JPH08130117A - Multilayer inductor - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a laminated inductor that can effectively suppress stray capacitance components, and that is also compact and low-profile. A coil pattern 2b having a magnetic path passage region in the center is arranged in a laminated body 1 in which a plurality of insulating layers are laminated, and one end of the coil pattern 2b is connected to the other end of an adjacent coil pattern 2b. In the laminated inductor formed as described above, the adjacent coil patterns 2b are arranged such that the longitudinal axes of the coil patterns 2b are different from each other and the coil patterns 2b do not substantially face each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated inductor in which a coil pattern is arranged between insulating layers forming a laminated body.

[0002]

2. Description of the Related Art Generally, a laminated inductor is composed of a laminated body made of an insulating ceramic material and a magnetic material (insulating material in a broad sense), and a coil pattern having a predetermined number of turns arranged between the layers of the laminated body. There is. One end of the coil pattern arranged between the predetermined layers is connected to the other end of the coil pattern between the adjacent insulating layers, for example, via a via-hole conductor penetrating in the thickness direction of the insulating layer. Overall, a series of predetermined coils has been achieved.

As a concrete connection method, a green sheet having a predetermined shape to be each insulating layer is prepared, and a through hole to be a via hole conductor is formed on each green sheet at a position which is one end portion of a coil pattern.

Next, a conductor film serving as a coil pattern is formed on each green sheet by Ag-based (Ag simple substance, Ag alloy), C
A conductive paste containing a u-based (Cu simple substance, Cu alloy) material, a refractory metal material or the like as a main component is applied by printing and dried to form the conductive paste. The shape has a predetermined number of turns, and one end of the conductor film is formed so as to include a through hole portion. As a result, the conductive paste is filled in the through holes.

The green sheet on which the conductor film to be the coil pattern is formed is subjected to a laminating process in consideration of the laminating order. That is, the exposed portions of the conductors (the portions exposed from the surface of the green sheet where the coil pattern is not formed) filled in the through holes are arranged so as to be connected to the other ends of the adjacent coil patterns. In the laminating process, the coil pattern may not be formed on the outermost layer portion, and a green sheet having only via-hole conductors may be laminated.

Next, the above-mentioned green sheet laminate is fired in a predetermined atmosphere. As a result, each green sheet,
Each conductor film undergoes a firing reaction to form each insulating layer and each coil pattern.

Generally, the coil pattern formed on each green sheet has substantially the same pattern, for example, a square shape, in order to minimize the formation area of the coil pattern and to enable the formation by the same printing process. Further, it was formed in a circular shape.

Therefore, the conductor portions (conductor patterns) of the adjacent coil patterns are arranged so as to be substantially overlapped with each other with the insulating layer interposed therebetween.

[0009]

In order to use the above laminated inductor in a high frequency circuit, it is important to make the self-resonant frequency of the laminated inductor sufficiently higher than the frequency of the high frequency circuit.

Generally, the self-resonance frequency f is f = 1 / (2
π (LC) ^1/2 ), in order to increase the self-resonant frequency f, if the inductor component is fixed,
It is necessary to reduce the stray capacitance which is the capacitance component C, that is, the capacitance generated between the adjacent coil patterns.

Conventionally, the thickness of the insulating layer is increased in order to reduce the capacitance between the adjacent coil patterns.

However, if the thickness of the insulating layer is increased, the thickness of the entire laminated body is increased, so that there is a problem that a compact and low-profile laminated inductor cannot be achieved.

Further, even if the insulating layer is made thicker depending on the material, it is difficult to sufficiently reduce the stray capacitance.

The present invention has been devised in view of the above-mentioned problems, and an object thereof is to provide a laminated inductor which can effectively suppress a stray capacitance component and can be made small and low in height. To do.

[0015]

According to the present invention, a coil pattern having a conductor pattern of one turn or more is arranged between each insulating layer of a laminated body in which a plurality of insulating layers are laminated, and one end of the coil pattern is arranged. In a laminated inductor formed by connecting to the other end of a coil pattern arranged between adjacent insulating layers, a conductor pattern of a coil pattern arranged between the insulating layers is substantially the same as that of a coil pattern arranged between adjacent insulating layers. It is a laminated inductor arranged so as to be positioned in a space between conductor patterns.

[0016]

According to the present invention, the coil pattern having the conductor pattern of one turn or more is laminated in the thickness direction of the laminate. At this time, the conductor patterns of the coil patterns are arranged so as to be positioned at the intervals between the conductor patterns of the adjacent coil patterns.

That is, both coil patterns are substantially the same, and in the laminated state, they do not overlap each other except for the portions where the conductor patterns of the coil patterns intersect.

