JPH10200267A - Glass composition for substrate having built-in lead dielectric and multilayer substrate having built-in capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass composition for a substrate having a built-in lead- based dielectric capable of inhibiting deterioration of the dielectric constant of a dielectric layer at the time of baking and a multilayer substrate having a built-in capacitor using the multilayer substrate having the built-in capacity employing the gals composition and further a dielectric material having the high degree of sinterability in the multilayer substrate, into which a capacitor section with the dielectric layer containing a lead-based perovskite compound is incorporated. SOLUTION: The deterioration of the dielectric constant of a dielectric 31 is suppressed by using substrate materials 21-24 containing the glass composition for the substrata having the built-in lead-based dielectric consisting of 10-35mol% Al2 O3 , 20-60mol% CaO and 8-40mol% SiO2 . The above-mentioned glass composition may also contain at most 30mol% oxide of at least one kind selected from MgO, BaO and SrO, and may also comprise not more than 10mol% TiO2 . The dielectric constant of the simultaneously sintered dielectric can further be increased by adding a lead silicate compound to a lead perovskite compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multilayer substrate having a capacitor section.

[0002]

2. Description of the Related Art In order to increase the density of wiring on a circuit board, it has been proposed to incorporate a capacitor in a multilayer board {Electro Ceramics vol. 18, No. 5, 1987}. When manufacturing such a multilayer substrate, it is necessary to simultaneously fire the conductor material, the dielectric material, and the substrate material. The firing temperature at this time is usually lower than the melting point of the conductor material,
When Ag or Ag-Pd, which has good characteristics and is inexpensive but has a low melting point, is used as the conductor material, it is necessary to use a glass-ceramic composite substrate material having a low firing temperature. The glass-ceramic composite substrate contains a glass powder in addition to an aggregate such as Al ₂ O _{3. In} order to lower the softening point and improve the wettability to the aggregate, for example, As described in JP-A-2-230606, those having a total content of SiO ₂ and B ₂ O _{3 of} about 30% by weight or more are used. On the other hand, it is necessary to use a dielectric material having a high dielectric constant in order to obtain a small-sized and high-capacity capacitor. It is expected because it is possible (Circuit Technology, 6 [1], 28 (1991), 1st Microelectronics Symposium (May 1985, Tokyo), p73, IEMT Symposium (1993 Kanazawa, 1993), p70).

When a lead-based perovskite compound is used as a thick film device (functional film having a thickness of about 10 to 30 μm) such as a capacitor, it is necessary to add a binder such as glass and a sintering aid. Become.

[0004]

However, SiO ₂ or B ₂ O ₃ in a glass-ceramic composite substrate, or SiO ₂ previously added to a dielectric material as a sintering aid.
Caused by reaction with _second magnitude (Journal of the Ceramic Society of Japan 94 [9], 936 (1986))
Then, the perovskite phase is decomposed into a pyrochlore phase, and the dielectric constant of the built-in dielectric is reduced to about 1700 to 2000. Therefore, it is not possible to obtain a desired capacitance, and if the capacitance is designed in advance in consideration of a decrease in the capacitance, the effective area of the dielectric must be increased, which hinders downsizing of the substrate, which is a problem. .

Accordingly, the present invention provides a lead-based dielectric material having a dielectric layer containing a lead-based perovskite compound and capable of suppressing deterioration of the dielectric constant of the dielectric layer during firing. An object of the present invention is to provide a glass composition for a body-containing substrate, a multilayer substrate with a built-in capacitor using the glass composition, and a multilayer substrate with a built-in capacitor using a dielectric material having high sinterability.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on a glass composition for a substrate containing a lead-based dielectric, and as a result, the glass composition contained in the substrate has been diffused during firing and has been deposited in the dielectric layer. In view of the fact that the lead-based perovskite compound is decomposed to form a pyrochlore compound having a low dielectric constant, it is found that the lead-based perovskite compound does not decompose if the following novel glass composition is used as a substrate material. The present invention has been accomplished based on this finding.

[0007] Such an object is achieved by the constitutions (1) to (10).

(1) 10 to 35 mol% of Al ₂ O ₃ , CaO
A glass composition for a substrate containing a lead-based dielectric, comprising 20 to 60 mol% and _{8 to} 40 mol% of SiO2.

(2) The glass composition for a substrate containing a lead-based dielectric according to (1), wherein the glass composition contains at least one oxide selected from MgO, BaO and SrO in an amount of 30 mol% or less.

(3) The glass composition for a substrate containing a lead-based dielectric according to (2), which contains 10 mol% or less of TiO ₂ .

(4) 60 to 90% by volume of the glass composition for a substrate containing a lead-based dielectric according to any one of (1) to (3).
A glass-ceramic composite substrate composition to be contained.

