JP2003318028A - Laminated transformer and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a primary coil and a secondary coil are apt to be different from each other in characteristics because a primary coil conductor pattern and a secondary coil conductor pattern are formed on different magnetic layers, the product is low in yield, and a magnetic coupling between the two coils is weakened due to the relative positional deviation of one of the coils from the other, so that a laminated transformer is reduced in performance of removing a common mode noise. <P>SOLUTION: The magnetic layers and a plurality of sets of the coil conductor patterns each formed on the magnetic layer are laminated, the sets of the coil conductor patterns that are each interposed between the magnetic layers are each connected together to form in the laminated layers a plurality of the coils which are spirally wound around a common winding axis as the center. An insulator possessing lower permeability than the magnetic layer is provided between the coil conductor patterns. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated transformer in which a magnetic layer and a conductor pattern are laminated, and a plurality of magnetically coupled coils are formed in the laminated body, and a manufacturing method thereof. .

[0002]

2. Description of the Related Art Generally, a transformer has a bobbin provided with a primary winding and a secondary winding, and the bobbin is covered with a magnetic core. In recent years, solid-state stacked transformers that do not use windings have been used in the field of this transformer as well, along with the demand for smaller and thinner electronic components. A magnetic layer and a conductor layer are stacked on this laminated transformer and formed so that the primary coil and the secondary coil face each other with the magnetic layer interposed between the primary coil and the secondary coil. Some are magnetically coupled.

[0003]

In such a conventional laminated transformer, since the magnetic layer is between the primary coil and the secondary coil, the magnetic flux of the coil leaks from the magnetic layer to the outside.
Since the magnetic coupling between the coils is weakened, there is a problem that common mode noise cannot be sufficiently removed when this laminated transformer is used as a common mode choke.
In order to solve such a problem, as shown in FIG. 6, a non-magnetic layer 64 is formed between the primary coil 62 and the secondary coil 63, and the primary and secondary coils of this non-magnetic layer 64 are formed. It has been practiced to provide magnetic bodies 65 connected to the magnetic layers located above and below the laminated body at positions corresponding to the central portion and the peripheral portion of the conductor pattern (Japanese Patent Application Laid-Open No. 4-206905). However,
In these laminated transformers, since the conductor pattern for the primary coil and the conductor pattern for the secondary coil are formed on different magnetic layers, the characteristics of the primary coil and the secondary coil are likely to differ from each other. The product yield was poor due to the difference in.
Also, if the relative position between these two coils is shifted,
The magnetic coupling between the coils becomes weak. Therefore, in the conventional laminated transformer, the characteristics of the primary coil and the secondary coil are different from each other, and the magnetic coupling between the coils is weakened due to the displacement of the relative position between the two coils. The ability to remove mode noise deteriorates, and it cannot be used as a common mode choke.

It is an object of the present invention to provide a laminated transformer capable of strengthening magnetic coupling between coils and improving yield by making the characteristics of a plurality of coils substantially equal to each other, and a method of manufacturing the same.

[0005]

In the laminated transformer of the present invention, a plurality of coils spirally wound around a common winding shaft are formed in the laminated body, and the plurality of coils are constituted. A plurality of sets of coil conductor patterns are formed on the same magnetic layer, and an insulating portion having a magnetic permeability lower than that of the magnetic layer is formed between the coil conductor patterns located between the magnetic layers. It solves the problem. That is, a magnetic material layer and a plurality of sets of coil conductor patterns formed on the magnetic material layer are laminated, and the coil conductor patterns between the magnetic material layers are connected to each other to form a common structure in these laminated bodies. A plurality of coils spirally wound around the winding axis are formed, and an insulating portion having a magnetic permeability lower than that of the magnetic layer is formed between the coil conductor patterns.

