Patent Application
20250069812
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2023-135287, filed on Aug. 23, 2023, the entire contents of which are incorporated herein by reference.
The present disclosure relates to an electronic component.
Known electronic components include an element body and an external electrode on the element body (see, for example, Japanese Unexamined Patent Publication No. H5-144665). The external electrode includes, for example, a conductive resin layer and a metal plating layer outside the conductive resin layer.
The conductive resin layer includes, for example, a plurality of silver particles and a resin. In a configuration in which the external electrode includes the conductive resin layer, silver migration may occur in the external electrode. The silver migration is considered to occur due to the following events, for example.
Electric field or heat acts on the conductive resin layer, and the silver particle is ionized. The silver particle included in the conductive resin layer may be ionized under influence of oxygen. Generated silver ion is attracted by electric field between the external electrodes and migrates from the conductive resin layer. The electric field acting on the silver particle includes, for example, electric field between the external electrodes or electric field between the external electrode and an internal conductor in the element body. The silver ion migrating from the conductive resin layer react with, for example, an electron supplied from the internal conductor or the external electrode, and is deposited as silver on a surface of the element body.
One aspect of the present disclosure provides an electronic component preventing progress of silver migration.
An electronic component according to one aspect of the present disclosure includes an element body and an external electrode on the element body. The external electrode includes a conductive resin layer including a plurality of silver particles and a metal plating layer disposed outside the conductive resin layer with a gap between the metal plating layer and the element body. The electronic component according to the one aspect described above includes an oxide of a metal component included in the metal plating layer. The oxide is in contact with the metal plating layer and the element body and is disposed in the gap between the metal plating layer and the element body.
In the one aspect described above, the oxide is in contact with the metal plating layer and the element body and is disposed in the gap between the metal plating layer and the element body. Therefore, even when silver migration occurs in the conductive resin layer, progress of silver migration is prevented. The one aspect described above prevents the progress of silver migration on the element body.
The oxide in contact with the metal plating layer and the element body and disposed in the gap between the metal plating layer and the element body includes the oxide of the metal component included in the metal plating layer. Therefore, in the one aspect described above, the oxide is reliably disposed in the gap between the metal plating layer and the element body.
In the one aspect described above, the metal plating layer may include a copper plating layer. The oxide may include an oxide of copper included in the copper plating layer.
In a configuration in which the oxide includes an oxide of copper included in the copper plating layer, the oxide may be formed from heat treating the copper plating layer. Therefore, the oxide may be easily disposed.
In the one aspect described above, the metal plating layer may include an other metal plating layer different from the copper plating layer, the other metal plating layer being disposed outside the copper plating layer with a gap between the other metal plating layer and the element body.
In a configuration in which the metal plating layer includes the other metal plating layer, the other metal plating layer has the gap between the other metal plating layer and the element body. Heat tends to act on the copper plating layer through the gap between the other metal plating layer and the element body when heat-treating the copper plating layer, for example. Therefore, even in the configuration in which the metal plating layer includes the other metal plating layer, the oxide may be easily and reliably disposed.
In the one aspect described above, the other metal plating layer may include a nickel plating layer.
A configuration in which the other metal plating layer includes the nickel plating layer prevents solder leaching when solder-mounting.
In the one aspect described above, the other metal plating layer may include a solder plating layer outside the nickel plating layer.
A configuration in which the other metal plating layer includes the solder plating layer improves solder-mountability.
In the one aspect described above, the solder plating layer may have a gap between the solder plating layer and the element body.
In a configuration in which the solder plating layer has a gap between the solder plating layer and the element body, heat tends to act on the copper plating layer through the gap between the solder plating layer and the element body when heat-treating the copper plating layer, for example. Therefore, even in a configuration in which the metal plating layer includes the solder plating layer, the oxide may be easily and reliably disposed.
In the one aspect described above, the oxide may extend along an edge of the conductive resin layer.
A configuration in which the oxide extends along the edge of the conductive resin layer reliably prevents the progress of silver migration.
In the following description, with reference to the drawings, the same reference numbers are assigned to the same components or to similar components having the same function, and overlapping description is omitted.
A configuration of a multilayer capacitor C1 according to the example will be described with reference to
An electronic component includes, for example, the multilayer capacitor C1.
As illustrated in
The element body 3 includes a pair of side surfaces 3a opposing each other, a pair of side surfaces 3c opposing each other, and a pair of end surfaces 3e opposing each other. The pair of side surfaces 3a, the pair of side surfaces 3c, and the pair of end surfaces 3e each have a substantially rectangular shape. A direction in which the pair of side surfaces 3a oppose each other includes a direction D2. A direction in which the pain of side surfaces 3c oppose each other includes a direction D3. A direction in which the pair of end surfaces 3e oppose each other includes a direction D1.
