JP2007258475A - Laminated electronic component and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated electronic component which can be baked in a reductive atmosphere, has excellent DC bias characteristics, has decreased electrostriction quantity, has capacitive temperature characteristics satisfying X6S characteristics of EIA standards, and further, is excellent in high-temperature acceleration lifetime, and to provide a manufacturing method thereof. <P>SOLUTION: The laminated electronic component has a configuration of alternately laminating a dielectric layer consisting of a dielectric porcelain composition in which BaTiO<SB>3</SB>, SrTiO<SB>3</SB>and CaTiO<SB>3</SB>are included as main components, these BaTiO<SB>3</SB>, SrTiO<SB>3</SB>and CaTiO<SB>3</SB>do not substantially form a solid solution with each other but form a composite structure; and an internal electrode layer. In the manufacturing method of the laminated electronic component, an electrode paste containing a conductive powder, and a co-material containing a BaTiO<SB>3</SB>powder, an SrTiO<SB>3</SB>powder and a CaTiO<SB>3</SB>powder is used as an electrode paste for forming an electrode paste film to be used as an internal electrode after baking. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multilayer electronic component such as a multilayer ceramic capacitor and a manufacturing method thereof.

  Multilayer ceramic capacitors are widely used as small-sized, large-capacity, high-reliability electronic components, and the number used in electrical and electronic devices is large. In recent years, with the miniaturization and high performance of devices, the demand for further miniaturization, larger capacity, lower cost, and higher reliability of multilayer ceramic capacitors has become increasingly severe.

  At present, ferroelectric ceramic materials are generally used for small-sized and high-capacity ceramic capacitors. Such a ferroelectric ceramic material is accompanied by an electrostriction phenomenon in which mechanical distortion occurs when an electric field is applied. Therefore, when a voltage is applied to a ceramic capacitor using a ferroelectric ceramic material, the electrostriction phenomenon occurs. Vibration due to.

  In particular, such an electrostriction phenomenon can cause vibration of not only the capacitor itself but also the board and surrounding components when a ceramic capacitor is mounted on a circuit board. May emit a vibration sound having an audible frequency (20 to 20000 Hz). This vibration sound may be in a range that is uncomfortable for humans, and countermeasures have been required.

  On the other hand, for example, in Patent Document 1, in order to suppress the transmission of the vibration of the ceramic capacitor due to the electrostriction phenomenon to the substrate, the ceramic capacitor is provided with an electrode connection portion for connecting the external terminal electrode and the substrate, It has been proposed to provide a certain separation distance between the lower surface of the capacitor element body and the substrate.

  However, as described in this document, if a method of providing a certain separation distance by the electrode connecting portion is adopted, the manufacturing cost of the ceramic capacitor increases, and the height direction of the capacitor increases, resulting in a small size. Further improvement has been desired in view of the difficulty in making it easier.

  Patent Document 2 contains calcium titanate, strontium titanate, and barium titanate, and the compositional molar ratio of at least barium titanate is 0.3 or less with respect to these three compositional molar ratios. A dielectric ceramic composition comprising at least one crystal structure of a tetragonal crystal is disclosed. The dielectric ceramic composition described in this document is particularly intended to reduce third harmonic distortion (THD). However, the dielectric ceramic composition of this document is not sufficient for improving the above-described electrostriction phenomenon, and has a structure in which the main components calcium titanate, strontium titanate and barium titanate are dissolved in each other. Since it is employed, the capacity-temperature characteristic is not sufficient, and for example, the X6S characteristic of the EIA standard (−55 to 105 ° C., ΔC / C = within ± 22%) cannot be satisfied.

  In general, a multilayer ceramic capacitor having the above-described configuration is generally formed by printing an electrode paste for forming an internal electrode in a predetermined pattern on a ceramic green sheet mainly composed of ceramic powder and a binder, and then simultaneously firing them. Then, it is integrally sintered, and finally an external electrode is formed. As the conductive material for the internal electrode, Pd or Pd alloy is used. However, since Pd is expensive, a relatively inexpensive base metal such as Ni or Ni alloy has been used. However, base metals such as Ni and Ni alloys have the property of being sintered at a lower temperature than the dielectric powder constituting the dielectric layer. Therefore, for example, as in Patent Documents 3 and 4, in order to bring the sintering behavior of the internal electrode layer closer to the sintering behavior of the dielectric layer, ceramic powder as a co-material is used as an electrode paste for forming the internal electrode. A method of adding is known.

JP 2004-335963 A JP 2000-264729 A JP 2003-68559 A JP 2005-101318 A

  The object of the present invention is that firing in a reducing atmosphere is possible, the relative dielectric constant and DC bias characteristics (dependence of the dielectric constant on the DC voltage application) are good, and the amount of electrostriction during voltage application is reduced. Provided is a multilayer electronic component that can satisfy the EIA standard X6S characteristic (−55 to 105 ° C., ΔC / C = ± 22% or less) and has a high temperature accelerated life and a method for manufacturing the same. With the goal.

As a result of intensive studies to achieve the above object, the present inventors have made BaTiO ₃ , SrTiO _3, and CaTiO ₃ as main components of a dielectric layer constituting a multilayer electronic component such as a multilayer ceramic capacitor. And an electrode paste film that is composed of a dielectric ceramic composition that is substantially insoluble in each other and forms a composite structure, and that serves as an internal electrode layer after firing, a conductor powder, and BaTiO It was found that the above-mentioned object can be achieved by forming an electrode paste containing ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder, and the present invention has been completed.

That is, the method for manufacturing a multilayer electronic component according to the present invention includes:
A method of manufacturing a multilayer electronic component having a configuration in which dielectric layers and internal electrode layers are alternately laminated,
Forming a green sheet to be a dielectric layer after firing;
Using an electrode paste to form an electrode paste film that becomes an internal electrode layer after firing;
Alternately stacking the green sheet and the electrode paste film to obtain a green chip;
Firing the green chip,
The dielectric layer after firing contains BaTiO ₃ , SrTiO ₃ and CaTiO ₃ as main components, and the BaTiO ₃ , SrTiO ₃ and CaTiO ₃ are not substantially dissolved in each other, and composite Consisting of a dielectric porcelain composition forming the structure,
As the electrode paste for forming the electrode paste film, an electrode paste containing a conductor powder and a co-material containing BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder is used.

In the present invention, preferably, the content ratio of the BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder in the electrode paste is expressed by the formula {(Ba _α , Sr _β , Ca _γ ) O} _n TiO ₂ . The symbols α, β, γ and n in the above formula are
0.1 ≦ α ≦ 0.7,
0.1 ≦ β ≦ 0.7,
0.1 ≦ γ ≦ 0.7,
α + β + γ = 1,
0.8 ≦ n ≦ 1.3,
It is.

