JP2016058719A - Multilayer ceramic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer ceramic capacitor capable of preventing degradation of insulation resistance by reducing an influence of hydrogen generated in a plating step.SOLUTION: A multilayer ceramic capacitor 1 includes at least one kind of an element forming hydrogen and a covalent bonded hydride (except for elements generating a hydride having a boiling point of less than 125°C) and an element forming hydrogen and a hydride at a boundary region between an outermost layer of a plating layer 13c constituting an external electrode 13 and a dielectric layer 10 constituting a ceramic element 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a multilayer ceramic capacitor, and more particularly to the structure of external electrodes and internal electrodes of the multilayer ceramic capacitor.

  A multilayer ceramic capacitor is formed in a ceramic body that is electrically connected to a ceramic body composed of a plurality of laminated dielectric layers, a plurality of internal electrodes disposed between the dielectric layers, and the internal electrodes. And a pair of external electrodes. The surface of the external electrode is Ni-plated to prevent solder erosion at the time of mounting. Further, in order to improve solderability at the time of soldering and mounting, on the Ni plating film Sn plating is given. The plating of Ni, Sn, etc. is usually formed by an electrolytic plating method.

  In Patent Document 1, hydrogen ions are generated by a chemical reaction in the plating process, and the hydrogen ions are occluded in the internal electrode, and the surrounding dielectric layer is gradually reduced to deteriorate the insulation resistance. It is described to wake up. As a solution, when an internal electrode mainly composed of a noble metal (for example, Ag—Pd alloy) is used, a metal (for example, Ni) that deactivates hydrogen absorption is added to the internal electrode. It is described to do.

Japanese Patent Laid-Open No. 1-80011

  However, in recent years, in order to reduce the material cost, a base metal such as Ni is often used instead of a noble metal such as Ag or Pd as a material for the internal electrode. Further, although Patent Document 1 describes that Ni is “a metal that inactivates absorption of hydrogen”, according to research by the inventors, even if the internal electrode is Ni, It has been found that the influence of this leads to deterioration of insulation resistance.

  The present invention solves the above-described problems, and an object of the present invention is to provide a multilayer ceramic capacitor capable of reducing the influence of hydrogen generated in a plating process and preventing deterioration of insulation resistance.

  As described above, conventionally, it has been considered that hydrogen generated in the plating process affects the deterioration of the insulation resistance. The inventors conducted research on the deterioration of the insulation resistance described above, and most of the hydrogen generated in the plating process was once stored in the external and internal electrodes, and when a temperature was applied to the multilayer ceramic capacitor and a voltage was applied. It was found that it diffused and reached the dielectric layer. The inventors have further experimented and studied based on this knowledge, and have completed the present invention.

That is, the multilayer ceramic capacitor of the present invention is
A ceramic body having a plurality of laminated dielectric layers, and having both end faces facing each other and a plurality of side faces connecting the both end faces;
Containing a base metal as a main component, disposed between the laminated dielectric layers, and a plurality of internal electrodes alternately drawn to both end faces;
An external electrode body formed on the ceramic body so as to be electrically connected to the internal electrodes drawn to the both end faces of the ceramic body, and at least one plating layer formed outside the external electrode body. A multilayer ceramic capacitor comprising: an external electrode having:
An element that forms a covalent hydride with hydrogen between the outermost plating layer and the dielectric layer of the plating layer (excluding an element that forms a hydride having a boiling point of less than 125 ° C.) And at least one element forming a hydride in the boundary region with hydrogen.

  In the above, an element that forms a covalent hydride with hydrogen (excluding an element that generates a hydride having a boiling point of less than 125 ° C.) refers to In and Tl in the long-period periodic table. Except boron group, carbon group, nitrogen group, oxygen group, halogen, and hydrogen are elements capable of forming a compound. The element forming the hydride in the boundary region with hydrogen is an element at the boundary between the covalent hydride and the metal-like hydride, and Al in the long-period periodic table. Boron group excluding Ga, Group 11 and Group 12, and hydrogen are elements capable of forming a compound.