The multilayer capacitor C1 is solder-mounted on an electronic device, for example. The electronic device includes, for example, a circuit board or an electronic component. In the multilayer capacitor C1, for example, one of the four side surfaces 3a and 3c opposes the electronic device. The one of the four side surfaces 3a and 3c is arranged to constitute a mounting surface. The one of the four side surfaces 3a and 3c includes the mounting surface. For example, the side surface 3a includes the mounting surface.
The direction D2 includes a direction orthogonal to the side surfaces 3a, and is orthogonal to the direction D3. The direction D1 includes a direction parallel to the side surfaces 3a and the side surfaces 3c, and is orthogonal to the direction D2 and the direction D3. The direction D3 includes a direction orthogonal to the side surfaces 3c, and the direction D1 includes a direction orthogonal to the end surfaces 3e. For example, a length of the element body 3 in the direction D1 is larger than a length of the element body 3 in the direction D2 and larger than a length of the element body 3 in the direction D3. The direction D1 includes a longitudinal direction of the element body 3. The length of the element body 3 in the direction D2 and the length of the element body 3 in the direction D3 may be equal to each other. The length of the element body 3 in the direction D2 and the length of the element body 3 in the direction D3 may be different from each other.
The length of the element body 3 in the direction D2 defines, for example, a height of the element body 3. The length of the element body 3 in the direction D3 defines, for example, a width of the element body 3. The length of the element body 3 in the direction D1 defines, for example, a longitudinal length of the element body 3. For example, the height of the element body 3 is 0.1 to 3.2 mm, the width of the element body 3 is 0.1 to 6.3 mm, and the longitudinal length of the element body 3 is 0.2 to 7.5 mm. For example, the height of the element body 3 is 2.5 mm, the width of the element body 3 is 2.5 mm, and the longitudinal length of the element body 3 is 3.2 mm.
The pair of side surfaces 3a extend in the direction D3 to couple the pair of side surfaces 3c to each other. The pair of side surfaces 3a also extend in the direction D1. The pair of side surfaces 3c extend in the direction D2 to couple the pair of side surfaces 3a to each other. The pair of side surfaces 3c also extend in the direction D1. The pair of end surfaces 3e extend in the direction D2 to couple the pair of side surfaces 3a to each other. The pair of end surfaces 3e also extend in the direction D3 to couple the pair of side surfaces 3c to each other.
The element body 3 includes a ridge portion between the end surface 3e and the side surface 3a, a ridge portion between the end surface 3e and the side surfaces 3c, and a ridge portion between the side surface 3a and the side surface 3c. For example, the ridge portions are rounded to be curved. For example, the element body 3 is subjected to what is called a round chamfering process. The end surface 3e and the side surface 3a are indirectly adjacent to each other with the ridge portion interposed between the end surface 3e and the side surface 3a. The end surface 3e and the side surface 3c are indirectly adjacent to each other with the ridge portion interposed between the end surface 3e and the side surface 3c. The side surface 3a and the side surface 3c are indirectly adjacent to each other with the ridge portion interposed between the side surface 3a and the side surface 3c.
The element body 3 is configured through laminating a plurality of dielectric layers in the direction D2. The element body 3 includes a plurality of laminated dielectric layers. In the element body 3, a lamination direction of the plurality of dielectric layers coincides with the direction D2. Each dielectric layer includes, for example, a sintered body of a ceramic green sheet containing a dielectric material. Examples of the dielectric material include dielectric ceramics. Examples of the dielectric ceramics include BaTiO3-based, Ba(Ti, Zr)O3-based, or (Ba, Ca)TiO3-based dielectric ceramics. In the actual element body 3, each of the dielectric layers is integrated to such an extent that a boundary between the dielectric layers cannot be visually recognized.
As illustrated in
The plurality of internal electrodes 7 are disposed in different positions (layers) in the direction D2. The plurality of internal electrodes 7 are alternately disposed in the element body 3 to oppose each other in the direction D2 with an interval therebetween. The internal electrodes 7 adjacent to each other in the direction D2 have different polarities from each other. One end of the internal electrode 7 is exposed to a corresponding end surface 3e of the pair of end surfaces 3e. The internal electrode 7 includes one end exposed to the corresponding end surface 3e. The plurality of internal electrodes 7 include an internal electrode 7 exposed to one end surface 3e of the pair of end surfaces 3e and an internal electrode 7 exposed to the other end surface 3e of the pair of end surfaces 3e. The internal electrodes 7 exposed to the one end surface 3e and the internal electrodes 7 exposed to the other end surface 3e are alternately disposed in the direction D2. The plurality of internal electrodes 7 are disposed in the element body 3 to be distributed in the direction D2. Each of the plurality of internal electrodes 7 is located in a plane substantially parallel to the side surfaces 3a. A direction in which the internal electrodes 7 oppose each other, that is, the direction D2 is orthogonal to a direction parallel to the side surfaces 3a. The direction in which the internal electrodes 7 oppose each other is orthogonal to the directions D3 and D1.
