JP2001010858A - Composition for ceramic substrate and ceramic circuit component - Google Patents

Abstract

(57) [Summary] A low-temperature sintering of 1000 ° C. or less is possible, and a conductor circuit mainly composed of a low-resistance metal such as an Ag-based or Cu-based metal can be simultaneously fired to form a dense sintered body. Obtainable,
A composition for a ceramic substrate is provided. SOLUTION: The composition for a ceramic substrate contains, by weight ratio, 25 to 34% of glass powder and 66 to 75% of ceramic powder, respectively, and the ceramic powder is composed of fine particles and coarse particles having mutually different particle diameters. It is composed of at least two kinds of particles, the average particle diameter of the combined fine particles and coarse particles is less than 1 μm, and the average particle diameter of the glass powder is 1 μm
Is less than. According to this composition, the dispersibility of glass and ceramic is good, and a dense sintered body can be obtained at a firing temperature of 1000 ° C. or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for a ceramic substrate and a ceramic circuit component, and more particularly to a composition for a ceramic substrate which can be sintered at a low temperature of 1000.degree. The present invention relates to ceramic circuit components such as multilayer integrated circuit components and thick film hybrid circuit components.

[0002]

2. Description of the Related Art At present, the mainstream of ceramic substrates is an alumina substrate. However, in order to obtain an alumina substrate, it must be fired at a high temperature of about 1600 ° C.,
When, for example, a multilayer circuit component is formed using an alumina substrate, a metal having a high melting point must be used for the internal conductor. However, a high melting point metal is generally not suitable as a conductor for a multilayer circuit component whose frequency and speed are increasing because of its high resistance.

[0003] Therefore, Au, Ag, Ag-Pd, Ag-
Attention has been paid to glass-ceramic substrates having a firing temperature of 1000 ° C. or less, which enable use of low-resistance metals such as Pt and Cu as internal conductors, and various developments have been made.

For example, Japanese Patent Publication No. 3-53269 discloses that 50 to 64% of glass powder and 50 to 35% by weight are used.
% Al ₂ O ₃ powder and mixed at 800-1000 ° C.
A low-temperature sintered ceramic substrate that can be sintered at is described.

[0005]

However, in the case of a substrate having the above-mentioned glass charge amount of 50% or more, the crystal ratio in the fired substrate is low, and the reliability of the mechanical characteristics of the substrate is low. There is a problem.

Accordingly, an object of the present invention is to provide a composition for a ceramic substrate and a ceramic circuit component formed using the same, which can solve the above-mentioned problems.

More specifically, according to the present invention, A
Provided is a composition for a ceramic substrate for an electronic circuit having a firing temperature of 1000 ° C. or lower, which enables a low-resistance metal such as u, Ag, Ag-Pd, Ag-Pt, or Cu to be used as an internal conductor. According to the ceramic substrate obtained by firing this composition, it is possible to realize a transverse rupture strength exceeding 370 MPa.

[0008]

In order to solve the above-mentioned technical problems, the composition for a ceramic substrate according to the present invention comprises, by weight, 25 to 34% of glass powder and 66 to 75% of ceramic powder. Each containing, the ceramic powder is composed of at least two kinds of fine particles and coarse particles having mutually different average particle diameters, the average particle diameter of the total of the fine particles and the coarse particles is less than 1 μm, The particle size is less than 1 μm.

As described above, in the composition for a ceramic substrate according to the present invention, the particle size of the ceramic powder and the particle size of the glass powder are increased while the proportion of the ceramic is increased, as compared with the above-described prior art. The control is intended to increase the mechanical strength of the ceramic substrate obtained by sintering the composition.

Generally, the driving force for sintering in a composite material consisting of glass and ceramic is provided by softening and viscous flow of glass. Therefore, when the proportion of ceramic is increased and the proportion of glass is decreased, the glass around the ceramic particles becomes insufficient, and the sinterability and mechanical strength decrease.