As a result, the lateral spread of the laminated body can be minimized, the stray capacitance component generated between the adjacent coil patterns can be effectively suppressed, and the thickness of the insulating layer can be reduced as in the conventional case. No need to increase.

Therefore, the stray capacitance component can be effectively suppressed, the self-resonant frequency of the coil can be made sufficiently high, and a small-sized and low-profile laminated inductor in which a high-frequency circuit can be handled very easily becomes.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The laminated inductor of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view of a laminated inductor,
2 is an exploded perspective view of a laminated body of the laminated inductor, FIGS. 3 (a) and 3 (b) are plan views of a coil pattern, and FIG.
[Fig. 4] is a plan view of a partially transparent state of a laminated state.

In FIG. 1, the laminated inductor comprises a laminated body 1 formed by laminating insulating layers 1a to 1f made of an insulating material such as ceramics and a magnetic material (in the broad sense, an insulating material in the present invention), and between each layer. The coil patterns 2b to 2f are arranged mainly with a predetermined number of turns, for example, about 2 turns. The terminal electrodes 4 and 5 may be formed on the laminated body 1 as necessary.

The laminated body 1 is constituted by laminating, for example, six layers of insulating materials such as ceramics and insulating layers of magnetic material. The insulating layer 1a from the upper side is an insulating layer on the margin side on the upper side, and the coil patterns 2b to 2f constituting the actual coil are the interlayers 1b and 1c between the insulating layers 1a and 1b.
Are arranged between layers 1 ... and 1f.

For example, a layer of insulating layers 1a and 1b, that is,
At one end of the coil pattern 2b arranged on the upper surface of the insulating layer 1b, a via-hole conductor 3b penetrating in the thickness direction of the insulating layer 1b is formed. The other end is connected. Similarly, the insulating layer 1 is formed at one end of the coil pattern 2c arranged between the insulating layers 1b and 1c.
A via-hole conductor 3c is formed so as to penetrate through the thickness direction of c, whereby one end of the coil pattern 2c and the other end of the adjacent coil pattern 2d are connected. In this way, the coil patterns 2b to 2f
Are connected in series via via-hole conductors 3b to 3f.

The coil patterns 2b to 2f are Ag-based (A
g simple substance, Ag alloy), Cu-based (Cu simple substance, Cu alloy) low-resistance conductor material, and high-melting-point metal material such as W and Mo.

The via-hole conductors 3b to 3f are made of the same conductive material as the coil pattern, and the coil patterns 2b to 3f.
Dielectric layers 1b to 1e are provided at positions corresponding to one end of 2f.
Is formed in the thickness direction.

Although the terminal electrodes 4 and 5 are not described in detail in the above embodiments, for example, the via-hole conductor 3a connected to the other end of the coil pattern 2b in the thickness direction of the insulating layer 1a.
And forming via holes conductor 3f connected to one end of the coil pattern 2f in the thickness direction of the insulating layer 1f to expose both ends of the coil to the outside of the laminated body 1 and to expose the via hole conductors 3a and 3f. The terminal electrodes 4 and 5 can be formed on the portions by baking a conductive paste or the like.

In the method of manufacturing the laminated inductor having such a structure, first, an unfired green sheet to be the insulating layers 1a to 1f is prepared. Note that the green sheet is formed of a large green sheet from which a plurality of elements can be extracted in consideration of mass productivity, but in the following description, a process performed on a region where one element is taken will be described.

Next, through holes to be the via-hole conductors 3a to 3f are formed in each green sheet so as to penetrate through the green sheet.

Next, a conductive paste containing, for example, an Ag-based conductor material as a main component is printed and filled in the through holes formed in the green sheet to be the insulating layer 1a.

Further, the above-mentioned conductive paste is printed in the through holes formed in the green sheets to be the insulating layers 1b to 1f to fill the through holes, and a coil pattern of a predetermined number of turns is formed on the upper surface of each green sheet. 2b-2f
The conductor film to be formed is formed by printing the above-mentioned conductive paste. At this time, by printing so that one end portions of the coil patterns 2b to 2f are superimposed on the through holes,
You can easily fill the through holes with conductive material,
Moreover, the via hole conductors 3b to 3f and the coil pattern 2b.
A connection with one end of ~ 2f is possible.

Next, including the green sheet to be the insulating layer 1a, the green sheets to be the insulating layers 1b to 1f are laminated and pressure-bonded to be cut into a predetermined shape or a dividing groove which can be divided in the vicinity of the final step. To form.