In a configuration in which the lamination direction of the plurality of dielectric layers includes the direction D3, the plurality of internal electrodes 7 are disposed in different positions (layers) in the direction D3. In a configuration in which the lamination direction of the plurality of dielectric layers includes the direction D3, the internal electrodes 7 exposed to the one end surface 3e and the internal electrodes 7 exposed to the other end surface 3e are alternately disposed in the direction D3. Each of the plurality of internal electrodes 7 is located in a plane substantially parallel to the side surfaces 3c. The internal electrodes 7 oppose each other in the direction D3.
As illustrated in
Each external electrode 5 is formed on five surfaces of the pair of side surfaces 3a, the pair of side surfaces 3c, and the end surface 3e as well as the above-described ridge portions. The electrode portions 5a, 5c, and 5e adjacent to each other are coupled and are electrically connected to each other. The electrode portion 5e covers the entire one end of a corresponding internal electrodes 7 of the plurality of internal electrodes 7. The 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.
As illustrated in
The first electrode layer E1 of the electrode portion 5a is disposed on the ridge portion between the side surface 3a and the end surface 3e, and not disposed on the side surface 3a. The first electrode layer E1 of the electrode portion 5a covers the entire ridge portion between the side surface 3a and the end surface 3e. The first electrode layer E1 of the electrode portion 5a does not cover the side surface 3a. The first electrode layer E1 of the electrode portion 5a is in contact with the ridge portion between the side surface 3a and the end surface 3e. The side surface 3a is exposed from the first electrode layer E1. The first electrode layer E1 of the electrode portion 5a may be disposed on the side surface 3a. The first electrode layer E1 of the electrode portion 5a may cover a partial region of the side surface 3a and the entire ridge portion between the side surface 3a and the end surface 3e. The first electrode layer E1 of the electrode portion 5a may be in contact with the partial region of the side surface 3a. The partial region covered with the first electrode layer E1 of the electrode portion 5a may be positioned closer to the end surface 3e.
The second electrode layer E2 of the electrode portion 5a is disposed on both the first electrode layer E1 and the side surface 3a. In the electrode portion 5a, the second electrode layer E2 covers the entire first electrode layer E1 and a partial region of the side surface 3a. The second electrode layer E2 of the electrode portion 5a indirectly covers the ridge portion between the side surface 3a and the end surface 3e such that the first electrode layer E1 is positioned between the second electrode layer E2 and the element body 3. In the electrode portion 5a, the second electrode layer E2 is in direct contact with the first electrode layer E1. The partial region covered with the second electrode layer E2 of the electrode portion 5a is positioned closer to the end surface 3e. The side surface 3a is exposed from the second electrode layer E2 at the remaining region excluding the partial region covered with the second electrode layer E2. In the electrode portion 5a, the second electrode layer E2 is in direct contact with the side surface 3a. In the 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 positioned on both the side surface 3a and the ridge portion between the side surface 3a and the end surface 3e.
The third electrode layer E3 of the electrode portion 5a is disposed on the second electrode layer E2. In the electrode portion 5a, the third electrode layer E3 covers the second electrode layer E2. In the electrode portion 5a, the third electrode layer E3 is in contact with the second electrode layer E2. In the electrode portion 5a, the third electrode layer E3 is in direct contact with the second electrode layer E2.
The fourth electrode layer E4 of the electrode portion 5a is disposed on the third electrode layer E3. In the electrode portion 5a, the fourth electrode layer E4 covers the third electrode layer E3. In the electrode portion 5a, the fourth electrode layer E4 is in contact with the third electrode layer E3. In the electrode portion 5a, the fourth electrode layer E4 is in direct contact with the third electrode layer E3.
The fifth electrode layer E5 of the electrode portion 5a is disposed on the fourth electrode layer E4. In the electrode portion 5a, the fifth electrode layer E5 covers the fourth electrode layer E4. In the electrode portion 5a, the fifth electrode layer E5 is in contact with the fourth electrode layer E4. In the electrode portion 5a, the fifth electrode layer E5 is in direct contact with the fourth electrode layer E4.
In the electrode portion 5a, the third electrode layer E3, the fourth electrode layer E4, and the fifth electrode layer E5 are not in contact with the side surface 3a. In the electrode portion 5a, the third electrode layer E3, fourth electrode layer E4, and fifth electrode layer E5 are disposed outside the second electrode layer E2 with a gap between the third electrode layer E3, fourth electrode layer E4, and fifth electrode layer E5 and the side surface 3a. That is, the third electrode layer E3, the fourth electrode layer E4, and the fifth electrode layer E5 are separated from the side surface 3a (element body 3). The fourth electrode layer E4 of the electrode portion 5a is disposed outside the third electrode layer E3 of the electrode portion 5a. The fifth electrode layer E5 of the electrode portion 5a is disposed outside the fourth electrode layer E4 of the electrode portion 5a. The third electrode layer E3, fourth electrode layer E4, and fifth electrode layer E5 of the electrode portion 5a are positioned on the side surface 3a.
