JPH08162328A - Layer-built coil product - Google Patents

Abstract

PURPOSE: To obtain a layer-built coil product having a pair of coils having equal impedances and difficult to generate a leakage flux. CONSTITUTION: A layer-built transformer 1 is composed of an insulator sheet 2 having coil conductors 41 -44 , 141 -144 respectively formed on the surface and protective insulator sheet 2 having lead-out via-holes 10, 20, 12 and 21. The coil conductors 41 -44 , 141 -144 form a primary coil 4 and secondary coil 14 in the form of a laminate and designed so that their effective current paths may be equal, and the coil conductors 41 -44 , 141 -144 and external electrodes are designed to be perpendicular to a mounting face of the transformer 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated coil component, and more particularly to a laminated coil component used as a transformer or a common mode choke coil.

[0002]

2. Description of the Related Art A transformer 61 shown in FIG. 10, for example, is known as a laminated coil component of this type. The transformer 61 includes coil conductors 64 ₁ , 74 ₁ , 64 ₂ , 74 ₂ ,
Insulator sheet 62 having 64 ₃ , 74 ₃ , 64 ₄ , 74 ₄ provided on the surface, insulator sheet 62 having lead conductors 67, 77, 68, 78 provided on the surface, and insulator sheet 62 serving as a protective layer It is composed of.

The coil conductors 64 ₁ to 64 ₄ are provided with via holes 80 b, 8 provided in the insulator sheet 62 in a laminated state.
The primary side coil 64 is electrically connected in series via 0c and 80d. The primary side coil 64 is electrically connected to the lead conductors 67 and 68 via the via holes 80a and 80e provided in the insulator sheet 62. On the other hand, the coil conductors 74 ₁ to 74 ₄ are electrically connected in series through the via holes 81 b, 81 c, 81 d provided in the insulator sheet 62 in the stacked state to form the secondary coil 74. The secondary coil 74 is connected to the lead conductor 77 via the via holes 81a and 81e provided in the insulator sheet 62.
Electrically connect to 78. The conductor lengths of the primary coil 64 and the secondary coil 74 are set to be equal.

By stacking these insulating sheets 62 and firing them integrally, the transformer 61 shown in FIG. 11 is obtained. The coil conductors 64 ₁ to 64 ₄ and 74 ₁ to 74 ₄ are parallel to the mounting surface 61 a of the transformer 61. External electrodes 85a, 86a, 85b, 86b are formed on the front and rear side surfaces of the transformer 61. The lead conductors 67, 68, 77, 78 are electrically connected to the external electrodes 85b, 85a, 86b, 86a, respectively.

[0005]

In this transformer 61, as shown in FIG. 12, the current flowing in the primary coil 64 in the arrow direction is the same as the current flowing in the lead conductors 67, 68. The length of the effective current path of the primary coil 64 is the length obtained by adding the coil conductors 64 ₁ to 64 ₄ . Here, the effective current path means a coil conductor that effectively acts on impedance. On the other hand, as shown in FIG. 13, a part of the current flowing in the direction of the arrow in the secondary coil 74 is opposite in direction to the current flowing in the lead conductors 77 and 78, so that the effective current of the secondary coil 74 is increased. The length of the path is the length obtained by subtracting the portion in which the two flow in opposite directions from the length obtained by adding the coil conductors 74 ₁ to 74 ₄ . Therefore, the impedance of the primary coil 64 and the impedance of the secondary coil 74 are different, and the leakage magnetic flux is easily generated. As a result,
There is a problem that the coupling coefficient between the primary coil 64 and the secondary coil 74 becomes low, and good electrical characteristics cannot be obtained.

Therefore, an object of the present invention is to provide a laminated coil component in which the impedances of a pair of coils are equal to each other and leakage flux is less likely to occur.

