JP2000264722A - Dielectric ceramic composition and ceramic multilayered substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a ceramic multilayered substrate excellent in electrical characteristics, temperature characteristics, etc., and capable of being sintered at a relatively low temperature. SOLUTION: Insulating ceramic layers 3a and 3b having a low dielectric constant and a dielectric ceramic layer 2 having a high dielectric constant are laminated and sintered to obtain the objective ceramic multilayered substrate 1. The insulating ceramic layers 3a and 3b comprise a glass component- containing ceramic composition sintered at a low temperature. The dielectric ceramic layer 2 comprises a dielectric composition obtained by mixing a dielectric ceramic component prepared by adding 3-17 wt.% bismuth oxide and 0.5-10 wt.% lead oxide to a principal component represented by the formula xBaO- yTiO2-zMe (where x+y+z=1 and Me is oxide of lanthanoids) with a glass component having much the same composition as the above glass component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dielectric ceramic composition having a high dielectric constant, and a ceramic obtained by laminating and sintering a dielectric ceramic layer having a low dielectric constant and a dielectric ceramic layer having a high dielectric constant. The present invention relates to a multilayer substrate.

[0002]

2. Description of the Related Art In recent years, the performance of electronic components has been remarkably improved in the field of electronics. In particular, in information processing apparatuses such as large computers, mobile communication terminals, and personal computers that support the information society, the information processing speed has been increased. In addition, miniaturization and multifunctionalization of devices have been promoted. The performance improvement of such an information processing device is mainly
It is realized by high integration, high speed, and high functionality of semiconductor devices such as VLSI and ULSI. However, even if the speed of the semiconductor device is increased and the performance thereof is improved, the operation as a system is limited by noise due to signal delay, crosstalk, impedance mismatch, power supply fluctuation, and the like on a substrate connecting the devices. There was something.

For this reason, so-called multi-chip modules (MCMs), in which a plurality of high-performance semiconductor devices are mounted on a ceramic substrate, have been put to practical use as electronic components for performing high-speed and high-performance information processing. In such a module, a ceramic multilayer substrate in which line conductors are three-dimensionally arranged is useful for increasing the packaging density of LSIs and the like and electrically connecting the LSIs satisfactorily.
Alumina has been used as a material for the ceramic multilayer substrate.

However, since alumina alone has a high sintering temperature of 1300 ° C. or higher, it is necessary to use a refractory metal such as tungsten or molybdenum as a line conductor for the inner layer, and to prevent oxidation of the refractory metal. From this point, it was necessary to perform sintering in a reducing atmosphere. Also,
These refractory metals have a problem that high density wiring is difficult because of high specific resistance. Furthermore, alumina has a large dielectric constant of about 10, which causes a large signal delay when the mounted semiconductor device is operated at a high speed and a large thermal expansion coefficient as compared with silicon. In some cases, the reliability may be reduced.

Therefore, in order to solve these problems,
Research on a low-temperature sintered ceramic composition, which is a composite material of a ceramic composition and a glass component, is being actively conducted, and practical application as a substrate for a multilayer module or a multilayer device is in progress. Low-temperature sintered ceramic composition is a composition obtained by adding a glass component to a ceramic component serving as a base material,
By lowering the sintering temperature, the degree of freedom in designing the material properties and sintering temperature can be greatly expanded. In particular, a low-temperature sintered ceramic composition can be simultaneously sintered as a low-melting metal such as silver or copper having a low specific resistance as an electrode material.
A ceramic multilayer substrate excellent in high frequency characteristics can be formed.

[0006]

In recent years, a passive element such as a capacitor or an inductor, which has been a component of a surface mounted device (SMD), has been incorporated into a ceramic multilayer substrate to further increase the module. Attempts have been made to reduce the overall size.
When these elements are embedded in a ceramic multilayer substrate,
If the characteristics of the built-in element are deteriorated compared to the characteristics of the mounted components mounted on the board surface, the merit of incorporating the element is reduced by half, so the built-in element is equivalent to the element mounted on the board Or higher.

