JP2020188081A - Multilayer ceramic electronic component - Google Patents

Abstract

To provide a multilayer ceramic electronic component that can prevent short-circuit failure and migration from occurring while preventing peeling from occurring on a boundary surface between an internal electrode layer and a ceramic layer.SOLUTION: A multilayer ceramic capacitor 10 according to the present invention includes a rectangular parallelepiped multilayered body 12. First and second external electrodes 24a and 24b are provided on both end surfaces of the multilayered body. A metal layer 30 is arranged on first and second main surfaces and first and second side surfaces of the multilayered body so as to circle around the multilayered body 12. Furthermore, a protective layer 32 is arranged on the first and second main surfaces and the first and second side surfaces of the multilayered body 12 located between the first and second external electrodes 24a and 24b so as to cover the metal layer 30.SELECTED DRAWING: Figure 1

Description

The present invention relates to laminated ceramic electronic components.

Generally, a laminated ceramic electronic component includes a laminated body in which internal electrode layers and ceramic layers are alternately laminated, and an external electrode provided on the outer surface of the laminated body. For example, in the case of a laminated ceramic capacitor. If so, the ceramic layer is made of a ceramic dielectric material (see, for example, Patent Document 1).

Here, the ceramic dielectric material and the metal of the internal electrode layer are difficult to adhere to each other because the materials of the internal electrode layer and the ceramic dielectric material are completely different, and the thermal expansion coefficient between the internal electrode layer and the ceramic layer is large. Since they are different, the strain becomes large due to the difference in the amount of shrinkage between the internal electrode layer and the ceramic layer due to the temperature change. Therefore, it is generally known that problems such as peeling occur at the interface between the internal electrode layer and the ceramic layer.

In response to the above problems, when the external electrodes are formed so as to go around the four sides of the laminated body, the external electrode paste is heat-shrinked when it is dried and baked. It has the effect of alleviating problems.
Therefore, in order to further increase the above effect, for example, the distance between the first external electrode and the second external electrode formed on the four side surfaces of the laminated body is made as small as possible to increase the area where the external electrode is formed. It is possible to increase it.

Japanese Unexamined Patent Publication No. 8-306580

However, by making the distance between the first external electrode and the second external electrode formed on the four side surfaces of the laminated body as small as possible and increasing the area formed by the external electrodes, the lamination is performed. Although the tightening effect of the body is increased, there is a concern that problems such as short circuit failure and migration may occur when the distance between the first external electrode and the second external electrode becomes short.

Therefore, a main object of the present invention is to provide a laminated ceramic electronic component capable of suppressing the occurrence of short-circuit defects and migration while suppressing the occurrence of peeling and the like at the interface between the internal electrode layer and the ceramic layer. Is.

The laminated ceramic electronic component according to the present invention includes a plurality of laminated ceramic layers and a plurality of internal electrode layers laminated on the ceramic layers, and has a first main surface and a second main surface facing each other in the height direction. The main surface, the first side surface and the second side surface facing the width direction orthogonal to the height direction, and the first end face and the second end face facing the length direction orthogonal to the height direction and the width direction. And on the first end face, as well as part of the first main surface, part of the second main surface, part of the first side surface, and part of the second side surface. A first external electrode to be arranged, on the second end face, and a part of the first main surface, a part of the second main surface, a part of the first side surface, and one of the second side surfaces. A second external electrode arranged in the portion is provided, and the laminated body is orbited on the first main surface, the second main surface, the first side surface, and the second side surface of the laminated body. On the first main surface, on the second main surface, on the first side surface and on the first surface of the laminate having the metal layer to be arranged and located between the first external electrode and the second external electrode. It is a laminated ceramic electronic component having a protective layer arranged on the side surface of 2 and arranged so as to cover the metal layer.

In the laminated ceramic electronic component according to the present invention, a metal layer is arranged so as to orbit the laminated body on the first main surface, the second main surface, the first side surface, and the second side surface of the laminated body. Therefore, in the central part of the laminated body, the product body is tightened by the heat shrinkage of the metal layer paste when forming the metal layer, so that the effect of reducing the residual stress can be exerted and the layer peeling can be suppressed. it can. Further, it is arranged on the first main surface, the second main surface, the first side surface, and the second side surface of the laminate located between the first external electrode and the second external electrode. Since it has a protective layer arranged so as to cover the metal layer, the external electrode formed on the laminated body and the metal layer can be covered with a non-conductive protective layer, so that short-circuit defects and migration between the external electrodes can occur. It is possible to prevent such occurrences.

According to the present invention, it is possible to obtain a laminated ceramic electronic component capable of suppressing the occurrence of peeling or the like at the interface between the internal electrode layer and the ceramic layer, and also suppressing the occurrence of short circuit defects or migration.

The above-mentioned object, other object, feature and advantage of the present invention will be further clarified from the description of the embodiments for carrying out the following invention with reference to the drawings.

It is an external perspective view which shows an example of the multilayer ceramic capacitor which concerns on embodiment of this invention. It is a side view of FIG. 1 which shows the multilayer ceramic capacitor which concerns on embodiment of this invention. It is sectional drawing in line III-III of FIG. 1 which shows the multilayer ceramic capacitor which concerns on this invention. It is sectional drawing in line IV-IV of FIG. 3 which shows the multilayer ceramic capacitor which concerns on this invention. It is sectional drawing in line VV of FIG. 3 which shows the multilayer ceramic capacitor which concerns on this invention. (A) is a cross-sectional view taken along the line III-III of FIG. 1 showing a structure in which the counter electrode portion of the internal electrode layer of the multilayer ceramic capacitor according to the present invention is divided into two, and (b) the laminated ceramic according to the present invention. It is sectional drawing in line III-III of FIG. 1 which shows the structure which the counter electrode part of the internal electrode layer of a capacitor is divided into three, (c) the counter electrode part of the internal electrode layer of the multilayer ceramic capacitor which concerns on this invention. It is sectional drawing in line III-III of FIG. 1 which shows the structure which is divided into four. It is an external perspective view which shows an example of the modification of the multilayer ceramic capacitor which concerns on embodiment of this invention. It is a side view of FIG. 7 which shows the multilayer ceramic capacitor which concerns on embodiment of this invention. It is sectional drawing in the line IX-IX of FIG. 7 which shows the multilayer ceramic capacitor which concerns on embodiment of this invention. It is sectional drawing in line XX of FIG. 9 which shows the multilayer ceramic capacitor which concerns on embodiment of this invention. 9 is a cross-sectional view taken along the line XI-XI of FIG. 9 showing a multilayer ceramic capacitor according to an embodiment of the present invention.

