This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2015-146575, filed on Jul. 24, 2015, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a multilayer coil component.
A DC-DC converter mounting thereon a coil component has been used in an electric power source of a mobile communication terminal, etc. A laminated type coil component (multilayer coil component) is used as the above coil component from the standpoints of downsizing, etc. Such a multilayer coil component is disclosed in, for example, Japanese Unexamined Patent Publication No. 2010-192715.
In this regard, when a via hole conductor connecting coil conductors adjacent to each other in a laminated direction is arranged inside a coil formation area in plan view like the multilayer coil component disclosed in Japanese Unexamined Patent Publication No. 2010-192715, an end of the coil conductor connected to the via hole conductor enters inside the coil, substantively reducing the coil inner diameter. Such a reduced coil inner diameter makes it difficult to yield sufficient coil characteristics (for example, inductance and Q-value).
Japanese Unexamined Patent Publication No. 2015-18852 has proposed a technique that prevents reduction of coil inner diameter by disposing a conductive pattern having functions same as those of the via hole conductor in the coil formation area in plan view.
However, in the multilayer coil component disclosed in Japanese Unexamined Patent Publication No. 2015-18852, positions of respective connecting parts connecting the conductor patterns adjacent vertically to each other in the laminated direction are misaligned in plan view. This is because the positions of respective connecting parts need to be misaligned to form the coil wound around along the vertical direction because ends of the upper and lower conductor patterns are overlapped to each other at the connecting part.
When positions of respective connecting parts are misaligned in plan view like the multilayer coil in Japanese Unexamined Patent Publication No. 2015-18852, many types of conductor patterns need to be prepared to match the position of each connecting part. Consequently, labor and time is needed to prepare each conductor pattern, failing to easily manufacture the coil component.
The disclosure provides a multilayer coil component that reduces the number of types of coil part structuring a coil.
A multilayer coil component according to an aspect of the present disclosure is a multilayer coil component having a laminated structure and including a coil in an insulating body, including: a first coil part that structures a part of the coil, extends in a layer structuring the laminated structure, and has a divided portion and a pair of ends formed of a first end and a second end sandwiching the divided portion; a second coil part that structures a part of the coil, extends in a layer structuring the laminated structure, and has a divided portion and a pair of ends, the second coil part being positioned on a lower side of the first coil part in a laminated direction, the divided portion and the pair of ends of the second coil part having shapes same as shapes of the divided portion and the pair of ends of the first coil part and being located at positions same as positions of the divided portion and the pair of ends of the first coil part when viewed from the laminated direction; and a connecting part having a layer shape interposed between the first coil part and the second coil part and extended along the shape of the divided portion of the first coil part to connect the first coil part and the second coil part, wherein in the pairs of ends of the first coil part and the second coil part, the first end has an upper portion and a lower portion in the laminated direction, the upper portion being extended on a side of the second end more than the lower portion, and the second end has an upper portion and a lower portion in the laminated direction, the lower portion being extended on a side of the first end more than the upper portion, and the connecting part is connected only to the second end of the pair of ends of the first coil part on an upper side in the laminated direction, and is connected only to the first end of the pair of ends of the second coil part on a lower side in the laminated direction.
In the above multilayer coil component, even when both pairs of ends of the first coil part and the second coil part are located at the same positions when viewed from the laminated direction and have the same shapes, the connecting part is connected only to the second end of the first coil part on the upper side in the laminated direction, and is connected only to the first end of the second coil part on the lower side in the laminated direction. Thus, for example, when a connecting part is further provided on the upper side of the first coil part or on the lower side of the second coil part, a coil wound around along the laminated direction is structured without misaligning the positions of the respective connecting parts. Consequently, the entire shapes of the respective first coil parts and the second coil parts can be designed to be the exact same shape, which makes it possible to reduce the number of types of coil part, saving labor and time for preparing many types of conductor patterns like the conventional type.
