JP2001097773A - Method for producing dielectric porcelain composition and method for producing electronic part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a dielectric porcelain composition which can be sintered at a temperature of <=1,250 deg.C in a non-oxidizing atmosphere, is not converted into a semi-conductor, has a high dielectric constant and high insulating resistance, and is small in dielectric loss, and to provide an electronic part using the composition. SOLUTION: This method for producing a dielectric porcelain composition has a process for producing a main component containing a dielectric oxide having a composition represented by Ba(1-x)Cax}O}A(Ti(1-y)Zry)BO2, a process for producing a subsidiary component containing one or more substances selected from the oxides of Sr, Y, Gd, Tb, Dy, V, Mo, Zn, Dd, Ti, Sn, W, Mn, Si and P, and a process for adding (BazCa(1-z))SiO3 [provided that (z)=0 to 1] to the main component and/or the subsidiary component so that the subsidiary component is contained in an amount of 0.001 to 5 mol.% in terms of the oxides on the basis of the total amount of the composition and so that the symbols A, B, (x), and (y) have the relations: 0.990<=A/B<1.000, 0.01<=(x)<=0.25, and 0.1<=(y)<=0.3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a dielectric ceramic composition used as a dielectric layer of an electronic component such as a multilayer ceramic capacitor, and a method for producing an electronic component.

[0002]

2. Description of the Related Art Conventionally, a multilayer ceramic capacitor has
A conductive paste is printed on a green sheet made of a predetermined dielectric porcelain composition, a plurality of green sheets printed with the conductive paste are laminated, and the green sheet and the internal electrode are integrally fired to be formed. I have. And conventionally,
As a non-reducing dielectric ceramic composition in which a base metal can be used as an internal electrode, for example, a ceramic capacitor having a high capacity as disclosed in Japanese Patent Application Laid-Open No. 5-86679 is known.

[0003] The dielectric ceramic composition disclosed in this _{publication, {(Ba (1-x} ) Ca x Sr y) O} A
As a main component a dielectric oxide represented by _{(Ti (1-z) Zr} z) B O 2. However, 1.000 ≦ A
/B<1.020, 0.01 ≦ x ≦ 0.25, 0 ≦ y ≦
0.05, 0.05 ≦ z ≦ 0.20.

However, this dielectric porcelain composition can suppress a reduction reaction of a dielectric material generated during firing, but requires a high firing temperature of 1220 ° C. or more for firing. There is a problem in that the internal electrodes are likely to be thick and interrupted. Also,
When Ni is used as the internal electrode of the multilayer capacitor,
Ni particles show an agglutination reaction, and it is difficult to form a stable electrode. In this dielectric porcelain composition, A in the main component
/ B is 1 or more, and there is a problem that low-temperature firing is difficult.

In recent years, dielectric porcelain which can be fired at a low temperature has recently been developed.
As the composition, JP-A-10-279353,
JP-A-6-14496 and JP-A-4-36755
No. 9 is known. Special public
Japanese Patent Application Laid-Open No. Hei 6-14496 discloses a_(1-x)C
a_x) O｝_m(Ti_(1-yz)Zr_yR
_z) O_{2-z / 2} And a main component represented by
₂, Li₂O and MO (MO is BaO etc.)
Ceramic composition obtained by firing a mixture with an additive component
Is disclosed. However, R in the main component is a rare earth such as Y
And 1.00 ≦ m ≦ 1.04.

According to this publication, the main component is calcined at 1200 ° C., the additional component is calcined at 1000 ° C., the main component and the calcined powder of the additional component are mixed, and a slurry is formed from the mixed powder. It is disclosed that a sintered body can be obtained by molding into a predetermined shape and firing at 1150 ° C.

Further, Japanese Patent Application Laid-Open No. Hei 4-369559 discloses
Is (Ba_(1-x)Ca_x)_m (Ti
_(1-y)Zr_y)_nO₃+ AM1 + bM2 +
A porcelain composition represented by cM3 is disclosed. However
M1 is a compound such as Mn, M2 is a compound of Si, M3
Is a compound of Y.

In this publication, BaCO ₃ , CaCO _3
3 , TiO ₂ , ZrO ₂ , SiO ₂ , Y ₂ O
_{3 and the} like are mixed.
C. and calcined at this temperature to produce a compact using this calcined powder.
It is disclosed that a sintered body can be obtained by firing at 300 to 1400 ° C. In these dielectric ceramic compositions, the porcelain is not reduced even when fired in a reducing atmosphere, the firing temperature can be set to 1150 ° C. or less, and low-temperature firing is possible.

Further, _{JP-A-10-279353, {(Ba (1-} x) Ca x) O} A (Ti
_(1-y) Zr _y) the B _{O 2} as a main component, Y,
A dielectric porcelain composition containing an oxide of Li, B or Si as an auxiliary component is disclosed. However, 0.990 ≦ A
/B<1.02, 0.01 ≦ x ≦ 0.10, 0.15 ≦
y ≦ 0.25. However, in the dielectric porcelain composition disclosed in this publication, since Li is contained in the composition, Li evaporates during firing and contaminates the furnace, greatly affecting the composition of the composition. As a result, there is a problem that the electrical characteristics of the resulting sintered body deteriorate.