1. 1. Multilayer Ceramic Electronic Components As an example of the multilayer ceramic electronic components of the present invention, a monolithic ceramic capacitor will be described. FIG. 1 is an external perspective view showing an example of a multilayer ceramic capacitor according to the present invention. FIG. 2 is a side view of FIG. 1 showing a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 1 showing the multilayer ceramic capacitor according to the present invention, and FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3 showing the multilayer ceramic capacitor according to the present invention. is there. FIG. 5 is a cross-sectional view taken along the line VV of FIG. 3 showing a monolithic ceramic capacitor according to the present invention.

As shown in FIGS. 1 to 5, the multilayer ceramic capacitor 10 includes a rectangular parallelepiped laminated body 12.

The laminated body 12 has a plurality of laminated ceramic layers 14 and a plurality of internal electrode layers 16. Further, the laminated body 12 has a first main surface 12a and a second main surface 12b facing the height direction x, and a first side surface 12c and a second side surface 12c facing the width direction y orthogonal to the height direction x. 12d, and has a first end face 12e and a second end face 12f facing the length direction z orthogonal to the height direction x and the width direction y. It is preferable that the laminated body 12 has rounded corners and ridges. The corner portion is a portion where three adjacent surfaces of the laminated body intersect, and the ridge portion is a portion where two adjacent surfaces of the laminated body intersect. Further, unevenness or the like is formed on a part or all of the first main surface 12a and the second main surface 12b, the first side surface 12c and the second side surface 12d, and the first end surface 12e and the second end surface 12f. It may have been. Further, the dimension of the laminated body 12 in the length direction z is not always longer than the dimension in the width direction y.

The number of ceramic layers 14 including the outer layer is preferably 10 or more and 1000 or less.

The laminate 12 includes an outer layer portion 15a composed of a plurality of ceramic layers 14 and an inner layer portion 15b composed of a single or a plurality of ceramic layers 14 and a plurality of internal electrode layers 16 arranged on the ceramic layers 14. including. The outer layer portion 15a is located on the first main surface 12a side and the second main surface 12b side of the laminated body 12, and is formed by the first main surface 12a and the inner electrode layer 16 closest to the first main surface 12a. It is an aggregate of a plurality of ceramic layers 14 located between the ceramic layers 14 and a plurality of ceramic layers 14 located between the second main surface 12b and the internal electrode layer 16 closest to the second main surface 12b. The region sandwiched between the two outer layer portions 15a is the inner layer portion 15b. The thickness of the outer layer portion 15a is preferably 15 μm or more and 400 μm or less.

The dimensions of the laminated body 12 are not particularly limited, but the dimensions in the length direction z are 1.0 mm or more and 7.0 mm or less, the dimensions in the width direction y are 0.5 mm or more and 6.0 mm or less, and the height direction x. The dimensions are preferably 0.5 mm or more and 6.0 mm or less.

The ceramic layer 14 can be formed of, for example, a dielectric material. Examples of such a dielectric material, for example, can be used a dielectric ceramic containing a component such as BaTiO _3, CaTiO _3, SrTiO ₃ or CaZrO _3,. When the above-mentioned dielectric material is contained as a main component, the sub-content is smaller than that of the main components such as Mn compound, Fe compound, Cr compound, Co compound and Ni compound, depending on the desired characteristics of the laminate 12. Those to which the component is added may be used.

When piezoelectric ceramic is used for the laminated body 12, the laminated ceramic electronic component functions as a ceramic piezoelectric element. Specific examples of the piezoelectric ceramic material include PZT (lead zirconate titanate) ceramic materials.
When a semiconductor ceramic is used for the laminated body 12, the laminated ceramic electronic component functions as a thermistor element. Specific examples of the semiconductor ceramic material include spinel-based ceramic materials.
Further, when magnetic ceramic is used for the laminated body 12, the laminated ceramic electronic component functions as an inductor element. Further, when functioning as an inductor element, the internal electrode layer 16 becomes a coil-shaped conductor. Specific examples of the magnetic ceramic material include a ferrite ceramic material.

The thickness of the ceramic layer 14 after firing is preferably 0.6 μm or more and 30.0 μm or less.

The laminate 12 has, for example, a plurality of substantially rectangular first internal electrode layers 16a and a plurality of second internal electrode layers 16b as the plurality of internal electrode layers 16. The plurality of first internal electrode layers 16a and the plurality of second internal electrode layers 16b are embedded so as to be alternately arranged at equal intervals along the height direction x of the laminated body 12. The first internal electrode layer 16a and the second internal electrode layer 16b may be arranged so as to be parallel to the mounting surface, or may be arranged so as to be perpendicular to the mounting surface.

The first internal electrode layer 16a is located on one end side of the first counter electrode portion 18a facing the second internal electrode layer 16b and the first internal electrode layer 16a, and is a laminate 12 from one counter electrode portion 18a. It has a first extraction electrode portion 20a up to the first end surface 12e of the above. The end portion of the first extraction electrode portion 20a is drawn out to the first end surface 12e and is exposed.
The second internal electrode layer 16b is located on one end side of the second counter electrode portion 18b facing the first internal electrode layer 16a and the second internal electrode layer 16b, and is from the second counter electrode portion 18b. It has a second lead-out electrode portion 20b up to the second end surface 12f of the laminated body 12. The end of the second lead-out electrode portion 20b is pulled out to the second end face 12f and is exposed.

