Patent Grant
11367562
The present invention relates to a magnetic device, and in particular, to a magnetic device having a coil made by an insulated conductive wire.
Conventional electronic components, such as inductors and chokes, are often prepared by high-pressure molding of a coil and a magnetic powder so as to form a magnetic body encapsulating the coil. In the high-pressure molding process, particles of the magnetic powder penetrate into the insulation layer of the conductive wire of the coil, rendering the coil unable to sustain higher pressure or interlayer short circuits. However, if a lower pressure is used during the molding process, the density of the magnetic body will be reduced and the inductance of the inductor or choke will drop off as well. If the thickness of the insulating layer of the coil is increased, it will be difficult to wind the conductive wire like a coil and the size of the coil size will also be too large, resulting in a lowered inductance.
Therefore, a better solution is needed to resolve the above-mentioned issues.
One objective of the present invention is to add a coating layer to encapsulate a coil to prevent particles of at least one magnetic powder from penetrating into the insulating layer of the conductive wire of the coil during a molding process so as to avoid short circuits of the coil.
One objective of the present invention is to add a coating layer to encapsulate a coil for preventing the self-adhesive layer flowing out during a molding process to form a molding body encapsulating the coil.
One objective of the present invention is to add a coating layer to encapsulate a coil to increase the degree of the insulation between the coil and the magnetic body so as to allow the coated coil to sustain higher voltages.
The present invention provides a coating layer to encapsulate the insulated conductive wire of the coil disposed in a magnetic body comprising at least one magnetic powder to prevent particles of the at least one magnetic powder from damaging the insulated insulating layer of the insulated conductive wire of the coil so as to avoid unwanted short circuits between different portions of the coil.
In one embodiment of the present invention, a magnetic device is disclosed, wherein the magnetic device comprises: a coil, comprising a plurality of winding turns of an insulated conductive wire, wherein the insulated conductive wire comprises a conductive metal wire and at least one first insulating layer encapsulating the conductive metal wire, wherein at least two different portions of the coil form a first space therebetween; a coating layer, comprising an insulating material to encapsulate said at least two different portions of the coil and fills into said first space; and a magnetic body, wherein the magnetic body comprises at least one magnetic powder and an adhesive material to mix particles of the at least one magnetic powder, wherein the magnetic body encapsulates the plurality of winding turns of the insulated conductive wire and the coating layer.
In one embodiment, the magnetic body has a unitary body that encapsulates the plurality of winding turns of the insulated conductive wire and the coating layer and extends into the hollow space of the coil.
In one embodiment, two different portions of adjacent outer winding turns of the insulated conductive wire form the first space therebetween, wherein the coating layer encapsulates said two different portions of adjacent outer winding turns of the insulated conductive and extends into said first space.
In one embodiment, a portion of a winding turn of the insulated conductive wire and a portion of a terminal part of the insulated conductive wire forms the first space therebetween, wherein the coating layer encapsulates said portion of the winding turn of the insulated conductive wire and said first portion of the terminal part of the insulated conductive wire and extends into said first space.
In one embodiment, the entire outer surface of the plurality of winding turns of an insulated conductive wire is encapsulated by the coating layer.
In one embodiment, the magnetic device is an inductor.
In one embodiment, the at least one first insulating layer comprises only one insulating layer.
In one embodiment, the at least one first insulating layer comprises two insulating layers, wherein said two insulating layers are made of different insulating materials.
In one embodiment, the coating layer comprises a polymer material.
In one embodiment, the coating layer comprises a resin.
In one embodiment, the coating layer comprises an organic material.
In one embodiment, the magnetic body comprises only one magnetic powder.
In one embodiment, the magnetic body comprises a first magnetic powder and a second magnetic powder, wherein the first magnetic powder and the second magnetic powder are mixed with the adhesive material.
In one embodiment of the present invention, a method for forming a magnetic device is disclosed, wherein the method comprises: providing a coil comprising a plurality of winding turns of an insulated conductive wire, wherein the insulated conductive wire comprises a conductive metal wire and at least one first insulating layer encapsulating the conductive metal wire, wherein at least two different portions of the insulated conductive wire form a first space therebetween; forming a coating layer comprising an insulating material to encapsulate said at least two different portions of the insulated conductive wire, said insulating material being filled into said first space; and forming a magnetic body to encapsulate the plurality of winding turns of the insulated conductive wire and the coating layer, wherein the magnetic body comprises at least one magnetic powder and an adhesive material to mix particles of the at least one magnetic powder, so as to prevent particles of the magnetic powder from damaging the corresponding portions of the at least one first insulating layer of the at least two different portions of the coil.
In order to make the aforementioned and other features and advantages of the present invention more comprehensible, several embodiments accompanied with figures are described in detail below.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
For the following description, the terms D10, D50 and D90 are used for describing the particle size distribution of magnetic powders. D10 means 10% of the total number of the particles is less than the D10, D50 means 50% of the total number of the particles is less than D50 and D90 means 90% of the total number of the particles is less than D90.
As shown in
In one embodiment, the insulated conductive wire has only one insulating layer: the first insulating layer 101b.
In one embodiment, the insulated conductive wire has only two insulating layers: the first insulating layer 101b and a second insulating layer 101c.