In the present invention, preferably, the dielectric ceramic composition, said BaTiO _3, SrTiO ₃ and CaTiO compositional molar ratio of ₃ to be contained as the main component, a composition formula _{{(Ba x Sr y Ca z} ) O} m In the case of TiO ₂ , the symbols x, y, z and m in the above formula are
0.19 ≦ x ≦ 0.23,
0.25 ≦ y ≦ 0.31,
0.46 ≦ z ≦ 0.54,
x + y + z = 1,
0.980 ≦ m ≦ 1.01,
It is.

Alternatively, in the present invention, preferably, the composition molar ratio of BaTiO ₃ , SrTiO ₃ and CaTiO ₃ contained as main components in the dielectric ceramic composition is expressed by a composition formula {(Ba _x Sr _y Ca _z ) O. } _m TiO ₂ (provided that in the above formulas, x + y + z = 1 ) in the case shown in,
The relationship between α which is the ratio of the BaTiO ₃ powder in the electrode paste and x which is the ratio of the BaTiO ₃ in the dielectric ceramic composition is α ≦ x,
More preferably, the composition formula _{{(Ba x Sr y Ca z} ) O} m TiO 2 symbols x, y, z and m,
0.19 ≦ x ≦ 0.23,
0.25 ≦ y ≦ 0.31,
0.46 ≦ z ≦ 0.54,
0.980 ≦ m ≦ 1.01,
It is.

In the present invention, preferably, the common material constituting the electrode paste is,
A compound of Mn;
A compound of Si;
One or more selected from compounds of each element of V, Ta, Nb, W, Mo and Cr,
For a total of 100 moles of BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder,
The content of the Mn compound is 0.3 to 1 mol in terms of MnO,
The content of the Si compound is 0.1 to 0.5 mol in terms of SiO ₂ ,
Content of the compound of said V, Ta, Nb, W, Mo, and Cr is 0.02 mol or more and less than 0.40 mol in conversion of each element of V, Ta, Nb, W, Mo, and Cr.

  In this invention, Preferably, content of the said common material in the said electrode paste is 1-30 weight part with respect to 100 weight part of said conductor powders.

The multilayer electronic component according to the present invention is manufactured by any one of the above methods,
Dielectric porcelain containing BaTiO ₃ , SrTiO ₃ and CaTiO ₃ as main components, and the BaTiO ₃ , SrTiO ₃ and CaTiO ₃ are not substantially dissolved in each other to form a composite structure. A dielectric layer including the composition; and an internal electrode layer.

  Preferably, the dielectric crystal constituting the dielectric layer has an average crystal particle diameter of 0.2 to 2 μm.

  Preferably, the dielectric layer has a thickness of 2 to 20 μm. By setting the thickness of the dielectric layer in such a range, it can be used for medium withstand voltage applications having a high rated voltage (for example, 100 V or more).

  The multilayer electronic component according to the present invention is not particularly limited, and examples thereof include multilayer ceramic capacitors, piezoelectric elements, chip inductors, chip varistors, chip thermistors, chip resistors, and other surface mount (SMD) chip electronic components. .

According to the present invention, the dielectric ceramic includes a dielectric layer containing BaTiO ₃ , SrTiO _3, and CaTiO ₃ as main components, and these are not substantially dissolved in each other to form a composite structure. It is composed of a composition. Therefore, the dielectric constant is high, the DC bias characteristic is good, the capacitance temperature characteristic can be improved while reducing the amount of electrostriction when a voltage is applied, and in particular, the X6S characteristic of the EIA standard can be satisfied.

Moreover, in the present invention, in addition to the dielectric layer and the composite structure comprising BaTiO _3, SrTiO ₃ and CaTiO _3, with BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ electrode paste containing a powder as a common material The internal electrode layer is formed. Therefore, it is possible to improve the high temperature load life while maintaining the above characteristics.

For example, in the above-mentioned Patent Document 3 (Japanese Patent Laid-Open No. 2003-68559), a composite composed of BCT type crystal particles containing Ba, Ca and Ti and BT type crystal particles containing Ba and Ti. In a multilayer ceramic capacitor having a dielectric layer forming a structure, a method is disclosed in which an internal electrode is formed using an electrode paste containing (Ba, Ca) TiO ₃ crystal powder as a co-material. However, in this Patent Document 3, while the crystal particles constituting the dielectric layer have a composite structure, crystal particles having a uniform dielectric composition are used as a material to be included as a co-material. Therefore, in this patent document 3, the improvement effect of a high temperature load lifetime cannot be acquired like this invention.

Further, in Patent Document 4 (Japanese Patent Laid-Open No. 2005-101318) described above, from crystal grains in which Ba and Ca as A site components and Ti and Zr as B site components are dissolved as main components, respectively. In a multilayer ceramic capacitor having a dielectric layer configured, a method of forming an internal electrode using an electrode paste containing BaTiO ₃ powder, BaZrO ₃ powder and CaZrO ₃ powder as a co-material is disclosed. However, in this Patent Document 4, while BaTiO ₃ powder, BaZrO ₃ powder and CaZrO ₃ powder are used as co-materials to be included in the electrode paste, the crystal particles constituting the dielectric layer are not a composite structure but a solid solution. It is formed with. For this reason, even in Patent Document 4, the effect of improving the high temperature load life cannot be obtained as in the present invention.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a cross-sectional view of a multilayer ceramic capacitor according to an embodiment of the present invention.

Multilayer ceramic capacitor 1
As shown in FIG. 1, a multilayer ceramic capacitor 1 according to an embodiment of the present invention includes a capacitor element body 10 having a configuration in which dielectric layers 2 and internal electrode layers 3 are alternately stacked. 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 arranged alternately in the element body 10. The shape of the capacitor element body 10 is not particularly limited, but is usually a rectangular parallelepiped shape. Moreover, there is no restriction | limiting in particular also in the dimension, What is necessary is just to set it as a suitable dimension according to a use.

  The internal electrode layers 3 are laminated so that the end faces are alternately exposed on the surfaces of the two opposite 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 are connected to the exposed end surfaces of the alternately arranged internal electrode layers 3 to constitute a capacitor circuit.

Dielectric layer 2
The dielectric layer 2 contains a dielectric ceramic composition.
The dielectric ceramic composition contained in the dielectric layer 2 has a main component including BaTiO ₃ , SrTiO ₃ and CaTiO ₃ .

In the present embodiment, the BaTiO ₃ , SrTiO ₃ and CaTiO ₃ constituting the main component are contained in a state where they are not substantially dissolved in each other. That is, in this embodiment, these BaTiO ₃ , SrTiO ₃ and CaTiO ₃ are contained as BaTiO ₃ crystal particles, SrTiO ₃ crystal particles and CaTiO ₃ crystal particles as separate crystal particles, respectively, and form a composite structure. .

However, BaTiO ₃ , SrTiO ₃ and CaTiO ₃ may be substantially contained as BaTiO ₃ crystal particles, SrTiO ₃ crystal particles and CaTiO ₃ crystal particles. For example, BaTiO ₃ crystal particles and SrTiO ₃ crystal particles In the vicinity of the interface, a part of the solid solution phase may be formed.