The shape of one counter electrode portion 18a of the first internal electrode layer 16a and the other counter electrode portion 18b of the first internal electrode layer 16b is not particularly limited, but is preferably rectangular. However, the corners may be rounded or the corners may be formed diagonally (tapered).
The shapes of the first extraction electrode portion 20a of the first internal electrode layer 16a and the second extraction electrode portion 20b of the second internal electrode layer 16b are not particularly limited, but are preferably rectangular. However, the corners may be rounded or the corners may be formed diagonally (tapered).
The width of the first counter electrode portion 18a of the first internal electrode layer 16a and the width of the first extraction electrode portion 20a of the first internal electrode layer 16a may be formed to be the same width, whichever is used. One may be formed narrowly. Similarly, the width of the second counter electrode portion 18b of the second internal electrode layer 16b and the width of the second lead electrode portion 20b of the second internal electrode layer 16b may be formed to be the same width. , Either one may be formed narrowly.

The laminated body 12 is formed between one end of the first counter electrode portion 18a and the second counter electrode portion 18b in the width direction y and the first side surface 12c, and the first counter electrode portion 18a and the second counter electrode portion. The side portion (W gap) 22a of the laminated body 12 formed between the other end of the width direction y of 18b and the second side surface 12d is included. Further, the laminated body 12 is formed between the end portion of the first internal electrode layer 16a opposite to the first extraction electrode portion 20a and the second end surface 12f and the second of the second internal electrode layer 16b. The end portion (L gap) 22b of the laminated body 12 formed between the end portion on the side opposite to the extraction electrode portion 20b and the first end surface 12e is included.

The internal electrode layer 16 contains, for example, metals such as Ni, Cu, Ag, Pd, Au, and one of these metals, for example, an alloy containing at least one of these metals, such as an Ag—Pd alloy. Contains an appropriate conductive material. Internal electrode layer 16 Further, dielectric particles having the same composition as the ceramics contained in the ceramic layer 14 may be contained.

The thickness of the internal electrode layer 16 is preferably 0.1 μm or more and 2.0 μm or less. The number of internal electrode layers 16 is preferably 10 or more and 1000 or less.

External electrodes 24 are arranged on the first end face 12e side and the second end face 12f side of the laminated body 12. The external electrode 24 has a first external electrode 24a and a second external electrode 24b.
The first external electrode 24a is arranged on the surface of the first end surface 12e of the laminated body 12, extends from the first end surface 12e, and extends from the first main surface 12a, the second main surface 12b, and the first side surface. It is formed so as to cover each part of 12c and the second side surface 12d. In this case, the first external electrode 24a is electrically connected to the first extraction electrode portion 18a of the first internal electrode layer 16a. Here, the first external electrode 24a is on the first end surface 12e, and a part of the first main surface 12a, a part of the second main surface 12b, a part of the first side surface 12c, and It is arranged on a part of the second side surface 12d and covers the periphery of the laminated body 12, so that the residual stress is reduced by tightening the laminated body 12 by heat shrinkage of the external electrode paste at the time of firing the external electrode. It exerts the effect of making it. The first external electrode 24a may be formed only on the first end surface 12e of the laminated body 12.

The second external electrode 24b is arranged on the surface of the second end surface 12f of the laminated body 12, extends from the second end surface 12f, and extends from the first main surface 12a, the second main surface 12b, and the first side surface. It is formed so as to cover each part of 12c and the second side surface 12d. In this case, the second external electrode 24b is electrically connected to the second extraction electrode portion 18b of the second internal electrode layer 16b. Here, the second external electrode 24b is on the second end surface 12f, and a part of the first main surface 12a, a part of the second main surface 12b, a part of the first side surface 12c, and It is arranged on a part of the second side surface 12d and covers the periphery of the laminated body 12, so that the residual stress is reduced by tightening the laminated body 12 by heat shrinkage of the external electrode paste at the time of firing the external electrode. It exerts the effect of making it. The second external electrode 24b may be formed only on the second end surface 12f of the laminated body 12.

In the laminated body 12, the first counter electrode portion 18a of the first internal electrode layer 16a and the second counter electrode portion 18b of the second internal electrode layer 16b face each other via the ceramic layer 14. , Capacitance is formed. Therefore, a capacitance can be obtained between the first external electrode 24a to which the first internal electrode layer 16a is connected and the second external electrode 24b to which the second internal electrode layer 16b is connected. , The characteristics of the capacitor are expressed.

As shown in FIG. 6, the internal electrode layer 16 is pulled by both the first end surface 12e and the second end surface 12f in addition to the first internal electrode layer 16a and the second internal electrode layer 16b. A floating internal electrode layer 16c that is not exposed may be provided, and the counter electrode portion 18c may be divided into a plurality of structures by the floating internal electrode layer 16c. For example, it may have a double structure as shown in FIG. 6 (a), a triple structure as shown in FIG. 6 (b), or a quadruple structure as shown in FIG. Needless to say. In this way, by forming the counter electrode portion 18c into a plurality of divided structures, a plurality of capacitor components are formed between the opposing internal electrode layers 16a, 16b, 16c, and these capacitor components are connected in series. It becomes a composition. Therefore, the voltage applied to each capacitor component becomes low, and the withstand voltage of the multilayer ceramic capacitor can be increased.

As shown in FIG. 3, the first external electrode 24a includes the first base electrode layer 26a and the first plating layer 28a arranged on the surfaces of the first base electrode layer 26a in this order from the laminated body 12 side. Has. Similarly, the second external electrode 24b has a second base electrode layer 26b and a second plating layer 28b arranged on the surface of the second base electrode layer 26b in order from the laminated body 12 side.

