The present invention relates to a coil component and a method for manufacturing a coil component.
Patent Literature 1 (Japanese Unexamined Patent Publication No. 2018-190490) discloses an electronic component including a ceramic multilayer body, an internal electrode layer disposed in the ceramic multilayer body, and an external electrode disposed on the surface of the ceramic multilayer body. In the electronic component described in Patent Literature 1, the external electrode has an external electrode layer disposed on the surface of the ceramic multilayer body and a plating layer disposed on the external electrode layer.
In manufacturing a coil component in which an external electrode has an electrode layer and a plating layer, the plating layer is formed on the electrode layer after the electrode layer is formed on an element body. In forming the plating layer, the edge of the electrode layer formed on the surface of the element body may peel off due to the stress that is generated during the plating layer formation.
An object of one aspect of the present invention is to provide a coil component and a method for manufacturing a coil component capable of suppressing peeling of an external electrode.
A coil component according to one aspect of the present invention includes: an element body; a coil disposed in the element body; and an external electrode disposed on a surface of the element body, in which the external electrode has a first electrode layer disposed on the surface of the element body and a plating layer disposed on the first electrode layer, and the plating layer is disposed so as to be scattered in a plurality of places on an edge of the first electrode layer.
In the coil component according to one aspect of the present invention, the plating layer is disposed so as to be scattered in a plurality of places on the edge of the first electrode layer. In this manner, in the coil component, the plating layer is disposed so as to be scattered in a plurality of places not at the edge of the first electrode layer as a whole but on the edge of the first electrode layer, and thus the stress that is generated when the plating layer is formed can be dispersed. Accordingly, in the coil component, the first electrode layer peeling off the element body can be suppressed. Accordingly, in the coil component, peeling of the external electrode can be suppressed.
In one embodiment, the external electrode may have a second electrode layer disposed on the first electrode layer, the second electrode layer may contain a resin and may not be disposed at the edge of the first electrode layer, and the plating layer may be disposed on the first electrode layer and the second electrode layer. In this configuration, the edge of the first electrode layer is not covered with the second electrode layer, and thus the plating layer is disposed so as to be scattered in a plurality of places on the edge of the first electrode layer. Accordingly, the first electrode layer peeling off the element body can be suppressed. In addition, the second electrode layer contains a resin. As a result, in the second electrode layer, the stress in forming the plating layer can be mitigated. Accordingly, it is possible to suppress the second electrode layer peeling off the first electrode layer due to the stress in forming the plating layer.
In one embodiment, the external electrode may have a second electrode layer disposed on the first electrode layer, the second electrode layer may have no glass component on a surface as compared with the first electrode layer and may not be disposed at the edge of the first electrode layer, and the plating layer may be disposed on the first electrode layer and the second electrode layer. In this configuration, the edge of the first electrode layer is not covered with the second electrode layer, and thus the plating layer is disposed so as to be scattered in a plurality of places on the edge of the first electrode layer. Accordingly, the first electrode layer peeling off the element body can be suppressed. In addition, the second electrode layer has no glass component on the surface as compared with the first electrode layer. Accordingly, the plating layer can be continuously and uniformly formed on the second electrode layer.
In one embodiment, the element body may be configured by stacking a magnetic body layer containing a plurality of metal magnetic particles of a soft magnetic material.
A method for manufacturing a coil component according to one aspect of the present invention is a method for manufacturing a coil component including an element body, a coil disposed in the element body, and an external electrode disposed on a surface of the element body, in which an electrode layer disposed on the surface of the element body and a plating layer disposed on the electrode layer are provided, and the plating layer is formed on an edge of the electrode layer such that the plating layer is scattered in a plurality of places.
In the coil component manufacturing method according to one aspect of the present invention, the plating layer is formed on the edge of the electrode layer such that the plating layer is scattered in a plurality of places. In this manner, in the coil component manufacturing method, the plating layer is formed so as to be scattered in a plurality of places not at the edge of the electrode layer as a whole but on the edge of the first electrode layer, and thus the stress that is generated when the plating layer is formed can be dispersed. Accordingly, in the coil component manufacturing method, the electrode layer peeling off the element body can be suppressed. Accordingly, in the coil component manufacturing method, peeling of the external electrode can be suppressed in the coil component.
According to one aspect of the present invention, peeling of the external electrode can be suppressed.
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the description of the drawings, the same or equivalent elements are denoted by the same reference numerals with redundant description omitted.