Further, in the method of manufacturing the laminated transformer of the present invention, the first step of forming the second magnetic layer on the entire upper surface of the first magnetic layer on which a plurality of sets of coil conductor patterns are formed. A second step of forming a loop-shaped groove in the second magnetic layer by laser processing, and a third step of forming an insulating portion having a magnetic permeability lower than that of the second magnetic layer in the loop-shaped groove Process and through-holes are formed by laser processing at the positions corresponding to the ends of the conductor patterns for each coil of the low-permeability insulator part, and for multiple sets of coils on the surface of the low-permeability insulator part. By repeating the fourth step of printing the conductor pattern, a plurality of coils spirally wound around a common winding shaft are formed in the stack.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the laminated transformer of the present invention, an insulating material portion having a magnetic permeability lower than that of the magnetic material layer is formed in a loop shape on the magnetic material layer, and the surface of the insulating material portion of the magnetic material layer is formed. A plurality of sets of coil conductors are formed. By connecting a plurality of sets of coil conductors between the magnetic layers between the sets, a plurality of coils spirally wound around a common winding axis are formed in the laminated body. At this time, the plurality of sets of coil conductor patterns are formed on the surface of the insulator portion of the magnetic layer so as to be point-symmetric with respect to the center of the surface of the magnetic layer as the origin. In this laminated transformer, a plurality of sets of coil conductor patterns forming a plurality of coils spirally wound around a common winding axis are formed on the same magnetic material layer, and the positions between the magnetic material layers are Since the insulating part having a lower magnetic permeability than the magnetic layer is formed between the coil conductor patterns, the line lengths, conductor widths, and conductor thicknesses of a plurality of coils are almost equal, and the common winding axis is centered. In addition, a plurality of coils are provided on the winding shaft portion around which the coil conductor pattern circulates without leaking magnetic flux from between the coil conductor patterns forming a plurality of coils that are spirally wound adjacent to each other in the stacking direction. Magnetic flux concentrates.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A laminated transformer and a method of manufacturing the same according to the present invention will be described below with reference to FIGS. 1 is an exploded perspective view showing a first embodiment of a laminated transformer of the present invention, and FIG. 2 is a perspective view of a first embodiment of a laminated transformer of the present invention. In FIG. 1, 11A to 11G are magnetic layers. Coil conductor patterns 12A and 13A are formed on the surface of the magnetic layer 11A. Coil conductor pattern 1
2A and the coil conductor pattern 13A are the magnetic layer 11A.
Are formed so as to be point-symmetric with respect to the origin of the center of the surface. One end of the coil conductor pattern 12A and one end of the coil conductor pattern 13A are drawn out to opposite corners of the magnetic layer 11A. The magnetic layer 11B is provided with a loop-shaped insulator portion 14 whose center coincides with the center of the surface of the magnetic layer 11B. This loop-shaped insulator 1
4 is made of a material having a lower magnetic permeability than the magnetic layer 11B, such as a non-magnetic material, a dielectric material, or a magnetic material having a low magnetic permeability.
A coil conductor pattern 1 is formed on the surface of the insulator portion 14.
2B and 13B are formed. The coil conductor pattern 12B and the coil conductor pattern 13B are formed on the magnetic layer 11
It is formed along the opposite sides so as to be point-symmetric with respect to the origin of the center of the surface of B. This coil conductor pattern 12
One end of B is connected to the other end of the coil conductor pattern 12A on the surface of the magnetic layer 11A. Further, one end of the coil conductor pattern 13B is connected to the other end of the coil conductor pattern 13A on the surface of the magnetic layer 11A. A loop-shaped insulator portion 14 is formed on the magnetic layer 11C.
The insulator portion 14 is made of a material having a lower magnetic permeability than the magnetic layer 11C. Coil conductor patterns 12C and 13C are formed on the surface of the insulator portion 14. This coil conductor pattern 12C and coil conductor pattern 1
3C is formed along a side different from the side where 12B and 13B are formed so as to be point-symmetric with respect to the origin of the surface of the magnetic layer 11C. This coil conductor pattern 1
One end of 2C is connected to the other end of the coil conductor pattern 12B, and one end of the coil conductor pattern 13C is connected to the other end of the coil conductor pattern 13B. Magnetic layer 11D
A loop-shaped insulator portion 14 is formed on the. The insulator portion 14 is formed of a material having lower magnetic permeability than the magnetic layer 11D, and has coil conductive patterns 12D and 13D on the surface.
Is formed. The coil conductor pattern 12D and the coil conductor pattern 13D are formed along the same side as the side on which 12B and 13B are formed so as to be point-symmetric with respect to the center of the surface of the magnetic layer 11D as the origin. One end of the conductor pattern 12D for coil has one conductor pattern 1 for coil.
The other end of the coil conductor pattern 13D is connected to the other end of the coil conductor pattern 13D. The loop-shaped insulator portion 14 is formed on the magnetic layer 11E with a material having a lower magnetic permeability than the magnetic layer 11E. Coil conductor patterns 12E and 13E are formed on the surface of the loop-shaped insulator portion 14. The coil conductor patterns 12E and 13E are formed along a side different from the side where the 12B and 13B are formed so as to be point-symmetric with respect to the center of the surface of the magnetic layer 11E as the origin. One end of the coil conductor pattern 12E is connected to the other end of the coil conductor pattern 12D, and one end of the coil conductor pattern 13E is connected to the other end of the coil conductor pattern 13D. The loop-shaped insulator portion 14 is formed on the magnetic layer 11F with a material having a lower magnetic permeability than the magnetic layer 11F. On the surface of the insulator portion 14, the coil conductor pattern 12 is formed.
F and the coil conductor pattern 13F are formed so as to be point-symmetric with respect to the origin of the center of the surface of the magnetic layer 11F. One end of this coil conductor pattern 12F is connected to the other end of the coil conductor pattern 12E, and the other end is led out to a corner of the magnetic layer 11F. Further, one end of the coil conductor pattern 13F is connected to the other end of the coil conductor pattern 13E, and the other end is led out to a corner portion of the magnetic layer 11F. External electrodes 21, 22, 23, and 24 are formed on the side surface and the upper and lower surfaces of the stacked body in which these are stacked and further covered with the magnetic layer 11G, as shown in FIG. And
Connect the coil conductor pattern 12A to the external electrode 21,
By connecting the coil conductor pattern 12F to the external electrode 24, a coil is formed between the external electrode 21 and the external electrode 24 by the coil conductor patterns 12A to 12F. In addition, the conductor pattern 13A for the coil is attached to the external electrode 23.
And the conductor pattern 13F for the coil is connected to the external electrode 22.
By connecting to, the coil is formed between the external electrode 22 and the external electrode 23 by the coil conductor patterns 13A to 13F. The laminated transformer formed in this way is
Two coils, which are bifilar-wound around a common winding axis parallel to the mounting surface, are formed in the laminated body, and an insulator having a magnetic permeability lower than that of the magnetic layer is provided between the coil conductor patterns forming the two coils. Parts are formed. The two bifilar wound coils form, for example, a common mode choke.

