JPH11251146A - Laminating inductor and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminating inductor and method for manufacturing it wherein the number of turns of a spiral coil is increased as many as possible for larger L-value as possible. SOLUTION: A spiral coil 27 is formed inside a dielectrics chip 25, with external electrodes 26 formed on both end surfaces in longitudinal direction of the dielectrics chip 25. The spiral coil 27 is so formed that its central axis is parallel to an axis connecting both external electrodes. Since the center axis of the spiral coil 27 is parallel to the longitudinal direction of the dielectrics chip 25, the spiral coil 27 can be formed longer in central-axis direction than with a spiral coil of a laminating inductor manufactured by a conventional method. So, the number of turns of the spiral coil 27 can be increased for larger L-value of the laminating inductor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a state in which a helical coil connected to a conductor pattern is embedded in a dielectric chip by alternately printing and forming conductor patterns and dielectric layers alternately. And a method of manufacturing the same.

[0002]

2. Description of the Related Art FIG. 12 shows a conventional method of manufacturing a laminated inductor. As shown in FIG.
The dielectric layer 2 is formed by thinly applying a dielectric paste thereon, and an L-shaped conductor pattern 3 is formed thereon by printing.
The conductor pattern 3 is formed so that a part thereof is in contact with one side of the dielectric layer 2. Next, a dielectric layer 4 is formed by printing on the dielectric layer 2 so as to cover a part of the conductor pattern 3. Next, over the dielectric layer 2 and the dielectric layer 4, an L-shaped conductor pattern 5 is printed and formed on the surfaces thereof. One end of the conductor pattern 5 is connected to one end of the conductor pattern 3 exposed on the surface of the dielectric layer 2.

The same lamination procedure is repeated to laminate and form a dielectric layer and a conductor pattern. Then, a substantially U-shaped conductor pattern 8 is formed on the upper surface of the dielectric layer 6 as the uppermost layer and on the upper surface of the dielectric layer 7 formed before the dielectric layer 6. The conductor pattern 8 is formed such that a part including an end portion is in contact with one side of the dielectric layers 6 and 7. Then, by laminating the upper dielectric substrate 9, as shown in FIG. 13, a dielectric chip 10 in which a spiral coil 11 having a predetermined number of turns connected with the conductor pattern is embedded is formed. The whole is fired.

Further, external electrodes 12 are formed by printing on both end surfaces in the longitudinal direction of the dielectric chip 10. At this time, the center axis of the spiral coil 11 is arranged in a direction perpendicular to the longitudinal direction of the dielectric chip 10, and the conductor pattern 3 at the beginning of winding and the conductor pattern 8 at the end of the winding constituting the spiral coil 11 are:
The external electrodes 12 are formed so as to be in contact with the formation surfaces of the external electrodes 12 that are arranged to face each other.

[0005]

By the way, the dimensions of the multilayer inductor are determined by standards, and the external electrode 1
The direction in which 2 is formed is the longitudinal direction of the dielectric chip 10. Therefore, in the product manufactured by the above-described conventional manufacturing method of the multilayer inductor, the spiral coil 11
Is formed so that the thickness axis (transverse direction) of the dielectric chip 10 becomes the central axis, the length of the spiral coil 11 is shortened, and the number of turns of the spiral coil 11 is reduced. Therefore, the L value of the multilayer inductor becomes low.

Further, since the conductor pattern is formed by printing a conductor pace on the surface of the dielectric layer, its vertical cross-sectional shape becomes a flat rectangular shape, and by firing it, as shown in FIG. The vertical cross-sectional shape of the spiral coil 11 is a flat trapezoid whose upper part is contracted. Therefore, since the area is small and the shape is trapezoidal, the DC electric resistance increases, and the Q of the multilayer inductor increases.
There is also a problem that the value decreases. Further, when the thickness of the dielectric layer / conductor pattern is reduced in order to increase the number of turns of the coil in order to suppress the decrease in the L value as much as possible, the cross-sectional shape of the coil becomes thinner, so that the Q value is further reduced. Resulting in.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned background, and has as its object to solve the above-mentioned problems and increase the number of turns of a spiral coil as much as possible to reduce the L value. An object of the present invention is to provide a laminated inductor as large as possible and a method for manufacturing the same. Another object is to reduce the DC resistance of the coil and increase the Q value.

