Electronic components and methods for manufacturing electronic components

Abstract

This invention provides an electronic component that suppresses the occurrence of cracks in the conductive resin layer. [Solution] The electronic component includes a base body 3 and an external electrode 5 disposed on the base body 3. The external electrode 5 includes a second electrode layer E2 and a plating layer PL formed on the second electrode layer E2. The external electrode 5 has a hole 5h formed from the surface of the plating layer PL and reaching the second electrode layer E2.

Description

Technical Field

[0001] One aspect of the present invention relates to an electronic component. Another aspect of the present invention relates to a method for manufacturing an electronic component.

Background Art

[0002] Known electronic components include a body and external electrodes disposed on the body. The external electrodes include, for example, a conductive resin layer and a plating layer formed on the conductive resin layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The conductive resin layer generally includes a plurality of conductive particles and a resin. The resin tends to absorb moisture. When the electronic component is heated, the moisture absorbed by the resin may gasify and expand in volume. In this case, stress may act on the conductive resin layer, and cracks may occur in the conductive resin layer. For example, when the electronic component is soldered to an electronic device, the electronic component is heated. The electronic device includes, for example, a circuit board or an electronic component.

[0005] One aspect of the present invention aims to provide an electronic component that suppresses the occurrence of cracks in the conductive resin layer. Another aspect of the present invention aims to provide a method for manufacturing an electronic component that suppresses the occurrence of cracks in the conductive resin layer.

Means for Solving the Problems

[0006] An electronic component according to one aspect of the present invention includes a base body and an external electrode disposed on the base body, which includes a conductive resin layer and a plating layer formed on the conductive resin layer. The external electrode has a hole formed from the surface of the plating layer and reaching the conductive resin layer.

[0007] In one of the above embodiments, the holes in the external electrode are formed from the surface of the plating layer and reach the conductive resin layer. When the electronic component is heated, even if the moisture absorbed by the resin gasifies, the gas generated from the moisture moves outside the external electrode through the holes. In other words, the holes form a gas movement path. Therefore, stress is less likely to act on the conductive resin layer. As a result, this embodiment suppresses the occurrence of cracks in the conductive resin layer.

[0008] In one of the above embodiments, the plating layer may include an undercoat plating layer and a solder plating layer placed on the undercoat plating layer. The inner diameter of the holes in the solder plating layer may be larger than the inner diameter of the holes in the undercoat plating layer. When electronic components are soldered into electronic devices, the solder plating layer becomes wet with molten solder. In this case, the molten solder may clog the holes. In a configuration where the inner diameter of the holes in the solder plating layer is larger than the inner diameter of the holes in the undercoat plating layer, even if the solder plating layer is wetted by molten solder, the molten solder is less likely to block the holes. Therefore, this configuration reliably suppresses the occurrence of cracks in the conductive resin layer even when electronic components are soldered into electronic devices.

[0009] In one embodiment described above, the conductive resin layer may include a first portion that includes the position of maximum thickness in the conductive resin layer, and a second portion having a thickness less than that of the first portion. The hole may extend to the first portion. The first part has a greater thickness than the second part. Therefore, the first part may absorb more moisture than the second part. In a configuration where the hole reaches the first portion, the hole forms a gas migration path from the first portion. Gas generated from moisture absorbed in the first portion reliably moves outside the external electrode through the hole. Therefore, stress is less likely to act on the first portion of the conductive resin layer. This configuration reliably suppresses the occurrence of cracks in the conductive resin layer.

[0010] In one of the above embodiments, the base body may include an end face, and the external electrodes may be located on the end face. The conductive resin layer may include a first portion located on the central region of the end face and a second portion located on the outer peripheral region of the end face. The hole may extend to the first portion. The conductive resin layer is formed, for example, by curing a conductive resin paste. The conductive resin paste contains, for example, a curable resin and an organic solvent. The organic solvent vaporizes. The vaporization of the organic solvent generates gas within the conductive resin paste. The gas generated by the vaporization of the organic solvent travels directly from any point in the conductive resin paste where the organic solvent is present to the surface of the conductive resin paste and escapes from the conductive resin paste. As a result of the vaporization of the organic solvent, voids are formed in each of the aforementioned points within the conductive resin paste, serving as pathways for the gas. In other words, the conductive resin layer tends to contain multiple voids. The inventors have newly discovered that when a conductive resin layer is formed from a conductive resin paste, the first portion tends to contain more voids than the second portion. In a configuration where the holes reach the first portion, the holes easily connect to the voids that are abundant in the first portion. Gases generated from moisture absorbed by the first portion travel from the voids to the holes. Therefore, gases generated from moisture are more easily transported outside the external electrodes. Stress is less likely to act on the conductive resin layer. This configuration further suppresses the occurrence of cracks in the conductive resin layer.

[0011] In one of the above embodiments, the hole may extend into the conductive resin layer. In a configuration where the holes extend into the conductive resin layer, gases generated from moisture can easily reach the holes. Therefore, stress is less likely to act on the conductive resin layer. As a result, the above-described embodiment further suppresses the occurrence of cracks in the conductive resin layer.

[0012] A method for manufacturing an electronic component according to another aspect of the present invention includes preparing a substrate on which an external electrode is formed, comprising a conductive resin layer and a plating layer formed on the conductive resin layer, and forming a hole in the external electrode that reaches from the surface of the plating layer to the conductive resin layer.

[0013] In one of the other embodiments described above, holes are formed in the external electrodes on the prepared substrate, extending from the surface of the plating layer to the conductive resin layer. As described above, these holes form gas transfer paths generated from moisture. Therefore, in the electronic component obtained from this other embodiment, stress is less likely to act on the conductive resin layer. As a result, this other embodiment provides an electronic component that suppresses the occurrence of cracks in the conductive resin layer.

