JP2021072325A - Multilayer ceramic capacitor and method for manufacturing multilayer ceramic capacitor - Google Patents

Abstract

To provide a multilayer ceramic capacitor in which the strength of the external surface of a ceramic element body is increased, so that the occurrence of cracks in a ceramic element body and the separation of an external electrode from a ceramic element body can be suppressed.SOLUTION: A multilayer ceramic capacitor includes: a ceramic element body 1 which has, as an external surface, a pair of main surfaces 1A, 1B facing each other in a height direction T, a pair of end surfaces 1C, 1D facing each other in a length direction L, and a pair of side surfaces 1E, 1F facing each other in a width direction W, and in which a plurality of ceramic layers 1a, 1b and a plurality of internal electrodes 2, 3 are layered; and at least two external electrodes 5, 6 which are formed on the external surface of the ceramic element body 1 and which are electrically connected to the internal electrodes 2, 3, respectively. The internal electrodes 2, 3 each include nickel as components, and the ceramic element body 1 includes nickel oxide 4 in at least a part on the external surface.SELECTED DRAWING: Figure 1

Description

The present invention relates to a multilayer ceramic capacitor, and more particularly, a laminated ceramic including a ceramic element in which a plurality of ceramic layers and a plurality of internal electrodes are laminated, and an external electrode formed on the outer surface of the ceramic element. Regarding capacitors.

The present invention also relates to a method for manufacturing a multilayer ceramic capacitor suitable for manufacturing the multilayer ceramic capacitor of the present invention.

Multilayer ceramic capacitors are widely used in electronic devices. Patent Document 1 (Japanese Unexamined Patent Publication No. 2003-243249) discloses a multilayer ceramic capacitor having a general structure.

The multilayer ceramic capacitor disclosed in Patent Document 1 includes a ceramic element in which a plurality of ceramic layers and a plurality of internal electrodes are laminated. At least two external electrodes are formed on the outer surface of the ceramic body. The external electrode is electrically connected to the internal electrode.

The monolithic ceramic capacitor disclosed in Patent Document 1 is manufactured by, for example, the following method. First, a ceramic green sheet is produced. Next, if necessary, a conductive paste for forming an internal electrode is applied to the main surface of the ceramic green sheet. Next, a plurality of ceramic green sheets are laminated and integrated to prepare an unfired ceramic element. Next, the unfired ceramic body is fired to prepare a ceramic body. Next, an external electrode is formed on the outer surface of the ceramic body.

In the method for manufacturing a multilayer ceramic capacitor described above, the quality is improved between the step of firing an unfired ceramic element to produce a ceramic element and the process of forming an external electrode on the outer surface of the ceramic element. For the purpose, a step of heating and annealing the ceramic body may be carried out.

JP-A-2003-243249

In the multilayer ceramic capacitor disclosed in Patent Document 1, the outer surface of the ceramic element may not have sufficiently high strength. If the outer surface of the ceramic element body does not have sufficient strength, there is a risk that cracks may occur in the ceramic element body and that the external electrode may be peeled off from the ceramic element body.

Therefore, the present invention provides a multilayer ceramic capacitor in which the strength of the outer surface of the ceramic body is enhanced and cracks are suppressed in the ceramic body and external electrodes are suppressed from peeling from the ceramic body. The purpose is to do. Another object of the present invention is to provide a method for manufacturing a multilayer ceramic capacitor suitable for manufacturing the multilayer ceramic capacitor of the present invention.

In order to solve the above-mentioned conventional problems, the monolithic ceramic capacitor according to an embodiment of the present invention has a pair of main surfaces facing each other in the height direction and a length orthogonal to the height direction as an outer surface. A plurality of ceramic layers and a plurality of internal electrodes laminated with a pair of end faces facing each other in the vertical direction and a pair of side surfaces facing each other in the width direction orthogonal to the height direction and the length direction. The ceramic element is provided with at least two external electrodes formed on the outer surface of the ceramic element and electrically connected to the internal electrode, the internal electrode containing nickel as a component, and the ceramic element. , It is assumed that at least a part of the outer surface is provided with nickel oxide.

