JPH1112032A - Dielectric ceramic composition and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of giving a ceramic free from any warpage or strain even in the case of being sintered simultaneously with a conductor predominant in Ag or Cu, and to obtain a laminate from the above composition. SOLUTION: This dielectric ceramic composition comprises 100 pts.wt. of the major component, a multiple oxide containing Mg, Ca and Ti as metallic elements, wherein the composition formula of the multiple oxide is shown as aMgO.bCaO.cTiO2 ((a), (b) and (c) satisfy the following relationships: 25.0<=(a)<=35.0, 0.3<=(b)<=7.0, 60.0<=(c)<=70.0, and (a+b+c)=100), 3-20 pts.wt. of a boron-contg. compound in terms of B2 O3 , 1-10 pts.wt. of an alkali metal- contg. compound in terms of the corresponding alkali metal carbonate, and a total of 0.2-6 pts.wt. of at least one kind among Sr-contg. compound, Al-contg. compound, Si-contg. compound, W-contg. compound, and Y-contg. compound, in terms of SrCO3 , Al2 O3 , SiO2 , WO3 , and Y2 O3 , respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric porcelain composition which can be fired at a low temperature and is applied to, for example, an electronic circuit board or an electronic component used in a high-frequency region, and includes, for example, a resonator, a capacitor, and a filter. And a laminated body having a conductor such as a substrate and an electronic component.

[0002]

2. Description of the Related Art Conventionally, various dielectric ceramics have been used as dielectric materials for electronic components such as resonators, capacitors, and filters. In recent years, with the development and spread of mobile communication such as mobile phones, demand for dielectric ceramics as materials for electronic circuit boards and electronic components has been increasing.

In the simultaneous firing of dielectric ceramics and internal conductors in electronic circuits and electronic parts, the firing temperature of conventional dielectric ceramics was as high as 1100 ° C. or higher. , Pt, Pd, W, Mo, etc. were used. These conductive materials having a high melting point have a large conduction resistance, so that the conventional electronic circuit board has a problem that the Q value of the resonance circuit and the inductance becomes small and the transmission loss of the conductor line becomes large.

[0004] In order to solve such a problem, there has been proposed a low-temperature-fired dielectric ceramic which can be co-fired with Ag, Cu or the like having a low conduction resistance. For example, the dielectric porcelain composition disclosed in Japanese Patent Application Laid-Open No. 8-208330, filed by the present applicant, contains MgO, CaO, and TiO _2.
And B ₂ O ₃ , Li ₂ CO ₃ , and 900
It can be fired simultaneously with an internal conductor such as Ag or Cu at a relatively low temperature of -1050 ° C, has a relative dielectric constant εr of 18 or more, a Q value at a measurement frequency of 7 GHz of 2,000 or more, and a temperature coefficient τf of a resonance frequency. Has excellent characteristics within ± 40, and can realize miniaturization and high performance of high-frequency electronic components.

[0005]

However, the dielectric porcelain composition disclosed in Japanese Patent Application Laid-Open No. 8-208330 has a high shrinkage onset temperature of 845 to 960 ° C. in sintering. The matching of the shrinkage behavior with the conductor material containing Ag or Cu as a main component at a low temperature is poor, and there is a problem that the fired substrate is warped or distorted.

That is, as the conductor, a conductor containing Ag and / or Cu as a main component, for example, Ag, Cu, or a glass component, a ceramic component,
There are materials to which metals such as t and Pd are added, and these conductors have a shrinkage onset temperature of 650 ° C. at the highest during firing.
Therefore, there is a large difference between the dielectric ceramic composition and the shrinkage start temperature of the dielectric ceramic composition, thereby causing a problem that the substrate is deformed.

[0007] The present invention has been made in view of the above problems,
By lowering the shrinkage start temperature of the dielectric porcelain composition, it is possible to approach the shrinkage start temperature of the conductor, and to obtain a porcelain free of warpage and distortion even when co-fired with a conductor containing Ag or Cu as a main component. It is an object of the present invention to provide a dielectric ceramic composition and a laminate that can be manufactured.