Next, the laminated body of the green sheets is fired in a predetermined atmosphere to convert the green sheets into the insulating layers 1a-1f.
First, the conductor film is fired to the coil patterns 2b to 2f, and the conductor is fired to the via hole conductors 3a to 3f. Under the firing conditions, the peak firing temperature varies depending on the conductor material and the substrate material, and the firing atmosphere varies depending on the conductor material.
For example, when an Ag-based conductor material is used for the coil patterns 2b to 2f, the firing atmosphere is an oxidizing atmosphere or a neutral atmosphere, and the firing temperature is 960 ° C. or lower, which is the melting point of Ag. Therefore, it is necessary to select a substrate material that can be achieved by the above-mentioned firing conditions.

Thereafter, if necessary, the terminal electrodes 4 and 5 are formed by baking the conductive paste, the dividing process is performed along the dividing grooves, and the surfaces of the terminal electrodes 4 and 5 are plated as necessary. Perform processing.

Here, the characteristic of the present invention is that the adjacent coil patterns, for example, the coil patterns 2b and 2c are laminated so that the conductor pattern portions of the coil patterns 2b and 2c do not substantially overlap. It is that. Here, “substantially” means that the adjacent coil patterns 2b and 2c are connected by the via-hole conductor 3b, and the coil patterns 2b and 2c that are adjacently connected to each other have the same winding direction.
This is because the connecting portions and the intersecting portions of the coil patterns 2b and 2c cannot avoid overlapping with each other.

FIG. 3A shows a conductor film which becomes the coil pattern 2b formed on the lean sheet which becomes the insulating layer 1b, and FIG. 3B shows the conductive film which is formed on the lean sheet which becomes the insulating layer 1c. The conductor film used as the coil pattern 2b is shown.

The shapes of the coil patterns 2b and 2c shown in FIGS. 3 (a) and 3 (b) are such that the outer peripheral shape is substantially rectangular, and the axis b in the longitudinal direction of the coil pattern 2b.
x is the vertical direction in the figure, and the longitudinal axis cx of the coil pattern 2c is the horizontal direction in the figure.

In this embodiment, the adjacent coil patterns 2b and 2c have a rectangular shape and are arranged so that the conductor pattern portions of the coil patterns 2b and 2c do not substantially overlap each other. 2c are stacked and overlapped, as shown in FIG. 4, the long axis bX of the respective coil patterns 2b and the long axis cX of the coil patterns 2c.
Are arranged differently. In FIG. 4, for example, the major axes bX and cX are arranged so as to be deviated from each other by 90 °.

Since the conductor pattern of the coil pattern 2b is arranged at least in the space between the conductor patterns of the coil pattern 2c, the shapes of the coil patterns 2b and 2c can be approximated, and the coil pattern 2b can be approximated. The magnetic path portions of the patterns 2b and 2c are coil patterns 2
The inner side on the short side of the pattern on the inner peripheral side of b and 2c can be secured by a substantially square area which is one side.

Coil pattern 2b, coil pattern 2c
The overlapping portion with and is the intersection of the pattern extending in one major axis direction and the pattern extending in the other minor axis direction, and the via hole conductor 2b portion.

In order to reduce the area occupied by the two coil patterns 2b and 2c, the coil pattern 2c is provided between the coil patterns 2b as shown in FIG.
It is important that the patterns are formed so as to correspond to each other.

As a result, the stray capacitance component generated at the overlapping portion with the coil patterns 2b and 2c that are substantially adjacent to each other can be reduced, and the self-resonant frequency can be increased, and a small high-frequency can be supported. The laminated inductor can be easily achieved.

In the description of FIGS. 3 to 4, the adjacent coil patterns 2b and 2c have been described as an example, but the same applies to the relationship between the coil patterns 2c and 2d, 2d and 2e, and 2e and 2f. is there.

3 and 4 show both coil patterns 2b and 2c.
However, both coil patterns 2b and 2c may be elliptical coil patterns. In this case, the axes of the elliptical coil patterns in the major axis direction are displaced from each other. This displacement is not limited to 90 °.

Further, one coil pattern may be formed in a substantially rectangular shape and the other coil pattern may be formed in a substantially square shape. The same applies when one coil pattern is elliptical and the other coil pattern is circular.

FIGS. 5 and 6 are plan views showing adjacent coil patterns of a laminated inductor and their laminated states showing another substantial example.

In the embodiment shown in FIGS. 2 to 4, the axes of the coil patterns in the longitudinal direction (major axis direction) are displaced from each other so that the conductor pattern portions on one side of the adjacent coil patterns are separated from each other. However, the coil patterns 20b and 20c of this embodiment are intended to have a substantially square or circular shape having no longitudinal (major axis) axis.