(5) A multilayer substrate with a built-in capacitor, wherein the substrate composition described in (4) and the lead-based dielectric composition are co-fired.

(6) The multilayer substrate with a built-in capacitor according to (5), wherein the lead-based dielectric composition contains at least a lead-based perovskite compound and a lead silicate compound.

(7) The composition of the lead silicate compound is S
iO ₂ 18-43 mol%, PbO 55-80 mol%, A
The multilayer substrate with a built-in capacitor according to (6), wherein l ₂ O _{3 is} 1 to 5 mol% and the content is 3 to 20% by weight.

(8) The composition of the lead silicate compound is S
iO ₂ 10~40 mol%, PbO50~75 mol%, A
l ₂ O ₃ 1 to 15 mol%, CuO 1 to 20 mol%,
The multilayer substrate with a built-in capacitor according to (6), wherein the content is 3 to 20% by weight.

(9) The composition of the lead silicate compound is S
iO ₂ 10~40 mol%, PbO50~75 mol%, A
l ₂ O ₃ 1 to 15 mol%, _1/2 20 mol% CuO + AgO, its content is 3 to 20 wt% (6)
2. The multilayer substrate with a built-in capacitor according to item 1.

(10) A multilayer substrate having a built-in capacitor portion having a dielectric layer and an electrode layer between a pair of glass-ceramic composite substrates, and having a buffer layer between the capacitor portion and each glass-ceramic composite substrate. A multilayer substrate with a built-in capacitor, wherein the dielectric layer contains a lead-based perovskite compound, and a substrate made of the glass-ceramic composite substrate composition of (4) is used as a buffer layer.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a specific configuration of the present invention will be described in detail.

FIG. 1 is a sectional view of a multilayer substrate with a built-in capacitor according to the present invention. In the figure, the dielectric layer 31 is the electrode 4
1 and 42, a capacitor portion is formed, and the capacitor portion is composed of glass-ceramic composite substrates 21, 22, 2
It is sandwiched between 3, 24. End electrodes 51, 5 are provided on the outer surfaces of the glass-ceramic composite substrates 21 to 24, respectively.
2 are provided, and these end electrodes are connected to the internal electrodes 41 and 42, respectively.

The multilayer substrate according to the present invention is usually manufactured by a printing method or a sheet method. In the printing method, a conductor paste and a dielectric paste are alternately printed on a green sheet of a glass-ceramic composite substrate containing a glass composition that does not decompose a lead-based perovskite compound so as to have a predetermined number of layers. A green sheet of a glass-ceramic composite substrate containing a glass composition that does not decompose the perovskite compound is overlaid and fired. On the other hand, in the sheet method, a conductive paste was printed on a dielectric green sheet, and a conductive paste was printed on a green sheet of a glass-ceramic composite substrate containing a glass composition that did not decompose the lead-based perovskite compound, and the conductive paste was printed. On the glass-ceramic composite substrate sheet, a dielectric green sheet on which a conductive paste is printed so as to have a predetermined lamination number is laminated, and further, an unprinted glass-ceramic composite substrate green sheet is laminated and fired. I do. Then, after firing, an end electrode paste is formed in a predetermined pattern on the surface of the glass-ceramic composite substrate and fired to form an end electrode. The end electrode is
It may be fired simultaneously with the glass-ceramic composite substrate or the dielectric layer.

The substrate material that becomes the glass-ceramic composite substrate upon firing contains an oxide aggregate and glass powder.

The glass powder used as the substrate material, that is, the glass composition for a substrate containing a lead-based dielectric according to the present invention (a glass composition which does not decompose the lead-based perovskite compound) is composed of Al ₂ O ₃ , CaO and SiO _2. Become.

The content of Al ₂ O ₃ is 10 to 35 mol%, preferably 10 to 20 mol%. When the content of Al ₂ O ₃ is out of the above range, the glass is easily crystallized and the substrate cannot be fired densely.

The content of CaO is 20 to 60 mol%, preferably 20 to 35 mol%. If the content of CaO is outside the above range, the glass tends to crystallize, and the substrate cannot be fired densely.

The content of SiO ₂ is 8 to 40 mol%, preferably 15 to 40 mol%. Below the lower limit of the above range, the glass tends to crystallize and the substrate cannot be fired densely. If the upper limit of the above range is exceeded, the lead-based dielectric will be decomposed by SiO ₂ in the glass composition.

The glass powder used as the substrate material preferably further contains at least one oxide selected from MgO, BaO and SrO. This is because glass is difficult to crystallize and becomes stable. Its content is 30 mol% or less. The composition in this case is M
gO 10-20 mol%, BaO 5-15 mol%, SrO
It is preferable that the content be in the range of 0 to 5 mol%.