The first electrode layer E1 of the electrode portion 5c is disposed on the ridge portion between the side surface 3c and the end surface 3e, and not disposed on the side surface 3c. The first electrode layer E1 of the electrode portion 5c covers the entire ridge portion between the side surface 3c and the end surface 3e. The first electrode layer E1 of the electrode portion 5c does not cover the side surface 3c. The first electrode layer E1 of the electrode portion 5c is in contact with the ridge portion between the side surface 3c and the end surface 3e. The side surface 3c is exposed from the first electrode layer E1. The first electrode layer E1 of the electrode portion 5c may be disposed on the side surface 3c. The first electrode layer E1 of the electrode portion 5c may cover a partial region of the side surface 3c and the entire ridge portion between the side surface 3c and the end surface 3e. The first electrode layer E1 of the electrode portion 5c may be in contact with the partial region of the side surface 3c. The partial region covered with the first electrode layer E1 of the electrode portion 5c may be positioned closer to the end surface 3e.
The second electrode layer E2 of the electrode portion 5c is disposed on both the first electrode layer E1 and the side surface 3c. In the electrode portion 5c, the second electrode layer E2 covers the entire first electrode layer E1 and a partial region of the side surface 3c. The second electrode layer E2 of the electrode portion 5c indirectly covers the ridge portion between the side surface 3c and the end surface 3e such that the first electrode layer E1 is positioned between the second electrode layer E2 and the element body 3. In the electrode portion 5c, the second electrode layer E2 is in direct contact with the first electrode layer E1. The partial region covered with the second electrode layer E2 of the electrode portion 5c is positioned closer to the end surface 3e. The side surface 3c is exposed from the second electrode layer E2 at the remaining region excluding the partial region covered with the second electrode layer E2. In the electrode portion 5c, the second electrode layer E2 is in direct contact with the side surface 3c. In the electrode portion 5c, the second electrode layer E2 directly covers the side surface 3c. The second electrode layer E2 of the electrode portion 5c is positioned on both the side surface 3c and the ridge portion between the side surface 3c and the end surface 3e.
The third electrode layer E3 of the electrode portion 5c is disposed on the second electrode layer E2. In the electrode portion 5c, the third electrode layer E3 covers the second electrode layer E2. In the electrode portion 5c, the third electrode layer E3 is in contact with the second electrode layer E2. In the electrode portion 5c, the third electrode layer E3 is in direct contact with the second electrode layer E2.
The fourth electrode layer E4 of the electrode portion 5c is disposed on the third electrode layer E3. In the electrode portion 5c, the fourth electrode layer E4 covers the third electrode layer E3. In the electrode portion 5c, the fourth electrode layer E4 is in contact with the third electrode layer E3. In the electrode portion 5c, the fourth electrode layer E4 is in direct contact with the third electrode layer E3.
The fifth electrode layer E5 of the electrode portion 5c is disposed on the fourth electrode layer E4. In the electrode portion 5c, the fifth electrode layer E5 covers the fourth electrode layer E4. In the electrode portion 5c, the fifth electrode layer E5 is in contact with the fourth electrode layer E4. In the electrode portion 5c, the fifth electrode layer E5 is in direct contact with the fourth electrode layer E4.
In the electrode portion 5c, the third electrode layer E3, the fourth electrode layer E4, and the fifth electrode layer E5 are not in contact with the side surface 3c. In the electrode portion 5c, the third electrode layer E3, fourth electrode layer E4, and fifth electrode layer E5 are disposed outside the second electrode layer E2 with a gap between the third electrode layer E3, fourth electrode layer E4, and fifth electrode layer E5 and the side surface 3c. That is, the third electrode layer E3, the fourth electrode layer E4, and the fifth electrode layer E5 are separated from the side surface 3c (element body 3). The fourth electrode layer E4 of the electrode portion 5c is disposed outside the third electrode layer E3 of the electrode portion 5c. The fifth electrode layer E5 of the electrode portion 5c is disposed outside the fourth electrode layer E4 of the electrode portion 5c. The third electrode layer E3, fourth electrode layer E4, and fifth electrode layer E5 of the electrode portion 5c are positioned on the side surface 3c.