Such a laminated transformer is formed as follows. First, as shown in FIG. 3A, a plurality of sets of coil conductor patterns 32 are formed on the surface of the magnetic layer 31A.
A and 33A are printed. The magnetic layer 31A is made of ferrite. The conductor pattern for the coil is silver,
A paste-like conductor of nickel, silver palladium, copper, or the like is used, and in FIG. 3, a quarter turn is printed. Next, as shown in FIG. 3B, a magnetic layer 31B is formed on the entire surface of the magnetic layer on which the coil conductor pattern is formed. The magnetic layer 31B is formed by printing a paste of ferrite on the entire surface of the magnetic layer 31A, or by laminating a magnetic sheet on the surface of the magnetic layer 31B. Subsequently, as shown in FIG. 3C, a loop-shaped groove M is formed in the magnetic layer 31B by laser processing. The conductor patterns 32A and 33A for the coil are exposed on the bottom surface of the groove M. Further subsequently, as shown in FIG. 3D, an insulator portion 34A is formed in the loop-shaped groove. The insulator part 34A is formed by printing a paste material made of a material having a lower magnetic permeability than the magnetic material layer 31B in the groove. Subsequently, as shown in FIG. 3 (E), through holes S are formed at positions corresponding to the ends of the coil conductor patterns in the insulator portion 34A. Further, as shown in FIG. 3F, the coil conductor pattern 32B is formed on the surface of the insulator portion 34A of the magnetic layer 31B.
33B is printed. This coil conductor pattern 32B
Is arranged so that one end thereof faces the other end of the coil conductor pattern 32A. Also, the coil conductor pattern 3
3B is arranged so that one end thereof faces the other end of the coil conductor pattern 33A. A part of the insulator part 34A is
The coil conductor pattern is not printed and is left exposed. Next, as shown in FIG. 3G, a paste of ferrite is printed or a magnetic sheet is laminated on the entire surface of the magnetic layer on which the coil conductor pattern is formed. The magnetic layer 31C is formed. Subsequently, as shown in FIG. 3H, a loop-shaped groove M is formed in the magnetic layer 31C by laser processing. This groove M
The conductor patterns 32B and 33B for the coil are exposed on the bottom surface of the. Further, a part of the insulator portion 34A is exposed in a part of the groove M. Further, subsequently, as shown in FIG. 3I, a paste material made of a material having a magnetic permeability lower than that of the magnetic material layer 31C is printed in the loop-shaped groove to form an insulator portion 34.
After B is formed, as shown in FIG.
Through holes S are formed at positions corresponding to the ends of the coil conductor patterns in B. Then, following this step, printing of the coil conductor pattern, formation of the magnetic layer,
The loop-shaped groove formed by laser processing on the magnetic layer and the insulator portion formed in the groove are repeated a predetermined number of times, and finally, as shown in FIG.
As shown in (K), coil conductor patterns 32F, 3F
By printing, two coils each having a predetermined turn are formed.