For this reason, it is usual to select a material for the constituent layers of the ceramic multilayer substrate so as to sufficiently exhibit the electrical characteristics of each of the elements contained therein. A ceramic multilayer substrate has been developed in which a dielectric ceramic material having a high dielectric constant is selected and an insulating ceramic material having a low dielectric constant (particularly, a low-temperature sintered ceramic composition) is selected for other layers.

Here, as a material used for the low dielectric constant insulating ceramic layer, factors deteriorating electrical characteristics such as stray capacitance generated between elements such as built-in capacitors and inductors and coupling capacitance between wirings are used. Since it is necessary to keep it low, and when used in high frequency applications, the relative dielectric constant εr
It is generally advantageous to use a material satisfying εr ≦ 10 because the lower the

On the other hand, as a material used for a dielectric ceramic layer having a high dielectric constant, the present applicant discloses in Japanese Patent Publication No. 5-68044 that xBaO-yTiO ₂ -zMe (however,
x + y + z = 1, Me is an oxide of a lanthanoid element. ), Where x, y and z are a,
The main components in the molar ratio range surrounded by b, c and d include:
Bismuth oxide 3 to 17% by weight, lead oxide 0.5 to 10
We propose a dielectric ceramic material which is added by weight% respectively.

[0010]

[Table 1]

This dielectric ceramic material has a high dielectric constant, a linear rate of change in resonance frequency with temperature, and a wide temperature-compensable range. It is a ceramic material.

However, since the dielectric ceramic material itself has a high sintering temperature, it is difficult to simultaneously sinter it with a low melting point metal such as copper or silver having a small specific resistance. (Resin ceramic substrate), the strength of the resulting ceramic multilayer substrate may be reduced when a ceramic multilayer substrate is manufactured using this. Further, inter-diffusion of components may occur between a dielectric ceramic layer having a high dielectric constant and an insulating ceramic layer having a low dielectric constant, which may cause fluctuations in substrate characteristics.

Further, when a glass component is added to the above-mentioned dielectric ceramic material for the purpose of lowering the sintering temperature, the substrate strength is significantly lower than that of an alumina substrate or the like depending on the type and content of the glass component. Also, even if the substrate strength is high, the substrate characteristics such as the electrical characteristics and the temperature characteristics may be reduced. In particular, when emphasis is placed on the strength of the substrate, its relative dielectric constant is reduced, making it difficult to incorporate a capacitor having a large capacity in the substrate. Even if it can be incorporated, the electrode area occupied by the capacitor increases. This is disadvantageous for downsizing of the substrate and high-density mounting. On the other hand, when importance is placed on the electrical characteristics and the temperature characteristics, the strength of the substrate is reduced, and it may be unsuitable as a mounting substrate on which electronic components such as semiconductor ICs are mounted.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a dielectric ceramic composition which is excellent in electric characteristics and temperature characteristics and can be sintered at a relatively low temperature.
Another object of the present invention is to provide a ceramic multilayer substrate having high substrate strength, excellent substrate characteristics such as electric characteristics and temperature characteristics, and sinterable at a relatively low temperature.

[0015]

That is, the present invention provides xBa.
O-yTiO ₂ -zMe (where x + y + z = 1, Me
Is an oxide of a lanthanoid element. ),
Bismuth oxide is used as a main component in which x, y and z are within a range of a molar ratio surrounded by a, b, c and d shown in Table 1 below.
A dielectric ceramic component obtained by adding 7% by weight and 0.5-10% by weight of lead oxide to a glass component comprising barium oxide, silicon oxide and boron oxide. It relates to a ceramic composition.

[0016]

[Table 1]

[0017] In the dielectric ceramic composition of the present invention, the glass component may include barium oxide of 15.0 to 15.0.
65.0 mol%, 5.0 to 55.0 mol% of silicon oxide, and 10.0 to 75.0 mol% of boron oxide are mixed, respectively.

Further, the dielectric ceramic composition of the present invention is characterized in that the content of the glass component is 5.0 to 35.0% by weight based on the dielectric ceramic component.

Further, the dielectric ceramic composition of the present invention is characterized in that the oxide of the lanthanoid element is NdO _3/2 .

