the _{B 2 O 3, H 3 PO} 4, SiO 2, alkali metal-containing compound were weighed so that the proportions shown in Tables 5 to 8, isopropyl alcohol - Le as a medium, ball - the mill After wet mixing for 20 hours, paraffin wax is added as a binder in an amount of 1 to 10% by weight and then dried.
It was sized through a mesh. Next, the sized product is added for about 1 ton.
/ Cm ^{2 at} a pressure of 10 mm in diameter and 5 mm in thickness. Further, the molded body is placed in the atmosphere at 1400 to 16
It was fired at 00 ° C. for 2 hours to obtain a dielectric porcelain.

With respect to the porcelain thus obtained, the bulk specific gravity, the relative dielectric constant, the Q value, and the temperature coefficient τf of the resonance frequency were determined in the same manner as in the first embodiment. Tables 5 to 8 show the results.

[0032]

[Table 5]

[0033]

[Table 6]

[0034]

[Table 7]

[0035]

[Table 8]

According to these Tables 5 to 8, BaO, Mg
By adding 0.1 to 30 mol parts of Group 3a element of the periodic table to 100 mol parts of the composition composed of O and WO ₃ , the temperature coefficient τf of the resonance frequency can be adjusted to an optimum value. I understand. By adding at least one of B, P, Si and an alkali metal element in a predetermined amount to 100 parts by weight of the main component, BaO, MgO, W
It can be seen that the bulk specific gravity and the Q value are improved, the relative dielectric constant is 18 to 22, and the Q value is 4300 or more, which is superior to the composition composed of O ₃ .

Example 3 As a raw material, BaCO ₃ , MgCO ₃ ,
WO ₃ and HfO ₂ , ZrO ₂ , MnCO ₃ , SnO
₂ , TiO ₂ , and CaCO ₃ powders were weighed at the ratios shown in Tables 9 to 11 as main component raw materials, and wet-mixed in a ball mill for 20 hours using pure water as a medium. Table 9 to Table 1
In No. 1, No. of the main component is No. in Table 1. Next, the mixture was dried (dehydrated) and calcined at 1200 ° C. for 2 hours. B ₂ O ₃ , H ₃ PO ₄ , Si
O ₂ and alkali metal-containing compounds were weighed so as to have the proportions shown in Tables 9 to 11 and wet-mixed in a ball mill for 20 hours using isopropyl alcohol as a medium, and then paraffin wax was used as a binder. After adding 1 to 10% by weight, the mixture was dried and sized through a mesh. Next, the sized product was dried at a pressure of about 1 ton / cm ² with a diameter of 10 mm and a thickness of 5 mm.
mm. Further, the molded body was fired in the atmosphere at 1400 to 1600 ° C. for 2 hours to obtain a dielectric ceramic. About the obtained porcelain, bulk specific gravity, relative permittivity, Q
The value and the temperature coefficient τf of the resonance frequency were determined in the same manner as in Example 1. Tables 9 to 11 show the results.

[0038]

[Table 9]

[0039]

[Table 10]

[0040]

[Table 11]

According to these Tables 9 to 11, BaO, M
S per 100 mole parts of the composition consisting of gO and WO ₃
n, Mn, Ca and Group 4a elements of the periodic table
It can be seen that by adding 20 mol parts, the temperature coefficient τf of the resonance frequency can be adjusted to an optimum value. Further, by adding at least one of B, P, Si and an alkali metal element in a predetermined amount to 100 parts by weight of the main component, the bulk specific gravity and the Q value are higher than those of a composition composed of BaO, MgO and WO _3. And the relative dielectric constant is 18 to 2
2. It can be seen that it has excellent characteristics in which the Q value is 4600 or more and the temperature coefficient τf of the resonance frequency is within ± 30 ppm / ° C.

[0042]

As described in detail above, according to the present invention, B
B, P, Si, and alkali metal elements are added to the main component consisting of aO, MgO, and WO ₃ or the main component containing Sn, Mn, Ca, and elements of Groups 3a and 4a in the periodic table. BaO, MgO, W
The bulk specific gravity is higher than that of the composition comprising O ₃ , the strength can be increased, the Q value at 10 GHz can be increased (4000 or more), and the temperature coefficient τf of the resonance frequency can be controlled. . In addition, Sn, M
By containing n and Ca and elements of Groups 3a and 4a of the periodic table, the sinterability can be improved, and the temperature coefficient τf of the resonance frequency can be shifted to the plus side to control the dielectric properties.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-309925 (JP, A) JP-A-6-236708 (JP, A) JP-A-5-205524 (JP, A) (58) Field (Int. Cl. ⁷ , DB name) C04B 35/00

