JP6641935B2 - Electronic components - Google Patents

Description

  The present invention relates to an electronic component.

  BACKGROUND ART Conventionally, electronic components such as a capacitor, an inductor, a piezoelectric element, a varistor or a thermistor have been known.

  For example, Patent Literature 1 below discloses a multilayer capacitor. Patent Literature 1 specifically describes a two-terminal vertical multilayer capacitor (that is, stacked internal electrodes in a capacitor are arranged vertically on a mounting surface of a circuit board, and terminals of two capacitors connected to the circuit board). ).

  In the capacitor disclosed in Patent Document 1, a pair of external electrodes and an insulating layer that completely covers a region between the pair of external electrodes are provided on a surface facing the circuit board.

JP 2013-46052 A

  For example, when water enters the element body during manufacturing or driving of an electronic component, characteristic degradation due to erosion of the internal electrode or the like is caused, and thus the electronic component is required to have sufficiently high moisture resistance. In the above-described conventional capacitor, there is a risk that water may enter the element body at the interface between the external electrode and the insulating layer on the surface facing the circuit board.

  Therefore, the inventors have repeatedly studied the intrusion of water into the element body, and as a result, have newly found a structure of an electronic component capable of improving the moisture resistance.

  That is, an object of the present invention is to provide an electronic component with improved moisture resistance.

  The electronic component according to the present invention is provided with a base body, a plurality of extraction electrodes located inside the base body and exposing end faces from one surface of the base body, and provided on one surface of the base body, An electrode layer that is in contact with the first portion of the end surface of the extraction electrode exposed on one surface, and a first electrode that is provided on one surface of the element body so as to be in contact with the electrode layer and that is adjacent to the first portion of the end surface of the extraction electrode. 2 and an insulating layer in contact with the portion, and a portion of the electrode layer in contact with the insulating layer rides on the insulating layer.

  According to the above electronic component, the route of entry of water passing through the interface between the electrode layer and the insulating layer is extended because the electrode layer rides on the insulating layer in a portion in contact with the insulating layer. Thereby, infiltration of water into the element body is effectively suppressed, and improvement in moisture resistance is achieved.

  Further, the plurality of extraction electrodes extend in parallel with each other, and when viewed from the normal direction of the surface on which the plurality of extraction electrodes extend, there is a region where the plurality of extraction electrodes overlap with each other; The length of the end face from which the extraction electrode is exposed from one surface of the element body may be longer than the length of the electrode layer. In this case, the shortest route of the current flowing between the pair of electrode layers is shortened, and the equivalent series inductance (ESL) is reduced.

  Further, the insulating layer may have a mode in which the end surface is inclined and the surface in contact with one surface of the element body is wider than the surface on the other side. In this case, in this case, it becomes difficult to form a gap near the end face of the insulating layer, which is a starting point of a crack or the like.

  According to various aspects of the invention, an electronic component with improved moisture resistance is provided.

FIG. 1 is a schematic perspective view of a multilayer capacitor according to an embodiment. FIG. 2 is a sectional view taken along line II-II of the multilayer capacitor shown in FIG. FIG. 2 is a sectional view taken along line III-III of the multilayer capacitor shown in FIG. FIG. 4 is an enlarged view of a main part of the cross-sectional view shown in FIG. FIG. 5 is a cross-sectional view illustrating a multilayer capacitor according to the related art. FIG. 6 is a cross-sectional view showing an insulating layer and an electrode layer in a mode different from the mode shown in FIG. FIG. 7 is a cross-sectional view showing an insulating layer and an electrode layer in a mode different from the mode shown in FIG. FIG. 8 is a diagram illustrating an insulating layer and an electrode layer in a mode different from the mode illustrated in FIG. 4. FIG. 9 is a diagram illustrating an insulating layer and an electrode layer in a mode different from the mode illustrated in FIG. 4. FIG. 10 is a cross-sectional view showing a multilayer capacitor in a different mode.