Further, the present invention provides a ceramic multilayer substrate obtained by laminating and sintering an insulating ceramic layer having a low dielectric constant and a dielectric ceramic layer having a high dielectric constant, wherein the insulating ceramic layer contains a glass component. Wherein the dielectric ceramic layer comprises xBaO-y.
TiO ₂ -zMe (where x + y + z = 1, Me is an oxide of a lanthanoid element), and x, y and z are molar ratios surrounded by a, b, c and d shown in Table 1 above. A glass component having substantially the same composition as the above glass component is mixed with a dielectric ceramic component obtained by adding bismuth oxide at 3 to 17% by weight and lead oxide at 0.5 to 10% by weight to the main components in the range of A ceramic multilayer substrate characterized by comprising a dielectric ceramic composition comprising:

Further, in the ceramic multilayer substrate of the present invention, the glass component in the dielectric ceramic composition is 15.0 to 65.0 mol% of barium oxide and 5.0 to 55.0 mol% of silicon oxide. 10. Boron oxide.
0 to 75.0 mol%, each being mixed.

Further, in the ceramic multi-layer substrate of the present invention, the content of the glass component in the dielectric ceramic composition may be adjusted to 5.0 to 3 with respect to the dielectric ceramic component.
It is characterized by being 5.0% by weight.

The ceramic multilayer substrate according to the present invention is characterized in that the oxide of the lanthanoid element is NdO _3/2 .

Further, in the ceramic multilayer substrate of the present invention, the low-temperature sintered ceramic composition may be made of BaO-Al2O3-S
It is characterized by being made of an iO2-based glass composite material.

According to the dielectric ceramic composition of the present invention, xBaO-yTiO ₂ -zMe (where x + y + z
= 1, Me is an oxide of a lanthanoid element such as NdO _3/2 . ), And x, y and z are as shown in Table 1 above.
The main components in the molar ratio range enclosed by a, b, c and d shown in FIG.
5-10% by weight of the dielectric ceramic component is added to the glass component consisting of barium oxide, silicon oxide and boron oxide, so that the dielectric ceramic component retains excellent electrical and temperature characteristics. In addition, a dielectric ceramic composition having a low sintering temperature and a high strength after sintering can be obtained.

According to the ceramic multilayer substrate of the present invention, the dielectric ceramic layer is made of xBaO-yTiO ₂
-ZMe (where x + y + z = 1, Me is an oxide of a lanthanoid element), and x, y, and z are ranges of a molar ratio surrounded by a, b, c, and d shown in Table 1 below. A dielectric ceramic component obtained by adding 3 to 17% by weight of bismuth oxide and 0.5 to 10% by weight of lead oxide to a main component in the above, and a glass component having substantially the same composition as the above glass component are mixed. Since it is composed of a dielectric ceramic composition, the bonding property between the insulating ceramic layer and the dielectric ceramic layer is good, and a high dielectric constant and excellent temperature characteristics of the dielectric ceramic layer are maintained. A ceramic multilayer substrate which can be sintered at a relatively low temperature, has high strength after sintering, and has excellent high frequency characteristics and stability.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments.

First Embodiment As shown in FIG. 1, a ceramic multilayer substrate 1 according to the present embodiment has a thick film resistor 6 and a mounting component 7 such as a semiconductor IC or a chip capacitor mounted on one main surface. Te becomes, the dielectric ceramic composition of the present invention the dielectric ceramic layers 2 formed by sintering during the _{BaO-Al 2 O 3 -SiO 2} (BAS) made of a material such as an insulating ceramic layer 3a and 3b Is provided.

Then, on the dielectric ceramic layer 2, a capacitor composed of the electrodes 4a, 4b and 4c is formed. The electrodes 4a and 4c are connected via via holes 5b, and predetermined capacitances are formed between the electrodes 4a and 4b and between the electrodes 4b and 4c, respectively. It is the capacity of the entire capacitor. This capacitor is connected to the thick film resistor 6 via the via holes 5a and 5c.

Similarly, on the dielectric ceramic layer 2, a capacitor composed of the electrodes 4d, 4e and 4f is formed. The electrode 4d and the electrode 4f are connected via a via hole 5f, and a predetermined capacitance is formed between the electrode 4d and the electrode 4e and between the electrode 4e and the electrode 4f, respectively. Is the capacity of the whole. This capacitor is connected to the mounted component 7 via the via holes 5d and 5e.