By making BaTiO ₃ , SrTiO _3, and CaTiO ₃ into a state where they are not substantially dissolved in each other and forming a composite structure, it is possible to improve the capacity-temperature characteristics while maintaining a high dielectric constant. In particular, the X6S characteristic of the EIA standard (−55 to 105 ° C., ΔC / C = within ± 22%) can be satisfied. The reason for this is considered to be, for example, that the Curie temperature peak derived from BaTiO ₃ remains due to the non-solid solution and the composite structure.

Whether or not BaTiO ₃ , SrTiO ₃ and CaTiO ₃ constituting the main component are dissolved in each other can be confirmed by, for example, X-ray diffraction of the dielectric layer 2. Specifically, the dielectric layer 2 is subjected to X-ray diffraction using Cu-Kα ray as an X-ray source, and BaTiO ₃ , SrTiO ₃ and CaTiO ₃ are respectively obtained in the range of 2θ = 30 to 35 °. This can be confirmed by whether or not the resulting separable three diffraction peaks are observed. The diffraction peaks observed in the range of 2θ = 30 to 35 ° are the diffraction peak of the (110) plane of BaTiO ₃ , the diffraction peak of the (110) plane of SrTiO ₃ , and the (121) plane of CaTiO ₃ , respectively. It is a diffraction peak.

Further, when there is no particular limitation on the composition molar ratio of BaTiO _3, SrTiO ₃ and CaTiO ₃ that constitute the main component, showing them by a composition formula _{{(Ba x Sr y Ca z} ) O} m TiO 2, The symbols x, y, z and m in the above formula are preferably
0.19 ≦ x ≦ 0.23,
0.25 ≦ y ≦ 0.31,
0.46 ≦ z ≦ 0.54,
0.980 ≦ m ≦ 1.01,
And more preferably
0.195 ≦ x ≦ 0.225,
0.255 ≦ y ≦ 0.305,
0.465 ≦ z ≦ 0.535,
0.985 ≦ m ≦ 1.075,
It is. In the above formula, x + y + z = 1.
By making the symbols x, y, z, and m within the above ranges, it is possible to enhance the effect of improving DC bias characteristics and the effect of reducing the amount of electrostriction during voltage application. In the above composition formula, the amount of oxygen (O) may be slightly deviated from the stoichiometric composition of the above formula.

In the above formula, x represents the content ratio of BaTiO ₃ . As the content of BaTiO _{3 in} the main component increases, the ferroelectricity tends to increase. If x is too small, the relative permittivity tends to be low. In particular, if the relative dielectric constant is too low, it is necessary to increase the number of laminated dielectric layers 2 in order to obtain a desired capacitance. Therefore, there arises a problem that it becomes difficult to reduce the size. On the other hand, if x is too large, although the relative permittivity is improved, the amount of electrostriction when a voltage is applied increases, and the DC bias characteristics tend to deteriorate.

In the above formula, y represents the content ratio of SrTiO ₃ . When the content of SrTiO _{3 in} the main component increases, the paraelectric property tends to increase. If y is too small, the dielectric constant tends to be low. On the other hand, if y is too large, the DC bias characteristics tend to deteriorate.

In the above formula, z indicates the content of CaTiO _3. CaTiO ₃ is mainly effect and of improving the sintering stability has the effect of improving the insulation resistance value. If z is too small, the DC bias characteristics tend to deteriorate. On the other hand, if z is too large, the dielectric constant tends to decrease.

When the content of BaTiO _{3 in} the main component increases, the ferroelectricity becomes stronger. On the other hand, when the content of SrTiO ₃ and CaTiO ₃ in the main component increases, the paraelectric property tends to increase, and the symbol x By setting, y, and z within the above ranges, a balance between the ferroelectric phase and the paraelectric phase can be achieved.

  In the above formula, m represents the ratio of the A site of the perovskite structure to the B site (ratio of Ba, Sr and Ca and Ti). By setting m to 0.980 or more, the grain growth of dielectric particles during firing can be suppressed, and the dielectric particles constituting the dielectric layer after firing can be miniaturized. Further, by setting m to 1.01 or less, a dense sintered body can be obtained without increasing the firing temperature. If m is too small, it is difficult to make the dielectric particles fine, and the DC bias characteristics tend to deteriorate. On the other hand, if m is too large, the sintering temperature becomes too high and sintering tends to be difficult.

The dielectric ceramic composition preferably further contains a subcomponent in addition to the main component described above.
In the present embodiment, as subcomponents, an oxide of Mn, an oxide of Si, and at least one selected from oxides of elements of V, Ta, Nb, W, Mo, and Cr are further included. It is preferable to contain.

  The oxide of Mn has the effect of promoting sintering and the effect of improving the high temperature load life. The content of the Mn oxide is preferably 0.3 to 1 mol and more preferably 0.3 to 0.8 mol in terms of MnO with respect to 100 mol of the main component. If the content of the Mn oxide is too small, the sinterability deteriorates and the high temperature load life tends to be inferior. On the other hand, if the content is too large, the IR defect rate may deteriorate.

The Si oxide mainly acts as a sintering aid, but has an effect of improving the defective rate of the initial insulation resistance when the layer is thinned. The content of the Si oxide is preferably 0.1 to 0.5 mol and more preferably 0.15 to 0.45 mol in terms of SiO _{2 with} respect to 100 mol of the main component. If the content of Si oxide is too small, the firing temperature may increase. On the other hand, when the amount is too large, the IR defect rate tends to deteriorate.

In the present embodiment, Si oxide may be included in the form of a complex oxide. Examples of such composite oxides include composite oxides of SiO ₂ and oxides of elements constituting other main components and subcomponents contained in the dielectric ceramic composition. For example, CaSiO ₃ , SrSiO ₃ , (Ca, Sr) SiO ₃ , MnSiO ₃ , BaSiO _{3 and the} like. When these composite oxides are used, they may be appropriately adjusted so that the composition after firing falls within a desired range.

The oxides of each element of V, Ta, Nb, W, Mo, and Cr have an effect of improving the high temperature load life. The content of these oxides is preferably 0.02 mol or more and less than 0.40 mol in terms of each oxide of V, Ta, Nb, W, Mo and Cr with respect to 100 mol of the main component. More preferably, it is 0.03-0.30 mol, More preferably, it is 0.05-0.20 mol. If the content of these oxides is too small, the above effect is difficult to obtain. On the other hand, if too much, IR tends to decrease.
In addition, the said content is content of each element conversion, for example, in the oxide of V, when content in V element conversion is 0.10 mol, it is V ₂ O ₅ which is the oxide The content in terms of conversion is 0.05 mol.

  Moreover, in this embodiment, you may contain subcomponents other than the above as needed. Such subcomponents are not particularly limited. For example, Ba, Ca, Sr, Li, Mg, Al, Zr, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb , Dy, Ho, Er, Tm, Yb, and Lu oxides.