In addition, the internal electrode and the external electrode main body are included between the outermost plating layer and the dielectric layer, and of course, between the outermost plating layer and the external electrode main body, and between the external electrode main body and the internal electrode. Or a conductor is formed at the interface between the internal electrode and the dielectric layer.
The element may be present between the outermost plating layer and the dielectric layer as a single element, or may be bonded to another element between the outermost plating layer and the dielectric layer. You may do it. The hydrogen includes any state such as hydrogen atom, hydrogen ion, hydrogen molecule, and hydrogen isotope. The hydrogen referred to here is hydrogen generated mainly by electrolysis in the plating step, but also includes hydrogen present as plating solution or water generated by condensation or water vapor in the atmosphere.

  When the external electrode main body contains the element, hydrogen can be held in the external electrode main body to suppress hydrogen diffusion from the external electrode main body.

  Also, when the internal electrode contains the element, hydrogen can be held in the internal electrode to suppress the diffusion of hydrogen from the internal electrode to the dielectric layer.

In addition, another multilayer ceramic capacitor of the present invention is
A ceramic body having a plurality of laminated dielectric layers, and having both end faces facing each other and a plurality of side faces connecting the both end faces;
Containing a base metal as a main component, disposed between the laminated dielectric layers, and a plurality of internal electrodes alternately drawn to both end faces;
An external electrode body formed on the ceramic body so as to be electrically connected to the internal electrodes drawn to the both end faces of the ceramic body, and at least one plating layer formed outside the external electrode body. A multilayer ceramic capacitor comprising: an external electrode having:
The interface between the internal electrode and the external electrode body, the outer surface of the external electrode body, the inside of the external electrode body, the interface between the internal electrode and the dielectric layer, and the plating layer includes a plurality of layers. Elements that form a covalent bond hydride with hydrogen at the interface between the outermost plating layer and the inner plating layer (except for elements that generate hydrides with a boiling point of less than 125 ° C) And a hydrogen holding film containing at least one element forming a hydride in the boundary region with hydrogen.

  The hydrogen retaining film in the above may be formed continuously, or may be partially present, or may be present in the form of a mesh or a line.

  The element is preferably at least one selected from the group consisting of Sn, Bi, Al, Ag, Zn, Au, In, Ga, Ge, and Si.

Since Sn, Bi, Al, Ag, Zn, Au, In, Ga, Ge, and Si are bonded to hydrogen and then hold the hydrogen, diffusion of hydrogen into the dielectric layer can be suppressed.
Among these elements, Sn, Bi, and Al are particularly preferable elements because they have a low melting point and easily form an alloy.

  In the multilayer ceramic capacitor of the present invention, an element that forms a covalent bond hydride with hydrogen (except an element that generates a hydride having a boiling point of less than 125 ° C.) between the outermost plating layer and the dielectric layer. ) And at least one element forming a hydride in the boundary region with hydrogen, so that hydrogen generated in the plating process is held between the outermost plating layer and the dielectric layer. Can do. Thereby, diffusion of hydrogen into the dielectric layer can be suppressed, and deterioration of insulation resistance (IR) can be prevented.

Alternatively, another multilayer ceramic capacitor of the present invention includes an interface between the internal electrode and the external electrode body, an outer surface of the external electrode body, an inside of the external electrode body, an interface between the internal electrode and the dielectric layer, and a plating layer. In the case where has a plurality of layers, an element which forms a covalent bond hydride with hydrogen at the interface between the outermost plating layer and the inner plating layer (however, a hydride having a boiling point of less than 125 ° C is generated. And a hydrogen holding film containing at least one element forming a hydride in the boundary region with hydrogen, so that hydrogen is held by the hydrogen holding film, Hydrogen diffusion can be suppressed.
In addition, the hydrogen retaining film includes the interface between the internal electrode and the dielectric layer, the interface between the internal electrode and the external electrode body, the outer surface of the external electrode body, the inside of the external electrode body, and the interface between the internal electrode and the dielectric layer. When the plating layer is formed of a plurality of layers, it may be disposed at one of the interfaces between the outermost plating layer and the inner plating layer. However, a configuration in which two or more are provided is also possible.

It is sectional drawing of the multilayer ceramic capacitor concerning Embodiment 1 of this invention. It is a figure for demonstrating the junction part of the internal electrode and external electrode main body of the multilayer ceramic capacitor concerning Embodiment 1 of this invention. It is a Sn mapping figure obtained by analyzing the section of the multilayer ceramic capacitor concerning Embodiment 1 of the present invention by FE-WDX method (electrolytic radiation-wavelength dispersion type X-ray analysis method). It is sectional drawing of the multilayer ceramic capacitor concerning Embodiment 2 of this invention. It is sectional drawing of the multilayer ceramic capacitor concerning Embodiment 3 of this invention. It is sectional drawing of the multilayer ceramic capacitor concerning Embodiment 4 of this invention. It is sectional drawing of the multilayer ceramic capacitor concerning Embodiment 5 of this invention.