As described above, in the ceramic multilayer substrate 1, since the capacitor is formed in the ceramic multilayer substrate 1, the size of the substrate is reduced, and a high dielectric constant is provided between the electrodes forming the capacitor. Since the dielectric ceramic layer 2 is interposed, a capacitor having a large capacitance can be formed with a relatively small electrode pattern.

Further, since the constituent material of the dielectric ceramic layer 2 contains a glass component having substantially the same composition as the glass component in the insulating ceramic layers 3a and 3b, the insulating ceramic layers 3a and 3b and the dielectric ceramic layer 2, and the fluctuation of the substrate characteristics due to the mutual diffusion of the components can be suppressed. Furthermore, the high dielectric constant and excellent temperature characteristics of the dielectric ceramic material are maintained, and the ceramic multilayer substrate 1 having both high substrate strength and excellent substrate characteristics is formed.

Second Embodiment Next, a second embodiment according to the present invention will be described with reference to FIG.

The ceramic multilayer substrate 11 has mounted thereon mounting components 7 such as chip resistors and semiconductor ICs on one main surface, and a dielectric ceramic layer 12a and a dielectric ceramic layer 12a formed by sintering the dielectric ceramic composition of the present invention. 12b are provided between the electrodes 14a and 14b and between the electrodes 14c and 14d provided in the insulating ceramic layer 13 made of, for example, a BAS material or the like by a thick film printing method or the like. I have.

Then, the electrodes 14a, 14b, and
Dielectric ceramic layer 12a provided between these electrodes
A predetermined capacitance is formed by the
A predetermined capacitance is formed by 4c, the electrode 14d, and the dielectric ceramic layer 12b. And the electrode 14
The capacitor formed by a and the electrode 14b is connected to the mounting component 7 via the via hole 15a on the one hand, and is connected to the strip line 18 via the via hole 15b on the other hand. The capacitor formed by the electrode 14c and the electrode 14d is connected to the mounting component 7 via the via hole 15c and the line conductor 16 on the one hand, and is connected to the ground conductor 17 via the via hole 15d on the other hand. I have.

As described above, in the ceramic multilayer substrate 11, since the capacitor is formed in the ceramic multilayer substrate, the size of the substrate can be reduced, and a dielectric having a high dielectric constant can be provided between the electrodes forming the capacitor. Since the body ceramic layers 12a and 12b are sandwiched, a capacitor having a large capacitance is formed with a relatively small electrode pattern.

Further, the dielectric ceramic layers 12a and 1a
Since the constituent material 2b is the dielectric ceramic composition of the present invention containing a glass component having substantially the same composition as the glass component in the insulating ceramic layer 13, the insulating ceramic layer 13 and the dielectric ceramic layers 12a and 12b Has a high adhesive strength, and fluctuations in substrate characteristics due to interdiffusion of constituent components are suppressed. Further, the excellent electrical characteristics and temperature coefficient of the dielectric ceramic material are maintained, and the ceramic multilayer substrate 11 having both high substrate strength and excellent substrate characteristics can be obtained.

Next, an example of a method for manufacturing a ceramic multilayer substrate according to the first embodiment of the present invention will be described.

First, as a material for the insulating ceramic layer, a ceramic raw material powder containing alumina as a main component;
aO-, after preparing a glass component SiO ₂ as a main raw material, the glass component with respect to 100 parts by weight of alumina 20-3
0 parts by weight are added and mixed. If necessary, the main raw material before mixing may be calcined at about 800 to 1100 ° C.

The material for the insulating ceramic layer is, for example, Mg ₂ SiO ₄ , CaZrO ₃ , BaAl ₂ Si ₂ O ₈
For example, a material obtained by adding a glass component such as BaO or SiO ₂ or a material containing BaO, Al ₂ O ₃ , or SiO ₂ as a main component may be used. For _{example, B 2 O 3 -BaO-Al} 2 O 3 -S
When using the ceramic raw material powder for the iO ₂ as a main component, after mixing them, calcined at 800 to 1000 ° C..

Next, to the obtained ceramic raw material powder,
An organic slurry is prepared by adding an appropriate amount of a binder, a dispersant, a plasticizer, an organic solvent and the like and mixing them. This, if formed into a sheet by a doctor blade method or the like, a green sheet is obtained insulating ceramic layer made of BaO-Al ₂ O ₃ -SiO ₂ based glass composite material.