The multilayer coil component may include a plurality of coil parts each structuring a part of the coil, extending in a layer structuring the laminated structure, and having a divided portion and a pair of ends, the divided portion and the pair of ends having shapes same as the shapes of the divided portion and the pair of ends of the first coil part and being located at positions same as the positions of the divided portion and the pair of ends of the first coil part when viewed from the laminated direction, and a plurality of connecting parts alternately aligned with the plurality of the coil parts, each of the plurality of connecting parts being located at a position same as a position of the connecting part when viewed from the laminated direction and having a shape same as a shape of the connecting part. Each of the plurality of connecting parts is connected only to the second end of the pair of ends of a corresponding one of the plurality of coil parts positioned on the upper side in the laminated direction, and is connected only to the first end of the pair of ends of a corresponding one of the plurality of coil parts positioned on the lower side in the laminated direction. In this case, a coil can be structured in which the plurality of coil parts and the plurality of connecting parts are alternately aligned without misaligning the positions of the respective plurality of connecting parts. This makes it possible to design the entire shapes of the respective coil parts to be the exact same shape, reducing the number of types of the coil parts.
A multilayer coil component according to another aspect of the present disclosure is a multilayer coil component having a laminated structure and including a coil in an insulating body, including: a first coil part that structures a part of the coil, extends in a layer structuring the laminated structure, and has a pair of ends formed of a first end and a second end being separated by a predetermined length and opposed to each other; a second coil part that structures a part of the coil, extends in a layer structuring the laminated structure, and has a pair of ends, the second coil part being positioned on a lower side of the first coil part in a laminated direction, the pair of ends of the second coil part having shapes same as shapes of the pair of ends of the first coil part and being located at positions same as positions of the pair of ends of the first coil part when viewed from the laminated direction; and a connecting part having a layer shape interposed between the first coil part and the second coil part and extended along an opposing direction of the pair of ends to connect the first coil part and the second coil part, wherein in each of the pairs of ends of the first coil part and the second coil part, given that an upper end position and a lower end position of the first end in the laminated direction are an a point and a b point, respectively, and an upper end position and a lower end position of the second end in the laminated direction are a c point and a d point, respectively, in a vertical section parallel to the opposing direction of the pair of ends, the b point, the a point, the d point, and the c point are aligned without overlapping in this order from a side of the first end in the opposing direction, a length D of the connecting part is longer than a separation distance between the a point and the d point, and shorter than a separation distance between the b point and the c point in the opposing direction, and the connecting part is connected only to the second end of the pair of ends of the first coil part on an upper side in the laminated direction, and is connected only to the first end of the pair of ends of the second coil part on a lower side in the laminated direction.
In the above multilayer coil component, even when both pairs of ends of the first coil part and the second coil part are located at the same positions when viewed from the laminated direction and have the same shapes, the connecting part is connected only to the second end of the first coil part on the upper side in the laminated direction, and is connected only to the first end of the second coil part on the lower side in the laminated direction. Thus, for example, when a connecting part is further provided on the upper side of the first coil part or on the lower side of the second coil part, a coil wound around along the laminated direction is structured without misaligning the positions of the respective connecting parts. Consequently, the entire shapes of the respective first coil parts and the second coil parts can be designed to be the exact same shape, which makes it possible to reduce the number of types of coil part structuring the coil, saving labor and time for preparing many types of conductor patterns like the conventional type.
The multilayer coil component may include a plurality of coil parts each structuring a part of the coil, extending in a layer structuring the laminated structure, and having a pair of ends, each of the pair of ends having shapes same as the shapes of the pair of ends of the first coil part and being located at positions same as the positions of the pair of ends of the first coil part when viewed from the laminated direction, and a plurality of connecting parts alternately aligned with the plurality of the coil parts, each of the plurality of connecting parts being located at a position same as a position of the connecting part when viewed from the laminated direction and having a shape same as a shape of the connecting part. Each of the plurality of connecting parts is connected only to the second end of the pair of ends of a corresponding one of the plurality of coil parts positioned on the upper side in the laminated direction, and is connected only to the first end of the pair of ends of a corresponding one of the plurality of coil parts positioned on the lower side in the laminated direction. In this case, a coil can be structured in which the plurality of coil parts and the plurality of connecting parts are alternately aligned without misaligning the positions of the respective plurality of connecting parts. This makes it possible to design the entire shapes of the respective coil parts to be the exact same shape, reducing the number of types of the coil parts.
Note that at least one of the first end and the second end may have an end face forming a stepped portion. The insulating body may be formed of a magnetic material. The multilayer coil component may include a low magnetic permeability layer in a layer same as a layer of the connecting part.
Hereinafter, an embodiment of the disclosure will be described with reference to the accompanying drawings. Note that the same reference numerals are used for the same elements or elements having the same functions, and the overlapped description will be omitted.