According to the present invention, not only the ratio of the ceramic is increased, but also the fine particles and the coarse particles are combined while the ceramic powder is composed of at least two types of fine particles and coarse particles having different average particle diameters. Has an average particle size of less than 1 μm, and the glass powder has an average particle size of 1
When the thickness is less than μm, the packing property of the ceramic is improved. Therefore, the remaining volume excluding the volume of the ceramic part is reduced from the volume of the sintered body of the composite material composed of glass and ceramic, and even if the amount of glass is relatively small, this effectively surrounds the ceramic particles. Can be covered, so that
A decrease in sinterability can be prevented. If the relative density after sintering is substantially the same, the mechanical strength is increased as the proportion of ceramic increases.

In the present invention, preferably, as the glass powder, a glass powder made of glass having a softening temperature of 800 ° C. or lower and low reactivity with ceramic is used.

Preferably, the ceramic powder contains an alumina powder.

As described above, when the ceramic powder contains alumina powder, the glass constituting the glass powder is:
28-64 wt% of SiO _2, 0 to 30 wt% of B ₂ O
₃ , 0 to 30% by weight of Al ₂ O ₃ and 36 to 50% by weight of RO (where R is Mg, Ca, Sr and B
a at least one selected from a).

In the above case, the glass constituting the glass powder is made of SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ and RO.
With respect to 100 parts by weight of the total of the above, further contains at least 5 parts by weight of an oxide of at least one alkali metal selected from Li ₂ O, K ₂ O and Na ₂ O, TiO ₂ , ZrO ₂ , Cr ₂ O ₃ , C
At least one compound selected from aF ₂ and CuO may be further contained at a content of 5 parts by weight or less.

In the present invention, preferably, the average particle diameter of the fine particles in the ceramic powder is 0.1 to 0.1.
8 μm, and the average particle size of the coarse particles is 0.2 to 3.0 μm.
m.

The ratio of the fine particles to the coarse particles in the ceramic powder is preferably 30 to 7
0% by weight, and 70 to 30% by weight of coarse particles.

The present invention also provides a ceramic circuit component comprising a substrate obtained by molding and firing the above-described composition for a ceramic substrate, and a conductor circuit formed in connection with the substrate. Is also directed.

In the ceramic circuit component, the conductor circuit preferably contains at least one metal selected from Ag, Au and Cu as a main component.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a composition for a ceramic substrate which can be fired at a low temperature and contains a glass powder and a ceramic powder.
4%, and 66-75% of ceramic powder, respectively. The reason for limiting to such a content ratio is as follows.

If the glass powder is less than 25% and the ceramic powder is more than 75%, the glass cannot sufficiently cover the ceramic particles, and a dense sintered body cannot be obtained.
On the other hand, when the glass powder is more than 34% and the ceramic powder is less than 66%, the mechanical strength is 370 MPa even though the obtained sintered body is dense, since the ratio of glass is large.
Below a, the reliability of the mechanical properties of the ceramic substrate is insufficient.

The composition of the glass constituting the glass powder is not particularly limited, but a glass having a softening temperature of 800 ° C. or lower and a low reactivity with ceramic is preferred.

As the ceramic powder, for example, alumina powder is advantageously used, and when alumina powder is used, the glass constituting the glass powder is as follows:
It is preferable to have the following composition.

That is, the glass is 28 to 64% by weight.
SiO_Two, 0-30% by weight of B_TwoO _Three0-30% by weight
Al_TwoO_Three, And 36-50% by weight of RO (only
And R is a small number selected from Mg, Ca, Sr and Ba.
At least one).

In the above glass composition, Si
O ₂ forms the skeleton of glass. If the content of SiO ₂ is less than 28% by weight, the softening point of the glass becomes too low, and the heat resistance of the obtained ceramic substrate may deteriorate. On the other hand, if it exceeds 64% by weight, the softening point of the glass becomes too high, and it becomes difficult to fire at a temperature of 1000 ° C. or less to obtain a ceramic substrate. As a result, Au, Ag, Cu, etc. May not be used as a conductive component for forming

B ₂ O ₃ has the effect of lowering the firing temperature for obtaining a ceramic substrate, but if its content exceeds 30% by weight, water resistance and chemical resistance deteriorate, and In a high-temperature, high-humidity environment, the quality of the ceramic substrate may be altered, and the softening point of the glass may be too low, resulting in poor heat resistance of the obtained ceramic substrate.