Further, _{JP-A-11-130531, {(Ba (1-} x) Ca x) O} A (Ti
_(1-y) Zr _y) the B _{O 3} as a main component, Y,
A dielectric porcelain composition containing oxides of Si, Ba and Ca as subcomponents is disclosed. However, 0.98 ≦ A
/B<1.01, 0.01 ≦ x ≦ 0.10, 0.15 ≦
y ≦ 0.25. However, the dielectric porcelain composition disclosed in this publication has a problem in thinning,
There were problems such as a high firing temperature.

A multilayer ceramic chip capacitor is usually manufactured by laminating a paste for an internal electrode and a paste for a dielectric layer by a sheet method, a printing method or the like, and simultaneously firing them. Generally, Pd or a Pd alloy is used for the internal electrode, but since Pd is expensive, relatively inexpensive Ni or Ni alloy is being used. By the way, when the internal electrode is formed of Ni or a Ni alloy, the electrode is oxidized when firing in the air.

For this reason, generally, after the binder is removed, Ni is removed.
The baking is performed at an oxygen partial pressure lower than the equilibrium oxygen partial pressure of NiO and NiO. In this case, in order to densify the dielectric material,
Usually, SiO ₂ is added as a sintering aid. Also,
In order to prevent a decrease in insulation resistance due to reduction of the dielectric layer, addition of Mn, substitution with Ca, and the like are also performed.

However, a multilayer chip capacitor having an internal electrode made of Ni or a Ni alloy has a longer insulation resistance life than a multilayer chip capacitor having an internal electrode made of Pd manufactured by firing in air. There is a problem that it is overwhelmingly short and has low reliability.

However, the problem is that a dielectric oxide having a specific composition proposed by the present inventors is contained as a main component, and Y, Gd, Tb, Dy, Zr, V,
A dielectric material to which a specific amount of at least one selected from oxides of Mo, Zn, Cd, Ti, Sn and P and / or compounds that become these oxides after firing, and an internal electrode material of Ni or Ni alloy Almost all the problems could be solved by a laminated ceramic chip capacitor obtained by laminating and firing (Japanese Patent Laid-Open No. 3-133116). That is, as shown in this publication, when Y or the like is added as a sub-component, the life is increased by about 2 to 10 times as compared with the conventional chip capacitor having no added dielectric material, and the reliability is improved to some extent. Was obtained.

[0015]

However, a multilayer ceramic chip capacitor having a dielectric layer having the above composition has a problem that it is not densified below 1400.degree. By using SiO ₂ as the material, the above-described ceramic composition can be fired at a low temperature.

However, as in the prior art, the main component (A
/ B <1), when SiO ₂ is used as a sintering aid, there is a problem that the dielectric layer after firing is easily converted into a semiconductor, and electrical characteristics as a dielectric layer for a capacitor can be obtained. It has the problem of being difficult.

It is an object of the present invention to provide a non-oxidizing atmosphere for 125
Despite being capable of firing at temperatures below 0 ° C,
An object of the present invention is to provide a method for producing a dielectric ceramic composition which does not become a semiconductor, has a high dielectric constant and insulation resistance, and has a small dielectric loss, and a method for producing an electronic component using the dielectric magnetic composition. .

[0018]

SUMMARY OF THE INVENTION The present inventors have developed a dielectric ceramic composition used as a dielectric layer of an electronic component such as a multilayer ceramic chip capacitor. Production of a dielectric ceramic composition that enables firing at a lower temperature, further improves reliability, and enables the dielectric layer to be thinned to 10 μm or less due to the higher reliability. as a result of intensive studies about how, as the composition ratio of the dielectric ceramic composition is specific range, in the composition _{(Ba z Ca (1-z} )) Si
It has been found that the object of the present invention can be achieved by post-adding O ₃ , and the present invention has been completed.

[0019] That is, the production method of the dielectric ceramic composition according to the present _{invention, {{Ba (1-x} ) Ca x} O}
A step of preparing a main component containing _{A (Ti (1-y)} Zr y) dielectric oxide having a composition represented by B _{O 2,} S
r, Y, Gd, Tb, Dy, V, Mo, Zn, Cd, T
a step of producing a subcomponent containing at least one selected from oxides of i, Sn, W, Mn, Si, and P and / or compounds that become these oxides after firing; On the other hand, 0.001
Symbols A, B, x, and y each containing 5 mol% and indicating the composition ratio in the formula indicating the main component are 0.990 ≦ A / B <1.00.
0, 0.01 ≦ x ≦ 0.25, 0.1 ≦ y ≦ 0.3, the main component and / or the subcomponent have the following relationship:
_{(Ba z Ca (1-z} )) SiO 3 ( however, Z
= 0 to 1).

Further, the method for manufacturing an electronic component according to the present invention is characterized in that {Ba _(1-x) Ca _x {O} _A (Ti
_(1-y) Zr _y) a step of preparing a main component containing a dielectric oxide of a composition represented by _{B O 2, Sr, Y,} G
d, Tb, Dy, V, Mo, Zn, Cd, Ti, Sn,
Producing a subcomponent containing at least one selected from oxides of W, Mn, Si and P and / or compounds that become these oxides after firing; Symbols A and A, which are contained in an amount of 0.001 to 5 mol% in terms of oxide and indicate a composition ratio in a formula indicating the main component,
B, x, y are 0.990 ≦ A / B <1.000, 0.
The main component and / or the subcomponent have (Ba) such that the relation of 01 ≦ x ≦ 0.25 and 0.1 ≦ y ≦ 0.3 is satisfied.
_{z Ca (1-z))} SiO 3 ( however, Z = 0 to
1) a step of adding, a step of preparing a dielectric paste using powder obtained by mixing the main component and the subcomponent, a step of preparing a paste for internal electrodes, A step of alternately laminating the internal electrode paste to obtain a laminate, and a step of firing the laminate.