Further, the method for manufacturing a multilayer ceramic capacitor according to an embodiment of the present invention includes a step of manufacturing a ceramic green sheet and a conductive paste for forming an internal electrode on the main surface of the ceramic green sheet, if necessary. A step of applying a plurality of ceramic green sheets to a desired shape, a step of laminating and integrating a plurality of ceramic green sheets to produce an unfired ceramic body, and a step of firing the unfired ceramic body to obtain a height as an outer surface. A pair of main surfaces facing each other in the direction and a pair of end faces facing each other in the length direction orthogonal to the height direction, and facing each other in the width direction orthogonal to the height direction and the length direction. A step of producing a ceramic element body having a pair of side surfaces, having a plurality of ceramic layers and a plurality of internal electrodes laminated, and having the internal electrodes drawn out to the outer surface, and heating the ceramic element body. It includes a step of annealing and a step of forming an external electrode electrically connected to the internal electrode on the outer surface of the ceramic body, and the conductive paste contains nickel as a component, so that the internal electrode becomes a component. In the step of annealing the ceramic element containing nickel, a part of the nickel contained in the component is separated from the internal electrode of the ceramic element, and the outer surface of the other ceramic element and / or the ceramic element. It is assumed that the ceramic oxide is formed by adhering to the outer surface of the ceramic and oxidizing it.

In the multilayer ceramic capacitor of the present invention, the strength of the outer surface of the ceramic body is increased, and cracks are suppressed from the ceramic body and external electrodes are suppressed from peeling from the ceramic body.

Further, according to the method for manufacturing a multilayer ceramic capacitor of the present invention, the multilayer ceramic capacitor of the present invention can be easily manufactured.

It is a perspective view of the multilayer ceramic capacitor 100 which concerns on 1st Embodiment. It is an exploded perspective view of the multilayer ceramic capacitor 100. It is sectional drawing of the multilayer ceramic capacitor 100. 4 (A) and 4 (B) are perspective views showing steps carried out in an example of a method for manufacturing the monolithic ceramic capacitor 100, respectively. 5 (C) and 5 (D) are continuations of FIG. 4 (B), and are perspective views showing steps performed in an example of a method for manufacturing the monolithic ceramic capacitor 100, respectively. It is a perspective view of the multilayer ceramic capacitor 200 which concerns on 2nd Embodiment. It is an exploded perspective view of the multilayer ceramic capacitor 200. It is a perspective view of the multilayer ceramic capacitor 300 which concerns on 3rd Embodiment. It is a perspective view of the multilayer ceramic capacitor 400 which concerns on 4th Embodiment. It is a perspective view of the multilayer ceramic capacitor 500 which concerns on 5th Embodiment. It is an exploded perspective view of the multilayer ceramic capacitor 500.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. It should be noted that each embodiment exemplifies the embodiment of the present invention, and the present invention is not limited to the content of the embodiment. It is also possible to combine the contents described in different embodiments, and the contents of the embodiment are also included in the present invention. In addition, the drawings are for the purpose of assisting the understanding of the specification, and may be drawn schematically, and the drawn components or the ratio of dimensions between the components are described in the specification. It may not match the ratio of those dimensions. In addition, the components described in the specification may be omitted in the drawings, or may be drawn by omitting the number of components.

[First Embodiment]
1 to 3 show the multilayer ceramic capacitor 100 according to the first embodiment. However, FIG. 1 is a perspective view of the monolithic ceramic capacitor 100. FIG. 2 is an exploded perspective view of the monolithic ceramic capacitor 100. FIG. 3 is a cross-sectional view of the monolithic ceramic capacitor 100, and shows the XX portion indicated by the alternate long and short dash arrow in FIG. The height direction T, the length direction L, and the width direction W of the multilayer ceramic capacitor 100 are shown in the drawing, and these directions may be referred to in the following description. However, in this embodiment, the stacking direction of the ceramic layers 1a and 1b, which will be described later, is defined as the height direction T of the multilayer ceramic capacitor 100.

The multilayer ceramic capacitor 100 includes a ceramic element 1 having a rectangular parallelepiped shape. The ceramic element 1 has a pair of main surfaces 1A and 1B facing each other in the height direction T and a pair of end faces 1C facing each other in the length direction L perpendicular to the height direction T as outer surfaces. It has a pair of side surfaces 1E and 1F facing each other in the width direction W orthogonal to both the height direction T and the length direction L.

The dimensions of the monolithic ceramic capacitor 100 are arbitrary. However, the dimension in the height direction T can be, for example, about 0.1 mm to 2.5 mm. The dimension of L in the length direction can be, for example, about 0.1 mm to 3.2 mm. The dimension of W in the width direction can be, for example, about 0.1 mm to 2.5 mm.

The ceramic element 1 is composed of a plurality of ceramic layers 1a and 1b and a plurality of internal electrodes 2 and 3 laminated. However, the ceramic layer 1a is a protective layer laminated on the lowermost layer and the uppermost layer of the ceramic element 1, respectively. The ceramic layer 1b is a ceramic layer in an effective region that exhibits capacitance and is laminated on top of the internal electrodes 2 and 3.