The second electrode layer E2 of the electrode portion 5c may cover only a partial region of the ridge portion between the side surface 3c and the end surface 3e and only a partial region of the side surface 3c. The above-described partial region of the ridge portion between the side surface 3c and the end surface 3e is positioned closer to the side surface 3a, for example. The above-described partial region of the side surface 3c is positioned at a corner, of the side surface 3c, closer to the side surface 3a and the end surface 3e, for example. The electrode portion 5c may have the following configuration. The second electrode layer E2 of the electrode portion 5c indirectly covers the above-described partial region of the ridge portion between the side surface 3c and the end surface 3e such that the first electrode layer E1 is positioned between the second electrode layer E2 and the ridge portion between the side surface 3c and the end surface 3e. The second electrode layer E2 of the electrode portion 5c directly covers the above-described partial region of the side surface 3c. The second electrode layer E2 of the electrode portion 5c directly covers a partial region of a portion, of the first electrode layer E1, positioned on the ridge portion between the side surface 3c and the end surface 3e. The electrode portion 5c includes a region in which the first electrode layer E1 is exposed from the second electrode layer E2 and a region in which the first electrode layer E1 is covered with the second electrode layer E2.
The first electrode layer E1 of the electrode portion 5e is disposed on the end surface 3e. The first electrode layer E1 of the electrode portion 5e covers the entire end surface 3e. The first electrode layer E1 of the electrode portion 5e is in contact with the entire end surface 3e. In the electrode portion 5e, the first electrode layer E1 is in direct contact with the end surface 3e.
The second electrode layer E2 of the electrode portion 5e is disposed on the first electrode layer E1. In the electrode portion 5e, the second electrode layer E2 covers the first electrode layer E1. In the electrode portion 5e, the second electrode layer E2 is in direct contact with the first electrode layer E1. In the electrode portion 5e, the second electrode layer E2 indirectly covers the end surface 3e such that the first electrode layer E1 is positioned between the second electrode layer E2 and the end surface 3e. The second electrode layer E2 of the electrode portion 5e is positioned on the end surface 3e.
The third electrode layer E3 of the electrode portion 5e is disposed on the second electrode layer E2. In the electrode portion 5e, the third electrode layer E3 covers the second electrode layer E2. In the electrode portion 5e, the third electrode layer E3 is in contact with the second electrode layer E2. In the electrode portion 5e, the third electrode layer E3 is in direct contact with the second electrode layer E2. In the 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 the electrode portion 5e is disposed on the third electrode layer E3. In the electrode portion 5e, the fourth electrode layer E4 covers the third electrode layer E3. In the electrode portion 5e, the fourth electrode layer E4 is in contact with the third electrode layer E3. In the electrode portion 5e, the fourth electrode layer E4 is in direct contact with the third electrode layer E3.
The fifth electrode layer E5 of the electrode portion 5e is disposed on the fourth electrode layer E4. In the electrode portion 5e, the fifth electrode layer E5 covers the fourth electrode layer E4. In the electrode portion 5e, the fifth electrode layer E5 is in contact with the fourth electrode layer E4. In the electrode portion 5e, the fifth electrode layer E5 is in direct contact with the fourth electrode layer E4.
In the electrode portion 5e, the third electrode layer E3, the fourth electrode layer E4, and the fifth electrode layer E5 are disposed outside the second electrode layer E2. The fourth electrode layer E4 of the electrode portion 5e is disposed outside the third electrode layer E3 of the electrode portion 5e. The fifth electrode layer E5 of the electrode portion 5e is disposed outside the fourth electrode layer E4 of the electrode portion 5e. The third electrode layer E3, fourth electrode layer E4, and fifth electrode layer E5 of the electrode portion 5e are positioned on the end surface 3e.
The second electrode layer E2 of the electrode portion 5e may cover only a partial region of the end surface 3e. The above-described partial region of the end surface 3e is positioned closer to the side surface 3a, for example. The electrode portion 5c may have the following configuration. The second electrode layer E2 of the electrode portion 5e indirectly covers the above-described partial region of the end surface 3e such that the first electrode layer E1 is positioned between the second electrode layer E2 and the end surface 3e. The second electrode layer E2 of the electrode portion 5e directly covers only a partial region of a portion, of the first electrode layer E1, positioned on the end surface 3e. The electrode portion 5e includes a region in which the first electrode layer E1 is exposed from the second electrode layer E2 and a region in which the first electrode layer E1 is covered with the second electrode layer E2.
The first electrode layer E1 is formed from sintering electrically conductive paste applied onto the surface of the element body 3. The electrically conductive paste is applied onto the end surface 3e, the ridge portion between the side surface 3a and the end surface 3e, and the ridge portion between the side surface 3c and the end surface 3e. The first electrode layer E1 is formed to cover the end surface 3e, the ridge portion between the side surface 3a and the end surface 3e, and the ridge portion between the side surface 3c and the end surface 3e. The first electrode layer E1 is formed from sintering a metal component (metal particles) included in the electrically conductive paste. The first electrode layer E1 includes a sintered metal layer. The first electrode layer E1 includes the sintered metal layer formed on the element body 3. For example, the first electrode layer E1 includes a sintered metal layer made of copper. The first electrode layer E1 may include a sintered metal layer made of nickel. The first electrode layer E1 includes a base metal. The electrically conductive paste includes, for example, particles 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, 5c, and 5e are formed integrally with each other.
