CN105702426A - Planar coil, manufacturing method and planar transformer - Google Patents

Abstract

The present invention provides a planar coil comprising a continuous material formed from: an inner coil stack, an outer coil stack, and a connecting portion connecting the inner coil stack and the outer coil stack in series. The inner coil stack and the outer coil stack each include a plurality of planar coil layers connected in series. The connecting portion connects the windings of the inner coil stack and the outer coil stack at the same height. The inner or outer coil stack may also include an extended pad. The planar coil may also include a coil stack positioned between the two coil stacks. The invention also discloses a method for manufacturing the planar coil and a planar transformer using the coil.

Description

Planar coil, manufacturing method and planar transformer

technical field

The invention relates to a planar coil and its manufacturing method, and a planar transformer using the planar coil, in particular to a multilayer planar coil module that can be made of continuous materials.

Background technique

Transformers are critical components in powering electronics. Existing transformers are bulky and cannot meet the requirements of product miniaturization. Planar transformer (Planar transformer, or planar transformer) is a transformer formed by laying copper foil and other conductive foils as windings on a multilayer printed circuit board (Printed circuit board, PCB), and stacking them, which can greatly reduce the thickness of the transformer. Planar transformers are widely used in communication, computer, industrial control, aerospace engineering, medical equipment and other products. However, because the planar transformer needs to use quite a multi-layer circuit board, the volume is still large. And because the efficiency is not high, the output impedance is also large, and it is easy to generate noise. How to achieve thinner and higher efficiency of planar transformers has become a technical problem that needs to be overcome urgently in this industry.

Taiwan Invention Patent No. I357086 provides a transformer suitable for being arranged in a circuit board. The transformer includes a first planar coil and a second planar coil, wherein the first planar coil has several first windings, and the second planar coil has several second windings. At least two adjacent first coils form a first coil bundle. At least two adjacent second coils form a second coil bundle. The two straddle each other, thereby reducing the number of layers of the planar coil.

Chinese invention patent CN103081044A discloses a planar transformer, which has multi-layer single-layer and single-turn winding boards, and different types of planar transformers are formed by combining different winding boards according to different needs.

European patent EP2602801A1 discloses a planar transformer with several single-layer, single-turn wound metal plates as secondary windings to be combined with primary windings.

European patent EP2637183A2 discloses a planar transformer using a single-layer single-turn winding board as a coil. The winding board is extended into a pad shape to serve as connection electrodes between layers and with the outside world.

US Patent Publication No. 2013-278371A1 discloses a planar transformer, which uses a plurality of single-layer planar metal windings, and connects and positions the plurality of metal windings in series with terminals to achieve the purpose of multi-layer winding.

Patent Cooperation Treaty patent WO0070926A1 also discloses a planar transformer, which uses continuous material to make multi-layer, single-turn winding plates. The layers are connected in series by pad-shaped tongues.

US Patent No. 8,237,535B2 discloses a planar transformer formed by stacking and combining multi-layer coil plates or coil layers. Each coil layer includes a single-turn coil.

US Patent No. 8,395,470B2 discloses a planar transformer formed by stacking and combining multi-layer coil plates or coil layers. Each coil layer includes a single-turn coil, and the pads arranged at different relative positions are connected in series.

US Patent Publication No. 2014/0145813 discloses a planar high-voltage transformer, which is formed by stacking and combining multiple layers of coil plates. Each coil plate includes a multi-turn coil. The winding of the coil starts from the outer circumference of the coil plate and ends at the inner circumference.

From the technical status of planar transformers, it can be seen that the industry has spared no efforts in the development of the miniaturization of planar transformers, so as to get rid of the existing pattern of making planar transformers with printed circuit boards. The proposed designs mostly use single-layer winding boards, coil boards or coil layers as combined units. However, it is impossible to propose a planar transformer structure that can change the voltage conversion ratio of the transformer by increasing or decreasing the number of coil plates or coil layers and the number of windings according to the needs of use. The prior art also does not propose a technology that can make planar coils from continuous materials.

Contents of the invention

The purpose of the present invention is to provide a multi-layer planar coil structure made of continuous material.

