CN105702425A - Planar coil and planar transformer - Google Patents

Abstract

The present invention provides a planar coil for use in a planar transformer and comprising, formed from a continuous material: the coil comprises a first vortex coil layer, a second vortex coil layer and N vortex coil layers which are connected in series, wherein the first vortex coil layer, the second vortex coil layer and the N vortex coil layers are overlapped. Wherein N is 0 or an even number. The connection part of any two volute coil layers is connected with the plane of the two coil layers. The first or second scroll coil layer may also include an extended contact pad. The coil of the planar transformer may further include an insulating spacer between any two of the spiral coil layers. The invention also discloses a planar transformer using the coil.

Description

Planar coils and planar transformers

technical field

The invention relates to a planar coil of a planar transformer and a planar transformer using the coil, in particular to a planar coil structure with multiple layers and multiple turns that can be made of continuous materials. The invention also discloses a planar transformer using the planar coil.

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 shape of a pad, which is used as a space between layers and as a connection electrode with the outside.

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 with 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, multi-turn planar coil structure.

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 purpose of the present invention is to provide a planar coil that can be made with continuous materials.

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

The coil of the planar transformer according to the present invention is a planar coil, and includes: a first scroll coil layer, a second scroll coil layer and N scroll coil layers connected in series. 1. The second and N scroll coil layers are stacked. Wherein, N is 0 or an even number. The scroll has an even or odd number of turns. The connecting portion of any two spiral coil layers connects the planes where the two coil layers are located. The first or second scroll coil layer may also include an extended pad. The planar coil may also include insulating spacers between any two scroll coil layers.

In an example of the present invention, the scroll includes a scroll formed in a rectangle, a polygon or a circle. In addition, in a preferred example of the present invention, each coil layer contains the same number of coils.

In a preferred example of the present invention, the insulating spacer forms a cutout for the connecting portion to be inserted into.

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. In other preferred examples, the winding wires of each coil layer include a covering material covering the winding wire material. The covering material is an electrically insulating material.

In some embodiments of the present invention, the turns of the wire form a circle.

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. In this example, the layers of the two sets of planar coils are interleaved and superimposed on each other.

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 view of an embodiment of a planar coil of the present invention.

2A to 2F are schematic diagrams of the manufacturing process of the planar coil shown in FIG. 1 .

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

Label description

1 Transformer

10 first scroll coil layer

11 Pads

14 connection part

20 second scroll coil layer

21 Pads

22 outer ring winding

23 inner ring winding

24 connection part

30 second layer coil

32 outer ring winding

33 inner ring winding

34 connection part

40 third layer coil

42 outer ring winding

43 inner ring winding

100 planar coil

200 second coil

300 iron core

410 upper shell

420 lower shell

detailed description

Various embodiments of the planar coil and the planar transformer of the present invention 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 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 a planar coil of a planar transformer. According to the present invention, planar coils for planar transformers can be fabricated from a continuous material. Under the planar coil structure proposed by the present invention, the number of winding layers and turns contained in the continuous material planar coil can be arbitrarily determined according to application requirements. The only limitation is that the number of winding layers contained in the continuous material planar coil is a positive even number. Therefore, the present invention provides a planar coil structure with substantially unlimited turns and layers.

The planar coil of the planar transformer according to 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 a planar coil of a planar transformer 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 a continuous material: the first scroll coil layer 10 located at the first upper layer in the figure, the second scroll coil layer 20 located at the bottom of the figure, namely the fourth layer, and the second scroll coil layer 20 located between the two and The second and third scroll coil layers 30 and 40 are connected in series. It is also shown in the figure that the first layer coil 10 , the second layer coil 30 , the third layer coil 40 and the fourth layer coil 20 are sequentially connected in series and stacked. The outer ends of the first scroll layer 10 and the second scroll layer 20 respectively extend to form contact pads 11 , 21 .