[0008]

In order to achieve the above-mentioned object, in a laminated inductor according to the present invention, a spiral coil having a conductor pattern connected is embedded inside a chip made of an electrical insulator. External electrodes are formed on both side surfaces in the longitudinal direction, respectively, and the external electrodes are electrically connected to the spiral coil directly or through an electrode connection pattern, and a central axis of the spiral coil is
The direction is parallel to the direction connecting the two external electrodes (claim 1). Here, the electric insulator can be realized by, for example, a dielectric or a magnetic material. As a more specific material, a glass ceramic, ferrite, or the like can be used. This applies to the following claims.

According to the dimensional standard of the laminated inductor, external electrodes are formed on both sides in the longitudinal direction of the chip. In the conventional manufacturing method, the electric insulating layers and the conductor patterns are alternately laminated, and the laminating direction is the thickness direction (the direction orthogonal to the direction connecting the external electrodes).
There was a limit to increasing the number of turns inevitably because only the process was considered. However, in the present invention, since the direction connecting the external electrodes formed on both sides of the chip and the center axis of the spiral coil are made coincident with each other, the length of the spiral coil in the winding direction can be lengthened. Even if the number of turns is increased, the number of turns can be increased, and the L value of the coil increases.

[0010] A method of manufacturing a multilayer inductor according to the present invention suitable for manufacturing the multilayer inductor according to claim 1 includes, for example, forming each of the above-mentioned respective layers on an electric insulating layer on which a plurality of lower band-shaped conductor patterns are formed. A step of printing and forming an electrical insulating layer having holes formed at positions opposed to both ends of the lower band-shaped conductor pattern, and a step of printing and forming columnar conductor patterns at positions opposed to both ends of each of the lower band-shaped conductor patterns. Repeat in the following order. Then, by repeating the two steps a predetermined number of times, a plurality of electric insulating layers in which the columnar conductor patterns are inserted are laminated in the hole, and the uppermost electric insulating layer of the plurality of electric insulating layers is formed. On the upper surface, by performing a print forming step of the upper band-shaped conductor pattern so as to connect the predetermined columnar conductor patterns to each other, the above-described upper / lower band-shaped conductor pattern and the columnar conductor pattern are connected to form a spiral coil. I do.
Further, an insulating member is laminated on a surface of the electric insulating layer on which the upper strip-shaped conductor pattern is formed, and a chip in which the spiral coil is embedded is formed. Next, the spiral coil is formed so that the central axis direction thereof coincides with the longitudinal direction of the chip, and external electrodes that are electrically connected to the upper band-shaped conductor pattern are formed at both ends in the longitudinal direction of the chip. did. (Claim 2). That is, the lower band-shaped conductor pattern, the lower band-shaped conductor pattern, and the columnar conductor pattern constitute the conductor pattern according to the first aspect.

Preferably, the cross-sectional shape of the columnar conductor pattern formed inside the hole is circular. Since the cross-sectional shape of at least a part of the spiral coil is a circle having a small DC resistance, the Q value of the manufactured laminated inductor increases. The circular shape is most preferably a perfect circle, but an elliptical shape and a similar shape are also included in the circular shape in the present invention.

In another manufacturing method, a conductor pattern and an electric insulating layer are alternately formed by printing and laminated sequentially to form an intermediate product in which a spiral coil connected to the conductor pattern is embedded. Then, cutting at a predetermined position of the intermediate product, when forming a chip having the spiral coil inside, so that the longitudinal direction of the chip is in the direction of the central axis of the spiral coil, the dielectric External electrode is formed on both end surfaces in the longitudinal direction of the body chip, and an electrode connection pattern for connecting both ends of the spiral coil and the external conductor is formed at a predetermined timing after the spiral coil is formed. (Claim 4).
Here, it is simple and preferable to form the electrode connection pattern outside the chip as in the embodiment. In this case, the predetermined timing is after cutting to form a chip, before forming an external electrode, or after forming an external electrode. Inevitably, both ends of the spiral coil are cut at positions where they are exposed on the outer surface of the chip. In the case where the electrode connection pattern is formed inside the chip, the direction toward the external electrode is the direction of lamination of the electric insulating layer, and therefore, for example, the step of forming a columnar conductor pattern according to claim 2 is used. Can be formed.

[0013]

1 and 2 show a first embodiment of a method of manufacturing a laminated inductor according to the present invention. FIG. 1 is a plan view, and FIG.
It is sectional drawing which shows the left half of FIG.