  Hereinafter, an electronic component according to an embodiment will be described in detail with reference to the accompanying drawings. In the description, the same elements or elements having the same functions will be denoted by the same reference symbols, without redundant description.

  FIG. 1 shows a multilayer capacitor 10 as an electronic component according to the embodiment. As shown in FIG. 1, the multilayer capacitor 10 includes a body 20 having a substantially rectangular parallelepiped outer shape. The element body 20 has a pair of end surfaces 20a and 20b facing each other, and extends so as to be orthogonal to the both end surfaces 20a and 20b, and has a bottom surface (one surface) 20c connecting the both end surfaces 20a and 20b. Have. The dimensions of the element body 20 are, for example, a length (a distance between both end faces 20a and 20b) of 600 μm and a width (a direction perpendicular to the direction in which the both end faces 20a and 20b face each other and the normal direction of the bottom face 20c). ) Is 300 μm and the height is 300 μm, but is not limited thereto. The dimensions of the element body 20 are preferably such that the length is 1000 μm or less, the width is 500 μm or less, and the height is 500 μm or less.

  A plurality of capacitor internal electrodes 22 and 24 are formed inside the element body 20. Each of the capacitor internal electrodes 22 and 24 extends along the direction in which the end surfaces 20a and 20b are opposed to each other in a posture standing upright with respect to the bottom surface 20c of the element body 20. The plurality of capacitor internal electrodes 22 and 24 are stacked parallel to each other at a predetermined distance. That is, the plurality of capacitor internal electrodes 22 and 24 are stacked so as to be orthogonal to the facing direction of the end surfaces 20a and 20b of the element body 20 and the normal direction of the bottom surface 20c.

  The plurality of capacitor internal electrodes 22, 24 are composed of a positive electrode internal electrode 22 and a negative electrode internal electrode 24, and the positive electrode internal electrodes 22 and the negative electrode internal electrodes 24 are alternately arranged. Each of the internal electrodes 22 and 24 has integrally formed capacitor electrodes 22a and 24a for mainly forming a capacitor and extraction electrodes 22b and 24b for mainly extracting the electrodes to the outside of the element body. . Specifically, as shown in FIG. 2, the internal electrode 24 includes a rectangular capacitor electrode 24 a extending long in a direction opposite to the element body end surfaces 20 a and 20 b (the left-right direction in FIG. 2), and a bottom surface 20 c of the capacitor electrode 24 a. And a rectangular extraction electrode 24b provided on the side and exposed on the bottom surface 20c. The extraction electrode 24b extends from near the end face 20b to near the center of the bottom face 20c along the bottom face 20c. The other internal electrode 22 also includes a capacitor electrode 22a having substantially the same dimensions as the capacitor electrode 24a of the internal electrode 24, and a rectangular extraction electrode 22b provided on the bottom surface 20c side of the capacitor electrode 22a and exposed on the bottom surface 20c. Having.

  The dimensions of the capacitance electrodes 22a and 24a are, for example, 500 μm in length, 200 μm in height, and 1 μm in thickness. The dimensions of the extraction electrodes 22b and 24b are, for example, 200 μm in length, 50 μm in height, and 1 μm in thickness.

  The pair of electrode layers 30A and 30B and the insulating layer 40 are formed on the bottom surface 20c of the element body 20. As shown in FIGS. 1 to 3, the pair of electrode layers 30 </ b> A and 30 </ b> B and the insulating layer 40 are formed over the entire length in the width direction of the bottom surface 20 c (that is, in the laminating direction of the internal electrodes 22 and 24).

  The pair of electrode layers 30A and 30B are connected to the internal electrodes 22 and 24 described above. Specifically, the electrode layer 30A of the positive electrode is provided in the bottom surface region on the side of the end surface 20a, and is in contact with a part of the end surface 23 of the extraction electrode 22b of each internal electrode 22 exposed on the bottom surface 20c, thereby forming the electrode layer 30A. And each internal electrode 22 are electrically connected. The negative electrode layer 30B is provided in the bottom surface region on the side of the end surface 20b, and is in contact with a part of the end surface 25 of the extraction electrode 24b of each internal electrode 24 exposed on the bottom surface 20c, whereby the electrode layer 30B and each internal electrode 24 Are electrically connected.