[0014] In one of the other embodiments described above, forming a hole may include forming the hole so as to reach into the conductive resin layer. If forming a hole involves forming the hole so that it reaches into the conductive resin layer, then in the resulting electronic component, as described above, gases generated from moisture can easily reach the hole formed in the external electrode. In this case, the resulting electronic component is less susceptible to stress acting on the conductive resin layer, and the occurrence of cracks in the conductive resin layer is further suppressed.

[0015] In one of the other embodiments described above, forming the holes may include irradiating the surface of the plating layer with a laser. If forming a hole involves irradiating the surface of the plating layer with a laser, the hole is formed by the laser irradiation. Therefore, a hole reaching from the surface of the plating layer to the conductive resin layer can be formed easily and reliably. [Effects of the Invention]

[0016] One aspect of the present invention provides an electronic component that suppresses the generation of cracks in a conductive resin layer. Another aspect of the present invention provides a method for manufacturing an electronic component that suppresses the generation of cracks in a conductive resin layer.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is a perspective view of a multilayer capacitor according to an embodiment. [Figure 2] FIG. 2 is a diagram showing a cross-sectional configuration of the multilayer capacitor. [Figure 3] FIG. 3 is a diagram showing a cross-sectional configuration of the multilayer capacitor. [Figure 4] FIG. 4 is a plan view showing an end face. [Figure 5] FIG. 5 is a diagram showing a planar configuration of an external electrode. [Figure 6] FIG. 6 is a diagram showing a cross-sectional configuration of the external electrode. [Figure 7] FIG. 7 is a diagram showing a planar configuration of the external electrode. [Figure 8] FIG. 8 is a diagram showing a cross-sectional configuration of the external electrode. [Figure 9] FIG. 9 is a schematic diagram showing a manufacturing process of the multilayer capacitor. [Figure 10] FIG. 10 is a diagram showing a cross-sectional configuration of an electronic component device according to another embodiment. [Figure 11] FIG. 11 is a diagram showing a planar configuration of an external electrode and a solder fillet.

Embodiments of the Invention

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals will be used for the same elements or elements having the same function, and redundant descriptions will be omitted.

[0019] The configuration of the multilayer capacitor C1 according to this embodiment will be described with reference to Figures 1 to 6. Figure 1 is a perspective view of the multilayer capacitor according to this embodiment. Figures 2 and 3 are diagrams showing the cross-sectional configuration of the multilayer capacitor according to this embodiment. Figure 4 is a plan view showing the end face. Figure 5 is a diagram showing the plan configuration of the external electrodes. Figure 6 is a diagram showing the cross-sectional configuration of the external electrodes. In Figure 6, the hatching indicating the cross-section is omitted. The electronic components include, for example, a multilayer capacitor C1.

[0020] As shown in Figure 1, the multilayer capacitor C1 includes a rectangular parallelepiped base body 3 and a plurality of external electrodes 5. The multilayer capacitor C1 includes, for example, a pair of external electrodes 5. The pair of external electrodes 5 are arranged on the outer surface of the base body 3. The pair of external electrodes 5 are spaced apart from each other. The rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and edges, or a rectangular parallelepiped shape with rounded corners and edges.

[0021] Body 3 includes four sides 3a and a pair of opposite end faces 3e. The four sides 3a and the pair of end faces 3e are rectangular in shape. Each of the four sides 3a includes a pair of opposite sides 3a and another pair of opposite sides 3a. The direction in which the pairs of sides 3a face each other is direction D2. The direction in which the other pair of sides 3a face each other is direction D3. The direction in which the pair of end faces 3e face each other is direction D1. The multilayer capacitor C1 is soldered to an electronic device. The electronic device includes, for example, a circuit board or another electronic component. In the multilayer capacitor C1, one of the four sides 3a faces the electronic device. One side 3a is positioned to constitute the mounting surface. One side 3a is the mounting surface.

[0022] Direction D2 is perpendicular to a pair of sides 3a and perpendicular to direction D3. Direction D1 is parallel to one pair of sides 3a and another pair of sides 3a and perpendicular to directions D2 and D3. Direction D3 is perpendicular to another pair of sides 3a, and direction D1 is perpendicular to each end face 3e. The length of the element 3 in direction D1 is, for example, greater than the length of the element 3 in direction D2 and greater than the length of the element 3 in direction D3. Direction D1 is the longitudinal direction of the element 3. The length of the element 3 in direction D2 and the length of the element 3 in direction D3 may be equal to each other. The length of the element 3 in direction D2 and the length of the element 3 in direction D3 may be different to each other.

[0023] The length of base body 3 in direction D2 is the height of base body 3. The length of base body 3 in direction D3 is the width of base body 3. The length of base body 3 in direction D1 is the length of base body 3. For example, the height of base body 3 is 0.1 to 3.2 mm, the width of base body 3 is 0.1 to 6.3 mm, and the length of base body 3 is 0.2 to 7.5 mm. For example, the height of base body 3 is 1.25 mm, the width of base body 3 is 1.25 mm, and the length of base body 3 is 2.0 mm.

[0024] A pair of sides 3a extend in direction D3 to connect another pair of sides 3a. A pair of sides 3a also extends in direction D1. Another pair of sides 3a extends in direction D2 to connect another pair of sides 3a. Another pair of sides 3a also extends in direction D1. A pair of end faces 3e extend in direction D2 to connect another pair of sides 3a. A pair of end faces 3e extend in direction D3 to connect another pair of sides 3a.

[0025] The base body 3 includes a ridge located between the end face 3e and the side surface 3a, and a ridge located between one of a pair of side surfaces 3a and one of another pair of side surfaces 3a. For example, each ridge is rounded to curve. The base body 3 is subjected to so-called R-chamfering. The end face 3e and the side surface 3a are indirectly adjacent via the ridge located between the end face 3e and the side surface 3a. One of a pair of side surfaces 3a and one of another pair of side surfaces 3a are indirectly adjacent via the ridge located between one of a pair of side surfaces 3a and one of another pair of side surfaces 3a.