In this embodiment, first, as a ceramic material for forming a dielectric layer serving as an electrical insulating layer, a dielectric material added with ferrite or glass and sintered at a low temperature is used.
As an example, a dielectric material (glass-based ceramic material) in which borosilicate glass and alumina are mixed at a volume ratio of 70:30 is used, and as a vehicle, ethyl cellulose, terpinel, dispersant, plasticizer, and the like are used. The mixture of the agents is blended and mixed to form a printing paste. The conductor paste used for printing and forming the conductor pattern (pattern element) uses silver, which is a mixture of silver and the same vehicle as the dielectric material. As a binder to be used, PVB, methyl cellulose or the like is used other than ethyl cellulose.
Note that silver palladium can be used instead of silver.
Further, the dispersant and the plasticizer are taken into consideration in consideration of improvement in printability and handling during production.

A multilayer inductor is manufactured by sequentially printing the various pastes in a predetermined pattern.
Specifically, first, as shown in FIGS. 1A and 2A, a paste of the ceramic (dielectric material) is printed to a predetermined thickness to form a dielectric layer 15 serving as an electrical insulating layer. .

As shown in FIGS. 1B and 2B, lower conductive strips 16a to 16d are formed on the upper surface of the dielectric layer 15 by printing. In the present embodiment, the lower band-shaped conductor patterns 16a to 16d are each formed into an elongated one.
The lower band-shaped conductor patterns 16a to 16d are formed so as to form a rectangular pattern.
5 is formed so as to be parallel to the short side and at equal intervals. At this time, the lower band-shaped conductor pattern 1 is repeated a plurality of times.
By printing 6a to 16d, the film thickness increases,
DC resistance can be reduced.

Next, the lower band-shaped conductor patterns 16a to 16a-1
A ceramic material is printed on the upper surface of the dielectric layer 15 on which 6d is formed to form the dielectric layer 17 (FIGS. 1C and 2).
(C)). At this time, the dielectric layer 17 includes, at positions corresponding to both ends of the lower band-shaped conductor patterns 16a to 16d,
Cylindrical holes 18a to 18h penetrating in the thickness direction are provided. Then, a conductor paste is printed inside the holes 18a to 18h to form columnar conductor patterns (vias) 19a to 19h.
form h. Such columnar conductor patterns 19a to 19h
Is formed along the shape of the holes 18a to 18h, and thus has a columnar shape (FIGS. 1D and 2D). Thereby, the columnar conductor patterns 19a, 19b are electrically connected to both ends of the lower band-shaped conductor pattern 16a, and the columnar conductor patterns 19c, 1 are connected to both ends of the lower band-shaped conductor pattern 16b.
9d is electrically connected to the lower strip-shaped conductor pattern 16c.
The columnar conductor patterns 19e and 19f are electrically connected to both ends, and the columnar conductor patterns 19g and 19h are electrically connected to both ends of the lower band-shaped conductor pattern 16d.

Then, a step of printing the above-described dielectric layer having holes (FIGS. 1C and 2C) and a step of printing and forming a columnar conductor pattern in the holes (FIG. 1).
(D) and FIG. 2 (D)) are repeated. Thereby, as shown in FIGS. 2C and 2D, the columnar conductor patterns 19b 'having a columnar shape are sequentially formed on the existing columnar conductor patterns 19b. Thereby, the columnar conductor extends in the laminating direction (thickness direction).

In this manner, the step of printing the dielectric layer having the hole and the step of printing and forming the columnar conductor pattern in the hole are repeated a predetermined number of times, whereby the uppermost dielectric layer (also the hole) is formed. 1) (see FIG. 1).
(E)). The columnar conductor patterns 19 ″ a to 19 ″ h formed so as to be exposed on the surface of the dielectric layer 20 are in the same straight line as the columnar conductor patterns 19a to 19h connected to the upper surfaces of the lower band-shaped conductor patterns 16a to 16h, respectively. And is in a conductive state via each of the columnar conductor patterns formed in the intermediate layer (not shown).

