JP2013165181A - Multi-layered electronic member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-layered electronic member capable of suppressing structural defects and reducing occurrence of cracks.SOLUTION: A multi-layered electronic member 1 comprises an element pack 2 and external electrodes 3, 4. Each of the external electrodes 3, 4 includes a first member 10 positioned on main surfaces 2c, 2d, and a second member 12 continuous with the first member 10 and positioned on side surfaces 2e, 2f. An inner edge 10a of the first member 10 is arc-shaped in a direction in which a pair of end surfaces 2a, 2b are opposed, when viewed from a direction in which a pair of main surfaces 2c, 2d are opposed. An inner edge 12a of the second member 12 is arc-shaped in the direction in which the pair of end surfaces 2a, 2b are opposed, when viewed from a direction in which a pair of side surfaces 2e, 2f are opposed. A radius of curvature R1 of the edge 10a of the first member 10, a radius of curvature R2 of the edge 12a of the second member 12, a height dimension T, and a width dimension W satisfy the relationships of W>R1, T>R2, W/R1<T/R2.

Description

  The present invention relates to a multilayer electronic component such as a multilayer capacitor.

  As a conventional multilayer electronic component, for example, one described in Patent Document 1 is known. For example, the capacitor described in Patent Document 1 includes a stacked body in which a plurality of internal electrodes are stacked with a dielectric layer interposed therebetween, and external electrodes disposed on both end surfaces of the stacked body. In this multilayer electronic component, external electrodes are formed across four side surfaces that connect the end surfaces and end surfaces of the multilayer body.

Japanese Patent Laid-Open No. 2002-298643

  By the way, in recent years, multilayer electronic components have been miniaturized, and as a result, it has become difficult to ensure the strength of the multilayer electronic components, resulting in structural defects such as cracks and chips during handling and mounting of the multilayer electronic components. There was a drowning to do. In addition, the multilayer electronic component has a problem that, for example, cracking occurs in the element body when bending stress is applied.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a laminated electronic component that can suppress structural defects and reduce the occurrence of cracks.

In order to solve the above-described problems, a multilayer electronic component according to the present invention includes a pair of end surfaces facing each other, a pair of main surfaces extending so as to connect the pair of end surfaces and facing each other, and a pair of main surfaces. And a plurality of dielectric layers and a plurality of internal electrodes stacked in the opposing direction of the pair of main surfaces, and each end face side of the element body. And a pair of external electrodes connected to the corresponding internal electrodes, each external electrode being located on each main surface, continuous to the first portion and located on each side surface A second portion and a third portion that is continuous with the first and second portions and is located on each end surface; and the first portion is a facing direction of the pair of end surfaces when viewed from a facing direction of the pair of main surfaces. The inner edge of the second portion has an arc shape, and the second portion is viewed from the opposing direction of the pair of side surfaces. The inner edges of the pair of end faces in the opposing direction have an arc shape, the radius of curvature R1 of the edge of the first portion, the radius of curvature R2 of the edge of the second portion, and the dimension T between the outer surfaces of the first portion. , And the dimension W between the outer surfaces of the second part is
W> R1
T> R2
W / R1 <T / R2
It is characterized by satisfying the relationship.

  In this multilayer electronic component, the radius of curvature R1 of the edge of the first part, the radius of curvature R2 of the edge of the second part, the dimension T between the outer surfaces of the first part, and the dimension W between the outer surfaces of the second part. However, the relations W> R1, T> R2, and W / R1 <T / R2 are satisfied. As described above, since the radius of curvature R1 of the edge of the first portion is set to be small, the stress can be dispersed in the first portion. Thereby, the stress applied to the element body can be dispersed in the first portion, and the occurrence of cracks in the element body can be suppressed. Moreover, since the difference of the curvature radius R1 with respect to the width dimension W is small, the area of the 1st part arrange | positioned at each main surface can be ensured, and the 1st part covers each main surface widely. Thereby, structural defects, such as a crack and a chip, can be suppressed.

  The curvature radius R1 of the edge of the first portion is preferably 0.20 mm to 0.45 mm. Thus, by setting the edge curvature radius R1 to 0.20 mm or more, the area of the first portion can be ensured well, and structural defects such as cracks and chips can be suppressed. Further, by setting the edge radius of curvature R1 to 0.45 mm or less, the edge has an arc shape with a large curvature, so that the stress can be more effectively dispersed and the occurrence of cracks can be further reduced.

