CN112151238A

CN112151238A - Transformer device

Info

Publication number: CN112151238A
Application number: CN202011125776.8A
Authority: CN
Inventors: 代克; 危建; 颜佳佳
Original assignee: Nanjing Sili Microelectronics Technology Co ltd
Current assignee: Hefei silijie Semiconductor Technology Co.,Ltd.
Priority date: 2020-08-27
Filing date: 2020-10-20
Publication date: 2020-12-29
Also published as: CN213958701U

Abstract

The invention discloses a transformer, which comprises a cover plate and a magnetic core body, wherein the magnetic core body comprises a first side column, a second side column and a middle column connected with the first side column and the second side column, and a winding is wound on the middle column; the cover plate is fixed on the upper surfaces of the first side column and the second side column, wherein an air gap of the transformer is reserved in the cover plate. The transformer provided by the invention not only reduces the size, but also can realize full-automatic production and reduce the production cost.

Description

Transformer device

Technical Field

The invention relates to the field of magnetic components, in particular to a transformer.

Background

The composition of a common high-voltage transformer needs a magnetic core body, an insulating framework and an insulating adhesive tape. With the increase of switching frequency, miniaturization of magnetic elements has become a trend in the industry. In the prior art, a transformer structure directly using nickel-zinc ferrite as a framework exists, and a magnetic core of the transformer structure comprises an outer column body and an inner column body arranged inside the outer column body. The structure utilizes the insulation characteristic of the nickel core ferrite with ultrahigh resistivity, saves a winding framework and realizes the miniaturization of the high-voltage transformer. However, the technical process of the structure is complex, wires need to be wound on the inner column body, the outer column body is installed, glue is dispensed and baked, and finally the wires are electrically welded at the bottom of the outer column body. Since the wire needs external clamps to be fixed during the glue curing process, the clamps need to enter the oven together during the glue curing process (usually several hours). The mass production needs a large number of clamps, and any disturbance of the clamps easily causes the inclination of the central inner cylinder, so that the air gap for energy storage of the transformer is changed, the inductance error is increased, the yield is reduced, and the overall cost is increased.

Disclosure of Invention

Accordingly, the present invention is directed to a transformer, which can reduce the size and production cost of the transformer.

According to a first aspect of the present invention, a transformer is provided, which includes a cover plate and a magnetic core body, wherein the magnetic core body includes a first side column, a second side column, and a middle column connected to the first side column and the second side column, and a winding is wound around the middle column; the cover plate is fixed on the upper surfaces of the first side column and the second side column, wherein an air gap of the transformer is reserved in the cover plate.

Preferably, the magnetic lines of force passing through the cover plate are parallel to the plane in which the outermost winding is located.

Preferably, the cover plate is provided as a material with an internal distributed air gap.

Preferably, the cover plate is provided as a powder core material.

Preferably, the magnetic core body is i-shaped.

Preferably, the magnetic core body is provided as a nickel zinc ferrite.

Preferably, there is no air gap between the cover plate and the upper surfaces of the first and second side legs of the magnetic core body.

Preferably, the first type pins of the transformer are located on bottom surfaces of the first and second side legs, and upper surfaces of the first and second side legs are opposite to the bottom surfaces.

Preferably, the first type pins are formed by plating on the bottom surfaces of the first and second side pillars.

Preferably, bottom surfaces of the first and second side pillars have recesses formed by etching.

Preferably, the first type pins are formed by attaching a metal sheet to the concave portions.

Preferably, the first type of pins include a primary first type of pin located on a first side of the bottom surfaces of the first and second side legs and a secondary first type of pin located on a second side of the bottom surfaces of the first and second side legs, the first side being opposite the second side.

Preferably, the winding is wound on the center pillar by an automated winding.

Preferably, the winding includes a primary winding and a secondary winding, and the primary winding and the secondary winding are respectively wound on the whole center pillar from the first side pillar to the second side pillar.

Preferably, the head end and the tail end of the primary winding are spot-welded on the primary first-class pin, and the head end and the tail end of the secondary winding are spot-welded on the secondary first-class pin.

Preferably, the winding further includes a shield winding wound around the center pillar.

Preferably, the shield windings are not electrically connected.

Preferably, the shielding winding is wound outside the primary winding and the secondary winding.

Preferably, the shielding winding further comprises a second type of pin located on the upper surfaces of the first side column and the second side column, and the head end and the tail end of the shielding winding are spot-welded on the second type of pin.

Preferably, the spacing between the primary first-type pin and the secondary first-type pin is set to meet a standard electrical gap and creepage distance.

The transformer structure provided by the invention has the advantages that the first class of pins are directly formed on the bottom surface of the magnetic core body in an electroplating mode, the transformer structure is a frameless transformer structure, and the size of the transformer is reduced. In addition, the cover plate is made of the powder core material, and the primary first-class pins and the secondary first-class pins are arranged at positions, so that the transformer can realize full-automatic production, and the production cost is reduced.