Next, upper strip-shaped conductor patterns 22b to 22d are formed on the upper surface of the dielectric layer 20 so as to connect the columnar conductor patterns formed at oblique positions.
That is, the upper band-shaped conductor pattern 22b is formed by printing so as to connect the columnar conductor patterns 19 "b and 19" c, and the upper band-shaped conductor pattern 22c is formed so as to connect the columnar conductor patterns 19 "d and 19" e. The upper band-shaped conductor pattern 22d is formed by printing so as to connect the columnar conductor patterns 19 "f, 19" g. Further, an upper band-shaped conductor pattern 22a is formed by printing so as to connect the column-shaped conductor pattern 19 "a and the midpoint of the short side of the dielectric layer 20, and the column-shaped conductor pattern 19" h and the short side of the dielectric layer 20 are formed. The upper band-shaped conductor pattern 22e is printed and formed so as to connect the points. The upper band-shaped conductor pattern 22a
In printing and forming ２２22e, it is possible to increase the thickness by printing a plurality of times, thereby reducing the DC resistance.

As a result, the upper strip-shaped conductor patterns 22a and 22e located on both sides in the longitudinal direction of the dielectric layer 20 are formed into one continuous spiral coil by each of the columnar conductor patterns, the lower strip-shaped conductor patterns, and the upper strip-shaped conductor patterns. And the center axis of the helical coil is in a direction parallel to the long side of the dielectric layer 20.

Then, an upper dielectric layer (substrate) 24 having a predetermined thickness is laminated by printing a paste-like dielectric material (ceramic) a plurality of times on the upper surface of the dielectric layer 20 (FIG. 1F). )). Actually, in order to simultaneously form a plurality of the above-mentioned steps on a large substrate, the chips are cut and degreased and fired.

Then, as shown in FIG. 3, external conductors are formed on both ends of the dielectric chip 25 in the longitudinal direction by baking and plating, thereby forming external electrodes 26 respectively. At this time, the upper strip-shaped conductor patterns 22a and 22e located at both ends are connected to the external electrodes 26. By the above method, a multilayer inductor in which the spiral coil 27 is arranged inside the dielectric chip 25 is manufactured.

In the multilayer inductor manufactured by the manufacturing method according to the present embodiment, the center axis of the spiral coil is in a direction parallel to the axis connecting the external electrodes 26. That is, since the direction of the center axis of the spiral coil is the longitudinal direction of the dielectric chip 25, such a spiral coil is more axially centered than the spiral coil of the multilayer inductor manufactured by the conventional manufacturing method. It can be formed long. Therefore, since the number of turns of the spiral coil manufactured by the manufacturing method according to the present embodiment can be increased, the L value of the multilayer inductor can be increased.

Further, in this embodiment, since the columnar conductor pattern constituting the spiral coil is cylindrical, the cross-sectional shape of each part of the spiral coil is circular, thereby reducing the DC resistance and increasing the Q value of the laminated inductor. be able to.

In the above description, first, the step of forming the dielectric layer 17 with holes (FIG. 1C, FIG.
(C)), a step of filling the hole with a conductive paste to form a columnar conductive pattern (FIG. 1 (D), FIG.
(D)) is performed, but the present invention is not limited to this. First, a step of printing a conductor paste on a predetermined pattern to form a columnar conductor pattern is performed, and then the columnar conductor pattern is formed. The step of forming a dielectric layer by printing a dielectric paste on the unformed region may be performed. That is, either of the printing step of the dielectric layer and the printing step of the columnar conductor pattern may be performed first.

FIG. 4 shows a main part of a second embodiment of the method for manufacturing a laminated inductor according to the present invention. In the multilayer inductor manufactured by the manufacturing method according to the present embodiment,
Compared with the first embodiment, the number of turns of the spiral coil is increased, so that the L value of the product can be further increased.

That is, the lower strip-shaped conductor patterns 31a to 31g are formed on the upper surface of the lower dielectric layer 30 shown in FIG. Such lower band-shaped conductor patterns 31a to 31g
Is formed so as to be parallel to the short side of the lower dielectric layer 30. And the lower strip-shaped conductor patterns 31a to 31g are:
Long patterns (31a, 31c, 31e, 31g)
Short patterns (31b, 31d, 31f) are formed so as to be alternately arranged (FIG. (B)).

Next, a dielectric layer 32 is formed on the upper surface of the lower dielectric layer 30. At this time, the hole 33 is formed in the dielectric layer 32 at the same position as both ends of the lower strip-shaped conductor patterns 31a to 31g.
a to 33n are provided (FIG. 2C). And
The inside of the holes 33a to 33n is filled with a conductive paste to provide columnar conductive patterns 34a to 34n (FIG. (D)).

