121, and the second electrode layer 132 may be disposed on the fourth surface 4 of the body and connected to the second internal electrode 122.

That is, the first internal electrode 121 may not be connected to the second electrode layer 132 but be connected to the first electrode layer 131, and the second internal electrode 122 may not be connected to the first electrode layer 131 but be connected to the second electrode layer 132. Accordingly, the first internal electrode 121 may be formed to be spaced apart from the fourth surface 4 by a predetermined distance, and the second internal electrode 122 may be formed to be spaced apart from the third surface 3 by a predetermined distance.

In this case, the first and second internal electrodes 121 and 122 may be electrically separated from each other by the dielectric layer 111 disposed therebetween.

The body 110 may be formed by alternately stacking ceramic green sheets on which the first internal electrodes 121 are printed and ceramic green sheets on which the second internal electrodes 122 are printed, and then firing the ceramic green sheets.

Materials forming the internal electrodes 121 and 122 are not particularly limited, and materials having excellent electrical conductivity may be used. For example, the internal electrodes 121 and 122 may include one or more of nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof.

In addition, the internal electrodes 121 and 122 may be formed by printing a conductive paste for internal electrodes including one or more of nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof on a ceramic green sheet. A screen printing method or a gravure printing method may be used as a method of printing the conductive paste for internal electrodes, but the present disclosure is not limited thereto.

Also, the average thickness te of the internal electrodes 121 and 122 may not be particularly limited. For example, the average thickness te of the internal electrodes 121 and 122 may be 0.2 μm or greater and 2 μm or less.

However, in general, when the internal electrode is formed to be as thin to be less than 0.6 μm, in particularly, when the thickness of the internal electrode is less than 0.35 μm, the reliability of the multilayer electronic component 100 may be more problematic.

According to an exemplary embodiment in the present disclosure, by controlling the grains of the extensions 131b2 and 132b2 of the plating layers, the reliability may be improved even when the average thickness te of the internal electrodes 121 and 122 is 0.35 μm or less.

Therefore, when the thickness of the internal electrodes 121 and 122 is 0.35 μm or less, the effect according to the present disclosure may be more remarkable, and miniaturization and high capacitance of the multilayer electronic component may be more easily achieved.

Here, the average thickness te of the internal electrodes 121 and 122 may refer to an average thickness te of one internal electrode.

The average thickness te of the internal electrodes 121 and 122 may be measured by scanning an image of a cross-section body 110 in the length and thickness directions (L-T) with a scanning electron microscope (SEM) with magnification of 10,000. More specifically, an average value may be measured by measuring the thicknesses of one internal electrode at 30 equally spaced points in the length direction in the scanned image. The 30 equally spaced points may be designated in the capacitance forming portion Ac. In addition, when the average value is measured by extending the average value measurement to ten internal electrodes, the average thickness of the internal electrodes may be further generalized. Other methods and/or tools appreciated by one of ordinary skill in the art, even if not described in the present disclosure, may also be used.

The external electrodes 131 and 132 may be disposed on the third and fourth surfaces 3 and 4 of the body 110. The external electrodes 131 and 132 may include the first and second external electrodes 131 and 132 disposed on the third and fourth surfaces 3 and 4 of the body 110 and connected to the first and second internal electrodes 121 and 122, respectively. At this time, a region of the external electrode 131 and 132 disposed at the corner of the body 110 may be referred to as a corner portion, a region of the external electrode 131 and 132 disposed on the third and fourth surfaces of the body 110 may be referred to as a connection portion, and a region of the external electrode 131 and 132 disposed on the first and second surfaces of the body may be referred to as a band portion.

In the present exemplary embodiment, although the structure in which the multilayer electronic component 100 has two external electrodes 131 and 132 is described, the number and shape of the external electrodes 131 and 132 may be changed according to the shape of the internal electrodes 121 and 122 or other purposes.

The external electrodes 131 and 132 may include the plating layers 131a and 132a and the plating layers 131b and 132b disposed on the electrode layer.

The electrode layers 131a and 132a may be formed using any material as long as the material has electrical conductivity, such as metal, and a specific material may be determined in consideration of electrical properties and structural stability.

In an exemplary embodiment, the electrode layers 131a and 132a may be fired electrodes including conductive metal and glass.

In an exemplary embodiment, the electrode layers 131a and 132a may be a resin electrode including conductive metal and a resin.

In an exemplary embodiment, the electrode layers 131a and 132a may include more than 95 at % of metal elements. That is, the electrode layers 131a and 132a may be substantially formed of metal.

In addition, the electrode layers 131a and 132a may have a form in which a fired electrode and a resin electrode are sequentially formed on the body. In addition, the electrode layers 131a and 132a may be formed by transferring a sheet including conductive metal on the body or by transferring a sheet including conductive metal on the fired electrode.

A material of the conductive metal used in the electrode layers 131a and 132a is not particularly limited as long as the material may be electrically connected to the internal electrode for the formation of capacitance, and may include, for example, one or more selected from the group consisting of nickel (Ni), copper (Cu), palladium (Pd), silver (Ag), gold (Au), platinum (Pt), tin (Sn), tungsten (W), titanium (Ti), and alloys thereof.