[0021] Preferably, the main component and / or secondary component, the _{(Ba z Ca (1- z)} ) SiO 3
Is added in a proportion of 0.01 to 3% by weight based on the whole composition.

Preferably, the laminate is fired at a temperature of 1250 ° C. or less.

Preferably, nickel or a nickel alloy is used as the internal electrode paste.

[0024]

[Action] {Ba _(1-x) Ca _x {O} _A (T
In _{i (1-y) Zr y} ) dielectric ceramic composition containing as a main component a dielectric oxide of a composition represented by B _{O 2,} in the case of A / B <1.000 is easily semiconductive after firing There is a problem that.

[0025] However, in the present invention, so as to have the composition ratio of the main components described above, the main component and / or auxiliary _{component, (Ba z Ca (1-} z)) SiO 3 ( however, Z = 0 to Since the baking step is performed after the addition of 1), the formation of a semiconductor can be prevented even when baking is performed at a low temperature.

That is, in the method for producing a dielectric ceramic composition according to the present invention, the dielectric ceramic composition can be fired at a low temperature of 1250 ° C. or less, and the relative dielectric constant and dielectric loss of the obtained dielectric layer can be reduced. , Breakdown voltage and insulation resistance are improved. Therefore, the electrical characteristics of electronic components such as a multilayer ceramic capacitor manufactured using the dielectric ceramic composition are improved.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the drawings. FIG. 1 is a sectional view of a main part of a multilayer ceramic capacitor according to an embodiment of the present invention.

[0028] Multilayer Ceramic Capacitor As shown in FIG. 1, a multilayer ceramic capacitor 1 as an electronic device according to an embodiment of the present invention, the configuration of the capacitor dielectric layers 2 and internal electrode layers 3 stacked alternately It has an element body 10. At both ends of the capacitor element body 10, a pair of external electrodes 4 are formed which are electrically connected to the internal electrode layers 3 alternately arranged inside the element body 10. The shape of the capacitor element body 10 is not particularly limited, but is generally a rectangular parallelepiped. In addition, the dimensions are not particularly limited, and may be appropriately determined according to the application.
Usually, (0.6 to 5.6 mm) x (0.3 to 5.0 m
m) × (0.3 to 1.9 mm).

The internal electrode layers 3 are laminated so that each end face is alternately exposed on the surfaces of two opposing ends of the capacitor element body 10. The pair of external electrodes 4 are formed at both ends of the capacitor element body 10 and connected to the exposed end faces of the alternately arranged internal electrode layers 3 to form a capacitor circuit.

Dielectric Layer 2 The dielectric layer 2 contains the dielectric ceramic composition of the present invention.
The dielectric porcelain composition of the present invention comprises ΔBa _(1-x) C
_{a x} O} A (Ti} (1-y) Zr y) B O
A main component containing a dielectric oxide having a composition represented by Formula ₂
r, Y, Gd, Tb, Dy, V, Mo, Zn, Cd, T
It has one or more, and preferably three or more, subcomponents selected from oxides of i, Sn, W, Mn, Si and P. In the present invention, the amount of oxygen (O) may slightly deviate from the stoichiometric composition of the above formula.

In the above formula, x is from 0.01 to 0.25, preferably from 0.05 to 0.10. Y is 0.1 or more and 0.3 or less, preferably 0.1 or more and 0.2 or less. A / B is 0.990 or more and less than 1.000, preferably 0.995 or more and 0.999.
It is as follows.

In this composition, x represents the number of Ca atoms, and this Ca mainly acts as a sintering stabilizer and also acts as an element for improving the insulation resistance value. When x is less than 0.01, the firing temperature becomes 1250.
° C or higher, and the insulation resistance value falls below 1 × 10 ⁷ Ω, and when x exceeds 0.25, the relative dielectric constant becomes 6
In any case, the basic characteristics of the multilayer ceramic capacitor are degraded. Therefore, the value of x is preferably in the range of 0.01 ≦ x ≦ 0.25.

In the above composition formula, y represents the number of atoms of Zr, and this Zr mainly acts as a shifter for moving the Curie point to a lower temperature side. If y is less than 0.1, the dielectric loss exceeds 15%, and y
Exceeds 0.3, the relative dielectric constant falls below 6000, and in any case, the basic characteristics of the multilayer ceramic capacitor deteriorate. Therefore, the value of y is preferably in the range of 0.1 ≦ y ≦ 0.3.

In the above composition formula, when A / B is less than 0.99, abnormal grain growth of the dielectric layer occurs during firing, and the insulation resistance value becomes less than 1 × 10 ⁷ Ω. If / B exceeds 1.00, the sinterability decreases, and a dense sintered body cannot be obtained. Therefore, A / B is 0.
The range of 99 ≦ A / B <1.00 is preferable.