[Embodiment 1]
A multilayer ceramic capacitor 1 according to a first embodiment of the present invention will be described with reference to FIG. The multilayer ceramic capacitor 1 includes a plurality of stacked dielectric layers 10, a ceramic body 11 having both end faces 11 a facing each other, and a plurality of side faces 11 b connecting the both end faces 11 a, and stacked dielectric layers 10, a plurality of internal electrodes 12 that are alternately drawn to both end faces 11 a of the ceramic body 11, and a pair of external electrodes 13 that are formed so as to be electrically connected to the internal electrodes 12.

The ceramic body 11 has a substantially rectangular parallelepiped shape composed of both end faces 11a and four side faces 11b, and has corners and ridges chamfered and rounded. As a material constituting the dielectric layer 10, a BaTiO ₃ dielectric ceramic is used. In addition, a dielectric ceramic whose main component is CaTiO ₃ , SrTiO ₃ , CaZrO ₃ or the like can be used.

  The internal electrodes 12 are formed so as to be alternately exposed at both end faces 11 a of the ceramic body 11. As the conductive material constituting the internal electrode 12, a material mainly composed of Ni is used. In addition, a base metal mainly composed of Cu or the like can be used.

  The external electrode 13 is formed on both end surfaces 11a of the ceramic body 11, and includes an external electrode body 13a formed so as to be electrically connected to the internal electrode 12, and plating layers 13b and 13c formed outside the external electrode body 13a. Have. The external electrode main body 13a is formed by applying a conductive paste containing metal powder and glass to the end face 11a of the ceramic body 11 and baking it. As a material constituting the external electrode main body 13a, a metal mainly composed of Cu is used. In addition, a conductive material mainly containing Ni or the like can be used. The thickness of the external electrode body 13a such as Ni is 1 to 100 μm, for example.

  The plating layers 13b and 13c are composed of a plating layer 13b formed on the outer surface of the external electrode body 13a and an outermost plating layer 13c formed on the outer surface of the plating layer 13b. Ni is used as a material constituting the plating layer 13b, and Sn is used as a material constituting the plating layer 13c. In addition, a metal such as Pd, Cu, or Au can be used as the outermost plating layer 13c. The thickness of each plating layer 13b and 13c is 0.1-20 micrometers, for example. The plating layers 13b and 13c were formed by an electrolytic plating method. The plating layer is not limited to a plurality of layers, and may be composed of a single layer of metal such as Cu.

In the multilayer ceramic capacitor 1 of this embodiment, an element that forms a covalent bond hydride with hydrogen in the conductive path body 15 that connects the plating layer 13b and the dielectric layer 10 on the surface of the external electrode body 13a ( However, except for an element that generates a hydride having a boiling point of less than 125 ° C.) and at least one element (hydrogen holding element) that forms a hydride in the boundary region with hydrogen.
In the first embodiment, the external electrode main body 13b constituting a part of the conductive path body 15 is made to contain a hydrogen holding element.

  Here, the conductive path body 15 is a conductive path formed between the plating layer 13b on the surface of the external electrode body 13a and the dielectric layer 10, and includes the internal electrode 12 and the external electrode body 13a. It is. Further, when another conductor is formed at the interface between the plating layer 13b and the external electrode body 13a, the interface between the external electrode body 13a and the internal electrode 12, or the interface between the internal electrode 12 and the dielectric layer 10. It also includes it.

  In addition, elements that form a covalent hydride with hydrogen (excluding elements that generate hydrides having a boiling point of less than 125 ° C.) exclude In and Tl in the long-period periodic table. Boron group (B, Al, Ga), carbon group (C, Si, Ge, Sn, Pb), nitrogen group (N, P, As, Sb, Bi), oxygen group (O, S, Se, Te, Po), halogen (F, Cl, Br, I, At) and hydrogen are elements capable of forming a compound. The element forming the hydride in the boundary region with hydrogen is an element at the boundary between the covalent hydride and the metal-like hydride, and Al in the long-period periodic table. Boron group (In, Tl) excluding Ga, Group 11 (Cu, Ag, Au), Group 12 (Zn, Cd, Hg) and hydrogen are elements capable of forming a compound. These elements form stable compounds with hydrogen. That is, once combined with hydrogen, energy is required to release the hydrogen, and it is difficult to release hydrogen. By utilizing this property, hydrogen generated in the plating process can be held in the conductive path body 15 described above.

