Patent Application
20160276090
This application claims the benefit under 35 USC 119(a) of Korean Patent Application No. 10-2015-0037443, filed with the Korean Intellectual Property Office on Mar. 18, 2015, the disclosure of which is incorporated herein by reference in its entirety.
1. Field
The following description relates to a coil component and a method of manufacturing the coil component having a high magnetic permeability.
2. Description of Related Art
With the advancement in technology, electronic devices, such as mobile phones, home electronic appliances, personal computers, personal digital assistants (PDA) and liquid crystal displays (LCD), have transformed from being analog to being digital and have become increasingly faster due to the increased amount of processed data.
Accordingly, high-speed interfaces, such as universal serial bus (USB) 2.0, USB 3.0 and a high-definition multimedia interface (HDMI), have been widely used in various digital devices, including personal computers and high-definition digital television.
Unlike the single-end transmission systems, which have been conventionally used for a long time, these high-speed interfaces adopt a differential signal system transmitting differential signals (differential mode signals) using a pair of signal lines. However, as the electronic devices are faster in processing time, these devices are more sensitive to stimulation from an external environment, such as noise. As a result, signal distortions often occur in the electronic devices. The signal distortions are normally produced by a high-frequency noise.
A filter is often installed in the electronic devices in order to remove such noise. The filter is popularly used as a coil component to remove a common mode noise in a high-speed differential signal line as a common mode filter (CMF). As the common mode noise is a noise generated in a differential signal line, the common mode filter removes the common mode noise that cannot be removed using a conventional filter.
Meanwhile, as today's electronic products have become increasingly faster, multi-functional and higher-performance oriented, a higher magnetic permeability is required for the coil components used in these electronic products. One of the most universal measures to satisfy the higher permeability requirement is to increase a number of turns of coils by providing a finer space between the coils.
However, increasing the number of coil turns is not easily feasible when manufacturing ultra-small coil components, such as 1005 (1.0 mm×0.5 mm×0.5 mm), 0603 (0.6 mm×0.3 mm×0.3 mm) and 0403 (0.4 mm×0.3 mm×0.3 mm), and complicates the manufacturing process, thereby increasing the manufacturing costs.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
In accordance with an embodiment, there is a coil component, including: an insulation layer including a coil conductor; and a magnetic-resin composite layer disposed on the insulation layer, wherein the magnetic-resin composite layer may include a magnetic core.
The magnetic core may penetrate a middle portion of the magnetic-core composite layer.
The magnetic core may be a sintered ferrite.
The magnetic core may be extended toward the insulation layer and a portion thereof is sunk in the insulation layer.
The magnetic core may penetrate the insulation layer, and the coil conductor is wound about the magnetic core.
The coil component may also include external electrodes disposed at upper outer corners of the insulation layer, wherein the magnetic-resin composite layer is formed in between the external electrodes.
The coil component may also include a magnetic substrate disposed below the insulation layer.
The coil conductor may include a first coil and a second coil electromagnetically coupled to each other.
In accordance with an embodiment, there is provided a method of manufacturing a coil component, including: forming an insulation layer including a coil conductor; disposing a magnetic core at an upper middle portion of the insulation layer; and forming a magnetic-resin composite layer above the insulation layer.
Prior to the disposing of the magnetic core, a groove is formed at a portion of the insulation layer, and further including: inserting and disposing the magnetic core in the groove.
The groove may be formed to penetrate the insulation layer.
The magnetic-resin composite layer may be formed by coating a magnetic-resin paste or laminating a magnetic-resin film.
The method may also include forming external electrodes at upper outer corners of the insulation layer, prior to the forming of the magnetic-resin composite layer.
The method may also include prior to the forming of the insulation layer, obtaining a magnetic substrate, wherein, the insulation layer including the coil conductor is formed above the magnetic substrate.
In accordance with another embodiment, there is provided a method to form a coil component, including: preparing a substrate by sintering magnetic powder; laminating and forming an insulation layer on the substrate, wherein the insulation layer may include a coil conductor; forming a groove at an upper portion of the insulation layer; inserting the magnetic core into the groove; forming external electrodes at outer corners above the insulation layer, wherein the external terminals comprise a same height as a height of the magnetic core and are positioned near corners of the insulation layer; and forming a magnetic-resin composite layer above the insulation layer.
The method may also include coating the insulation material on an upper surface of the substrate in order to mitigate a surface roughness of the substrate, and forming one layer of the coil conductor on the coated insulation layer.
The magnetic core may penetrate an upper center portion of the magnetic-resin composite layer.
The magnetic core may penetrate an upper off-center portion of the magnetic-resin composite layer.
The magnetic core may be solid.