The thickness of the ceramic layer 1a, which is the protective layer, is arbitrary, but can be, for example, about 15 μm to 150 μm. The figure shows a state in which one ceramic layer 1a is laminated on the bottom layer and the top layer, respectively. The ceramic layer 1a has a plurality of layers on the bottom and top of the ceramic body 1, respectively. It may be laminated.

The thickness of the ceramic layer 1b in the effective region is arbitrary, but can be, for example, about 0.3 μm to 2.0 μm. The number of layers of the ceramic layer 1b is arbitrary, but can be, for example, 1 to 6000 layers.

The material of the ceramic element 1 (ceramic layers 1a and 1b) is arbitrary, but for example, _{dielectric ceramics containing Badio 3} as a main component can be used. However, instead of _{BaTiO 3} , dielectric ceramics containing other materials as main components, such as _{CaTIO 3} , SrTIO ₃ , and CaZrO _{3, may be used.} The material of the ceramic layer 1a of the protective layer may be different from the material of the ceramic layer 1b in the effective region.

Nickel oxide 4 is formed on the side surfaces 1E and 1F of the ceramic element 1, respectively. In the present embodiment, the nickel oxide 4 is formed in a rectangular shape at the central portion of each of the side surfaces 1E and 1F.

In this embodiment, the nickel oxide 4 is formed in a film shape. However, the state in which nickel oxide 4 is formed is arbitrary, and may be formed by being dispersed in dots instead of the film. Further, the shape of nickel oxide 4 is also arbitrary and is not limited to a rectangular shape.

Nickel oxide 4 is insulating. Therefore, there is no possibility that the nickel oxide 4 short-circuits the external electrode 5 and the external electrode 6, which will be described later. Nickel oxide 4 improves the strength of the outer surface of the ceramic element 1. The mechanism for improving the strength of the outer surface of the ceramic element 1 will be described later.

The internal electrode 2 is drawn out to the end face 1C of the ceramic element 1. The internal electrode 3 is drawn out to the end face 1D of the ceramic element 1.

In this embodiment, nickel is used as the material of the main components of the internal electrodes 2 and 3. However, the materials of the internal electrodes 2 and 3 may contain other metals in addition to nickel. Nickel may also be an alloy with other metals.

The thickness of the internal electrodes 2 and 3 is arbitrary, but can be, for example, about 0.3 μm to 1.5 μm.

A gap is formed between the internal electrodes 2 and 3 and the side surfaces 1E and 1F of the ceramic element 1. The gap size is arbitrary, but can be, for example, about 10 μm to 200 μm. The gap size between the internal electrode 3 and the end faces 1C and 1D of the ceramic element 1 is arbitrary, but can be, for example, about 0.5 μm to 300 μm.

External electrodes 5 and 6 are formed on the outer surface of the ceramic element 1.

The external electrode 5 is formed on the end face 1C of the ceramic element 1. The external electrode 5 is formed in a cap shape, and the edge portion is formed so as to extend from the end surface 1C of the ceramic element 1 to the main surfaces 1A, 1B, the side surfaces 1E, and 1F. The internal electrode 2 drawn out from the end surface 1C of the ceramic element 1 is connected to the external electrode 5.

The external electrode 6 is formed on the end face 1D of the ceramic element 1. The external electrode 6 is formed in a cap shape, and the edge portion is formed so as to extend from the end surface 1D of the ceramic element 1 to the main surfaces 1A, 1B, the side surfaces 1E, and 1F. The internal electrode 3 drawn out from the end surface 1D of the ceramic element 1 is connected to the external electrode 6.

In the present embodiment, the external electrodes 5 and 6 are each composed of a base electrode layer formed by baking a conductive paste and a plating layer formed on the base electrode layer. However, in FIG. 3, the external electrodes 5 and 6 are shown in one layer, respectively, in order to avoid obscuring the view.

The material of the main component of the base electrode layer is arbitrary, but for example, copper, nickel, silver, palladium, silver-palladium alloy, gold, or the like can be used. It is also preferable to include glass in the base electrode layer. In this case, the bonding strength of the base electrode layer with respect to the ceramic body can be improved. The thickness of the base electrode layer is arbitrary, but can be, for example, about 9 μm to 150 μm.

