WO2019027265A1

WO2019027265A1 - Dual core planar transformer

Info

Publication number: WO2019027265A1
Application number: PCT/KR2018/008776
Authority: WO
Inventors: 이주열
Original assignee: 이주열
Priority date: 2017-08-03
Filing date: 2018-08-02
Publication date: 2019-02-07
Also published as: KR20190014727A

Abstract

A dual core planar transformer according to the present invention comprises: a flat plate upper core; a flat plate lower core electromagnetically coupled to the upper core; a plurality of flat plate substrates arranged between the upper core and the lower core; and a primary coil and a secondary coil which are formed in a double spiral structure on the plurality of substrates, wherein opposing surfaces of the upper core and the lower core are flat without protrusions.

Description

Dual Core Planar Transformer

The present invention relates to a planar transformer, and more particularly to a dual core planar transformer.

Conventionally, a wire wound type transformer is difficult to apply to a power supply device having a high frequency switching frequency due to an increase in loss due to a skin effect and a proximity effect occurring at a switching frequency of 100 kHz or more, A planar transformer having a high frequency band can be used in a power supply device for a high frequency band by reducing a high frequency loss, thereby achieving miniaturization and high efficiency at the same time.

The conventional planar transformer has the same characteristics as the winding transformer by implementing the primary winding and the secondary winding on the laminated PCB. However, such a planar transformer has a disadvantage that the number of stacked PCBs increases in order to arrange the number of windings .

Korean Patent Registration No. 10-0366241 relates to a thin film planar transformer and a technique for forming a plurality of layers by winding a copper plate on a PCB up and down on a PCB for miniaturization and forming the upper and lower ferrite E cores is disclosed .

However, according to the conventional technique, the bulge of the ferrite core is large at the center of the transformer, and the number of stacked PCBs increases when the number of windings of the coil is large. Also, in the PCB manufacturing process, there is a problem in that a process of manufacturing a PCB hole into which the E-core protrusion can enter due to the projections of the upper and lower ferrite E cores is required.

Therefore, even if the number of windings of the PCB plane coil increases, there is a demand for a flat transformer technology that can reduce the number of stacked PCB boards and reduce weight.

The present invention can provide a dual core planar transformer that can be downsized by reducing the number of substrates.

The present invention can provide a dual-core planar transformer that can be miniaturized without a shape in which the center portion of the ferrite E core of the transformer protrudes.

The present invention provides a dual-core planar transformer which is easy to manufacture by changing the structure of a transformer, thereby improving the economical efficiency.

A dual-core planar transformer of the present invention includes a planar upper core and a lower plate-type lower core electromagnetically coupled with the upper core, a plurality of planar substrates disposed between the upper core and the lower core, And a primary coil and a secondary coil formed in a planar double helical structure, wherein the upper core and the lower core are flat without facing each other.

The plurality of flat plate-like substrates of the present invention is characterized by including a first substrate and a second substrate on which the primary coil is formed, and the second substrate and the third substrate on which the secondary coil is formed.

A first secondary coil and a second secondary coil are formed between the second substrate and the third substrate of the present invention, and the first secondary coil and the second secondary coil are connected to each other through a winding And the directions are opposite to each other.

The first substrate of the present invention is characterized in that a pattern hole through which the primary coil is seated is formed.

The second substrate of the present invention is characterized in that pattern holes are formed on which the primary coil and the secondary coil can be placed.

The third substrate of the present invention is characterized in that pattern holes are formed in which the first and second secondary coils can be seated.

The primary coil of the present invention is connected to the primary winding terminal through a via hole.

The first secondary coil and the second secondary coil of the present invention are connected to the secondary winding terminal through a via hole.

According to the present invention, a miniaturized dual core planar transformer can be installed in high power ultra thin equipment.

According to the present invention, energy efficiency is superior to that of a conventional planar transformer.

According to the present invention, the number of substrates can be reduced compared with a conventional planar transformer, and the thickness of the transformer can be reduced.

According to the present invention, it is lighter than conventional planar transformers.

According to the present invention, the upper and lower surfaces of the ferrite core can be formed into a thin planar shape, thereby reducing the manufacturing cost.

According to the present invention, the metal thickness of the secondary winding can be reduced by improving the efficiency due to the double spiral structure.

According to the present invention, it is possible to on-board a system with less PCB stacking than a conventional planar transformer.

According to the present invention, it is possible to improve the efficiency by reducing the winding capacitance generated in the line pattern of the upper / lower layer due to the reduction of the substrate to be laminated.

1 is a view showing a configuration of a transformer according to the prior art.

2 is a perspective view schematically showing a configuration of a dual core planar transformer of the present invention.