[0026] The base body 3 is constructed by stacking multiple dielectric layers in direction D2. The base body 3 includes multiple stacked dielectric layers. In the base body 3, the stacking direction of the multiple dielectric layers coincides with direction D2. Each dielectric layer is composed of, for example, a sintered body of a ceramic green sheet containing a dielectric material. The dielectric material includes dielectric ceramics. Dielectric ceramics include, for example, BaTiO3 systems, Ba(Ti,Zr)O3 systems, or (Ba,Ca)TiO3 systems. In the actual base body 3, each dielectric layer is integrated to such an extent that the boundaries between each dielectric layer are not visible.

[0027] The multilayer capacitor C1 includes a plurality of internal electrodes 7, as shown in Figure 2. Each internal electrode 7 is an internal conductor located within the element 3. Each internal electrode 7 is made of a conductive material commonly used as an internal conductor in multilayer electronic components. The conductive material includes, for example, a base metal. The conductive material includes, for example, nickel (Ni) or copper (Cu). The internal electrode 7 is constructed as a sintered body of a conductive paste containing the above conductive material. For example, the internal electrode 7 is made of nickel.

[0028] Multiple internal electrodes 7 are arranged in different positions (layers) in direction D2. Multiple internal electrodes 7 are arranged in the base body 3 so as to be spaced apart and facing each other in direction D2. Adjacent internal electrodes 7 in direction D2 have different polarities. One end of an internal electrode 7 is exposed to the corresponding end face 3e of a pair of end faces 3e. An internal electrode 7 includes one end that is exposed to the corresponding end face 3e. Multiple internal electrodes 7 include an internal electrode 7 exposed to one end face 3e of a pair of end faces 3e and an internal electrode 7 exposed to the other end face 3e of a pair of end faces 3e. The internal electrodes 7 exposed to one end face 3e and the internal electrodes 7 exposed to the other end face 3e are arranged alternately in direction D2. Multiple internal electrodes 7 are arranged in the base body 3 so as to be aligned in direction D2. The internal electrodes 7 are located in a plane substantially parallel to a pair of side surfaces 3a. The direction in which the internal electrodes 7 face each other (direction D2) is perpendicular to the direction parallel to the pair of side surfaces 3a (directions D3 and D1).

[0029] When the stacking direction of multiple dielectric layers is direction D3, the multiple internal electrodes 7 are arranged at different positions (layers) in direction D3. When the stacking direction of multiple dielectric layers is direction D3, the internal electrodes 7 exposed on one end face 3e and the internal electrodes 7 exposed on the other end face 3e are arranged alternately in direction D3. The internal electrodes 7 are located in a plane substantially parallel to another pair of side surfaces 3a. The internal electrodes 7 face each other in direction D3.

[0030] The external electrodes 5 are located at both ends of the body 3 in direction D1, as shown in Figure 1. Each external electrode 5 is located on the corresponding end face 3e side of the body 3. For example, each external electrode 5 is located on four sides 3a and one end face 3e. Each external electrode 5 is located on the corresponding end face 3e. The external electrode 5 includes multiple electrode portions 5a, 5e, as shown in Figures 2 and 3. Electrode portion 5a is located on the side 3a and on the ridge between the side 3a and the end face 3e. Electrode portion 5e is located on the end face 3e. The external electrode 5 also includes electrode portions located on the ridge between adjacent side 3a. Hereinafter, the ridge between the side 3a and the end face 3e will be referred to as the first ridge, and the ridge between adjacent side 3a will be referred to as the second ridge.

[0031] The external electrode 5 is formed on five surfaces: four side surfaces 3a and one end surface 3e, as well as on the edges. Adjacent electrode portions 5a and 5e are physically connected and electrically connected. Electrode portion 5e covers one end of a corresponding internal electrode 7 among a plurality of internal electrodes 7. Electrode portion 5e is directly connected to the corresponding internal electrode 7. The external electrode 5 is electrically connected to the corresponding internal electrode 7. The external electrode 5 includes a first electrode layer E1, a second electrode layer E2, a third electrode layer E3, and a fourth electrode layer E4, as shown in Figures 2 to 4. The fourth electrode layer E4 is the outermost layer of the external electrode 5. Each electrode portion 5a, 5e includes the first electrode layer E1, the second electrode layer E2, the third electrode layer E3, and the fourth electrode layer E4.

[0032] The first electrode layer E1 of electrode portion 5a is positioned on the first edge and not on the side surface 3a. The first electrode layer E1 of electrode portion 5a covers the entire first edge. The first electrode layer E1 does not cover the side surface 3a. The first electrode layer E1 of electrode portion 5a is in contact with the first edge. The side surface 3a is exposed from the first electrode layer E1. The first electrode layer E1 of electrode portion 5a may be positioned on the side surface 3a. In this case, the first electrode layer E1 of electrode portion 5a covers a portion of the side surface 3a and the entire first edge. That is, the first electrode layer E1 of electrode portion 5a is in contact with the aforementioned portion of the side surface 3a. The aforementioned portion covered by the first electrode layer E1 of electrode portion 5a is located closer to the end surface 3e. The second electrode layer E2 of electrode portion 5a is positioned on the first electrode layer E1 and on the side surface 3a. In electrode portion 5a, the second electrode layer E2 covers the entire first electrode layer E1 and a portion of the side surface 3a. The second electrode layer E2 of electrode portion 5a indirectly covers the first edge of the first electrode layer E1 such that the first electrode layer E1 is positioned between the second electrode layer E2 and the base body 3. In electrode portion 5a, the second electrode layer E2 is in direct contact with the first electrode layer E1. The portion of the electrode portion 5a covered by the second electrode layer E2 is located closer to the end face 3e. The side surface 3a is exposed from the second electrode layer E2 in the remaining portion excluding the portion covered by the second electrode layer E2. In electrode portion 5a, the second electrode layer E2 is in direct contact with the side surface 3a. In electrode portion 5a, the second electrode layer E2 directly covers the side surface 3a. The second electrode layer E2 of the electrode portion 5a is located on the side surface 3a and on the first edge.