[0008]

The dielectric ceramic composition of the present invention is a composite oxide containing Mg, Ca, and Ti as metal elements, and has a composition formula based on the weight ratio of these metal element oxides. , when expressed as _{aMgO · bCaO · cTiO 2, a} , b, c is 25.0 ≦ a ≦ 35.0,0.3 ≦ b
≦ 7.0, 60.0 ≦ c ≦ 70.0, a + b + c = 10
0 to 3 parts to 20 parts by weight of a boron-containing compound in terms of B ₂ O _{3 based on} 100 parts by weight of the main component,
Alkali metal-containing compound is converted to alkali metal carbonate by 1
-10 parts by weight, Sr-containing compound, Al-containing compound, Si
At least one of the W-containing compound, the W-containing compound and the Y-containing compound is SrCO ₃ , Al ₂ O ₃ , Si
O _2, WO _3, is in terms _of Y ₂ O ₃ comprising a total of 0.2-6 parts by weight ones.

A composite oxide containing Mg, Ca, and Ti as metal elements, the composition formula of which is (100-
x) MgTiO ₃ -xCaTiO ₃ (where x represents a weight ratio and 1 ≦ x ≦ 15), and a boron-containing compound is added to B ₂ O with respect to 100 parts by weight of the main component. _Three
3 to 20 parts by weight in terms of conversion, 1 to 10 parts by weight of an alkali metal-containing compound in terms of alkali metal carbonate, at least one of Sr-containing compounds, Al-containing compounds, Si-containing compounds, W-containing compounds and Y-containing compounds Each Sr
It contains 0.2 to 6 parts by weight in total in terms of CO ₃ , Al ₂ O ₃ , SiO ₂ , WO ₃ and Y ₂ O ₃ .

[0010] The laminate of the present invention is a laminate having a conductor containing Ag and / or Cu as a main component inside and / or on a surface of a dielectric substrate formed by laminating a plurality of dielectric layers. The body layer is made of the above-mentioned dielectric ceramic composition.

[0011]

According to the dielectric porcelain composition of the present invention, 900 to 10
It can be fired at a relatively low temperature of 50 ° C. and has a relative dielectric constant ε
The r and Q values are high, and the temperature coefficient τf of the resonance frequency can be made relatively small, so that the laminated body (high-frequency electronic circuit board or electronic component) can be reduced in size and improved in performance.

And, in the dielectric ceramic composition of the present invention,
Sr-containing compound, Al-containing compound, Si-containing compound, W
And at least one of the Y-containing compound and SrCO ₃ , Al ₂ O ₃ , SiO ₂ , WO ₃ ,
Since a total of 0.2 to 6 parts by weight in terms of Y ₂ O _{3 is} contained, the shrinkage onset temperature in the sintering process can be lowered to 815 ° C. or less, and the shrinkage onset temperature of the conductor can be brought close to the substrate. In an electronic component, even when co-fired with a conductor containing Ag and Cu as main components, it is possible to suppress occurrence of warpage, distortion, and the like of a substrate or the like.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The dielectric ceramic composition of the present invention is a composite oxide containing Mg, Ca and Ti as metal elements, and the composition formula based on the weight ratio of these metal element oxides is aMgO · When expressed as bCaO · cTiO ₂ , a,
b and c are 25.0 ≦ a ≦ 35.0, 0.3 ≦ b ≦ 7.
0, 60.0 ≦ c ≦ 70.0, a + b + c = 100, 100 parts by weight of the main component, the boron-containing compound is ₃ to 20 parts by weight in terms of B ₂ O ₃ , and the alkali metal-containing compound is alkali. 1 to 10 parts by weight in terms of metal carbonate, at least one of Sr-containing compound, Al-containing compound, Si-containing compound, W-containing compound and Y-containing compound is SrCO ₃ , Al ₂ O ₃ , SiO ₂ , WO ₃ , Y ₂ O
_It contains 0.2 to 6 parts by weight in total in ₃ conversion.