[0007]

In order to achieve the above object, in a laminated coil component according to the present invention, a coil conductor and an insulator are stacked to form a laminated body, and each coil conductor is electrically connected. At least a pair of formed coils have an equal effective current path, and an external electrode provided in a direction perpendicular to the mounting surface of the laminate, which is arranged perpendicular to the coil conductor and the insulator. The pair of coils are electrically connected. Here, the effective current path means a coil conductor that effectively acts on impedance.

[0008]

In the above structure, the coil conductors are arranged perpendicularly to the mounting surface of the laminated body, and the pair of coils constituted by the coil conductors have the same effective current path and are mounted on the mounting surface. On the other hand, it is electrically connected to an external electrode provided in the vertical direction. Therefore, the impedances of the pair of coils are equal to each other, and the generation of leakage magnetic flux is suppressed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the laminated coil component according to the present invention will be described below with reference to the accompanying drawings. In each of the embodiments, a case of a transformer will be described, but it goes without saying that a common mode choke coil or the like may be used. First Embodiment, FIGS. 1 to 5] As shown in FIG. 1, the multilayer transformer 1, the coil conductors 4 _1, 14 _1, 4 _2, 14 _2, 4
Insulator sheet 2 provided with ₃ , 14 ₃ , 4 ₄ , and 14 ₄ on the surface and via holes for extraction 10, 20, 11, and 21, respectively
It is composed of a protective insulating sheet 2 provided with. Each insulator sheet 2 is made of a magnetic material such as ferrite or a dielectric material such as ceramics. Coil conductors 4 ₁
4 ₄ and 14 _{1 to} 14 ₄ are formed by applying a conductive paste to the surface of the insulating sheet 2 by means of printing or the like and drying. As the conductive paste, Ag, Pd, Ni, Cu
Alternatively, metal powders of these alloys kneaded with a binder and a solvent are used.

The coil conductors 4 ₁ to 4 ₄ are provided with via holes 8 a, 8 b and 8 c provided in the insulator sheet 2 in a laminated state.
And is electrically connected in series via to form the primary coil 4. The primary coil 4 is electrically connected to the lead-out via holes 10 and 11 via a via hole 8d provided in the insulator sheet 2. On the other hand, the coil conductors 14 _{1 to} 14 ₄ are electrically connected in series through the via holes 18 a, 18 b, and 18 c provided in the insulator sheet 2 in the stacked state to form the secondary coil 14. The secondary coil 14 is drawn out via the via hole 18d provided in the insulator sheet 2 or directly.
It is electrically connected to 0 and 21. The conductor lengths of the coil conductors 4 ₁ to 4 ₄ are set to be equal to the conductor lengths of the coil conductors 14 _{1 to} 14 ₄ , respectively. After these insulating sheets 2 are stacked, they are integrally fired to form a laminated body.

As shown in FIG. 2, pull-out via holes 10, 20, 1 are formed on the front and back side surfaces of this laminated body.
1, 21 are provided, and the external electrodes 25a,
It is electrically connected to 26a, 25b, and 26b. The ends of the external electrodes 25a to 26b are folded back to the front and back surfaces of the laminated body. Then, to the mounting surface 1a of the transformer 1, the insulator sheet 2 and the coil conductors 4 ₁ to 4 _4, 14 ₁ to 1
4 ₄ are arranged vertically.