FIG. 3 is a cross-sectional view of the dual-core planar transformer of FIG. 2 taken on line A-A '.

FIG. 4 is an exploded perspective view specifically illustrating a configuration of a dual core planar transformer of the present invention.

FIG. 5 is a view showing a core portion of a dual core planar transformer of the present invention and a shape in which a substrate is removed. FIG.

6 is a view showing a shape of a secondary coil of the dual core planar transformer of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to clarify the technical idea of the present invention. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram of a computer system according to an embodiment of the present invention; Fig.

1 is a view showing a configuration of a transformer according to the prior art. Referring to FIG. 1, a conventional transformer includes upper and

lower cores

300 and 400 having

E-shaped protrusions

301 and 401 at the center thereof, and an air gap between the protrusions according to the characteristics of the transformer. . If the

protrusions

301 and 401 having air gaps are formed as described above, it is easy to fix the coils therein, but the thickness of the transformer can not be reduced, which leads to limitations in downsizing.

FIG. 2 is a perspective view schematically showing a configuration of a dual core planar transformer of the present invention, FIG. 3 is a cross-sectional view of a dual core planar transformer of FIG. 2 taken along line AA ' Fig. 3 is an exploded perspective view specifically showing a configuration of a core plane transformer. 2 to 4, the dual core planar transformer of the present invention comprises a pair of upper and

lower cores

11 and 12 in the form of flat plates without protrusions, a substrate without through holes for penetrating the

ferrite core

21, 22, 23, and

planar coils

31, 32, 33.

A pair of ferrite and

lower cores

11 and 12 confronted by an ultra-thin PCB can induce a magnetic flux by an applied current of a plane coil without a through hole, and the first and second coils can be electromagnetically coupled have. The upper core 11 and the lower core 12 may be in the form of a flat thin plate in which the two cores do not form any projections on the surfaces facing each other. As a result, the transformer does not need to be increased in height due to the protruding portion, which makes it possible to downsize the transformer.

In the present invention, the pair of cores (11, 12) may be wrapped by a tape or the like, or may be further fixed with a fixing member.

The substrates 21 to 23 may include a first substrate 21 to a third substrate 23 which are sequentially stacked. The conventional substrate has to have a through hole to accommodate the projections provided by the pair of cores, whereas the transformer according to the present invention uses a method of not forming the protrusions on the pair of

cores

11 and 12 The effective area can be increased to the maximum, and the overall height can be reduced.

In the present invention, since the pair of

cores

11 and 12 do not have protrusions, the substrates 21 to 23 existing in the pair of

cores

11 and 12 and the flat plate- May be in the form of a substrate. Accordingly, the manufacturing process can be reduced in the process of manufacturing the transformer, and the efficiency of the fabrication can be increased.

In the present invention, holes may be formed in the respective substrates 21 to 23 for connecting the winding terminals. For example, the primary winding terminal L1 may be connected to the central portion in the longitudinal direction of the substrate 21 to 23, and the secondary winding terminal L2 may be connected to the opposite direction.

The coils 31 to 33 include a primary coil 31 and a

secondary coil

32, 33. The first and second coils 31 to 33 are formed in a double helical shape in which two plane windings are combined in an eight-letter form. The substrate is not present between the

secondary coils

32 and 33, Can exist. In the present invention, the primary and secondary coils 31 to 33 may be formed in an eight-figure shape in which two spirals are connected to reduce the number of PCB layers for arranging the windings. Further, the winding directions of the first and second coils 31 to 33 may be opposite to each other.

According to the present invention, the via holes V may be formed in the substrates 21 to 23, and the double helical coils are electrically connected to the winding terminals L1 and L2 through the via holes. That is, the primary coil 31 is connected to the primary winding terminal L1 through the via hole, and the secondary coil 32 can be connected to the secondary winding terminal L2 through the via hole. A plurality of via holes may be formed, and the first and second coils 31 to 33 may be connected through respective via holes.

In the present invention, the substrates 21 to 23 may form through holes through which the primary and secondary coils 31 to 33 may be provided. A pattern hole identical to the winding of the primary coil 31 on which the primary coil 31 can be mounted can be formed on the lower surface of the first substrate 21 and the upper surface of the second substrate 22. Holes having the same pattern as that of the windings of the

secondary coils

32 and 33, on which the

secondary coils

32 and 33 can be placed, may be formed on the lower surface of the second substrate 22. The third substrate 23 may be provided with pattern holes on which the lower surfaces of the

secondary coils

32 and 33 can be mounted. Thus, the coils are inserted into the substrate at predetermined intervals, so that the first and second coils 31 to 33 are entirely wrapped with the substrates 21 to 23, The overall height can be reduced. In the present invention, the substrates 21 to 23 are formed with pattern holes for wrapping the primary and secondary coils 31 to 33, but they may be formed of other materials that can cover the primary and secondary coils 31 to 33 The present invention can be implemented without forming pattern holes.

