JP2001313212A - Laminated coil and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated coil which is small in size and excellent in electrical properties and a method of manufacturing the same. SOLUTION: Insulating sheets 13 on which a coil conductor pattern 12 forming a spiral coil L2 is printed respectively and protective insulating sheets 14 are laminated into a laminate. No gap is produced between the peripheral edges of the coil conductor pattern 12 and the insulating sheet 13. The peripheral edge of the coil conductor pattern 12 exposed on the side of the laminate is covered with an insulating film formed on the side of the laminate. The coil L2 is so structured as to enable its axis to form right angles with the mounting surface of the laminated coil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated coil, and more particularly to a laminated coil called a surface mount type which is directly mounted on a pattern surface of a circuit board and a method of manufacturing the same.

[0002]

2. Description of the Related Art As a conventional laminated coil of this type, for example, a coil shown in FIG. 19 is known. The laminated coil 1 includes an insulating sheet 3 provided with coil conductor patterns 2a to 2d on the surfaces thereof, and a protective insulating sheet 4 disposed on the upper and lower sides of the insulating sheet 3, for example. I have. The coil conductor patterns 2a to 2d are electrically connected in series via via holes 7a to 7c provided in the insulating sheet 3, respectively, to form a coil L1.

[0003] After the respective insulating sheets 3 and 4 are stacked, they are integrally fired to form a laminate 6 as shown in FIG. An input external electrode 8 and an output external electrode 9 are provided at the left and right ends of the laminate 6 respectively. One lead portion (specifically, end portion of coil conductor 2a) 5a of coil L1
Is electrically connected to the input external electrode 8, and the other lead portion (specifically, the end of the coil conductor 2 d) 5 b is electrically connected to the output external electrode 9.

[0004]

The electrical characteristics of a laminated coil generally have a close relationship with the inner diameter of a coil formed in a laminated body. For example, in a so-called air-core coil type laminated coil in which the insulating sheet is made of a nonmagnetic material, the Q value can be increased by increasing the inner diameter of the coil. Further, in a laminated coil of a so-called magnetic core coil type in which the insulating sheet is made of a magnetic material, the DC superposition characteristics can be improved by increasing the inner diameter of the coil.

However, the conventional laminated coil 1 is
The coil conductor patterns 2a to 2d are so exposed that the outer peripheral edges of the coil conductor patterns 2a to 2d are not exposed on the side surfaces of the laminate 6.
It was necessary to secure a gap g of a predetermined size between the outer peripheral edge of the insulating sheet 3 and the outer peripheral edge of the insulating sheet 3. Moreover, the dimensions of the gap g are determined by the coil conductor patterns 2a to 2d.
The dimension is set in consideration of the processing deviation of printing or the like. Therefore,
In the conventional laminated coil 1, the inner diameter of the coil is reduced by the amount by which the gap g must be secured, and a large Q
It was difficult to obtain a good value and good DC superimposition characteristics.

Accordingly, an object of the present invention is to provide a small-sized and
An object of the present invention is to provide a multilayer coil capable of obtaining good electrical characteristics and a method for manufacturing the same.

[0007]

In order to achieve the above object, a laminated coil according to the present invention comprises: (a) a laminated body formed by stacking a plurality of insulating layers and a plurality of coil conductor patterns; b) a coil having an axis parallel to the stacking direction of the stacked body, the coil being formed by electrically connecting the coil conductor patterns via via holes provided in the insulating layer; and (c) an axis of the coil. An input external electrode and an output external electrode which are respectively provided at both ends of the laminate in a state parallel to the direction, and both ends of the coil are respectively electrically connected; The gap between the outer peripheral edge of at least one coil conductor pattern and the outer peripheral edge of the insulating layer among the plurality of coil conductor patterns is zero, and the coil conductor exposed on the outer peripheral surface of the laminated body The outer peripheral edge portion of the turn is insulated,
In addition, the axis of the coil is perpendicular to the stacked coil mounting surface. As a material of the insulating layer, a magnetic material or a non-magnetic material is used.