In the present invention, the weight ratio a of MgO in the composition formula is 25 ≦ a ≦ 35, and the weight ratio b of CaO is 0.
The reason why 3 ≦ b ≦ 7 is that the weight ratio a of MgO is 25% by weight.
If the ratio is less than 0% or if the weight ratio b of CaO exceeds 7% by weight, the temperature coefficient τf of the resonance frequency becomes too large. Conversely, when the weight ratio a of MgO exceeds 35% by weight or the weight ratio b of CaO is less than 0.3% by weight, the temperature coefficient τf of the resonance frequency becomes too large. . Therefore, the weight ratio a of MgO and the weight ratio b of CaO are 25.0 ≦ a ≦ 35.0,
0.3 ≦ b ≦ 7.0, and especially from the viewpoint of the temperature coefficient τf of the resonance frequency of the dielectric ceramic, 28.0 ≦ a ≦
34.0, preferably 0.4 ≦ b ≦ 6.5.

Further, the weight ratio c of TiO ₂ is set to 60 ≦ c ≦
The reason for setting it to 70 is that when the weight ratio c of TiO ₂ is less than 60% by weight or more than 70% by weight, the Q value decreases. Therefore, the weight ratio c of TiO ₂ is 60 ≦ c ≦ 7.
0 from the viewpoint of the Q value of the dielectric porcelain.
4 ≦ c ≦ 68 is preferred.

The starting materials are MgTiO ₃ and CaTi
By using O ₃ , the Q value is further improved, and the control of the temperature coefficient becomes easy. That is, (100-x) MgT
_{3 to} 20 parts by weight of a boron-containing compound in terms of B ₂ O ₃ with respect to 100 parts by weight of a main component represented by iO ₃ -xCaTiO ₃ (where x represents a weight ratio and 1 ≦ x ≦ 15) Parts, 1 to 10 parts by weight of an alkali metal-containing compound in terms of alkali metal carbonate, an Sr-containing compound, an Al-containing compound,
At least one of the Si-containing compound, the W-containing compound and the Y-containing compound is SrCO ₃ , Al ₂ O ₃ ,
This is a case where the total content is 0.2 to 6 parts by weight in terms of SiO ₂ , WO ₃ , and Y ₂ O ₃ .

Here, the weight ratio of CaTiO _{3 in} the main component is set to 1 ≦ x ≦ 15 because the weight ratio of CaTiO ₃ is 1
If the weight ratio is less than 15% by weight, the temperature coefficient τf of the resonance frequency greatly shifts to the minus side, and the weight ratio is 15% by weight.
Is exceeded, the temperature coefficient τf of the resonance frequency is greatly shifted to the plus side. Therefore, the weight ratio x of CaTiO ₃ is specified to be 1 to 15% by weight, and in particular, from the viewpoint of the temperature coefficient τf of the resonance frequency of the dielectric porcelain, 1 to 10%.
% By weight is preferred.

In the present invention, the boron-containing compound is added in an amount of ₃ to 20 in terms of B ₂ O _{3 based on} 100 parts by weight of the main component.
Parts, 1 to 10 parts by weight of alkali metal-containing compound in said alkali metal carbonate terms, Sr-containing compound, Al-containing compound, Si-containing compounds, W-containing compound and Y at least one of each of the containing compounds SrCO _3, Al ₂
O ₃ , SiO ₂ , WO ₃ , Y ₂ O ₃ conversion: 0.2 to total
It contains 6 parts by weight.