  The insulating layer 40 is provided in a central region of the bottom surface 20c so as to cover a region between the pair of electrode layers 30A and 30B. As shown in FIG. 2, the insulating layer 40 is in contact with both of the pair of electrode layers 30A and 30B, is in contact with a part of the end face 23 of the lead electrode 22b of each internal electrode 22 exposed on the bottom face 20c, and In contact with a part of the end face 25 of the extraction electrode 24b of each internal electrode 24 exposed to the outside.

  Here, the positional relationship among the extraction electrodes 22b and 24b, the electrode layers 30A and 30B, and the insulating layer 40 will be described in more detail with reference to FIG.

  As shown in FIG. 4, each of the electrode layers 30 </ b> A and 30 </ b> B is designed to be thicker than the insulating layer 40, and rides on the insulating layer 40 at a portion in contact with the insulating layer 40. It can also be said that the portion of the insulating layer 40 that is in contact with the electrode layers 30A, 30B is buried under the electrode layers 30A, 30B (on the bottom surface 20c side). As a result, in the extraction electrode 24b, the first portion 25a of the end face 25 contacts the electrode layer 30B, and the second portion 25b of the end face 25 adjacent to the left side of the first portion 25a contacts the insulating layer 40. Become. The extraction electrode 22b also contacts the electrode layer 30B at the first portion of the end face 23, and contacts the insulating layer 40 at the second portion of the end face 23 adjacent to the right side of the first portion 25a.

  As described above, when each of the electrode layers 30A and 30B rides on the insulating layer 40 at a portion in contact with the insulating layer 40, the interface between the electrode layers 30A and 30B and the insulating layer 40 as shown in FIG. Is bent. Thereby, as compared with the case where the electrodes 130A, 130B and the insulating layer 140 having the same thickness are simply arranged side by side on the bottom surface 120c of the element body 120 as in the multilayer capacitor shown in FIG. 5, a straight interface is formed. Thus, in the multilayer capacitor 10, the interface between the electrode layers 30A and 30B and the insulating layer 40 is extended.

  Therefore, when water intrudes into the element body 20 of the multilayer capacitor 10 from the outside, the infiltration route (arrow R1 in FIG. 4) is greater than the infiltration route (arrow R2 in FIG. 5) in the configuration of FIG. , The length is increased by the amount of bypassing the insulating layer 40.

  As described above, the electronic component 10 includes the element body 20 and the plurality of extraction electrodes 22 b and 24 b positioned inside the element body 20 and exposing the end faces 23 and 25 from the bottom surface 20 c of the element body 20. The electrode layers 30A and 30B provided on the bottom surface 20c of the body 20 and in contact with the first portions 23a and 25a of the end surfaces 23 and 25 of the extraction electrodes 22b and 24b exposed on the bottom surface 20c, and the electrode layers 30A and 30B on the bottom surface 20c. An insulating layer 40 provided in contact with the first portions 23a and 25a and in contact with the second portions 23b and 25b adjacent to the first portions 23a and 25a, and a portion of the electrode layers 30A and 30B in contact with the insulating layer 40 is formed of an insulating layer. I am on 40.

  In such a multilayer capacitor 10, high moisture resistance is realized by a long water intrusion route into the element body 20 and effective suppression of water intrusion.