[0008] With the above configuration, the coil conductor pattern is provided over the entire outer peripheral edge of the insulating layer, and the inner diameter of the coil and the width of the coil conductor pattern are increased. Further, by insulating the outer peripheral surface of the laminated body including the outer peripheral edge of the coil conductor pattern having the zero gap, the outer peripheral edge of the coil conductor pattern is prevented from being short-circuited to the outside.

Furthermore, by electrically connecting the input / output external electrodes and both ends of the coil near the corners of the laminate, the corners of the laminate are chamfered.
The leading end of the coil is easily exposed on the surface of the laminate. Therefore, the process of exposing the lead-out terminal of the coil to the surface of the laminate is simplified. Alternatively, the electrical connection between the input / output external electrodes and both ends of the coil is performed on the upper and lower surfaces facing each other of the laminate, so that the process of exposing the lead terminals of the coil to the surface of the laminate becomes unnecessary. .

Further, the method for manufacturing a laminated coil according to the present invention comprises: (e) a step of preparing a mother sheet in which coil conductor patterns are arranged so that adjacent coils share a coil conductor pattern; And (g) cutting the laminated block at the position of the coil conductor pattern and cutting out a laminate of a predetermined size from the laminated block. (H) a step of insulating the outer periphery of the coil conductor pattern exposed on the outer peripheral surface of the laminate, and (i) a step of forming an input external electrode and an output external electrode at both ends of the laminate. And characterized in that: With the above method, a laminated coil having a zero side gap between the outer peripheral edge of the coil conductor pattern and the outer peripheral edge of the insulating layer is efficiently produced.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a laminated coil according to the present invention and a method for manufacturing the same will be described below in detail with reference to the accompanying drawings.

[First Embodiment, FIGS. 1 to 6] As shown in FIG. 1, a laminated coil 11 has a coil conductor pattern 12
Are provided on the surface, an insulating sheet 13 provided with the lead-out conductor pattern 12a on the surface, a protective insulating sheet 14, and the like. Conductor pattern 1
2 and 12a are formed on the insulating sheet 13 so that the gap between the outer peripheral edge of the insulating sheet 13 and the outer peripheral edge of the conductor patterns 12 and 12a is zero. That is, the outer peripheral edges of the conductor patterns 12 and 12a are exposed at the outer peripheral edges of the insulating sheet 13.

The insulating sheets 13 and 14 are formed by forming a slurry-like raw material prepared by kneading a magnetic material (for example, ferrite) or a non-magnetic material (for example, dielectric ceramic) and a binder or the like into a sheet. is there. In the first embodiment, a magnetic material of ferrite is used as the material of the insulating sheets 13 and 14, and a so-called magnetic core coil type is used. The conductor patterns 12, 12a are made of Ag, Pd, Cu,
It is made of Au, Ag-Pd or the like, and is formed by a method such as screen printing.

The beginning and end of the coil conductor pattern 12 are electrically connected in series via a via hole 17 provided in the insulating sheet 13. This conductor pattern 12
By repeating the lamination, the number of turns of the coil required for the laminated coil 11 is obtained.

Next, a predetermined number of insulating sheets 13 provided with via holes 17 are laminated to form an intermediate conductor path 17a. The intermediate conductor track 17a is electrically connected to the conductor pattern 12. Next, the lead conductor pattern 12a
Are laminated and electrically connected to the intermediate conductor path 17 a via the via hole 17. Further, a protective insulating sheet 14 is laminated on the upper and lower sides. The lead-out conductor pattern 12a is a laminate 1 to be described later.
6, the drawer terminal 15a
Are disposed near the upper surface and the lower surface of the laminated body 16 so that they are easily exposed to the side surfaces of the laminated body 16.

As shown in FIG. 2, the laminated sheets 13 and 14 are integrally press-pressed, pressed and fired to obtain a laminate 16. Thereby, each coil conductor pattern 12 constitutes a spiral coil L2 having an axis parallel to the stacking direction of the insulating sheets 13 and 14.