Al ₂ O ₃ stabilizes the glass structure,
It has the effect of improving the heat resistance of the obtained ceramic substrate, but if its content exceeds 30% by weight, the softening and fluidity of the glass deteriorate, and the ceramic substrate is sintered at 1000 ° C. or lower. In some cases, crystallization of the glass is hindered, and characteristics such as high mechanical strength and low loss cannot be realized.

RO has the effect of promoting the softening and fluidity of glass, but its content is 36% by weight.
If it is less, the softening point of the glass becomes too high, and it becomes difficult to fire at a temperature of 1000 ° C. or less to obtain a ceramic substrate. As a result, Au, Ag, Cu, etc. You may not be able to use it. On the other hand, when the content of RO exceeds 50% by weight, the glass structure becomes unstable, and a glass having stable quality may not be obtained.

Glass having the above preferred composition
In, Li_TwoO, K_TwoO and Na_TwoSelected from O
The at least one alkali metal oxide
O_Two, B _TwoO_Three, Al_TwoO_ThreeAnd total amount of RO 100
5 parts by weight or less based on parts by weight
Reduces the softening point of the glass and promotes fluidization
Has made it possible to increase the proportion of ceramics.
As a result, the mechanical strength of the obtained ceramic substrate is reduced.
It is possible to make it even higher.

Further, the glass having this preferred composition
TiO2_Two, ZrO_Two, Cr _TwoO_Three, CaF_TwoYou
At least one compound selected from the group consisting of
iO _Two, B_TwoO_Three, Al_TwoO_ThreeAnd the total amount of RO 10
0 parts by weight and not more than 5 parts by weight
The crystallization of the glass is accelerated and the resulting ceramic
To further increase the mechanical strength and Q value of the substrate
Will be possible.

The ceramic powder contained in the composition for a ceramic substrate according to the present invention is composed of at least two kinds of fine particles and coarse particles having different particle diameters, and the average particle size of the fine particles and the coarse particles is combined. The diameter is less than 1 μm, and the average particle size of the glass powder is less than 1 μm. The reason for limiting to such a particle size is as follows.

If the average particle size of the fine particles and the coarse particles in the ceramic powder is 1 μm or more, high dispersion between the ceramic and the glass is difficult, and the molding density of the composite material composed of the glass and the ceramic is reduced. Therefore, the sintered body obtained by firing, that is, the ceramic substrate has a low sintered density, and the mechanical strength becomes 370 MPa or less.

Even if both the average particle diameter of the ceramic powder and the average particle diameter of the glass powder are less than 1 μm, if the ceramic powder is not composed of at least two kinds of particles, fine particles and coarse particles, The packing properties of the powder are deteriorated, the ceramic cannot be sufficiently covered with the glass, and the molding density of the composite material composed of the glass and the ceramic also decreases. For this reason, the sintered body obtained by firing, that is, the sintered density of the ceramic substrate becomes low, and the mechanical strength becomes 370 MPa or less.

The average particle size of the ceramic powder is 1 μm.
Even if the average particle size of the glass powder is 1 μm or more, even if the ceramic powder is composed of at least two types of particles of fine particles and coarse particles, the ceramic particles can be sufficiently covered with glass. I ca n’t,
Therefore, the sintered body obtained by firing, that is, the sintered density of the ceramic substrate becomes low, and the mechanical strength becomes 370 MPa.
It is as follows.

The average particle size of each of the fine particles and the coarse particles in the ceramic powder is not particularly limited, but the average particle size of the fine particles is 0.1 to 0.8 μm.
It is preferable that the coarse particles have an average particle size of 0.2 to 3.0 μm.

The composition ratio of the fine particles and the coarse particles in the ceramic powder is not particularly limited, but is preferably selected so that the fine particles are 30 to 70% by weight and the coarse particles are 70 to 30% by weight.

The above-described composition for a ceramic substrate is used to produce a ceramic circuit component comprising a substrate obtained by molding and firing the same, and a conductor circuit formed in connection with the substrate. It is advantageously used for:

FIG. 1 is a sectional view schematically showing a ceramic multilayer circuit component 1 according to an embodiment of the present invention, which is an example of the above-described ceramic circuit component. The ceramic multilayer circuit component 1 is, roughly speaking, a ceramic substrate 2
And a conductor circuit 3 formed inside and / or on the surface of the ceramic substrate 2.