The material of the main component of the plating layer and the number of layers of the plating layer are arbitrary, but for example, the first layer can be formed into a two-layer structure of nickel and the second layer can be formed of tin. The thickness of each plating layer is also arbitrary, but can be, for example, about 0.1 μm to 4.0 μm. The nickel-plated layer mainly functions to improve solder heat resistance and adhesion. The tin-plated electrode layer mainly functions to improve solderability. The nickel-plated layer and the tin-plated layer may each contain impurities. Further, the nickel plating layer and the tin plating layer may be alloys with other metals, respectively.

The monolithic ceramic capacitor 100 according to the first embodiment can be manufactured by, for example, the manufacturing methods shown in FIGS. 4 (A) to 5 (D).

Although not shown, first, a powder of dielectric ceramics, a binder resin, a solvent, and the like are prepared, and these are wet-mixed to prepare a ceramic slurry.

Next, the ceramic slurry is applied onto the carrier film in the form of a sheet using a die coater, a gravure coater, a microgravure coater, or the like, and dried to prepare a ceramic green sheet.

Next, in order to form the internal electrodes 2 and 3 on the main surface of the predetermined ceramic green sheet, a conductive paste prepared in advance is applied (for example, printed) to a desired pattern shape. The conductive paste is not applied to the ceramic green sheet serving as the ceramic layer 1a, which is the protective layer. As the conductive paste, for example, a mixture of nickel powder, a binder resin, a solvent, or the like can be used.

Next, the ceramic green sheets are laminated in a predetermined order, heat-bonded and integrated to prepare an unfired ceramic body.

Next, the unfired ceramic body is fired with a predetermined profile. As a result, the ceramic green sheet is fired to form ceramic layers 1a and 1b, and the conductive paste applied to the main surface of the ceramic green sheet is fired at the same time to form internal electrodes 2 and 3, as shown in FIG. 4 (A). The ceramic element 1 shown is produced. The ceramic element 1 has a pair of main surfaces 1A and 1B, a pair of end surfaces 1C and 1D, and a pair of side surfaces 1E and 1F. In the ceramic body 1, the internal electrode 2 is drawn out from the end face 1C, and the internal electrode 3 is drawn out from the end face 1D.

Next, annealing is performed on the ceramic element 1. Annealing of the ceramic element 1 is carried out for the purpose of improving the quality.

First, as shown in FIG. 4B, a plurality of ceramic elements 1 are arranged in the box 17. In the present embodiment, the end surface 1C or 1D of the ceramic element 1 is brought into contact with the central portion of the side surface 1E or 1F of the other ceramic element 1, and the main surface 1A of the ceramic element 1 is brought into contact with the upper surface of the box 17. To abut. As a result, the internal electrode 2 or 3 drawn from the end surface 1C or 1D of the ceramic element 1 comes into contact with the central portion of the side surface 1E or 1F of the other ceramic element 1. The plurality of ceramic elements 1 may be arranged by using a jig such as an arrangement plate having a plate shape and a through hole formed therein. Alternatively, the arrangement of the plurality of ceramic elements 1 may be performed by computer control using a mounting device.

In the application documents, "opposing" the end face and the side surface means that the end face and the side surface face each other, and the case where the end face and the side surface "face each other with a gap" and the case where the end face and the side surface face each other. Including the case of "facing each other without a gap". The case where the end face and the side surface "face each other without a gap" is called "contact" between the end face and the side surface. However, even when the end face and the side surface are brought into contact with each other, a gap may be inevitably generated between the end face and the side surface due to vibration or the like. It shall be included in "to let".

Next, in the state shown in FIG. 4B, the plurality of ceramic elements 1 arranged in the box 17 are heated at a predetermined temperature for a predetermined time. In the present embodiment, as described above, at the time of annealing, the end surface 1C or 1D of the ceramic element 1 is brought into contact with the central portion of the side surface 1E or 1F of the other ceramic element 1. Alternatively, the end faces 1C or 1D of the ceramic element 1 may be opposed to the central portion of the side surfaces 1E or 1F of the other ceramic element 1 at intervals.

The annealing temperature and time are arbitrary and can be set as appropriate.

When the annealing is completed, as shown in FIG. 5C, nickel oxide 4 is formed into a film on the central portions of the side surfaces 1E and 1F of the ceramic element 1, respectively. The nickel oxide 4 is mainly composed of nickel separated from the internal electrode 2 or 3 drawn from the end surface 1C or 1D of the other ceramic element 1 which was in contact with the side surface 1E or 1F, and the nickel oxide is separated from the side surface 1E or 1F. It is formed by adhering to and oxidizing. The release of nickel from the internal electrodes 2 and 3 means that nickel evaporates or flows out from the internal electrodes 2 and 3.