In the present invention, the relationship described above is satisfied.
The main component and / or auxiliary component, _(Ba z Ca
By adding _(1-z) ) SiO ₃ (where Z = 0 to 1), low-temperature firing becomes possible without deteriorating the dielectric properties of the main component in the range of A / B <1. Poor reliability when the layers are thinned can be reduced, and the life can be extended.

In the present invention, when the content of the subcomponent is less than 0.001 mol% based on the whole composition, the sinterability is reduced, and a dense sintered body cannot be obtained. If it exceeds 5 mol%,
As a result, the insulation resistance value falls below 1 × 10 ⁷ Ω, and the basic characteristics of the multilayer ceramic capacitor cannot be satisfied. The sub-components are Sr, Y, Gd, Tb, D
y, V, Mo, Zn, Cd, Ti, Sn, W, Mn, S
One or more, preferably three or more selected from oxides of i and P and / or compounds that become these oxides after firing. This subcomponent, based on the total composition,
It is contained in an amount of 0.001 to 5 mol% in terms of oxide. By including such a subcomponent in the above mol% range, the high temperature load life of a ceramic capacitor having a dielectric layer obtained by firing the composition is improved.

Preferably, as an auxiliary component, an oxide of manganese and / or a compound which becomes an oxide upon firing,
0.03 to 2 mol%, preferably 0.2 to 1.3 mol%, more preferably 0.2 to 0.1 mol% in terms of oxide (MnO).
4 mol%, an oxide of yttrium and / or a compound which becomes an oxide by firing is converted to an oxide (Y ₂ O ₃ ) in an amount of 0.05 to 0.5 mol%, preferably 0.08 to 0.5 mol%.
0.45 mol%, more preferably 0.2 to 0.4 mol%, of an oxide of vanadium and / or a compound which becomes an oxide by firing is converted into an oxide (V ₂ O ₅ ),
0.005 to 0.5 mol%, preferably 0.01 to 0.
1 mol%, an oxide of tungsten and / or a compound which becomes an oxide by firing is converted into an oxide (WO ₃ ) in an amount of 0.005 to 0.3 mol%, preferably 0.01 to 0.3 mol%.
0.2 l%, more preferably about 0.01 to 0.1 mol%. By including such subcomponents in the above range, the sinterability particularly at low temperatures is improved. Further, in addition to the above subcomponents, Ni oxide, Nb oxide, Mg oxide, Co oxide, Hf oxide and the like may be contained in an amount of about 0.5% by weight or less in total of the subcomponents.

Further, the dielectric ceramic composition according to the present invention, the main component and / or auxiliary component, (Ba _z C
a _(1-z) ) SiO ₃ with respect to the entire composition
Preferably it is 0.01 to 3% by weight, more preferably 0.1% by weight.
It is added at a rate of 01 to 1% by weight. If the amount is too small, the semiconductor tends to be easily formed, and if the amount is too large, the insulation resistance tends to decrease.

In the present invention, the above-mentioned subcomponents are preliminarily 50
After calcining at 0 to 1000 ° C., a method of post-adding to the main component is desirable for low-temperature calcining.
and _{z Ca (1-z))} SiO 3, a method of post-added during the main component is further desirable for low-temperature firing.

The conditions such as the number of layers and the thickness of the dielectric layer 2 shown in FIG. 1 may be appropriately determined according to the purpose and application. The dielectric layer 2 is composed of grains and a grain boundary phase of 1% or less, and the average grain size of the grains of the dielectric layer 2 is as follows:
It is preferably about 1 to 5 μm.

The grain boundary phase usually contains an oxide of a material constituting the dielectric material or the internal electrode material, an oxide of a material added separately, or an oxide of a material mixed as an impurity during the process. As a component, it is usually made of glass or vitreous.

Internal Electrode Layer 3 The conductive material contained in the internal electrode layer 3 is not particularly limited, but a base metal can be used because the constituent material of the dielectric layer 2 has reduction resistance. As the base metal used as the conductive material, Ni or a Ni alloy is preferable. The Ni alloy is selected from Mn, Cr, Co and Al.
An alloy of at least one kind of element and Ni is preferable.
The content is preferably at least 95% by weight. In addition,
Ni or Ni alloy may contain various trace components such as P, Fe, and Mg in an amount of about 0.1% by weight or less. The thickness of the internal electrode layer may be appropriately determined according to the application and the like, but is usually preferably 0.5 to 5 μm, particularly preferably about 1 to 2.5 μm.

External electrode 4 The conductive material contained in the external electrode 4 is not particularly limited.
Usually, Cu, Cu alloy, Ni, Ni alloy, or the like is used. It should be noted that Ag and Ag-Pd alloy can also be used. In this embodiment, inexpensive Ni, Cu
Alternatively, these alloys are used. The thickness of the external electrode may be appropriately determined according to the application and the like.
It is preferred that it is about.

Method for Manufacturing Multilayer Ceramic Capacitor A multilayer ceramic capacitor using the dielectric ceramic composition of the present invention can be produced in the same manner as a conventional multilayer ceramic capacitor.
A green chip is produced by a normal printing method or a sheet method using a paste, fired, and then external electrodes are printed or transferred and fired. Less than,
The manufacturing method will be specifically described.

The dielectric layer paste may be an organic paint obtained by kneading a dielectric material and an organic vehicle, or may be an aqueous paint.