  The radius of curvature R1 of the edge of the first part is preferably larger than the dimension T between the outer surfaces of the first part. According to such a configuration, since the area where the first portion covers each main surface can be secured satisfactorily, structural defects such as cracks and chips can be further suppressed.

  The dimension T between the outer surfaces of the first part is preferably smaller than the dimension W between the outer surfaces of the second part and the dimension between the outer surfaces of the third part. As described above, the above configuration is particularly effective for a structure in which the height dimension is smaller than the width dimension and the length dimension, that is, a low-profile structure with low strength, and a structural defect is caused in a low-profile multilayer electronic component. Can be suppressed.

  The dimension T between the outer surfaces of the first part is preferably less than 3/4 of the dimension W between the outer surfaces of the second part. As described above, the above configuration is particularly effective for a structure having a height dimension smaller than a width dimension, that is, a low-profile structure with low strength, and structural defects can be suppressed in a low-profile multilayer electronic component.

The radius of curvature R1 of the edge of the first part is
1 / 2W <R1 <W
And the radius of curvature R2 of the edge of the second part is
1 / 2T <R2 <T
It is preferable that the relationship is satisfied. According to such a configuration, the edges of the first part and the second part are entirely arc-shaped. Therefore, since the external electrode covers the first and second main surfaces and the first and second side surfaces widely, the areas of the first portion and the second portion can be secured satisfactorily, and structural defects can be further suppressed.

  According to the present invention, structural defects can be suppressed and the occurrence of cracks can be reduced.

It is a perspective view which shows the multilayer electronic component which concerns on one Embodiment. It is the figure which looked at the multilayer electronic component shown in FIG. 1 from the main surface side. It is the figure which looked at the multilayer electronic component shown in FIG. 1 from the side surface side. It is a figure explaining the cross-sectional structure along the IV-IV line in FIG. FIG. 2 is an exploded perspective view of the multilayer electronic component shown in FIG. 1. It is sectional drawing which shows the mounting structure of a multilayer electronic component.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

  FIG. 1 is a perspective view showing a multilayer electronic component according to an embodiment. FIG. 2 is a view of the multilayer electronic component shown in FIG. 1 as viewed from the main surface side. FIG. 3 is a view of the multilayer electronic component shown in FIG. 1 as viewed from the side. FIG. 4 is a diagram for explaining a cross-sectional configuration along the line IV-IV in FIG. FIG. 5 is an exploded perspective view of the multilayer electronic component shown in FIG.

  As shown in FIGS. 1 to 4, the multilayer electronic component 1 is, for example, a multilayer capacitor, and an element body 2 configured in a substantially rectangular parallelepiped shape by stacking and integrating a plurality of plate-shaped ceramic green sheets. The external electrodes 3 and 4 are formed on both end surfaces of the element body 2. For example, the multilayer electronic component 1 has a length set to about 0.95 mm to 1.05 mm, a width set to about 0.45 mm to 0.55 mm, and a height set to about 0.10 mm to 0.33 mm. Has been.

  The element body 2 is a pair of first and second end faces 2a and 2b that face each other in the longitudinal direction of the element body 2 and that are parallel to each other, and that extends between the first and second end faces 2a and 2b and that faces each other. And a pair of first and second side surfaces 2e and 2f extending so as to connect the first and second main surfaces 2c and 2d and facing each other. The first and second end faces 2a and 2b, the first and second main faces 2c and 2d, and the first and second side faces 2e and 2f have a substantially rectangular shape.

  As shown in FIG. 5, the element body 2 is configured as a laminated body in which a plurality of rectangular plate-like dielectric layers 6, a plurality of internal electrodes 7, and internal electrodes 8 are stacked. The internal electrode 7 and the internal electrode 8 are arranged one by one in the element body 2 along the stacking direction of the dielectric layers 6, that is, in the opposing direction of the first and second main surfaces 2 c and 2 d. The internal electrode 7 and the internal electrode 8 are disposed so as to face each other with at least one dielectric layer 6 interposed therebetween. In the actual multilayer electronic component 1, the plurality of dielectric layers 6 are integrated to such an extent that the boundary between them cannot be visually recognized.