The second electrode layer E2 is formed from curing electrically conductive resin paste applied onto the first electrode layer E1. The electrically conductive resin paste is applied onto the first electrode layer E1 and the partial regions of the side surfaces 3a and 3c. The second electrode layer E2 is formed on over the first electrode layer E1 and the element body 3. The electrically conductive resin paste includes, for example, a plurality of silver particles, a resin, and an organic solvent. The resin includes, for example, a thermosetting resin. The thermosetting resin is, for example, a phenol resin, an acrylic resin, a silicone resin, an epoxy resin, or a polyimide resin. The second electrode layer E2 is in contact with a part of the ridge portion between the side surface 3a and the side surface 3c. The second electrode layers E2 included in the electrode portions 5a, 5c, and 5e are integrally formed with each other.
The second electrode layer E2 includes a conductive resin layer covering the first electrode layer E1. As illustrated in
The third electrode layer E3 is formed on the second electrode layer E2 through a plating method. In the multilayer capacitor C1, the third electrode layer E3 is formed on the second electrode layer E2 through copper-plating. The third electrode layer E3 includes a copper plating layer. The third electrode layer E3 includes copper. The metal included in the third electrode layer E3 is not limited to copper. The third electrode layer E3 may include a metal that volumetrically expand due to oxidation. The third electrode layer E3 covers the second electrode layer E2.
The fourth electrode layer E4 is formed on the third electrode layer E3 through a plating method. In the multilayer capacitor C1, the fourth electrode layer E4 is formed on the third electrode layer E3 through nickel-plating. The fourth electrode layer E4 includes a nickel plating layer. The fourth electrode layer E4 includes nickel. The nickel plating layer has better solder leach resistance than the silver particle 13 included in the second electrode layer E2. The fourth electrode layer E4 covers the third electrode layer E3. The fourth electrode layer E4 includes an other metal plating layer different from the third electrode layer E3.
The fifth electrode layer E5 is formed on the fourth electrode layer E4 through a plating method. The fifth electrode layer E5 includes a solder plating layer. In the multilayer capacitor C1, the fifth electrode layer E5 is formed on the fourth electrode layer E4 through tin-plating. The fifth electrode layer E5 includes a tin plating layer. The fifth electrode layer E5 includes tin (Sn). The fifth electrode layer E5 may include 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 fifth electrode layer E5 covers the fourth electrode layer E4. The fifth electrode layer E5 includes an other metal plating layer different from the third electrode layer E3.
The third electrode layer E3, the fourth electrode layer E4, and the fifth electrode layer E5 are included in a metal plating layer PL formed on the second electrode layer E2. That is, the external electrode 5 includes the metal plating layer PL, and the metal plating layer PL includes the third electrode layer E3, the fourth electrode layer E4, and the fifth electrode layer E5. The metal plating layer PL covers the second electrode layer E2. The third electrode layers E3 included in the electrode portions 5a, 5c, and 5e are formed integrally with each other. The fourth electrode layers E4 included in the electrode portions 5a, 5c, and 5e are formed integrally with each other. The fifth electrode layers E5 included in the electrode portions 5a, 5c, and 5e are formed integrally with each other.
The metal plating layer PL covering the second electrode layer E2 tends to be in close contact with the second electrode layer E2, but tends not to be in close contact with the element body 3. Therefore, the above-described gap is present between each end of the third electrode layer E3, the fourth electrode layer E4 and the fifth electrode layer E5 and the side surfaces 3a and 3c. The gap is present between each end of the third electrode layer E3, the fourth electrode layer E4 and the fifth electrode layer E5 and the ridge portion between the side surface 3a and the side surface 3c. An interval between each end of the third electrode layer E3, the fourth electrode layer E4, and the fifth electrode layer E5 and the side surfaces 3a and 3c, that is, a width of the above-described gap, is greater than 0 and equal to or less than 3 μm, for example. A width of the gap between each end of the third electrode layer E3, the fourth electrode layer E4 and the fifth electrode layer E5 and the ridge portion between the side surface 3a and the side surface 3c is, for example, greater than 0 and equal to or less than 3 μm. The widths of the gaps may be different for each of the third electrode layer E3, the fourth electrode layer E4, and the fifth electrode layer E5, or may be different for each of the side surface 3a, the side surface 3c, and the ridge portion between the side surface 3a and the side surface 3c.
As illustrated in
The portion 15a is positioned on the side surface 3a. The portion 15a is in contact with the end of the third electrode layer E3 and the side surface 3a and is disposed in the gap between the end of the third electrode layer E3 and the side surface 3a. For example, the portion 15a closes the gap between the end of the third electrode layer E3 and the side surface 3a.