According to the composition of the dielectric porcelain composition according to the present invention described above, the raw material for the main component, the raw material for the subcomponent, and the sintering containing a part of the main component are used as the dielectric raw material. Raw materials constituting the auxiliary agent are used. As the raw material constituting the main component, oxides of Ti, Ba, Sr, Ca, and Zr and / or compounds that become oxides by firing are used. Sr, Y, G
d, Tb, Dy, V, Mo, Zn, Cd, Ti, Sn,
One or more, preferably three or more, single oxides or composite oxides selected from oxides of W, Mn, Si and P and / or compounds that become oxides upon firing are used. As a raw material containing a part of the main component and constituting the sintering aid, oxides of Ba, Ca, and Si and / or compounds that become oxides by firing are used. Examples of the compound that becomes an oxide upon firing include carbonates, nitrates, oxalates, and organometallic compounds. of course,
You may use together an oxide and the compound which turns into an oxide by baking.

These raw material powders usually have an average particle diameter of about 0.0005 to 5 μm. To obtain a dielectric material from such a raw material powder, for example, the following method may be used.

First, a starting material of a main component is prepared. The starting material of the main component is, for example, {Ba _(1-x) Ca _x {O} _A (Ti
It is _(1-y) Zr _y) powder B _{O 2.} Symbols A, B, x, y indicating the composition ratio in the formula in the starting material
Is not necessarily 0.990 ≦ A / B <1.000, 0.
It is not necessary to satisfy the relationship of 01 ≦ x ≦ 0.25 and 0.1 ≦ y ≦ 0.3. This is because it is added in a later step (B
By _{a z Ca (1-z)} ) SiO 3, because the composition ratio of the finally obtained dielectric ceramic composition is adjusted.

Next, sub-components are prepared. The minor component is S
r, Y, Gd, Tb, Dy, V, Mo, Zn, Cd, T
One or more, preferably three or more selected from oxides of i, Sn, W, Mn, Si and P and / or compounds that become these oxides after firing.

[0050] The above is added to the starting material and / or subcomponent _{(Ba z Ca (1-z} )) SiO 3 ( however, Z = 0 to 1) is, Ba, Ca, oxides of Si and / or baking The powder is obtained by mixing powder of a compound which becomes an oxide by the above method, dissolving the mixed powder in a crucible, quenching, vitrifying, and then pulverizing. _{Or, (Ba z Ca (1-} z)) SiO 3 is, B
It can also be obtained by calcination and then pulverization of powders of oxides of a, Ca, Si and / or compounds which become oxides by firing.

The calcination in this case is usually 500 to 1
At 300 ° C, preferably 1000-1200 ° C,
Perform in air for about 10 hours. Then, a jet mill or a ball mill, calcined product was pulverized to a predetermined particle _size, it is possible to obtain a powder of _{(Ba z Ca (1-z} )) SiO 3.

These starting materials, subcomponents and (Ba)
_z Ca _(1-z) ) SiO ₃ , after being mixed,
It is pulverized by a jet mill, a ball mill, or the like until it has a predetermined particle size, and becomes a dielectric material.

From this dielectric material, a dielectric layer paste is prepared. Various additives such as a binder, a plasticizer, a dispersant, and a solvent may be used when preparing the dielectric layer paste. Further, glass frit may be added to the paste for the dielectric layer. As the binder, for example, ethyl cellulose, resin abietic acid, polyvinyl butyral, etc., as the plasticizer, for example, abietic acid derivatives, diethyl oxalic acid, polyethylene glycol,
Examples of dispersants such as polyalkylene glycol, phthalate ester and dibutyl phthalate include glycerin, octadecylamine, trichloroacetic acid, oleic acid, octadiene, ethyl oleate, glyceryl monooleate, glyceryl trioleate, and glyceryl tristearate. , Mensaiden oil and other solvents
For example, toluene, terpineol, butyl carbitol, methyl ethyl ketone and the like can be mentioned. When the paste is fired, the ratio of the dielectric material to the entire paste is about 50 to 80% by weight, the binder is 2 to 5% by weight, the plasticizer is 0.01 to 5% by weight, The dispersant is 0.01 to 5% by weight, and the solvent is about 20 to 50% by weight. Then, the dielectric material and these solvents are mixed and kneaded with, for example, a three-roll mill or the like to form a paste (slurry).

In the case where the dielectric layer paste is an aqueous paint, an aqueous vehicle in which a water-soluble binder or dispersant is dissolved in water may be kneaded with a dielectric material. The water-soluble binder used for the aqueous vehicle is not particularly limited, and for example, polyvinyl alcohol, cellulose, a water-soluble acrylic resin, or the like may be used.

The internal electrode layer paste is obtained by kneading an organic vehicle with a conductive material made of various conductive metals or alloys, or various oxides, organometallic compounds, resinates, etc. which become the above-mentioned conductive material after firing. To be prepared.

As the conductor material used when producing the paste for the internal electrode, Ni, a Ni alloy, or a mixture thereof is used. Such a conductive material is not particularly limited in its shape, such as a sphere or a scale, and a mixture of these shapes may be used. The average particle diameter of the conductive material is usually 0.1 to 10 μm, preferably about 0.1 to 1 μm.

The organic vehicle contains a binder and a solvent. As the binder, any known binder such as ethyl cellulose, acrylic resin and butyral resin can be used. Binder content is 1
About 5% by weight. As the solvent, any of known solvents such as terpineol, butyl carbitol, and kerosene can be used. The solvent content is about 20 to 55% by weight based on the entire paste.