It is preferable that TiO _{2 be} further contained. This is because the softening point of the glass can be lowered, and the glass is hardly crystallized and becomes stable. Its content is at most 10 mol%, preferably at most 5 mol%. The lower limit of the amount added is preferably 1 mol%. If the ratio exceeds the above range, crystallization tends to occur, and if the ratio is less than the above lower limit, the effect on glass stability decreases.

The average particle size of the glass powder is about 1 to 3 μm in consideration of moldability and the like.

The content of the glass powder with respect to the entire substrate material is preferably 60 to 90% by volume. If the glass powder is too small, the sinterability tends to deteriorate, and if it is too large, the transverse rupture strength of the glass-ceramic composite substrate tends to decrease.

Examples of the oxide aggregate include one or more of Al ₂ O ₃ , forsterite, mullite, cordierite and the like. In this case, the oxide aggregate used may have a composition slightly deviating from the stoichiometric composition, or may be a mixture with a composition having a deviation or a mixture of compositions having a deviation.

As a preferable combination of the glass powder and the oxide aggregate, Al ₂ O ₃ is used as the oxide aggregate,
These amounts include a combination of 20 to 30% by volume of the Al ₂ O ₃ component and 70 to 80% by volume of the glass component.

Here, Al ₂ O ₃ is contained in both the glass composition and the aggregate, but the Al ₂ O ₃ contained in each does not affect each other.

The average particle size of the oxide aggregate is 0.5 to 3 μm.
It is preferred that it is about. If the average particle size is too small, sheet molding tends to be difficult, and if too large, the strength of the glass-ceramic composite substrate tends to be insufficient.

The oxide aggregate and glass powder are made into a slurry by adding a vehicle, and this slurry is formed, dried, and made into a green sheet. The vehicle includes a binder and a solvent. As the binder, ethyl cellulose,
Examples include polyvinyl butyrate, methacrylic resin, and butyl methacrylate. Examples of the solvent include terpineol, butyl carbitol, butyl carbitol acetate, toluene, alcohol, xylene, and the like.
In addition, various dispersants, activators, plasticizers and the like are added to the vehicle as required. The vehicle content in the slurry is preferably about 10 to 20% by weight.

The thickness of the glass-ceramic composite substrate is
Preferably it is 30 to 300 μm. If the glass-ceramic composite substrate is too thin, the bending strength becomes insufficient and handling becomes difficult, and if it is too thick, the binder removal property deteriorates.

On the other hand, as a dielectric material incorporated in the substrate, a lead-based perovskite compound is used. Pb (Mg _1/3 Nb) in stoichiometric composition among lead-based perovskite compounds
_2/3 ) O ₃ , Pb (Fe _1/3 W _2/3 ) O ₃ , Pb (Fe _1/3 N
Since b _2/3 ) O ₃ is particularly easily decomposed, it is useful to use the glass composition according to the present invention when at least one of these is used. Further, as the dielectric material, PbTiO ₃ ,
A material to which CuO, PbO, a lead silicate compound, Ag, or the like is added may be used. PbTiO ₃ raises the Curie temperature, CuO, PbO, lead silicate compound, Ag
Improves sinterability. When these compounds are added, the content of the lead-based perovskite compound is preferably 7
It is at least 0% by weight, especially 70 to 95% by weight. If the content is less than 70% by weight, a high dielectric constant cannot be obtained. The lead-based perovskite compound may slightly deviate from the stoichiometric composition. Particularly, in order to improve the sinterability of the dielectric material, it is preferable to include a lead silicate compound among the above additives. Here, the lead silicate compound is an amorphous glass or crystallized glass containing SiO ₂ and PbO as main components.

As the lead silicate compound, SiO _2-
PbO-Al ₂ O ₃ compound or SiO ₂ -PbO-Al ₂ O
It is preferable to use a _3- CuO compound. Its content is 3 to 20% by weight.

The SiO ₂ —PbO—Al ₂ O ₃ compound is represented by S
iO ₂ eighteen to forty-three mol%, more preferably 28 to 37 mol%, PbO55～80 mol%, more preferably 58 to
It is 62 mol%, Al ₂ O ₃ 1-5 mol%, and more preferably 1.5-3.5 mol%.

If the amount of SiO ₂ is too small, the liquid phase formation temperature becomes high and the effect as a sintering aid decreases, and if it is too large, the lead-based perovskite compound is easily decomposed.

If the amount of PbO is too small, the lead-based perovskite compound will be easily decomposed, and if the amount is too large, the contents of other essential components, SiO ₂ and Al ₂ O ₃ , will decrease, and the sintering aid will be reduced. The effect is reduced.

If the amount of Al ₂ O ₃ is too small, the effect of lowering the liquid phase generation temperature is not so high. If the amount is too large, the liquid phase generation temperature becomes high and the effect as a sintering aid decreases.