As illustrated in
The element body 2 has a rectangular parallelepiped shape. The rectangular parallelepiped shape includes the shape of a rectangular parallelepiped with chamfered corner and ridge portions and the shape of a rectangular parallelepiped with rounded corner and ridge portions. The element body 2 has, as the outer surfaces thereof, a pair of end surfaces 2a and 2b facing each other, a pair of main surfaces 2c and 2d facing each other, and a pair of side surfaces 2e and 2f facing each other. The facing direction in which the pair of main surfaces 2c and 2d face each other is a first direction D1. The facing direction in which the pair of end surfaces 2a and 2b face each other is a second direction D2. The facing direction in which the pair of side surfaces 2e and 2f face each other is a third direction D3. In the present embodiment, the first direction D1 is the height direction of the element body 2. The second direction D2 is the longitudinal direction of the element body 2 and is orthogonal to the first direction D1. The third direction D3 is the width direction of the element body 2 and is orthogonal to the first direction D1 and the second direction D2.
The pair of end surfaces 2a and 2b extend in the first direction D1 so as to interconnect the pair of main surfaces 2c and 2d. The pair of end surfaces 2a and 2b also extend in the third direction D3 (short side direction of the pair of main surfaces 2c and 2d). The pair of side surfaces 2e and 2f extend in the first direction D1 so as to interconnect the pair of main surfaces 2c and 2d. The pair of side surfaces 2e and 2f also extend in the second direction D2 (long side direction of the pair of end surfaces 2a and 2b). The main surface 2d can be defined as a mounting surface facing another electronic device when the multilayer coil component 1 is mounted on the electronic device (for example, a circuit board or an electronic component).
As illustrated in
Each magnetic body layer 6 contains a plurality of metal magnetic particles. The metal magnetic particles are configured from a soft magnetic alloy (soft magnetic material). The soft magnetic alloy is, for example, a Fe—Si-based alloy. In a case where the soft magnetic alloy is a Fe—Si-based alloy, the soft magnetic alloy may contain P. The soft magnetic alloy may be, for example, a Fe—Ni—Si-M-based alloy. “M” contains one or more elements selected from Co, Cr, Mn, P, Ti, Zr, Hf, Nb, Ta, Mo, Mg, Ca, Sr, Ba, Zn, B, Al, and rare-earth elements.
The metal magnetic particles are bonded to each other in the magnetic body layer 6. The bond between the metal magnetic particles is realized by, for example, the bond between the oxide films formed on the surfaces of the metal magnetic particles. In the magnetic body layer 6, the metal magnetic particles are electrically insulated from each other by the bond between the oxide films. The thickness of the oxide film is, for example, 5 to 60 nm or less. The oxide film may be configured by one or more layers.
The element body 2 contains a resin. The resin is present between the plurality of metal magnetic particles. The resin is an electrically insulating resin (insulating resin). The insulating resin includes, for example, a silicone resin, a phenol resin, an acrylic resin, or an epoxy resin.
As illustrated in
The first external electrode 4 is disposed on one end surface 2a side. The first external electrode 4 includes the five electrode parts of a first electrode part 4a positioned on the end surface 2a, a second electrode part 4b positioned on the main surface 2c, a third electrode part 4c positioned on the main surface 2d, a fourth electrode part 4d positioned on the side surface 2e, and a fifth electrode part 4e positioned on the side surface 2f. The first electrode part 4a and the second electrode part 4b, the third electrode part 4c, the fourth electrode part 4d, and the fifth electrode part 4e are connected in the ridge portion of the element body 2 and are electrically interconnected. The first external electrode 4 is formed on the five surfaces of one end surface 2a, the pair of main surfaces 2c and 2d, and the pair of side surfaces 2e and 2f. The first electrode part 4a, the second electrode part 4b, the third electrode part 4c, the fourth electrode part 4d, and the fifth electrode part 4e are integrally formed.
As illustrated in
The first electrode layer 40 is formed on the five surfaces of one end surface 2a, the pair of main surfaces 2c and 2d, and the pair of side surfaces 2e and 2f. The first electrode layer 40 contains a conductive material (for example, Ag or Pd). The first electrode layer 40 is configured as a sintered body of a conductive paste containing a conductive metal powder (for example, Ag powder or Pd powder) and glass frit.
The second electrode layer 41 is formed on the first electrode layer 40. The second electrode layer 41 is disposed on the first electrode layer 40 formed on the five surfaces of one end surface 2a, the pair of main surfaces 2c and 2d, and the pair of side surfaces 2e and 2f. The second electrode layer 41 is a conductive resin layer. A thermosetting resin mixed with, for example, a conductive material and an organic solvent is used as the conductive resin. A conductive filler or the like is used as the conductive material. The conductive filler is a metal powder. Ag powder or the like is used as the metal powder. A phenol resin, an acrylic resin, a silicone resin, an epoxy resin, a polyimide resin, or the like is used as the thermosetting resin.