Thus, for 100 parts by weight of the main component,
The boron-containing compound was added 3 to 20 parts by weight terms _of B ₂ O ₃ is 1 if the added amount of B ₂ O ₃ is less than 3 parts by weight
This is because sintering does not occur even at 100 ° C., and simultaneous sintering with Ag or Cu cannot be performed. Conversely, if the amount exceeds 20 parts by weight, the crystal phase changes and the Q value decreases. Therefore, the addition amount of the boron-containing compound is 3 to _{3 in} terms of B ₂ O _{3 with} respect to the main component.
The specific amount is specified as 20 parts by weight, and particularly, from 3 to 9 parts by weight is desirable from the viewpoint of the Q value of the dielectric porcelain. Examples of boron-containing compounds include metallic boron, B ₂ O ₃ , colemanite, CaB ₂ O
There are ₄ magnitudes.

The reason why the alkali metal-containing compound is added in an amount of 1 to 10 parts by weight in terms of the alkali metal carbonate is that when the addition amount of the alkali metal-containing compound, for example, lithium-containing compound is less than 1 part by weight, 1100 ° C. But without sintering
Simultaneous firing with Ag or Cu is no longer possible.
If the amount exceeds 0 parts by weight, the crystal phase changes and the Q value decreases. Therefore, the addition amount of the alkali metal-containing compound is specified to be 1 to 10 parts by weight in terms of alkali metal carbonate, for example, in terms of Li ₂ CO ₃ , based on 100 parts by weight of the main component. From 3 to 7
Parts by weight are desirable.

Examples of the alkali metal include Li, Na and K. Among them, Li is particularly desirable.
Examples of the alkali metal-containing compound include the above-mentioned alkali metal carbonates and oxides.

In the dielectric porcelain composition of the present invention, the main component 1
Further, at least one of Sr-containing compound, Al-containing compound, Si-containing compound, W-containing compound and Y-containing compound was added to SrCO ₃ , Al
₂ O ₃ , SiO ₂ , WO ₃ , Y ₂ O ₃ conversion, total 0.2
-6 parts by weight. If the content is less than 0.2 parts by weight, the shrinkage start temperature in the sintering process of the dielectric ceramic is as high as about 840 ° C., and the effect of addition cannot be obtained. On the other hand, when the additive exceeds 6 parts by weight,
This is because the relative permittivity εr or Q value of the dielectric porcelain decreases. From the viewpoint of the relative permittivity εr or Q value of the dielectric ceramic, a total of 0.7 to 4 parts by weight is desirable.

In the present invention, oxides such as Si, Zn, Mn, and Zr may be added and contained as long as the dielectric properties are not adversely affected. In this case, firing at a lower temperature is possible.

The dielectric porcelain composition of the present invention may be, for example,
Each raw material powder of gCO ₃ , CaCO ₃ , and TiO ₂ was weighed so as to have a predetermined amount, mixed and pulverized.
Calcination is performed in air at a temperature of 300 ° C. for 1 to 3 hours. To the obtained calcined material, for example, each powder of B ₂ O ₃ and Li ₂ CO ₃ ,
And SrCO ₃ , Al ₂ O ₃ , SiO ₂ , WO ₃ , Y
_At least one kind of powder of ₂ O ₃ is weighed to a predetermined amount, mixed and pulverized, formed into a predetermined shape by a known method such as press molding or a doctor blade method, and then oxidized atmosphere such as in the air or 0.5 to 2.degree. C. at 900 to 1050.degree. C. in a non-oxidizing atmosphere such as a nitrogen atmosphere.
It is obtained by firing for 0 hours.

Further, the laminate of the present invention has a structure in which a dielectric substrate formed by laminating a plurality of dielectric layers has A
It has a conductor containing g and / or Cu as a main component, and uses the above-described dielectric ceramic composition as a dielectric layer.

As the conductor, one containing Ag and / or Cu as a main component, for example, Ag, Cu, or A
g, Cu, glass component or ceramic component, Pt,
A material to which a metal such as Pd is added is also included. A conductor obtained by adding a glass component or a ceramic component to these metals is suitably used as an internal conductor, and a conductor obtained by adding Pt is suitably used as a surface conductor. Such a conductor has a shrinkage onset temperature of at most about 650 ° C. during firing.