A compound obtained by adding CuO to the above-mentioned lead silicate compound, that is, SiO ₂ —PbO—Al ₂ O ₃ —
The CuO compound is composed of 10 to 40 mol% of SiO ₂ , more preferably 25 to 35 mol%, 50 to 75 mol% of PbO, more preferably 55 to 65 mol%, and 1 to 15 mol% of Al ₂ O ₃ , more preferably 3 to 35 mol%. ４4 mol%, CuO 1-20 mol%, more preferably 1.5-17 mol%.

SiO ₂ , PbO, and Al ₂ O ₃ are for the same reason as described above, and CuO also has a role as a sintering aid. If the content is too small, the effect of lowering the liquid phase formation temperature is reduced. This is because when the content is too large, the liquid phase formation temperature increases, and the effect as a sintering aid decreases.

The lead silicate compound to which CuO is added is partially substituted with AgO _1/2 , that is, SiO
The compound obtained by adding CuO and AgO _1/2 to the O ₂ —PbO—Al ₂ O ₃ compound also has the same effect as the compound obtained by adding only CuO. The content of CuO and AgO _1/2 is Cu
It may be equivalent to the amount when O alone is added, but is preferably 3 to 8 mol%. At this time, the content of CuO is preferably 2 to 6 mol%.

The content of the lead silicate compound is preferably from 3 to 20% by weight. If the content is too small, the effect of addition, that is, no improvement in sinterability is observed, and if the content is too large, the dielectric constant decreases.

The average particle size of the lead-based perovskite compound and the lead silicate compound is preferably 0.1 to 10 μm. If the average particle size is too small, the binder removal properties will deteriorate, and if it is too large, the sinterability will deteriorate.

The dielectric slurry that becomes a dielectric layer by firing contains a dielectric material and a vehicle.

The vehicle of the dielectric slurry includes glass-
What is mentioned in the description of the slurry for the ceramic composite substrate may be used.

The thickness of the dielectric layer may be appropriately determined according to the desired capacitance, etc., but is preferably 10 to 60 μm.
m. If the dielectric layer is too thin, it becomes difficult to form a uniform layer. On the other hand, if the dielectric layer is too thick, the multilayer substrate becomes thick, and it is difficult to reduce the size.

The conductive paste which becomes the electrode layer by firing is as follows:
Contains conductor powder and vehicle.

Since the conductor powder has good conductivity and is inexpensive, Ag particles, a mixture of Ag particles and Pd particles, or Ag-Pd alloy particles or Ag-Pd alloy particles or Ag particles and / or Pd particles are used. Is preferably used. The content of each metal with respect to the entire conductor powder is preferably Ag: 80 to 100% by weight Pd: 0 to 20% by weight. If the amount of Ag is too small, the resistance increases. Although Pd is not essential, the inclusion of Pd reduces the migration of Ag, and the inclusion of Pd increases the sintering temperature of the conductor paste. Therefore, it is effective when the firing temperature of the glass-ceramic composite substrate is relatively high. . The average particle size of the conductor powder (the average of the major axis diameter when the particle shape has anisotropy) is not particularly limited, but may be generally about 0.1 to 5 μm. Although the particle shape is not particularly limited, it is generally preferable to be spherical.
However, some or all of the conductive particles may be in a scale shape.

In the vehicle of the conductor paste, an acrylic resin may be used as a binder, and terpineol and butyl carbitol acetate may be used as a solvent.

The thickness of the electrode is not particularly limited.
It is about 3 to 20 μm.

The firing may be usually performed in the air. The firing temperature is preferably set to 800 ° C. or higher, and may be determined appropriately according to the composition of the conductor powder. The firing time is usually about 10 to 30 minutes. The firing may be performed plural times.

In the illustrated example, there is only one dielectric layer.
A configuration in which two or more dielectric layers are provided may be employed.

Further, as shown in FIG. 2, a substrate containing the glass composition for a substrate containing a lead-based dielectric which does not decompose the lead-based perovskite compound may be used as a buffer layer to prepare a substrate. That is, in FIG.
41 is sandwiched between the electrodes 151 and 152 to form a capacitor portion, and the buffer portions 131 and 132 containing the glass composition for a substrate containing a lead-based dielectric that does not decompose the lead-based perovskite compound according to the present invention. Sandwiched between
And a glass-ceramic composite substrate 12 having a conventional composition.
1, 122. End electrodes 161 and 162 are provided on the outer surface, respectively, and these end electrodes are connected to the internal electrodes 151 and 152, respectively.