FIG. 4 is an exploded perspective view showing a second embodiment of the laminated transformer of the present invention. Coil conductor patterns 42 and 43 are formed on the surface of the magnetic layer 41A.
Coil conductor pattern 42 and coil conductor pattern 43
Are formed point-symmetrically with respect to the origin of the center of the surface of the magnetic layer 41A. One end of the coil conductor pattern 42 and one end of the coil conductor pattern 43 are drawn out to the opposite side surfaces of the magnetic layer 41A. Magnetic layer 41B-41
In G, a loop-shaped insulator portion 44 whose center coincides with the center of the surface of the magnetic layer is formed. The loop-shaped insulator portion 44 is formed of a material having a lower magnetic permeability than the magnetic layer, such as a non-magnetic material, a dielectric material, or a magnetic material having a low magnetic permeability. Coil conductor patterns 42 and 43 are formed on the surface of the insulator portion 44. The coil conductor pattern 42 and the coil conductor pattern 43 are formed in an L shape so as to be point-symmetric with respect to the origin of the surface of the magnetic layer. The magnetic layer 41H has a loop-shaped insulator portion 44 whose center coincides with the center of the surface of the magnetic layer.
Conductor patterns 42 and 43 are formed on the surface of the insulator portion 44 in point symmetry with respect to the origin of the center of the surface of the magnetic layer 41H. One end of the conductor pattern for coil 42 and one end of the conductor pattern for coil are drawn out to the opposite side surfaces of the magnetic layer 41H. Then, the coil conductor patterns 42 of the magnetic layers 41A to 41H are spirally connected to form a coil. Further, the coil conductor patterns 43 of the magnetic layers 41A to 41H are spirally connected to form a coil. External electrodes 51, 52, 52 are formed on the side surface of the laminated body in which these are laminated and covered with the magnetic layer 41I, as shown in FIG.
53 and 54 are formed. Then, the coil conductor pattern 42 of the magnetic layer 41A is formed on the external electrode 52, and the magnetic layer 4 is formed.
The coil conductor pattern 43 of 1A is the external electrode 53, and the coil conductor pattern 42 of the magnetic layer 41H is the external electrode 5.
First, the coil conductor pattern 43 of the magnetic layer 41H is connected to the external electrode 54. Such a laminated transformer is
Two coils, which are bifilar-wound around a common winding axis perpendicular to the mounting surface, are formed in the laminated body, and an insulator having a magnetic permeability lower than that of the magnetic layer is provided between the coil conductor patterns forming the two coils. Parts are formed.

The embodiments of the laminated transformer of the present invention have been described above, but the present invention is not limited to these embodiments. For example, the coil conductor pattern can have various shapes such as a linear shape, an I shape, an L shape, and a U shape according to the number of turns. Moreover, the insulator part may be formed in various shapes such as a circle, a rectangle, and a square as long as it is formed in a loop shape. Further, three sets of coil conductor patterns are formed on the magnetic material layer, and the coil conductor patterns between the magnetic material layers are connected to each other, and insulation having a lower magnetic permeability than the magnetic material layer is provided between the coil conductor patterns. The body part is formed, and is trifilar wound around the common winding axis in the laminated body.
Forming one coil or forming more sets of coil conductor patterns on the magnetic layer, connecting the coil conductor patterns between the magnetic layers with each other, and placing the magnetic layer between the coil conductor patterns. Forming an insulator part with a lower magnetic permeability than
A plurality of coils wound in parallel around a common winding axis may be formed in the stack. Furthermore, a plurality of sets of the plurality of coils may be formed in the laminated body.