Here, what is important is that the center points (Ob, O) of the magnetic path passage area G of both coil patterns 20b, 20c are formed.
c) are eccentric to each other, and the coil patterns 20b and 20c are arranged so as not to substantially face each other.

FIG. 5A shows a coil pattern 20b arranged on the insulating layer 1b, for example, and FIG. 5B shows a coil pattern 2 arranged on the insulating layer 1c, for example.
0c is shown. And such a coil pattern 20
FIG. 6 is a transmission plan view showing a state in which b and 20c are laminated.

As shown in FIG. 5, the coil pattern 20
Although the positions of one end side and the other end side of b and 20c are different,
The shape of the coil pattern is substantially square, and the shapes of the coil patterns are substantially the same.

However, both coil patterns 20b, 20c
As shown in FIG. 6, the planar structure in the case where the
The center point Oc of the magnetic path passage area G of the coil pattern 20c is eccentric to the diagonally right upward direction in the figure with respect to the center point Ob of the magnetic path passage area C of the coil pattern 20b, and the distance between the patterns of the coil patterns 20b is increased. The coil pattern of the coil pattern 20c is arranged in the portion, and as a whole, the overlapping portion between the coil patterns 20b and 20c is substantially only the intersection portion near the corners of the coil patterns 20b and 20c. There is.

In this way, the coil patterns 2 adjacent to each other
Even when 0b and 20c have substantially the same shape, the center positions of the magnetic path passage regions G may be eccentric to each other, and the coil patterns 20b and 20c may be arranged so as not to substantially overlap each other. Thus, it is possible to make a multilayer inductor that is small and supports a high frequency circuit with suppressed stray capacitance.

In FIGS. 5 and 6, the coil pattern 20b between the insulating layers 1a and 1b and the coil pattern 2 are shown.
The coil pattern 20c between the insulating layer 1b and the insulating layer 1c adjacent to 0b is shown and described, but the coil pattern 20c is provided between the insulating layer 1c and the insulating layer 1d, and between the insulating layer 1e and the insulating layer 1f. Arrange the same coil pattern as the pattern 20b,
A coil pattern 20c is provided between the insulating layer 1d and the insulating layer 1e.
The same coil pattern may be arranged.

In the embodiment shown in FIGS. 5 and 6, both coil patterns 20b and 20c have a square shape, but both coil patterns 20b and 20c may have a circular shape. .

Further, in the above-mentioned embodiment, the coil pattern arranged between the insulating layers has a pattern of about 2 turns, but the number of turns is not limited to 2 and may be any number of turns.

Further, the coil patterns arranged in the laminated body are connected in series to form one coil, but a plurality of coils may be formed in the same substrate.

Although the insulating layer between the coil patterns is a single layer for the sake of explanation, the insulating layer between the coil patterns is 2 depending on the material and the strength of the green sheet.
A three-layer structure may be used.

[0058]

As described above, according to both aspects of the present invention, it is possible to minimize the shape of the coil patterns that are adjacent to each other and to suppress the overlapping portion of both coil patterns.
The stray capacitance can be easily reduced, and a small-sized multilayer inductor compatible with a high frequency circuit can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view showing a cross-sectional structure of a laminated inductor of the present invention.

FIG. 2 is an exploded perspective view of a laminated body portion of the laminated inductor of the present invention.

3 (a) and 3 (b) are plan views of coil patterns having a relationship of adjacent coil patterns.

FIG. 4 is a plan view of a transparent state when the coil patterns shown in FIGS. 3A and 3B are laminated.

5 (a) and 5 (b) are plan views of coil patterns having a relationship of adjacent coil patterns used in another laminated inductor of the present invention.

FIG. 6 is a plan view of a transparent state when the coil patterns shown in FIGS. 5A and 5B are laminated.

[Explanation of symbols]

 1 ... Laminated bodies 1a to 1f ... Insulating layers 2b to 2f ... Coil patterns 20b to 20c ... Coil patterns 3a to 3f ... Via hole conductors 4, 5 ... .... Terminal electrodes

Claims (1)

[Claims] 1. A coil in which a coil pattern having a conductor pattern of one turn or more is arranged between respective insulating layers of a laminated body in which a plurality of insulating layers are laminated, and one end of the coil pattern is arranged between adjacent insulating layers. In a laminated inductor formed by connecting to the other end of the pattern, the conductor patterns of the coil patterns arranged between the insulating layers are located substantially at intervals between the conductor patterns of the coil patterns arranged between the adjacent insulating layers. A laminated inductor characterized in that it is arranged as follows.