In the transformer 1 thus obtained, the coil conductors 4 ₁ to 4 ₄ and 14 _{1 to} 14 ₄ are arranged perpendicularly to the mounting surface 1 a, so that the coils 4 and 14 are directly drawn out via holes 10. , 11, 20, 21 through the external electrodes 25a, 25b, 2 in a state where the lengths of active current paths are equal.
6a and 26b are electrically connected. That is, FIG. 3 is a perspective view of the primary side coil from the direction of arrow A in FIG.
As shown in FIG. 3, there is no current flowing in the opposite direction with respect to the current flowing in the primary coil 4 in the arrow direction.
The length of the effective current path of the secondary coil 4 is determined by the coil conductors 4 ₁ to _{4 4}
It becomes the length which added. Similarly, FIG. 4 is a perspective view of the secondary side coil from the direction of arrow A in FIG. 2, but as shown in FIG. 4, it is opposite to the current flowing through the secondary side coil 14 in the direction of the arrow. Since there is no current flowing through the secondary coil 14,
The length of the effective current path is equal to the total length of the coil conductors 14 _{1 to} 14 ₄ . Since the conductor lengths of the coil conductors 4 ₁ to 4 ₄ are equal to the conductor lengths of the coil conductors 14 _{1 to} 14 ₄ , respectively, the effective current paths of the coils 4 and 14 are equal in length. Therefore,
The impedance of the primary side coil 4 and the impedance of the secondary side coil 14 become equal, and it becomes difficult to generate a leakage magnetic flux. As a result, the coupling coefficient between the primary side coil 4 and the secondary side coil 14 is increased, the transmission efficiency is good, and a transformer that does not deteriorate the transmission waveform can be obtained. FIG. 5 is an electrical equivalent circuit diagram of the transformer 1.

[Second Embodiment, FIGS. 6 to 9] As shown in FIG. 6, the laminated transformer 31 includes coil conductors 34 ₁ and 4 4.
4 _1, 34 _2, 44 _2, 34 _3, 44 _3, 34 _4, 44 ₄ an insulator sheet 32 provided on the surface, respectively, conductive lead 3
5, 45, 36, and 46 are respectively formed on the surface of the insulating sheet 32 and the insulating sheet 32 as a protective layer.

The coil conductors 34 _{1 to} 34 ₄ are provided with via holes 50b, 5 provided in the insulator sheet 32 in a laminated state.
It is electrically connected in series through 0c and 50d to form the primary coil 34. The primary coil 34 is electrically connected to the lead conductors 35 and 36 via the via holes 50a and 50e provided in the insulator sheet 32. On the other hand, the coil conductor 44 _{1-44 4,} in the laminated state via hole 51b provided in the insulating sheets 32, 51c, are electrically connected in series via 51d, to form a secondary coil 44. The secondary coil 44 has lead-out conductors 45, 46 through via holes 51a, 51e provided in the insulating sheet.
Electrically connect to. The conductor lengths of the conductors 34 _{1 to} 34 ₄ , 35 and 36 are set equal to the conductor lengths of the conductors 44 _{1 to} 44 ₄ , 45 and 46, respectively. These insulator sheets 3
After stacking the two, they are integrally fired to form a laminated body.

As shown in FIG. 7, external electrodes 55a, 56a, 5a, 5a, 5a, 5a are formed on the front and back side surfaces of this laminate, respectively.
5b and 56b are formed, and one end of each is folded back to the mounting surface 31a of the laminated body. Lead conductor 3
The end portions of 5, 36, 45 and 46 are mounted surfaces 31a.
Exposed to the external electrodes 55a, 56a, 55b, 5
6b is electrically connected to the folded portion. Then, with respect to the mounting surface 31a, the insulator sheet 32, the coil conductors 34 _{1 to} 34 ₄ , 44 _{1 to} 44 ₄ and the lead conductors 35, 3 are provided.
6, 45, 46 are arranged vertically.