The same steps (steps shown in FIGS. 3C and 3D) are repeated a predetermined number of times to form up to the uppermost dielectric layer 35, which is formed on the dielectric layer 35. Upper strip-shaped conductor patterns 36b-36 connecting the columnar conductor patterns 34'b-34'm at oblique positions.
m, columnar conductor patterns 34'a, 34'n at both ends,
Upper strip-shaped conductor patterns 36a and 36h connecting the midpoint of the short side of the dielectric layer 35 are formed (FIG. 10E). Thereby, a spiral coil is formed.

Then, a dielectric ceramic is printed on the upper surface of the dielectric layer 35 a plurality of times, so that the upper dielectric layer 37 is printed.
Is formed, and finally the whole is fired to form a dielectric chip, and external electrodes are formed on both end surfaces in the longitudinal direction of the dielectric chip to complete a multilayer inductor.

The spiral coil formed in the present embodiment has a larger number of turns than the spiral coil formed in the first embodiment. Therefore, L of the multilayer inductor
The value can be larger than that in the first embodiment.

FIG. 5 shows a third embodiment of the method for manufacturing a laminated inductor according to the present invention. In the product manufactured according to the present embodiment, the cross-sectional shape of the columnar conductor pattern constituting the spiral coil is circular, and the cross-sectional area of the conductor pattern is larger than that of the first embodiment. .

On the upper surface of the dielectric layer 40 shown in FIG.
The wide band-shaped lower band-shaped conductor patterns 41a and 41b are
The printing is performed a plurality of times in parallel with the main body to a predetermined thickness ((B) in the same figure). Next, the lower band-shaped conductor patterns 41a, 41
The dielectric paste is printed in a pattern shape such that the holes 43a to 43d are located at positions corresponding to both ends of b, thereby forming the dielectric layer 40 (FIG. 3C). The diameter of the holes 43a to 43d formed at this time is set to be larger than the diameter of the holes in each of the above-described embodiments. Then, such a hole 43a
To 43d are filled with a conductive paste to form columnar conductive patterns 44a to 44d having a large diameter.
Is formed (FIG. 2D).

The upper band-shaped conductor patterns 46a to 46c are formed by printing on the upper surface of the uppermost dielectric layer 45 obtained by repeatedly performing the above-described dielectric layer forming step and columnar conductor pattern forming step. One continuous spiral coil is formed by the upper and lower strip-shaped conductor patterns and the columnar conductor patterns (FIG. (E)). Thereafter, though not shown, the dielectric chip is fired to form external electrodes, thereby manufacturing a multilayer inductor.

As is apparent from a comparison between FIG. 5 and FIG. 1, the basic steps are the same, but in this embodiment, the width of each pattern and the diameter of the pattern are increased.
Since the sectional area of each part of the manufactured coil can be increased, the DC resistance can be further reduced, and a large Q value can be obtained.

6 to 9 show a fourth embodiment of the method for manufacturing a laminated inductor according to the present invention. In this embodiment, similarly to the conventional manufacturing method of the multilayer inductor, by alternately printing and forming the dielectric layer and the conductor pattern,
The common point is that the helical coil is arranged inside the dielectric chip.However, by switching the concept from the conventional one at the time of cutting, the center axis of the helical coil in the final laminated inductor is shifted to the outside. The direction is to connect the electrodes.

That is, as shown in FIG. 6, a dielectric layer 51 is formed by printing on the surface of the lower dielectric substrate 50 (FIG. 6A), and a substantially C-shaped conductor is formed on the surface of the dielectric layer 51. A pattern 52 is formed (FIG. 2B). The conductive pattern 52 is formed by printing so that one end thereof is in contact with one side of the dielectric layer 51.

Next, the step shown in FIG. 3C is performed to form a spiral coil. That is, the conductor pattern 52
The dielectric layer 53 is formed such that a portion of the dielectric layer 53 is exposed (C-
). Then, a substantially L-shaped conductor pattern 54 is formed so as to be connected to the exposed end of the conductor pattern 52 (C-). Next, the dielectric layer 55 is formed by printing so that the tip side of the conductor pattern 54 is exposed (C-),
A conductor pattern 56 connected to the exposed end of the conductor pattern 54 is printed on the upper surface of the dielectric layer 55. By performing this step, a coil for one turn is formed.