[0033] The third electrode layer E3 of electrode portion 5a is positioned on the second electrode layer E2. In electrode portion 5a, the third electrode layer E3 covers the second electrode layer E2. In electrode portion 5a, the third electrode layer E3 is in contact with the second electrode layer E2. That is, in electrode portion 5a, the third electrode layer E3 is in direct contact with the second electrode layer E2. The fourth electrode layer E4 of electrode portion 5a is positioned on the third electrode layer E3. In electrode portion 5a, the fourth electrode layer E4 covers the third electrode layer E3. In electrode portion 5a, the fourth electrode layer E4 is in contact with the third electrode layer E3. That is, in electrode portion 5a, the fourth electrode layer E4 is in direct contact with the third electrode layer E3. In electrode portion 5a, the third electrode layer E3 and the fourth electrode layer E4 are not in contact with the side surface 3a. In electrode portion 5a, the third electrode layer E3 is located outside the second electrode layer E2 with a gap between it and the side surface 3a. In electrode portion 5a, the fourth electrode layer E4 is located outside the second electrode layer E2 with a gap between it and the side surface 3a. The fourth electrode layer E4 of electrode portion 5a is located outside the third electrode layer E3 of electrode portion 5a. The third electrode layer E3 and the fourth electrode layer E4 of electrode portion 5a are located on the side surface 3a.

[0034] For example, in a configuration where one of a pair of sides 3a is the mounting surface, the second electrode layer E2 of the electrode portion 5a located on the other pair of sides 3a may cover only a portion of the edge between each of the other pair of sides 3a and the end face 3e, and only a portion of each of the other pair of sides 3a. The portion of the edge between each of the other pair of sides 3a and the end face 3e is located, for example, closer to the side 3a that is the mounting surface. The portion of each of the other pair of sides 3a is located, for example, closer to the corners of the side 3a that is the mounting surface and the end face 3e. An electrode portion 5a located on another pair of sides 3a may have the following configurations: The second electrode layer E2 of the electrode portion 5a located on another pair of sides 3a indirectly covers a portion of the ridge between each of the other pair of sides 3a and the end face 3e, such that the first electrode layer E1 is located between the second electrode layer E2 and the first ridge. The second electrode layer E2 of the electrode portion 5a located on another pair of sides 3a directly covers a portion of each of the other pair of sides 3a. The second electrode layer E2 of the electrode portion 5a located on another pair of sides 3a directly covers a portion of the portion of the first electrode layer E1 located on the ridge between each of the other pair of sides 3a and the end face 3e. The electrode portion 5a located on another pair of sides 3a includes a region where the first electrode layer E1 is exposed from the second electrode layer E2 and a region where the first electrode layer E1 is covered by the second electrode layer E2.

[0035] The first electrode layer E1 of the electrode portion 5e is positioned on the end face 3e. The first electrode layer E1 of the electrode portion 5e covers the entire end face 3e. The first electrode layer E1 of the electrode portion 5e is in contact with the entire end face 3e. In other words, in the electrode portion 5e, the first electrode layer E1 is in direct contact with the end face 3e. The second electrode layer E2 of electrode portion 5e is positioned on the first electrode layer E1. In electrode portion 5e, the second electrode layer E2 covers the first electrode layer E1. In electrode portion 5e, the second electrode layer E2 is in direct contact with the first electrode layer E1. In electrode portion 5e, the second electrode layer E2 indirectly covers the end face 3e such that the first electrode layer E1 is located between the second electrode layer E2 and the end face 3e. The second electrode layer E2 of electrode portion 5e is located on the end face 3e.

[0036] The third electrode layer E3 of electrode portion 5e is positioned on the second electrode layer E2. In electrode portion 5e, the third electrode layer E3 covers the second electrode layer E2. In electrode portion 5e, the third electrode layer E3 is in contact with the second electrode layer E2. That is, in electrode portion 5e, the third electrode layer E3 is in direct contact with the second electrode layer E2. In electrode portion 5e, the third electrode layer E3 is not in direct contact with the first electrode layer E1. The fourth electrode layer E4 of electrode portion 5e is located on the third electrode layer E3. In electrode portion 5e, the fourth electrode layer E4 covers the third electrode layer E3. In electrode portion 5e, the fourth electrode layer E4 is in contact with the third electrode layer E3. That is, in electrode portion 5e, the fourth electrode layer E4 is in direct contact with the third electrode layer E3. In electrode portion 5e, the third electrode layer E3 and the fourth electrode layer E4 are located outside the second electrode layer E2. The fourth electrode layer E4 of electrode portion 5e is located outside the third electrode layer E3 of electrode portion 5e. The third electrode layer E3 and the fourth electrode layer E4 of electrode portion 5e are located on the end face 3e.

[0037] The second electrode layer E2 of the electrode portion 5e may cover only a portion of the end face 3e. This portion of the end face 3e is located, for example, closer to the side surface 3a. In this case, the electrode portion 5e may have the following configurations: The second electrode layer E2 of the electrode portion 5e indirectly covers the portion of the end face 3e such that the first electrode layer E1 is located between the second electrode layer E2 and the end face 3e. The second electrode layer E2 of the electrode portion 5e directly covers only a portion of the portion of the first electrode layer E1 located on the end face 3e. That is, the electrode portion 5e includes a region where the first electrode layer E1 is exposed from the second electrode layer E2 and a region where the first electrode layer E1 is covered by the second electrode layer E2.