The first base electrode layer 26a is arranged on the surface of the first end surface 12e of the laminated body 12, extends from the first end surface 12e, and extends from the first main surface 12a, the second main surface 12b, and the first. It is formed so as to cover a part of each of the side surface 12c and the second side surface 12d.
The second base electrode layer 26b is arranged on the surface of the second end surface 12f of the laminated body 12, extends from the second end surface 12f, and extends from the first main surface 12a, the second main surface 12b, and the first. It is formed so as to cover a part of each of the side surface 12c and the second side surface 12d.

The first base electrode layer 26a may be arranged only on the surface of the first end surface 12e of the laminated body 12, and the second base electrode layer 26b may be arranged on the second end surface 12f of the laminated body 12. It may be placed only on the surface.

The first base electrode layer 26a and the second base electrode layer 26b (hereinafter, also simply referred to as a base electrode layer) include at least one selected from a baking layer, a conductive resin layer, a thin film layer, and the like, respectively.

First, the first base electrode layer 26a and the second base electrode layer 26b in which the base electrode layer is formed by the baking layer will be described.
The baking layer contains glass and metal. The metal of the baking layer contains, for example, at least one selected from Cu, Ni, Ag, Pd, Ag—Pd alloy, Au and the like. Further, the glass of the baking layer contains at least one selected from B, Si, Ba, Mg, Al, Li and the like. The baking layer may be a plurality of layers. The baking layer is obtained by applying a conductive paste containing glass and metal to the laminate 12 and baking it, and may be baked at the same time as the ceramic layer 14 and the internal electrode layer 16, and the ceramic layer 14 and the internal electrode layer 16 may be baked. It may be baked after firing.

The thickness of each of the baked layers at the center in the height direction of the first base electrode layer 26a located on the first end surface 12e and the second base electrode layer 26b located on the second end face 12f is 10 μm or more and 50 μm or less. Is preferable.

Next, the first base electrode layer 26a and the second base electrode layer 26b in which the base electrode layer is formed of the conductive resin layer will be described.
The conductive resin layer may be arranged on the surface of the baking layer so as to cover the baking layer, or may be arranged directly on the surface of the laminate 12.
The conductive resin layer contains a thermosetting resin and a metal. Since the conductive resin layer contains a thermosetting resin, it is more flexible than, for example, a conductive layer made of a plating film or a fired product of a conductive paste. Therefore, even when a physical impact or an impact due to a thermal cycle is applied to the multilayer ceramic capacitor, the conductive resin layer functions as a buffer layer, and cracks in the multilayer ceramic capacitor can be prevented. ..

As the metal contained in the conductive resin layer, Ag, Cu, or an alloy thereof can be used. Further, a metal powder having an Ag coating on the surface can be used. When an Ag-coated metal powder is used, it is preferable to use Cu or Ni as the metal powder. Further, it is also possible to use Cu which has been subjected to an antioxidant treatment. In particular, using the conductive metal powder of Ag as the metal contained in the conductive resin layer is suitable as an electrode material because Ag has the lowest resistivity among the metals, and Ag is a noble metal and does not oxidize. It is preferable because of its high weather resistance. It is preferable to use an Ag-coated metal as the metal contained in the conductive resin layer because it is possible to reduce the cost of the base metal while maintaining the above-mentioned Ag characteristics.
The metal contained in the conductive resin layer is preferably contained in an amount of 35 vol% or more and 75 vol% or less with respect to the total volume of the conductive resin.
The shape of the metal (conductive filler) contained in the conductive resin layer is not particularly limited. As the conductive filler, a spherical one or a flat one can be used, but it is preferable to use a mixture of the spherical metal powder and the flat metal powder.
The average particle size of the metal (conductive filler) contained in the conductive resin layer is not particularly limited. The average particle size of the conductive filler may be, for example, about 0.3 μm or more and 10 μm or less.
The metal (conductive filler) contained in the conductive resin layer mainly bears the electrical conductivity of the conductive resin layer. Specifically, when the conductive fillers come into contact with each other, an energization path is formed inside the conductive resin layer.

As the resin of the conductive resin layer, for example, various known thermosetting resins such as epoxy resin, phenol resin, urethane resin, silicone resin, and polyimide resin can be used. Among them, epoxy resin having excellent heat resistance, moisture resistance, adhesion and the like is one of the most suitable resins.
The resin contained in the conductive resin layer is preferably contained in an amount of 25 vol% or more and 65 vol% or less with respect to the total volume of the conductive resin.
Further, the conductive resin layer preferably contains a curing agent together with the thermosetting resin. When an epoxy resin is used as the base resin, various known compounds such as a phenol resin, an amine-based compound, an acid anhydride-based compound, and an imidazole-based compound can be used as the curing agent for the epoxy resin.

The thickness of each conductive resin layer in the central portion in the height direction of the first base electrode layer 26a located on the first end surface 12e and the second base electrode layer 26b located on the second end face 12f is, for example, It is preferably about 10 μm or more and 200 μm or less.
Further, when the base electrode layer is provided on the surfaces of the first main surface 12a and the second main surface 12b, and the first side surface 12c and the second side surface 12d, the first main surface 12a and the second side surface 12a and the second side surface 12d. The conductive resins in the central portion in the length direction of the first base electrode layer 26a and the second base electrode layer 26b located on the surfaces of the main surface 12b and the first side surface 12c and the second side surface 12d, respectively. The thickness of the layer is preferably about 5 μm or more and 50 μm or less.

When the base electrode layer is a thin film layer, the thin film layer is a layer of 1 μm or less formed by a thin film forming method such as a sputtering method or a thin film deposition method and on which metal particles are deposited.

The first plating layer 28a is arranged so as to cover the first base electrode layer 26a. Specifically, the first plating layer 28a is arranged on the first end surface 12e of the surface of the first base electrode layer 26a, and the first main surface 12a and the first surface of the surface of the first base electrode layer 26a are the first. It is preferable that the main surface 12b, the first side surface 12c, and the second side surface 12d of 2 are also provided. The first plating layer 28a may be arranged only on the surface of the first base electrode layer 26a arranged on the first end surface 12e.