The dielectric porcelain composition of the present invention comprises at least one of an Sr-containing compound, an Al-containing compound, a Si-containing compound, a W-containing compound and a Y-containing compound.
By containing rCO ₃ , Al ₂ O ₃ , SiO ₂ , WO ₃ , and Y ₂ O ₃ in a total amount of 0.2 to 6 parts by weight, the shrinkage starting temperature can be 815 ° C. or less, so that the conductor shrinks. The starting temperature can be approached.

[0028]

【Example】

Example 1 First, MgCO ₃ , CaCO ₃ , Ti with a purity of 99% or more
Each raw material powder of O ₂ was weighed to the amount shown in Tables 1 to 3, and pure water was added as a medium to the raw material powder, and Z was added for 24 hours.
After mixing in a ball mill using rO ₂ balls, the mixture is dried and then the dried
Calcination was performed at a temperature of 0 ° C. for 1 hour.

B ₂ O ₃ , Li ₂ C
O ₃ , SrCO ₃ , Al ₂ O ₃ , SiO ₂ , WO ₃ , Y
The powder of ₂ O ₃ was weighed so as to have a ratio shown in Tables 1 to 3 and mixed for 24 hours in the above-mentioned ball mill, and then 1% by weight of polyvinyl alcohol was added as a binder, followed by granulation. Was press-formed at a pressure of about 1 t / cm ² to produce a columnar molded body having a diameter of about 12 mm and a height of 10 mm.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

Thereafter, the molded body was heated at a temperature of 400 ° C. for 4 hours in the air to remove the binder, and then calcined at a temperature shown in Tables 4 to 6 for 60 minutes in the air. Both end faces of the obtained cylindrical body were polished to prepare a sample for dielectric property evaluation.

The evaluation of the dielectric characteristics is performed by using the above-mentioned sample for evaluation and setting the resonance frequency to 6 to 8 G by the dielectric cylinder resonator method.
Hz, and the relative dielectric constant εr of each sample and 1 / tan δ at 7 GHz, that is, the Q value were measured.
Temperature coefficient τ of resonance frequency in the temperature range of ~ + 85 ° C
f was measured.

[0035]

[Table 4]

[0036]

[Table 5]

[0037]

[Table 6]

According to Tables 4 to 6, in the dielectric ceramic composition of the present invention, the onset temperature of shrinkage in the sintering process is 815 ° C.
Hereinafter, the firing temperature is relatively low at 900 to 1050 ° C., the relative dielectric constant εr is 18 or more, the Q value at 7 GHz is 2000 or more, and the temperature coefficient τf of the resonance frequency.
It can be understood that excellent characteristics within ± 40 can be obtained. Samples Nos. 15 and 16 used Na ₂ CO ₃ instead of Li ₂ CO ₃ .

Example 2 First, raw material powders of MgTiO ₃ and CaTiO _{3 having} a purity of 99% or more were weighed to the amounts shown in Tables 7 and 8, and pure water was added to the raw material powder for 24 hours. , ZrO ₂
After mixing in a ball mill using a ball, the mixture is dried, and then the dried product is dried at 1200 ° C. in air for 1 hour.
It was calcined for hours.

B ₂ O ₃ , Li ₂ C
O ₃ , SrCO ₃ , Al ₂ O ₃ , SiO ₂ , WO ₃ , Y
The powder of ₂ O ₃ was weighed so as to have the ratios shown in Tables 7 and 8, and mixed in the ball mill for 24 hours. Then, 1% by weight of polyvinyl alcohol was added as a binder, and the mixture was granulated. Was press-formed at a pressure of about 1 t / cm ² to produce a columnar molded body having a diameter of about 12 mm and a height of 10 mm.