The plating layers 131b and 132b may include the extensions 131b2 and 132b2 extending onto the body 110 and contacting the body, and the extensions 131b2 and 132b2 may include one or more grains in which an angle between the surface BS of the body in contact with the extension and a major axis Lx of the grain is 70 degrees or greater and 110 degrees or less.

The plating layers 131b and 132b may basically serve to protect the electrode layers 131a and 132a and/or improve mounting characteristics.

Referring to FIGS. 7 and 8 for Comparative Example which is a plating layer structure of the related art, unlike the interface of the electrode layer 32a and the plating layer 32b, the interface between the body 110 and the plating layer 32b has a low bonding force, and thus, the interface between the body 110 and the plating layer 32b may be open by stress that occurs during plating or external force after plating. In addition, the open interface may become a path of moisture penetration to cause deterioration of moisture resistance reliability. Meanwhile, an additional plating layer 32c may be disposed on the plating layer 32b of the related art.

As a result of research conducted by the present inventors, it was found that the general plating layer 32b of the related art includes grains grown upon receiving charges from an electrode layer, so that a growth direction of grains of the plating layer at the end of the band portion was a horizontal direction, and thus, a bonding force with the body was low.

Referring to a microstructure of the plating layer 32b, fine grains G1′ are formed in a first region Z1′ adjacent to the electrode layer 32a, and grains G2′ are grown to be large in the second region Z2′ on the first region Z1′. At this time, a direction of the major axis Lx of the grain G2′ may be considered as a growth direction of the grains. As can be seen from the growth direction of the grains, a plating tissue has a shape grown from the electrode layer 32a, and the grain of a portion in contact with the body 110 has a growth direction parallel to the surface of the body, so that, although the plating layer 32b is bonded to the body 110, it may be difficult for the plating layer 32b and the body 110 to have a strong bonding force therebetween.

Meanwhile, according to an exemplary embodiment in the present disclosure, when a grain in which an angle between the surface BS of the body in contact with the extension and the major axis Lx of the grain is 70 degrees or greater and 110 degrees or less is included in the extensions 131b2 and 132b2 of the plating layer, a bonding force between the body 110 and the plating layers 131b and 132b may be improved, and accordingly, the moisture resistance reliability of the multilayer electronic component may be improved.

In an exemplary embodiment, referring to FIGS. 5 and 6, the extensions 131b2 and 132b2 include a first region Z1 adjacent to the body and a second region Z2 disposed on the first region, and when a grain included in the first region is a first grain G1, a grain included in the second region is a second grain G2, and an angle between a major axis of the second grain and the surface of the body in contact with the extension is θ2, at least one of the second grains may satisfy that θ2 is 70 degrees or greater and 110 degrees or less.

When θ2 is 70 degrees or greater 110 degrees or less, the grain may be considered as a grain that has grown in a longitudinal direction, and when the extensions 131b2 and 132b2 do not include grains grown in the longitudinal direction, a bonding force between the extensions 131b2 and 132b2 and the body may be lowered and the extension may fall from the body interface.

More preferably, at least one of the second grains G2 may satisfy that θ2 is 80 degrees or more and 100 degrees or less. More preferably, an θ2 average value of the second grains may be 70 degrees or greater and 110 degrees or less.

Meanwhile, FIGS. 1 through 6 illustrate a structure in which the extensions 131b2 and 132b2 are disposed in the band portion of the external electrode, but the present disclosure is not limited thereto, and when the external electrode does not have a band portion, a portion in which the plating layer is in contact with the body may be considered as an extension.

Table 1 below is a result of measuring and evaluating moisture resistance reliability of Comparative Example having the plating layer structure of FIGS. 7 and 8 and Example having the plating layer structure of FIGS. 5 and 6.

Referring to FIGS. 7 and 8, In Comparative Example, it can be seen that the grains are grown in a transverse direction at an angle less than 70 degrees with respect to the surface of the body in contact with the extension, at the extension, which is a portion in which the plating layer is in contact with the body.

Meanwhile, referring to FIGS. 5 and 6, in Example, the extensions 131b2 and 132b2 of the plating layers include grains in which an angle between the surface BS of the body in contact with the extension and the major axis Lx of the grain is 70 degrees or greater and 110 degrees or less, confirming that the grains are grown in a longitudinal direction.

For the evaluation of moisture resistance reliability, 400 samples of each of Comparative Example and Examples were prepared, and after applying 1 VR (=rated voltage) of the evaluation model for 3 hours under the condition of 85° C. and humidity of 85%, a case in which insulation resistance was dropped to 10⁷Ω or lower was determined as a defect and the number samples, which were defective, was described.

TABLE 1

Evaluation of moisture
Defect rate of moisture

Classification
resistance reliability
resistance reliability

Comparative
8/400
2%

Example

Example
1/400
0.25%