Next, separately from this, xBaO-yTiO ₂ -z is used as a material for the dielectric ceramic layer having a high dielectric constant.
Me (where x + y + z = 1, Me is an oxide of a lanthanoid element such as NdO _3/2 ), and x,
The main component having y and z in the molar ratio range surrounded by a, b, c, and d shown in Table 1 is bismuth oxide (Bi).
₂ O ₃ ) in an amount of 3 to 17% by weight, and lead oxide (PbO) in an amount of 0.5 to
A ceramic powder mixed with 10% by weight is prepared and calcined at 1000 ° C. for 1 hour or more in a reducing atmosphere.

Subsequently, after the obtained calcined raw material was pulverized, 15.0 to 65.0 mol% of barium oxide, 5.0 to 55.0 mol% of silicon oxide, and 10.0 mol% of boron oxide were used.
After mixing with 5.0 to 35.0% by weight of each of the glass components to be mixed, an appropriate amount of an organic vehicle, a dispersant, a plasticizer, an organic solvent, and the like are added, and these are mixed. To prepare an organic slurry. If this is formed into a sheet by a doctor blade method or the like, a green sheet for a dielectric ceramic layer can be obtained.

The thus obtained green sheets for the insulating ceramic layer and the green sheets for the dielectric ceramic layer were formed with holes for via holes as necessary, and filled with electrode paste or electrode powder to form via holes. Thereafter, an electrode paste is printed so that a capacitor having a predetermined pattern is formed on each green sheet, and the green sheet for the dielectric ceramic layer and the green sheet for the insulating ceramic layer are stacked.

Thereafter, the stacked green sheets are pressed to form blocks. If necessary, the produced block may be cut into an appropriate size or a groove may be formed. Then, the obtained block is sintered at 1000 ° C. or lower to obtain a ceramic multilayer substrate having a built-in capacitor as shown in FIG.

As described above, the material for the dielectric ceramic layer may be formed into a green sheet and embedded in a ceramic multilayer substrate, but the raw material powder for the dielectric ceramic layer may be formed in an organic vehicle. The mixture may be mixed with an organic solvent, a plasticizer, or the like to form a paste, and a dielectric ceramic layer may be formed by printing the obtained dielectric paste on a necessary portion in a thick film (see FIG. 2). Also in this case, after the formation of the dielectric ceramic layers, the green sheets are stacked, and a ceramic multilayer substrate can be manufactured through processes such as pressing, cutting, and sintering.

Next, the ceramic multilayer substrate of the present invention will be described in more detail. In the ceramic multilayer substrate of the present invention, a glass component obtained by mixing barium oxide, silicon oxide and boron oxide is used as the glass component. Accordingly, a ceramic multilayer substrate which can be sintered at a low temperature while maintaining the characteristics of the dielectric ceramic component well, has high substrate characteristics, and is excellent in substrate characteristics such as electric characteristics and temperature characteristics can be obtained.

The glass component obtained by mixing barium oxide, silicon oxide and boron oxide is, for example, BaO
-Al ₂ O _3- SiO _{2 and} other low-temperature sintered ceramic materials have almost the same composition as glass components, so that an insulating ceramic substrate made of an insulating ceramic material and a dielectric ceramic layer made of a dielectric ceramic material And a ceramic multilayer substrate having high substrate strength can be obtained.

Particularly, in the ceramic multilayer substrate of the present invention and the dielectric ceramic composition of the present invention, 15.0 to 65.0 mol% of barium oxide (BaO) and 5.0 to 55% of silicon oxide (SiO ₂ ) are used. If a glass component obtained by mixing 10.0 to 75.0 mol% of boron oxide (B ₂ O ₃ ) with the dielectric ceramic composition is used in the dielectric ceramic composition, for example, the relative dielectric constant εr is 40 or more, Excellent electric characteristics with a Q value of 1500 or more can be achieved, and also excellent temperature characteristics such as having a stable resonance frequency temperature coefficient τf can be achieved.