First, the entire structure of a multilayer coil component 1 according to an embodiment of the disclosure will be described with reference to
As illustrated in
For convenience of description, XYZ coordinates are set as illustrated in the drawings. That is, a laminated direction of the multilayer coil component 1 is set as Z direction, an opposing direction of the end faces 10a, 10b on which the respective external terminal electrodes are provided is set as X direction, and a direction perpendicular to Z direction and X direction is set as Y direction.
The insulating body 10 is formed of a magnetic material, and can be formed of a ferrite (for example, Ni—Cu—Zn system ferrite, Ni—Cu—Zn—Mg system ferrite, Cu—Zn system ferrite), a metal magnetic material (Fe, Fe—Si, Fe—Si—Cr, Fe—Si—Al alloy, etc.), or a composite material of a metal and a ferrite. The upper most layer L1 and the lower most layer L20, which are covering layers, among the layers L1 to L20 structuring the multilayer coil component 1 are totally formed of a magnetic material. The other layers is also formed of a magnetic layer except a part where the coil 20 is formed and parts where low magnetic permeability layers 29 to be described below are formed.
The coil 20 is formed of a plurality of laminated metal layers. The material of the metal layers is not specifically limited and includes Ag, Cu, Au, Al, Pd, Pd/Ag alloy, etc. A Ti compound, a Zr compound, a Si compound, etc. may be added to the metal layers. Such metal layers can be formed by a printing method or a thin film growing method. As shown in
As shown in
Herein, the coil part 22 has an approximate annular shape having a divided portion 25 as its portion when viewed from the laminated direction. The coil part 22 may have a C character shape as shown in
In this regard, a position of the divided portion 25 in the upper coil layer 23 and a position of the divided portion 25 in the lower coil layer 24 are misaligned in the opposing direction of the first end 22a and the second end 22b (that is, X direction), forming a stepped portion 26 on each of end faces of the ends 22a, 22b. More specifically, in the first end 22a, the upper coil layer 23 is extended on the side of the divided portion 25 more than the lower coil layer 24 to form the stepped portion 26. In contrast, in the second end 22b, the lower coil layer 24 is extended on the side of the divided portion 25 more than the upper coil layer 23 to form the stepped portion 26.
The connecting part 28 is arranged at the position corresponding to the position of the divided portion 25 of the coil part 22, and has a rectangular shape extending along the opposing direction of the pair of ends 22a, 22b (that is, along the shape of the divided portion 25). The connecting part 28 connects the upper and lower coil parts 22 adjacent vertically to each other in the laminated direction. That is, the connecting part 28 is arranged in an annular coil forming area when viewed from the laminated direction, ensuring a sufficient inner diameter of the coil.
Each of the layers L3, L6, L9, L12, L15, L18 each including the connecting part 28 includes the low magnetic permeability layer 29 formed of a material having a low magnetic permeability (for example, non-magnetic material) in addition to the connecting part 28. More specifically, the low magnetic permeability layer 29 having a C character shape like the coil part 22 is formed in some layers (L3, L9, L15) including the connecting part 28, and the low magnetic permeability layer 29 is formed in the entire residual area excluding the connecting part 28 in other layers (L6, L12, L18) including the connecting part 28. The low magnetic permeability layers 29 form a magnetic gap, improving DC bias characteristics.
Next, a positional relationship between the coil part and the connecting part will be described in more detail with reference to
As illustrated in
The a point at the upper end position of the first end 22a is located on the connecting part 28 on the upper side, and the first end 22a is connected to the connecting part 28 on the upper side. The b point at the lower end position of the first end 22a is located at a retreated position with respect to the connecting part 28 on the lower side, and the first end 22a is not connected to the connecting part 28 on the lower side.
The c point at the upper end position of the second end 22b is located at a retreated position with respect to the connecting part 28 on the upper side, and the second end 22b is not connected with the connecting part 28 on the upper side. The d point at the lower end position of the second end 22b is located on the connecting part 28 on the lower side, and the second end 22b is connected to the connecting part 28 on the lower side.
Note that the length D of the connecting part 28 in the opposing direction is designed to be longer than the separation distance D1 between the a point at the upper end position of the first end 22a and the d point at the lower end position of the second end 22b, and to be shorter than the separation distance D2 between the b point at the lower end position of the first end 22a and the c point at the upper end position of the second end 22b.