Although the planar coil 100 shown in the figure contains 4 coil layers, those skilled in the art can understand that as long as the number of coil layers between the first scroll coil layer 10 and the second scroll coil layer 20 is An even number satisfies the requirement that the planar coil 100 extends into the coil structure from the outside of the coil, such as the pad 11 , and extends out of the coil structure from the outside of the coil, such as the pad 21 . Therefore, the number of coil layers between the first scroll-shaped coil layer 10 and the second scroll-shaped coil layer 20 may be a positive even number such as 0, 2, 4 and so on. Of course, 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.

Likewise, according to the design of the present invention, the number of spiral windings of each coil layer is not limited. According to the description below, each layer of winding includes several turns, and extends from the outer circumference to the inner circumference or from the inner circumference to the outer circumference. Each circle substantially forms a circle. If the winding wires of two adjacent coil layers extend from the outer circumference to the inner circumference, the winding wires of the other layer extend from the inner circumference to the outer circumference. vice versa. Under this design, the number of scroll coils in each layer is not limited. However, depending on the designed 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 windings contained in each coil layer should not be too large. In a preferred example of the present invention, the number of coils contained in each coil layer 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 are substantially on the same plane. The two coil layers are connected by a connecting portion 14 . The connecting portion of any two spiral coil layers connects the planes where the two coil layers are located. In some application examples of the present invention, the planar coil 100 may further include an insulating spacer (not shown) between any two spiral coil layers. If necessary, the insulating spacer can form a cutout for the connecting portion 14 to be inserted into. 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 spiral shape. Includes scrolls formed as rectangles, polygons, or circles. However, from the viewpoint of ease of processing, the scroll shape formed in a circular shape is more suitable. The thickness and width of each winding, and the maximum and minimum diameters of the scroll are not limited. In some embodiments of the present invention, each turn of the wire forms a circle to maximize the winding angle. However, considering the characteristics of the connection part 14 connecting two adjacent planes, if it is necessary to make each coil of winding wires form a circle, all the connection parts will be located on the same projected plane position. Therefore, it is possible to consider the positions where the connection parts are arranged evenly in the application. Of course, in such an example, not all turns of the winding wire form a circle.

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 2F are schematic diagrams showing the manufacturing process of the planar coil 100 shown in FIG. 1 . As shown in FIG. 2A , when manufacturing the planar coil 100 , a continuous material is first used to form the second scroll coil layer 20 . The second scroll coil layer 20 has a pad 21 , an outer winding 22 and an inner winding 23 . Each winding wire 22, 23 is a substantially flat layer of material. The pad 21 extends from the winding wires 22 and 23 and can extend vertically to reach the plane where the pad 21 is located. Next, as shown in FIG. 2B , the inner coil winding 23 of the second scroll coil layer 20 forms the connection between the second scroll coil layer 20 (the fourth layer in structure) and the third scroll coil layer 40 . The connecting portion 24 , and then the connecting portion 24 forms the inner winding 43 of the third scroll layer 40 , and extends to form the outer winding 42 . FIG. 2C shows the third scroll coil layer 40 after completion. Next, as shown in FIG. 2D , the outer coil winding 42 of the third spiral coil layer 40 continues to extend to form the connecting portion 34 between the third spiral coil layer 40 and the second spiral coil 30 , And then form the outer winding wire 32 of the second spiral coil layer 30 , and the inner winding wire 33 thereafter. FIG. 2E shows the completed second scroll coil layer 30 . After that, as shown in FIG. 2F, the inner coil winding 33 of the second scroll coil layer 30 continues to extend to form the first scroll coil layer, that is, the first scroll coil layer 10 and the second scroll coil layer 30, and then form the first scroll coil layer 10. FIG. 1 shows the completed first scroll coil layer 10 . In this way, the fabrication of the planar coil 100 of the present invention is completed.