The paste for the internal electrode layer and the paste for the dielectric layer thus obtained are alternately laminated by a printing method, a transfer method, a green sheet method or the like. When a printing method is used, the dielectric layer paste and the internal electrode layer paste are laminated and printed on a substrate such as PET, cut into a predetermined shape, and then separated from the substrate to form a laminate. When a sheet method is used, a green sheet is formed using a dielectric layer paste, and an internal electrode layer paste is printed thereon, and then these are laminated to form a laminate.

Next, the thus obtained laminate is
After cutting to a predetermined laminate size, binder removal processing and firing are performed. Then, heat treatment is performed to re-oxidize the dielectric layer 2.

The binder removal treatment may be performed under ordinary conditions. When a base metal such as Ni or a Ni alloy is used as the conductor material of the internal electrode layer, it is particularly preferable to perform the treatment under the following conditions. Heating rate: 5 to 300 ° C / hour, especially 10 to 50 ° C / hour, Holding temperature: 200 to 400 ° C, especially 250 to 350 ° C, Holding time: 0.5 to 20 hours, especially 1 to 10 hours, atmosphere : In the air.

The firing conditions are preferably as follows. Heating rate: 50 to 500 ° C / hour, especially 200 to 300
° C / hour, holding temperature: 1000-1250 ° C, especially 1180-12
50 ° C., holding time: 0.5 to 8 hours, especially 1 to 3 hours, cooling rate: 50 to 500 ° C./hour, especially 200 to 300
° C / hour, atmosphere gas: humidified mixed gas of N ₂ and H ₂ , etc.

However, the oxygen partial pressure in the air atmosphere during firing
Is 10^-7atm or less, especially 10 ^-7-10^-13
It is preferable to perform atm. Beyond the range,
The internal electrode layer tends to oxidize, and the oxygen partial pressure increases.
If it is too low, the electrode material of the internal electrode layer will abnormally sinter.
This tends to be interrupted.

The heat treatment after firing is preferably performed at a holding temperature or a maximum temperature of 900 to 1100 ° C. If the holding temperature or the maximum temperature during the heat treatment is less than the above range, the life of the dielectric material tends to be short due to insufficient oxidation of the dielectric material, and if it exceeds the above range, Ni of the internal electrode is oxidized,
Not only does the capacity decrease, but it also reacts with the dielectric substrate, which tends to shorten its life. The oxygen partial pressure during the heat treatment is 10 ⁻⁸ atm or more, and more preferably 10 ⁻⁴ to 1
^0-7 atm is preferred. Below this range, reoxidation of the dielectric layer 2 is difficult, and beyond this range, the internal electrode layer 3 tends to oxidize. The other heat treatment conditions are preferably as follows.

Holding time: 0 to 6 hours, especially 2 to 5 hours, Cooling rate: 50 to 500 ° C./hour, especially 100 to 300
° C / hour, atmosphere gas: humidified N ₂ gas, etc.

In order to humidify the N ₂ gas or the mixed gas, for example, a wetter may be used. In this case, the water temperature is preferably about 0 to 75 ° C. Further, the binder removal treatment, the sintering, and the heat treatment may be performed continuously or independently. When these are continuously performed, after removing the binder, the atmosphere is changed without cooling, and then the temperature is raised to the holding temperature at the time of firing, firing is performed, and then the temperature is lowered to the holding temperature of the heat treatment. It is preferable to perform the heat treatment while changing the atmosphere. On the other hand, when performing these independently, at the time of firing was N ₂ gas or wet to the holding temperature of the binder removal process N ₂
After raising the temperature in a gas atmosphere, N ₂ that the temperature is preferably furthermore raised by changing the atmosphere, after cooling to the holding temperature at the time of annealing, which again N ₂ gas or wet
It is preferable to continue the cooling by changing to a gas atmosphere. Further, at the time of annealing, after raising the temperature to the holding temperature under N ₂ gas atmosphere, then change the atmosphere or a wet N ₂ gas atmosphere the entire process of annealing.

The sintered body thus obtained is subjected to end polishing by, for example, barrel polishing, sand plasting or the like.
The external electrode 4 is formed by baking the external electrode paste. The firing condition of the external electrode paste is preferably, for example, about 600 minutes to about 800 ° C. for about 10 minutes to about 1 hour in a humidified mixed gas of N ₂ and H ₂ . Then, a pad layer is formed by plating or the like on the external electrode 4 as necessary. Note that the external electrode paste may be prepared in the same manner as the internal electrode layer paste described above.

The multilayer ceramic capacitor of the present invention manufactured as described above is mounted on a printed circuit board or the like by soldering or the like, and is used for various electronic devices and the like.

It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention. For example, in the above embodiment, a multilayer ceramic capacitor was illustrated as an electronic device according to the present invention, but the electronic device according to the present invention is not limited to a multilayer ceramic capacitor, in _Yuden ceramic composition of the above composition Any material may be used as long as it has a configured dielectric layer.

[0069]

EXAMPLES Hereinafter, the present invention will be described based on more detailed examples, but the present invention is not limited to these examples.

Example 1 As a starting material, ΔB produced by sol-gel synthesis
_{a 0.91 Ca 0.0 089} O}} 0.990 (Ti
_0.80 Zr _0.20 ) A dielectric oxide having a composition represented by O ₂ was used. The average particle size of the dielectric oxide was 0.4 μm, and the maximum particle size was 1.5 μm.