Another object of the present invention is to provide a planar coil that can easily change the number of layers and turns of the planar coil in response to different needs in use.

The object of the present invention is also to provide a method for fabricating a multi-layer planar coil using continuous material.

The object of the present invention is to provide a planar transformer with the above advantages.

The planar coil of the present invention includes: an inner coil stack, an outer coil stack, and a connection between the two in series, which are formed of continuous materials. The inner coil stack and the outer coil stack each include a number of planar coil layers connected in series. The winding wires in each coil layer are substantially located on the same plane. The connecting portion connects the winding wires of the inner coil stack and the outer coil stack at the same height. The inner or outer coil stack may also include an extended pad. The planar coil may also include insulating spacers between any two coil layers.

The planar coil may also include one or more coil stacks connected in series between the inner coil stack and the outer coil stack.

In an example of the invention, the coil layers in each coil stack each include windings formed in a rectangle, a polygon or a circle. In addition, in a preferred example of the present invention, the number of winding coils included in the two coil stacks is the same.

In a preferred embodiment of the present invention, the insulating spacer forms a cutout for the winding wires in the coil layer to be embedded.

In a preferred embodiment of the invention, the winding wires of each coil stack include an electrically insulating material covering the winding wire material.

The planar coil manufacturing method of the present invention includes: forming an inner coil stack in a first direction with a continuous material; the coil stack includes a plurality of planar coil layers connected in series and stacked in the first direction; extending the winding of the inner coil stack and forming an outer stack in a second direction opposite to the first direction; and the coil stack includes a plurality of planar coil layers connected in series and stacked in the second direction. In some embodiments of the present invention, the method further includes the step of forming a pad at the free end of the inner coil stack. The method may also include the step of forming a pad at the free end of the winding of the outer coil stack.

The method may further comprise the step of forming one or more coil stacks connected in series between the inner coil stack and the outer coil stack.

The method may further include the step of providing an insulating spacer between any two coil layers. The insulating spacer can form a cutout for the winding wires in the coil layer to be embedded.

In an example of the invention, the coil layers in each coil stack each include windings formed in a rectangle, a polygon or a circle. The number of windings contained in the two coil stacks may be the same. The winding wires of each coil stack may include an electrically insulating material covering the winding wire material.

A planar transformer using the planar coil of the present invention may include the planar coil, at least one second coil, and an iron core. The planar coil is stacked with the second coil, and the iron core extends in a direction perpendicular to the plane where the two coils are located, and passes through the middle of the two coils. The planar transformer can also include a metal shell covering the iron core and the coil part of the two coils. In some examples of the present invention, the second coil is the planar coil of the present invention.

The above and other objects and advantages of the present invention can be more clearly understood from the following detailed description and with reference to the accompanying drawings.

Description of drawings

FIG. 1 is a schematic structural diagram of a preferred embodiment of a planar coil of the present invention.

FIG. 2A to FIG. 2C are schematic flowcharts of a preferred embodiment of the manufacturing method of the planar coil shown in FIG. 1 .

FIG. 3 is a schematic structural diagram of a preferred embodiment of the planar transformer of the present invention.

Label description

10 inner coil stack

11, 21 pad

12, 22 winding

13, 13 winding

20 outer coil stacks

23, 23 winding

30 connection part

100 planar coil

200 second coil

300 iron core

410 upper shell

420 lower shell

detailed description

Below in conjunction with accompanying drawing and specific embodiment, the present invention will be further described:

Various embodiments of the planar coil of the present invention, its manufacturing method, and a planar transformer using the planar coil are described below with reference to the accompanying drawings. However, it should be noted that the description of the embodiments of the present invention is only used to illustrate the basic structure and possible applications of the present invention, and is not intended to limit the scope of the present invention.

The present invention proposes a novel structure of planar coils. The planar coil used in the planar transformer of the present invention can be made of a continuous material. Under the planar coil structure proposed by the present invention, the number of winding layers contained in the continuous material planar coil, and even the number of turns of each layer can be arbitrarily determined according to application requirements. The invention provides a planar coil structure which can be substantially unlimited in the number of turns and layers.