Since the transformer according to the present invention determines the effective area Ae of the transformer based on the inner diameters of the primary and secondary coils 31 to 33 without the metal part, the conventional transformer can reduce the area of the protrusion to the effective area of the transformer It has a wider effective area than that which is regarded as < RTI ID = 0.0 > Such a wide effective area reduces the high frequency loss of the transformer, so that it can be used in a power supply device for a high frequency band, and miniaturization and high efficiency can be achieved at the same time.

FIG. 5 is a view showing a shape of a dual core planar transformer of the present invention in which a core portion and a substrate are removed, and FIG. 6 is an enlarged view of a shape of a secondary coil of the dual core planar transformer of the present invention.

5 and 6, the primary coil 31 is formed by connecting the left side planar winding 311 and the right side planar winding 312 in a double helical shape through a connection portion 313. In addition, the

secondary coils

32 and 33 include a first secondary coil 32 and a second secondary coil 33. [

The first secondary coil 32 is formed by connecting a left side planar winding 321 and a right side planar winding 322 through a connecting portion 323. Also, the second secondary coil 33 is formed by connecting the left side planar winding and the right side planar winding through a connecting portion (not shown). At this time, since the winding directions of the first secondary coil and the second secondary coil are different from each other, the respective connecting portions can cross each other.

The primary coil 31 constitutes a double helical line in the two turns whereas the

secondary coil

32 and 33 constitutes a double helical in the eight turn planar winding, The width of the windings can be wider than that of the car coils 32, 33.

Conventionally, eight turns of plane windings are formed in four layers to form a 32-turn secondary coil. However, according to the present invention, eight turns of plane windings are formed in one layer in the form of a double helix, A total of 16 turn plane windings can be formed in the layer. Therefore, it is possible to realize 32 turns with only two layers. That is, according to the present invention, the number of turns of the

secondary coils

32 and 33 is 32 turns, which is the same as the conventional case, but can be implemented with only two layers, thereby reducing the number of substrates.

Also, although the primary coil 31 is conventionally formed of two layers of two-turn plane windings, according to the present invention, the primary coil 31 can be formed of a single layer using a double helix form.

As described above, the transformer according to the present invention can achieve the same effect as the conventional five-layer PCB substrate by using the three-layered PCB substrate by forming the primary and secondary coils 31 to 33 in a double- As a result, the transformer can be miniaturized and its efficiency can be enhanced.

The present invention has been described in detail with reference to the preferred embodiments shown in the drawings. These embodiments are to be considered as illustrative rather than limiting, and should be considered in an illustrative rather than a restrictive sense. The true scope of protection of the present invention should be determined by the technical idea of the appended claims rather than the above description. Although specific terms are used herein, they are used for the purpose of describing the concept of the present invention only and are not used to limit the scope of the present invention described in the claims or the claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It is to be understood that the equivalents include all components that are invented in order to perform the same function irrespective of the currently known equivalents as well as the equivalents to be developed in the future.

Claims

A flat plate type lower core electromagnetically coupled with the upper core and the upper core;

A plurality of flat plate-shaped substrates disposed between the upper core and the lower core; And

And a secondary coil formed on the plurality of substrates in a planar double helical structure,

Wherein the upper core and the lower core are flat on opposite sides with no protrusions.
The method according to claim 1,

Wherein the plurality of flat plate-

A first substrate and a second substrate on which the primary coil is formed; And

The second substrate and the third substrate on which the secondary coil is formed.
3. The method of claim 2,

And between the second substrate and the third substrate,

A first secondary coil and a second secondary coil are formed,

Wherein the first secondary coil and the second secondary coil have opposite winding directions to each other.
3. The method of claim 2,

Wherein the first substrate comprises:

Wherein a pattern hole is formed in which the primary coil can be seated.
3. The method of claim 2,

The second substrate may include:

Wherein a pattern hole is formed in which the primary coil and the secondary coil can be seated.
3. The method of claim 2,

Wherein the third substrate comprises:

Wherein a pattern hole is formed in which the first and second secondary coils can be seated.
3. The method of claim 2,

Wherein the primary coil comprises:

A dual core planar transformer connected to the primary winding terminal through a via hole.
The method of claim 3,

The first secondary coil and the second secondary coil are connected to each other,

A dual core planar transformer connected via a via hole to a secondary winding terminal.