The magnetic core may extend from an upper surface of the magnetic-resin composite layer toward the insulation layer, where a portion of the magnetic core is sunk in the insulation layer. Other features and aspects will be apparent from the following detailed description, the drawings, and the claims.
Throughout the drawings and the detailed description, the same reference numerals refer to the same elements. The drawings may not be to scale, and the relative size, proportions, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience.
The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be apparent to one of ordinary skill in the art. The sequences of operations described herein are merely examples, and are not limited to those set forth herein, but may be changed as will be apparent to one of ordinary skill in the art, with the exception of operations necessarily occurring in a certain order. Also, descriptions of functions and constructions that are well known to one of ordinary skill in the art may be omitted for increased clarity and conciseness.
The features described herein may be embodied in different forms, and are not to be construed as being limited to the examples described herein. Rather, the examples described herein have been provided so that this disclosure will be thorough and complete, and will convey the full scope of the disclosure to one of ordinary skill in the art. The terms used in the description are intended to describe certain embodiments. Unless clearly used otherwise, expressions in a singular form include the meaning of a plural form. Any characteristic, number, step, operation, element, part or combinations thereof used in the present description shall not be construed to preclude any presence or possibility of one or more other characteristics, numbers, steps, operations, elements, parts or combinations thereof.
Words describing relative spatial relationships, such as “below”, “beneath”, “under”, “lower”, “bottom”, “above”, “over”, “upper”, “top”, “left”, and “right”, may be used to conveniently describe spatial relationships of one device or elements with other devices or elements. Such words are to be interpreted as encompassing a device oriented as illustrated in the drawings, and in other orientations in use or operation. For example, an example in which a device includes a second layer disposed above a first layer based on the orientation of the device illustrated in the drawings also encompasses the device when the device is flipped upside down in use or operation.
Hereinafter, certain embodiments are described in detail with reference to the accompanying drawings.
Referring to
The insulation layer 110 is formed to envelop and embed the coil conductor 111 therein so as to provide insulation between the coil conductor 111 and another coil conductor 111 and protect the coil conductor 111 from an external condition such as moisture or heat. Accordingly, the insulation layer 110 is made of a material having good heat-resisting and moisture-resisting properties as well as an insulating property, for example, epoxy resin, phenol resin, urethane resin, silicon resin or polyimide resin.
In an example, the insulation layer 110 is formed by forming a base layer to provide a base and a flatness and then successively laminating the coil conductor 111 and a build-up layer of the insulation layer 110 covering the coil conductor 111. However, as illustrated, a boundary between layers may be integrated unidentifiably during high-temperature, high-pressure laminating and firing processes.
The coil conductor 111, which is a coil pattern of metal wire formed on a plane in a spiral form, is made of at least one of highly electrically conductive metals including, but not limited to, silver (Ag), palladium (Pd), aluminum (Al), nickel (Ni), titanium (Ti), gold (Au), copper (Cu) and platinum (Pt).
The coil conductor 111 is formed in a multilayered structure, in which plural coil conductors are separated from one another at a predetermined distance on a same layer, and laminated repeatedly in a thickness direction. The coil conductors 111 on different layers are disposed to face opposite to each other in vertical directions to form a coil by making an interlayer connection through a via or other connecting structural element.
In an example, the coil conductor 111 is formed with a first coil and a second coil, which are electromagnetically coupled to each other and are each forming an individual coil. For instance, the first coil and the second coil are electromagnetically coupled to each other and are disposed above and below each other or are alternately disposed on a same layer. Accordingly, the coil component 100 operates as a common mode filter (CMF) in which the magnetic flux is reinforced when a current is applied to the first coil and the second coil in a same direction and in which the magnetic flux is canceled out. A differential mode impedance is decreased when the current is applied to the first coil and the second coil in opposite directions.
The insulation layer 110 is laminated with a magnetic substrate 130 disposed under the insulation layer 110. That is, the magnetic substrate 130 is a plate-type support having a high modulus.
Moreover, the magnetic substrate 130 becomes a moving path of magnetic flux generated around the coil conductor 111 when a current is applied. Accordingly, the magnetic substrate 130 is made of any magnetic material as long as a predetermined inductance is obtained, for example, a Ni-based ferrite material having Fe2O3 and NiO as main components, a Ni—Zn ferrite material having Fe2O3, NiO and ZnO as main components, or a Ni—Zn—Cu ferrite material having Fe2O3, NiO, ZnO and CuO as main components.