The coil of the planar transformer of the present invention is a planar coil made of continuous material. Since continuous materials can be used, simple working machines can be used to continuously mass-produce after setting parameters such as the number of layers, the number of turns, the distance between layers and the distance between turns.

FIG. 1 shows a schematic structural view of an embodiment of the planar coil of the present invention. The figure shows a planar coil 100 fabricated according to an embodiment of the present invention. The planar coil 100 comprises an inner coil stack 10 , an outer coil stack 20 , and a connecting portion 30 connecting the two in series, formed from a continuous material. The inner coil stack 10 and the outer coil stack 20 each comprise a plurality of planar coil layers connected in series. The winding wires in each coil layer are substantially located on the same plane. The connecting portion 30 connects the winding wires 12 , 22 of the inner coil stack 10 and the outer coil stack 20 at the same height. The inner coil stack 10 and the outer coil stack 20 each include an extended pad 11 , 21 . The figure shows that the two pads 11 and 21 are located on the same plane. This is because the inner coil stack 10 has the same number of coil layers as the outer coil stack 20 . The two pads 11 and 21 can extend to a plane, which is beneficial for surface adhesion processing.

Although the planar coil 100 shown in the figure includes inner and outer coil stacks, those skilled in the art can understand that there may be several coil stacks between the inner coil stack 10 and the outer coil stack 20 . That is to say, the planar coil 100 of the present invention is not limited to a double-layer structure. However, the number of coil stacks between the inner coil stack 10 and the outer coil stack 20 is preferably an even number. In this way, the pads 11 and 21 can extend out of the structure of the planar coil 100 from the same plane. Of course, the structure that the pads 11 and 21 extend out of the planar coil 100 from different planes up and down is also optional. However, depending on the design width of the coil winding material, the voltage conversion ratio of the required planar coil, the diameter of the core, and the size of the transformer in application, the number of coil stacks included should not be too large.

The number of coil layers included in the inner coil stack 10 and the outer coil stack 20 of the planar coil 100 is not limited. Depending on the thickness of the coil winding material, the required voltage conversion ratio, and the applied power, the total number of coil layers of the planar coil 100 should not be too many, so as not to affect the efficiency of the transformer. In a preferred example of the present invention, the number of coil layers contained in each layer wire stack is the same. Take the convenience of its production, not any technical restrictions.

The planar coil 100 is made of a continuous material, so that the winding wires in each coil layer in each coil stack are substantially on the same plane. That is, a planar coil layer is formed. The connecting portion 30 connects the two coil stacks on the same or substantially the same plane. In application, it is achieved by extending the connecting portion 30 from the inner coil stack 10 to the outer coil stack 20 .

In some application examples of the present invention, the planar coil 100 may further include insulating spacers between any two coil layers. If necessary, the insulating spacer can form a slit for the insertion of the winding wire of the coil layer there. The material of the insulating gasket can be any commercially available insulating material, as long as it is suitable for processing and can provide good insulating effect. Its thickness should not be too thick, but it should not be too thin, so as not to damage its insulating effect and fixing function.

The planar coil 100 of the present invention can be made of any conductive material. Suitable materials include various metals or alloys such as aluminum, copper, silver, brass, and the like. The material of the planar coil 100 may also include an insulating layer covering the winding wire. Suitable materials include any commercially available insulating material as long as it is suitable for processing and provides good insulation. Its thickness is not limited, but it is better to use a material with good ductility to avoid being affected by processing.

The winding wires of each coil layer form a rectangle, a polygon or a circle. However, from the viewpoint of ease of processing, it is more suitable for the winding to be in a circular shape. The thickness and width of each winding wire, and the maximum and minimum diameters of circles, rectangles, and polygons are not limited.

In a preferred example of the present invention, among two adjacent coil layers, at least one coil layer is provided on a base plate. The backplane is an electrically insulating sheet material.