In one embodiment, the second insulating layer 101c can be a self-adhesive layer, wherein the coating layer coated 103 on the self-adhesive layer can prevent the self-adhesive layer flowing out during a molding process. Furthermore, the coating layer 103 coated on the self-adhesive layer can further electrically isolate the coil from particles of the at least one magnetic powder to avoid a short circuit caused by particles of the at least one magnetic powder. In one embodiment, the insulated conductive wire can be an enameled wire, wherein the enameled wire can have a circular shape. In one embodiment, the conductive metal wire of the enameled wire comprises copper.
In one embodiment, as shown in
In one embodiment, the entire outer surface and the entire inner surface of the plurality of winding turns of the coil 201 are encapsulated by the coating layer 103.
In one embodiment, a portion of a winding turn of the insulated conductive wire and a lead that is electrically connected to a terminal part of the insulated conductive wire of the coil forms a second space therebetween, wherein the coating layer encapsulates said portion of a winding turn of the insulated conductive wire and at least one portion of the lead and extends into said second space.
In one embodiment, the insulated conductive wire has only one insulating layer: the first insulating layer 101b.
Please note that the coating layer 103 can encapsulate just the portions of the coil that are easily shorted by the particles of the at least one magnetic powder. That is, it is not necessary to coat the entire outer surface of the coil 201, as shown in
In one embodiment, the at least one first insulating layer comprises two insulating layers, wherein said two insulating layers are made of different insulating materials.
In one embodiment, the magnetic device is an inductor.
In one embodiment, the coating layer comprises a polymer material.
In one embodiment, the coating layer comprises a resin.
In one embodiment, the coating layer comprises an organic material.
In one embodiment, the magnetic body comprises a first magnetic powder and a second magnetic powder, wherein the first magnetic powder and the second magnetic powder are mixed with an adhesive material.
In one embodiment, wherein the D50 of the first magnetic powder is in the range of 8 to 36 um while the D50 of the second magnetic powder is in the range of 1.0 to 10 um, the D10 of the first magnetic powder is in the range of 3 to 20 um while the D10 of the second magnetic powder is in the range of 0.5 to 6 um, and the D90 of the first magnetic powder is in the range of 20 to 60 um while the D90 of the second magnetic powder is in the range of 2 to 12 um.
In one embodiment, the magnetic body comprises a first magnetic powder, wherein D50 of the first magnetic powder is in the range of 17 to 36 um, the D10 of the first magnetic powder is in the range of 8 to 26 um, and the D90 of the first magnetic powder is in the range of 30 to 52.
In one embodiment, the magnetic body comprises a first magnetic powder, wherein D50 of the first magnetic powder is in the range of 8 to 16 um, the D10 of the first magnetic powder is in the range of 3 to 6 um, and the D90 of the first magnetic powder is in the range of 18 to 30.
In one embodiment, the magnetic body 104 encapsulates the plurality of winding turns of the insulated conductive wire of the coil 201 and extends into the hollow space of the coil 201.
In one embodiment, the coating layer 103 extends into a hollow space of the coil 201 to encapsulate the inner surface of the coil.
In one embodiment, a lead 140 is disposed on the magnetic body 104 and electrically connected to the coil 201.
As shown in
In one embodiment, two adjacent winding turns of the insulated conductive forms the first space 102 therebetween, wherein the first insulating material of the coating layer 103 is filled into the first space 102 for preventing at least one particle of the at least one magnetic powder from being disposed in said first space, since the at least one particle of the at least one magnetic powder may penetrate into the at least one first insulating layer and cause a short circuit between said two different portions of the insulated conductive wire.
There are many ways to encapsulate the at least two different portions of the insulated conductive wire with the second insulating material, for example, by dipping an insulating material on the wound insulated wire or spraying an insulating material on the wound insulated wire or soaking the wound insulated wire in an insulating material or dispensing glue on the wound insulated wire or pouring glue on the wound insulated wire so that an outer surface of the coil can be encapsulated by the insulating material for preventing particles of the magnetic powder from penetrating the at least one insulating layer of the wound insulated wire.
The present invention has many advantages: (1) the coating layer can prevent particles of the magnetic powder that are used to form a magnetic body of the magnetic device from penetrating into the insulating layer of the insulated conductive wire of the coil so that the coil can sustain higher pressure without producing short circuits of the coil when the magnetic powder is pressed to form the magnetic body; (2) the coating layer can prevent the flow of the self-adhesive layer of the insulated conductive during the molding process to form the magnetic body; (3) increase the degree of insulation between the coil and the magnetic powder; (4) enabling the coated coil to sustain higher voltage.
Although the present invention has been described with reference to the above embodiments, it will be apparent to one of ordinary skill in the art that modifications to the described embodiment may be made without departing from the spirit of the invention. Accordingly, the scope of the invention will be defined by the attached claims, not by the above-detailed descriptions.
| Number | Name | Date | Kind |
|---|---|---|---|
| 20020067232 | Oshima | Jun 2002 | A1 |
| 20160133377 | Takagi | May 2016 | A1 |
| 20180204657 | Shinkai | Jul 2018 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20200251277 A1 | Aug 2020 | US |