In order to make the external electrode main body 13a constituting a part of the conductive path body 15 contain a hydrogen holding element, in this embodiment, in the conductive paste used to form the external electrode main body 13a, the above-described hydrogen holding in a metal state Elemental powder (hydrogen-retaining metal powder) was blended. The ratio of the hydrogen-retaining metal powder blended in the conductive paste is preferably a solid content ratio of 1 to 40 vol%.
The hydrogen holding metal may be present in the external electrode main body 13a as a single metal, and depending on the case, it may be dispersed or alloyed with other metals of the external electrode main body 13a. May be.

Here, the cross section of the multilayer ceramic capacitor 1 to which Sn was added as a hydrogen holding element was observed by the FE-WDX method (electrolytic radiation-wavelength dispersive X-ray analysis method).
FIG. 2 shows a cross section of a multilayer ceramic capacitor 1 in which an external electrode body 13a is formed using a conductive paste containing Cu as a main component to which Sn is added as a hydrogen holding metal. It is a mapping figure of Sn (hydrogen holding | maintenance metal) obtained by analyzing by a line analysis method.
The sample for analysis was prepared by polishing the multilayer ceramic capacitor 1 along the direction orthogonal to the end face 11a of the ceramic body 11 and the uppermost dielectric layer 10 until the volume thereof was about ½, This was prepared by milling the polishing sag. And the sample produced as mentioned above was analyzed on condition of the following by FE-WDX method.
Acceleration voltage: 15.0kV
Irradiation current: 5 × 10 −8 A
Magnification: 3000 times
DwellTime (capture time for one pixel): 40 ms
Analysis depth: 1-2 μm

  As a result, as shown in FIG. 2, it is confirmed that Sn is present in the external electrode main body 13a and partly in the lead portion 12a of the internal electrode 12 drawn to the end face 11a of the ceramic body 11. It was.

<Evaluation test>
In order to confirm the significance of the multilayer ceramic capacitor 1 of this embodiment, different types of metal powders (Sn, Bi, Ag, Pd) as shown in Table 1 were added to a conductive paste containing Cu powder as a conductive component. Samples of sample numbers 1 to 5 in Table 1 were prepared using the conductive paste and the conductive paste to which no metal powder was added.

The detailed specifications of the conductive paste were as follows.
Solid content: 25 vol%
Ratio of Cu powder in solid content: 70 vol%
Ratio of glass in solid content: 25 vol%
Ratio of added metal powder in solid content: 5 vol%
Particle size of Cu powder: 3 μm
Glass particle size: 2 μm
Glass composition: BaO—SrO—B 2 O 3 —SiO 2 glass frit (glass frit in terms of oxide, BaO: 10 to 50 wt%, B 2 O 3: 3 to 30 wt%, SiO 2: 3 to 30 wt%, glass of the system It was used)

  And when producing the sample of sample numbers 1-5, this electrically conductive paste was apply | coated to the end surface 11a of the ceramic element | base_body 11, and it baked, and formed the external electrode main body 13a.

Thereafter, a plating layer 13b made of Ni was formed on the outside of the external electrode body 13a by electrolytic plating, and a plating layer 13c made of Sn was formed on the outside by electrolytic plating.
As a result, samples Nos. 1 to 5 in Table 1 were obtained.

  The produced multilayer ceramic capacitor generally has a capacity of 10 μF, a rated voltage of 6.3 V, dimensions of 1.0 mm in length, 0.5 mm in width, and 0.5 mm in height, and the thickness of the external electrode body 13 a is 25 μm ( The center of the end face), the thickness of the plating layer 13b is 3 μm, and the thickness of the plating layer 13c is 3 μm.

  And the PCBT test was done about the sample of sample numbers 1-5 of Table 1 produced in this way.

The PCBT test was performed under the conditions of a temperature of 125 ° C., a relative humidity of 95%, an applied voltage of 3.2 V, and a load time of 72 hours. And when insulation resistance (IR) was measured about each sample and it looked at LogIR, the case where IR value at the time of a test end fell 0.5 from IR value at the time of a test start was considered as IR degradation. Each sample is 20 pieces.
The results are shown in Table 1.