The first plating layer 42 is disposed so as to cover a part of the first electrode layer 40 and the second electrode layer 41. The first plating layer 42 is formed on the five surfaces of one end surface 2a, the pair of main surfaces 2c and 2d, and the pair of side surfaces 2e and 2f. The first plating layer 42 is a Ni plating layer formed by Ni plating.
The second plating layer 43 is disposed so as to cover the first plating layer 42. The second plating layer 43 is formed on the five surfaces of one end surface 2a, the pair of main surfaces 2c and 2d, and the pair of side surfaces 2e and 2f. The second plating layer 43 is a Sn plating layer formed by Sn plating.
In the first external electrode 4, the second electrode layer 41 is not disposed on an edge 40E of the first electrode layer 40. In other words, the edge 40E of the first electrode layer 40 is not covered with the second electrode layer 41. The edge 40E of the first electrode layer 40 is positioned closer to the middle side (inside) of the element body 2 in the second direction D2 than the second electrode layer 41. The edge 40E of the first electrode layer 40 protrudes to the end surface 2b side of the element body 2 beyond the second electrode layer 41 in the second direction D2. In other words, an edge 41E of the second electrode layer 41 is retracted to the end surface 2a side of the element body 2 beyond the edge 40E of the first electrode layer 40 in the second direction D2. The edge 40E of the first electrode layer 40 is a part that includes the tip on the end surface 2b side of the element body 2 and is exposed without being covered with the second electrode layer 41. For example, the edge 40E of the first electrode layer 40 is the part of approximately ¼ of the length in the second direction D2 of the first electrode layer 40 disposed on the main surface 2c of the element body 2. It should be noted that although
The first plating layer 42 and the second plating layer 43 are disposed on a part of the edge 40E of the first electrode layer 40. In other words, the first plating layer 42 and the second plating layer 43 are not disposed on a part of the edge 40E of the first electrode layer 40. As illustrated in
The first plating layer 42 and the second plating layer 43 are disposed on the second electrode layer 41. As illustrated in
Accordingly, on the second electrode layer 41, even if a resin is deposited, the second electrode layer 41 is formed so as to cover the resin so as to be spread over (bridge) the part where the resin is not deposited. As a result, the first plating layer 42 and the second plating layer 43 are continuously and uniformly formed on the second electrode layer 41.
The first electrode layer 40 and the second electrode layer 41 are joined with a predetermined strength by the anchor effect attributable to the unevenness of the boundary between the first electrode layer 40 and the second electrode layer 41.
As illustrated in
As illustrated in
The first electrode layer 50 is formed on the five surfaces of one end surface 2b, the pair of main surfaces 2c and 2d, and the pair of side surfaces 2e and 2f. The first electrode layer 50 contains a conductive material (for example, Ag or Pd). The first electrode layer 50 is configured as a sintered body of a conductive paste containing a conductive metal powder (for example, Ag powder or Pd powder) and glass frit.
The second electrode layer 51 is formed on the first electrode layer 50. The second electrode layer 51 is disposed on the first electrode layer 50 formed on the five surfaces of one end surface 2b, the pair of main surfaces 2c and 2d, and the pair of side surfaces 2e and 2f. The second electrode layer 51 is a conductive resin layer. A thermosetting resin mixed with, for example, a conductive material and an organic solvent is used as the conductive resin. A conductive filler or the like is used as the conductive material. The conductive filler is a metal powder. Ag powder or the like is used as the metal powder. A phenol resin, an acrylic resin, a silicone resin, an epoxy resin, a polyimide resin, or the like is used as the thermosetting resin.
The first plating layer 52 is disposed so as to cover a part of the first electrode layer 50 and the second electrode layer 51. The first plating layer 52 is formed on the five surfaces of one end surface 2b, the pair of main surfaces 2c and 2d, and the pair of side surfaces 2e and 2f. The first plating layer 52 is a Ni plating layer formed by Ni plating.
The second plating layer 53 is disposed so as to cover the first plating layer 52. The second plating layer 53 is formed on the five surfaces of one end surface 2b, the pair of main surfaces 2c and 2d, and the pair of side surfaces 2e and 2f. The second plating layer 53 is a Sn plating layer formed by Sn plating.