  Although the thickness of the dielectric material layer 2 is not specifically limited, Preferably it is 2-20 micrometers. By setting the thickness of the dielectric layer 2 in such a range, it is possible to correspond to a medium withstand voltage application having a high rated voltage (for example, 100 V or more). If the dielectric layer 2 is too thin, the short-circuit defect rate may deteriorate. On the other hand, if it is too thick, it is difficult to reduce the size of the capacitor.

Internal electrode layer 3
The internal electrode layer 3 is formed using an electrode paste described later.
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, Cu, Ni alloy or Cu alloy is preferable, and Ni or Ni alloy is particularly preferable. When the main component of the internal electrode layer 3 is Ni or a Ni alloy, it is preferable to fire at a low oxygen partial pressure (reducing atmosphere) so that the dielectric is not reduced. The thickness of the internal electrode layer 3 is preferably 0.5 to 2 μm, more preferably 0.8 to 1.5 μm.

External electrode 4
The conductive material contained in the external electrode 4 is not particularly limited, but in the present invention, inexpensive Ni, Cu, and alloys thereof can be used. What is necessary is just to determine the thickness of the external electrode 4 suitably according to a use etc.

Manufacturing Method of Multilayer Ceramic Capacitor 1 The multilayer ceramic capacitor 1 of the present embodiment is the same as a conventional multilayer ceramic capacitor. After producing a green chip by a normal printing method or a sheet method using a paste and firing it, It is manufactured by printing or transferring an external electrode and baking. Hereinafter, the manufacturing method will be specifically described.

Preparation of Dielectric Paste First, a dielectric material (dielectric ceramic composition powder) contained in the dielectric paste is prepared, and this is made into a paint to prepare a dielectric paste.

  The dielectric paste may be an organic paint obtained by kneading a dielectric material and an organic vehicle, or may be a water-based paint.

  As the dielectric material, the above-mentioned main component and subcomponent oxides, mixtures thereof, and composite oxides can be used. In addition, various compounds that become the above oxides or composite oxides by firing, such as carbonic acid, can be used. A salt, an oxalate salt, a nitrate salt, a hydroxide, an organometallic compound, or the like can be selected as appropriate and used in combination. What is necessary is just to determine content of each compound in a dielectric raw material so that it may become a composition of the above-mentioned dielectric ceramic composition after baking. In the state before forming a paint, the particle size of the dielectric material is usually about 0.1 to 1 μm in average particle size.

In the present embodiment, as a material of the main component, BaTiO ₃ powder, it is preferable to use SrTiO ₃ powder and CaTiO ₃ powder, in particular, those BaTiO ₃ powder, SrTiO ₃ powder, CaTiO ₃ powder, pre-reacted with each other It is preferable to use without making it. BaTiO ₃ , SrTiO _3, and SrTiO ₃ that constitute the main component in the sintered dielectric ceramic composition by using these powders as raw materials of the main component and using them without reacting with each other in advance. the CaTiO _3, each other, can be configured to not substantially dissolved. That is, in the sintered dielectric ceramic composition, these composite oxides can be present in the form of BaTiO ₃ crystal particles, SrTiO ₃ crystal particles, and CaTiO ₃ crystal particles to form a composite structure.

In addition to the powders described above, the raw material for the main component is TiO in order to adjust the ratio between the A site and B site of the perovskite structure (ratio of Ba, Sr and Ca and Ti). ₂ may be further added.

  In addition, as raw materials other than the main components (for example, raw materials for subcomponents), each oxide or a compound that becomes each oxide by firing may be used as it is, or calcined and roasted in advance. It may be used as

  An organic vehicle is obtained by dissolving a binder in an organic solvent. The binder used for the organic vehicle is not particularly limited, and may be appropriately selected from normal various binders such as butyral resins such as ethyl cellulose and polyvinyl butyral, and acrylic resins. Moreover, the organic solvent to be used is not particularly limited, and may be appropriately selected from various organic solvents such as terpineol, butyl carbitol, acetone, toluene, ethanol, and xylene according to a method to be used such as a printing method or a sheet method.

  Further, when the dielectric paste is used as a water-based paint, a water-based vehicle in which a water-soluble binder or a dispersant is dissolved in water and a dielectric material may be kneaded. The water-soluble binder used for the water-based vehicle is not particularly limited, and for example, polyvinyl alcohol, cellulose, water-soluble acrylic resin, etc. may be used.

Preparation of electrode paste Next, an electrode paste is prepared to form the internal electrode layer 3 shown in FIG. 1 after firing.
As an electrode paste for forming the internal electrode layer 3, a paste containing a conductor powder, a common material, and an organic vehicle is used.

  Although it does not specifically limit as conductor powder, It is preferable to comprise by at least 1 sort (s) chosen from Cu, Ni, and these alloys, More preferably, it comprises Ni or Ni alloy.

  Ni or an Ni alloy is preferably an alloy of Ni and at least one element selected from Mn, Cr, Co, and Al, and the Ni content in the alloy is preferably 95% by weight or more. In addition, in Ni or Ni alloy, various trace components, such as P, Fe, and Mg, may be contained about 0.1 wt% or less.

In the present embodiment, BaTiO ₃ powder, SrTiO ₃ powder, and CaTiO ₃ powder are used as the common material.
The proportions of BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder as co-materials are expressed by the symbol α in the formula when these are represented by the formula {(Ba _α , Sr _β , Ca _γ ) O} _n TiO ₂ , β, γ and n are preferably
0.1 ≦ α ≦ 0.7,
0.1 ≦ β ≦ 0.7,
0.1 ≦ γ ≦ 0.7,
0.8 ≦ n ≦ 1.3,
More preferably,
0.15 ≦ α ≦ 0.5,
0.15 ≦ β ≦ 0.5,
0.2 ≦ γ ≦ 0.65,
0.9 ≦ n ≦ 1.2,
Prepare so that In the above formula, α + β + γ = 1.

By using BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder as a co-material to be included in the electrode paste, while maintaining good dielectric constant, DC bias characteristics, electrostriction amount and capacity-temperature characteristics at the time of voltage application, High temperature accelerated life can be improved. In particular, by setting the content ratio of each powder within the above range, it is possible to effectively prevent the compositional deviation of the dielectric layer 2 from occurring when these powders diffuse from the internal electrode to the dielectric layer 2 during firing. be able to. Therefore, the effect of improving the high temperature accelerated life can be exhibited without causing deterioration of characteristics.

In the above formula, α represents the content ratio of the BaTiO ₃ powder. If α is too small, the dielectric constant tends to decrease. On the other hand, if α is too large, the high temperature accelerated life tends to deteriorate.
In the above formula, β represents the content ratio of the SrTiO ₃ powder. If β is too small or too large, the capacity-temperature characteristic tends to deteriorate and the X6S characteristic tends not to be satisfied.
In the above formula, gamma indicates the content of CaTiO ₃ powder. If γ is too small or too large, the capacity-temperature characteristic tends to deteriorate, and the X6S characteristic tends not to be satisfied.
In the above formula, n represents the ratio of the A site and B site of the perovskite structure (ratio of Ba, Sr and Ca and Ti). If n is too small, the high temperature accelerated life tends to deteriorate. On the other hand, if n is too large, the sinterability will deteriorate.