The outer surface of the ceramic element 1 in the portion where the nickel oxide 4 is formed has higher strength than the other portions. This is because, at the time of annealing, the sintering of the ceramic in the portion where the nickel oxide 4 on the outer surface of the ceramic element 1 is formed proceeds more than the sintering of the ceramic in the other portion due to the nickel, and the ceramic in the portion concerned. It is thought that this is because it has become more precise.

Next, as shown in FIG. 5D, external electrodes 5 and 6 are formed at both ends of the ceramic element 1. First, a conductive paste is applied to both ends of the ceramic element 1. Specifically, both ends of the ceramic element 1 are immersed in a bath containing a conductive paste. Next, the ceramic element 1 coated with the conductive paste is heated at a predetermined temperature, and the conductive paste is baked to form a base electrode layer at both ends of the ceramic element 1. Next, a plating layer is formed on the base electrode layer, and external electrodes 5 and 6 are formed on both ends of the ceramic element 1.

From the above, the monolithic ceramic capacitor 100 is completed.

In the multilayer ceramic capacitor 100, the strength of the portion of the outer surface of the ceramic body 1 on which nickel oxide 4 is formed is high. In the multilayer ceramic capacitor 100, the main surfaces 1A and 1B of the ceramic element 1 are provided with a ceramic layer 1a as a protective layer having a large thickness, and have relatively high strength. On the other hand, the ends of the laminated ceramic layer 1b having a small thickness are exposed on the side surfaces 1E and 1F of the ceramic element 1 of the multilayer ceramic capacitor 100, and the strength is relatively low. Therefore, in the multilayer ceramic capacitor 100, nickel oxide 4 is formed on the side surfaces 1E and 1F of the ceramic element 1 to improve the strength. In the multilayer ceramic capacitor 100, the strengths of the side surfaces 1E and 1F of the ceramic element 1 are enhanced, and cracks are prevented from occurring in the ceramic element 1 and external electrodes 5 and 6 are suppressed from peeling from the ceramic element 1. Has been done.

[Second Embodiment]
6 and 7 show the multilayer ceramic capacitor 200 according to the second embodiment. However, FIG. 6 is a perspective view of the multilayer ceramic capacitor 200. FIG. 7 is an exploded perspective view of the multilayer ceramic capacitor 200.

The multilayer ceramic capacitor 200 according to the second embodiment is a modification of a part of the configuration of the multilayer ceramic capacitor 100 according to the first embodiment described above. Specifically, in the multilayer ceramic capacitor 100, nickel oxide 4 was formed on the central portions of the side surfaces 1E and 1F of the ceramic element 1. The multilayer ceramic capacitor 200 was modified to form nickel oxides 24a and 24b in a film shape by being divided into two at both ends of the side surfaces 1E and 1F of the ceramic element 1 in the length direction L. Other configurations of the monolithic ceramic capacitor 200 were the same as those of the monolithic ceramic capacitor 100.

FIG. 4B shows the arrangement of the plurality of ceramic elements 1 on the box 17 when annealing the multilayer ceramic capacitor 200 in the method for manufacturing the multilayer ceramic capacitor 100 of the first embodiment described above. It can be manufactured by changing from.

In the multilayer ceramic capacitor 200, nickel oxides 24a and 24b are formed on the portions where the external electrodes 5 and 6 of the side surfaces 1E and 1F of the ceramic element 1 are formed, and the strength of the portions of the ceramic element 1 is enhanced. ing. In general, cracks in the ceramic element of a multilayer ceramic capacitor often occur starting from the edge of an external electrode. Further, in general, peeling of the external electrode of the monolithic ceramic capacitor often occurs starting from the edge of the external electrode. In the multilayer ceramic capacitor 200, nickel oxides 24a and 24b are formed on the portions of the side surfaces 1E and 1F of the ceramic element 1 on which the external electrodes 5 and 6 are formed to increase the strength of the portions. The occurrence of cracks in 1 and the peeling of the external electrode from the ceramic body are further suppressed.

[Third Embodiment]
FIG. 8 shows the multilayer ceramic capacitor 300 according to the third embodiment. However, FIG. 8 is a perspective view of the multilayer ceramic capacitor 300.