The multilayer substrate having the buffer layer of the present invention is usually
It is manufactured by a printing method or a sheet method. In the printing method, a conductor paste and a dielectric paste are alternately printed on a green sheet of a buffer material in a predetermined number of layers. Next, the green sheet of the glass-ceramic composite substrate, the green sheet of the buffer material not printed, the green sheet of the printed buffer material, and the green sheet of the glass-ceramic composite substrate are laminated and fired in this order. On the other hand, in the sheet method, a conductor sheet is printed on a green sheet of a dielectric material, and a conductor paste is printed on a green sheet of a cushioning material.
A green sheet of a buffer material, a green sheet of a dielectric material printed with a conductive paste, a green sheet of a buffer material printed with a conductive paste, and a green sheet of a glass-ceramic composite substrate are laminated in this order and fired. Then, after firing, an end electrode paste is formed in a predetermined pattern on the surface of the glass-ceramic composite substrate and fired to form an end electrode. The end electrodes may be fired at the same time as the glass-ceramic composite substrate or the dielectric layer.

In addition to the composition of the buffer material, various conditions such as the raw material particle size, the vehicle composition used for forming the paste, the thickness of the buffer layer, and the like are determined so that the glass-ceramic composite does not decompose the lead-based perovskite compound. The conditions may be the same as those of the substrate.

The conditions such as the composition of the dielectric to be incorporated and the electrode paste are the same as those of the multilayer substrate with a built-in capacitor.

In the multilayer substrate with a built-in capacitor having a buffer layer, any material can be used as a substrate material for forming a glass-ceramic composite substrate by firing, as long as it can be fired simultaneously with an electrode containing Ag as a main component. A material containing glass powder is used.

The glass powder used as the substrate material is not particularly limited, and may have a usual composition conventionally used for a glass-ceramic composite substrate. Specifically, taking into account the bending strength of the glass-ceramic composite substrate, wettability to oxides, adhesion to end electrodes, and the like,
For example, a glass having a softening point of about 750 to 850 ° C. may be appropriately selected. As such a glass powder, for example,
SiO disclosed in JP-A-1-122194
_{2 -SrO-Al 2 O 3 -B} 2 O 3 -CaO-BaO based glass composition, and the like.

The oxide aggregate is not particularly limited. For example, Al ₂ O ₃ , forsterite, quartz, mullite, cordierite, R ₂ Ti ₂ O ₇ (R is one of the lanthanoid elements)
Species), Ca ₂ Nb ₂ O ₇ , MgTiO ₃ , SrZr
O ₃ , TiO ₂ , SnO ₂ · TiO ₂ , ZrTiO ₄ , Ba ₂
Ti ₉ O ₂₀ , Sr ₂ Nb ₂ O ₇ , CaTiO ₃ , SrTi
_{O 3, SrSnO 3, BaO ·} R 2 O 3 · nTiO 2 (R is one or more lanthanoids), and the like or two or more one without the system, or the like. In this case, the oxide aggregate used may be a mixture with a composition slightly deviating from the stoichiometric composition or a mixture of compositions having a deviated composition.

The average particle size of the oxide aggregate is generally 0.5 to
It is preferably about 3 μm. If the average particle size is too small, sheet forming tends to be difficult, while if too large, the strength of the glass-ceramics substrate tends to be insufficient.

A vehicle is added to the oxide aggregate and the glass powder to form a slurry, and this slurry is formed and dried to obtain a green sheet. As the vehicle, those described in the description of the slurry of the substrate containing the glass composition for a substrate containing a lead-based dielectric that does not decompose the lead-based perovskite compound may be used.

In the multilayer substrate with a built-in capacitor having a buffer layer, the thickness of the glass-ceramic composite substrate is preferably 30 to 300 μm. If the thickness of the glass-ceramic composite substrate is too small, the bending strength becomes insufficient and handling becomes difficult. On the other hand, if it is too thick, the binder removal property will be poor.

In the illustrated example, there is only one dielectric layer.
A configuration in which two or more dielectric layers are provided may be employed.

[0067]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.

Example 1 A multilayer substrate with a built-in capacitor having the structure shown in FIG.
A multilayer substrate with a built-in capacitor using a glass-ceramic composite substrate containing a glass composition that does not decompose the lead-based perovskite compound even when co-fired was prepared as follows.

(Glass Composition) Each raw material (oxide) was weighed so as to have a composition as shown in Table 1, and mixed using a shaker mixer. This mixture is melted in a crucible at 1500 to 1600 ° C. for 30 minutes to 5 hours (appropriately selected from this range depending on the glass composition), quenched with water, dry-ground with a grinder, and then ball-milled (in ethanol). A glass composition powder having an average particle size of about 1.6 μm was obtained.

Here, the glass No. in Table 1 was used. 1 to No.
The composition having the composition No. 24 is the glass composition for a lead-based dielectric-containing substrate according to the present invention. 25 and 26 are conventional glass compositions.

In the table, “Presence” and “No” of “decomposition” were evaluated as follows.