Next, the four side surfaces of the laminated body 16 are
Cover with 0. As a result, the outer peripheral edge of the coil conductor pattern 12 exposed on the side surface of the multilayer body 16 is insulated. As a material of the insulating film 20, a resin or glass coating material, a non-magnetic ceramic paste, or the like is used. When a resin or glass coating material is used for the insulation treatment, a polymer resin such as epoxy or polyimide or a glass material is applied to the side surface and cured at an appropriate temperature to obtain the insulating film 20. At this time, the insulating film 20 may be formed by a method other than coating, such as dipping, printing, or spraying. Also,
When a glass paste or a non-magnetic ceramic paste is used for the insulating process, a film is formed in the same manner and fired to obtain the insulating film 20. In the first embodiment, the insulating film 20 is formed so as to cover only the four side surfaces of the multilayer body 16, but may be formed on the entire surface of the multilayer body 16.

Next, as shown in FIGS. 3 and 4, the corner of the laminate 16 on the side of the lead-out terminal 15a of the lead-out conductor pattern 12a is chamfered to expose the lead-out terminal 15a. The corners are chamfered by a method such as machining or barrel polishing.

Next, the laminated body 1 from which the drawer terminal 15a is exposed
No. 6, two side portions, Ni, Ag, Pd, Ag-Pd
The input external electrode 18 and the output external electrode 19 are provided by a method such as coating, baking, and plating. The external electrodes 18 and 19 are electrically connected to the lead terminal 15a of the lead conductor pattern 12a. When the side surface of the laminate 16 is insulated with resin, a material that can be cured at a low temperature is used as the material of the input external electrode 18 and the output external electrode 19. For example, a thermosetting conductive adhesive is used. The external electrodes 18 and 19 are arranged parallel to the stacking direction of the sheets 13 and 14. Laminate 1
The lower surface 16a of 6 is used as a mounting surface when the coil 11 is soldered to a printed circuit board or the like. Therefore, the stacking direction of the sheets 13 and 14 is perpendicular to the mounting surface 16a, and the axial direction of the coil L2 is also perpendicular.

Thus, the so-called magnetic core type laminated coil 11 in which the insulating sheets 13 and 14 are made of a magnetic material is obtained. In this laminated coil 11, since the gap between the outer peripheral edge of the coil conductor pattern 12 and the outer peripheral edge of the insulating sheet 13 is zero, the coil conductor pattern 12 is removed from the outer peripheral edge of the insulating sheet 13. Can be formed completely. This makes it possible to increase the inner diameter of the coil L2 and improve the DC superimposition characteristics.
Alternatively, the DC resistance value of the coil conductor pattern 12 can be reduced by setting the pattern width of the coil conductor pattern 12 wide while keeping the inner diameter of the coil L2 the same as that of the conventional laminated coil.

Since each coil conductor pattern 12 has a portion exposed on the side surface of the laminate 16 covered with the insulating film 20, there is no fear that the outer peripheral portion of the coil conductor pattern 12 is short-circuited to the outside world. . Since the insulating film 20 is made of a non-magnetic material, it is difficult to form a magnetic path. Therefore, magnetic flux hardly passes through the insulating film 20 and the insulating film 2
Since there is almost no wraparound of the magnetic flux through 0, the magnetic resistance increases and magnetic saturation hardly occurs, and the DC superposition characteristics are further improved.

When a low-permeability magnetic material, that is, a resin containing magnetic powder or a low-permeability ferrite paste, is used instead of the non-magnetic material as the material of the insulating film 20, Will form a magnetic path. Therefore, the magnetic flux easily passes through the insulating film 20, and the wraparound of the magnetic flux increases, so that the inductance can be increased or the DC resistance can be reduced. Even in this case, since the insulating film 20 is thin, the effect of the DC superimposition characteristic is not significantly impaired. By using a magnetic material for the insulating film 20 in this way, it is also possible to adjust the electrical characteristics of the multilayer coil 11.

Next, an example of a manufacturing method for mass-producing the multilayer coil 11 will be described with reference to FIGS.