The portion 15c is positioned on the side surface 3c. The portion 15c is in contact with the end of the third electrode layer E3 and the side surface 3c and is disposed in the gap between the end of the third electrode layer E3 and the side surface 3c. For example, the portion 15c closes the gap between the end of the third electrode layer E3 and the side surface 3c.
The oxide 15 includes a portion positioned on the ridge portion between the side surface 3a and the side surface 3c. This portion is in contact with the end of the third electrode layer E3 and the ridge portion between the side surface 3a and the side surface 3c and is disposed in the gap between the end of the third electrode layer E3 and the ridge portion between the side surface 3a and the side surface 3c. For example, the portion positioned on the ridge portion between the side surface 3a and the side surface 3c closes the gap between the end of the third electrode layer E3 and the ridge portion between the side surface 3a and the side surface 3c.
As illustrated in
As illustrated in
The above-described portion positioned on the ridge portion between the side surface 3a and the side surface 3c extends along an edge of the second electrode layer E2 of the electrode portion on the ridge portion between the side surface 3a and the side surface 3c. For example, the above-described portion positioned on the ridge portion between the side surface 3a and the side surface 3c extends continuously along the edge of the second electrode layer E2 of the electrode portion on the ridge portion between the side surface 3a and the side surface 3c. The above-described portion positioned on the ridge portion between the side surface 3a and the side surface 3c may be in contact with the second electrode layer E2 of the electrode portion on the ridge portion between the side surface 3a and the side surface 3c or may be separated from the second electrode layer E2 of the electrode portion on the ridge portion between the side surface 3a and the side surface 3c.
The oxide 15 includes an oxide of a metal component included in the metal plating layer PL. In the multilayer capacitor C1, the oxide 15 includes an oxide of copper included in the third electrode layer E3. For example, the oxide 15 includes a copper oxide.
The oxide 15 is formed from, for example, heat treatment of the third electrode layer E3. In the heat treatment of the third electrode layer E3, for example, the following process proceeds.
An oxide of copper included in the third electrode layer E3 is formed on a surface of the end of the third electrode layer E3. The oxide of copper formed on the surface of the end of the third electrode layers E3 grows toward the element body 3 in the gap between the end of the third electrode layers E3 and the element body 3. The oxide of copper that grows in the gap between the end of the third electrode layer E3 and the element body 3 grows until coming into contact with the element body 3. Conditions for the heat treatment of the third electrode layer E3 include, for example, heating temperature or heating time.
The heat treatment of the third electrode layer E3 may be performed after forming the fourth electrode layer E4 and before forming the fifth electrode layer E5. In this case, an oxide of nickel included in the fourth electrode layer E4 may be formed on a surface of the end of the fourth electrode layer E4. Nickel oxide tends to form a passive film and tends not to grow than copper oxide. Therefore, the gap tends to be present between the fourth electrode layer E4 and the element body 3.
The heat treatment of the third electrode layer E3 may be performed after forming the fifth electrode layer E5. In this case, an oxide of metal included in the fifth electrode layer E5, for example, an oxide of tin, may be formed on a surface of the end of the fifth electrode layer E5. The oxide of tin tends to form a passive film and tends not to grow than copper oxide. Therefore, the gap tends to be present between the fifth electrode layer E5 and the element body 3.
In the multilayer capacitor C1 the oxide 15 is in contact with the metal plating layer PL and the element body 3 and is disposed in the gap between the metal plating layer PL and the element body 3. Therefore, even when silver (Ag) migration occurs in the second electrode layer E2, progress of silver migration is prevented. The multilayer capacitor C1 prevents the progress of silver migration on the element body 3.
The oxide 15 includes the oxide of the metal component included in the metal plating layer PL. Therefore, in the multilayer capacitor C1, the oxide 15 is reliably disposed in the gap between the metal plating layer PL and the element body 3.
In the multilayer capacitor C1, the metal plating layer PL includes the third electrode layer E3. The oxide 15 includes the oxide of copper included in the third electrode layer E3.
In the multilayer capacitor C1, for example, the oxide 15 may be formed from heat treating the third electrode layer E3. Therefore, the oxide 15 is easily disposed.
In the multilayer capacitor C1, the metal plating layer PL includes the fourth electrode layer E4. The fourth electrode layer E4 includes the other metal plating layer different from the third electrode layer E3.
The fourth electrode layer E4 has the gap between the fourth electrode layer E4 and the element body 3. Heat tends to act on the third electrode layer E3 through the gap between the fourth electrode layer E4 and the element body 3 when heat-treating the third electrode layer E3, for example. Therefore, even in the configuration in which the metal plating layer PL includes the fourth electrode layer E4, the oxide 15 may be easily and reliably disposed.
In the multilayer capacitor C1, the metal plating layer PL includes the fourth electrode layer E4.
