JPH11144957A - Multilayered inductor array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a multilayered inductor array by which multiple coils contained in a ceramics laminate each have a comparable inductance. SOLUTION: A multilyered inductor array is comprised of a laminate 7 made of ceramic sheets 1-6 and coils 11-14 disposed in parallel in the laminate. When the distance 'd' between the ends of the laminate 7 in the direction of the length and the adjacent coils 11 and 14 is smaller than a specified value, conductive patterns 12a-12e and 13a-13e which form coils 12 and 13 and are positioned between the coil 11 and 14 are set smaller than conductive patterns 11a-11e and 14a-14e forming the coils 11 and 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multilayer inductor array, and more particularly to a multilayer inductor array used as a noise filter in a high-frequency electronic circuit or the like.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show an example of a conventional laminated inductor array of this kind. This multilayer inductor array has a chip-shaped ceramic laminate 7 formed by laminating rectangular ceramic sheets 1 to 6 made of a magnetic material.
Inside, a plurality of spiral coils 11, 12 ', 13'14
Is formed. On the main surfaces of the ceramic sheets 1 to 5, conductor patterns 11a to 11e, 12a 'to 12 constituting the coils 11, 12', 13 'and 14 are provided.
e ', 13a' to 13e 'and 14a to 14e are formed by printing or the like, respectively,
5 and the cover sheet 6 is arranged on the top and laminated,
By sequentially electrically connecting the conductor patterns via the via holes 15, the coils 11, 12 ', 13', and 14 rotating around the coil axis along the laminating direction are configured.

[0003]

By the way, in the multilayer inductor array, the conductor patterns 11a to 11e, 12a 'to 12c formed on the ceramic sheets 1 to 5 are formed.
The shapes of 12e ', 13a' to 13e ', and 14a to 14e are all the same, and the coils 11, 12'13', 1
4 have the same shape and number of turns. And
When the number of coils formed on the ceramic laminate 7 is increased or the outer shape of the ceramic laminate 7 is reduced, the distance d between the longitudinal end face of the laminate 7 and the coils 11 and 14 adjacent thereto is reduced. (See FIG. 5).

For this reason, the cross-sectional area of the magnetic path through which the magnetic lines of force of the coils 11 and 14 pass is reduced between the end coils 11 and 14 and the end face of the laminated body 7, and the inductance of the coils 11 and 14 is reduced. It becomes smaller than the inductance of the inner coils 12 ', 13'. For example, as shown in FIG. 6, when the relative magnetic permeability of the ceramic sheets 1 to 6 is 400, when the distance d is smaller than 0.5 mm, the inductance of the coils 11 and 14 on the end side decreases. Initially, compared to the inductance of the inner coils 12 ′, 13 ′, d = 0.2 mm is about 5%, d =
At 0.1 mm, the inductance is reduced by about 13%. It has been confirmed that similar results are obtained even when the relative permeability of the ceramic sheet is other than 400.

Therefore, in the conventional multilayer inductor array, there is a problem that the inductance of each coil varies depending on the position in the ceramic laminate 7.

Accordingly, an object of the present invention is to provide a multilayer inductor array in which a plurality of coils have the same inductance regardless of the position in the ceramic laminate.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention comprises a laminate in which ceramic sheets having a conductor pattern on the main surface are laminated, and the conductor pattern is provided inside the laminate. Are sequentially connected electrically, and in a multilayer inductor array formed by forming a plurality of helical coils rotating around a coil axis along a stacking direction, the multilayer body is formed such that the inductances of the plurality of coils are equal. The shape or the number of turns of the coil located inside the coil is smaller than that of the coil adjacent to the end face of the coil.

In the present invention, each coil in the laminate is
It has a shape or number of turns according to the formation position on the ceramic sheet, and the magnetic field strength of each coil is set substantially equal. Thereby, the inductance of each coil becomes equal.

In the present invention, the laminate has a rectangular parallelepiped shape, and the coils are arranged along the longitudinal direction, and the distance between the longitudinal end face of the laminate and the coil adjacent thereto is zero. It is preferably not more than 0.5 mm.
In a small inductor array in which the distance between the longitudinal end face of the ceramic laminate and the coil adjacent thereto is smaller than 0.5 mm, the inductance of each coil can be substantially equalized while avoiding an enormous shape.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the multilayer inductor array according to the present invention will be described with reference to the accompanying drawings.

(First Embodiment, see FIGS. 1 and 2) FIG.
2 and FIG. 2, the multilayer inductor array according to the first embodiment of the present invention has a structure in which each of both end faces of the ceramic laminate 7 having a rectangular parallelepiped shape and the coils 11 and 14 on the end side adjacent thereto. The distance d is set smaller than 0.5 mm. The relative magnetic permeability of the ceramic sheets 1 to 6 constituting the ceramic laminate 7 is set to 400 in this embodiment.

