TWI742409B - Inductor and the method to make the same - Google Patents

Abstract

A coating layer is used to encapsulate winding turns of an insulated conductive wire of a coil that is encapsulated by a magnetic material containing magnetic particles so as to prevent the magnetic particles from damaging the insulated insulating layer of the insulated conductive wire of the coil when the magnetic material is pressed to form a magnetic body, thereby avoiding unwanted short circuits that are caused by the magnetic particles and damaged portions of the insulated conductive wire.

Description

Inductor and its manufacturing method

The present invention relates to a magnetic device, in particular to a magnetic device having a coil made of an insulated wire.

Conventional electronic components such as inductors and chokes are usually prepared by high-pressure molding of a coil made of an insulated wire and a magnetic powder to form a magnetic body covering the coil. During the high-pressure molding process, the particles of the magnetic powder may pierce the insulating layer of the insulated wire due to the molding pressure, thus making the coil unable to withstand higher pressure. However, if a lower pressure is used during the molding process, the density of the magnetic body will decrease and the inductance of the inductor or choke will also decrease. If the thickness of the insulated wire is increased, it is difficult to wind the insulated wire to form a coil and the volume of the coil is too large.

Therefore, the industry needs a better solution to solve the above-mentioned problems.

An object of the present invention is to add a coating layer to cover a coil to prevent particles of magnetic powder from piercing the insulating layer of the insulated wire during a molding process, thereby avoiding short circuit of the coil.

An object of the present invention is to add a covering layer to cover a coil to prevent the self-adhesive layer of the insulated wire from flowing out during a molding process.

An object of the present invention is to add a covering layer to cover a coil to increase the degree of insulation between the coil and the magnetic body, thereby allowing the coil to withstand higher voltages.

An embodiment of the present invention discloses a magnetic device. The magnetic device includes: a coil including a plurality of windings formed by an insulated wire, wherein the insulated wire includes a metal wire and at least a metal wire covering the metal wire. A first insulating layer, wherein at least two different parts of the coil form a first space; a coating layer, including an insulating material to cover and fill the at least two different parts of the coil Into the first space; and a magnetic body containing at least one magnetic powder, wherein the magnetic body encapsulates the plurality of windings of the insulated wire and the covering layer.

In an embodiment, the magnetic body has a single body that encapsulates the plurality of windings of the insulated wire and the covering layer, and the single body extends into the hollow portion of the coil.

In an embodiment, two different parts of two adjacent outer windings of the insulated wire form the first space, wherein the covering layer covers two different parts of two adjacent outer windings of the insulated wire. Part and extend into the first space.

In an embodiment, a first part of a winding of the insulated wire and a second part of a terminal portion of the insulated wire form the first space, wherein the covering layer covers the first part and the second part And extend into the first space.

In an embodiment, the first part of a winding of the insulated wire and the second part of a lead electrically connected to a terminal portion of the insulated wire form a second space, wherein the covering layer covers the The first part and the second part extend into the second space.

In an embodiment, the covering layer covers the entire outer surface of the plurality of windings.

In one embodiment, the magnetic device is an inductor.

In one embodiment, the insulated wire has only one insulation layer.

In an embodiment, the insulated wire has only two insulation layers, and the two insulation layers of the insulated wire are the first insulation layer and a self-adhesive layer covering the first insulation layer.

In one embodiment, the cover layer includes a polymer material.

In one embodiment, the cover layer includes a resin.

In one embodiment, the magnetic body includes a first magnetic powder, wherein the D50 of the first magnetic powder is between 17 and 36 microns, and the D10 of the first magnetic powder is between 8 and 26 microns. The D90 of the first magnetic powder is between 30 and 52 microns.

In one embodiment, the magnetic body includes a first magnetic powder, wherein the D50 of the first magnetic powder is between 8 and 16 microns, and the D10 of the first magnetic powder is between 3 and 6 microns. The D90 of the first magnetic powder is between 18 and 30 microns.

An embodiment of the present invention discloses a method for forming a magnetic device, including: providing a coil including a plurality of windings of an insulated wire, wherein the insulated wire includes a metal wire and at least A first insulating layer, wherein at least two different parts of the coil form a first space; forming a covering layer that includes an insulating material to cover and fill the at least two different parts of the coil Into the first space; and forming a magnetic book The magnetic body contains at least one magnetic powder, and the magnetic body encapsulates the plurality of windings of the insulated wire and the covering layer.