The second plating layer 28b is arranged so as to cover the second base electrode layer 26b. Specifically, the second plating layer 28b is arranged on the second end surface 12f of the surface of the second base electrode layer 26b, and the first main surface 12a and the first surface of the surface of the second base electrode layer 24b are the first. It is preferable that the main surface 12b, the first side surface 12c, and the second side surface 12d of 2 are also provided. The second plating layer 28b may be arranged only on the surface of the second base electrode layer 26b arranged on the second end surface 12f.

Further, as the first plating layer 28a and the second plating layer 28b (hereinafter, also simply referred to as a plating layer), at least selected from, for example, Cu, Ni, Sn, Ag, Pd, Ag—Pd alloy, Au and the like. Includes one.
The plating layer may be formed by a plurality of layers. In this case, the plating layer preferably has a two-layer structure of a Ni plating layer and a Sn plating layer. By providing the Ni plating layer so as to cover the surface of the base electrode layer 24, it is possible to prevent the base electrode layer from being eroded by the solder used for mounting when the multilayer ceramic capacitor 10 is mounted. .. Further, by providing the Sn plating layer on the surface of the Ni plating layer, when mounting the multilayer ceramic capacitor 10, the wettability of the solder used for mounting is improved, and the mounting can be easily performed.

The thickness of one layer of the plating layer is preferably 2 μm or more and 15 μm or less.

The external electrode 24 may be formed only by the plating layer without providing the base electrode layer. Hereinafter, a structure in which the plating layer is provided without providing the base electrode layer will be described.
Each of the first external electrode 24a and the second external electrode 24b may not be provided with a base electrode layer, and a plating layer may be formed directly on the surface of the laminate 12. That is, the multilayer ceramic capacitor 10 may have a structure including a plating layer electrically connected to the first internal electrode layer 16a or the second internal electrode layer 16b. In such a case, the plating layer may be formed after the catalyst is arranged on the surface of the laminated body 12 as a pretreatment.
The plating layer preferably includes a lower layer plating electrode formed on the surface of the laminated body 12 and an upper layer plating electrode formed on the surface of the lower layer plating electrode.
The lower-layer plating electrode and the upper-layer plating electrode preferably contain, for example, at least one metal selected from Cu, Ni, Sn, Pb, Au, Ag, Pd, Bi, Zn, and the like, or an alloy containing the metal.
The lower layer plating electrode is preferably formed using Ni having solder barrier performance, and the upper layer plating electrode is preferably formed using Sn or Au having good solder wettability. Further, for example, when the first internal electrode layer 16a and the second internal electrode layer 16b are formed using Ni, the lower layer plating electrode is preferably formed using Cu having good bondability with Ni. .. The upper layer plating electrode may be formed as needed, and the first external electrode 24a and the second external electrode 24b may each be composed of only the lower layer plating electrode.
As the plating layer, the upper layer plating electrode may be the outermost layer, or another plating electrode may be formed on the surface of the upper layer plating electrode.
The thickness per layer of the plating layer arranged without providing the base electrode layer is preferably 1 μm or more and 15 μm or less. The plating layer preferably does not contain glass. The metal ratio per unit volume of the plating layer is preferably 99 vol% or more.

Further, a metal layer 30 is arranged on the first main surface 12a and the second main surface 12b of the laminated body 12, and on the first side surface 12c and the second side surface 12d so as to orbit the laminated body 12. There is. The thickness of the metal layer 30 is preferably formed to be smaller than the thickness of the first external electrode 24a and the second external electrode 24b. The metal layer 30 includes, for example, at least one selected from Cu, Ni, Ag, Pd, Ag—Pd alloy, Au and the like. The metal layer 30 may include glass. The glass contains at least one selected from B, Si, Ba, Mg, Al, Li and the like. Further, instead of glass, a ceramic material of the same type as the ceramic layer 14 may be used.
The metal layer 30 may be formed of a single layer or may be formed of a plurality of layers.
The thickness (thickest portion) of the metal layer 30 is preferably 10 μm or more and 500 μm or less.
A plating layer is not formed on the surface of the metal layer 30.
Further, the length in the length direction z connecting the first end face 12e and the second end face 12f of the metal layer 30 is the length direction z connecting the first end face 12e and the second end face 12f of the laminated body 12. The length is preferably 1/2 or less of the length.

Further, on the first main surface 12a, on the second main surface 12b, on the first side surface 12c, and on the first side surface 12c of the laminate 12 located between the first external electrode 24a and the second external electrode 24b. It has a protective layer 32 arranged on the side surface 12d of 2 and so as to cover the metal layer 30. The protective layer 32 completely covers the metal layer 30, and is a surface on which the first external electrode 24a and the second external electrode 24b face each other on the first main surface 12a and the second main surface of the laminate 12. It is provided on 12b, on the first side surface 12c, and on the second side surface 12d.

The material of the protective layer 32, if the capacitor can be used, for example, a dielectric ceramic containing a component such as BaTiO _3, CaTiO _3, SrTiO ₃ or CaZrO _3,. When the above-mentioned dielectric material is contained as a main component, the sub-content is smaller than that of the main components such as Mn compound, Fe compound, Cr compound, Co compound and Ni compound, depending on the desired characteristics of the laminate 12. Those to which the component is added may be used.

Further, as the material of the protective layer 32, when a piezoelectric ceramic is used for the laminated body 12, for example, a PZT (lead zirconate titanate) ceramic material or the like can be mentioned.
When a semiconductor ceramic is used as the material of the protective layer 32, for example, a spinel-based ceramic material or the like can be mentioned.
Further, as the material of the protective layer 32, when a magnetic ceramic material is used for the laminated body 12, for example, a ferrite ceramic material or the like can be mentioned.

The ceramic material used for the protective layer 32 may be different from the ceramic material used for the laminate 12, but it is preferable to use the same material. By using the same material, the adhesion between the protective layer 32 and the laminated body 12 can be improved.