When the content of the glass component is within the range of 5.0 to 35.0% by weight with respect to the dielectric ceramic material, the electrical characteristics such as the relative dielectric constant εr and the Q value and the resonance frequency The balance with temperature characteristics such as the temperature coefficient τf is excellent. The content of the glass component was 5.0% by weight.
If it is less than 3, the sintering temperature tends to be high,
When the content of the glass component exceeds 35.0% by weight, the substrate strength (flexural strength) tends to decrease.

Further, BaO-A is formed on the insulating ceramic layer.
Using the l ₂ O ₃ -SiO ₂ based low-temperature co-fired ceramic material made of a glass composite material, small silver resistivity in the ceramic multilayer substrate, a silver - palladium, copper, low-melting-point metal such as gold (or alloy) Can be disposed as an electrode material and can be simultaneously sintered, so that a ceramic multilayer substrate excellent in high-frequency characteristics can be formed. In particular, since the low-temperature sintered ceramic material has substantially the same composition as the glass component obtained by mixing barium oxide, silicon oxide and boron oxide, the compatibility is good, and therefore, the adhesive strength with the dielectric ceramic layer described above. And variations in substrate characteristics are small.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to these embodiments.

For example, the material of the low-temperature sintered ceramic substrate is not limited to the BAS material.
It is also possible to use _{-SrO-SiO 2, BaO-SiO} 2 -Li 2 O low-temperature co-fired ceramic material, such as. These low-temperature sintering ceramic materials are made of BaO, Si
It is a material containing a glass component having substantially the same composition as the glass component composed of O ₂ and B ₂ O ₃ .

The ceramic multilayer substrate of the present invention is used not only as a ceramic substrate on which electronic components such as semiconductor ICs are mounted, but also as a material for electronic components such as a dielectric resonator for microwaves and an LC filter. Can be used as a ceramic package or the like. Further, by forming a resistor on or on the back surface of the ceramic multilayer substrate, or by forming a choke coil or a strip line in the insulating ceramic substrate or the dielectric ceramic layer, the size of the substrate can be further reduced. Can be achieved.

[0055]

The present invention will be described below with reference to specific examples.

First, BaO, TiO ₂ , NdO _3/2 , Bi
₂ O ₃ and PbO were mixed in predetermined amounts shown in Table 2 and calcined in air at 1000 ° C. or higher for 1 hour or longer. Subsequently, after the calcined ceramic raw material powder was pulverized, a predetermined amount of a glass component composed of BaO, SiO ₂ and B ₂ O ₃ mixed at a ratio shown in Table 2 below was added, and a binder, a dispersant, and a plasticizer were further added. Then, an appropriate amount of an organic solvent was added and mixed to prepare an organic slurry for a dielectric ceramic layer.

[0057]

[Table 2]

Next, this was formed into a sheet shape based on the doctor blade method to produce a green sheet for a dielectric ceramic layer, and then the green sheets were stacked by a required thickness and pressed. It was cut into an appropriate shape. Then, this is placed in a reducing atmosphere at 1000
Sintered below ℃. Then, electrodes are provided on both sides of the obtained sheet-shaped dielectric ceramic, and the relative permittivity εr, Q
And the temperature coefficient τf of the resonance frequency at −25 ° C. to + 85 ° C. were measured. The measurement results are shown in Table 3 below.

A green sheet prepared by molding a low-temperature sintered ceramic material made of a BAS material into a sheet and the above-described green sheet for a dielectric ceramic are stacked to form a ceramic multilayer substrate as shown in FIG. It was fabricated and its substrate strength and sintering temperature were measured. The measurement results of the substrate strength and the sintering temperature are also shown in Table 3 below. In addition,
The sintering temperature in Table 3 indicates the temperature at which the density becomes highest.

[0060]

[Table 3]

As shown in Tables 2 and 3, Examples 1 to 7
As shown in the three-component diagram of FIG. 3, the composition ratio of the glass component consisting of BaO, SiO ₂ and B ₂ O ₃
O is 15.0 to 65.0 mol%, SiO ₂ is 5.0 to 5
When 5.0 mol% and B ₂ O ₃ are 10.0 to 75.0 mol%, the substrate has a high relative dielectric constant εr, and shows excellent values of Q value and τf. It can be seen that there are advantages such as high strength (flexural strength) and low sintering temperature.