When a glass-ceramic composite substrate and a lead-based perovskite compound are simultaneously fired using a conventional glass composition, the SiO ₂ in the substrate and the lead-based perovskite compound react to decompose, but EPMA (Electron Probe Mic) is used.
ro Analyzer), the diffusion amount of SiO ₂ from the substrate to the lead-based perovskite compound was 6 wt.
%. Therefore, the glass composition corresponding to the amount of SiO ₂ diffusion was added to the lead-based perovskite compound, and the substrate was fired in a firing pattern to determine whether the lead-based perovskite compound was decomposed by X-ray diffraction.

Glass crystallization temperature Tx and softening temperature Ts
Was measured by TG-DTA.

[0074]

[Table 1]

(Green Sheet for Glass-Ceramic Composite Substrate) 30% by volume of Al ₂ O ₃ and 70% by volume of Table 1
After adding a vehicle to the glass powder of the glass composition of the above and kneading the mixture, forming the mixture into a sheet by a doctor blade method,
After drying, a green sheet having a thickness of about 250 μm was prepared. The vehicle used was an acrylic resin as a binder, ethyl alcohol and toluene as a solvent, and phthalate as a plasticizer.

(Conductor paste) Conductor powder (average particle size: 3.
The vehicle was added to a 5 μm Ag powder) and kneaded with a three-roll mill to form a paste. As the vehicle, an acrylic resin was used as a binder, and terpineol and butyl carbitol acetate were used as solvents.

(Dielectric Sheet) 95 mol% Pb (Mg _1/3 Nb _2/3 ) O ₃ -5 mol% PbTiO ₃ as a dielectric material
10 parts by weight of PbO and 0.3 parts by weight of Cu0 (dielectric A) or 7 parts by weight of a lead-based glass (lead silicate in Table 3) Compound No. 101) (dielectric B)
Was used. A vehicle is added to the dielectric material, kneaded, and formed into a sheet by a doctor blade method.
After drying, a green sheet having a thickness of about 60 μm was prepared.
The vehicle used was an acrylic resin as a binder, ethyl alcohol and toluene as a solvent, and phthalate as a plasticizer.

(Method of Manufacturing Substrate) A conductive paste is printed on a green sheet and a dielectric sheet for a glass-ceramic composite substrate, and a green sheet for the glass-ceramic composite substrate and a conductive paste on which no conductive paste is printed are printed. Green sheet for glass-ceramic composite substrate without conductor, dielectric sheet with conductor paste printed, green sheet for glass-ceramic composite substrate with conductor paste printed, green sheet for glass-ceramic composite substrate without conductor paste printed The sheets are laminated in the order of
The multilayer substrate sample was obtained by baking at 0 ° C. for 10 minutes.

An external conductor paste was applied to the side surface of the multilayer substrate sample, and the end electrodes were baked at 850 ° C. for 10 minutes. 1 to No. A multilayer substrate sample incorporating 29 capacitors was prepared (FIG. 1).

For comparison, a glass using a glass composition conventionally used as a glass for a low-temperature fired substrate (a glass composition in which the proportion of SiO ₂ exceeds 40 mol%) was used.
Multilayer substrate sample (No. 30 shown in Table 2) incorporating a capacitor manufactured using a ceramic composite substrate sheet
-No. 32) was also prepared.

(Evaluation Method and Evaluation Results) The relative dielectric constant (ε) at 1 kHz of the dielectric layer was measured for each sample. The measurement was performed at room temperature using an LCR meter (HP-4284).
A Hewlett-Packard).

Table 2 shows the measurement results for each sample.

The effects of the present invention are clear from the results of the above examples. That is, while the relative dielectric constant of the dielectric co-fired with the glass-ceramic composite substrate using the conventional glass composition is about 500 to 2,000, the dielectric co-fired with the glass-ceramic composite substrate of the present invention is Has a remarkably improved dielectric constant of about 5000 to 11000.

[0084]

[Table 2]

Example 2 In Example 1, a capacitor having the structure shown in FIG. 1 was built by using a dielectric material containing a lead-based perovskite compound and a lead silicate compound having a high dielectric constant of the dielectric after co-firing. A multilayer substrate was manufactured. Here, a lead silicate compound having a composition as shown in Table 3 was prepared.

[0086]

[Table 3]

(Dielectric Sheet) 95 mol% Pb (Mg _1/3 Nb _2/3 ) O ₃ -5 mol% PbTiO ₃ as a dielectric material
(Average particle size: 1.0 μm) 7 parts by weight of the lead silicate compound shown in Table 3 (Table 3 Lead silicate N
o. 101 to 121) (Table 3 Dielectric B to
V) was used. In the case of using a lead silicate compound containing no CuO, 0.3 parts by weight of CuO was further added.
Was added. A vehicle is added to the dielectric material, kneaded, and formed into a sheet by a doctor blade method.
After drying, a green sheet having a thickness of about 60 μm was prepared.
The vehicle used was an acrylic resin as a binder, ethyl alcohol and toluene as a solvent, and phthalate as a plasticizer.