In the present embodiment, in addition to making the content ratio of each powder in the electrode paste have the above relationship, the content ratio of the BaTiO ₃ powder in the electrode paste is set in the dielectric ceramic composition constituting the dielectric layer 2. It is preferable to have the following relationship with respect to the content ratio of BaTiO ₃ in.
Specifically, when the composition molar ratio of the main component of the dielectric ceramic composition constituting the dielectric layer 2, expressed by a composition formula _{{(Ba x Sr y Ca z} ) O} m TiO 2, electrode The symbol α indicating the content ratio of the BaTiO ₃ powder in the paste preferably has a relationship of α ≦ x with respect to the symbol x indicating the content ratio of BaTiO ₃ in the dielectric layer 2. That is, it is preferable that the content ratio of BaTiO ₃ powder in the electrode paste is the same as or less than the content ratio of BaTiO ₃ in the dielectric ceramic composition constituting the dielectric layer 2. Such a relationship makes it possible to further improve the high temperature accelerated life.

  In addition, the common material contained in the electrode paste includes, as an additive component, at least one selected from a compound of Mn, a compound of Si, and a compound of each element of V, Ta, Nb, W, Mo, and Cr And may further be included. By containing these additive components, the high temperature accelerated life can be further improved. In addition to the oxides of the above elements, such additive components include compounds that become oxides upon firing (for example, carbonates, oxalates, nitrates, hydroxides, organometallic compounds, etc.). Can be mentioned. These additive components may be preliminarily calcined and used as roasted powder.

The content ratio of each additive component is preferably in the following range with respect to a total of 100 moles of BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder.
That is, the content of the Mn compound is preferably 0.3 to 1 mol, more preferably 0.3 to 0.8 mol in terms of MnO. The content of the Si compound is 0.1 to 0.5 mol, more preferably 0.15 to 0.45 mol in terms of SiO ₂ . The content of the compounds of V, Ta, Nb, W, Mo and Cr is preferably 0.02 mol or more and less than 0.40 mol in terms of each element of V, Ta, Nb, W, Mo and Cr. More preferably, it is 0.03-0.30 mol.

  The content of the common material in the electrode paste is preferably 1 to 30 parts by weight, more preferably 5 to 25 parts by weight with respect to 100 parts by weight of the conductor powder. If the content of the co-material is too small, the difference in shrinkage behavior between the internal electrode layer and the dielectric layer during firing becomes large, and structural defects such as cracks are likely to occur. On the other hand, when there is too much content of a common material, a capacity temperature characteristic and a high temperature accelerated lifetime will deteriorate.

  As the organic vehicle, the same one as the above-described dielectric paste may be used.

  The electrode paste can be formed by mixing the above-described components with a ball mill, a three-roll mill, or the like to form a slurry. Or you may employ | adopt the method of adding the co-material which has the said structure to a commercially available electrode paste.

Preparation of Green Chip, baking, etc. Then, by using the dielectric paste prepared in the above, by a doctor blade method, on a carrier sheet, to form a ceramic green sheet. The ceramic green sheet becomes the dielectric layer 2 shown in FIG. 1 after firing.

  As the carrier sheet, for example, a PET film or the like is used, and a film coated with silicone or the like is preferable in order to improve peelability. Although the thickness of a carrier sheet is not specifically limited, Preferably it is 5-100 micrometers.

  A predetermined pattern of electrode paste film (internal electrode pattern) that becomes the internal electrode layer 3 shown in FIG. 1 after firing on the surface of the ceramic green sheet formed on the carrier sheet using the electrode paste prepared above. Form.

  The method for forming the electrode paste film is not particularly limited as long as it is a method capable of forming a layer uniformly, and examples thereof include a screen printing method.

Next, a plurality of ceramic green sheets having a predetermined pattern of electrode paste film formed on the surface are stacked to produce a green chip.
Then, before the firing, the green chip is subjected to binder removal processing. As binder removal conditions, the temperature rising rate is preferably 5 to 300 ° C./hour, the holding temperature is preferably 180 to 400 ° C., and the temperature holding time is preferably 0.5 to 24 hours. The firing atmosphere is air or a reducing atmosphere.

The atmosphere at the time of green chip firing may be appropriately determined according to the type of conductive material in the internal electrode layer paste, but when a base metal such as Ni or Ni alloy is used as the conductive material, the oxygen content in the firing atmosphere The pressure is preferably 10 ⁻¹⁰ to 10 ⁻³ Pa. When the oxygen partial pressure is less than the above range, the conductive material of the internal electrode layer may be abnormally sintered and may be interrupted. Further, when the oxygen partial pressure exceeds the above range, the internal electrode layer tends to be oxidized.

  Moreover, the holding temperature at the time of baking becomes like this. Preferably it is 1000-1400 degreeC, More preferably, it is 1100-1360 degreeC. If the holding temperature is lower than the above range, the densification becomes insufficient. If the holding temperature is higher than the above range, the electrode is interrupted due to abnormal sintering of the internal electrode layer, the capacity temperature characteristic is deteriorated due to diffusion of the constituent material of the internal electrode layer, and the dielectric Reduction of the body porcelain composition is likely to occur.

As other firing conditions, the rate of temperature rise is preferably 50 to 500 ° C./hour, more preferably 200 to 300 ° C./hour, and the temperature holding time is preferably 0.5 to 8 hours, more preferably 1 to 3 hours. The time and cooling rate are preferably 50 to 500 ° C./hour, more preferably 200 to 300 ° C./hour. Further, the firing atmosphere is preferably a reducing atmosphere, and as the atmosphere gas, for example, a mixed gas of N ₂ and H ₂ can be used by humidification.

  When firing in a reducing atmosphere, it is preferable to anneal the capacitor element body. Annealing is a process for re-oxidizing the dielectric layer, and this can significantly increase the IR lifetime, thereby improving the reliability.

The oxygen partial pressure in the annealing atmosphere is preferably 10 ^{−1 to} 10 Pa. When the oxygen partial pressure is less than the above range, it is difficult to re-oxidize the dielectric layer, and when it exceeds the above range, oxidation of the internal electrode layer tends to proceed.

  The holding temperature at the time of annealing is preferably 1100 ° C. or less, particularly 500 to 1100 ° C. When the holding temperature is lower than the above range, the dielectric layer is not sufficiently oxidized, so that the IR is low and the high temperature load life is likely to be shortened. On the other hand, when the holding temperature exceeds the above range, not only the internal electrode layer is oxidized and the capacity is lowered, but the internal electrode layer reacts with the dielectric substrate, the capacity temperature characteristic is deteriorated, the IR is lowered, and the high temperature is increased. The load life is likely to decrease. Note that annealing may be composed of only a temperature raising process and a temperature lowering process. That is, the temperature holding time may be zero. In this case, the holding temperature is synonymous with the maximum temperature.