In an embodiment, the covering layer is formed by dripping the insulating material onto the at least two different parts of the insulated wire, wherein the insulating material is filled into the first space.

In one embodiment, the magnetic device is an inductor.

In one embodiment, the insulating material includes an adhesive, and the covering layer is formed by covering the at least two different parts of the insulated wire with the adhesive by dispensing or pouring, so The glue is filled into the first space.

In an embodiment, the insulated wire has only two insulation layers, and the two insulation layers of the insulated wire are the first insulation layer and a self-adhesive layer covering the first insulation layer.

In one embodiment, the cover layer includes a polymer material.

In one embodiment, the cover layer includes a resin.

In order to make the above-mentioned and other features and advantages of the present invention more comprehensible, the following specific examples are given in conjunction with the drawings, and detailed descriptions are made as follows.

101a: Metal wire

101b: first insulating layer

101c: second insulating layer

102: The First Space

103: Overlay

104: Magnetic body

105: different parts

106: different parts

201: Coil

205: insulated wire

206: terminal part

401: Step: Provide a coil of an insulated wire including a plurality of windings

402: Step: encapsulate at least two different parts of the insulated wire with a second insulating material

403: Step: Use a magnetic material containing at least one magnetic powder and a viscous material to encapsulate the plurality of windings of the insulated wire and the second insulating material

501: Step: Provide a coil of an insulated wire including a plurality of windings

502: Step: Form a cover layer

503: Step: Form a molded body

504: Step: Perform a hot pressing to solidify the molded body

505: Step: trim the lead frame

506: Step: Form two leads on the lower surface of the molded body to form the inductor

601: Step: Provide a coil of an insulated wire including a plurality of windings

602: Step: Form a cover layer

603: Step: Form a molded body

604: Step: trim the lead frame and remove unnecessary parts of the lead frame

605: Step: Form two leads on the lower surface of the molded body to form the inductor

The accompanying drawings are included to provide a further understanding of the present invention and the accompanying drawings are included in this specification and constitute a part of this specification. The drawings illustrate embodiments of the present invention and together with the description serve to explain the principle of the present invention.

FIG. 1 shows an enlarged cross-sectional view of a magnetic device according to an embodiment of the present invention. The magnetic device has a coil and a covering layer covering two different parts of the coil of the magnetic device.

2A-2B show a cross-sectional view of another embodiment of the present invention before and after adding a cover layer to cover two different parts of the coil of the magnetic device.

2C shows a cross-sectional view of a covering layer for covering at least two different parts of the coil of the magnetic device according to another embodiment of the present invention.

Fig. 2D shows a cross-sectional view of a covering layer for covering the entire outer surface of a plurality of windings of the coil according to another embodiment of the present invention.

Fig. 3 shows a magnetic device according to an embodiment of the present invention.

FIG. 4 shows a flowchart of a method for forming a magnetic device according to an embodiment of the present invention.

FIG. 5 shows a method for forming an inductor according to an embodiment of the present invention.

FIG. 6 shows a method for forming an inductor according to another embodiment of the present invention.

For the following description, D10, D50, and D90 are used to describe the particle size distribution of the magnetic powder. D10 means that 10% of the total number of particles is less than D10, D50 means that 50% of the total number of particles is less than D50, and D90 means that 90% of the total number of particles is less than D90.

1 shows an enlarged view of a cross-sectional view of a magnetic device according to an embodiment of the present invention, wherein the magnetic device includes a coil, the coil includes a plurality of windings of an insulated wire, wherein the insulated wire includes a metal wire 101a And at least one first insulating layer 101b of the encapsulated metal wire 101a, wherein at least two different parts 105, 106 of the insulated wire form a first space 102; a covering layer 103 made of a first insulating material, which covers At least two different parts 105, 106 of the coil are filled into the first space 102; and a magnetic body 104, wherein the magnetic body 104 contains at least one magnetic powder, wherein the magnetic body 104 encapsulates the plurality of windings of the insulated wire and Cover layer 103, In order to prevent the particles of the magnetic powder from damaging the at least one first insulating layer of the coil, so as to prevent the magnetic powder from piercing the insulating layer of the coil and causing a short circuit.

As shown in FIG. 1, the covering layer 103 covers the coil. When the magnetic body 104 is formed under pressure, the particles of the magnetic powder will not cause a short circuit between different parts of the coil. If the covering layer 103 is not present in the magnetic device, when the magnetic body 104 is formed under pressure, particles of magnetic powder can be arranged in the first space and pierce the insulating layer of the coil to short-circuit.

In one embodiment, the insulated wire has only one insulating layer: a first insulating layer 101b.

In one embodiment, the insulated wire has only two insulating layers: a first insulating layer 101b and a second insulating layer 101c.

In an embodiment, the second insulating layer 101c may be a self-adhesive layer, wherein the cover layer 103 covers the self-adhesive layer to prevent the self-adhesive layer from flowing out during the molding process. In addition, the covering layer 103 can further electrically isolate the coil from the particles of the magnetic powder to prevent the particles of the magnetic powder from causing a short circuit of the coil. In an embodiment, the insulated wire may be an enameled wire, wherein the enameled wire may have a circular shape. In one embodiment, the metal wire of the enameled wire includes copper.

FIG. 2A shows a coil 201 before the cover layer 103 is added. FIG. 2B shows the coil 201 after being covered by the covering layer 103. As shown in FIG. 2B, in an embodiment, two adjacent windings that are insulated and conductive form a first space 102 therebetween, and the insulating material of the cover layer 103 is filled into the first space 102.

2C shows a coil 201 in which a portion 206 of a winding of the insulated wire and a first portion 205 of a terminal portion of the insulated wire form the first space 102, in which the cover layer 103 The first insulating material is filled into the first space 102 to prevent particles of the magnetic powder from being disposed in the first space 102.

In an embodiment, as shown in FIG. 2D, the entire outer surface of the plurality of windings of the coil 201 is covered by the covering layer 103.

In an embodiment, the entire outer surface and the entire inner surface of the plurality of windings of the coil 201 are encapsulated by the cover layer 103.

In an embodiment, a first part of a winding of the insulated wire and a second part of a lead electrically connected to a terminal portion of the insulated wire form a second space, wherein the covering layer covers the The first part of the winding and the second part of the lead extend into the second space.

In an embodiment, the insulated wire has only one insulating layer: the first insulating layer 101b.

Please note that the covering layer 103 may only cover the part of the coil that is likely to be short-circuited by the particles of the magnetic powder. That is, the covering layer 103 does not have to cover the entire outer surface of the coil 201, as shown in FIG. 2C.

In an embodiment, the at least one first insulating layer includes two insulating layers, wherein the two insulating layers are made of different insulating materials.

In one embodiment, the magnetic device is an inductor.

In one embodiment, the cover layer includes a polymer material.

In one embodiment, the cover layer includes a resin.

In one embodiment, the cover layer includes an organic material.

In an embodiment, the magnetic body includes a first magnetic powder and a second magnetic powder, wherein the first magnetic powder and the second magnetic powder are mixed with a viscous material.

In one embodiment, the D50 of the first magnetic powder is between 8 and 36 microns, the D50 of the second magnetic powder is between 1.0 and 10 microns, and the D10 of the first magnetic powder is between 3 and 20 microns. The D10 of the two magnetic powders is between 0.5 and 6 microns, the D90 of the first magnetic powder is between 20 and 60 microns, and the D90 of the second magnetic powder is between 2 and 12 microns.

In an embodiment, the magnetic body includes a first magnetic powder, wherein the D50 of the first magnetic powder is between 17 and 36 microns, the D10 of the first magnetic powder is between 8 and 26 microns, and the D90 of the first magnetic powder is between 8 and 26 microns. Between 30 and 52 microns.

In one embodiment, the magnetic body includes a first magnetic powder, wherein the D50 of the first magnetic powder is between 8 and 16 microns, the D10 of the first magnetic powder is between 3 and 6 microns, and the D90 of the first magnetic powder is Between 18 and 30 microns.

3 shows a magnetic device according to an embodiment of the present invention, wherein the magnetic device includes: a coil 201, the coil 201 includes a plurality of windings formed by an insulated wire, wherein the insulated wire includes a metal wire and at least one first insulating layer To encapsulate the metal wire, the insulated wire can be a suitable shape, such as a round wire, wherein at least two different parts of the coil 201 form a first space 102; a covering layer 103 covers the at least two different parts of the coil 201 And extends into the first space 102; a magnetic body 104 is formed of at least one magnetic powder and a viscous material, wherein the magnetic body 104 encapsulates a plurality of windings of the insulated wire of the coil 201.

In an embodiment, the magnetic body 104 encapsulates a plurality of windings of the coil 201 and extends into the hollow part of the coil 201.

In an embodiment, the covering layer 103 extends into the hollow portion of the coil 201 to cover an inner surface of the coil 201.

In one embodiment, a lead 140 is provided on the magnetic body 104 and electrically connected to the coil 201.

As shown in FIG. 3, the covering layer 103 covers the coil 201. When the magnetic body 104 is formed under pressure, the particles of the magnetic powder will not cause a short circuit between different parts of the coil 201. If the covering layer 103 is not present in the magnetic device, when the magnetic body 104 is formed under pressure, particles of magnetic powder may be arranged in the first space 102 to damage the insulating layer of the coil 201 and cause at least two differences in the coil 201 Short circuit between parts.

4 shows a flow chart of a method for forming a magnetic device. The method includes: in step 401: providing a coil including a plurality of windings of an insulated wire, wherein the insulated wire includes a metal wire And at least one first insulating layer covering the metal wire, wherein at least two different parts of the coil form a first space; in step 402: forming a covering layer which includes an insulating material to cover The at least two different parts of the coil are filled into the first space; in step 403: a magnetic body is formed, the magnetic body includes at least one magnetic powder, wherein the magnetic body encapsulates a plurality of insulated wires Winding and the covering layer.

In an embodiment, two adjacent windings that are insulated and conductive form a first space 102 therebetween, and the first insulating material of the covering layer 103 is filled into the first space 102 to prevent at least one particle of at least one magnetic powder from being disposed in the first space 102. In the first space.

There are many ways to cover at least two different parts of the insulated wire with insulating material, such as dipping or immersing at least two different parts of the insulated wire in the insulating material, or spraying the insulating material on at least two of the insulated wires. On different parts, or dip the insulating material onto the The at least two different parts of the insulated wire. In one embodiment, the insulating material includes an adhesive, and the covering layer is formed by covering at least two different parts of the insulated wire with the adhesive by dispensing or pouring, the The glue is filled into the space formed by the at least two different parts.

FIG. 5 shows a method for forming an inductor according to an embodiment of the invention. As shown in FIG. 5, the method includes: in step 501: providing a coil including a plurality of windings of an insulated wire, wherein the insulated wire includes a metal wire and at least one first insulated wire covering the metal wire Layer, wherein the two terminals of the coil are electrically connected to a lead frame; in step 502: forming a covering layer to cover at least a part of the plurality of windings, wherein the covering layer includes a second insulating material, the second The insulating material is filled into the space formed by the different parts of the coil; in step 503: forming a molded body, encapsulating the plurality of windings and the covering layer, wherein the molded body includes at least one magnetic powder and a viscous material To mix the particles in the at least one magnetic powder; in step 504: perform a hot pressing to solidify the molded body; in step 505: remove unnecessary parts in the lead frame; in step 506: in the molding Two leads are formed on the bottom surface of the body to form the inductor.

Fig. 6 shows a method for forming an inductor according to an embodiment of the present invention. As shown in FIG. 6, the method includes: in step 601: providing a coil including a plurality of windings of an insulated wire, wherein the insulated wire includes a metal wire and at least one first insulated wire covering the metal wire Layer, wherein the two terminals of the coil are electrically connected to a lead frame; in step 602: forming a covering layer to cover at least a part of the plurality of windings, wherein the covering layer includes a second insulating material, the second The insulating material is filled into the space formed by the different parts of the coil; in step 603: forming a molded body, encapsulating the plurality of windings and the covering layer, wherein the molded body contains to One less magnetic powder and one viscous material are used to mix the particles in the at least one magnetic powder, wherein the molded body is solidified without thermal processing; in step 604: remove unnecessary parts in the lead frame; In step 605: two leads are formed on the lower surface of the molded body to form the inductor. The present invention has many advantages: (1) The covering layer can make the coil to withstand higher molding pressure to prevent the coil from being pressed into the magnetic powder. When the magnetic body is short-circuited; (2) The cover layer can prevent the self-adhesive layer of the insulated wire from flowing and overflowing during the molding process; (3) Increase the degree of insulation between the coil and the magnetic powder; (4) Enable the coil to withstand higher Voltage.

Although the present invention has been described with reference to the above-mentioned embodiments, it is obvious to those skilled in the art that the described embodiments can be modified without departing from the spirit of the present invention. Therefore, the scope of the present invention will be defined by the appended claims rather than the above detailed description.

101a: Metal wire

101b: first insulating layer

101c: second insulating layer

102: The First Space

103: Overlay

104: Magnetic body

105: different parts

106: different parts

Claims (8)

An inductor that contains: A coil comprising at least one winding formed by an insulated wire, wherein the insulated wire comprises a metal wire and at least one first insulating layer covering the metal wire, wherein at least two different parts of the insulated wire Form a first space; A coating layer including an insulating material to cover at least two different parts of the insulated wire and fill the first space; and A magnetic body containing at least one magnetic powder, wherein the magnetic body encapsulates the at least one winding of the insulated wire and the covering layer. An inductor that contains: A coil, the coil includes a plurality of windings formed by an insulated wire, wherein the insulated wire includes a metal wire and at least one first insulating layer covering the metal wire, wherein at least two of the insulated wires are different Partly form a first space; A coating layer including an insulating material to cover at least two different parts of the insulated wire and fill the first space; and A magnetic body comprising at least one magnetic powder, wherein the magnetic body has a single body, the single body encapsulates the plurality of windings of the insulated wire and the covering layer, and the single body extends to the coil In the hollow part. An inductor that contains: A coil, the coil includes a plurality of windings formed by an insulated wire, wherein the insulated wire includes a metal wire and at least one first insulating layer covering the metal wire, wherein a first winding of the insulated wire A part and a second part of a terminal part of the insulated wire form a first space; A coating layer including an insulating material to cover at least two different parts of the insulated wire and fill the first space; and A magnetic body containing at least one magnetic powder, wherein the magnetic body encapsulates the plurality of windings of the insulated wire and the covering layer. An inductor that contains: A coil, the coil includes a plurality of windings formed by an insulated wire, wherein the insulated wire includes a metal wire and at least one first insulating layer covering the metal wire, wherein the first part of a winding of the insulated wire And a second part of a lead electrically connected to a terminal part of the insulated wire to form a first space; A coating layer including an insulating material to cover at least two different parts of the insulated wire and fill the first space; and A magnetic body containing at least one magnetic powder, wherein the magnetic body encapsulates the plurality of windings of the insulated wire and the covering layer. An inductor that contains: A coil, the coil includes a plurality of windings formed by an insulated wire, wherein the insulated wire includes a metal wire and two insulating layers covering the metal wire, wherein the two insulating layers are a first insulation Layer and a self-adhesive layer covering the first insulating layer, wherein at least two different parts of the insulated wire form a first space; A coating layer including an insulating material to cover at least two different parts of the insulated wire and fill the first space; and A magnetic body containing at least one magnetic powder, wherein the magnetic body encapsulates the plurality of windings of the insulated wire and the covering layer. A method for forming an inductor includes: A coil is provided, the coil includes a plurality of windings formed by an insulated wire, wherein the insulated wire includes a metal wire and at least one first insulating layer covering the metal wire, wherein at least two of the insulated wires are different Partly form a first space; Forming a covering layer that includes an insulating material to cover the at least two different parts of the insulated wire and fill the first space; and A magnetic body is formed, the magnetic body includes at least one magnetic powder, and the magnetic body encapsulates the plurality of windings of the insulated wire and the covering layer. A method for forming an inductor includes: A coil is provided, the coil includes a plurality of windings formed by an insulated wire, wherein the insulated wire includes a metal wire and two insulating layers covering the metal wire, wherein the two insulating layers are a first insulation Layer and a self-adhesive layer covering the first insulating layer, wherein at least two different parts of the insulated wire form a first space; Forming a covering layer that includes an insulating material to cover the at least two different parts of the insulated wire and fill the first space; and A magnetic body is formed, the magnetic body includes at least one magnetic powder, and the magnetic body encapsulates the plurality of windings of the insulated wire and the covering layer. A method for forming an inductor includes: A coil is provided, the coil includes a plurality of windings formed by an insulated wire, wherein the insulated wire includes a metal wire and at least one first insulating layer covering the metal wire, wherein at least two of the insulated wires are different Partly form a first space; A covering layer is formed, the covering layer includes an insulating material to cover the at least two different parts of the insulated wire and fills the first space, wherein the insulating material includes a glue, and the covering layer is passed through The adhesive is formed by covering the at least two different parts of the insulated wire in a dispensing or pouring manner, and the adhesive is filled into the first space; and A magnetic body is formed, the magnetic body includes at least one magnetic powder, and the magnetic body encapsulates the plurality of windings of the insulated wire and the covering layer.

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