After that, the above-described process of FIG. (C) is repeated a predetermined number of times, and when a predetermined number of turns is obtained, finally, as shown in FIG. After performing the same steps as in (1), a conductor pattern 57 connected to the tip of the exposed conductor pattern 54 "is formed as shown in FIG. 4D. This conductor pattern 57 is formed on the dielectric layer 55". Formed on the dielectric layer 5
5 ". Finally, the dielectric paste is printed a predetermined number of times to form the upper dielectric substrate 5".
8 are laminated (FIG. 10E). The steps up to this point can be realized by the same steps as the conventional one shown in FIG. 12, although the specific pattern shape is different.

In practice, since a large number of dielectric chips each having a spiral coil disposed therein are formed at a time, a dielectric material having an area larger than the area of the dielectric layer constituting the dielectric chips is required. The above process is performed at each position on the substrate, and the intermediate product 6 formed after the step of FIG.
0 has a plurality of spiral coils 6 inside as shown in FIG.
1 are arranged (three spiral coils are shown for the sake of convenience in the illustrated example, but of course, a large number of them are formed in a grid).

Then, by cutting the intermediate product 60 at a predetermined position, as shown in FIG. 8A, a dielectric chip 62 in which one spiral coil 61 is disposed is formed. At this time, in the present embodiment, the longitudinal direction of the formed dielectric chip 62 matches the spiral coil 61 arranged inside.
Cut so that it matches the direction of the center axis of. That is, in the related art, the laminating direction of the dielectric layer and the like in the manufacturing process is the thickness direction of the laminated inductor as it is, but in the present embodiment, the laminating direction and the thickness direction are turned down by 90 degrees after cutting. They are orthogonal. There is a point in this cutting method and in rotating after cutting.

Further, external electrodes electrically connected to the helical coil 61 are formed on both end surfaces in the longitudinal direction of the dielectric chip 62 according to the dimensional specification of the laminated inductor. Conductive patterns 52, 5
7 is not in contact with the surface of the dielectric chip 62 in the longitudinal direction. Therefore, on the surface of the dielectric chip 62, an electrode connection pattern 65 connecting the ends of the conductor patterns 52, 57 and both longitudinal edges of the dielectric chip 62 is formed (FIG. 8B). The reason why the connection pattern is formed on the surface in order to simplify the manufacturing process is, of course, to form a connection pattern in the dielectric chip 62 such as a via hole.

Thereafter, external electrodes 66 are formed by baking on both end surfaces in the longitudinal direction of the dielectric chip 62 (FIG. 9A).
By plating the exposed conductor portions (65, 66), a laminated inductor 68 as shown in FIG.
Is manufactured.

When the method of making the stacking direction different from the thickness direction as described above is used, for example, one rod-shaped internal conductor 71 is provided inside a dielectric chip 70 as shown in FIG.
And an inductance element of which internal conductors 71 are connected to external electrodes 72 formed at both ends of the dielectric chip 62 can be manufactured.

That is, as shown in FIG. 11, a process of printing and forming a dielectric layer 75 having a hole 76 at the center and filling a conductive paste 77 in the hole 76 is repeated a predetermined number of times. A rod-shaped internal conductor 71 of a predetermined length in which the conductor paste 77 is continuous is formed. And
Since both ends of the internal conductor 71 are exposed at both ends of the chip 70, external electrodes 72 are formed around the both ends of the chip 70, and the external electrodes 72 and the internal conductor 71 are electrically connected to each other. A multilayer inductor as shown in FIG.

[0047]

As described above, in the multilayer inductor according to the present invention, the spiral coil disposed inside the dielectric chip is parallel to the axis connecting the external electrodes formed on both end faces of the dielectric chip. As a result, the coil can be formed longer than the spiral coil in the conventional multilayer inductor. Therefore, the number of turns of the spiral coil can be increased, and the L value of the multilayer inductor can be increased.

The cross-sectional shape of most of the helical coil (the portion formed by the columnar conductor patterns in the first to third embodiments) can be easily made circular or a shape close thereto, and In addition, the DC resistance can be reduced, and a high-performance multilayer inductor having a large Q value can be realized even in a high frequency region of several hundred MHz or more.

[Brief description of the drawings]

FIG. 1 shows a first example of a method for manufacturing a multilayer inductor according to the present invention.
It is a figure explaining an embodiment.

FIG. 2 shows a first example of a method for manufacturing a multilayer inductor according to the present invention.
It is a figure explaining an embodiment.

FIG. 3 is a perspective view showing an embodiment of the laminated inductor according to the present invention.