The grid-like conductor patterns 31 and 32 shown in FIG. 5A and FIG.
This is for forming the coil conductor pattern 12 in the portion indicated by. The lattice-shaped conductor patterns 31 and 32
This is a rectangular lattice pattern having a pattern width twice as large as the coil conductor pattern 12 and a longitudinal dimension twice as large as the insulating sheet 13. FIG. 5 (b)
The grid-like conductor pattern 32 is rotated 90 degrees with respect to the grid-like conductor pattern 31 of FIG. These grid-like conductor patterns 31 and 32 are formed on the surfaces of the mother sheets 41 and 42 having a large area by screen printing or the like. The mother sheets 41 and 42 are the portions of the insulating sheet 1 indicated by the symbol A in FIG.
3 is formed. Further, via holes 17 are formed at predetermined positions in the mother sheets 41 and 42.

The mother sheet 43 shown in FIG. 6A is for forming the insulating sheet 13 for the intermediate conductor path 17a at the portion indicated by the symbol B in FIG. . Via hole 17 for intermediate conductor track 17a
Are regularly and vertically provided on the mother sheet 43 at a predetermined pitch dimension. The via hole 17 is formed by filling a hole formed in a wide area mother sheet 43 with a conductive paste.

The mother sheet 4 shown in FIG.
4 is for forming the insulating sheet 13 of the lead-out conductor pattern 12a at the portion indicated by the symbol C in FIG. The stripe pattern 33 has a pattern width twice as large as the pattern width of the lead conductor pattern 12a. The stripe pattern 33 is formed on the surface of the mother sheet 44 having a large area by a method such as screen printing, similarly to the lattice-shaped conductor patterns 31 and 32.
As shown in FIG. 6B, the mother sheet 44 includes a stripe pattern 33 having via holes 17 formed therein.
Two types, one in which only the stripe pattern 33 is formed, are created.

The mother sheets 41 to 4 thus prepared
4 are laminated by a predetermined number. At this time, a region A1 surrounded by a dashed line of the sheet 41 (see FIG. 5A) and a region B1 surrounded by a dashed line of the sheet 42 (see FIG. 5A).
(See (b)).
Is set. Next, the set sheets 41 and 4 are set.
The sheet 41 is set so that an area B1 of the sheet 42 and an area A2 (see FIG. 5A) surrounded by a dashed line of the sheet 41 vertically overlap under the sheet 2. Further, under the sheet 41, the sheet 42 is set so that an area A2 of the sheet 41 and an area B2 (see FIG. 5B) surrounded by a dashed line of the sheet 42 vertically overlap. In this way, the sheets 41 and 42 are sequentially and alternately stacked.

Sheets 43 are further laminated above and below the laminated sheets 41 and 42. At this time, the sheet 43 stacked on the upper side is set so that an area A1 of the sheet 41 and an area C1 (see FIG. 6A) surrounded by a dashed line of the sheet 43 vertically overlap. The sheet 43 stacked on the lower side is set so that the area A2 of the sheet 41 and the area C2 surrounded by the dashed line of the sheet 43 are vertically overlapped.

Further, sheets 44 are stacked on and under the stacked sheets 41 to 43. At this time, the sheet 44 stacked on the upper side is provided with the via hole 17, and the area C1 of the sheet 43 and the area D1 (see FIG. 6B) surrounded by a dashed line of the sheet 44 are vertically shifted. Set to overlap. The sheet 44 laminated on the lower side does not have the via hole 17. After this, sheet 41
Protective mother sheets are laminated above and below to obtain a laminated block body.

The laminated block body is integrally pressed, pressed, baked, and then cut for each product size.
The laminate 16 shown in FIG. 2 is obtained. At this time, the conductor patterns 31 to 33 and the mother sheets 41 to 44 shown in FIGS. 5 and 6 are cut at the positions indicated by the dashed lines. The firing may be performed after cutting the laminated mother sheet into a predetermined product size.
Thereafter, as described above, after the insulating film 20 is formed on the side surface of the stacked body 16, the external electrodes 18 and 19 are formed.

According to the above-described manufacturing method, a laminated coil having a zero gap between the outer peripheral edge of the coil conductor pattern 12 and the outer peripheral edge of the insulating sheet 13 can be efficiently obtained. In addition, if the pattern width of the coil conductor pattern 12 is increased in order to cut the conductor patterns 31 to 33, the processing accuracy at the time of cutting can be relaxed, and the production yield of the laminated coil 11 can be reduced.