The multilayer ceramic capacitor 300 according to the third embodiment is a modification of a part of the configuration of the multilayer ceramic capacitor 100 according to the first embodiment described above. Specifically, in the multilayer ceramic capacitor 100, nickel oxide 4 was formed on the central portions of the side surfaces 1E and 1F of the ceramic element 1. The multilayer ceramic capacitor 300 was modified to form nickel oxide 34 in the form of a film on the entire surfaces of the side surfaces 1E and 1F of the ceramic element 1. Other configurations of the monolithic ceramic capacitor 200 were the same as those of the monolithic ceramic capacitor 100.

The strength of the multilayer ceramic capacitor 300 is increased on the entire surfaces 1E and 1F of the side surfaces 1E and 1F of the ceramic element 1, so that the ceramic element 1 is cracked and the external electrodes 5 and 6 are peeled off from the ceramic element 1. Is suppressed.

[Fourth Embodiment]
FIG. 9 shows the multilayer ceramic capacitor 400 according to the fourth embodiment. However, FIG. 9 is a perspective view of the multilayer ceramic capacitor 400.

The multilayer ceramic capacitor 400 according to the fourth embodiment is a modification of a part of the configuration of the multilayer ceramic capacitor 300 according to the third embodiment described above. Specifically, in the multilayer ceramic capacitor 300, nickel oxide 34 was formed on the side surfaces 1E and 1F of the ceramic element 1. The multilayer ceramic capacitor 400 was modified to form nickel oxide 44 in the form of a film on the entire surfaces of the main surfaces 1A and 1B of the ceramic element 1. Other configurations of the multilayer ceramic capacitor 400 were the same as those of the multilayer ceramic capacitor 300.

In the multilayer ceramic capacitor 400, the strength of the main surfaces 1A and 1B of the ceramic element 1 is increased, cracks may occur in the ceramic element 1, and the external electrodes 5 and 6 may be peeled off from the ceramic element 1. It is suppressed.

[Fifth Embodiment]
10 and 11 show the multilayer ceramic capacitor 500 according to the fifth embodiment. However, FIG. 10 is a perspective view of the multilayer ceramic capacitor 500. FIG. 11 is an exploded perspective view of the multilayer ceramic capacitor 500.

The multilayer ceramic capacitor 500 according to the fifth embodiment is a modification of a part of the configuration of the multilayer ceramic capacitor 100 according to the first embodiment described above. Specifically, in the multilayer ceramic capacitor 100, the ends of the laminated ceramic layers 1a and 1b were exposed on the side surfaces 1E and 1F of the ceramic element 1. Further, in the multilayer ceramic capacitor 100, the internal electrodes 2 and 3 were not exposed on the side surfaces 1E and 1F of the ceramic element 1. The multilayer ceramic capacitor 500 was modified to expose the internal electrodes 52 and 53 from the side surfaces of the laminated ceramic layers 1a and 1b. Then, the side ceramic layers 51c were formed on the side surfaces of the ceramic layers 1a and 1b where the internal electrodes 52 and 53 were exposed. Then, the side surface ceramic layer 51c was designated as the side surfaces 51E and 51F of the ceramic body 51.

In the multilayer ceramic capacitor 500, nickel oxide 34 was formed into a film on the central portions of the side surfaces 51E and 51F of the ceramic body 51 composed of the side ceramic layer 51c. Other configurations of the multilayer ceramic capacitor 500 were the same as those of the multilayer ceramic capacitor 100.

The multilayer ceramic capacitor 500 is provided on the side surface of the laminated ceramic green sheet after the ceramic green sheets are laminated in the step of producing the unfired ceramic element of the method for manufacturing the laminated ceramic capacitor 100 of the first embodiment described above. It can be manufactured by attaching a side ceramic green sheet.

In the multilayer ceramic capacitor 500, the strength of the side surfaces 51E and 51F of the ceramic body 51 is increased, and cracks are prevented from occurring in the ceramic body 51 and external electrodes 5 and 6 are suppressed from peeling from the ceramic body 51. Has been done.

Further, since the laminated ceramic capacitor 500 exposes the internal electrodes 52 and 53 from the side surfaces of the laminated ceramic layers 1a and 1b, the area of the internal electrodes 52 and 53 should be larger than that of the laminated ceramic capacitor 100. It is possible to increase the capacitance.

The multilayer ceramic capacitors 100, 200, 300, 400, and 500 according to the first to fifth embodiments have been described above. However, the present invention is not limited to the above-mentioned contents, and various modifications can be made in accordance with the gist of the invention.

For example, in the method for manufacturing the monolithic ceramic capacitor 100 described above, the arrangement of the plurality of ceramic elements 1 in the box 17 when annealing the ceramic element 1 shown in FIG. 4B is an example, and changes are made. can do. By changing the arrangement of the plurality of ceramic elements 1 in the box 17, the position of the nickel oxide 4 in the ceramic element 1 can be changed.