  The internal electrodes 7 and 8 include a conductive material such as Ni or Cu. The thickness of the internal electrodes 7 and 8 is, for example, about 1 μm to 5 μm. The internal electrodes 7 and 8 are not particularly limited as long as the internal electrodes 7 and 8 have shapes that overlap with each other when viewed from the stacking direction. For example, the internal electrodes 7 and 8 have a rectangular shape as shown in FIG. The internal electrodes 7 and 8 are configured as a sintered body of a conductive paste containing the conductive material. The internal electrode 7 is electrically connected to the external electrode 3, and the internal electrode 8 is electrically connected to the external electrode 4.

  The external electrode 3 covers the first end surface 2a, the first and second main surfaces 2c, 2d orthogonal to the first end surface 2a, and a part of each edge of the first and second side surfaces 2e, 2f. Is formed. That is, the external electrode 3 is disposed across the first end surface 2a, the first and second main surfaces 2c, 2d, and the first and second side surfaces 2e, 2f. The external electrode 4 covers the second end surface 2b, the first and second main surfaces 2c, 2d orthogonal to the second end surface 2b, and a part of each edge of the first and second side surfaces 2e, 2f. Is formed. That is, the external electrode 4 is disposed across the second end surface 2b, the first and second main surfaces 2c, 2d, and the first and second side surfaces 2e, 2f.

  The external electrodes 3 and 4 have a predetermined temperature (for example, about 700 ° C.) after a conductive paste mainly composed of Cu, Ni, Ag, Pd or the like is attached to the outer surface of the element body 2 by, for example, a dipping method. It is formed by baking with electroplating and further electroplating. For electroplating, Cu, Ni, Sn, or the like can be used.

  The external electrodes 3 and 4 have a first portion 10, a second portion 12, and a third portion 14. The first portion 10 is a portion located on each of the first and second main surfaces 2 c and 2 d of the element body 2. The second portion 12 is a portion that is continuous with the first portion 10 and is located on each of the first and second side surfaces 2 e and 2 f of the element body 2. The third portion 14 is a portion that is continuous with the first portion 10 and the second portion 12 and is located on the first or second end face 2 a, 2 b of the element body 2.

  Next, the configuration of the multilayer electronic component 1 will be described in detail. In the multilayer electronic component 1, the height dimension between the outer surfaces of the first portions 10 and 10 (the dimension in the opposing direction of the first and second main surfaces 2c and 2d) is “T”, and the second portions 12 and 12 The width dimension between the outer surfaces (dimensions in the opposing direction of the first and second side surfaces 2e, 2f) is defined as “W”. In the multilayer electronic component 1, the length dimension between the outer surfaces of the third portions 14 and 14 (the dimension in the opposing direction of the first and second end faces 2a and 2b) is set to “L”. The height dimension T is defined at a position where the thickness of the first portions 10 and 10 is maximized, and the width dimension W is defined at a position where the thickness of the second portions 12 and 12 is maximized. The length L is defined at a position where the thickness of the third portions 14 and 14 is maximum.

In the multilayer electronic component 1, the height dimension T, the width dimension W, and the length dimension L satisfy the following relationship.
T <L, W (1)
That is, in the multilayer electronic component 1, the height dimension T is smaller than the width dimension W and the length dimension L. That is, the multilayer electronic component 1 has a so-called low profile structure. The height dimension T of the multilayer electronic component 1 is less than 3/4 of the width dimension W (T <0.75 × W), preferably 1/3 of the width dimension W (T ≦ 0.3 × W) or less. It is.

  In the multilayer electronic component 1, the first portion 10 has a rectangular portion and a curved portion, and the rectangular portion and the curved portion are formed integrally. In the first portion 10, when viewed from the stacking direction, the curved portion is located on the inner side in the long side direction of the first and second main surfaces 2 c and 2 d than the rectangular portion.