Apart from the starting materials, a predetermined molar ratio of BaCO
₃, CaCO₃And SiO₂ In the ball mole
16 hours wet grinding, 1000-1200 ° C in air
Calcined, and calcined the product until the average particle size is 1 μm or less.
By grinding, (Ba_zCa_(1-z) ) S
iO₃Was obtained. BaCO₃, CaCO₃ And
And SiO₂By adjusting the molar ratio of
As shown in FIG._zCa
_(1-z) ) SiO₃Was obtained.

The thus obtained (Ba)_zCa
_(1-z) ) SiO₃Of the powder shown in Table 1
Is added to each starting material at the same time, and MnCO
₃, YO_0.5, VO_2.5And WO₃To
It was added and mixed in the molar ratio shown in Table 1 and mixed with a ball mill.
Time wet pulverization, titanium sample Nos. 3 to 16 shown in Table 1
A barium acid-based dielectric material was obtained. Also, (Ba_zC
a_(1-z) ) SiO ₃Did not add any powder
Otherwise, in the same manner as described above, sample numbers 1 and 2 shown in Table 1 were used.
And 2 barium titanate-based dielectric materials were obtained. Further
And (Ba_zCa_(1-z) ) SiO₃To powder
Change, SiO₂Same as above except that
The titanic acids of Sample Nos. 17 to 19 shown in Table 1 were prepared in the same manner.
A barium-based dielectric material was obtained. In Table 1,
A / B, x, indicating the composition ratio of the main components of the dielectric ceramic composition
y and the content of the subcomponent are obtained by firing the dielectric material.
Quantitative composition analysis of the obtained dielectric layer by X-ray fluorescence analysis
Determined from the results.

[0073]

[Table 1]

Each of the dielectric materials of Sample Nos. 1 to 19 was mixed in a ball mill using zirconia balls at the compounding ratio shown below, and slurried to obtain a dielectric layer paste. That is, a dielectric material: 100
5. parts by weight, acrylic resin: 5.0 parts by weight, benzyl butyl phthalate: 2.5 parts by weight, mineral spirit: 6.
5 parts by weight, acetone: 4.0 parts by weight, trichloroethane: 20.5 parts by weight, methylene chloride: 41.5 parts by weight.

Next, the mixture was kneaded with a three-roll mill at the mixing ratio shown below to form a slurry to obtain a paste for internal electrodes. That is, Ni is 44.6 parts by weight, terpineol is 52 parts by weight, ethyl cellulose is 3 parts by weight, and benzotriazole is 0.4 parts by weight. Using these pastes, the multilayer ceramic chip capacitor 1 shown in FIG. 1 was manufactured as follows.

First, a 16 μm-thick sheet was formed on a carrier film using a dielectric layer paste by a doctor blade method or the like, and an internal electrode was printed thereon using an internal electrode paste. Thereafter, the above-mentioned sheet was peeled off from the carrier film, and a plurality of sheets on which the internal electrodes were marked were laminated and pressure-bonded. Note that the number of stacked dielectric layers 2 was 10. Next, after the laminate was cut into a predetermined size, binder removal processing, firing and heat treatment were continuously performed under the following conditions.

Binder removal temperature rise rate: 20 ° C./hour, holding temperature: 250 ° C., holding time: 2 hours, atmosphere gas: air.

Firing temperature rise rate: 200 ° C./hour, holding temperature: temperature shown in Table 2, holding time: 2 hours, cooling temperature: 300 ° C./hour, atmosphere gas: humidified N ₂ and H ₂ Mixed gas, oxygen partial pressure: ^10-8 atm.

Heat treatment holding temperature: 1000 ° C., holding time: 3 hours, cooling temperature: 300 ° C./hour, atmosphere gas: humidified N ₂ gas, oxygen partial pressure: 10 ⁻⁷ atm.

The humidification of each atmosphere gas was performed at a water temperature of 0 to 75 ° C. using a wetter.

After the end face of the obtained sintered body was polished by sand blast, an In—Ga alloy was applied to form a test electrode. The size of the multilayer capacitor 1 manufactured in this way was 3.2 mm × 1.6 mm × 0.6 mm, the thickness of the dielectric layer 2 was 10 μm, and the thickness of the internal electrode 3 was 2 μm.

The characteristics of this multilayer capacitor were measured at a reference temperature of 25 ° C. using a digital LCR meter (YHP 4274A).
, A signal having a frequency of 1 KHz and a measurement voltage of 1.0 Vrms was input, and the capacitance and the dielectric loss tan δ were measured. The relative permittivity εr of the dielectric ceramic was calculated in consideration of the sample size and the capacitance of the dielectric ceramic of the multilayer capacitor.

The insulation resistance was measured by applying a DC voltage of 10 V to the multilayer capacitor for 1 minute. The breakdown voltage was increased at 3 V / S, and a voltage at which a current of 100 mA or more flowed was measured. As an evaluation, the relative permittivity εr is
This is an important characteristic for producing a small-sized capacitor having a high dielectric constant. The dielectric loss tan δ is an important characteristic for realizing a thinner dielectric layer 2 and producing a small and high-dielectric-constant capacitor, and is set to 15% or less, preferably 10% or less. An insulation resistance value of 1 × 10 ⁷ Ω or more was determined to be good. Breakdown voltage is 300V (20V / μm) or more,
Preferably, 450 V (30 V / μm) or more was determined to be good. These characteristic values are determined by the number of capacitor samples n =
It was determined from the average of the values measured using 10 samples. Table 2 shows the results.