In order to better facilitate the flow of magnetic flux, a magnetic member may be further provided above the insulation layer 110. However, because pad types of external electrodes 112 are formed to be externally exposed and electrically connect to an external electrical element at outer corners above the insulation layer 110, it would be difficult to dispose a solid type of magnetic member. A fluid type of magnetic member, such as a magnetic-resin composite layer 120, is instead filled in an empty space among the external electrodes 112.
The magnetic-resin composite layer 120 is made of a polymer resin having magnetic powder contained therein as a filler. As a result, the magnetic-resin composite layer 120 has a high magnetic permeability depending on a content ratio and a size of the magnetic powder. Generally, the larger the magnetic powder, the higher the magnetic permeability. However, an excessive size of the magnetic powder inhibits the magnetic powder from flowing easily to a point of possibly lowering a filling rate and causing a void inside the magnetic-resin composite layer 120.
Accordingly, the coil component 100, in accordance with an embodiment, has a magnetic core 140 inserted in the magnetic-resin composite layer 120 to provide a high magnetic permeability without an occurrence of a defect such as the void. In one configuration, the magnetic core 140 is made of sintered ferrite that is manufactured by sintering magnetic powder, such as Ni-based ferrite, Ni—Zn ferrite or Ni—Zn—Cu ferrite, and is disposed or positioned to penetrate a center of the magnetic-resin composite layer 120. In accordance with an alternative configuration, the magnetic core 140 is disposed or positioned to penetrate an off-center location of the magnetic-resin composite layer 120.
As such, in an embodiment in which the magnetic core 140 is provided as a solid, the magnetic permeability is prevented from falling, by inhibiting an increase of coercive force caused by domain wall pinning. Moreover, when a current is applied, magnetic flux generated around the coil conductor 111 passes through the magnetic-resin composite layer 120 and the magnetic substrate 130 at an upper portion and a lower portion of the coil conductor 111 and through the magnetic core 140 at a middle portion of the core conductor 111, thereby forming a closed magnetic circuit. As a result, a continuity of the magnetic flux is maintained to realize a high magnetic permeability.
As such, in the core component 100, in accordance with an embodiment, a high magnetic permeability is guaranteed by the magnetic core 140. As a result, it is possible to simplify a structural configuration of the coil component and manufacturing process thereof, compared to the conventional structure in which the magnetic permeability has been raised by increasing the number of coil turns. Accordingly, a yield is improved and the production costs are lowered. Moreover, with the configuration of, at least, the magnetic core 140, the magnetic-resin composite layer 120 is realized to have a high density and a high filling rate, by properly adjusting a size of the magnetic powder contained in the magnetic-resin composite layer 120.
Referring to
As the magnetic permeability increases in proportion to the size of the magnetic core 140, the more the portion of the magnetic core 140 sinks in the insulation layer 110, the more the coil property is improved. Accordingly, as shown in
Moreover, the above structure allows the coil component 100 to be manufactured easily, which will be described later in detail when a method of manufacturing a coil component is described.
As shown in
Then, as shown in
For instance, an insulation material is coated on an upper surface of the magnetic substrate 130 in order to mitigate a surface roughness of the magnetic substrate 130, and one layer of coil conductor 111 is formed on the coated insulation layer using a plating process, for example, the semi-additive process (SAP), the modified semi-additive process (MSAP) or the subtractive process. Afterwards, an insulation material is coated again to cover the coil conductor 111. The operations described above are repeated until the required number of layers of coil conductor 111 is reached. Then, by sintering the laminated insulation material and coil conductor 111, the insulation layer 110 having the coil conductor 111 installed therein is completed.
As shown in
Then, as illustrated in
Thereafter, as shown in
The external terminals 112 are formed with a same height as that of the magnetic core 140 using a common plating process. In one illustrative example, a total of four external electrodes 112, including a pair of external terminals connected to either end of a first coil of the coil conductor 111. The pair of the external terminals respectively function as input and output terminals of the first coil. Another pair of external terminals is connected to either end of a second coil and respectively function as input and output terminals of the second coil. Both pairs of external terminals are positioned near four corners of the insulation layer 110, in a clockwise or counterclockwise direction, from an upper left corner of the insulation layer 110.
Lastly, as shown in
The magnetic-resin composite layer 120 is formed by filling and drying a magnetic-resin paste, which is manufactured by impregnating polymer resin in a magnetic powder, in an empty space in between the external electrodes 112 and the magnetic core 140 or by laminating a magnetic-resin film, which is manufactured by semi-hardening the magnetic-resin paste to a film form, on the insulation layer 110.
While this disclosure includes specific examples, it will be apparent to one of ordinary skill in the art that various changes in form and details may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features or aspects in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques are performed in a different order, and/or if components in a described system, architecture, device, or circuit are combined in a different manner, and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2015-0037443 | Mar 2015 | KR | national |