(Green Sheet for Glass-Ceramic Composite Substrate) A vehicle was added to a glass powder of 30% by volume of Al ₂ O ₃ and 70% by volume of a glass composition, kneaded, and formed into a sheet by a doctor blade method. Thereafter, drying was performed to produce a green sheet having a thickness of about 250 μm. The vehicle used was an acrylic resin as a binder, ethyl alcohol and toluene as a solvent, and phthalate as a plasticizer. Here, the composition of the glass used is shown in Table 1.
Glass no. 18, ie, 29.7 mol% of SiO ₂ , 13.6 mol% of Al ₂ O ₃ , 27.1 mol% of CaO,
16.6 mol% of MgO, 10.0 mol% of BaO, TiO
₂ 3.0 mol%.

The composition and production method of the conductor paste, the production method of the substrate, and the like are the same as those in the first embodiment.

(Evaluation Method and Evaluation Results) The relative dielectric constant (ε) at 1 kHz of the dielectric layer was measured for each sample. The measuring device is the same as in the first embodiment.

Table 4 shows the measurement results for each sample.

The effects of the present invention are clear from the results of the above examples. That is, Pb (Mg) is used as a dielectric material.
_{The one} using _1/3 Nb _2/3 ) O ₃ -PbTiO ₃ -PbO had a sufficient effect as described above (the dielectric constant was about 650).
0), a lead silicate compound according to claim 7 or 8 instead of PbO in said dielectric material, ie SiO 2
₂ 18-43 mol%, PbO 55-80 mol%, Al ₂ O
_{31 to} 5 mol% of a lead silicate compound or SiO ₂
40 mol%, PbO 50-75 mol%, Al ₂ O ₃ 1-1
The relative permittivity of the dielectric co-fired with the glass-ceramic composite substrate using a lead silicate compound containing 5 mol% and CuO 1 to 20 mol% is as follows:
It was further improved to about 7200 to 12500 and about 6700 to 11500. It should be noted that the specific permittivity was also improved when a part of CuO was replaced with AgO _1/2 .

[0093]

[Table 4]

Example 3 A multilayer substrate with a built-in capacitor having the structure shown in FIG.
A multilayer substrate with a built-in capacitor having a buffer layer was manufactured as follows.

(Method for Producing Substrate Having Buffer Layer) On a buffer material green sheet, a conductor paste was printed, then a dielectric paste was printed, and the conductor paste was printed. The sheets are laminated in the following order: a green sheet for a glass-ceramic composite substrate, a buffer green sheet on which no paste is printed, a buffer green sheet on which a conductor paste and a dielectric paste are printed, and a green sheet for a glass-ceramic composite substrate. Crimped by press and 9
Baking was performed at 00 ° C. for 10 minutes to obtain a multilayer substrate sample.

An external conductor paste was applied to the side surface of the multilayer substrate sample, and the end electrodes were baked at 850 ° C. for 10 minutes. 53-No. A multilayer substrate sample containing 81 capacitors was prepared (FIG. 2).

Here, the glass composition used for the buffer material is the same as the glass composition according to Example 1, that is, the glass composition shown in Table 1. The method for producing the buffer material green sheet was the same as that for the glass-ceramic composite substrate green sheet of Example 1, and the conductor paste used was the same as that for Example 1. The dielectric paste was made into a paste by adding a vehicle to the dielectric material having the composition of Example 1 and kneading with a three-roll mill. For the vehicle, an acrylic resin was used as a binder, and terpineol and butyl carbitol acetate were used as solvents.

The green sheet for a glass-ceramic composite substrate has a conventional composition of 30% by volume of Al.
₂ O ₃ and 70% by volume of SiO ₂ —SrO—Al ₂ O ₃ —B ₂
A vehicle was added to the glass powder of the O ₃ —CaO—BaO glass composition, kneaded, formed into a sheet by a doctor blade method, and then dried to produce a green sheet having a thickness of about 250 μm. The vehicle used was an acrylic resin as a binder, ethyl alcohol and toluene as a solvent, and phthalate as a plasticizer.

For comparison, a multilayer substrate sample (No. 82 and No. 83 shown in Table 5) in which a capacitor was directly built in the glass-ceramic composite substrate having the above-mentioned conventional composition, that is, the lead-based perovskite compound according to the present invention was used. A capacitor with a built-in capacitor (without a buffer layer) without a substrate containing a glass composition for a substrate with a lead-based dielectric that does not decompose was also prepared.