  The curved portion of the first portion 10 is an end surface where the inner edge 10a in the facing direction of the first and second end surfaces 2a, 2b faces the end surface where the third portion 14 continuous with the first portion 10 is located. It has a convex arc shape on the side. The edge 10a has a predetermined radius of curvature R1. The curvature radius R1 is larger than the height dimension T of the multilayer electronic component 1 (R1> T), is 0.20 mm to 0.45 mm, and preferably 0.25 mm to 0.35 mm.

The edge 10a of the curved portion has ridges between the first and second main surfaces 2c and 2d and the first and second side surfaces 2e and 2f when viewed from the opposing direction of the first and second main surfaces 2c and 2d. It is a bending start point and a bending end point. Specifically, as shown in FIG. 2, the edge 10a of the first portion 10 located on the main surface 2c is, for example, a ridge portion between the first main surface 2c and the first side surface 2e serving as a curve start point. A ridge portion between the first principal surface 2c and the second side surface 2f is a bending end point. Thus, the entire edge 10a is formed in an arc shape when viewed from the stacking direction. That is, the radius of curvature R1 of the edge 10a satisfies the following relationship.
1 / 2W <R1 <W (2)

  The second part 12 has a rectangular part and a curved part, and the rectangular part and the curved part are integrally formed. In the second portion 12, the curved shape portion is located on the inner side in the long side direction of the first and second side surfaces 2 e and 2 f than the rectangular portion when viewed from the opposing direction of the first and second side surfaces 2 e and 2 f. ing.

  The curved portion of the second portion 12 is an end surface where the inner edge 12a in the facing direction of the first and second end surfaces 2a, 2b faces the end surface where the third portion 14 that is continuous with the second portion 12 is located. It has a convex arc shape on the side. The edge 12a has a predetermined radius of curvature R2.

The edge 12a of the curved portion is curved at the ridges between the first and second main surfaces 2c, 2d and the first and second side surfaces 2e, 2f when viewed from the opposing direction of the first and second side surfaces 2e, 2f. It is a starting point and a bending end point. Specifically, as shown in FIG. 3, the edge 12a of the second portion 12 located on the second side surface 2f is, for example, a ridge portion between the first main surface 2c and the second side surface 2f, and a curve start point. A ridge portion between the second main surface 2d and the second side surface 2f is a bending end point. Thereby, the edge 12a is formed in an arc shape as a whole when viewed from the opposing direction of the first and second side surfaces 2e, 2f. That is, the radius of curvature R2 of the edge 12a satisfies the following relationship.
1 / 2T <R2 <T (3)

In the multilayer electronic component 1, the height dimension T, the width dimension W, the radius of curvature R1 of the first portion 10 of the external electrodes 3 and 4, and the radius of curvature R2 of the second portion 12 satisfy the following relationship.
W> R1 (4)
T> R2 (5)
W / R1 <T / R2 (6)
That is, in the multilayer electronic component 1, the width dimension W is larger than the curvature radius R1 of the first portion 10, the height dimension T is larger than the curvature radius R2 of the second portion 12, and the width dimension W is the curvature radius R1. The divided value is smaller than the value obtained by dividing the height dimension T by the curvature radius R2.

  FIG. 6 is a cross-sectional view showing the mounting structure of the laminated electronic component. As shown in FIG. 6, the laminated electronic component 1 is embedded and mounted in a substrate 20. The substrate 20 is configured by laminating a plurality of insulating resin sheets 22 (here, five layers). The laminated electronic component 1 is disposed in the substrate 20, filled with a resin 23 and embedded in the substrate 20. The laminated electronic component 1 is electrically connected by electrodes 24 and 25 formed on the surface of the substrate 20 and via conductors 26 and 27.

  Specifically, a via conductor 26 is physically and electrically connected to the external electrode 3. At this time, since the area of the first portion 10 in the external electrode 3 is ensured, the connection between the external electrode 3 and the via conductor 26 can be reliably performed. Thereby, the external electrode 3 and the electrode 24 are electrically connected. A via conductor 27 is physically and electrically connected to the external electrode 4. At this time, since the area of the first portion 10 in the external electrode 4 is ensured, the connection between the external electrode 4 and the via conductor 27 can be reliably performed. Thereby, the external electrode 4 and the electrode 25 are electrically connected.