  In Table 1, samples Nos. 1 to 3 are samples that satisfy the requirements of the present invention, and Samples Nos. 4 and 5 are samples that do not satisfy the requirements of the present invention.

As shown in Table 1, no IR deterioration was observed in the sample No. 1 sample containing Sn and the sample No. 2 sample containing Bi in the external electrode body 13a. In addition, the sample of Sample No. 3 in which Ag was contained in the external electrode body 13a was less likely to cause IR deterioration.
On the other hand, in the sample No. 4 in which Pd was contained in the external electrode body 13a, particularly in the sample No. 5 in which no metal was added, generation of IR deterioration was recognized in large numbers.

  As described above, in the multilayer ceramic capacitor 1 of this embodiment, since the external electrode main body 13a contains the hydrogen holding element, the hydrogen generated in the plating process constitutes a part of the conductive path body 15. It can be absorbed and held by the external electrode body 13a. As a result, it is possible to suppress the diffusion of hydrogen into the dielectric layer 10 and prevent the insulation resistance (IR) from deteriorating.

  In the present invention, good results can be obtained even when a hydrogen holding element such as Sn is present inside the internal electrode 12. Also, good results can be obtained when Bi and Al are present in place of Sn.

  In the present invention, it is usually desirable that at least one of Sn, Bi, and Al is segregated at the junction between the internal electrode 12 and the external electrode body 13a as a hydrogen holding element.

  Here, the joint between the internal electrode 12 and the external electrode main body 13a will be described with reference to FIG. 1A. The end surface 12a of the internal electrode 12 exposed to the end surface 11a of the ceramic body 11 and the end surface of the ceramic body 11 This is an intermediate point R0 between one end portion (upper end portion in FIG. 1A) R1 and the other end portion (lower end portion in FIG. 1A) R2 in a region R in contact with the external electrode body 13a formed in 11a.

  That is, “..., at least one of Sn, Bi, and Al is largely segregated at the joint between the internal electrode 12 and the external electrode body 13 a...” Means that at least one of Sn, Bi, and Al. It means that many seeds are segregated at the position (joint part) indicated by R0 in FIG. 1A.

  In the above embodiment, the case where the external electrode main body 13a has a single layer structure has been described. However, the external electrode main body 13a has a multi-layer structure, and a predetermined layer or a plurality of layers of the external electrode main body 13a contains a hydrogen holding element. It is also possible to configure as described above.

[Embodiment 2]
A multilayer ceramic capacitor 1A according to Embodiment 2 of the present invention will be described with reference to FIG. In this multilayer ceramic capacitor 1A, as shown in FIG. 3, a hydrogen holding film 13e is formed at the interface between the external electrode body 13a and the internal electrode 12. In addition, about the structure which is common in the multilayer ceramic capacitor 1 of Embodiment 1, the same code | symbol is described in the figure explaining 1 A of multilayer ceramic capacitors of Embodiment 2, and description is abbreviate | omitted.

  The multilayer ceramic capacitor 1A includes an element that forms a covalent bond hydride with hydrogen at the interface between the external electrode body 13a and the internal electrode 12 (except for an element that generates a hydride having a boiling point of less than 125 ° C.), and And a hydrogen holding film 13e containing at least one element forming a hydride in the boundary region with hydrogen. The hydrogen holding film 13e is continuously formed on the end surface 11a of the ceramic body 11 so as to cover the lead portion 12a of the internal electrode exposed on the end surface 11a. However, the hydrogen holding film 13e may not be continuous, and may exist partially, or may exist in a form such as a mesh shape or a linear shape.

  In addition, about the structure which is common in the multilayer ceramic capacitor 1 of Embodiment 1, the same code | symbol is described in the figure explaining 1 A of multilayer ceramic capacitors of Embodiment 2, and description is abbreviate | omitted. The same applies to the following other embodiments.

  The hydrogen holding film 13e is formed by sputtering a hydrogen holding element (hydrogen holding metal) in a metal state, and is formed on the end face 11a of the ceramic body 11 in a metal film state. The hydrogen retaining film 13e can be formed by vapor deposition, plating, or the like.