The protective layer 32 may be formed of a single layer or a plurality of layers. The thickness of the protective layer 32 may be larger than the thickness of the metal layer 30 and equal to or smaller than the thickness of the thickest portion of the first external electrode 24a and the second external electrode 24b. preferable. At this time, the surface and the laminated body of the first external electrode 24a provided on the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d of the laminated body 12. The surfaces of the second external electrodes 24b provided on the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d of the twelve are substantially parallel to the mounting surface. It is preferable that it is provided so as to be.

The dimension of the laminated ceramic capacitor 10 including the laminated body 12, the first external electrode 24a and the second external electrode 24b in the length direction z is defined as the L dimension, and the laminated body 12, the first external electrode 24a and the second external electrode are set to L dimension. The height x dimension of the multilayer ceramic capacitor 10 including the electrode 24b is defined as the T dimension, and the width direction y of the multilayer ceramic capacitor 10 including the laminate 12, the first external electrode 24a and the second external electrode 24b is defined as the T dimension. W dimension.
The dimensions of the multilayer ceramic capacitor 10 are such that the L dimension in the length direction z is 1.0 mm or more and 7.0 mm or less, the W dimension in the width direction y is 0.5 mm or more and 6.0 mm or less, and the T dimension in the height direction x is 0. It is preferably 5.5 mm or more and 6.0 mm or less.

According to the multilayer ceramic capacitor 10 shown in FIG. 1, the metal layer 30 is placed on the first main surface 12a and the second main surface 12b of the laminated body 12, and on the first side surface 12c and the second side surface 12d. By arranging so as to orbit the laminated body 12, it is possible to cover the periphery of the laminated body 12 at the central portion of the laminated body 12. This makes it possible to tighten the laminate 12 by heat shrinkage of the metal layer paste when forming the metal layer 30 at the central portion of the laminate 12 where tightening does not work with the conventional multilayer ceramic capacitor. As a result, it is possible to exert the effect of reducing the residual stress and suppress layer peeling.

Further, according to the multilayer ceramic capacitor 10 shown in FIG. 1, on the first main surface 12a and the second main surface of the laminated body 12 located between the first external electrode 24a and the second external electrode 24b. Since the protective layer 32 is arranged on the 12b, on the first side surface 12c, on the second side surface 12d, and so as to cover the metal layer 30, the external electrode 24 and the metal formed on the laminate 12 are formed. The layer 30 can be covered with a non-conductive protective layer 32. Therefore, it is possible to prevent short-circuit defects and migration between the first external electrode 24a and the second external electrode 24b.

Further, according to the multilayer ceramic capacitor 10 shown in FIG. 1, since the protective layer 32 and the metal layer 30 are in direct contact with each other by not forming the plating layer on the surface of the metal layer 30, the minute amount on the metal layer 30 is reached. The protective layer 32 penetrates into the uneven surface, and the adhesion between the metal layer 30 and the dielectric protective layer 32 is improved by the anchor effect. Further, by not forming the plating layer on the surface of the metal layer 30, the thickness of the metal layer 30 can be increased by the thickness of the plating layer, the tightening of the metal layer 30 to the laminate 12 becomes large, and layer peeling occurs. The effect of suppressing is improved.

Next, a modification of the multilayer ceramic capacitor according to the embodiment of the present invention will be described. FIG. 7 is an external perspective view showing an example of a modification of the multilayer ceramic capacitor according to the embodiment of the present invention. FIG. 8 is a side view of FIG. 7 showing a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 9 is a cross-sectional view taken along the line IX-IX of FIG. 7 showing a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 10 is a cross-sectional view taken along the line XX of FIG. 9 showing a multilayer ceramic capacitor according to an embodiment of the present invention. FIG. 11 is a cross-sectional view taken along the line XI-XI of FIG. 9 showing a multilayer ceramic capacitor according to an embodiment of the present invention.
In the multilayer ceramic capacitor 110 shown in FIGS. 7 to 11, the same parts as those of the multilayer ceramic capacitor 10 shown in FIGS. 1 to 5 are designated by the same reference numerals, and the description thereof will be omitted.

The configuration of the multilayer ceramic capacitor 110 shown in FIGS. 7 to 11 differs from the configuration of the multilayer ceramic capacitor 10 shown in FIGS. 1 to 3, in that the protective layer 132 is the tip of the first external electrode 24a and the second outside. It is a point provided so as to enter the lower part of the tip of the electrode 24b.

The protective layer 132 is on the first main surface 12a, the second main surface 12b, and the first side surface 12c of the laminated body 12 located between the first external electrode 24a and the second external electrode 24b. , And are arranged so as to cover the metal layer 30 on the second side surface 12d, but are further provided so as to enter below the tip of the first external electrode 24a and the tip of the second external electrode 24b. Be done. In other words, a part of the protective layer 132 is provided so as to be located between the first external electrode 24a and the laminated body 12, and between the second external electrode 24b and the laminated body 12.

The protective layer 132 may be provided so that there is a gap between the tip of the first external electrode 24a and the protective layer 132, and between the tip of the second external electrode 24b and the protective layer 132.

The thickness of the protective layer 132 may be larger than the thickness of the metal layer 30 and equal to or smaller than the thickness of the thickest portion of the first external electrode 24a and the second external electrode 24b. preferable. At this time, the surface and the laminated body of the first external electrode 24a provided on the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d of the laminated body 12. The surfaces of the second external electrodes 24b provided on the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d of the twelve are substantially parallel to the mounting surface. It is preferable that it is provided so as to be. Therefore, the thickness of the protective layer 132 provided so as to enter the lower portion of the tip of the first external electrode 24a and the tip of the second external electrode 24b is such that the thickness of the protective layer 132 is on the first main surface 12a of the laminated body 12 and the second main. On the surface 12b, on the first side surface 12c, on the surface of the first external electrode 24a provided on the second side surface 12d, on the first main surface 12a of the laminated body 12, on the second main surface 12b, first The surface of the second external electrode 24b provided on the side surface 12c of 1 and the surface of the second side surface 12d is adjusted so as to be substantially parallel to the mounting surface.