Further, regarding Examples 1, 14 to 16, when the balance between substrate strength and sintering temperature is considered, the content of the glass component with respect to the dielectric ceramic component is 5.0 to 3
It turns out that 5.0 weight% is desirable.

In particular, from Examples 1 to 7 and Example 15, Ba
The composition ratio of the glass component consisting of O, SiO ₂ and B ₂ O ₃ is 15.0 to 65.0 mol% for BaO, 5.0 to 55.0 mol% for SiO ₂ , and 10 for B ₂ O ₃ . 0-75.0
Mol%, and when the content of the glass component with respect to the dielectric ceramic component is 5.0 to 35.0% by weight,
Excellent electrical characteristics with relative permittivity εr of 40 or more and Q value of 1700 or more, and temperature coefficient τf of resonance frequency of ± 60
It can be seen that excellent temperature characteristics within ppm / ° C. are shown. Further, since the sintering temperature is as low as 1000 ° C. or less, it can be seen that they can be sintered simultaneously with the insulating ceramic substrate made of BAS and the low melting point metal, and have excellent substrate strength.

On the other hand, as can be seen from Example 8, when the composition ratio of BaO in the glass component is 15.0 mol% or less, the sintering temperature becomes too high and the Q value tends to decrease. is there. Further, as can be seen from Example 9, when the composition ratio of BaO in the glass component exceeds 65.0 mol%, the temperature characteristics tend to deteriorate.

Further, as can be seen from Example 10, when the composition ratio of SiO _{2 in} the glass component is less than 5.0 mol%, the flexural strength is reduced, and it becomes difficult to use it as a substrate. On the other hand, as can be seen from Example 11, when the composition ratio of SiO ₂ exceeds 55.0 mol%, the sintering temperature becomes too high, and the sintering temperature of Cu is reached, so that the electrode made of Cu may be damaged. There is.

As can be seen from Example 12, when the composition ratio of B ₂ O ₃ in the glass component is less than 10.0 mol%, the sintering temperature becomes too high, and the ceramic is sintered at a temperature higher than the sintering temperature of Cu. Because of the necessity of connection, the Cu electrode is damaged. On the other hand, as can be seen from Example 13, B
_When the composition ratio of ₂ O ₃ exceeds 75.0 mol%, the sintering temperature becomes too low, and co-fired Cu may not be sintered.

Further, with respect to the addition amount of the glass component to the dielectric ceramic component, as shown in Example 14, if the amount is less than 5.0% by weight, the sintering temperature rises.
It has been found that when the content exceeds 5.0% by weight, the substrate strength tends to decrease.

As described above, according to the present embodiment, a ceramic composition having a low dielectric constant is used for a portion which is considered to be disadvantageous in terms of characteristics when stray capacitance is generated, and a dielectric material having a high dielectric constant is used for a portion requiring a large capacitance. By using the ceramic composition, a large-capacity capacitor can be built in, and the ceramic multilayer substrate is significantly reduced in size and height.

At the same time, since a ceramic composition having a high dielectric constant is incorporated only in necessary portions, stray capacitance between electrodes and wirings can be minimized. When the dielectric ceramic layer portion having a high dielectric constant is incorporated as a green sheet or the like, for example, since the dielectric film thickness between the capacitors can be made constant, a very high-precision large-capacity capacitor can be used. It can be formed without necessarily performing trimming.

Furthermore, since the low dielectric constant insulating ceramic layer and the high dielectric constant dielectric ceramic layer contain glass components having substantially the same composition, their joining works properly, and the insulating ceramic layer and the dielectric ceramic layer have a high dielectric constant. The bonding strength with the body ceramic layer is very large, and the strength of the substrate is greatly improved.

[0071]

The dielectric ceramic composition according to the present invention has x
BaO-yTiO ₂ -zMe (where x + y + z = 1,
Me is an oxide of a lanthanoid element. ), And x, y and z are bismuth oxide as a main component having a molar ratio in a range of a, b, c and d shown in Table 1 below.
The electrical characteristics such as the relative dielectric constant ε and the Q value of the dielectric ceramic component obtained by adding 0.5 to 10% by weight of lead oxide and the temperature characteristics such as the temperature coefficient τf of the resonance frequency. The dielectric ceramic composition has excellent balance, can be sintered at a relatively low temperature, and has high strength after sintering.