In the second external electrode 5, the second electrode layer 51 is not disposed on an edge 50E of the first electrode layer 50. In other words, the edge 50E of the first electrode layer 50 is not covered with the second electrode layer 51. The edge 50E of the first electrode layer 50 is positioned closer to the middle side (inside) of the element body 2 in the second direction D2 than the second electrode layer 51. The edge 50E of the first electrode layer 50 protrudes to the end surface 2a side of the element body 2 beyond the second electrode layer 51 in the second direction D2. In other words, an edge 51E of the second electrode layer 51 is retracted to the end surface 2b side of the element body 2 beyond the edge 50E of the first electrode layer 50 in the second direction D2. The edge 50E of the first electrode layer 50 is a part that includes the tip on the end surface 2a side of the element body 2 and is exposed without being covered with the second electrode layer 51. For example, the edge 50E of the first electrode layer 50 is the part of approximately ¼ of the length in the second direction D2 of the first electrode layer 50 disposed on the main surface 2c of the element body 2. It should be noted that although
The first plating layer 52 and the second plating layer 53 are disposed on a part of the edge 50E of the first electrode layer 50. In other words, the first plating layer 52 and the second plating layer 53 are not disposed on a part of the edge 50E of the first electrode layer 50. As illustrated in
The first plating layer 52 and the second plating layer 53 are disposed on the second electrode layer 51. The first plating layer 52 and the second plating layer 53 are continuously and uniformly formed on the second electrode layer 51. Although a resin can be deposited on the surface of the second electrode layer 51 as well, the region (area) of the resin is smaller than that of the glass layer 50G and is present substantially uniformly on the surface of the second electrode layer 51, and thus the inter-resin distance is short. Accordingly, on the second electrode layer 51, even if a resin is deposited, the second electrode layer 51 is formed so as to cover the resin so as to be spread over (bridge) the part where the resin is not deposited. As a result, the first plating layer 52 and the second plating layer 53 are continuously and uniformly formed on the second electrode layer 51.
The first electrode layer 50 and the second electrode layer 51 are joined with a predetermined strength by the anchor effect attributable to the unevenness of the boundary between the first electrode layer 50 and the second electrode layer 51.
In the multilayer coil component 1, a coil 8 is disposed in the element body 2 as illustrated in
The coil conductors 10, 11, 12, 13, 14, and 15, the first connecting conductor 16, and the second connecting conductor 17 are made of a conductive material usually used as a conductor of a coil (for example, Ni or Cu). The coil conductors 10, 11, 12, 13, 14, and 15, the first connecting conductor 16, and the second connecting conductor 17 are configured as a sintered body of a conductive paste containing the above conductive material.
A method for manufacturing the multilayer coil component 1 will be described below.
Slurry is prepared by mixing, for example, metal magnetic particles, an insulating resin, and a solvent. The prepared slurry is applied onto a base material (such as a PET film) by the doctor blade method to form a green sheet to become the magnetic body layer 6. Next, a through hole is formed by laser machining at the position on the green sheet where a through hole conductor is to be formed.
Subsequently, the through hole in the green sheet is filled with a first conductive paste. The first conductive paste is prepared by mixing, for example, a conductive metal powder and a binder resin. Subsequently, conductors to become the coil conductors 10, 11, 12, 13, 14, and 15, the first connecting conductor 16, and the second connecting conductor 17 are provided on the green sheet. At this time, the conductor is connected to the conductive paste in the through hole.
Subsequently, the green sheet is stacked. Here, a plurality of the conductor-including green sheets are peeled off the base material, stacked, and pressurized in the stacking direction to form a multilayer body. At this time, each green sheet is stacked such that the conductors to become the coil conductors 10, 11, 12, 13, 14, and 15, the first connecting conductor 16, and the second connecting conductor 17 overlap in the stacking direction.
Subsequently, the multilayer body of the green sheets is cut into chips of a predetermined size with a cutting machine to obtain green chips. Subsequently, after removing the binder resin contained in each portion from the green chip, the green chip is fired. As a result, the element body 2 is obtained.
Subsequently, a second conductive paste is provided with respect to each of the sides of the pair of end surfaces 2a and 2b of the element body 2. The second conductive paste is prepared by mixing, for example, a conductive metal powder, glass frit, and a binder resin. Subsequently, the second conductive paste is baked by heat treatment and the first electrode layers 40 and 50 are formed. As a result of the heat treatment, the glass layers 40G and 50G are deposited on a part of the surfaces of the first electrode layers 40 and 50.