[0041]

[Table 7]

[0042]

[Table 8]

Thereafter, the molded body was heated at 400 ° C. for 4 hours in the air to remove the binder, and then calcined at the temperatures shown in Tables 9 and 60 for 60 minutes in the air. Both end surfaces of the thus obtained cylindrical body were polished to obtain a dielectric property evaluation sample. The dielectric properties were evaluated in the same manner as described above, and the results are shown in Tables 9 and 10.

[0044]

[Table 9]

[0045]

[Table 10]

According to Tables 9 and 10, in the dielectric ceramic composition of the present invention, the shrinkage starting temperature in the sintering process is 8
The temperature is relatively low, such as 15 ° C. or less, and the firing temperature is 1050 ° C. or less, and the relative dielectric constant εr is 18 or more and the Q value is 300
It can be seen that it has excellent characteristics in which the temperature coefficient τf of the resonance frequency is 0 or more and within ± 30.

[0047]

According to the dielectric porcelain composition of the present invention, the onset temperature of shrinkage in the sintering process can be close to the shrinkage onset temperature of the conductor at 815 ° C. or less, and the firing temperature can be as low as 10 ° C.
Since the temperature is relatively low, such as 50 ° C. or lower, a laminate (substrate or electronic component) that can be fired simultaneously with Ag, Cu, or the like and has no warpage or distortion even when fired simultaneously can be obtained.

Further, it has a high relative dielectric constant (18 or more) in a high frequency region and a Q value (2,000 or more).
It is also excellent in temperature characteristics of resonance frequency (within ± 40), and further downsizing and high performance of high frequency electronic circuit boards and electronic components can be realized.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiro Hisa 1-4-4 Yamashita-cho, Kokubu-shi, Kagoshima Inside the Kyocera Research Institute

Claims (4)

[Claims] 1. A Mg as the metal element, Ca, a composite oxide containing Ti, when expressed as aMgO · bCaO · cTiO ₂ the formula by weight ratio of the metal element oxides, wherein a, b and c satisfy 25.0 ≦ a ≦ 35.0 0.3 ≦ b ≦ 7.0 60.0 ≦ c ≦ 70.0 a + b + c = 100 and 100 parts by weight of the main component ,
The boron-containing compound is ₃ to 20 parts by weight in terms of B ₂ O ₃ , and the alkali metal-containing compound is 1 to 1 parts in terms of alkali metal carbonate.
0 parts by weight, at least one of Sr-containing compound, Al-containing compound, Si-containing compound, W-containing compound and Y-containing compound is SrCO ₃ , Al ₂ O ₃ , Si
_{O 2, WO 3, Y 2} O 3 dielectric ceramic composition characterized in total 0.2 to 6 by containing parts by weight basis. 2. A composite oxide containing Mg, Ca, and Ti as metal elements, the composition formula of which is (100-x) M
gTiO ₃ -xCaTiO ₃ (where x represents a weight ratio and 1 ≦ x ≦ 15);
₃ to 20 parts by weight of the boron-containing compound in terms of B ₂ O ₃ , 1 to 10 parts by weight of the alkali metal-containing compound in terms of alkali metal carbonate, Sr-containing compound, Al
At least one of the containing compound, the Si-containing compound, the W-containing compound and the Y-containing compound is SrCO ₃ ,
_{Al 2 O 3, SiO 2,} WO 3, Y 2 O 3 dielectric ceramic composition characterized in total 0.2 to 6 by containing parts by weight basis. 3. A laminate having a conductor containing Ag and / or Cu as a main component inside and / or on a surface of a dielectric substrate formed by laminating a plurality of dielectric layers. Item 10. A laminate comprising the dielectric ceramic composition according to Item 1. 4. A laminate having a conductor containing Ag and / or Cu as a main component inside and / or on a surface of a dielectric substrate formed by laminating a plurality of dielectric layers. Item 3. A laminate comprising the dielectric ceramic composition according to Item 2.