Further, in the method for manufacturing the multilayer ceramic capacitor 100 described above, in the step of annealing the ceramic element 1, the end surface 1C or 1D of the ceramic element 1 is brought into contact with the side surface 1E or 1F of the other ceramic element 1. However, this may be changed so that the end surface 1C or 1D of the ceramic element 1 faces the side surface 1E or 1F of the other ceramic element 1 at intervals. Also in this case, nickel evaporated (separated) from the internal electrode 2 or 3 drawn from the end face 1C or 1D of the ceramic element 1 adheres to the outer surface of the other ceramic element 1 and is oxidized to be oxidized. Nickel 4 is formed.

Further, in the above-described embodiment, nickel oxides 4, 24a, 24b, 34, 44, and 54 are formed on the side surfaces or main surfaces of the ceramic elements 1, 51, but nickel oxide is formed on the side surfaces and the main surface of the ceramic elements. It may be formed on both main surfaces. Further, nickel oxide may be attached (or may be formed) to a portion of the outer surface of the ceramic elements 1 and 51 other than the portions where nickel oxides 4, 24a, 24b, 34, 44, and 54 are formed. ).

The monolithic ceramic capacitor according to an embodiment of the present invention is as described in the column of "Means for Solving Problems".

In this multilayer ceramic capacitor, it is also preferable that nickel oxide is formed in a film shape on the outer surface of the ceramic element body. In this case, the strength of the portion where nickel oxide is formed into a film on the outer surface of the ceramic element is improved.

A part of the internal electrode is drawn from one end face of the ceramic body and electrically connected to the external electrode, and the rest of the internal electrode is pulled out from the other end face of the ceramic body and electrically connected to the external electrode. It is also preferable to be connected. In this case, a two-terminal multilayer ceramic capacitor can be obtained. However, the multilayer ceramic capacitor of the present invention is not limited to two terminals, and may be a multilayer ceramic capacitor having another structure such as three terminals.

The ceramic body may have nickel oxide on at least a part of the side surface. In this case, it is also preferable that at least a part of the external electrode is formed on the side surface and nickel oxide is provided between the side surface of the ceramic body and the external electrode. In this case, peeling of the external electrode from the ceramic body can be effectively suppressed. Further, cracks originating from the edge of the external electrode can be effectively suppressed.

The ceramic element may have nickel oxide on at least a part of the main surface. In this case, it is also preferable that at least a part of the external electrode is formed on the main surface, and nickel oxide is provided between the main surface of the ceramic element and the external electrode. In this case, peeling of the external electrode from the ceramic body can be effectively suppressed. Further, cracks originating from the edge of the external electrode can be effectively suppressed.

It is also preferable that the ceramic body includes a side ceramic layer formed on the side surface. In this case, since it is not necessary to form gaps on both sides of the internal electrode in the width direction, the area of the internal electrode can be increased and the capacitance can be increased.

The method for manufacturing a multilayer ceramic capacitor according to an embodiment of the present invention is as described in the column of "Means for Solving Problems".

In this method for manufacturing a multilayer ceramic capacitor, it is also preferable that nickel oxide is formed into a film on the outer surface of the ceramic element. In this case, the strength of the portion where nickel oxide is formed into a film on the outer surface of the ceramic element is improved.

Further, in the step of drawing out a part of the internal electrode from one end face of the ceramic element body and drawing out the rest of the internal electrode from the other end face of the ceramic element body and annealing the ceramic element body, one ceramic element. It is also preferable that at least one end face of the body faces the side surface or main surface of the other ceramic element. In this case, nickel oxide can be easily formed on the side surface or the main surface of the other ceramic element. Further, in this case, in the step of annealing the ceramic element, it is also preferable that at least one end surface of one ceramic element is brought into contact with the side surface or the main surface of the other ceramic element. In this case, nickel oxide can be more easily formed on the side surface or the main surface of the other ceramic element.

In the process of laminating and integrating a plurality of ceramic green sheets to produce an unfired ceramic element, after laminating a plurality of ceramic green sheets, side surface ceramic greens are placed on the side surfaces of the laminated ceramic green sheets. It is also preferable to further include a step of attaching the sheet. In this case, the side ceramic layer can be formed on the ceramic body, and it is not necessary to form gaps on both sides in the width direction of the internal electrode, so that the area of the internal electrode can be increased and the area of the internal electrode can be increased. It is possible to increase the electric capacity.