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 (29)

1. A planar coil of a planar transformer, comprising being formed by a continuous material: a first spiral coil layer, a second spiral coil layer and N spiral coil layers connected in series, the first, the second and the N spiral coil layers A plurality of spiral coil layers are stacked; wherein, N is 0 or a positive even number; any connecting portion of any two spiral coil layers connects the plane where the two coil layers are located. 2. The planar coil as claimed in claim 1, wherein the first or second scroll coil layer further comprises an extended pad. 3. The planar coil according to claim 1 or 2, further comprising an insulating spacer between any two spiral coil layers. 4. The planar coil as claimed in claim 3, wherein a cutout is formed on the insulating washer for the connecting portion to be inserted into. 5. The planar coil according to claim 1 or 2, characterized in that the winding wires of each coil layer comprise an electrically insulating material covering the winding wire material. 6. The planar coil according to claim 1 or 2, characterized in that: among two adjacent coil layers, at least one coil layer is provided on a bottom plate, and the bottom plate is an electrically insulating sheet material. 7. The planar coil according to claim 1 or 2, characterized in that: the scroll coil layer has a positive even number of turns or a positive odd number of windings. 8. The planar coil according to claim 1 or 2, characterized in that the number of coils contained in each coil layer is the same. 9. The planar coil as claimed in claim 1 or 2, wherein the scroll shape comprises one of a rectangle, a polygon or a circle. 10. The planar coil according to claim 1 or 2, wherein the winding wires of each coil layer form a circle. 11. The planar coil according to claim 5, wherein the number of coils contained in each coil layer is the same. 12. The planar coil as claimed in claim 5, wherein the volute comprises one of a rectangular, polygonal or circular volute. 13. The planar coil according to claim 5, wherein the winding wires of each coil layer form a circle. 14. A planar transformer, comprising the planar coil as claimed in claim 1 or 2, at least one second coil, and an iron core; wherein, the planar coil is stacked with the second coil, and the iron core is perpendicular to the two coils The direction of the plane extends and passes through the middle of the two coils. 15. The planar transformer as claimed in claim 14, further comprising a metal shell covering the iron core and the coil portions of the two coils. 16 . The planar transformer as claimed in claim 14 , wherein the winding wires of each coil layer of the planar coil include an electrical insulating material covering the winding material. 17 . 17 . The planar transformer according to claim 14 , wherein at least one of the two adjacent coil layers of the planar coil is provided on a bottom plate, and the bottom plate is an electrically insulating sheet material. 18. The planar transformer according to claim 14, wherein the number of coils contained in each coil layer of the planar coil is the same. 19. The planar transformer according to claim 14, wherein the spiral shape of the planar coil comprises one of rectangular, polygonal or circular spiral shapes. 20. The planar transformer according to claim 14, wherein the winding wires of each coil layer of the planar coil form a circle. 21. The planar transformer as claimed in claim 14, wherein the second coil is a planar coil as claimed in claim 1. 22. A planar transformer, comprising the planar coil as claimed in claim 1 or 2, at least one second coil, and an iron core; wherein, a part of each layer of the planar coil and the second coil is interpenetrated and stacked , 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. 23. The planar transformer according to claim 22, further comprising a metal shell covering the iron core and the coil portions of the two coils. 24. The planar transformer as claimed in claim 22, wherein the winding wires of each coil layer of the planar coil comprise an electrical insulating material covering the winding material. 25. The planar transformer according to claim 22, characterized in that: among the two adjacent coil layers of the planar coil, at least one coil layer is provided on a bottom plate, and the bottom plate is an electrically insulating sheet material. 26. The planar transformer according to claim 22, wherein the number of coils contained in each coil layer of the planar coil is the same. 27. The planar transformer according to claim 22, wherein the spiral shape of the planar coil comprises one of a rectangular, polygonal or circular spiral shape. 28. The planar transformer according to claim 22, wherein the winding wires of each coil layer of the planar coil form a circle. 29. The planar transformer as claimed in claim 22, wherein the second coil is a planar coil as claimed in claim 1.