<Evaluation test>
In order to confirm the significance of the multilayer ceramic capacitor 1A of this embodiment, a sample including a film formed by sputtering different kinds of metals (Sn, Bi, Al, Ag, Zn, Pd, Ti), that is, Samples Nos. 6 to 12 in Table 2 were prepared. In addition, a sample of Sample No. 13 in which no sputtering was performed and a hydrogen holding film was not formed was produced. The film thickness of the hydrogen holding film 13e was 1 μm.

  In addition, the thickness of the external electrode main body 13a was 15 micrometers (end surface center part). The specifications of the conductive paste for forming the external electrode main body 13a were solid content: 25 vol%, and the ratio of glass in the solid content: 25 vol%.

And about the sample of sample numbers 6-13 of Table 2 produced in this way, the test was done on the same conditions as the PCBT test performed in the above-mentioned Embodiment 1. FIG.
The results are shown in Table 2.

  In Table 2, samples Nos. 6 to 10 are samples that satisfy the requirements of the present invention, and Samples Nos. 11 to 13 are samples that do not satisfy the requirements of the present invention.

  As shown in Table 2, as the hydrogen retention film 13e, the sample No. 6 provided with the Sn film, the sample No. 7 provided with the Bi film, and the sample No. 8 provided with the Al film had an IR deterioration. Occurrence was not observed. In addition, the sample No. 9 provided with the Ag film and the sample No. 10 provided with the Zn film had little IR deterioration.

  On the other hand, the sample No. 11 in which the Pd film was formed by sputtering and the sample No. 12 in which the Ti film was formed frequently showed IR deterioration. In particular, in the sample of Sample No. 13 that was not sputtered, a large number of IR deteriorations were observed.

  From the above results, even when the hydrogen holding film 13e is provided at the interface between the external electrode main body 13a and the internal electrode 12, hydrogen generated in the plating process is absorbed by the hydrogen holding film 13e. It is possible to suppress and prevent diffusion to the dielectric layer 10 through the internal electrode 12.

  In the second embodiment, the case where the hydrogen holding film 13e is continuously formed on the end surface 11a of the ceramic body 11 so as to cover all the lead portions 12a of the internal electrodes has been described as an example. Significant effects can be obtained even when they are partially present, or in the form of a mesh or a line.

[Embodiment 3]
FIG. 4 is a view showing a multilayer ceramic capacitor 1B according to still another embodiment (Embodiment 3) of the present invention. In this multilayer ceramic capacitor 1B, a hydrogen holding film 13f is formed inside the external electrode body 13a. Specifically, the external electrode body 13a is composed of two layers of an external electrode body 13a1 mainly composed of Ni and an external electrode body 13a2 mainly composed of Cu. A hydrogen holding film 13f, which is a substantially continuous film having, is formed.

The hydrogen holding film 13f is formed by adding a hydrogen holding metal to the conductive paste for forming the second-layer external electrode body 13a2, applying the conductive paste to the first-layer external electrode body 13a1, and It is formed by simultaneously firing the electrode bodies 13a1 and 13a2.
The ratio of the hydrogen retaining metal added to the conductive paste is preferably in the range of 1 to 40 vol%.

<Evaluation test>
In order to confirm the significance of the multilayer ceramic capacitor 1B of this embodiment, different types of metal powders (Sn, Bi, Ag, Zn) as shown in Table 3 were added to a conductive paste containing Cu powder as a conductive component. Samples Nos. 14 to 19 in Table 1 were prepared using the conductive paste and the conductive paste to which no metal powder was added.

The amount of the metal powder added to the conductive paste for forming the second-layer external electrode body 13a2 was set to a ratio of 5 vol% of the solid content in the conductive paste. Other specifications were the same as in the first embodiment.
On the other hand, the specification of the conductive paste for forming the first-layer external electrode body 13a1 was as follows.
Solid content: 15 vol%
Co-material ratio in solid content: 40 vol%
Ratio of glass in solid content: 25 vol%
Particle size of Ni powder: 0.5 μm
Particle size of common material: 100 nm to 500 nm

And about the sample of sample numbers 14-19 of Table 3 produced in this way, the test was done on the same conditions as the PCBT test performed in the above-mentioned Embodiment 1. FIG.
The results are shown in Table 3.

  In Table 3, samples Nos. 14 to 17 are samples that satisfy the requirements of the present invention, and Samples Nos. 18 and 19 are samples that do not satisfy the requirements of the present invention.