The ceramic substrate 2 is obtained by firing a ceramic molded body obtained by laminating a plurality of green sheets containing the composition for a ceramic substrate having the above-described composition. It comprises a plurality of ceramic layers 4 resulting from the firing of each of the green sheets.

The conductor circuit 3 is formed, for example, by simultaneously firing a conductive paste containing a conductive component containing at least one metal selected from Ag, Au and Cu as a main component at the same time as the above-mentioned ceramic molded body. It was done. The conductor circuit 3 includes, for example, external conductors 5, 6, and 7 formed on the surface of the ceramic substrate 2, and includes the internal conductor 8 formed on the inside of the ceramic substrate 2, for example. , 9,10,11
And via hole connection part 1
3, 14, 15, 16, 17, 18, and 19, and the like.

The internal conductors 8 and 9 are opposed to each other via a specific ceramic layer 4 to form a capacitor section 20. Also, via-hole connection portions 16 to 19 and internal conductor 1
0 to 12 are connected alternately and sequentially to form the inductor unit 21.

[0042]

EXPERIMENTAL EXAMPLES Hereinafter, the composition for a ceramic substrate according to the present invention will be described more specifically based on experimental examples.

Table 1 shows the composition of the composition for a ceramic substrate produced in this experimental example.

[0044]

[Table 1]

In Table 1, 45% by weight of glass was used.
SiO ₂ , 10 wt% B ₂ O ₃ , 5 wt% Al ₂
One having a composition containing O ₃ and 40% by weight of CaO was used. Therefore, a mixture of oxides or carbonates weighed to have such a composition was melted at a temperature of 1500 ° C., vitrified, quenched in water, and the quenched glass is shown in Table 1. The powder was pulverized to a particle size to produce glass powders having various particle sizes.

On the other hand, alumina powder, forsterite powder and zirconia powder having respective particle diameters of 0.4 μm, 0.9 μm and 1.4 μm as shown in Table 1 were prepared as ceramic powders.

Next, the glass powder and the ceramic powder prepared as described above were prepared at various ratios as shown in Table 1. Here, for the glass powder,
As shown in Table 1, various types of particle diameters are used, and as for the ceramic powder, as shown in Table 1, a material consisting of alumina is basically used, and for a specific sample, forsterite or zirconia is used. Was added thereto, and those having various particle sizes were mixed at a predetermined ratio.

The glass powder and the ceramic powder prepared as described above are mixed with a solvent (ethanol / toluene).
And a dispersant (sorbitan ester), and the mixture was dispersed. A binder (butyral resin) and a plasticizer (dioctyl phthalate) were added and mixed to obtain a slurry. Next, a green sheet was obtained by applying a doctor blade method to the slurry.

Next, based on the green sheets of the respective samples obtained as described above, several types of samples were prepared, and as shown in Table 2, “bending strength”, “dielectric constant” and "Q" was evaluated respectively.

[0050]

[Table 2]

First, a predetermined number of green sheets for each sample are laminated, cut into a predetermined size, and then fired at a firing temperature shown in Table 2 to obtain a sintered body. The dimensions were 36 mm, width 4 mm and thickness 3 mm. The sintered body according to each sample obtained in this manner was subjected to the JIS standard (JIS R160
The bending strength (three-point bending) was measured according to 1).

Further, a ceramic multilayer circuit component 1 as shown in FIG. 1 was manufactured using the green sheets of each sample. That is, a hole is formed in the green sheet, and an Ag-based paste is filled in these holes to form via-hole connection portions 13 to 1.
9 is formed, and an Ag-based paste is screen-printed to form a predetermined pattern of the outer conductors 5 to 7 and the inner conductors 8 to
No. 12 was formed. Thereafter, a predetermined number of these green sheets to become the ceramic layers 4 were laminated and pressed. Next, firing was performed at a firing temperature shown in Table 2 in air to produce a ceramic multilayer circuit component 1.