The multilayer ceramic capacitor 110 shown in FIG. 7 has the same effect as that of the multilayer ceramic capacitor 10 shown in FIG. 1, and also has the following effects.
That is, the protective layer 132 is on the first main surface 12a, the second main surface 12b, and the first side surface of the laminated body 12 located between the first external electrode 24a and the second external electrode 24b. It is arranged on 12c and on the second side surface 12d so as to cover the metal layer 30, and further enters the lower portion of the tip of the first external electrode 24a and the tip of the second external electrode 24b. Since the protective layer 132 is provided, the protective layer 132 is covered with the laminated body 12, the first external electrodes 24a and the second by covering the boundary portion between the protective layer 132 and the laminated body 12 with the first external electrode 24a and the second external electrode 24b. It is possible to fix the external electrode 24b from three directions, and the mechanical strength of the protective layer 132 can be improved. Further, on the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d of the laminated body 12 of the first external electrode 24a and the second external electrode 24b. The length in the length direction z connecting the first end surface 12e and the second end surface 12f provided can be increased, and the intrusion of moisture into the laminated body 12 can be reduced. As a result, the monolithic ceramic capacitor 110 can improve the moisture resistance and suppress structural defects due to the intrusion of moisture.

2. 2. Method for Manufacturing Laminated Ceramic Electronic Components Next, a method for manufacturing laminated ceramic electronic components according to the present invention will be described. Here, a method for manufacturing the above-mentioned multilayer ceramic capacitor 10 as a multilayer ceramic electronic component will be described.

First, a dielectric sheet and a conductive paste for internal electrodes are prepared. The conductive paste for the dielectric sheet and the internal electrode contains a binder and a solvent, and known organic binders and organic solvents can be used.

Next, the conductive paste for the internal electrode is printed on the dielectric sheet in a predetermined pattern by, for example, screen printing or gravure printing, to form the internal electrode pattern.

Subsequently, a predetermined number of dielectric sheets for the outer layer on which the internal electrode pattern is not printed are laminated, and then the dielectric sheets on which the internal electrode pattern is printed are sequentially laminated, and further, the internal electrode pattern is printed. A predetermined number of dielectric sheets for the outer layer that have not been printed are laminated to produce a laminated sheet.

Then, the laminated sheet is pressure-bonded in the laminated direction by means such as a hydrostatic press to produce a laminated block.

After that, the laminated block is cut into a predetermined shape and size, and raw laminated chips are cut out. At this time, the raw laminate chips may be subjected to barrel polishing or the like to round the corners and ridges of the laminate.

Subsequently, the metal layer 30 and the protective layer 32 are formed. The metal layer 30 and the protective layer 32 can be formed on the laminated body 12 after firing or on the raw laminated body before firing.

First, a method of forming the metal layer 30 and the protective layer 32 on the laminated body 12 after firing will be described.
The cut out raw laminate chips are fired, the first internal electrode layer is pulled out to the first end face, and the laminate 12 in which the second internal electrode layer is pulled out to the second end face is produced. The firing temperature of the raw laminate chips depends on the ceramic material and the material of the conductive paste for the internal electrodes, but is preferably 900 ° C. or higher and 1400 ° C. or lower. Further, at this time, with respect to the laminated body 12, the corners and ridges of the laminated body 12 may be rounded by barrel polishing or the like.

Then, a metal layer paste is applied on the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d of the laminated body 12 so as to orbit the laminated body 12, and dried. To process. As a method of applying the metal layer paste, the metal layer paste is applied to a predetermined place using a roller, or the metal layer paste is applied by an inkjet method.

Subsequently, the laminated body 12 obtained by drying the metal layer paste is placed on the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d of the laminated body 12. A paste serving as a protective layer (protective layer paste) is applied and dried so as to go around 12 and further cover the dried portion of the metal layer paste. As a method of applying the protective layer paste, the protective layer paste is applied to a predetermined place using a roller, or the protective layer paste is applied by an inkjet method.

After that, the metal layer paste and the protective layer paste are applied, the dried laminate 12 is fired, the dried metal layer paste and the protective layer paste are sintered, and the metal layer 30 and the protective layer 32 are formed on the laminate 12. .. The firing temperature depends on the material of the protective layer 32 and the material of the conductive paste for the internal electrode, but is preferably 900 ° C. or higher and 1400 ° C. or lower.

Subsequently, the external electrodes 24 are formed on both end faces of the laminated body 12 on which the metal layer 30 and the protective layer 32 are formed.

A method of forming the base electrode layer when the base electrode layer of the external electrode 24 is a baking layer will be described.
In order to form the baking layer of the external electrode 24, for example, a glass component is formed on the exposed portion of the first extraction portion 20a of the first internal electrode layer 16a exposed from the first end surface 12e on the surface of the laminate 12. A conductive paste for an external electrode containing metal and metal is applied and baked by a method such as dipping to form a first base electrode layer. Similarly, in order to form the baking layer of the outer electrode 24, for example, the exposed portion of the second drawer portion 20b of the second inner electrode layer 16b exposed from the second end surface 12f of the laminated body 12. The conductive paste for an external electrode containing a glass component and a metal is coated and baked with the conductive paste for an external electrode by a method such as dipping to form a second base electrode layer. At this time, the temperature of the baking process is preferably 700 ° C. or higher and 900 ° C. or lower.

Next, a method of forming the base electrode layer when the base electrode layer is formed of the conductive resin layer will be described.
The conductive resin layer may be formed on the surface of the baking layer, or the conductive resin layer may be formed alone on the surface of the laminate 12 without forming the baking layer.
As a method for forming the conductive resin layer, a conductive resin paste containing a thermosetting resin and a metal component is applied to the surface of the baking layer or the laminate 12, and heat treatment is performed at a temperature of 250 ° C. or higher and 550 ° C. or lower to carry out the resin. Is thermoset to form a conductive resin layer. The atmosphere during the heat treatment at this time is preferably an N ₂ atmosphere. Further, in order to prevent the resin from scattering and to prevent the oxidation of various metal components, the oxygen concentration is preferably suppressed to 100 ppm or less.