In the multilayer capacitor 10, the direction in which the internal electrodes 22 and 24 are stacked is not the height direction of the element body 20 but the direction parallel to the bottom surface 20 c that is the electrode formation surface.
In the multilayer capacitor stacked along the height direction of the element body 20, the length of the current route passing through the upper internal electrode is shorter than the length of the current route passing through the lower internal electrode near the electrode forming surface. Since the length is long, the internal electrodes in the upper layer in particular cause an increase in the equivalent series inductance (ESL). On the other hand, in the multilayer capacitor 10, a current flowing between the electrode layers 30A and 30B can flow at a position relatively close to the bottom surface 20c of each of the internal electrodes 22 and 24. That is, the shortest route of the current flowing between the pair of electrode layers 30A and 30B is the same for each of the internal electrodes 22 and 24 of the multilayer capacitor 10, and the shortest route is relatively short. Therefore, in the multilayer capacitor 10 in which the lamination direction of the internal electrodes 22 and 24 is parallel to the bottom surface 20c, a low equivalent series inductance (ESL) is realized.

  Note that the dimensions and shapes of the electrode layers 30A and 30B and the insulating layer 40 can be variously changed as long as the interface length is increased. Hereinafter, an insulating layer 40 different from the above-described insulating layer 40 will be described.

  The insulating layer 41 shown in FIG. 6 is the same as the above-described insulating layer 40 except that both end faces 41a in contact with the electrode layers 30A and 30B are inclined. The surface of the insulating layer 41 that is in contact with the bottom surface 20c of the element body 20 is wider than the other surface because the both end surfaces 41a are inclined. Also in such an insulating layer 41, similarly to the above-described insulating layer 40, the interface between the electrode layers 30A and 30B and the insulating layer 41 is extended, and when water enters from outside, the infiltration route is extended. I have.

  In addition, according to the configuration of the insulating layer 41, the following additional effects can be obtained.

  That is, at the time of manufacturing, it is conceivable that the insulating layer 41 is formed on the bottom surface 20c of the element body 20, and then the electrode layers 30A and 30B are formed so as to cover the vicinity of the end face 41a of the insulating layer 41. At this time, in the insulating layer 41 in which the surface in contact with the bottom surface 20c is wider than the surface on the other side, the angle θ1 of the corner defined by the end surface 41a and the bottom surface 20c is obtuse. Sometimes, the electrode material easily enters the corners. In other words, a situation in which the electrode material does not enter the corner portion when the electrode is formed and a gap is generated is significantly avoided. Such a void tends to be a starting point of a crack generated near the end face of the insulating layer.

  Therefore, since the insulating layer 41 has the inclined end surface 41a as described above, it is possible to effectively suppress the occurrence of cracks that occur in the multilayer capacitor 10. As a result, the moisture resistance is further improved.

  Note that, like the insulating layer 40 shown in FIG. 7, the end surface 40b in the width direction may be inclined so that the surface in contact with the bottom surface 20c of the element body 20 is wider than the surface on the other side. Also in this case, a situation in which a void is generated near the end face 40b is significantly avoided, and the occurrence of cracks in the multilayer capacitor 10 can be effectively suppressed.

  Note that, as in the insulating layer 42 shown in FIG. 8, both end surfaces 42 a that are in contact with the electrode layers 30 A and 30 B are inclined such that the surface that contacts the bottom surface 20 c of the element body 20 is narrower than the other surface. It can also be done. In the insulating layer 42 as well, similarly to the above-described insulating layer 40, the interface between the electrode layers 30A and 30B and the insulating layer 42 is extended, and when water enters from the outside, the infiltration route is extended. I have.

  At the time of manufacturing, a procedure of forming the electrode layers 30A and 30B in, for example, two steps may be adopted so that no void is generated in the corner defined by the end face 42a and the bottom face 20c.

  That is, first, the first stage 30a of the electrode layers 30A and 30B is formed on the bottom surface 20c of the element body 20. Then, an insulating layer 42 having the same height as the first stage 30a of the electrode layers 30A and 30B is formed. At this time, since the angle θ2 of the corner defined by the first end face of the electrode layers 30A and 30B and the bottom surface 20c is an obtuse angle, the material of the insulating layer 42 easily enters the corner. Thereafter, a first stage 30a covering the end portions of the insulating layer 42 and a first stage 30a of the electrode layers 30A and 30B are formed. As a result, the insulating layer 42 having the shape shown in FIG. 7 can be formed while suppressing the occurrence of a gap.