[0084]

[Table 2]

In Tables 1 and 2, sample numbers corresponding to the examples of the present invention are marked with *. As can be seen by comparing Sample Nos. 1 and 2 corresponding to Comparative Examples and Sample Nos. 3 to 16 corresponding to Examples, by setting A / B to less than 1, firing at a low temperature can be performed. It was confirmed that the relative permittivity, dielectric loss, breakdown voltage and insulation resistance of the obtained dielectric layer were improved.

Further, Sample Nos. 17 to 1 corresponding to Comparative Examples
9, as can be seen by comparing the sample numbers 3-16 corresponding to _{Example, (Ba z Ca (1-} z)) SiO
It was confirmed that by performing the firing step after the addition of ₃ , firing at a low temperature was possible and the formation of a semiconductor could be prevented. The sample number 8 is the same as the sample number 7
But the firing temperature was too high,
It was confirmed that the composition turned into a semiconductor.

[0087]

As described above, according to the method for producing a dielectric porcelain composition of the present invention, the dielectric porcelain composition can be fired at a low temperature of 1250 ° C. or lower, and the resulting dielectric porcelain can be obtained. The relative dielectric constant, dielectric loss, breakdown voltage, and insulation resistance of the body layer are improved. Therefore, the electrical characteristics of electronic components such as a multilayer ceramic capacitor manufactured using the dielectric ceramic composition are improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Multilayer ceramic capacitor 10 ... Capacitor element body 2 ... Dielectric layer 3 ... Internal electrode layer 4 ... External electrode

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takako Hibi 1-13-1 Nihonbashi, Chuo-ku, Tokyo FTD term (reference) 4G031 AA04 AA05 AA06 AA07 AA11 AA12 AA13 AA17 AA18 AA19 AA24 AA26 AA30 AA31 AA33 AA39 BA09 CA03 GA11 5E001 AB03 AC03 AC09 AD03 AE00 AE02 AE03 AE04 AF06 AH01 AH05 AH06 AH08 AH09 AJ01 AJ02 5G303 AA01 AB01 AB06 AB07 AB15 AB20 BA07 BA12 CA01 CB03 CB30 CB CB CB CB CB CB CB CB CB CB CB CB CB CB CB CB CB CB CB CB CB CB CB CB CB DA06

Claims (6)

[Claims] 1. A _{{{Ba (1-x)} Ca x} O} A
_{(Ti (1-y) Zr} y) a step of preparing a main component containing a dielectric oxide of a composition represented by _{B O 2, Sr, Y,} Gd, Tb, Dy, V, Mo, Zn, Cd,
Oxides of Ti, Sn, W, Mn, Si and P and / or
Or a step of producing a sub-component containing at least one selected from compounds that become these oxides after firing, wherein the sub-component is, with respect to the entire composition, in terms of oxide,
Symbols A, B, x, and y indicating 0.001 to 5 mol% and indicating the composition ratio in the formula indicating the main component are: 0.990 ≦ A / B <1.000, 0.01 ≦ x ≦ 0.25, as a relationship of 0.1 ≦ y ≦ 0.3, the main component and / or auxiliary _{component, (Ba z Ca (1-} z))
A step of adding SiO ₃ (where Z = 0 to 1). To wherein said main component and / or secondary component, wherein the _{(Ba z Ca (1-z} )) SiO 3, the addition in an amount of 0.01 to 3% by weight of the total composition The method for producing a dielectric porcelain composition according to claim 1. 3. Ba_(1-x)Ca_x｝ O｝
_A(Ti_(1-y) Zr_y)_BO₂Indicated by
Producing a main component containing a dielectric oxide having a composition; and Sr, Y, Gd, Tb, Dy, V, Mo, Zn, Cd,
Oxides of Ti, Sn, W, Mn, Si and P and / or
Or selected from compounds that become these oxides after firing
A step of producing a sub-component containing at least one type, wherein the sub-component is, with respect to the entire composition, in terms of oxide,
0.001 to 5 mol%, in the formula showing the main component
The symbols A, B, x, and y indicating the composition ratios have a relationship of 0.990 ≦ A / B <1.000, 0.01 ≦ x ≦ 0.25, and 0.1 ≦ y ≦ 0.3. In addition, the main component
And / or (Ba)_zCa_(1-z) )
SiO₃(Where Z = 0 to 1), and using a powder obtained by mixing the main component and the subcomponent.
Forming a dielectric paste, and preparing an internal electrode paste, alternately using the dielectric paste and the internal electrode paste.
A method for producing an electronic component, comprising: a step of obtaining a laminate by laminating; and a step of firing the laminate.
Law. To wherein said main component and / or secondary component, wherein the _{(Ba z Ca (1-z} )) SiO 3, the addition in an amount of 0.01 to 3% by weight of the total composition The method for manufacturing an electronic component according to claim 3, wherein: 5. The method according to claim 3, wherein the laminate is fired at a temperature of 1250 ° C. or less. 6. The method for manufacturing an electronic component according to claim 3, wherein nickel or a nickel alloy is used as the internal electrode paste.