In the ceramic multilayer substrate of the present invention, the insulating ceramic layer and the dielectric ceramic layer are satisfactorily joined together, the electrical characteristics of the dielectric ceramic layer, such as the relative permittivity ε and the Q value, and the temperature of the resonance frequency. It is excellent in balance with temperature characteristics such as coefficient τf, and has high strength after sintering and can be sintered at low temperature, so that a ceramic multilayer substrate excellent in stability and high frequency characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a ceramic multilayer substrate according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of a ceramic multilayer substrate according to a second embodiment of the present invention.

FIG. 3 is a three-component diagram showing a composition range of a glass component in the dielectric ceramic composition of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ceramic multilayer substrate, 2 ... Dielectric ceramic layer, 3a, 3b ... Insulating ceramic layer, 4a, 4b, 4c, 4d, 4e, 4f ... Electrode, 5a, 5b, 5c, 5d, 5e, 5f ... Via hole, 6,7 ... Surface mount components

Continued on the front page F-term (reference) 4G031 AA06 AA07 AA11 AA28 AA30 AA32 AA35 BA09 5G303 AA05 AB06 AB08 AB11 AB12 AB15 BA06 BA12 CA03 CB02 CB03 CB05 CB22 CB25 CB30 CB35

Claims (9)

[Claims] (1) xBaO-yTiO ₂ -zMe (provided that
x + y + z = 1, Me is an oxide of a lanthanoid element. ), Where x, y and z are a,
Barium oxide is added to a dielectric ceramic component obtained by adding bismuth oxide at 3 to 17% by weight and lead oxide at 0.5 to 10% by weight to a main component in a molar ratio range surrounded by b, c and d, respectively. A dielectric ceramic composition comprising a mixture of glass components consisting of silicon oxide and boron oxide. [Table 1] 2. The glass component according to claim 1, wherein the glass component is barium oxide.
5.0-65.0 mol%, silicon oxide is 5.0-55.
The dielectric ceramic composition according to claim 1, wherein 0 mol% and boron oxide are mixed at 10.0 to 75.0 mol%, respectively. 3. The dielectric ceramic composition according to claim 1, wherein the content of the glass component is 5.0 to 35.0% by weight based on the dielectric ceramic component. object. 4. The method according to claim 1, wherein the oxide of the lanthanoid element is Nd.
The dielectric ceramic composition according to claim 1, wherein the composition is O3 _{/ 2} . 5. A ceramic multilayer substrate obtained by laminating and sintering an insulating ceramic layer having a low dielectric constant and a dielectric ceramic layer having a high dielectric constant, wherein the insulating ceramic layer is sintered at a low temperature containing a glass component. a ceramic composition, said dielectric ceramic layer, xBaO-yTiO ₂ -z
Me (where x + y + z = 1, Me is an oxide of a lanthanoid element), and x, y and z are as shown in the following table.
A dielectric ceramic component obtained by adding bismuth oxide in an amount of 3 to 17% by weight and lead oxide in an amount of 0.5 to 10% by weight to a main component in a molar ratio range surrounded by a, b, c and d shown in FIG. And a dielectric ceramic composition obtained by mixing a glass component having substantially the same composition as the glass component. [Table 1] 6. The glass component in the dielectric ceramic composition comprises 15.0 to 65.0 mol% of barium oxide, 5.0 to 55.0 mol% of silicon oxide, and 10.0 to 5 mol% of boron oxide. The ceramic multilayer substrate according to claim 5, wherein 75.0 mol% of each is mixed. 7. The dielectric ceramic composition according to claim 5, wherein the content of the glass component is 5.0 to 35.0% by weight with respect to the dielectric ceramic component. 4. The ceramic multilayer substrate according to claim 1. 8. The method according to claim 1, wherein the oxide of the lanthanoid element is
The ceramic multilayer substrate according to claim 5, wherein the substrate is dO3 _{/ 2} . 9. The method according to claim 1, wherein the low-temperature sintered ceramic composition is BaO.
The ceramic multilayer substrate according to claim 5, wherein the ceramic multilayer substrate is an Al2O3-SiO2-based glass composite material.