BACKGROUND OF THE INVENTION

I. Field of the Invention

The present invention relates to an electronic device, and in particular, to an inductor.

II. Description of Related Art

Conventional inductors cannot prevent the proximity effect caused by an external magnetic field when there is a current passing through it at an operating frequency, especially when the conventional inductor is used in a receiver of a wireless charger. Finding a way to decrease the proximity effect of the inductor becomes a crucial issue, especially when the inductor is used in a wireless charger.

Therefore, a solution is needed to decrease the proximity effect of the inductor, especially when the inductor is used in a wireless charger.

SUMMARY OF THE INVENTION

One objective of the present invention is to add a shielding layer comprising a conductive and magnetic material to encapsulate the bare metal wire of a coil so as to shield the coil from the external magnetic field and make the resistance or ACR (alternating current resistance) of the coil lower.

One objective of the present invention is to form two electrodes of an inductor so that the two electrodes of the inductor can be placed side by side for electrically connecting with an external circuit.

One objective of the present invention is to dispose a plurality of separated graphene sheets over the bottom surface of an inductor so as to reduce eddy currents and the power loss of the inductor.

In one embodiment of the present invention, an electronic device is disclosed, wherein the electronic device comprises: a coil, wherein the coil comprises a plurality of winding turns of a bare metal wire; and a shielding layer comprising a first conductive and magnetic material to encapsulate each of the plurality of winding turns of the coil.

In one embodiment, the first conductive and magnetic material comprises nickel (Ni).

In one embodiment, the electronic device is an inductor.

In one embodiment, the electronic device is a receiver of a wireless charger.

In one embodiment, the coil is formed by removing unwanted portions of a metal plate.

In one embodiment, the metal plate comprises copper.

In one embodiment, the metal plate is a copper plate.

In one embodiment, the shape of a cross-section of each winding turn in the thickness direction of the coil is rectangular, and the total thickness of the coil and the shielding layer is about 0.1 mm, or in a range: 0.08 mm-0.12 mm.

In one embodiment, a second magnetic and adhesive material encapsulates the shielding layer and the coil. In one embodiment, the second magnetic and adhesive material is a magnetic glue.

In one embodiment, an encapsulating layer or a molding body encapsulates the shielding layer and the coil and extends into the hollow space of the coil.

In one embodiment, the encapsulating layer or the molding body comprises a magnetic material.

In one embodiment, the encapsulating layer or the molding body comprises ferrite.

In one embodiment, a plurality of separated graphene sheets are disposed over the bottom surface of the encapsulating layer. In one embodiment, the plurality of separated graphene sheets are entirely made of graphite.

In one embodiment, a vertical straight line passes the center of the coil and a gap between the plurality of separated graphene sheets.

In one embodiment, the first conductive and magnetic material is made of nickel (Ni).

In one embodiment, the inductor is used in a wireless charger, wherein the operating frequency of the inductor ranges from 100 kHz to 400 kHz.

In one embodiment, the thickness of the shielding layer made of nickel (Ni) is in a range of 1.5 um to 15 um.

In one embodiment, the thickness of the shielding layer made of nickel (Ni) is in a range of 5 um to 15 um.

In one embodiment, the thickness of the shielding layer made of nickel (Ni) is in a range of 10 um to 14 um.

In one embodiment, the thickness of a winding turn of the coil is in a range of 50 um to 200 um, wherein the thickness of the shielding layer is in a range of 1.5 um to 20 um.

In one embodiment, the thickness of a winding turn of the coil is in a range of 50 um to 100 um, wherein the thickness of the shielding layer is in a range of 1.5 um to 15 um.

In one embodiment, the thickness of a winding turn of the coil is in a range of 60 um to 80 um, wherein the thickness of the shielding layer is in a range of 1.5 um to 10 um.

In one embodiment, the inductor is used in a wireless charger, wherein the operating frequency of the inductor is about 6.78 MHz.

In one embodiment, the inductor comprises a first electrode and a second electrode, wherein the first electrode is electrically connected to the outermost terminal part of the coil pattern, and the second electrode is electrically connected to the innermost terminal part of the coil pattern via a conductive part disposed across the plurality of winding turns.

In one embodiment, the conductive part comprises a terminal part of the coil.

In one embodiment, the conductive part comprises a metal lead.

In one embodiment, the conductive part comprises a lead frame that is encapsulated by tin.

In one embodiment, for each two adjacent winding turns of the plurality of winding turns, the width of the inner winding turn is less than that of the outer winding turn.

In one embodiment, the plurality of winding turns are nine winding turns, wherein the width of each of the innermost two winding turns and the outermost winding turn is half of the width of each of the other winding turns.

In one embodiment of the present invention, an electronic device is disclosed, wherein the electronic device comprises: a coil, formed by removing unwanted portions of a metal plate, wherein the coil comprises a plurality of winding turns; and a first electrode and a second electrode, wherein the first electrode is electrically connected to the outermost terminal part of the coil, and the second electrode is electrically connected to the innermost terminal part of the coil via a conductive part disposed across the plurality of winding turns, so that the first electrode and the second electrode can be placed side by side at the outmost side of the coil for electrically connecting with an external circuit.

In one embodiment of the present invention, an electronic device is disclosed, wherein the electronic device comprises: a coil, wherein the coil comprises a plurality of winding turns; and a plurality of separated graphene sheets, disposed over the bottom surface of the coil for reducing eddy currents, wherein a vertical straight line passes the center of the coil and a gap between the plurality of separated graphene sheets.

In one embodiment of the present invention, a method for forming an electronic device comprising a coil is disclosed, wherein the method comprises: providing a coil comprising a plurality of winding turns of a bare metal wire; and using a first conductive and magnetic material to encapsulate the coil.

In one embodiment of the present invention, a method for forming an electronic device is disclosed, wherein the method comprises: removing unwanted portions of a metal plate to form a coil comprising a plurality of winding turns of the coil; forming a shielding layer comprising a first conductive and magnetic material to encapsulate each of the plurality of winding turns of the coil; and using a second magnetic and adhesive material to encapsulate the plurality of winding turns of the coil and the shielding layer.

In one embodiment of the present invention, a method for forming an electronic device is disclosed, wherein the method comprises: removing unwanted portions of a metal plate to form a coil comprising a plurality of winding turns; and using a first conductive and magnetic material to encapsulate 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.