As shown in
Furthermore, as shown in
As described above, in the multilayer coil component 1, the coil parts 22 each having the pair of ends 22a, 22b having the same shapes, and the connecting parts 28 each having the same shape are alternately aligned in the laminated direction, and any of the coil parts 22 and the connecting parts 28 has the same positional relationship. That is, each connecting part 28 connects the coil parts 22 adjacent vertically to each other in the laminated direction by connecting the second end 22b of the first coil part 22A on the upper side in the laminated direction, and the first end 22a of the second coil part 22B on the lower side in the laminated direction. Such a connection structures the coil 20 wound around along the laminated direction that allows current to flow in the coil parts 22 adjacent vertically to each other in a same circumferential direction.
As described above, in the multilayer coil component 1, even when the pair of ends 22a, 22b of each of the first coil part 22A and the second coil part 22B are located at the same positions when viewed from the laminated direction and have the same shapes, the connecting part 28 is connected only to the second end 22b of the first coil part 22A on the upper side in the laminated direction, and is connected only to the first end 22a of the second coil part 22B on the lower side in the laminated direction. This makes it possible to form the coil 20 wound around along the laminated direction without misaligning the positions of the respective connecting parts 28 even when the connecting part 28 is further provided on the upper side of the first coil part 22A or on the lower side of the second coil part 22B.
Therefore, in the multilayer coil component 1, the entire shape of each of the plurality of coil parts 22 can be designed to be the exact same shape, which makes it possible to reduce the number of types of coil part 22, saving labor and time for preparing many types of conductor patterns like the conventional type.
Furthermore, in the multilayer coil component 1, when viewed from the laminated direction, the connecting part 28 is arranged in the coil formation area to ensure a large inner diameter of the coil, making it possible to achieve high coil characteristics (for example, inductance or Q-value).
Furthermore, in the multilayer coil component 1, the coil parts 22 adjacent vertically to each other are not overlapped to each other in the connecting part 28, suppressing increase of the thickness of the connecting part 28. This also suppresses occurrence of large inner stress around the connecting part 28.
One method of manufacturing the above multilayer coil component 1 using, for example, a printing method is repeating printing from the lower most layer L20 to laminate layers one by one. In this case, the cross sections of the coil part 22, etc. probably have a gently curved outline different from the angular outline as illustrated in
Alternatively, it is also possible that a plurality of layers (for example, three layers of L3 to 5) is formed as one unit, and a plurality of the units is overlapped to manufacture the multilayer coil component 1. In this case, it is possible to efficiently manufacture the multilayer coil component 1 as compared with the method of laminating layers one by one by a printing method.
Note that the multilayer coil component is not limited to the above embodiment, and can be modified in various manners.
For example, the planer shape of the coil part may be a circle annular shape, an ellipsoidal annular shape, etc. other than a rectangular annular shape. Furthermore, each coil part does not necessarily need to be the exact same shape as the entire shape as long as at least the shapes of the pair of ends are same shapes. Furthermore, it is not necessary that the coil part forms one turn, and a coil part forming one half turn or one quarter turn may be employed. Furthermore, the coil part does not necessarily need to be two layer structure, and single layer structure or multilayer structure of not less than three layers may be employed. The number of the laminated layers of the multilayer coil component can be increased or reduced in any manner as needed.
It is not necessary to form the stepped portion on the end face of each of ends of the coil part, and the end face may be a slope face sloped in the laminated direction, for example.
Furthermore, it is not necessary that the connecting part has a shape extending in one direction when viewed from the laminated direction, and may have a bend shape or a curved shape. For example, when the shape of the coil part in plan view is a polygonal annular shape, using a connecting part having a bent shape or a curved shape makes it possible to connect upper and lower coil parts at the position corresponding to a corner of the coil part.
Number | Date | Country | Kind |
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2015-146575 | Jul 2015 | JP | national |
Number | Name | Date | Kind |
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20090051476 | Tada | Feb 2009 | A1 |
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20110128109 | Tada et al. | Jun 2011 | A1 |
20130234285 | Hijioka | Sep 2013 | A1 |
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20150014042 | Noguchi | Jan 2015 | A1 |
Number | Date | Country |
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101390176 | Mar 2009 | CN |
2010-153617 | Jul 2010 | JP |
2010153617 | Aug 2010 | JP |
2010-192715 | Sep 2010 | JP |
2015-018852 | Jan 2015 | JP |
2008-0091778 | Oct 2008 | KR |
2013-0019195 | Feb 2013 | KR |
20130019195 | Feb 2013 | KR |
Number | Date | Country | |
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20170025219 A1 | Jan 2017 | US |