Claims (12)

(57) [Claims] (1) at least Ba, Mg, W as a metal element;
When the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0. 40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 Based on 100 parts by weight of the main component satisfying x + y + z = 1.00, a boric acid compound is added in an amount of 0.01 to 0.2 parts by weight in terms of B ₂ O _3. A dielectric porcelain composition, comprising: 2. At least Ba, Mg, W as a metal element
When the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0. 40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 The phosphorus compound is added and contained in an amount of 0.005 to 1 part by weight based on 100 parts by weight of the main component satisfying x + y + z = 1.00. Dielectric porcelain composition. 3. At least Ba, Mg, W as a metal element
When the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0. 40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 With respect to 100 parts by weight of the main component satisfying the following condition, 0.01 to 1 part by weight of SiO ₂ is added and contained. Porcelain composition. 4. At least Ba, Mg, W as a metal element
When the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0. 40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 The alkali metal-containing compound is added to and contained in an amount of 0.01 to less than 1 part by weight in terms of carbonate with respect to 100 parts by weight of the main component satisfying x + y + z = 1.00. A dielectric porcelain composition characterized by the following. 5. At least Ba, Mg, W as a metal element
When the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0. 40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 With respect to 100 mol parts of the composition satisfying the following condition, the periodic table 3
The boric acid compound is used in an amount of 0.01 to 0.3 parts by weight in terms of B ₂ O ₃ with respect to 100 parts by weight of the main component containing 0.1 to 30 parts by mole of at least one element selected from group a elements. A dielectric porcelain composition, characterized in that it contains 2 parts by weight or less. 6. At least Ba, Mg, W as a metal element
When the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0. 40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 With respect to 100 mol parts of the composition satisfying the following condition, the periodic table 3
A phosphorus compound is added in an amount of 0.005 to 1 part by weight based on 100 parts by weight of a main component containing 0.1 to 30 parts by mole of at least one element selected from group a elements. A dielectric porcelain composition characterized by comprising: 7. At least Ba, Mg, W as a metal element
When the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0. 40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 With respect to 100 mol parts of the composition satisfying the following condition, the periodic table 3
SiO ₂ is added in an amount of 0.01 to 1 part by weight based on 100 parts by weight of a main component containing 0.1 to 30 parts by weight of at least one element selected from Group a elements. A dielectric porcelain composition characterized by the following. 8. At least Ba, Mg, W as a metal element
When the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0. 40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 With respect to 100 mol parts of the composition satisfying the following condition, the periodic table 3
0.01 parts by weight or more and 1 part by weight of an alkali metal-containing compound in terms of carbonate relative to 100 parts by weight of a main component containing at least one element selected from group a elements in a ratio of 0.1 to 30 parts by mole. A dielectric porcelain composition characterized by containing less than 10 parts by weight. 9. At least Ba, Mg, W as a metal element
When the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0. 40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 Sn, Mn,
A boric acid compound is contained in an amount of 0.01 part by weight in terms of B ₂ O ₃ with respect to a main component containing 0.1 to 20 mol parts of at least one element selected from Ca and elements of Group 4a of the periodic table. A dielectric porcelain composition characterized in that it is added in an amount of not less than 0.2 parts by weight. 10. At least Ba, Mg,
When W is contained and the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are: 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0 .40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 Sn, Mn,
0.005 parts by weight or more of a phosphorus compound in a P amount with respect to a main component containing 0.1 to 20 mol parts of at least one element selected from Ca and an element of Group 4a of the periodic table.
A dielectric porcelain composition, characterized in that it contains not more than parts by weight. 11. At least Ba, Mg,
When W is contained and the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are: 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0 .40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 Sn, Mn,
0.01 to 1 part by weight of SiO ₂ is added to the main component containing 0.1 to 20 parts by mole of at least one element selected from Ca and Group 4a element of the periodic table. A dielectric porcelain composition characterized by comprising: 12. At least Ba, Mg,
When W is contained and the composition formula based on the molar ratio of these components is expressed as xBaO · yMgO · zWO ₃ , x, y, and z are: 0.40 ≦ x ≦ 0.60 0.13 ≦ y ≦ 0 .40 0.20 ≦ z ≦ 0.30 x + y + z = 1.00 Sn, Mn,
With respect to the main component containing 0.1 to 20 mol parts of at least one element selected from the group consisting of Ca and Group 4a element of the periodic table, the alkali metal-containing compound is added in an amount of 0.1 to 20 mol parts in terms of carbonate.
A dielectric porcelain composition characterized by being added in an amount of not less than 01 parts by weight and less than 1 part by weight.