The fourth electrode layer E4 prevents solder leaching when solder-mounting.
In the multilayer capacitor C1, the metal plating layer PL includes the fifth electrode layer E5.
The fifth electrode layer E5 improves solder-mountability of the multilayer capacitor C1.
In the multilayer capacitor C1, the metal plating layer PL includes the fifth electrode layer E5. The fifth electrode layer E5 includes the other metal plating layer different from the third electrode layer E3.
The fifth electrode layer E5 has the gap between the fifth electrode layer E5 and the element body 3. Heat tends to act on the third electrode layer E3 through the gap between the fifth electrode layer E5 and the element body 3 when heat-treating the third electrode layer E3, for example. Therefore, even in the configuration in which the metal plating layer PL includes the fifth electrode layer E5, the oxide 15 may be easily and reliably disposed.
In the multilayer capacitor C1, the oxide 15 extends along the edge of the second electrode layer E2. Therefore, the multilayer capacitor C1 reliably prevents the progress of silver migration.
In the present specification, in a case where an element is described as being disposed on another element, the element may be directly disposed on the other element or be indirectly disposed on the other element. In a case where an element is indirectly disposed on another element, an intervening element is present between the element and the other element. In a case where an element is directly disposed on another element, no intervening element is present between the element and the other element.
In the present specification, in a case where an element is described as being positioned on another element, the element may be directly positioned on the other element or be indirectly positioned on the other element. In a case where an element is indirectly positioned on another element, an intervening element is present between the element and the other element. In a case where an element is directly positioned on another element, no intervening element is present between the element and the other element.
In the present specification, in a case where an element is described as covering another element, the element may directly cover the other element or indirectly cover the other element. In a case where an element indirectly covers another element, an intervening element is present between the element and the other element. In a case where an element directly covers another element, no intervening element is present between the element and the other element.
It is to be understood that not all aspects, advantages and features described herein may necessarily be achieved by, or included in, any one particular example. Indeed, having described and illustrated various examples herein, it should be apparent that other examples may be modified in arrangement and detail.
As illustrated in
In a configuration in which the metal plating layer PL includes the sixth electrode layer E6, the sixth electrode layer E6 is disposed on the second electrode layer E2. The sixth electrode layer E6 covers the second electrode layer E2. The sixth electrode layer E6 is in contact with the second electrode layer E2. The sixth electrode layer E6 is in direct contact with the second electrode layer E2.
The third electrode layer E3 is disposed on the sixth electrode layer E6. The third electrode layer E3 is disposed outside the second electrode layer E2. The third electrode layer E3 covers the sixth electrode layer E6. The third electrode layer E3 is in contact with the sixth electrode layer E6. The third electrode layer E3 is in direct contact with the sixth electrode layer E6. The third electrode layer E3 is formed on the sixth electrode layer E6 through the plating method.
The sixth electrode layer E6 is formed on the second electrode layer E2 through a plating method. The fourth electrode layer E4 is formed on the second electrode layer E2 through nickel-plating, for example. The sixth electrode layer E6 includes a nickel plating layer.
A gap is present between an end of the sixth electrode layer E6 and the element body 3 in the same manner as between the end of each of the third electrode layer E3, the fourth electrode layer E4, and the fifth electrode layer E5 and the element body 3. That is, the gap is present between the edge of the sixth electrode layer E6 and the side surfaces 3a and 3c and between the edge of the sixth electrode layer E6 and the ridge portion between the side surface 3a and the side surface 3c. An interval between the end of the sixth electrode layer E6 and the side surfaces 3a and 3c, that is, a width of the above-described gap, is greater than 0 and equal to or less than 3 μm, for example. A width of the gap between the end of the sixth electrode layer E6 and the ridge portion between the side surface 3a and the side surface 3c is, for example, greater than 0 and equal to or less than 3 μm.
The width of the gap between the end of the sixth electrode layer E6 and the element body 3 may be the same as or different from the width of the gap between each end of the third electrode layer E3, the fourth electrode layer E4, and the fifth electrode layer E5 and the element body 3. The width of the gap between the end of the sixth electrode layer E6 and the side surface 3a, the width of the gap between the end of the sixth electrode layer E6 and the side surface 3c, and the width of the gap between the end of the sixth electrode layer E6 and the ridge portion between the side surface 3a and the side surface 3c may be the same as or different from each other.
In the present examples and modified examples, the electronic component includes the multilayer capacitor. However, applicable electronic component is not limited to the multilayer capacitor. The applicable electronic component includes, for example, a multilayer electronic component such as a multilayer inductor, a multilayer varistor, a multilayer piezoelectric actuator, a multilayer thermistor, a multilayer solid-state battery component, or a multilayer composite component, or electronic components other than the multilayer electronic components.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-135287 | Aug 2023 | JP | national |