Drawings

FIG. 1 is a block diagram of a transformer according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the internal magnetic field of a transformer according to an embodiment of the present invention;

FIG. 3 is a bottom pin structure of a transformer according to an embodiment of the invention;

fig. 4 is a structural diagram of a transformer according to another embodiment of the present invention.

Detailed Description

The invention will be described in more detail below with reference to the accompanying drawings. Like components are denoted by like reference numerals throughout the various figures. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale. In addition, certain well known components may not be shown. For the sake of simplicity, the structure obtained after several steps can be described in one figure. In the following description, numerous specific details of the invention, such as structure, materials, dimensions, processing techniques and techniques for each component, are set forth in order to provide a more thorough understanding of the invention. However, as will be understood by those skilled in the art, the present invention may be practiced without these specific details.

The invention provides a transformer, which comprises a cover plate and a magnetic core body, wherein the magnetic core body comprises a first side column, a second side column and a middle column connected with the first side column and the second side column, and a winding is wound on the middle column; the cover plate is fixed on the upper surfaces of the first side column and the second side column, wherein an air gap of the transformer is reserved in the cover plate.

Specifically, as shown in fig. 1, the transformer 100 includes a cover plate 101 and a core body 102, the core body includes a first side leg 110 and a second side leg 112, and a center leg 111 connected to the first side leg 110 and the second side leg 112, the center leg being wound with a winding (not shown), the cover plate 101 is fixed on the upper surfaces of the first side leg 110 and the second side leg 112, wherein an air gap of the transformer is left in the cover plate 101. No air gap is designed between the cover plate 101 and the upper surfaces of the first leg 110 and the second leg 112 of the magnetic core body 102. In the present embodiment, the core body 102 is an i-shaped core body structure, and preferably, the first side column 110 and the second side column 112 may be configured as a right quadrangular prism, and the central column 111 may be configured as a polygonal prism or a cylinder, which is not limited herein. The core body 102 is provided as a nickel zinc ferrite.

The winding comprises a primary winding and a secondary winding, the primary winding is wound on the whole middle column from the first side column 110 to the second side column 112, then the secondary winding is wound on the whole middle column from the first side column 110 to the second side column 112, and the secondary winding covers the primary winding. The primary winding and the secondary winding are electrically connected.

The cover plate 101 may be provided with an internally distributed air gap material, preferably the cover plate 101 is provided with a wick material. The powder core material is generally a powder core material with low magnetic permeability (90u-9u), such as alloy powder, metal powder, iron powder and the like.

Fig. 2 is a schematic diagram of an internal magnetic field of a transformer according to an embodiment of the present invention. Because the air gap of the transformer is left in the cover plate 101, the magnetic pressure drop uniformly falls in the cover plate, and the magnetic force lines 125 passing through the cover plate 101 are parallel to the plane where the outermost winding 103 is located, so that the component of the magnetic force lines perpendicular to the winding plane is small, mainly the horizontal component. Therefore, eddy current loss generated in the winding is less, and the ac resistance of the winding is reduced, further reducing the loss of the transformer. In addition, because the air gap is left in the cover plate 101, the air gap is not needed to be specially padded between the cover plate 101 and the magnetic core body 102, the step of padding the air gap by using an adhesive tape or an insulating material is omitted, automatic assembly production can be realized, and the cost of the small-size transformer is greatly reduced. Further, since the cover plate and the magnetic core body are tightly adhered together, the heat loss generated on the cover plate 101 is more easily dissipated to the lower surface of the magnetic core body 102 and transferred to the PCB, thereby improving the heat dissipation characteristic of the transformer.

Fig. 3 is a schematic diagram of a bottom first type pin of a transformer according to an embodiment of the invention. The first type pins of the transformer are located on the bottom surfaces of first side post 110 and second side post 112, and the top surfaces of first side post 110 and second side post 112 are opposite to the bottom surfaces. The first type of pins include primary

first type pins

121 and 122 and secondary

first type pins

123 and 124, the primary

first type pins

121 and 122 are located on a first side of the bottom surfaces of the first side post 110 and the second side post 112, and the secondary

first type pins

123 and 124 are located on a second side of the bottom surfaces of the first side post 110 and the second side post 112, the first side being opposite the second side. The winding may be wound on the center pillar 111 by an automatic winding method. Specifically, the winding includes a primary winding and a secondary winding, the primary winding is wound on the whole center pillar from the first side pillar 110 to the second side pillar 112, and then the secondary winding is wound on the whole center pillar from the first side pillar 110 to the second side pillar 112, and the secondary winding covers the primary winding. And an isolation material, such as an insulating tape and the like, is wound between the primary winding and the secondary winding. The winding head end and the winding tail end of the primary winding are respectively welded on the primary first-

type pins

121 and 122, and the winding head end and the winding tail end of the secondary winding are respectively welded on the primary first-

type pins

123 and 124.