In the transformer 31 thus obtained, since the coil conductors 34 _{1 to} 34 ₄ and 44 _{1 to} 44 ₄ are arranged perpendicularly to the mounting surface 31a, the coils 34 and 44 are directly drawn out to the lead conductor 35, The external electrodes 55a, 55b, 5 and
It is connected to 6a and 56b. That is, FIG. 8 corresponds to FIG.
9 is a perspective view of the primary side coil from the direction of arrow A in FIG. 8A. As shown in FIG. 8, a part of the current flowing in the primary side coil 34 in the direction of the arrow is the same as the current flowing in the lead conductor 35. Since they are opposite, the length of the active current path of the primary coil 34 is the length obtained by subtracting the portion in which the both flow in opposite directions from the primary coil 34. On the other hand, FIG. 9 is a perspective view of the secondary coil from the direction of arrow A in FIG. 7. As shown in FIG. 9, a part of the current flowing through the secondary coil 44 in the arrow direction is partially drawn out. Since the direction is opposite to that of the current flowing inside, the length of the effective current path of the secondary coil 44 is the length obtained by subtracting the portion where the two flows in the opposite direction from the secondary coil 44. Therefore, the effective current path of the primary side coil 34 and the effective current path of the secondary side coil 44 become equal, so that the impedance of the primary side coil 4 and the impedance of the secondary side coil 14 become equal, and leakage flux is generated. It gets harder. As a result, the coupling coefficient of the primary side coil 34 and the secondary side coil 44 becomes high, the transmission efficiency is good, and the transformer 31 which does not deteriorate the transmission waveform can be obtained.

[Other Embodiments] The laminated coil component according to the present invention is not limited to the above-mentioned embodiment, but can be variously modified within the scope of the invention. In particular, the number of turns and the shape of the coil are arbitrary, and various ones are selected according to the specifications. Further, the shape of the external electrode, for example, the presence or absence of folding back, the length of the external electrode, and the like are arbitrary.

[0018]

As is apparent from the above description, according to the present invention, the coil conductors are arranged perpendicularly to the mounting surface of the laminated body, and the pair of coils constituted by the coil conductors are the same. With the effective current path, it is electrically connected to the external electrodes provided in the direction perpendicular to the mounting surface, so the impedances of the pair of coils are equal and suppress the generation of leakage flux. it can. As a result, it is possible to obtain a laminated coil component which has good transmission efficiency, excellent noise elimination, and does not deteriorate the transmission waveform.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a laminated coil component according to the present invention.

FIG. 2 is a perspective view showing the outer appearance of the laminated coil component of the first embodiment.

FIG. 3 is a perspective view of a primary coil viewed from the direction of arrow A in FIG.

FIG. 4 is a perspective view of a secondary coil seen from the direction of arrow A in FIG.

5 is an electrical equivalent circuit diagram of the laminated coil component shown in FIG.

FIG. 6 is an exploded perspective view showing a second embodiment of the laminated coil component according to the present invention.

FIG. 7 is a perspective view showing the outer appearance of a laminated coil component of a second embodiment.

8 is a perspective view of the primary side coil seen from the direction of arrow A in FIG. 7.

9 is a see-through view of the secondary coil from the direction of arrow A in FIG. 7.

FIG. 10 is an exploded perspective view showing a conventional example.

FIG. 11 is a perspective view showing the appearance of a conventional example.

FIG. 12 is a perspective view of the primary coil viewed from the direction of arrow A in FIG.

FIG. 13 is a perspective view of the secondary side coil seen from the direction of arrow A in FIG. 11.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Multilayer transformer 1a ... Mounting surface 2 ... Insulator sheet 4 ... Primary side coil 4 ₁ , 4 ₂ , 4 ₃ , 4 ₄ ... Coil conductor 14 ... Secondary side coil 14 ₁ , 14 ₂ , 14 ₃ , 14 ₄ ... Coil conductors 25a, 25b, 26a, 26b ... External electrodes 31 ... Multilayer transformer 31a ... Mounting surface 32 ... Insulator sheet 34 ... Primary side coil 34 ₁ , 34 ₂ , 34 ₃ , 34 ₄ ... Coil conductor 44 ... Secondary side coils 44 ₁ , 44 ₂ , 44 ₃ , 44 ₄ ... Coil conductors 55a, 55b, 56a, 56b ... External electrodes

Claims (1)

[Claims] 1. A coil conductor and an insulator are stacked to form a laminated body, and at least a pair of coils formed by electrically connecting the coil conductors have equal effective current paths, and the coil conductor and the insulator. A laminated coil component, wherein the pair of coils are electrically connected to an external electrode provided in a direction perpendicular to a mounting surface of the laminated body that is arranged perpendicular to the.