A method of manufacturing the planar coil 100 will be described below. 2A to 2C are schematic diagrams of the manufacturing process of the planar coil 100 shown in FIG. 1 . As shown in FIG. 2A , when manufacturing the planar coil 100 , firstly, a continuous material is used to form the inner coil stack 10 in a first direction (upward direction in the figure). The inner coil stack 10 has several planar coil layers 13, 13 connected in series, stacked in the first direction. The winding wires in each coil layer are substantially on the same plane, forming a substantially flat material layer. The pad 11 extends from the windings 13 , 13 and can extend vertically to reach the plane where the pad 11 is located. Next, as shown in FIG. 2B , a connecting portion 30 is formed outwardly at the tip of the inner coil stack 10 . The connecting portion 30 extends to define the area where the outer coil stack 20 is located. Next, as shown in FIG. 2C, the winding wires 23 and 23 forming the outer coil stack 20 are extended from the connecting portion 30 to the second direction (downward direction in the figure), so as to form a coil layer stacked in the second direction. Outer coil stack 20 . The second direction is opposite to the first direction. Finally, after the necessary layers of the outer coil stack 20 are completed, the pads 21 of the outer coil stack 20 are extended to obtain the planar coil 100 as shown in FIG. 1 . In other examples of the present invention, the pads 11 and 21 are not formed when the inner coil stack 10 and the outer coil stack 20 are formed, but are formed separately after the planar coil 100 structure is completed.

After forming the planar coil 100 shown in FIG. 1 , if it is necessary to form other coil stacks, a third coil stack located outside the outer coil stack 20 can be formed in the same manner in the first direction. and so on.

Suitable methods of forming the single material planar coil 100 include any metalworking technique. Applicable techniques include known techniques such as low temperature deformation, high temperature deformation, cutting, stamping or combinations thereof. In a preferred example of the present invention, the planar coil 100 is formed by low temperature deformation. A mold is used to form a guide groove, and the material of the planar coil 100 is extruded into the groove to form continuous coil layers, and then the pads are formed by stamping. The fabrication of the planar coil 100 of the present invention can be completed.

FIG. 1 shows that the pads 11 and 21 of the planar coil 100 are located adjacently and at the same height. This design facilitates surface mount processing. But not any technical limitations.

Fig. 3 shows a schematic structural diagram of an embodiment of the planar transformer of the present invention. As shown in the figure, a planar transformer 1 using the planar coil of the present invention may include the planar coil 100 , at least one second coil 200 , and an iron core 300 . The planar coil 100 overlaps with the second coil 200 . The iron core 300 extends in a direction perpendicular to the plane where the two coils 100 , 200 are located, and passes through the middle of the two coils 100 , 200 . The planar transformer 1 may further include a metal shell, including an upper shell 410 and a lower shell 420 , covering the core 300 and the coil portions of the two coils 100 , 200 . In addition to protecting the transformer 1 , the casing also provides the function of electromagnetic wave shielding. The second coil 200 can be made of any material with good conductivity. Its structure and shape are not limited. In a preferred example of the present invention, the second coil 200 has the same or similar structure as the planar coil 100 of the present invention, but the total number of layers/coils is different to achieve the required function of the transformer. In an application, if the planar coil 100 is a primary coil, then the second coil 200 is a secondary coil. vice versa. The number of the planar coil 100 or the second coil 200, the number of layers, and the number of turns are not limited.

The material, shape, and size of the iron core 300 can be selected from known technologies according to application requirements. The material, shape and size of the upper and lower shells 410, 420 can also be selected from known technologies according to the requirements of the application. In addition, the casing is not limited to the combination of upper and lower casings. It is also possible to make the housing out of a single material or to combine more than two components. If necessary, the shell on one side can be omitted or the number of layers on one side can be increased. All of these belong to the category of known technologies, so there is no need to repeat them here.

In the structure shown in FIG. 3 , the planar coil 100 and the second coil 200 are stacked on each other. But this example is not any technical limitation. In some examples of the present invention, the second coil 200 is the planar coil of the present invention, and the layers or partial layers of the two sets of planar coils 100 and 200 are interleaved and stacked.