[Second Embodiment, FIGS. 7 to 11] As shown in FIG. 7, the laminated coil 21 has a coil conductor pattern 1
2 is provided on the surface, an insulating sheet 13 provided with the intermediate conductor pattern 12b on the surface, and the like. The conductor patterns 12 and 12b are insulated so that the gap between the outer periphery of the insulation sheet 13 and the outer periphery of the conductor patterns 12 and 12b is zero.
Is formed on. That is, the conductor patterns 12, 12
The outer peripheral edge of b is exposed at the outer peripheral edge of the insulating sheet 13.

As in the first embodiment, the insulating sheet 13 is made of a slurry-like raw material prepared by kneading a magnetic material (for example, ferrite) or a non-magnetic material (for example, dielectric ceramic) and a binder. It is a sheet. In the second embodiment, a so-called magnetic core coil type is used as the material of the insulating sheet 13 using a ferrite magnetic material.

The coil conductor pattern 12 is electrically connected in series at the beginning and end thereof via holes 17 provided in the insulating sheet 13. By repeating the conductor pattern 12, the number of turns of the coil required for the multilayer coil 21 is obtained. Next, the insulating sheet 13 provided with the intermediate conductive pattern 12b is laminated, and is electrically connected to the end of the conductive pattern 12 via the via hole 17.

Further, a predetermined number of insulating sheets 13 provided with via holes 17 are laminated to form a lead conductor path 17b. The lead conductor path 17b is used for the intermediate conductor pattern 12.
b. The lead conductor path 17b is provided near the upper right side and near the lower left side of the laminated body 26 so as to be easily electrically connected to the external electrodes 18 and 19 described later. As shown in FIG. 8, the laminated insulating sheets 13 are integrally pressed and pressed, baked, and fired to form a laminate 26.
It is said. Thus, a helical coil L3 having an axis parallel to the stacking direction of the insulating sheets 13 is configured.

Next, the four side surfaces of the laminated body 26 are
Cover with 0. As a result, the outer peripheral edge of the coil conductor pattern 12 exposed on the side surface of the multilayer body 26 is insulated. Next, as shown in FIGS. 9 and 10, the input external electrode 18 and the output external electrode 19 are provided on the right and left side surfaces of the stacked body 26. These external electrodes 18 and 19 are each electrically connected to the lead conductor path 17b. External electrodes 18, 19
Are arranged parallel to the stacking direction of the insulating sheets 13. The lower surface 26a of the multilayer body 26 is used as a mounting surface when the multilayer coil 21 is soldered to a printed circuit board or the like. Therefore, the stacking direction of the insulating sheets 13 is perpendicular to the mounting surface 26a, and the axial direction of the coil L3 is also perpendicular.

Thus, the so-called magnetic core type laminated coil 2 in which the insulating sheet 13 is made of a magnetic material.
1 is obtained. The multilayer coil 21 has the same operation and effect as the multilayer coil 11 of the first embodiment. In addition, in the first embodiment, the terminal exposing process of the coil is required after the insulation treatment. However, in the second embodiment, the terminal exposing process can be omitted, and the laminated coil 21 can be provided at lower cost.

Next, an example of a manufacturing method for mass-producing the multilayer coil 21 will be described with reference to FIGS.

As in the first embodiment, the grid-like conductor patterns 31, 32 shown in FIGS. 5A and 5B are used.
Is for forming the coil conductor pattern 12 at the portion indicated by the symbol A in FIG. The mother sheets 41 and 42 are for forming the insulating sheet 13 at a portion indicated by a symbol A in FIG.

The mother sheet 45 shown in FIG. 11A is for forming the intermediate insulating sheet 13 at the portion indicated by the symbol B in FIG. The I-shaped pattern 34 includes the intermediate conductor pattern 12b.
Has a pattern width twice as large as the pattern width. The I-shaped pattern 34 is formed on the surface of a large-area mother sheet 45 by a method such as screen printing, similarly to the lattice-shaped conductor patterns 31 and 32. The mother sheet 45
As shown in FIG. 11A, two via holes 17 are arranged at the center of the I-shaped pattern 34 and two via holes 17 are arranged at the four corners of the I-shaped pattern 34. A type is created.