In this inductor array, the conductor patterns 12 constituting the inner coils 12, 13 located between the end coils 11, 14 inside the laminate 7.
The shapes of the conductor patterns 11a to 11e, 1 constituting the end-side coils 11, 14 are changed to the shapes of a to 12e and 13a to 13e.
4a to 14e. In FIGS. 1 and 2, members corresponding to those in FIGS. 4 and 5 are denoted by corresponding reference numerals, and redundant description will be omitted.

When the distance d is 0.15 mm and the coils 11 to 14 formed inside the ceramic laminate 7 have the same shape, as shown in FIG. The inductance of 11,14 is about 9.1% less than the inductance of the inner coils 12,13. Therefore, in the first embodiment, when d = 0.15 mm, the inner coils 12, 1
3 so that the internal area of the conductor patterns 12a to 3 is about 80% of the internal area of the coils 11 and 14 on the end side.
The shapes of 2e and 13a to 13e were set.

Inside the ceramic laminate 7, the conductor patterns 12 a to 12 e and 13 a to 13 c of the inner coils 12 and 13 are formed.
By setting the shape of the coil 13e small in this way, the coil 1
The cross-sectional areas of the magnetic paths through which the magnetic lines of force 1 to 14 pass are substantially equal, and the magnetic resistance (magnetic field strength) is also substantially equal.
Thereby, it is possible to obtain a laminated inductor array having a narrow deviation in which the inductances of the coils 11 to 14 are substantially equal.

FIG. 3 shows a second embodiment of the present invention. In the ceramic laminated body 7a, coils 11 to 14 are laminated in the direction of laminating the ceramic sheets 21 to 30 and the cover sheet 31. Are arranged in a zigzag pattern. Also in this case, the shapes of the coils 11 to 14 are set in the same manner as in the first embodiment, and have the same functions and effects.

The multilayer inductor array according to the present invention is not limited to the above embodiment, but can be variously modified within the scope of the invention. For example, in order to reduce the shape of the inner coils 12 and 13, not only the internal area of the coil but also the width of each conductor pattern may be reduced. Further, even though the shape is the same, the number of turns of the coil
The number of turns (the number of laminations) of 2, 13 is reduced, and each coil 1
If the strengths of the magnetic fields 1 to 14 are adjusted to be substantially equal, a desired effect can be obtained.

[0017]

As is apparent from the above description, according to the present invention, since the shape or the number of turns of the coil located inside the coil is smaller than that of the coil adjacent to the end face of the laminated body, Since the strength of the magnetic field of each coil in the body becomes substantially equal, the inductance of each coil becomes substantially equal, and a laminated inductor array having a small deviation in inductance between the coils can be obtained.

In particular, the present invention has a great advantage for a small laminated inductor array in which the distance between the longitudinal end face of the laminate and the coil adjacent thereto is 0.5 mm or less.

Further, according to the present invention, the difference between the inductances of the coils can be corrected only by changing the shape of the conductor pattern or by reducing the number of laminated ceramic sheets. No change in the manufacturing process is required, and the number of processing steps is not different from the conventional multilayer inductor array.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a multilayer inductor array according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a connection configuration of conductor patterns in the multilayer inductor array.

FIG. 3 is a schematic diagram showing a connection configuration of conductor patterns in a multilayer inductor array according to a second embodiment of the present invention.

FIG. 4 is an exploded perspective view showing a conventional multilayer inductor array.

FIG. 5 is a schematic diagram showing a connection configuration of conductor patterns in a conventional multilayer inductor array.

FIG. 6 is a graph showing a measurement result of a relationship between a distance between an end face of a ceramic laminate and a coil adjacent to the end face and a rate of decrease in inductance of the coil.

[Explanation of symbols]

 1-6, 21-31 Ceramic sheet 7, 7a Ceramic laminate 11-14 Coil 11a-11e Conductor pattern 12a-12e Conductor pattern 13a-13e Conductor pattern 14a-14e Conductor pattern 15 Via hole

Claims (2)

[Claims] 1. A laminated body in which ceramic sheets each having a conductor pattern on a main surface are laminated, and inside the laminated body,
In the multilayer inductor array, in which a plurality of helical coils that are electrically connected to the conductor pattern sequentially and rotate around a coil axis along a laminating direction are formed, the inductances of the plurality of coils are equal. The shape of the coil located inside the coil or the number of turns of the coil adjacent to the coil adjacent to the end face of the laminate is reduced. 2. The laminate has a rectangular parallelepiped shape, and the coils are arranged along a longitudinal direction of the laminate, and a distance between a longitudinal end face of the laminate and a coil adjacent thereto is 0.5 mm or less. The multilayer inductor array according to claim 1, wherein: