CN111627669A

CN111627669A - Magnetic element and preparation method thereof

Info

Publication number: CN111627669A
Application number: CN202010449802.6A
Authority: CN
Inventors: 赵宜泰; 李玄; 周小兵; 赵家彦
Original assignee: Kunshan Maji Electronics Co ltd
Current assignee: Kunshan Maji Electronics Co ltd
Priority date: 2020-05-25
Filing date: 2020-05-25
Publication date: 2020-09-04
Anticipated expiration: 2040-05-25
Also published as: CN111627669B

Abstract

The invention relates to the technical field of electronic components, and particularly discloses a magnetic element and a preparation method thereof. The magnetic element comprises a sheet-shaped magnetic core, a lead and a magnetic body. The chip core includes opposite first and second faces; the lead is provided with a coil section and a connecting section led out from the end part of the coil section, the coil section is arranged on the first surface, and the connecting section is in limit connection with the flaky magnetic core; the magnetic body at least covers the sheet-shaped magnetic core and the coil section of the lead, and the connecting section of the lead is at least partially exposed outside the magnetic body. The arrangement of the flaky magnetic core can realize the positioning of the whole lead, and the condition that the coil is deformed or misplaced in the pressing process is avoided. The connecting section does not need to be connected with the lead frame, because the coil section can be arranged in a maximized mode, the magnetic performance of the magnetic element is improved, and the effect of optimizing the energy conversion and storage performance of the magnetic element is achieved.

Description

Magnetic element and preparation method thereof

Technical Field

The invention relates to the technical field of electronic components, in particular to a magnetic element and a preparation method thereof.

Background

In the field of electronics, magnetic elements are the core components of energy conversion and storage, and their performance is related to the efficiency and performance of the overall system. The magnetic element mainly includes an inductor and a transformer, wherein, taking the inductor as an example, the inductor is an element capable of converting electric energy into magnetic energy and storing the magnetic energy, and is also called a choke, a reactor or a dynamic reactor.

The conventional inductor is usually manufactured by first welding the inner and outer ends of the air-core coil to two different connecting terminals on the lead frame, then injecting a powder molding material into a mold in a manner of completely surrounding the air-core coil, then performing press molding by a powder molding machine, finally cutting off the lead frame, and folding the leads onto the bottom surface of the inductor. However, the above method is limited by the lead frame, so that the air-core coil cannot be maximized and the magnetic performance cannot be optimized; and the coil can not be positioned, and is easy to be damaged or deformed or dislocated in the pressing process, so that the quality of a finished product is influenced. Similarly, other magnetic elements similar to inductors have the same drawbacks as described above.

Disclosure of Invention

In view of the above, it is necessary to provide a magnetic element and a method for manufacturing the same, which are directed to the problems that the magnetic properties of the magnetic element cannot be optimally exerted and the coil is easily deformed.

A magnetic element, comprising:

a chip magnetic core including opposing first and second faces;

the wire is provided with a coil section and a connecting section led out from the end part of the coil section, the coil section is arranged on the first surface, and the connecting section is in limit connection with the flaky magnetic core;

and the magnetic body at least covers the sheet-shaped magnetic core and the coil section of the lead, and the connecting section of the lead is at least partially exposed outside the magnetic body.

In one embodiment, the material of the sheet-shaped magnetic core is one or more of an alloy magnetic material, an amorphous material, ferrite and carbonyl iron.

In one embodiment, an orthographic projection of the coil segment on the first face is located within the first face.

In one embodiment, the coil segment includes a first end and a second end opposite to each other, and the connection segment includes a first segment connected to the first end and a second segment connected to the second end, and the first segment and the second segment are symmetrically disposed on both sides of the coil segment.

In one embodiment, the first section and the second section are U-shaped structures formed by bending the wire from the first face to the second face.

In one embodiment, the side of the chip magnetic core is provided with a groove, and the U-shaped structure is clamped in the groove.

In one embodiment, the wire is a strip wire or a round wire.

In one embodiment, the magnetic body is formed by mixing at least two of iron-based amorphous powder, sendust powder, permalloy powder, sendust powder and nano-crystalline alloy powder.

In one embodiment, the surface of the connecting section exposed outside the magnetic body is coated with a metal layer.

A method of making a magnetic element as described above, the method comprising:

winding a lead to form a coil section, and leading out a connecting section from the end part of the coil section;

placing the coil section on the first surface of the flaky magnetic core, and connecting the connecting section with the flaky magnetic core in a limiting manner to complete the assembly of the lead and the flaky magnetic core;

placing the assembled lead and the sheet-shaped magnetic core in a mold, filling a magnetic material in the mold, and obtaining a magnetic body completely coating the sheet-shaped magnetic core and the lead through a hot press molding process;

the magnetic body is polished to expose the connection section portion of the lead.

In one embodiment, before the step of grinding the magnetic body, the method further includes:

and baking the magnetic body.

In one embodiment, the wire is an enameled wire; after the step of grinding the magnetic body to expose the connection section portion of the lead, the method further includes:

removing the paint on the connecting section of the exposed lead;

and forming a metal layer on the surface of the connecting section from which the paint is removed.

The magnetic element comprises a sheet magnetic core, a lead and a magnetic body, wherein the sheet magnetic core comprises a first surface and a second surface which are opposite, the lead comprises a coil section and a connecting section, the coil section is positioned on the first surface of the sheet magnetic core, the connecting section is in limit connection with the sheet magnetic core, the magnetic body at least covers the sheet magnetic core and the coil section, and at least part of the connecting section is exposed outside the magnetic body. Above-mentioned slice magnetic core's setting, on the one hand, can be through with the spacing connection of linkage segment, realize spacing coil section and whole wire, avoid the coil to appear warping or the condition of dislocation in the pressing process, improve finished product quality. On the other hand, because the connection section need not to be connected with the lead frame, consequently, the position of connection section does not receive the restriction of lead frame, and namely, the tip of coil section can not receive the restriction of lead frame, and the coil section can set to actual required size, because can set up the coil section maximize, further promotes this magnetic element's magnetic property, and then reaches the effect of optimizing its energy conversion and storage performance.

Drawings

FIG. 1 is an exploded view of a magnetic element according to one embodiment;

FIG. 2 is a schematic diagram of a conductive line of a magnetic element according to an embodiment;

FIG. 3 is a schematic view of an embodiment of an assembled magnetic element;

FIG. 4 is an exploded view of a magnetic element according to another embodiment;

FIG. 5 is a schematic view of an assembly of a magnetic element according to another embodiment;

FIG. 6 is a block flow diagram of a method of fabricating a magnetic element according to one embodiment;

FIG. 7 is a block flow diagram of a method of fabricating a magnetic element according to another embodiment;

fig. 8 is a block flow diagram of a method for manufacturing a magnetic element according to yet another embodiment.

The reference numbers illustrate:

10. a sheet-like magnetic core; 101. a first side; 102. a second face; 103. a groove; 20. a wire; 201. a coil segment; 2011. a first end; 2012. a second end; 202. a connecting section; 2021. a first stage; 2022. a second stage; 30. a magnetic body.

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the terms "vertical," "horizontal," "left," "right," "upper," "lower," "front," "rear," "circumferential," and the like are based on the orientation or positional relationship shown in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As described in the background, the conventional inductor manufacturing process is required to rely on a lead frame. Firstly, winding a wire into a coil; then welding leads at two ends of the coil on the lead frame; then the structure is placed into a mould, a powdery molding material is injected into the mould, and the mould is pressed and formed by a powder forming machine; and finally, cutting off the lead frame to form the final inductor.

The inductor is manufactured by applying the lead frame, and two ends of the lead are welded with two extending ends of the lead frame, so that the size of the wound coil needs to be adapted to the size of the lead frame and is not easy to be too large, and the magnetic performance of the manufactured inductor is limited. In addition, before pressing, the two end parts of the coil are fixed only by the lead frame, and the whole coil cannot be fixed, so that the coil is easy to damage, deform or misplace in the pressing forming process, and the quality of a finished product is further influenced.

Similarly, various magnetic elements such as transformers, which are close to the inductor manufacturing process, have the above problems.

In order to solve the above problem, embodiments of the present application provide a magnetic element, which may be an inductor, a transformer, or another magnetic element. In this embodiment, an inductor is taken as an example for explanation.

As shown in fig. 1 to 5, the present embodiment provides a magnetic element including a chip core 10, a conductive wire 20, and a magnetic body 30. Wherein the chip core 10 comprises a first face 101 and a second face 102 opposite thereto; the lead 20 has a coil segment 201 and a connection segment 202 led out from the end of the coil segment 201, the coil segment 201 is arranged on the first surface 101 of the sheet-shaped magnetic core 10, and the connection segment 202 is in limit connection with the sheet-shaped magnetic core 10; the magnetic body 30 covers at least the chip core 10 and the coil segment 201 of the lead wire 20, and the connection segment 202 of the lead wire 20 is at least partially exposed outside the magnetic body 30.

Specifically, the chip magnetic core 10 has a rectangular parallelepiped structure. The first surface 101 and the second surface 102 of the chip core 10 are the front and back surfaces of the chip core 10, and in this embodiment, the first surface 101 of the chip core 10 is defined as the front surface, and the second surface 102 of the chip core 10 is defined as the back surface.

In one embodiment, the material of the sheet-like magnetic core 10 may be one or more of an alloy magnetic material, an amorphous material, a ferrite, and carbonyl iron. Specifically, the chip core 10 is formed by pressing a mixed material of one or more materials of an alloy magnetic material, an amorphous material, ferrite, and carbonyl iron. The loss of the magnetic core formed by pressing the materials is low. Of course, other materials can be selected and mixed according to actual requirements, and are not listed here.

In one embodiment, the wires 20 are strip wires or round wires, wherein fig. 1 is a round wire and fig. 4 is a strip wire. Both the strip-shaped lead and the round lead are suitable for the scheme. As a preferred embodiment, a round wire is selected in this embodiment. The round wire is widely applied and is regularly wound into a coil. The wire 20 in this embodiment may be an enameled wire, and the enameled wire is composed of a conductor and an insulating layer covering the conductor.

The wire 20 includes a coil segment 201 and a connection segment 202, wherein the coil segment 201 is a spiral structure formed by winding the wire 20, and the connection segment 202 is a segment of wire led out from an end of the coil segment 201.

In one embodiment, coil segment 201 includes first 2011 and second 2012 opposite ends, connection segment 202 includes first 2021 and second 2022 segments, first segment 2021 of connection segment 202 is connected to first end 2011 of coil segment 201, second segment 2022 of connection segment 202 is connected to second end 2012 of coil segment 201, and first 2021 and second 2022 segments are symmetrically disposed on opposite sides of coil segment 201. Generally, the first end 2011 and the second end 2012 of the coil segment 201 are respectively located in two opposite winding directions of the coil segment 201 and symmetrically located on two sides of the coil segment 201, where the two sides of the coil segment 201 refer to two circumferential sides of the coil segment 201.

It should be noted that the connection segment 202 and the coil segment 201 may be an integral structure, that is, the connection segment 202 is formed by processing the end of the coil segment 201, for example, bending the end of the coil segment 201 to form the connection segment 202; the connection segment 202 and the coil segment 201 may be of separate structures, that is, there may be two separate components between the connection segment 202 and the coil segment 201, and in practical applications, the connection segment 202 and the coil segment 201 are connected together in combination.

In this embodiment, the coil segment 201 is located on the first face 101 of the chip core 10, i.e. the chip core 10 acts as a position-limiting and load-bearing for the coil segment 201.

In one embodiment, the orthographic projection of the coil segment 201 on the first surface 101 is located in the first surface 101, that is, the coil segment 201 does not exceed the boundary of the first surface, so as to ensure that the U-shaped magnetic core has a complete limiting and bearing effect on the coil segment.

In one embodiment, the first section 2021 and the second section 2022 are U-shaped structures formed by bending the wire 20 from the first surface 101 of the U-shaped magnetic core 10 to the second surface 102 of the U-shaped magnetic core 10. That is, the connection section 202 is connected to the chip core 10 in a limited manner, and the entire wire 20 is further positioned by the U-shaped core 10.

As a further alternative, in this embodiment, the side of the U-shaped magnetic core 10 is provided with a groove 103, and the U-shaped structure is clamped in the groove 103. The side of the U-shaped magnetic core 10 is the side of the U-shaped magnetic core 10 passing through when being bent into the U-shaped structure, and because of the two connecting sections 202, the same side of the U-shaped magnetic core 10 is provided with two grooves 103 corresponding to the two connecting sections 202, respectively, and the middle bent part of the U-shaped structure is clamped in the groove 103.

As a further alternative, in this embodiment, a groove may also be disposed on the second surface 102 of the U-shaped magnetic core 10, and in practical applications, the connecting section 202 bent to the second surface 102 may be embedded in the groove disposed on the second surface 102, thereby further enhancing the tight connection with the connecting section 202 and the limitation of the entire wire 20.

In one embodiment, the magnetic body 30 is formed by mixing at least two of fe-based amorphous powder, sendust powder, permalloy powder, sendust powder, and nano-crystalline alloy powder. Specifically, the magnetic body 30 is formed by mixing and pressing at least two materials selected from an iron-based amorphous powder, an sendust powder, a permalloy powder, a sendust powder, and a nanocrystalline alloy powder by a hot press molding process. In addition to the above materials, thermosetting materials such as resins may be added and co-pressed with the above materials.

The magnetic body 30 may be in the shape of a rectangular parallelepiped housing, or may be in other shapes, which depends on the shape of the mold used in the hot press molding process, and is not limited herein.

In this embodiment, the connecting section 202 of the lead 20 is at least partially exposed outside the magnetic body 30. When the connecting section 202 is in the U-shaped structure, the portion of the connecting section 202 located on the second surface 102 of the U-shaped magnetic core 10 is exposed outside the magnetic body 30; the free end of the connection segment 202 not connected to the coil segment 201 may be exposed to the outside of the magnetic body 30.

In one embodiment, the surface of the connecting segment 202 exposed outside the magnetic body 30 is coated with a metal layer. The metal layer is disposed to electrically connect the connection segment 202 to the circuit, so as to exert the electrical function of the magnetic element. The metal layer may be a metal silver layer.

The magnetic element comprises a sheet-shaped magnetic core 10, a conducting wire 20 and a magnetic body 30, wherein the sheet-shaped magnetic core 10 comprises a first surface 101 and a second surface 102 which are opposite, the conducting wire 20 comprises a coil section 201 and a connecting section 202, the coil section 201 is positioned on the first surface 101 of the sheet-shaped magnetic core 10, the connecting section 202 is in limit connection with the sheet-shaped magnetic core 10, the magnetic body 30 at least covers the sheet-shaped magnetic core 10 and the coil section 201, and at least part of the connecting section 202 is exposed outside the magnetic body 30. Above-mentioned chip core 10's setting, on the one hand, can be through with the spacing connection of linkage segment 202, realize spacing coil section 201 and whole wire 20, avoid the coil to appear warping or the condition of dislocation in the pressing process, improve finished product quality. On the other hand, since the connection segments 202 are not required to be connected to the lead frame, the positions of the connection segments 202 are not limited by the lead frame, that is, the ends of the coil segments 201 may not be limited by the lead frame, and the coil segments 201 may be set to an actual required size, because the coil segments 201 may be maximally set, the magnetic performance of the magnetic element is further improved, and the effect of optimizing the energy conversion and storage performance is further achieved.

The embodiment of the application also provides a preparation method of the magnetic element. As shown in fig. 6, a method for manufacturing a magnetic element provided in an embodiment of the present application includes the following steps:

step S20: the wire 20 is wound to form the coil segment 201, and the connection segment 202 is led out from the end of the coil segment 201.

Specifically, one end of the wire 20 may be held stationary and the other end of the wire 20 may be pulled around the coil segment 201 forming the wire 20. It is also possible to keep the middle portion of the wire 20 stationary while pulling the two ends of the wire 20 in opposite directions around the coil segment 201 forming the wire 20.

The coil segment 201 has a first end 2011 and a second end 2012 (i.e., one end and the other end of the wire 20), and the connection segment 202 may be formed by processing one end and the second end 2012 of the coil segment 201 or connected to the end of the coil segment 201. Corresponding to the first and

second ends

2011, 2012 of the coil segment 201, the connecting segment 202 has a first segment 2021 connected to the first end 2011 and a second segment 2022 connected to the second end 2012, and the first and

second segments

2021, 2022 of the connecting segment 202 may be U-shaped.

The first section 2021 of the connecting section 202 is taken as an example for explanation: when the first section 2021 of the connection section 202 is U-shaped, the U-shape is disposed adjacent to the coil section 201, and the U-shape is located in a vertical direction.

In one embodiment, the wire 20 is a ribbon wire or a round wire. Both the strip-shaped lead and the round lead are suitable for the scheme. As a preferred embodiment, a round wire is selected in this embodiment. The round wire is widely applied and is regularly wound into a coil. The wire 20 in this embodiment may be an enameled wire, and the enameled wire is composed of a conductor and an insulating layer covering the conductor.

Step S40: the coil segment 201 is placed on the first face 101 of the chip core 10, and the connection segment 202 is connected to the chip core 10 to complete the assembly of the wire 20 and the chip core 10.

Taking the U-shaped connection segment 202 as an example, when the lead wire 20 and the chip core 10 are assembled, the U-shaped connection segment 202 is engaged with the chip core 10 in a direction approaching the chip core 10, and the coil segment 201 is fixed to the first surface 101 of the chip core 10.

In step S20, the U-shaped structure of the connection segment 202 may not be formed, but only the connection segment 202 may be drawn out from both ends of the coil segment 201, and the connection segment is formed when assembling in step S40, that is, the coil segment 201 is placed on the first surface 101 of the sheet-shaped magnetic core 10, and then the connection segment 202 is bent from the first surface 101 of the sheet-shaped magnetic core 10 to the second surface 102 of the sheet-shaped magnetic core 10 through the side edge of the sheet-shaped magnetic core 10 to form the U-shaped structure, thereby realizing the limit connection between the connection segment 202 and the sheet-shaped magnetic core 10.

Step S60: the assembled lead 20 and the sheet-shaped magnetic core 10 are placed in a mold, a magnetic material is filled in the mold, and the magnetic body 30 completely covering the sheet-shaped magnetic core 10 and the lead 20 is obtained through a hot press molding process.

Wherein, the mold has a structure with one side open, and is generally rectangular. The magnetic material includes at least two of iron-based amorphous powder, sendust powder, permalloy powder, sendust powder, and nanocrystalline alloy powder, and the magnetic material further includes a thermosetting material such as resin. The magnetic material completely covering the chip core 10 and the lead wire 20 is pressed by a hot press process, and finally the magnetic body 30 completely covering the chip core 10 and the lead wire 20 is formed. Parameters involved in the hot pressing process, such as time and pressure, can be set according to actual requirements, and are not specifically limited herein.

Step S80: the magnetic body 30 is polished so that the connection section 202 of the lead 20 is partially exposed.

After the magnetic body 30 is pressed, the magnetic body 30 is polished by a polishing process, and the polishing position is mainly determined by the position of the connecting section 202, so that the connecting section 202 is partially exposed. How much the connecting section 202 is exposed can be determined according to actual requirements.

In one embodiment, as shown in fig. 7, before step S80, that is, the step of grinding the magnetic body 30, the method for manufacturing a magnetic element provided in the embodiment of the present application further includes the following steps:

step S70: the magnetic body 30 is baked. After the magnetic body 30 is pressed, the magnetic body 30 needs to be baked and cured. The time for baking and curing can be determined according to actual requirements.

In one embodiment, the wire 20 is an enameled wire; as shown in fig. 8, after step S80, that is, the step of grinding the magnetic body 30 to expose the connection section 202 of the lead 20, the method for manufacturing a magnetic element according to the embodiment of the present application further includes the following steps:

step S81: the paint on the connecting section 202 of the exposed wire 20 is removed. Because enameled wires are used, the exposed outer side of the connecting section 202 of the wire 20 has a layer of enamel, and the enamel layer on the outer side of the connecting section 202 can be removed by a laser stripping process.

Step S82: a metal layer is formed on the surface of the connection section 202 from which the paint is removed. After the paint is removed, a metal layer, which may be a silver layer, may be formed on the periphery of the connection segment 202 by an electroplating process. The metal layer is disposed to electrically connect the connection segment 202 to the circuit, so as to exert the electrical function of the magnetic element.

According to the preparation method of the magnetic element, on one hand, the coil section 201 can be arranged in a maximized mode without depending on a lead frame, the magnetic performance of the magnetic element is improved, and the effects of optimizing the energy conversion and storage performance of the magnetic element are achieved. On the other hand, the arrangement of the sheet-shaped magnetic core 10 can realize the limitation of the coil segment 201 and the whole lead 20 by the limit connection with the connecting segment 202, thereby avoiding the deformation or dislocation of the coil in the pressing process and improving the quality of finished products.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A magnetic element, comprising:

a chip magnetic core including opposing first and second faces;

a magnetic body at least covering the chip core and the coil segment of the wire, the connection segment of the wire being at least partially exposed outside the magnetic body.

2. The magnetic component of claim 1, wherein the material of the sheet core is one or more of an alloy magnetic material, an amorphous material, a ferrite, and a carbonyl iron.

3. The magnetic element of claim 1, wherein an orthographic projection of the coil segment on the first face is within the first face.

4. The magnetic component of claim 1, wherein the coil segment includes opposing first and second ends, and wherein the connection segment includes a first segment connected to the first end and a second segment connected to the second end, the first and second segments being symmetrically disposed on opposite sides of the coil segment.

5. The magnetic element of claim 4, wherein the first and second segments are U-shaped structures formed by bending the wire from the first face to the second face.

6. The magnetic component of claim 5, wherein the side of the chip core is provided with a groove, and the U-shaped structure is clamped in the groove.

7. The magnetic element of claim 1, wherein the wire is a ribbon wire or a round wire.

8. The magnetic element according to claim 1, wherein the magnetic body is formed by mixing at least two materials selected from the group consisting of iron-based amorphous powder, sendust powder, permalloy powder, sendust powder, and nanocrystalline alloy powder.

9. The magnetic element of claim 1, wherein a surface of the connecting segment exposed outside the magnetic body is coated with a metal layer.

10. A method of manufacturing a magnetic element as claimed in any one of claims 1 to 9, the method comprising:

placing the coil section on a first surface of a sheet-shaped magnetic core, and connecting the connecting section with the sheet-shaped magnetic core in a limiting manner to complete the assembly of the lead and the sheet-shaped magnetic core;

placing the assembled lead and the sheet magnetic core in a mold, filling a magnetic material in the mold, and obtaining a magnetic body completely coating the sheet magnetic core and the lead through a hot press molding process;

and grinding the magnetic body to expose the connecting section part of the lead.

11. The method of manufacturing a magnetic element according to claim 10, wherein before the step of grinding the magnetic body, the method further comprises:

and baking the magnetic body.

12. The method of manufacturing a magnetic element according to claim 10, wherein the wire is an enameled wire; after the step of grinding the magnetic body, the method further includes:

removing paint on the exposed connecting section of the lead;

and forming a metal layer on the surface of the connecting section with the paint removed.