As other annealing conditions, the temperature holding time is preferably 0 to 20 hours, more preferably 2 to 10 hours, and the cooling rate is preferably 50 to 500 ° C./hour, more preferably 100 to 300 ° C./hour. . Further, as the annealing atmosphere gas, for example, humidified N ₂ gas or the like is preferably used.

In the above-described binder removal processing, firing and annealing, for example, a wetter or the like may be used to wet the N ₂ gas or mixed gas. In this case, the water temperature is preferably about 5 to 75 ° C.
The binder removal treatment, firing and annealing may be performed continuously or independently.

The capacitor element main body obtained as described above is subjected to end face polishing, for example, by barrel polishing or sand blasting, and the external electrode paste is applied and fired to form the external electrode 4. Then, if necessary, a coating layer is formed on the surface of the external electrode 4 by plating or the like.
The multilayer ceramic capacitor of this embodiment manufactured in this way is mounted on a printed circuit board or the like by soldering or the like and used for various electronic devices.

  According to the present embodiment, the dielectric layer 2 of the multilayer ceramic capacitor is composed of the above-described dielectric ceramic composition. For this reason, the multilayer ceramic capacitor of this embodiment has a high relative dielectric constant, good DC bias characteristics (dependence of the dielectric constant on the DC voltage application), reduced electrostriction during voltage application, and capacitance. The temperature characteristics can be improved. In particular, with respect to the capacity-temperature characteristic, the X6S characteristic of the EIA standard (−55 to 105 ° C., ΔC / C = within ± 22%) can be satisfied.

  Moreover, in the present embodiment, the dielectric layer 2 has the above-described configuration, and an electrode paste containing a predetermined common material is used as the electrode paste for forming the internal electrode layer 3. Therefore, the high temperature accelerated life can be improved and the reliability can be improved while maintaining the specific dielectric constant, the DC bias characteristic, the effect of reducing the amount of electrostriction during voltage application, and the capacity-temperature characteristic.

In the present embodiment, while realizing a high dielectric constant of 500 or more, the electrostriction amount when the voltage is applied has the following characteristics.
When the number of dielectric layers 2 sandwiched between the pair of internal electrode layers 3 is N layers, the ceramic capacitor is fixed to the substrate, and the ceramic capacitor fixed to the substrate is AC: 0.2 Vrms / μm. The amount of electrostriction defined by the vibration width of the surface of the element body 10 when a voltage is applied under the conditions of DC: 4 V / μm and frequency: 1 kHz is preferably less than 0.125 N [nm], more preferably 0. .1 N [nm] or less. That is, for example, when the number of dielectric layers 2 sandwiched between the pair of internal electrode layers 3 is 100, the amount of electrostriction is preferably less than 12.5 nm, more preferably 10 nm or less. be able to. As the substrate, a normal substrate on which the multilayer ceramic capacitor 1 is mounted, for example, a glass epoxy substrate printed with a predetermined electrode pattern may be used.

  The values of AC and DC under the above voltage application conditions are applied voltages per 1 μm thickness of the dielectric layer. That is, for example, when the thickness of the dielectric layer is 5 μm, the applied voltage is AC: 1.0 Vrms (= 0.2 Vrms / μm × 5 μm) and DC: 20 V (= 4 V / μm × 5 μm). Further, the amount of electrostriction tends to change as the thickness of the dielectric layer 2 changes. Therefore, in this embodiment, when the thickness of the dielectric layer 2 is preferably 2 to 20 μm, particularly 5 μm, it is preferable to be within the predetermined range.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the embodiment mentioned above at all, and can be variously modified within the range which does not deviate from the summary of this invention.

  For example, in the above-described embodiment, the multilayer ceramic capacitor is exemplified as the multilayer electronic component according to the present invention. However, the multilayer electronic component according to the present invention is not limited to the multilayer ceramic capacitor and has the above-described configuration. Anything is fine.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.

Example 1
Preparation of Dielectric Paste First, BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder are used as the main component materials, and MnCO ₃ , V ₂ O ₅ and SiO ₂ are used as the main component materials. TiO ₂ was prepared as a raw material for adjusting the ratio of B, B (Ba, Sr and Ca and Ti). In addition, MnCO ₃ which is a raw material of the subcomponent is a compound that becomes MnO after firing.

Subsequently, each raw material prepared above was wet pulverized with a ball mill for 15 hours and dried to obtain a dielectric material. In addition, the mixing ratio of each raw material was adjusted so that the composition after baking became the composition shown in Table 1. However, in Table 1, the addition amount of each subcomponent is the number of moles with respect to 100 moles of the main component, MnO and SiO ₂ are converted into oxides, and V ₂ O ₅ is converted into V element. Indicated.

  Next, 100 parts by weight of the obtained dielectric material, 10 parts by weight of polyvinyl butyral resin, 5 parts by weight of dibutyl phthalate (DOP) as a plasticizer, and 100 parts by weight of alcohol as a solvent are mixed with a ball mill to obtain a paste. Dielectric paste was obtained.

Preparation of Electrode Paste First, BaTiO ₃ powder, SrTiO ₃ powder, CaTiO ₃ powder, MnCO ₃ , V ₂ O ₅ and SiO ₂ were prepared as common materials. These prepared co-materials, Ni powder as a conductor powder, and organic vehicle were mixed with a ball mill to obtain a paste, thereby obtaining an electrode paste. MnCO ₃ is a compound that becomes MnO after firing.

In this example, when the content ratios of BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder are expressed by the formula {(Ba _α , Sr _β , Ca _γ ) O} _n TiO ₂ , The symbols α, β, γ and n were adjusted to the values shown in Table 1. Moreover, the content ratio of MnCO ₃ , V ₂ O ₅ and SiO ₂ was shown by the number of moles relative to a total of 100 moles of BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder. However, in Table 1, MnO and SiO ₂ are addition amounts in terms of oxides, and V ₂ O ₅ is an addition amount in terms of V elements.
In this example, the electrode paste was prepared so that the content of the common material was 20 parts by weight with respect to 100 parts by weight of the Ni powder.

Production of Multilayer Ceramic Capacitor Sample The multilayer ceramic capacitor 1 shown in FIG. 1 was produced using the dielectric paste produced above and the electrode paste as follows.

  First, a green sheet was formed on a PET film by the doctor blade method using the obtained dielectric paste. Next, an electrode pattern was printed on the green sheet by screen printing using an electrode paste to produce a green sheet on which the electrode pattern was printed. The thickness of the green sheet on which the electrode pattern was printed was 6.5 μm after drying. Next, separately from the above green sheet, a green sheet on which no electrode pattern was printed on the PET film was manufactured by a doctor blade method using a dielectric paste.