As shown in Table 3, no IR deterioration was observed in the sample No. 14 in which Sn was blended into the second-layer external electrode body 13a2 and the sample No. 15 in which Bi was blended. In addition, the sample No. 16 containing Ag and the sample No. 17 containing Zn contained little IR deterioration.
In contrast, in the sample of sample number 18 in which Pd was blended in the second-layer external electrode body 13a2, much IR deterioration occurred. In particular, in the sample of Sample No. 19 to which no metal powder was added, IR deterioration occurred frequently.

  From the above results, even in the multilayer ceramic capacitor 1B having the configuration as shown in FIG. 4, hydrogen generated in the plating process is absorbed by the hydrogen holding film 13f, so that hydrogen passes through the internal electrode 12 and the dielectric layer 10. It was confirmed that the diffusion to the surface was suppressed and prevented, and the deterioration of IR was suppressed.

  In the case of the third embodiment, the hydrogen holding film 13f is preferably a continuous film. However, the hydrogen holding film 13f is not necessarily formed as a continuous film, and is not necessarily formed along the surface of the external electrode body 13a1. Or may exist in a form such as a mesh or a line. Moreover, it is not necessary that the film has a uniform thickness, and the film may be formed so that there is a difference in the distribution of the hydrogen retaining metal in the thickness direction.

[Embodiment 4]
FIG. 5 is a view showing a multilayer ceramic capacitor 1C according to still another embodiment (Embodiment 4) of the present invention. In this multilayer ceramic capacitor 1C, a hydrogen holding film 13g containing a hydrogen holding element is formed between the surface of the external electrode body 13a and the plating layer 13b, that is, on the outer surface of the external electrode body 13a.

  The hydrogen holding film 13g is formed by sputtering a hydrogen holding element (hydrogen holding metal) in a metal state, and is formed in a metal film state on the surface of the external electrode body 13a. Further, the hydrogen holding film 13g is continuously formed so as to cover the entire surface of the external electrode body 13a. The hydrogen holding film 13g can be formed by vapor deposition, plating, or the like.

<Evaluation test>
In order to confirm the significance of the multilayer ceramic capacitor 1C of this embodiment, a sample having a film formed by sputtering different kinds of metals (Sn, Bi, Al, Ag, Pd, Ti), ie, a table Sample Nos. 4 to 25 of No. 4 were prepared. In addition, a sample of Sample No. 26 in which no sputtering was performed and a hydrogen holding film was not formed was produced. The specification of the conductive paste for forming the external electrode body 13a was the same as that in the second embodiment.

And about the sample of sample numbers 20-26 of Table 4 produced in this way, the test was done on the same conditions as the PCBT test performed in the above-mentioned Embodiment 1. FIG.
The results are shown in Table 4.

  In Table 4, samples Nos. 20 to 23 are samples that satisfy the requirements of the present invention, and Samples Nos. 24 to 26 are samples that do not satisfy the requirements of the present invention.

As shown in Table 4, as the hydrogen retention film 13g, the sample No. 20 provided with the Sn film, the sample No. 21 provided with the Bi film, and the sample No. 22 provided with the Al film had an IR deterioration. The occurrence of was not observed.
In addition, the sample of Sample No. 23 provided with the Ag film had little IR deterioration.
On the other hand, the sample No. 24 in which the Pd film was formed by sputtering and the sample No. 25 in which the Ti film was formed showed much IR deterioration. Further, in the sample of sample number 26 which was not sputtered, a large number of IR deteriorations were observed.

  Also in the case of this monolithic ceramic capacitor 1C, the hydrogen holding film 13g is partially present between the surface of the external electrode body 13a and the plating layer 13b, or in a form such as a mesh or a line. You may do it. Even in that case, a significant effect can be obtained.

[Embodiment 5]
FIG. 6 is a view showing a multilayer ceramic capacitor 1D according to still another embodiment (Embodiment 5) of the present invention. In this multilayer ceramic capacitor 1D, a hydrogen holding film 13h containing a hydrogen holding element is formed between the outermost plating layer 13c and the inner plating layer 13b.

  The hydrogen holding film 13h is formed by sputtering a hydrogen holding element (hydrogen holding metal) in a metal state, and is formed in a metal film state on the outer surface of the plating layer 13b. The hydrogen holding film 13h is continuously formed so as to cover the entire surface of the plating layer 13b. The hydrogen holding film 13h can also be formed by vapor deposition, plating, or the like.