In addition, a method of forming the base electrode layer when the base electrode layer is formed of a thin film layer will be described.
When the base electrode layer is formed of a thin film layer, the base electrode layer can be formed by a thin film forming method such as a sputtering method or a thin film deposition method. The base electrode layer formed of the thin film layer is a layer of 1 μm or less in which metal particles are deposited.

Further, a plating layer may be provided on the exposed portion of the internal electrode layer 16 of the laminated body 12 without providing the base electrode layer.
The first end face 12e and the second end face 12f of the laminate 12 are plated to form a base plating electrode on the exposed portion of the internal electrode layer 16. Either electrolytic plating or electroless plating may be used for the plating treatment, but electroless plating requires pretreatment with a catalyst or the like in order to improve the plating precipitation rate, which complicates the process. There are disadvantages. Therefore, it is usually preferable to use electrolytic plating. As the plating method, it is preferable to use barrel plating. Further, if necessary, the upper layer plating electrode may be similarly formed on the surface of the lower layer plating electrode.

After that, a plating layer is formed on the surface of the base electrode layer, the surface of the conductive resin layer, the surface of the base plating layer, and the surface of the upper plating layer, and the external electrode 24 is formed.
In the multilayer ceramic capacitor 10 shown in FIG. 1, a Ni plating layer and a Sn plating layer are formed as plating layers on the surface of the baking layer. The Ni plating layer and the Sn plating layer are sequentially formed by, for example, a barrel plating method.

Next, a method of forming the metal layer 30 and the protective layer 32 on the laminated body 12 before firing will be described.
A metal layer paste is applied on the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d of the laminate 12 so as to orbit the laminate 12, and the laminate is dried. .. As a method of applying the metal layer paste, the metal layer paste is applied to a predetermined place using a roller, or the metal layer paste is applied by an inkjet method.

Subsequently, the laminated body 12 obtained by drying the metal layer paste is placed on the first main surface 12a, the second main surface 12b, the first side surface 12c, and the second side surface 12d of the laminated body 12. A paste serving as a protective layer (protective layer paste) is applied and dried so as to go around 12 and further cover the dried portion of the metal layer paste. As a method of applying the protective layer paste, the protective layer paste is applied to a predetermined place using a roller, or the protective layer paste is applied by an inkjet method.

After that, the metal layer paste and the protective layer paste are applied, the dried laminate 12 is fired, the dried metal layer paste and the protective layer paste are sintered, and the metal layer 30 and the protective layer 32 are formed on the laminate 12. .. The firing temperature depends on the material of the protective layer 32 and the material of the conductive paste for the internal electrode, but is preferably 900 ° C. or higher and 1400 ° C. or lower. Further, at this time, with respect to the laminated body 12, the corners and ridges of the laminated body 12 may be rounded by barrel polishing or the like.

Subsequently, the external electrodes 24 are formed on both end faces of the laminated body 12 on which the metal layer 30 and the protective layer 32 are formed. The method of forming the external electrode 24 is the same as the method of forming the external electrode 24 described in the method of forming the metal layer 30 and the protective layer 32 on the laminated body 12 after firing, and thus the description thereof will be omitted. To do.

In this way, the monolithic ceramic capacitor 10 shown in FIG. 1 is manufactured.

As described above, the embodiments of the present invention are disclosed in the above description, but the present invention is not limited thereto.
That is, various changes can be made to the above-described embodiments with respect to the mechanism, shape, material, quantity, position, arrangement, etc., without departing from the scope of the technical idea and purpose of the present invention. They are, and they are included in the present invention.

10, 110 Multilayer Ceramic Capacitor 12 Laminated body 12a First main surface 12b Second main surface 12c First side surface 12d Second side surface 12e First end surface 12f Second end surface 14 Ceramic layer 15a Outer layer part 15b Inner layer part 16 Internal electrode layer 16a First internal electrode layer 16b Second internal electrode layer 18a First counter electrode part 18b Second counter electrode part 20a First lead electrode part 20b Second lead electrode part 22a Side part ( W gap)
22b side (L gap)
24 External electrode 24a First external electrode 24b Second external electrode 26 Base electrode layer 26a First base electrode layer 26b Second base electrode layer 28 Plating layer 28a First plating layer 28b Second plating layer 30 Metal Layers 32, 132 Protective layer x Height direction y Width direction z Length direction

Claims (3)

A plurality of laminated ceramic layers and a plurality of internal electrode layers laminated on the ceramic layer are included, and the first main surface and the second main surface facing each other in the height direction are orthogonal to the height direction. A laminate including a first side surface and a second side surface facing each other in the width direction, and a first end face and a second end face facing each other in the length direction orthogonal to the height direction and the width direction.
It is arranged on the first end face and on a part of the first main surface, a part of the second main surface, a part of the first side surface, and a part of the second side surface. With the first external electrode,
It is arranged on the second end surface and on a part of the first main surface, a part of the second main surface, a part of the first side surface, and a part of the second side surface. With the second external electrode,
With
On the first main surface, the second main surface, the first side surface, and the second side surface of the laminate, metal layers arranged so as to orbit the laminate are provided.
On the first main surface, on the second main surface, on the first side surface, and on the second surface of the laminate located between the first external electrode and the second external electrode. A laminated ceramic electronic component having a protective layer arranged on the side surface and arranged so as to cover the metal layer. A part of the protective layer is provided so as to be located between the first external electrode and the laminated body, and between the second external electrode and the laminated body, claim 1. Multilayer ceramic electronic components described in. The laminated ceramic electronic component according to claim 1 or 2, wherein a plating layer is not formed on the metal layer.