And each green sheet manufactured above was laminated | stacked in the following order, and the green chip | tip was manufactured by pressing the obtained laminated body.
First, green sheets on which no electrode patterns were printed were laminated until the total thickness reached 300 μm. On top of that, five green sheets printed with electrode patterns were laminated. Further thereon, a green sheet on which no electrode pattern was printed was laminated until the total thickness reached 300 μm to obtain a laminate. The obtained laminate was heated and pressurized under the conditions of a temperature of 80 ° C. and a pressure of 1 t / cm ² to obtain a green chip.

Next, the obtained green chip was cut into a predetermined size and subjected to binder removal processing, firing and annealing under the following conditions to obtain a multilayer ceramic fired body.
The binder removal treatment conditions were temperature rising rate: 30 ° C./hour, holding temperature: 250 ° C., temperature holding time: 8 hours, and atmosphere: in the air.
Firing conditions are: temperature rising rate: 200 ° C./hour, holding temperature: 1240 ° C., temperature holding time: 2 hours, cooling rate: 200 ° C./hour, atmospheric gas: a mixed gas of humidified N ₂ and H ₂ (H ₂ : 3%).
The annealing condition was a Atsushi Nobori rate: 200 ° C. / hour, holding temperature: 1000 ° C., a temperature holding time: 2 hours, cooling rate: 200 ° C. / time, the atmospheric gas of a wet _{N 2} gas.
A wetter with a water temperature of 20 ° C. was used for humidifying the atmospheric gas during firing and annealing.

  Next, after polishing the end face of the obtained multilayer ceramic fired body by sand blasting, In-Ga was applied as an external electrode to obtain samples 1 to 13 of the multilayer ceramic capacitor shown in FIG. The size of the obtained capacitor sample is 2.5 mm × 2.5 mm × 3.2 mm, the thickness of the dielectric layer is 5 μm, the thickness of the internal electrode layer is 1.5 μm, and the dielectric layer sandwiched between the internal electrode layers is The number was 4.

  About each obtained capacitor | condenser sample, the capacitance temperature characteristic (X6S characteristic), a dielectric constant, a high temperature accelerated lifetime (HALT), a DC bias characteristic, and the amount of electrostriction by voltage application were measured by the method shown below.

Capacity-temperature characteristics (X6S characteristics)
For the capacitor sample, the capacitance at each temperature of −55 ° C., 25 ° C. and 105 ° C. was measured, and the change rate ΔC of the capacitance at −55 ° C. and 105 ° C. with respect to the capacitance at 25 ° C. (unit: %) Was calculated. In this example, a sample in which the rate of change in electrostatic capacitance satisfies the X6S characteristic of the EIA standard (−55 to 105 ° C., ΔC = within ± 22%) is considered good. The results are shown in Table 1. In Table 1, samples that satisfy the X6S characteristics are indicated by “◯”, and samples that do not satisfy the X6S characteristics are indicated by “X”.

Dielectric constant ε
First, at a reference temperature of 25 ° C., a capacitor with a frequency of 1 kHz and an input signal level (measurement voltage) of 1.0 Vrms is input with a digital LCR meter (YHP 4284A), and the capacitance C is measured. did. Then, the relative dielectric constant ε (no unit) was calculated based on the thickness of the dielectric layer, the effective electrode area, and the capacitance C obtained as a result of the measurement. It is preferable that the relative dielectric constant is high. In this example, 500 or more was considered good. The results are shown in Table 1.

High temperature accelerated life (HALT )
The high temperature accelerated life (HALT) was evaluated by maintaining the obtained sample at 175 ° C. in a DC voltage application state of 8 V / μm and measuring the average life time. In this example, the time from the start of application until the insulation resistance drops by two digits was defined as the lifetime. The high temperature accelerated life was evaluated for 10 capacitor samples and averaging the results. The results are shown in Table 1.

The DC bias characteristic was measured by calculating the change in relative permittivity (unit:%) when a DC voltage of 4 V / μm was applied to a DC bias characteristic capacitor sample at a constant temperature (25 ° C.). In this example, the DC bias characteristic was an average value of values measured using 10 capacitor samples. The DC bias characteristic is preferably as close to 0 as possible, and in this example, −10% or more was considered good. The results are shown in Table 1.

Electrostriction due to voltage application First, the capacitor sample was fixed by soldering to a glass epoxy substrate on which electrodes of a predetermined pattern were printed. Next, a voltage is applied to the capacitor sample fixed on the substrate under the conditions of AC: 0.2 Vrms / μm, DC: 4 V / μm, and frequency: 1 kHz, and the vibration width of the capacitor sample surface during voltage application is measured. This was the amount of electrostriction. A laser Doppler vibrometer was used to measure the vibration width of the capacitor sample surface. In this example, the average value of values measured using 10 capacitor samples was used as the amount of electrostriction. The electrostriction amount is preferably low. In this example, the electrostriction amount was 0.5 nm or less (0.125 N [nm] or less, N = 4) in any of the samples, which was a favorable result.

Table 1 shows the composition of the dielectric layers of Sample Nos. 1 to 13, the composition of the common material in the electrode paste, and the evaluation results of each characteristic. Sample No. 8 is a sample to which BaTiO ₃ powder is not added as a common material, Sample No. 10 is a sample to which no CaTiO ₃ powder is added as a common material, and Sample No. 12 is an SrTiO ₃ powder as a common material. This sample was not added.

From the results of the sample numbers 1 to 7, the electrode paste contains BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder as co-materials, and the content ratio thereof is expressed by the formula {(Ba _α , Sr _β , Ca _γ ) O} _n TiO ₂ , 0.1 ≦ α ≦ 0.7, 0.1 ≦ β ≦ 0.7, 0.1 ≦ γ ≦ 0.7, α + β + γ = 1, 0.8 ≦ It can be confirmed that by setting the range of n ≦ 1.3, it is possible to improve the high-temperature accelerated life while keeping the relative permittivity, DC bias characteristics, electrostriction amount at the time of voltage application, and capacity-temperature characteristics good. .

On the other hand, in the sample number 8 in which the BaTiO ₃ powder was not added as a common material (that is, α = 0), the dielectric constant was less than 500, and the addition amount of the BaTiO ₃ powder as the common material was too large (that is, α Sample No. 9 resulted in deterioration of the high temperature accelerated lifetime (HALT) and DC bias characteristics.
Further, SrTiO ₃ powder and CaTiO ₃ powder were not added as co-materials (that is, β = 0 or γ = 0), and sample numbers 10 and 12, and the addition amounts of SrTiO ₃ powder and CaTiO ₃ powder as co-materials were Sample numbers 11 and 13 that were too much (that is, β or γ was too large) were inferior in capacity-temperature characteristics and did not satisfy the X6S characteristics.

Incidentally, the sample No. 1-5, by comparing the sample numbers 6 and 7, and a α a content of BaTiO ₃ powder in the common material constituting the electrode paste, the BaTiO ₃ in the dielectric layer It can be confirmed that the effect of improving the high temperature accelerated life (HALT) can be further enhanced by setting the relationship between the content ratio x and α ≦ x.