As described above, in the multilayer electronic component 1 of the present embodiment, the curvature radius R1 of the edge 10a of the first portion 10, the curvature radius R2 of the edge 12a of the second portion 12, the height dimension T, and the width dimension W are as follows.
W> R1
T> R2
W / R1 <T / R2
Meet the relationship. As described above, since the radius of curvature R1 of the edge 10a of the first portion 10 is set to be small, it is possible to distribute the stress applied to the element body 2. Thereby, generation | occurrence | production of the crack of the element | base_body 2 can be suppressed. Moreover, since the difference of the curvature radius R1 of the edge 10a with respect to the width dimension W is small, the area of the 1st part 10 arrange | positioned at the main surfaces 2c and 2d can be ensured, and structural defects, such as a crack and a chip | tip, can be suppressed.

  Moreover, in this embodiment, the curvature radius R1 of the edge 10a of the 1st part 10 is larger than the height dimension T, and is 0.20 mm-0.45 mm. Thus, since the area of the 1st part 10 can be ensured favorably by setting curvature radius R1 to 0.20 mm or more, structural defects, such as a crack and a chip, can be controlled. Further, by setting the radius of curvature R1 to 0.45 mm or less, the edge 10a has an arc shape with a large curvature, so that the stress can be more effectively dispersed and the occurrence of cracks can be further reduced.

  The present invention is not limited to the above embodiment. For example, in the above-described embodiment, a so-called low-profile multilayer electronic component having a small height dimension T of the multilayer electronic component 1 has been described as an example. However, the multilayer electronic component (element body 2) may have other shapes. Good.

  Moreover, in the said embodiment, although the multilayer capacitor was demonstrated to an example as a multilayer electronic component, a multilayer coil component etc. may be sufficient as a multilayer electronic component, for example.

  DESCRIPTION OF SYMBOLS 1 ... Laminated electronic component, 2 ... Element body, 2a, 2b ... End surface (1st and 2nd end surface), 2c, 2d ... Main surface (1st and 2nd main surface), 2e, 2f ... Side surface (1st 1 and second side), 3, 4 ... external electrode, 6 ... dielectric layer, 7,8 ... internal electrode, 10 ... first part, 10a ... edge, 12 ... second part, 12a ... edge, 14 ... Third part.

Claims (6)

A pair of end faces facing each other, a pair of main faces extending so as to connect between the pair of end faces, and a pair of side faces extending so as to connect between the pair of main faces and facing each other. An element body in which a plurality of dielectric layers and a plurality of internal electrodes are stacked in the opposing direction of the pair of main surfaces;
A pair of external electrodes disposed on each end face side of the element body and connected to the corresponding internal electrodes; and
Each of the external electrodes includes a first portion located on each main surface, a second portion continuing to the first portion and located on each side surface, and continuing to the first and second portions and A third portion located on the end face;
The first portion has an arcuate inner edge in the facing direction of the pair of end surfaces when viewed from the facing direction of the pair of main surfaces,
The second portion has an arcuate inner edge in the facing direction of the pair of end surfaces as viewed from the facing direction of the pair of side surfaces,
A radius of curvature R1 of the edge of the first portion, a radius of curvature R2 of the edge of the second portion, a dimension T between the outer surfaces of the first portion, and a dimension W between the outer surfaces of the second portion. But,
W> R1
T> R2
W / R1 <T / R2
A laminated electronic component characterized by satisfying the above relationship.   2. The multilayer electronic component according to claim 1, wherein a radius of curvature R <b> 1 of the edge of the first portion is 0.20 mm to 0.45 mm.   3. The multilayer electronic component according to claim 1, wherein a radius of curvature R <b> 1 of the edge of the first portion is larger than a dimension T between outer surfaces of the first portion.   The dimension T between the outer surfaces of the first part is smaller than the dimension W between the outer surfaces of the second part and the dimension between the outer surfaces of the third part. The laminated electronic component according to claim 3.   5. The dimension T between the outer surfaces of the first parts is less than 3/4 of the dimension W between the outer surfaces of the second parts. Laminated electronic components. The radius of curvature R1 of the edge of the first portion is:
1 / 2W <R1 <W
And the radius of curvature R2 of the edge of the second portion is
1 / 2T <R2 <T
The multilayer electronic component according to claim 1, wherein the relationship is satisfied.

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