[0012]

As described above, in the laminated transformer of the present invention, a magnetic layer and a plurality of sets of coil conductor patterns formed on the magnetic layer are laminated to form a coil for magnetic layers. A plurality of coils spirally wound around a common winding axis are formed in the laminate by connecting the conductor patterns to each other, and a lower permeability than that of the magnetic layer is provided between the coil conductor patterns. Since the insulator part of magnetic susceptibility is formed, the line length, conductor width, and conductor thickness of the plurality of coils can be made substantially the same,
The magnetic flux of the plurality of coils can be concentrated on the winding shaft portion around which the coil conductor pattern circulates. Therefore, in the laminated transformer of the present invention, the magnetic coupling between the coils can be strengthened, and the characteristics of the plurality of coils can be made substantially equal to each other to improve the yield. Further, when the laminated transformer of the present invention is used as a common mode choke, the common mode noise removing capability can be enhanced more than the conventional one.
In addition, the method of manufacturing the laminated transformer includes a first step of forming a second magnetic layer on the entire upper surface of the first magnetic layer on which a plurality of sets of coil conductor patterns are formed, and a second magnetic layer. A second step of forming a loop-shaped groove in the layer by laser processing, a third step of forming an insulating portion having a magnetic permeability lower than that of the second magnetic layer in the loop-shaped groove, and a low magnetic permeability Forming through holes by laser processing at positions corresponding to the ends of the coil conductor patterns of each set of the insulator part, and printing a plurality of sets of coil conductor patterns on the surface of the low permeability insulator part. Since a plurality of coils spirally wound around a common winding axis are formed in the laminate by repeating the process of 4, the width, length, thickness, etc. of the plurality of sets of coil conductor patterns can be determined. It can be made almost the same, and there is no misalignment between the coils. It can also be reduced. Therefore, the method for manufacturing a laminated transformer of the present invention can provide a laminated transformer in which the magnetic coupling between the coils is strong and the characteristics of the plurality of coils are the same.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a laminated transformer of the present invention.

FIG. 2 is a perspective view of a first embodiment of the laminated transformer of the present invention.

FIG. 3 is a top view showing an embodiment of the method for manufacturing the laminated transformer of the present invention.

FIG. 4 is an exploded perspective view showing a second embodiment of the laminated transformer of the present invention.

FIG. 5 is a perspective view of a second embodiment of the laminated transformer of the present invention.

FIG. 6 is a cross-sectional view of a conventional laminated transformer.

[Explanation of symbols]

11A, 11B, 11C, 11D, 11E, 11F, 1
1G magnetic layer

Claims (7)

[Claims] 1. A magnetic material layer and a plurality of sets of coil conductor patterns formed on the magnetic material layer are laminated, and the coil conductor patterns between the magnetic material layers are connected to each other to form one of these layers. A plurality of coils spirally wound around a common winding axis are formed in the laminate, and an insulating portion having a lower magnetic permeability than the magnetic layer is formed between the coil conductor patterns. Is a laminated transformer. 2. The plurality of sets of conductor patterns for a coil,
The laminated transformer according to claim 1, wherein the laminated transformer is formed in point symmetry with the center of the surface of the magnetic layer as an origin. 3. The laminated transformer according to claim 1, wherein the low magnetic permeability insulator portion is formed in a loop shape on the magnetic layer. 4. A magnetic material layer and a plurality of sets of coil conductor patterns formed on the magnetic material layer are laminated, and the coil conductor patterns between the magnetic material layers are connected to each other to form a pair. A laminate in which a plurality of coils spirally wound around a common winding axis are formed in a laminate, and an insulating portion having a lower magnetic permeability than the magnetic layer is formed between the coil conductor patterns. In a method of manufacturing a die transformer, a first step of forming a second magnetic layer on the entire upper surface of a first magnetic layer on which a plurality of sets of coil conductor patterns are formed, and a laser on the second magnetic layer A second step of forming a loop-shaped groove by processing, a third step of forming an insulating portion having a magnetic permeability lower than that of the second magnetic layer in the loop-shaped groove, and the low magnetic permeability. The laser processing is performed at the position corresponding to the end of the conductor pattern for each coil of the insulator part of By forming a through hole and repeating a fourth step of printing a plurality of sets of coil conductor patterns on the surface of the low-permeability insulator, the laminate is spirally wound around a common winding axis. A method of manufacturing a laminated transformer having a plurality of formed coils. 5. The method of manufacturing a laminated transformer according to claim 4, wherein the formation of the second magnetic layer in the first step is performed by printing. 6. The method according to claim 4, wherein the formation of the second magnetic layer in the first step is performed by laminating magnetic sheets. 7. The loop-shaped groove in the second step is provided at a position of the second magnetic layer corresponding to a plurality of sets of coil conductor patterns provided in the first magnetic layer. The method for manufacturing a laminated transformer according to claim 4, which is characterized in that.