(Evaluation Method and Evaluation Results) The evaluation method was also the same as in Example 1 for each sample.
The relative dielectric constant (ε) at z was measured. The results are shown in Table 5.

The effects of the present invention are clear from the results of the above examples. That is, the relative permittivity of a dielectric obtained by co-firing a glass-ceramic composite substrate of a conventional composition with a built-in capacitor directly (No. 82, N
o. 83) is about 500, but the dielectric constant of a dielectric obtained by co-firing a capacitor with a built-in capacitor (as a buffer layer) via the glass-ceramic composite substrate of the present invention is remarkably improved to about 5000 to 12000. did.

Of course, in the glass-ceramic composite substrate having this buffer layer, when the lead-based perovskite compound containing the above-mentioned lead silicate compound is used as the dielectric material, a high dielectric constant is maintained even after simultaneous firing. Needless to say.

[0103]

[Table 5]

[0104]

The glass composition for a substrate with a built-in lead-based dielectric according to the present invention uses a glass composition which does not decompose the lead-based perovskite compound even when fired simultaneously with the lead-based perovskite compound. Therefore, the glass using this glass composition
Decomposition of the lead-based perovskite compound incorporated in the ceramic composite substrate is suppressed, and an original high dielectric constant is obtained.

Further, by including a lead silicate compound in the dielectric material contained therein, the sinterability of the lead-based perovskite compound can be increased and the dielectric constant of the dielectric material contained therein can be increased.

In the present invention, a substrate material containing a glass composition that does not decompose the lead-based perovskite compound is provided as a buffer layer between the capacitor part and the glass-ceramic composite substrate that decomposes the dielectric. This also does not decompose the lead-based perovskite compound, so the decomposition of the lead-based perovskite compound is suppressed,
A high dielectric constant is obtained.

Therefore, since the built-in dielectric has a high dielectric constant, the size of the substrate can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a configuration example of a multilayer substrate having a built-in capacitor unit according to the present invention.

FIG. 2 is a partial cross-sectional view showing another configuration example of a multilayer substrate incorporating a capacitor section according to the present invention.

[Explanation of symbols]

21, 22, 23, 24: Glass-ceramic composite substrate 31: Dielectric 41, 42: Internal electrode 51, 52: End electrode 121, 122: Glass-ceramic composite substrate 131, 132: Buffer layer 141: Dielectric 151 , 152: internal electrode 161, 162: end electrode

Claims (10)

[Claims] (1) Al ₂ O ₃ 10 to 35 mol%, CaO 20 to
A glass composition for a lead-based dielectric-containing substrate, comprising 60 mol% and 8 to 40 mol% of SiO ₂ . 2. The glass composition for a lead-based dielectric-containing substrate according to claim 1, wherein the glass composition contains at least one oxide selected from MgO, BaO and SrO in an amount of 30 mol% or less. 3. The glass composition for a substrate containing a lead-based dielectric according to claim 2, which contains 10 mol% or less of TiO ₂ . 4. A glass-ceramic composite substrate composition comprising 60 to 90% by volume of the glass composition for a lead-containing dielectric substrate according to any one of claims 1 to 3. 5. A multilayer substrate with a built-in capacitor, wherein the substrate composition according to claim 4 and a lead-based dielectric composition are co-fired. 6. The multilayer substrate with a built-in capacitor according to claim 5, wherein said lead-based dielectric composition contains at least a lead-based perovskite compound and a lead silicate compound. 7. The composition of the lead silicate compound is SiO ₂
18-43 mol%, PbO 55-80 mol%, Al ₂ O ₃
The multilayer substrate with a built-in capacitor according to claim 6, wherein the content is 1 to 5 mol% and the content is 3 to 20% by weight. 8. The composition of the lead silicate compound is SiO ₂
10 to 40 mol%, PbO 50 to 75 mol%, Al ₂ O ₃
The multilayer substrate with a built-in capacitor according to claim 6, wherein the content is 1 to 15 mol% and CuO is 1 to 20 mol%, and the content thereof is 3 to 20 wt%. 9. The composition of the lead silicate compound is SiO ₂
10 to 40 mol%, PbO 50 to 75 mol%, Al ₂ O ₃
The multilayer substrate with a built-in capacitor according to claim 6, wherein the content is ₁ to 15 mol%, CuO + AgO1 _{/ 2 is} 1 to 20 mol%, and the content is 3 to 20 wt%. 10. A multilayer substrate having a built-in capacitor portion having a dielectric layer and an electrode layer between a pair of glass-ceramic composite substrates and having a buffer layer between the capacitor portion and each glass-ceramic composite substrate. The dielectric layer contains a lead-based perovskite compound, and is used as a buffer layer.
A multilayer substrate with a built-in capacitor, characterized by using a substrate comprising the glass-ceramic composite substrate composition of (1).