This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 097133840 filed in Taiwan, Republic of China on Sep. 4, 2008, the entire contents of which are hereby incorporated by reference.
1. Field of Invention
The present invention relates to a magnetic element and, in particular, to a filter that is capable of eliminating the common-mode noise.
2. Related Art
The applications of the present electronic circuits have been widely spread. These kinds of electronic circuits are usually operated at high frequency, which can easily generate the electro magnetic interference (EMI). The high frequency noise can be transmitted by electromagnetic radiation or power line conduction so as to interfere the normal operation of other electronic apparatuses. The conduction EMI can be divided, according to the noise current paths, to the differential-mode (DM) noise and the common-mode (CM) noise.
In order to efficiently eliminate the EMI, the filter, which is corresponding to the type of the noise to be eliminated, is usually configured in the electronic device. For example, to eliminate the CM noise, the electronic device can be configured with a filter for eliminating the CM noise. The filter can be formed by stacking a plurality of metal coil layers and independent insulating layers. However, the properties of the filter, such as the bandwidth or the inductance value, are closely related to the layout design of the metal coil layers. The bandwidth or inductance value of the conventional filter is restricted due to the space limitation.
In view of the foregoing, the present invention is to provide a magnetic element that has larger bandwidth and can efficiently eliminate the noise.
To achieve the above, the present invention discloses a magnetic element including a pair of coil sets and a package body. Each of the coil sets includes a first coil, a second coil and at least one conductive column. The first coil has a plurality of first metallic lines, and the second coil has a plurality of second metallic lines. The conductive column is electrically connected between the first and second coils. The package body encloses the pair of coil sets therein.
The first and second coils have a spiral distribution in a projecting direction. The first or second metallic lines are aligned on the same plane in another projecting direction.
Preferably, the first metallic lines and a part of the second metallic lines are overlapped in the projecting direction. Alternatively, the first and second metallic lines are totally overlapped in the projecting direction. Probably, the first and second metallic lines are not overlapped in the projecting direction. In addition, the first and second metallic lines are partially overlapped in the projecting direction.
Preferably, the thicknesses of the first and second coils range between 9 to 11 μm. In addition, an interval between the metallic lines ranges between 30 to 60 μm, and the width of the metallic lines ranges between 10 to 15 μm.
In addition, the package body further includes a first magnetic substrate, a second magnetic substrate and an intermediate layer. The second magnetic substrate is disposed opposite to the first magnetic substrate. The intermediate layer is disposed between the first and second magnetic substrates, and the coil sets are disposed in the intermediate layer.
The intermediate layer includes at least one dielectric layer or insulating layer and has at least one through hole. A magnetic material is filled in the through hole or a side area of the magnetic element. The magnetic material includes a magnetic power and a resin.
Alternatively, the intermediate layer can include a single or multiple dielectric layers or insulating layers. The thickness of each of the dielectric layers or insulating layers ranges between 4 to 20 μm.
The pair of coil sets and the first or second magnetic substrates are separated by an insulating layer or a dielectric layer.
The magnetic element further includes a first electrode electrically connected to one of the first metallic lines and a second electrode electrically connected to one of the second metallic lines. One end of the first electrode connected to the first metallic line and one end of the second electrode connected to the second metallic line are extended to opposite or the same direction. The second electrode is electrically connected to one of the second metallic lines disposed at the inner side of the second coil.
In addition, the magnetic element further includes a plurality of external electrodes electrically connected to the first and second electrodes. The external electrode is formed by sputtering and electroplating.
The pair of coil sets are separated by an insulating layer or a dielectric layer.
Preferably, the magnetic element is a filter for eliminating the common-mode (CM) noise.
To achieve the above, the present invention also discloses a magnetic element, which includes a first coil, a second coil and at least one conductive column. The first coil has a plurality of first metallic lines, and the second coil has a plurality of second metallic lines. The conductive column is connected between the first and second coils. The first and second coils have a spiral distribution. The first and second metallic lines are partially overlapped, totally overlapped or not overlapped in a projecting direction.
The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
Please refer to
As shown in
The connections between the first metallic lines L11 to L18 and the second metallic lines L21 to L28 will be described hereinbelow. Referring to
As shown in
As shown in
The magnetic element further includes a package body for enclosing the coil sets therein. The package body includes a first magnetic substrate, a second magnetic substrate and an intermediate layer disposed between the first and second magnetic substrates. The pair of coil sets are disposed in the intermediate layer. The intermediate layer includes a single or multiple dielectric layers or insulating layers 103 for separating the pair of coil sets. The coil sets and the first or second magnetic substrates are separated by the dielectric layer 103. The thickness of each dielectric layer or insulating layer ranges between 4 to 20 μm, and the thickness of the first and second coils ranges between 9 to 11 μm, respectively. The interval between the metallic lines ranges between 30 to 60 μm, and the width of each of the metallic lines ranges between 10 to 15 μm. Of course, the above-mentioned values can be adjusted according to the actual need. The conductive column can be formed by filling a conductive material in a conductive hole of the dielectric layer.
In addition, the magnetic element further includes a magnetic material filled in a through hole H of the dielectric layer 303 and at least a side area 314 of the magnetic element as shown in
The first electrode 312 is electrically connected to the second metallic line L61, and the second electrode 313 is electrically connected to the second metallic line L66. One end of the first electrode 312 connected to the second metallic line and one end of the second electrode 313 connected to the second metallic line are extended to opposite directions.
In summary, the magnetic element of the present invention has the first and second coils, which have a spiral distribution. In addition, the first and second coils are connected by the conductive column, so that the layouts of the first and second coils can be totally overlapped, partially overlapped or not overlapped in the vertical projecting direction. Thus, the magnetic element of the present invention can be sufficiently minimized and have larger bandwidth or inductance value. In addition, the magnetic element of the present invention can be a filter for eliminating the CM noise.
Although the present invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the present invention.
Number | Date | Country | Kind |
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097133840 | Sep 2008 | TW | national |