Example 2
The composition of the dielectric layer is changed as shown in Table 2, and the ratio of the A site to the B site of BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder to be included as a co-material in the electrode paste (Ba, Capacitor samples (sample numbers 14 to 17 shown in Table 2) were prepared in the same manner as sample number 5 in Example 1, except that the value of n, which is the ratio of Sr and Ca to Ti, was changed. Then, evaluation was performed in the same manner as in Example 1. In addition, the value of n was adjusted by the method of further using TiO ₂ as a raw material or the method of further using BaCO ₃ , SrCO ₃ , and CaCO ₃ .

Example 3
The composition of the dielectric layer is shown in Table 2, and the same as Sample No. 5 of Example 1 except that the electrode paste did not contain MnO, V ₂ O ₅ and SiO ₂ as co-materials. A capacitor sample (sample number 18 shown in Table 2) was prepared and evaluated in the same manner as in Example 1.

  Table 2 shows the composition of the dielectric layers of sample numbers 5 and 14 to 18, the composition of the co-material in the electrode paste, and the evaluation results of each characteristic. Sample No. 5 is the same sample as Sample No. 5 in Example 1.

Sample numbers 5 and 14 in which the value of n, which is the ratio of the A site to the B site (ratio of Ba, Sr and Ca, and Ti) of the BaTiO ₃ powder, SrTiO ₃ powder, and CaTiO ₃ powder, was changed. From the results of -17, it can be confirmed that if the value of n is too small, the high temperature accelerated life (HALT) is deteriorated, whereas if the value of n is too large, the sintering becomes insufficient.

Further, from the result of the sample number 18, the effect of the present invention is obtained even when only BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder are used as the co-material without using MnO, V ₂ O ₅ and SiO _2. Can be confirmed.

Example 4
Capacitor samples (sample numbers 19 to 23 shown in Table 3) were prepared in the same manner as Sample No. 5 in Example 1, except that the amount of common material added in the electrode paste was changed as shown in Table 3. Then, evaluation was performed in the same manner as in Example 1. The results are shown in Table 3.

  Table 3 shows the additive amount of the common material in the electrode pastes of sample numbers 5 and 19 to 23, and the evaluation results of the characteristics. Sample No. 5 is the same sample as Sample No. 5 in Example 1. In addition, sample number 23 was markedly “-” in the table because it was extremely inferior in high-temperature accelerated life characteristics and the life time could not be measured.

  From the result of the sample number 19, if the added amount of the common material in the electrode paste is too small, cracks occur. On the other hand, if the added amount of the common material in the electrode paste is too large, the capacity It can be confirmed that the temperature characteristics are deteriorated, the X6S characteristics cannot be satisfied, and the high temperature accelerated life characteristics are extremely inferior due to the influence of the electrode interruption.

FIG. 1 is a cross-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 main body 2 ... Dielectric layer 3 ... Internal electrode layer 4 ... External electrode

Claims (10)

A method of manufacturing a multilayer electronic component having a configuration in which dielectric layers and internal electrode layers are alternately laminated,
Forming a green sheet to be a dielectric layer after firing;
Using an electrode paste to form an electrode paste film that becomes an internal electrode layer after firing;
Alternately stacking the green sheet and the electrode paste film to obtain a green chip;
Firing the green chip,
The dielectric layer after firing contains BaTiO ₃ , SrTiO ₃ and CaTiO ₃ as main components, and the BaTiO ₃ , SrTiO ₃ and CaTiO ₃ are not substantially dissolved in each other, and composite Consisting of a dielectric porcelain composition forming the structure,
As the electrode paste for forming the electrode paste film, an electrode paste containing a conductor powder and a co-material containing BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder is used. Manufacturing method of parts. When the content ratio of the BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder in the electrode paste is represented by the formula {(Ba _α , Sr _β , Ca _γ ) O} _n TiO ₂ , The symbols α, β, γ and n are
0.1 ≦ α ≦ 0.7,
0.1 ≦ β ≦ 0.7,
0.1 ≦ γ ≦ 0.7,
α + β + γ = 1,
0.8 ≦ n ≦ 1.3,
The method of manufacturing a multilayer electronic component according to claim 1. Said dielectric ceramic composition, said BaTiO _3, SrTiO ₃ and composition molar ratio of CaTiO ₃ which contained as a main component, in the case shown by a composition formula _{{(Ba x Sr y Ca z} ) O} m TiO 2 , Symbols x, y, z and m in the above formula are
0.19 ≦ x ≦ 0.23,
0.25 ≦ y ≦ 0.31,
0.46 ≦ z ≦ 0.54,
x + y + z = 1,
0.980 ≦ m ≦ 1.01,
The method for manufacturing a multilayer electronic component according to claim 1, wherein: Wherein the dielectric ceramic composition, said BaTiO _3, SrTiO ₃ and composition molar ratio of CaTiO ₃ which contained as a main component, a composition formula _{{(Ba x Sr y Ca z} ) O} m TiO 2 ( provided that the equation In the case of x + y + z = 1),
The relation between α, which is the ratio of the BaTiO ₃ powder in the electrode paste, and x, which is the ratio of the BaTiO ₃ in the dielectric ceramic composition, satisfies α ≦ x. Manufacturing method for multilayer electronic components. The composition formula _{{(Ba x Sr y Ca z} ) O} m TiO 2 symbols x, y, z and m,
0.19 ≦ x ≦ 0.23,
0.25 ≦ y ≦ 0.31,
0.46 ≦ z ≦ 0.54,
0.980 ≦ m ≦ 1.01,
The method for manufacturing a multilayer electronic component according to claim 4. The common material constituting the electrode paste is:
A compound of Mn;
A compound of Si;
One or more selected from compounds of each element of V, Ta, Nb, W, Mo and Cr,
For a total of 100 moles of BaTiO ₃ powder, SrTiO ₃ powder and CaTiO ₃ powder,
The content of the Mn compound is 0.3 to 1 mol in terms of MnO,
The content of the Si compound is 0.1 to 0.5 mol in terms of SiO ₂ ,
The content of the compound of V, Ta, Nb, W, Mo and Cr is 0.02 mol or more and less than 0.40 mol in terms of each element of V, Ta, Nb, W, Mo and Cr. Item 6. A method for manufacturing a multilayer electronic component according to any one of Items 1 to 5.   The method for producing a multilayer electronic component according to claim 1, wherein the content of the common material in the electrode paste is 1 to 30 parts by weight with respect to 100 parts by weight of the conductor powder. . Manufactured by the method according to claim 1,
Dielectric porcelain containing BaTiO ₃ , SrTiO ₃ and CaTiO ₃ as main components, and the BaTiO ₃ , SrTiO ₃ and CaTiO ₃ are not substantially dissolved in each other to form a composite structure. A dielectric layer comprising a composition;
A multilayer electronic component having an internal electrode layer;   The multilayer electronic component according to claim 8, wherein an average crystal particle diameter of the dielectric particles constituting the dielectric layer is 0.2 to 2 μm.   The multilayer electronic component according to claim 8, wherein the dielectric layer has a thickness of 2 to 20 μm.

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