<Evaluation test>
In order to confirm the significance of the multilayer ceramic capacitor 1D of this embodiment, a sample provided with a film formed by sputtering different types of metals (Sn, Bi, Ag, Pd), that is, a sample number in Table 5 27-30 samples were prepared. In addition, a sample of Sample No. 31 was prepared without performing any particular sputtering and forming a hydrogen retaining film. The specification of the conductive paste for forming the external electrode body 13a was the same as that in the second embodiment.

And about the sample of sample numbers 27-31 of Table 5 produced in this way, the test was done on the same conditions as the PCBT test performed in the above-mentioned Embodiment 1. FIG.
The results are shown in Table 5.

  In Table 5, samples Nos. 27 to 29 are samples that satisfy the requirements of the present invention, and Samples Nos. 30 to 31 are samples that do not satisfy the requirements of the present invention.

As shown in Table 5, as the hydrogen retention film 13h, the sample No. 27 provided with the Sn film, the sample No. 28 provided with the Bi film, and the sample No. 29 provided with the Ag film had IR deterioration. There were few.
On the other hand, in the sample of sample number 30 in which the Pd film was formed by sputtering, much IR deterioration was observed. Further, in the sample of sample number 31 where sputtering was not performed, many IR deteriorations were observed.

  Also in the case of this multilayer ceramic capacitor 1D, the hydrogen retaining film 13h is partially present between the plated layer 13b and the plated layer 13c, or is present in a form such as a mesh or line. May be. Even in that case, a significant effect can be obtained.

  The present invention is not limited to the above embodiments, and various applications and modifications can be made within the scope of the invention.

DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C, 1D Multilayer ceramic capacitor 10 Dielectric layer 11 Ceramic body 11a End surface of ceramic body 12 Internal electrode 12a Leading part of internal electrode 13 External electrode 13a External electrode body 13b Surface plating of external electrode body Layer 13c Outermost plating layer 13e, 13f, 13g, 13h Hydrogen holding film 15 Conductive path body R One of the areas R1 in the area R where the end face of the internal electrode and the external electrode body formed on the end face of the ceramic body are in contact with each other End (upper end)
R2 The other side end (lower end) in region R
R0 Midpoint between one end R1 and the other end R2

Claims (5)

A ceramic body having a plurality of laminated dielectric layers, and having both end faces facing each other and a plurality of side faces connecting the both end faces;
Containing a base metal as a main component, disposed between the laminated dielectric layers, and a plurality of internal electrodes alternately drawn to both end faces;
An external electrode body formed on the ceramic body so as to be electrically connected to the internal electrodes drawn to the both end faces of the ceramic body, and at least one plating layer formed outside the external electrode body. A multilayer ceramic capacitor comprising: an external electrode having:
An element that forms a covalent hydride with hydrogen between the outermost plating layer and the dielectric layer of the plating layer (excluding an element that forms a hydride having a boiling point of less than 125 ° C.) And a multilayer ceramic capacitor comprising at least one element forming a hydride in a boundary region with hydrogen.   The multilayer ceramic capacitor according to claim 1, wherein the external electrode main body contains the element.   The multilayer ceramic capacitor according to claim 1, wherein the internal electrode contains the element. A ceramic body having a plurality of laminated dielectric layers, and having both end faces facing each other and a plurality of side faces connecting the both end faces;
Containing a base metal as a main component, disposed between the laminated dielectric layers, and a plurality of internal electrodes alternately drawn to both end faces;
An external electrode body formed on the ceramic body so as to be electrically connected to the internal electrodes drawn to the both end faces of the ceramic body, and at least one plating layer formed outside the external electrode body. A multilayer ceramic capacitor comprising: an external electrode having:
The interface between the internal electrode and the external electrode body, the outer surface of the external electrode body, the inside of the external electrode body, the interface between the internal electrode and the dielectric layer, and the plating layer includes a plurality of layers. Elements that form a covalent bond hydride with hydrogen at the interface between the outermost plating layer and the inner plating layer (except for elements that generate hydrides with a boiling point of less than 125 ° C) And a hydrogen holding film containing at least one element forming an hydride in the boundary region with hydrogen.   5. The element according to claim 1, wherein the element is at least one selected from the group consisting of Sn, Bi, Al, Ag, Zn, Au, In, Ga, Ge, and Si. Multilayer ceramic capacitor.