1, 51 ... Ceramic elements 1a, 1b ... Ceramic layers 1A, 1B, 51A, 51B ... Main surfaces 1C, 1D, 51C, 51D ... End faces 1E, 1F, 51E, 51F ... Side surface 51c ... Side ceramic layers 2, 3, 52, 53 ... Internal electrodes 4, 24a, 24b, 34, 44, 54 ... Nickel oxide 5, 6 ... External electrodes 17 ... Box

Claims (13)

As outer surfaces, a pair of main surfaces facing each other in the height direction, a pair of end faces facing each other in the length direction orthogonal to the height direction, and the height direction and the length direction. A ceramic element body in which a plurality of ceramic layers and a plurality of internal electrodes are laminated, which has a pair of side surfaces facing each other in the orthogonal width directions.
A monolithic ceramic capacitor comprising at least two external electrodes formed on the outer surface of the ceramic body and electrically connected to the internal electrodes.
The internal electrode contains nickel as a component and contains nickel.
The ceramic body comprises nickel oxide on at least a part of the outer surface.
Multilayer ceramic capacitors. The nickel oxide was formed on the outer surface in the form of a film.
The multilayer ceramic capacitor according to claim 1. A part of the internal electrode is drawn from the end face of one of the ceramic elements and electrically connected to the external electrode.
The rest of the internal electrode was drawn from the other end face of the ceramic body and electrically connected to the external electrode.
The multilayer ceramic capacitor according to claim 1 or 2. The ceramic body includes the nickel oxide on at least a part of the side surface.
The multilayer ceramic capacitor according to any one of claims 1 to 3. At least a part of the external electrode is formed on the side surface.
The nickel oxide is provided between the side surface of the ceramic body and the external electrode.
The multilayer ceramic capacitor according to claim 4. The ceramic body includes the nickel oxide on at least a part of the main surface.
The multilayer ceramic capacitor according to any one of claims 1 to 5. At least a part of the external electrode is formed on the main surface,
The nickel oxide is provided between the main surface of the ceramic body and the external electrode.
The multilayer ceramic capacitor according to claim 6. The ceramic body includes a side ceramic layer formed on the side surface.
The multilayer ceramic capacitor according to any one of claims 1 to 7. The process of making a ceramic green sheet and
A step of applying a conductive paste for forming an internal electrode to the main surface of the ceramic green sheet in a desired shape, if necessary, and a step of applying the conductive paste to a desired shape.
A process of laminating and integrating a plurality of the ceramic green sheets to prepare an unfired ceramic element body, and
The unfired ceramic element is fired, and as the outer surface, a pair of main surfaces facing each other in the height direction and a pair of end faces facing each other in the length direction orthogonal to the height direction are used. It has a pair of side surfaces facing each other in the width direction orthogonal to the height direction and the length direction, a plurality of ceramic layers and a plurality of internal electrodes are laminated, and the internal electrodes are outside the outer electrode. The process of producing the ceramic element drawn out on the surface and
The step of heating and annealing the ceramic body and
A method for manufacturing a multilayer ceramic capacitor, comprising a step of forming an external electrode electrically connected to the internal electrode on the outer surface of the ceramic body.
When the conductive paste contains nickel as a component, the internal electrode contains nickel as a component.
In the step of annealing the ceramic element, a part of the nickel contained in the component is separated from the internal electrode of the ceramic element, and the outer surface of the other ceramic element and / or the ceramic. It adheres to the outer surface of the element body and is oxidized to form nickel oxide.
Manufacturing method of multilayer ceramic capacitors. The nickel oxide is formed on the outer surface in the form of a film.
The method for manufacturing a multilayer ceramic capacitor according to claim 9. A part of the internal electrode is pulled out from the end face of one of the ceramic elements.
The rest of the internal electrode is drawn from the other end face of the ceramic body and
In the step of annealing the ceramic body,
At least one end face of one ceramic element is opposed to the side surface or main surface of the other ceramic element.
The method for manufacturing a multilayer ceramic capacitor according to claim 9 or 10. In the step of annealing the ceramic body,
The end face of at least one of the ceramic elements is brought into contact with the side surface or the main surface of the other ceramic element.
The method for manufacturing a multilayer ceramic capacitor according to claim 11. In the step of laminating and integrating a plurality of the ceramic green sheets to prepare an unfired ceramic element body.
After laminating the plurality of ceramic green sheets, a step of attaching the side ceramic green sheets to the side surfaces of the laminated ceramic green sheets is further provided.
The method for manufacturing a multilayer ceramic capacitor according to any one of claims 9 to 12.

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