[0038] The second electrode layer E2 of electrode portion 5e has a maximum thickness position E2 max Includes. In electrode portion 5e, maximum thickness position E2 max Therefore, the second electrode layer E2 has the greatest thickness. The thickness of the second electrode layer E2 in electrode portion 5e is at the position of maximum thickness E2 max It decreases towards the edge of electrode portion 5e. Therefore, the second electrode layer E2 of electrode portion 5e has the maximum thickness at position E2 max It includes a portion E2a containing a portion and a portion E2b having a thickness less than the thickness of the portion. Viewed from direction D1, portion E2a is located inside portion E2b. For example, if portion E2a contains the first portion, then portion E2b contains the second portion. Maximum thickness position E2 max The thickness of the second electrode layer E2 is 10 μm or more. Maximum thickness position: E2max The thickness of the second electrode layer E2 is, for example, 70 μm.

[0039] The first electrode layer E1 is formed by baking a conductive paste applied to the surface of the base body 3. The conductive paste is applied to one end face 3e and the first edge. The first electrode layer E1 is formed to cover one end face 3e and the first edge. The first electrode layer E1 is formed by sintering the metal component (metal powder) contained in the conductive paste. The first electrode layer E1 includes, for example, a sintered metal layer. The first electrode layer E1 includes a sintered metal layer formed on the base body 3. The first electrode layer E1 includes, for example, a sintered metal layer made of copper. The first electrode layer E1 may also include a sintered metal layer made of nickel. The first electrode layer E1 may also include a base metal. The conductive paste may include, for example, powder made of copper or nickel, a glass component, an organic binder, and an organic solvent. The first electrode layers E1 included in the electrode portions 5a and 5e are, for example, formed integrally with each other.

[0040] The second electrode layer E2 is formed by curing a conductive resin paste applied to the first electrode layer E1. The conductive resin paste is applied to the first electrode layer E1 and a portion of the side surface 3a. The second electrode layer E2 is formed across the first electrode layer E1 and the substrate 3. The conductive resin paste includes, for example, a plurality of conductive particles, a resin, and an organic solvent. The resin may include a thermosetting resin. The thermosetting resin may include a phenolic resin, an acrylic resin, a silicone resin, an epoxy resin, or a polyimide resin. The second electrode layer E2 is in contact with a portion of the second edge. The second electrode layer E2 included in the electrode portions 5a and 5e is formed integrally with each other, for example.

[0041] The second electrode layer E2 includes a portion E2c located on the central region Rc of the end face 3e and a portion E2o located on the outer peripheral region Ro of the end face 3e. The second electrode layer E2 of electrode portion 5e includes portion E2c and portion E2o. For example, if portion E2c includes the first portion, then portion E2o includes the second portion. The central region Rc and the outer peripheral region Ro of the end face 3e are defined, for example, as follows: As shown in Figure 4, the end face 3e is divided into 16 sections, and of these 16 sections, the 4 inner sections are defined as the central region Rc, and the 12 outer sections are defined as the outer peripheral region Ro. Viewed from direction D1, parts E2a and E2c may coincide, and parts E2b and E2o may coincide. Viewed from direction D1, part E2a may be larger than or smaller than part E2c. Viewed from direction D1, part E2b may be larger than or smaller than part E2o.

[0042] The third electrode layer E3 is formed on the second electrode layer E2 by a plating method. The third electrode layer E3 includes, for example, a nickel plating layer. The third electrode layer E3 may also contain nickel. The nickel plating layer tends to have better solder corrosion resistance than the conductive particles contained in the second electrode layer E2. The third electrode layer E3 covers the second electrode layer E2. The fourth electrode layer E4 is formed on the third electrode layer E3 by a plating method. The third electrode layer E3 includes an under-plating layer on which the fourth electrode layer E4 is formed. The fourth electrode layer E4 includes, for example, a solder plating layer. The solder plating layer may include a tin (Sn) plating layer. The fourth electrode layer E4 may contain tin. The fourth electrode layer E4 may be a tin-silver alloy (Sn-Ag) plating layer, a tin-bismuth alloy (Sn-Bi) plating layer, or a tin-copper alloy (Sn-Cu) plating layer. The fourth electrode layer E4 covers the third electrode layer E3.

[0043] The third electrode layer E3 and the fourth electrode layer E4 constitute the plating layer PL formed on the second electrode layer E2. That is, the external electrode 5 includes the plating layer PL, and the plating layer PL includes the third electrode layer E3 and the fourth electrode layer E4. The plating layer PL covers the second electrode layer E2. The third electrode layer E3, which is included in the electrode portions 5a and 5e, is formed integrally with each other, for example. The fourth electrode layer E4, which is included in the electrode portions 5a and 5e, is formed integrally with each other, for example. The plating layer PL may include another plating layer between the second electrode layer E2 and the third electrode layer E3. The plating layer PL may include another plating layer between the third electrode layer E3 and the fourth electrode layer E4.

[0044] As shown in Figures 5 and 6, each external electrode 5 has a hole 5h. The hole 5h is formed in the electrode portion 5e. The number of holes 5h is, for example, one. The hole 5h is formed from the surface of the plating layer PL and reaches the second electrode layer E2. The hole 5h is formed from the surface of the fourth electrode layer E4. The hole 5h penetrates the plating layer PL. The hole 5h reaches portion E2a of the second electrode layer E2. The hole 5h reaches portion E2c of the second electrode layer E2. The deepest point of hole 5h is located within the second electrode layer E2. In direction D1, the deepest point of hole 5h is located closer to the base material 3 than the interface between the second electrode layer E2 and the plating layer PL, and also closer to the plating layer PL than the interface between the second electrode layer E2 and the first electrode layer E1. Hole 5h reaches into the second electrode layer E2. Hole 5h reaches into portion E2a of the second electrode layer E2. Hole 5h reaches into portion E2c of the second electrode layer E2. Hole 5h does not penetrate the second electrode layer E2. The maximum depth of hole 5h in the second electrode layer E2 is less than the thickness of the second electrode layer E2 at the planned location where hole 5h is formed. The depth of hole 5h in the second electrode layer E2 is, for example, 1 μm or more.