Claims (24)

1. a planar coil, including what formed by continuous material: inner coil storehouse, outer coil storehouse and both connecting portion of connecting；This inner coil storehouse and this outer coil storehouse respectively include some planar line ring layers being connected in series；This connecting portion connects the coiling of this inner coil storehouse and this outer coil storehouse at identical height。

2. planar coil as claimed in claim 1, it is characterised in that: inside this or outer coil storehouse also include the connection pad of an extension。

3. planar coil as claimed in claim 1 or 2, it is characterised in that: also include being positioned at the insulation spacer appointing two coil interlayer。

4. planar coil as claimed in claim 3, it is characterised in that: this insulation spacer forms a kerf, embeds for the coiling in this coil layer。

5. planar coil as claimed in claim 1 or 2, it is characterised in that: also include the one or more coil storehouses being connected in series between this inner coil storehouse and this outer coil storehouse。

6. planar coil as claimed in claim 1 or 2, it is characterised in that: the coil layer in each coil storehouse respectively includes the coiling formed with rectangle, polygon or circle。

7. planar coil as claimed in claim 1 or 2, it is characterised in that: the winding turns that this inner coil storehouse comprises with this outer coil storehouse is identical。

8. planar coil as claimed in claim 1 or 2, it is characterised in that: the coiling of each coil storehouse includes the insulating material being coated with this wire material。

9. a manufacture method for planar coil, comprises the steps:

An inner coil storehouse is formed to first direction with a continuous material；This inner coil storehouse includes some being connected in series, and to the planar line ring layer of this first direction storehouse；

Extend the coiling of this inner coil storehouse to this inner coil storehouse；

Anti-storehouse outside is formed in the second direction of this first direction in this lateral；And

This coil storehouse includes some being connected in series, and to the planar line ring layer of this second direction storehouse。

10. the manufacture method of planar coil as claimed in claim 9, it is characterised in that: the coiling free end being additionally included in this inner coil storehouse forms the step of a connection pad。

11. the manufacture method of planar coil as claimed in claim 9, it is characterised in that: the coiling free end being additionally included in this outer coil storehouse forms the step of a connection pad。

12. the manufacture method of the planar coil as described in claim 9,10 or 11, it is characterised in that: also include the step forming the one or more coil storehouses being connected in series between this inner coil storehouse and this outer coil storehouse。

13. the manufacture method of the planar coil as described in claim 9,10 or 11, it is characterised in that: it is additionally included in the step appointing two coil interlayer to provide insulation spacer。

14. the manufacture method of planar coil as claimed in claim 13, it is characterised in that: this insulation spacer forms a kerf, embeds for the coiling in this coil layer。

15. the manufacture method of the planar coil as described in claim 9,10 or 11, it is characterised in that: the coil layer in each coil storehouse respectively includes the coiling formed with rectangle, polygon or circle。

16. the manufacture method of the planar coil as described in claim 9,10 or 11, it is characterised in that: the winding turns that this inner coil storehouse comprises with this outer coil storehouse is identical。

17. the manufacture method of the planar coil as described in claim 9,10 or 11, it is characterised in that: the coiling of each coil storehouse includes the insulating material being coated with this wire material。

18. a flat surface transformer, including planar coil as claimed in claim 1 or 2, at least one second coil, and an iron core；Wherein, this planar coil is overlapped with this second coil, and this iron core extends to the direction of this two coil place plane vertical, and through the middle part of this two coil。

19. flat surface transformer as claimed in claim 18, it is characterised in that: also include a metal shell, be coated with the coiler part of this iron core and this two coil。

20. flat surface transformer as claimed in claim 18, it is characterised in that: this planar coil also includes the one or more coil storehouses being connected in series between this inner coil storehouse and this outer coil storehouse。

21. flat surface transformer as claimed in claim 18, it is characterised in that: the coil layer in each coil storehouse of this planar coil respectively includes the coiling formed with rectangle, polygon or circle。

22. flat surface transformer as claimed in claim 18, it is characterised in that: the inner coil storehouse of this planar coil is identical with the winding turns that outer coil storehouse comprises。

23. flat surface transformer as claimed in claim 18, it is characterised in that: the coiling of each coil storehouse of this planar coil includes the insulating material being coated with this wire material。

24. flat surface transformer as claimed in claim 18, it is characterised in that: this second coil is a kind of planar coil as claimed in claim 1。