FIG. 4 shows a second example of the method for manufacturing a multilayer inductor according to the present invention.
It is a figure explaining an embodiment.

FIG. 5 shows a third example of the method for manufacturing a multilayer inductor according to the present invention.
It is a figure explaining an embodiment.

FIG. 6 shows a fourth step of the method for manufacturing a laminated inductor according to the present invention.
It is a figure explaining an embodiment.

FIG. 7 shows a fourth step of the method for manufacturing a laminated inductor according to the present invention.
It is a figure explaining an embodiment.

FIG. 8 shows a fourth embodiment of the manufacturing method of the multilayer inductor according to the present invention.
It is a figure explaining an embodiment.

FIG. 9 shows a fourth step of the method for manufacturing a multilayer inductor according to the present invention.
It is a figure explaining an embodiment.

FIG. 10 is a diagram illustrating a modified example to which the fourth embodiment is applied.

FIG. 11 is a diagram showing a modified example to which the fourth embodiment is applied.

FIG. 12 is a diagram illustrating a method for manufacturing a conventional laminated inductor.

FIG. 13 is a diagram showing a shape and an internal structure of a multilayer inductor completed by a conventional multilayer inductor manufacturing method.

FIG. 14 is a diagram illustrating a cross-sectional shape of a spiral coil in a conventional laminated inductor.

[Explanation of symbols]

16a-16d, 31a-31g, 41a, 41b Lower strip-shaped conductor patterns 18a-18h, 33a-33n, 43a-43d Holes 19a-19h, 19 "a-19" h Columnar conductor patterns 34a-34n, 34'a- 34'n Columnar conductor pattern 44a-44d, 44'a-44'd Columnar conductor pattern 22a-22e, 36a-36h, 46a-46e Upper strip conductor pattern 17, 20, 32, 35, 42, 45, 51 Dielectric Layer 53, 53 ', 55, 55', 55 "Dielectric layer 25, 62 Dielectric chip 26, 66 External electrode 27, 61 Spiral coil 52, 52 ', 54, 54', 54" 56 Conductor pattern 65 Electrode Connection pattern

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01F 41/04 H01F 15/10 C (72) Inventor Yoshinari Noyori 5-36-11 Shimbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd. In company

Claims (4)

[Claims] A helical coil having a conductor pattern connected is embedded in a chip made of an electrical insulator, and external electrodes are formed on both side surfaces in a longitudinal direction of the chip, respectively. A multilayer inductor electrically connected to the spiral coil via an electrode connection pattern, wherein a center axis of the spiral coil is parallel to a direction connecting both the external electrodes. 2. A step of printing and forming an electrical insulating layer having holes formed at positions opposing both ends of each of the lower conductive strip patterns on the electrical insulating layer on which the plurality of lower conductive strip patterns are formed; The step of printing and forming a columnar conductor pattern at positions opposed to both ends of each of the lower band-shaped conductor patterns is repeatedly performed in a predetermined order, and the columnar conductor pattern is inserted into the hole by repeating the two steps a predetermined number of times. Forming a plurality of electrical insulating layers, and forming an upper band-shaped conductive pattern on the upper surface of the uppermost electrical insulating layer of the plurality of electrical insulating layers so as to connect the predetermined columnar conductive patterns to each other. To form a helical coil by connecting the above-mentioned upper and lower strip-shaped conductor patterns and columnar conductor patterns, An insulating member is laminated on the surface of the formed electric insulating layer to form a chip in which the spiral coil is embedded, and a center axis direction of the spiral coil coincides with a longitudinal direction of the chip. And forming external electrodes at both ends in the longitudinal direction of the chip, the external electrodes being electrically connected to the upper band-shaped conductor pattern. 3. The method for manufacturing a laminated inductor according to claim 2, wherein the cross-sectional shape of the columnar conductor pattern formed inside the hole is circular. 4. An intermediate product having a helical coil connected to the conductor pattern embedded therein is formed by alternately printing and forming a conductor pattern and an electrical insulating layer alternately, and forming the intermediate product. When cutting a predetermined position to form a chip having the spiral coil therein, the longitudinal direction of the chip is set to the direction of the central axis of the spiral coil, and both ends in the longitudinal direction of the dielectric chip An external electrode is formed on a surface, and an electrode connection pattern for connecting both ends of the spiral coil and the external conductor is formed at a predetermined timing after the spiral coil is formed. Manufacturing method of inductor.