[0045] The third electrode layer E3 is exposed to hole 5h. Within hole 5h, the third electrode layer E3 is exposed from the fourth electrode layer E4 and is not covered by the fourth electrode layer E4. The second electrode layer E2 is exposed to hole 5h. Within hole 5h, the second electrode layer E2 is exposed from the fourth electrode layer E4 and is not covered by the fourth electrode layer E4. The second electrode layer E2 is spaced apart from the fourth electrode layer E4 on the inner wall surface defining hole 5h. Hole 5h does not reach the first electrode layer E1. Therefore, the first electrode layer E1 is not exposed to hole 5h.

[0046] The inner diameter of the hole 5h in the fourth electrode layer E4 may be larger than the inner diameter of the hole 5h in the third electrode layer E3. In configurations where the inner diameter of the hole 5h in the fourth electrode layer E4 is larger than that of the hole 5h in the third electrode layer E3, the hole 5h decreases in diameter from, for example, the opening on the surface of the plating layer PL to its deepest point. The inner diameter of the hole 5h in the fourth electrode layer E4 is, for example, 1 to 70 μm. The inner diameter of the hole 5h in the third electrode layer E3 is, for example, 1 to 30 μm. The ratio of the inner diameter of the hole 5h in the third electrode layer E3 to the inner diameter of the hole 5h in the fourth electrode layer E4 is, for example, 1 / 4 to 2 / 3. The inner diameter of the hole 5h in the fourth electrode layer E4 is defined, for example, by the inner diameter of the opening of the hole 5h on the surface of the fourth electrode layer E4. The inner diameter of the hole 5h in the third electrode layer E3 is defined, for example, by the inner diameter of the opening of the hole 5h on the surface of the third electrode layer E3, i.e., at the interface between the fourth electrode layer E4 and the third electrode layer E3. The inner diameter of hole 5h in the second electrode layer E2 is smaller than, for example, the inner diameter of hole 5h in the third electrode layer E3. The inner diameter of hole 5h in the second electrode layer E2 is, for example, 1 to 30 μm. The inner diameter of the hole 5h in the second electrode layer E2 is defined, for example, by the inner diameter of the opening of the hole 5h on the surface of the second electrode layer E2, i.e., at the interface between the third electrode layer E3 and the second electrode layer E2.

[0047] The opening of hole 5h in the fourth electrode layer E4 is, for example, approximately circular. The opening of hole 5h in the third electrode layer E3 is, for example, approximately circular. The opening of hole 5h in the second electrode layer E2 is, for example, approximately circular. Each opening of hole 5h may have a shape other than circular. Each opening of hole 5h may have a roughly polygonal shape. In configurations where the opening of hole 5h is not circular, the inner diameter of hole 5h is defined, for example, as follows: After the area of ​​the opening of hole 5h is obtained, the equivalent circular diameter of this area is calculated. The calculated equivalent circular diameter defines the inner diameter of hole 5h. In a configuration where the plating layer PL includes another plating layer between the third electrode layer E3 and the fourth electrode layer E4, the inner diameter of the hole 5h in the other plating layer is, for example, larger than the inner diameter of the hole 5h in the third electrode layer E3 and smaller than the inner diameter of the hole 5h in the fourth electrode layer E4.

[0048] As shown in Figures 7 and 8, each external electrode 5 may have multiple holes 5h. Figure 7 is a diagram showing the planar configuration of the external electrode. Figure 8 is a diagram showing the cross-sectional configuration of the external electrode. In Figure 8, the hatching indicating the cross-section is omitted. In a configuration where the external electrode 5 has a plurality of holes 5h, the plurality of holes 5h may be formed in the electrode portion 5e. Each of the plurality of holes 5h is formed from the surface of the plating layer PL and reaches the second electrode layer E2. Each of the plurality of holes 5h may reach portion E2a. Each of the plurality of holes 5h may reach portion E2c. The shapes or depths of the plurality of holes 5h may differ from each other. Although not shown in the figures, the plurality of holes 5h may include holes 5h that reach portion E2b in addition to holes 5h that reach portion E2a, and the plurality of holes 5h may include holes 5h that reach portion E2o in addition to holes 5h that reach portion E2c.

[0049] The manufacturing process of the multilayer capacitor C1 will be explained with reference to Figure 9. Figure 9 is a schematic diagram showing the manufacturing process of the multilayer capacitor according to this embodiment. The manufacturing process of the multilayer capacitor C1 includes preparing a base body 3 on which external electrodes 5 are formed, and forming holes 5h in the external electrodes 5. The external electrodes 5 formed on the base body 3 include, as described above, a first electrode layer E1, a second electrode layer E2, and a plating layer PL (third electrode layer E3 and fourth electrode layer E4). The manufacturing process of the base body 3 is known in the art, and a detailed explanation is omitted. Forming the hole 5h includes forming a hole 5h that extends from the surface of the plating layer PL to the second electrode layer E2. The hole 5h is formed from the outside of the external electrode 5. Forming the hole 5h may also include forming a hole 5h that extends from the surface of the plating layer PL to the inside of the second electrode layer E2.

[0050] As shown in Figure 9, the hole 5h is formed, for example, by laser irradiation. That is, forming the hole 5h involves irradiating the surface of the external electrode 5, i.e., the surface of the plating layer PL, with a laser. The laser irradiation is performed by a laser irradiation device LD. The laser irradiation device LD includes a laser light source (not shown) and irradiates the surface of the plating layer PL with laser light LL from the laser light source. The depth and inner diameter of the hole 5h are adjusted, for example, by adjusting the laser irradiation conditions. The laser irradiation conditions include, for example, the pulse energy of the laser light LL or the irradiation time of the laser light LL. The hole 5h may also be formed by micro-hole machining by cutting.

[0051] In the multilayer capacitor C1, the holes 5h in the external electrode 5 are formed from the surface of the plating layer PL and reach the second electrode layer E2. When the multilayer capacitor C1 is heated, even if the moisture absorbed by the resin contained in the second electrode layer E2 gasifies, the gas generated from the moisture moves outside the external electrode 5 through the holes 5h. In other words, the holes 5h form a gas movement path. Therefore, stress is less likely to act on the second electrode layer E2. As a result, the multilayer capacitor C1 suppresses the occurrence of cracks in the second electrode layer E2.

[0052] In the multilayer capacitor C1, the plating layer PL may include a third electrode layer E3 and a fourth electrode layer E4. The fourth electrode layer E4 may include a solder plating layer. The inner diameter of the hole 5h in the fourth electrode layer E4 may be larger than the inner diameter of the hole 5h in the third electrode layer E3. When a multilayer capacitor C1 is soldered into an electronic device, the fourth electrode layer E4 becomes wet with molten solder. In this case, the molten solder may clog the hole 5h. In a configuration where the inner diameter of the hole 5h in the fourth electrode layer E4 is larger than the inner diameter of the hole 5h in the third electrode layer E3, even if the fourth electrode layer E4 is wetted with molten solder, the molten solder is less likely to block the hole 5h. Therefore, even when the multilayer capacitor C1 is soldered to electronic equipment, a multilayer capacitor C1 having this configuration reliably suppresses the occurrence of cracks in the second electrode layer E2.

[0053] In the multilayer capacitor C1, the second electrode layer E2 may include a portion E2a that includes the position of the maximum thickness in the second electrode layer E2, and a portion E2b that has a thickness smaller than the thickness of portion E2a. The hole 5h may reach portion E2a. Part E2a has a greater thickness than part E2b. Therefore, part E2a may absorb more moisture than part E2b. In a configuration where the hole 5h reaches portion E2a, the hole 5h forms a gas migration path from portion E2a. Gas generated from moisture absorbed in portion E2a reliably moves outside the external electrode 5 through the hole. Therefore, stress is less likely to act on portion E2a of the second electrode layer E2. A multilayer capacitor C1 having this configuration reliably suppresses the occurrence of cracks in the second electrode layer E2.

[0054] In the multilayer capacitor C1, the element 3 may include an end face 3e, and the external electrode 5 may be located on the end face 3e. The second electrode layer E2 may include a portion E2c located on the central region Rc of the end face 3e and a portion E2o located on the outer peripheral region Ro of the end face 3e. The hole 5h may reach portion E2c. The second electrode layer E2 is formed, for example, by curing a conductive resin paste. The conductive resin paste contains, for example, a curable resin and an organic solvent. The organic solvent vaporizes. The vaporization of the organic solvent generates gas within the conductive resin paste. The gas generated by the vaporization of the organic solvent travels directly from any point in the conductive resin paste where the organic solvent is present to the surface of the conductive resin paste and escapes from the conductive resin paste. As a result of the vaporization of the organic solvent, voids are formed in each of the aforementioned points within the conductive resin paste, serving as pathways for the gas. In other words, the second electrode layer E2 tends to contain multiple voids. The inventors have newly discovered that when the second electrode layer E2 is formed from a conductive resin paste, portion E2c tends to contain more voids than portion E2o. In a configuration where the hole 5h extends to portion E2c, the hole 5h is easily accessible to the voids that are abundant in portion E2c. Gas generated from moisture absorbed in portion E2c travels from the voids to the hole. Therefore, gas generated from moisture moves more easily outside the external electrode 5. Stress is less likely to act on the second electrode layer E2. A multilayer capacitor C1 having this configuration further suppresses the occurrence of cracks in the second electrode layer E2.

[0055] In the multilayer capacitor C1, the hole 5h may extend into the second electrode layer E2. In a configuration where the hole 5h reaches into the second electrode layer E2, gas generated from moisture easily reaches the hole 5h. Therefore, stress is less likely to act on the second electrode layer E2. As a result, the multilayer capacitor C1 having this configuration further suppresses the occurrence of cracks in the second electrode layer E2.

[0056] During the manufacturing process of the multilayer capacitor C1, holes 5h are formed in the external electrodes 5 on the prepared substrate 3, extending from the surface of the plating layer PL to the second electrode layer E2. As described above, these holes 5h form gas transfer paths generated from moisture absorbed by the resin contained in the second electrode layer E2. Therefore, stress is less likely to act on the second electrode layer E2 in the multilayer capacitor C1. As a result, the manufacturing process described above yields a multilayer capacitor C1 that suppresses the occurrence of cracks in the second electrode layer E2.

[0057] In the manufacturing process described above, forming the hole 5h may include forming the hole 5h so that it reaches into the second electrode layer E2. If forming the hole 5h includes forming the hole 5h so that it reaches into the second electrode layer E2, then in the resulting multilayer capacitor C1, as described above, gas generated from moisture is more likely to reach the hole 5h. In this case, in the resulting multilayer capacitor C1, stress is less likely to act on the second electrode layer E2, and the occurrence of cracks in the second electrode layer E2 is further suppressed.

[0058] In the manufacturing process described above, forming the hole 5h may include irradiating the surface of the plating layer PL with a laser. If forming the hole 5h involves irradiating the surface of the plating layer PL with a laser, then the hole 5h is formed by the laser irradiation. Therefore, a hole reaching from the surface of the plating layer PL to the second electrode layer E2 is formed easily and reliably.

[0059] Next, the configuration of an electronic component device (ECD) according to another embodiment will be described with reference to Figures 10 and 11. Figure 10 is a diagram showing the cross-sectional configuration of an electronic component device according to another embodiment. Figure 11 is a diagram showing the planar configuration of the external electrode and solder fillet. The electronic component device ECD comprises a multilayer capacitor C1 and an electronic device ED. The electronic device ED is, for example, a circuit board or an electronic component. The multilayer capacitor C1 is solder-mounted on the electronic device ED. The electronic device ED includes a main surface EDa and a pair of pad electrodes PE. Each pad electrode PE is positioned on the main surface EDa. The pair of pad electrodes PE are spaced apart from each other. The multilayer capacitor C1 is positioned on the electronic device ED such that one side surface 3a faces the main surface EDa.

[0060] When a multilayer capacitor C1 is soldered, molten solder wets each external electrode 5 (fourth electrode layer E4). As the wetted solder solidifies, a solder fillet SF is formed on each external electrode 5. The corresponding external electrodes 5 and pad electrodes PE are connected via the solder fillet SF. Hole 5h is exposed from the solder fillet SF. In other words, hole 5h is exposed from the solidified solder. In the multilayer capacitor C1, the occurrence of cracks in the second electrode layer E2 is suppressed.

[0061] While embodiments of the present invention have been described above, the present invention is not necessarily limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0062] The inner diameter of the hole 5h in the fourth electrode layer E4 does not have to be larger than the inner diameter of the hole 5h in the third electrode layer E3. As described above, a configuration in which the inner diameter of the hole 5h in the fourth electrode layer E4 is larger than the inner diameter of the hole 5h in the third electrode layer E3 reliably suppresses the occurrence of cracks in the second electrode layer E2.

[0063] In this embodiment and its modified examples, a multilayer capacitor was used as an example of an electronic component, but the applicable electronic components are not limited to multilayer capacitors. Applicable electronic components include, for example, multilayer electronic components such as multilayer inductors, multilayer varistors, multilayer piezoelectric actuators, multilayer thermistors, multilayer solid-state battery components, or multilayer composite components, or electronic components other than multilayer electronic components.

[0064] As can be seen from the descriptions of the embodiments described above, this specification includes disclosures of the following embodiments. (Note 1) The base body and, The body is arranged and comprises an external electrode including a conductive resin layer and a plating layer formed on the conductive resin layer, The external electrode is an electronic component having a hole formed from the surface of the plating layer and reaching the conductive resin layer. (Note 2) The aforementioned plating layer includes an undercoat plating layer and a solder plating layer located on the undercoat plating layer. The electronic component as described in Appendix 1, wherein the inner diameter of the hole in the solder plating layer is larger than the inner diameter of the hole in the undercoat plating layer. (Note 3) The conductive resin layer includes a first portion that includes the position of maximum thickness in the conductive resin layer, and a second portion that has a thickness less than the thickness of the first portion. The hole extends to the first portion, and is an electronic component as described in Appendix 1 or 2. (Note 4) The aforementioned body includes an end face, The external electrode is located on the substrate, The conductive resin layer includes a first portion located on the central region of the end face and a second portion located on the outer peripheral region of the end face. The hole extends to the first portion, and is an electronic component as described in Appendix 1 or 2. (Note 5) The aforementioned hole extends into the conductive resin layer, and is an electronic component as described in any one of the appendices 1 to 4. (Note 6) The electronic component listed in any one of the appendices 1 to 5, The electronic device comprises the aforementioned electronic components being soldered on, The aforementioned hole is exposed from the solder in the electronic component device. (Note 7) A substrate is prepared on which an external electrode is formed, which includes a conductive resin layer and a plating layer formed on the conductive resin layer. A method for manufacturing an electronic component, comprising forming a hole in the external electrode that extends from the surface of the plating layer to the conductive resin layer. (Note 8) The method for manufacturing an electronic component according to Appendix 7, wherein forming the hole includes forming the hole so that it reaches into the conductive resin layer. (Note 9) The method for manufacturing an electronic component according to Appendix 7 or 8, wherein forming the hole includes irradiating the surface of the plating layer with a laser. [Explanation of Symbols]

[0065] 3...element body, 3e...end surface, 5...external electrode, 5h...hole, C1...multilayer capacitor, E1...first electrode layer, E2...second electrode layer, E2 max ...Maximum thickness position, E2a, E2b, E2c, E2o...Part included in the second electrode layer, E3...Third electrode layer, E4...Fourth electrode layer, ECD...Electronic component device, ED...Electronic device, LD...Laser irradiation device, LL...Laser light, PL...Plating layer, Rc...Central region of the end face, Ro...Peripheral region of the end face, SF...Solder fillet.

Claims

1. The base body and, The body is arranged and comprises an external electrode including a conductive resin layer and a plating layer formed on the conductive resin layer, The external electrode is an electronic component having a hole formed from the surface of the plating layer and reaching the conductive resin layer.

2. The aforementioned plating layer includes an undercoat plating layer and a solder plating layer disposed on the undercoat plating layer. The electronic component according to claim 1, wherein the inner diameter of the hole in the solder plating layer is larger than the inner diameter of the hole in the undercoat plating layer.

3. The conductive resin layer includes a first portion that includes the position of maximum thickness in the conductive resin layer, and a second portion that has a thickness less than the thickness of the first portion. The electronic component according to claim 1, wherein the hole reaches the first portion.

4. The aforementioned body includes an end face, The external electrode is located on the end face, The conductive resin layer includes a first portion located on the central region of the end face and a second portion located on the outer peripheral region of the end face. The electronic component according to claim 1, wherein the hole reaches the first portion.

5. The electronic component according to claim 1, wherein the hole reaches into the conductive resin layer.

6. An electronic component according to any one of claims 1 to 5, The electronic device comprises the aforementioned electronic components being soldered on, The aforementioned hole is exposed from the solder in the electronic component device.

7. A substrate is prepared on which an external electrode is formed, which includes a conductive resin layer and a plating layer formed on the conductive resin layer. A method for manufacturing an electronic component, comprising forming a hole in the external electrode that extends from the surface of the plating layer to the conductive resin layer.

8. The method for manufacturing an electronic component according to claim 7, wherein forming the hole includes forming the hole so that it reaches into the conductive resin layer.

9. The method for manufacturing an electronic component according to claim 7 or 8, wherein forming the hole includes irradiating the surface of the plating layer with a laser.

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