The frequency of 1 M is applied between the outer conductors 5 and 6 in the ceramic multilayer circuit component 1 thus obtained.
A voltage of Hz was applied to measure the capacitance and Q of the capacitor unit 20 to calculate the dielectric constant (ε _r ). The dielectric constant and Q are shown in Table 2.

In Tables 1 and 2, Samples 1 to 7
Samples 8 to 16 correspond to the examples within the scope of the present invention.
This corresponds to a comparative example outside the scope of the present invention.

Referring to Table 2, samples 1 to 5 as examples were used.
According to No. 5, when the firing temperature is 1000 ° C. or lower, 37
It has a flexural strength exceeding 0 MPa and a dielectric constant of 8.
6 to 8.8, and Q was 1700 to 2000, indicating sufficient characteristics as a ceramic substrate in a ceramic circuit component.

According to Samples 6 and 7 using a mixed powder of alumina powder and forsterite powder and a mixed powder of alumina powder and zirconia powder, respectively, as the ceramic powder, the firing temperature was 1000 ° C. or lower. The flexural strength exceeded 370 MPa, the dielectric constant was 8.5 to 8.8, and Q was 1500 to 1900. Similarly, the ceramic substrate showed sufficient characteristics as a ceramic substrate.

On the other hand, according to Sample 8 as a comparative example, since the proportion of alumina powder as the ceramic powder was small, the sintered density was high, but the transverse rupture strength was 370.
MPa or less.

According to Sample 9, since the ratio of the alumina powder as the ceramic powder was large, the molding density and thus the sintering density were low, and the bending strength was 370 MPa or less.

According to Samples 10 to 12, since the particle size of the alumina powder as the ceramic powder was large, the molding density and, consequently, the sintering density were low, and the flexural strength was 370M.
Pa or less. In particular, when the particle size of the alumina powder is 1.2
In Samples 11 and 12 having a size of not less than μm, Q was further reduced because the density of the ceramic substrate was further reduced.

Further, according to Samples 13 to 15, since the particle size of the glass powder is large, the glass cannot sufficiently cover the periphery of the ceramic particles, the molding density and thus the sintered density are low, and the bending strength is low. It became 370 MPa or less. In particular, Sample 14 in which the particle size of the glass powder is 1.2 μm or more
In Nos. 15 and 15, Q was lower because the density of the ceramic substrate was lower.

According to Sample 16, since the alumina powder as the ceramic powder was not composed of fine particles and coarse particles, the molding density and thus the sintering density were low, and the transverse rupture strength was 370 MPa or less.

[0062]

As described above, according to the composition for a ceramic substrate of the present invention, 2 parts by weight of glass powder are used.
Despite the fact that the ceramic powder contains 5-34% and ceramic powder 66-75%, respectively, and the proportion of ceramic is increased, the ceramic powder has at least two types of fine particles and coarse particles having different particle diameters. Consisting of particles of
The average particle size of the fine particles and the coarse particles is less than 1 μm, and the average particle size of the glass powder is less than 1 μm. Therefore, the dispersibility of the glass and the ceramic is good, and the packing property of the ceramic is enhanced, so that the glass can effectively cover the periphery of the ceramic particles in the firing step, and the density can be reduced at a firing temperature of 1000 ° C. or less. A sintered body, that is, a ceramic substrate can be obtained. In addition to the denseness of such a sintered body, an increase in the proportion of ceramic also contributes to increasing the mechanical strength of a ceramic substrate obtained by firing the composition.