In this embodiment, the bottom surfaces of the first side pillar 110 and the second side pillar 112 have recesses formed by etching, and the first type pins are formed by attaching metal sheets to the recesses. Of course, those skilled in the art can also form the first type pins of the transformer by directly plating metal on the bottom surfaces of the first side pillar 110 and the second side pillar 112, which is not limited herein. Wherein the metal sheet and the electroplated metal are both selected from silver materials.

In addition, the distance between the primary first-class pin and the secondary first-class pin is set to enable the primary first-class pin and the secondary first-class pin to meet the standard electric clearance and creepage distance, and a transformer with high withstand voltage can be realized by setting a proper distance C.

The transformer structure provided by the invention has the advantages that the first class of pins are directly formed on the bottom surface of the magnetic core body in an electroplating mode, the transformer structure is a frameless transformer structure, and the size of the transformer is reduced. In addition, the cover plate is made of the powder core material, and the position of the first pin of the original secondary side is arranged, so that the transformer can realize full-automatic production, and the production cost is reduced.

Fig. 4 is a structural diagram of a transformer according to another embodiment of the present invention. The transformer of the present embodiment is different from the first embodiment in that the winding further includes a shield winding 433 wound around the center leg 411. The shielding winding 433 is wound outside the primary winding (431 or 432) and the secondary winding (431 or 432), and the shielding winding 433 is not electrically connected. An isolation material, such as an insulating tape, is further wound between the primary or secondary winding (431 or 432) and the shielding winding 433. Further, the transformer further includes a second type pin 421 located on the upper surface of the first side pillar 410 and the second side pillar 412. The head end and the tail end of the shielding winding 433 are spot-welded on the second pin 421.

In the embodiment, the shielding winding is wound on the outer sides of the primary winding and the secondary winding to prevent the magnetic lines generated by the primary winding and the secondary winding from radiating outwards to generate near-field interference on peripheral electronic components or circuit boards.

While embodiments in accordance with the invention have been described above, these embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A transformer comprises a cover plate and a magnetic core body,

the magnetic core body comprises a first side column, a second side column and a middle column connected with the first side column and the second side column, and a winding is wound on the middle column;

the cover plate is fixed on the upper surfaces of the first side column and the second side column,

wherein an air gap of the transformer is left in the cover plate.

2. The transformer of claim 1, wherein the magnetic flux lines passing through the cover plate are parallel to a plane in which the outermost winding is located.

3. The transformer of claim 1, wherein the cover plate is provided as a material with an internal distributed air gap.

4. The transformer of claim 1, wherein the cover plate is provided as a powder core material.

5. The transformer of claim 1, wherein the core body is i-shaped.

6. The transformer of claim 1, wherein the core body is provided as a nickel zinc ferrite.

7. The transformer of claim 1, wherein there is no air gap between the cover plate and the upper surfaces of the first and second legs of the core body.

8. The transformer of claim 1, wherein the first type of pin of the transformer is located on a bottom surface of the first and second side legs, an upper surface of the first and second side legs being opposite the bottom surface.

9. The transformer of claim 8, wherein the first type of pin is formed by plating on bottom surfaces of the first and second side legs.

10. The transformer of claim 8, wherein bottom surfaces of the first and second side legs have an etched recess.

11. The transformer of claim 10, wherein the first type of pin is formed by affixing a metal sheet to the recess.

12. The transformer of claim 8, wherein the first type of pin comprises a primary first type of pin located on a first side of the bottom surfaces of the first and second side legs and a secondary first type of pin located on a second side of the bottom surfaces of the first and second side legs, the first side being opposite the second side.

13. The transformer of claim 1, wherein the winding is wound on the center leg by automated winding.

14. The transformer of claim 1, wherein the winding comprises a primary winding and a secondary winding, and the primary winding and the secondary winding are respectively wound on the entire center leg in a direction from the first side leg toward the second side leg.

15. The transformer of claim 8, wherein the primary winding has a leading end and a trailing end spot-welded to the primary first-type pin and the secondary winding has a leading end and a trailing end spot-welded to the secondary first-type pin.

16. The transformer of claim 14, wherein the winding further comprises a shield winding wound around the center leg.

17. The transformer of claim 16, wherein the shield windings are not electrically connected.

18. The transformer of claim 16, wherein the shield winding is wound outside of the primary winding and the secondary winding.

19. The transformer of claim 16, further comprising a second type of pin on an upper surface of the first and second side legs, the shield winding being spot welded at a leading end and a trailing end to the second type of pin.

20. The transformer of claim 12, wherein the spacing between the primary first-type leg and the secondary first-type leg is set to meet a standard electrical gap and creepage distance.