Subsequently, a third conductive paste is provided on the first electrode layers 40 and 50. The third conductive paste is prepared by mixing a thermosetting resin with, for example, a conductive material and an organic solvent. The third conductive paste is provided so as not to cover the edges 40E and 50E of the first electrode layers 40 and 50. Subsequently, the third conductive paste is baked by heat treatment and the second electrode layers 41 and 51 are formed. Finally, the surfaces of the first electrode layers 40 and 50 and the second electrode layers 41 and 51 are plated to form the first plating layers 42 and 52 and the second plating layers 43 and 53. The multilayer coil component 1 is obtained as a result of the above steps.
As described above, in the multilayer coil component 1 according to the present embodiment, the first plating layers 42 and 52 and the second plating layers 43 and 53 are disposed so as to be scattered in a plurality of places on the edges 40E and 50E of the first electrode layers 40 and 50. In this manner, in the multilayer coil component 1, the first plating layers 42 and 52 and the second plating layers 43 and 53 are disposed so as to be scattered in a plurality of places not at the edges 40E and 50E of the first electrode layers 40 and 50 as a whole but on the edges 40E and 50E of the first electrode layers 40 and 50, and thus the stress that is generated when the first plating layers 42 and 52 and the second plating layers 43 and 53 are formed can be dispersed. Accordingly, in the multilayer coil component 1, the first electrode layers 40 and 50 peeling off the element body 2 can be suppressed. Accordingly, in the multilayer coil component 1, peeling of the first external electrode 4 and the second external electrode 5 can be suppressed.
In the multilayer coil component 1 according to the present embodiment, the first external electrode 4 has the second electrode layer 41 disposed on the first electrode layer 40 and the second external electrode 5 has the second electrode layer 41 disposed on the first electrode layer 50. The second electrode layers 41 and 51 contain a resin and are not disposed at the edges 40E and 50E of the first electrode layers 40 and 50. The first plating layers 42 and 52 and the second plating layers 43 and 53 are disposed on the first electrode layers 40 and 50 and the second electrode layers 41 and 51. In this configuration, the edges 40E and 50E of the first electrode layers 40 and 50 are not covered with the second electrode layers 41 and 51, and thus the first plating layers 42 and 52 and the second plating layers 43 and 53 are disposed so as to be scattered in a plurality of places on the edges 40E and 50E of the first electrode layers 40 and 50. Accordingly, the first electrode layers 40 and 50 peeling off the element body 2 can be suppressed. In addition, the second electrode layers 41 and 51 contain a resin. As a result, in the second electrode layers 41 and 51, the stress in forming the first plating layers 42 and 52 and the second plating layers 43 and 53 can be mitigated. Accordingly, it is possible to suppress the second electrode layers 41 and 51 peeling off the first electrode layers 40 and 50 due to the stress in forming the first plating layers 42 and 52 and the second plating layers 43 and 53.
Although an embodiment of the present invention has been described above, the present invention is not necessarily limited to the above embodiment and various modifications can be made without departing from the gist thereof.
The element body 2 does not necessarily have to be configured to contain metal magnetic particles and may be configured by ferrite (such as Ni—Cu—Zn-based ferrite, Ni—Cu—Zn—Mg-based ferrite, and Cu—Zn-based ferrite), a dielectric material, or the like.
In the above embodiment, a form in which the first external electrode 4 has the first electrode part 4a, the second electrode part 4b, the third electrode part 4c, the fourth electrode part 4d, and the fifth electrode part 4e has been described as an example. However, the first external electrode 4 may have only the first electrode part 4a or only the second electrode part 4b. Likewise, the second external electrode 5 may have only the first electrode part 5a or only the second electrode part 5b. Various shapes can be adopted for the first external electrode 4 and the second external electrode 5.
In the above embodiment, a form in which the first external electrode 4 has the first electrode layer 40 and the second electrode layer 41 has been described as an example. However, the first external electrode may lack the second electrode layer. The same applies to the second external electrode.
In the above embodiment, a form in which the second electrode layers 41 and 51 are conductive resin layers has been described as an example. However, the second electrode layers 41 and 51 may not be conductive resin layers. In this case, it is preferable that the second electrode layer has no glass component (glass layer) on the surface as compared with the first electrode layer. In this configuration, a plating layer can be continuously and uniformly formed on the second electrode layer.
In the above embodiment, a form in which the first plating layers 42 and 52 and the second plating layers 43 and 53 are provided as plating layers has been described as an example. However, the plating layer may be one layer or three layers.
The number of coil conductors is not limited to the value described above.
Number | Date | Country | Kind |
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2021-146985 | Sep 2021 | JP | national |