Further, as described above, according to the composition for a ceramic substrate according to the present invention, a firing temperature of 1000 ° C. or less can be applied, so that a low-resistance metal such as an Ag-based or Cu-based metal is mainly used. A ceramic circuit component having a conductor circuit containing as a component can be obtained without problems by co-firing, and therefore, it is easy to obtain a ceramic circuit component having a ceramic substrate having a low dielectric constant, a high Q, and a high mechanical strength. become.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a ceramic multilayer circuit component 1 according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic multilayer circuit component 2 Ceramic board 3 Conductor circuit 4 Ceramic layer 5-7 External conductor 8-12 Internal conductor 13-19 Via hole connection part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01G 4/30 301 H01G 4/30 301E 4/40 4/40 321A (72) Inventor Osamu Yokokura Kyoto Nagaokakyo 2-26-10 Ichitenjin Murata Manufacturing Co., Ltd.F-term (reference) 4G030 AA36 AA67 BA09 BA20 CA08 GA11 GA20 HA09 PA07 PA22 4G062 AA09 AA15 BB01 DA04 DA05 DA06 DB01 DB02 DB03 DB04 DC01 DC02 DC03 DC04 DD01 DE01 DF01 EA01 EA01 EA01 EA01 EA EC01 ED01 ED02 ED03 ED04 ED05 EE01 EE02 EE03 EE04 EE05 EF01 EF02 EF03 EF04 EF05 EG01 EG02 EG03 EG04 EG05 FA01 FA10 FB01 FC01 FD01 FE01 FF01 FG01 H01 F01H01 H01 H01 H01 H01 H01 H01 H01 H01 H01 H01 H01 JJ03 JJ05 JJ07 JJ10 KK01 KK03 KK05 KK07 KK10 MM28 NN26 NN33 PP03 PP05 5E001 AB03 AC09 AC10 AD03 AE00 AE04 AF00 AH01 AH05 AH 06 AH09 AJ01 AJ02 AZ01 5E082 AB03 BB10 BC31 BC40 DD08 EE04 EE23 EE26 EE35 FF14 FG06 FG25 FG26 FG27 FG52 FG54 GG10 GG11 GG28 JJ12 JJ15 JJ23 LL15 MM22 PP03 PP09

Claims (10)

[Claims] 1. A glass powder having a weight ratio of 25 to 34.
%, And 66 to 75% of a ceramic powder, respectively, wherein the ceramic powder is composed of at least two kinds of fine particles and coarse particles having different particle diameters, and the average of the fine particles and the coarse particles combined. A composition for a ceramic substrate, wherein the composition has a particle size of less than 1 μm, and the glass powder has an average particle size of less than 1 μm. 2. The glass powder has a softening temperature of 800 ° C.
The composition for a ceramic substrate according to claim 1, wherein the composition is made of a glass having the following properties and low reactivity with a ceramic. 3. The composition for a ceramic substrate according to claim 1, wherein the ceramic powder includes an alumina powder. 4. The glass constituting the glass powder is 2
8 to 64 wt% of SiO _2, 0 to 30 wt% of B
₂ O ₃ , 0-30% by weight of Al ₂ O ₃ , and 36-5%
The composition for a ceramic substrate according to claim 3, having a composition containing 0% by weight of RO (where R is at least one selected from Mg, Ca, Sr and Ba). 5. The glass constituting the glass powder is L
i_TwoO, K_TwoO and Na_TwoAt least selected from O
The one kind of alkali metal oxide is converted to the SiO 2 _Two, B_TwoO
_Three, Al_TwoO_ThreeAnd 100 parts by weight of RO
5. The composition according to claim 4, wherein the content is not more than 5 parts by weight.
The composition for a ceramic substrate according to the above. 6. The glass constituting the glass powder is T
iO ₂ , ZrO ₂ , Cr ₂ O ₃ , CaF ₂ and CuO
At least one compound selected from the group consisting of Si
Total amount of O ₂ , B ₂ O ₃ , Al ₂ O ₃ and RO is 100
The composition for a ceramic substrate according to claim 4, wherein the composition is contained in an amount of 5 parts by weight or less based on parts by weight. 7. The ceramic powder according to claim 1, wherein the average particle diameter of the fine particles in the ceramic powder is 0.1 to 0.8 μm, and the average particle diameter of the coarse particles is 0.2 to 3.0 μm. The composition for a ceramic substrate according to any one of the above. 8. The composition for a ceramic substrate according to claim 1, wherein said ceramic powder is composed of 30 to 70% by weight of said fine particles and 70 to 30% by weight of said coarse particles. 9. A ceramic comprising: a substrate obtained by molding and firing the composition for a ceramic substrate according to claim 1; and a conductor circuit formed in relation to the substrate. Circuit components. 10. The ceramic circuit component according to claim 9, wherein the conductor circuit includes at least one metal selected from Ag, Au, and Cu as a main component.