  In the insulating layer 43 shown in FIG. 9, the surface 43a opposite to the surface in contact with the bottom surface 20c of the element body 20 is entirely curved, and the thickness D1 near the center is the thickness near the end. It is thicker than D2. Also in such an insulating layer 43, similarly to the above-described insulating layer 40, the interface between the electrode layers 30A and 30B and the insulating layer 41 is extended, and when water intrudes from the outside, the infiltration route is extended. I have.

  Further, the dimensions and shapes of the extraction electrodes 22b and 24b of the internal electrodes 22 and 24 can be variously changed.

  In FIG. 10, the extraction electrode 22b of the internal electrode 22 and the extraction electrode 24b of the internal electrode 24 overlap each other when viewed from the lamination direction of the internal electrodes (the normal direction of the surface on which the extraction electrode extends). FIG.

  Specifically, the length of the end face 25 of the extraction electrode 24b is longer than the length of the electrode layer 30B, and the extraction electrode 24b extends along the bottom surface 20c from the vicinity of the end face 20b to a position reaching above the electrode layer 30A. . The length of the end face 23 of the extraction electrode 22b is also longer than the length of the electrode layer 30A, and the extraction electrode 22b also extends along the bottom surface 20c from near the end face 20a to a position reaching above the electrode layer 30B. As a result, a region A is formed in which the extraction electrodes 22b and 24b overlap each other when viewed from the lamination direction of the internal electrodes.

  In this case, a current route flowing between the pair of electrode layers 30A and 30B is formed in the region A where the internal electrodes 22 and 24 overlap, so that the current route is shortened and the equivalent series inductance (ESL) is reduced. Further reductions are realized. In addition, since the extraction electrodes 22b and 24b in the overlapping region A function as capacitance electrodes, the capacitance can be increased.

  Note that the present invention is not limited to the above embodiment, and various modifications are possible. For example, the electronic component is not limited to a capacitor, but may be an inductor, a piezoelectric element, a varistor, a thermistor, or the like.

  Reference Signs List 10 laminated capacitor, 20, 120 elementary body, 20c, 120c bottom surface, 22, 24, 122, 124 internal electrode, 23, 25 end surface, 23a, 25a first portion, 23b, 25b second , 30A, 30B, 130A, 130B ... electrode layer, 40, 41, 42, 43, 140 ... insulating layer, R1, R2 ... penetration route.

Claims (5)

Prime field,
A plurality of extraction electrodes, which are located inside the element body and whose end faces are exposed from one surface corresponding to the mounting surface of the circuit board of the element body,
An electrode layer provided on the one surface of the element body and in contact with a first portion of an end face of the extraction electrode exposed on the one surface of the element body;
An insulating layer provided on the one surface of the element body so as to be in contact with the electrode layer, and in contact with a second portion adjacent to the first portion on an end surface of the extraction electrode;
An electronic component, wherein a portion of the electrode layer that is in contact with the insulating layer runs on the insulating layer. Further comprising a plurality of internal electrodes formed inside the element body and having the extraction electrode, wherein each of the internal electrodes extends in a direction orthogonal to the one surface of the element body. Item 2. The electronic component according to Item 1. The electronic component according to claim 2, wherein the plurality of internal electrodes include a positive electrode internal electrode and a negative electrode internal electrode. The plurality of extraction electrodes extend parallel to each other,
When viewed from the normal direction of the surface on which the plurality of extraction electrodes extend, there is a region where the plurality of extraction electrodes overlap each other, and the plurality of extraction electrodes are exposed from one surface of the element body. 4. The electronic component according to claim 1, wherein a length of the end surface to be formed is longer than a length of the electrode layer. 5. 5. The electron according to claim 1, wherein an end surface of the insulating layer is inclined, and a surface in contact with one surface of the element body is wider than a surface on the other side. 6. parts.

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