The mother sheet 46 shown in FIG. 11 (b) is for forming the insulating sheet 13 of the lead-out conductor path 17b in the portion indicated by the symbol C in FIG. The via holes 17 forming the lead-out conductor path 17b are regularly and vertically provided in the mother sheet 46 at a predetermined pitch dimension.

The mother sheets 41, 4 thus prepared
2, 45 and 46 are each laminated by a predetermined number. The sheets 41 and 42 are sequentially and alternately stacked in the same manner as in the first embodiment. Sheets 45 are further stacked above and below the stacked sheets 41 and 42. At this time, the sheet 45 stacked on the upper side has four via holes 17 provided in the center of the I-shaped pattern 34, and the area A1 of the sheet 41 and the area E1 surrounded by the dashed line of the sheet 45.
(See FIG. 11A). The sheet 45 laminated on the lower side is provided with via holes 17 at four corners of the I-shaped pattern 34, respectively, and the area A2 of the sheet 41 and the via holes 17 are provided at the four corners of the I-shaped pattern 34, respectively. The sheet 45 on which the sheet 17 is provided is set so as to overlap with a region E2 surrounded by a dashed line.

Further, the laminated sheets 41, 42, 4
A predetermined number of sheets 46 are stacked above and below the sheet 5. At this time, the sheet 46 stacked on the upper side includes an area E1 of the sheet 45 and an area F1 (see FIG.
1 (b)).
The sheet 46 laminated on the lower side is a sheet 4 in which via holes 17 are provided at four corners of the I-shaped pattern 34, respectively.
5 and a region F surrounded by a dashed line of the sheet 46.
2 (see FIG. 11B) are set so as to overlap vertically.

In this manner, similarly to the first embodiment, it is possible to efficiently obtain a laminated coil in which the gap between the outer peripheral edge of the coil conductor pattern 12 and the outer peripheral edge of the insulating sheet 13 is zero. it can.

[Third Embodiment, FIGS. 12 to 18] FIG.
As shown in FIG. 5, the laminated coil 30 includes an insulating sheet 13 provided with the coil conductor pattern 12 on the surface, an insulating sheet 13 provided with the lead-out conductor pattern 12c on the surface, an insulating sheet 14 for protection, and the like. It is configured. The leading conductor pattern 12c is formed on the insulating sheet 13 so that the gap between the outer peripheral edge of the insulating sheet 13 and the outer peripheral edge of the leading conductor pattern 12c is zero.
The coil conductor pattern 12 is formed such that the gap between the front side and the rear side of the insulating sheet 13 is zero.

In the case of the third embodiment, the insulating sheets 13,
As a material of 14, using a glass-based ceramic material,
It was a so-called air-core coil type.

The beginning and end of the coil conductor pattern 12 are electrically connected via a via hole 17 provided in the insulating sheet 13. By repeating the lamination of the conductor patterns 12, the number of turns required for the laminated coil 30 is obtained.

Next, the insulating sheet 13 provided with the lead-out conductor pattern 12c is laminated, and the lead-out conductor pattern 12c is connected via the via hole 17 to the conductor pattern 12c.
Is electrically connected to the outermost part. Further, a predetermined number of protective insulating sheets 14 are laminated on the upper and lower sides. As shown in FIG. 13, the laminated insulating sheets 13 and 14 are integrally pressed, pressed, and fired to form a laminate 36. Thus, a helical coil L4 having an axis parallel to the stacking direction of the sheets 13 and 14 is formed.

Next, the two side surfaces on the near side and the back side of the laminated body 36 are covered with the insulating film 20. Thereby, the laminate 3
6, the coil conductor pattern 12 exposed on the two side surfaces
Is insulated at the outer periphery.

Next, as shown in FIGS. 14 to 16, an input external electrode 18 and an output external electrode 19 are provided on the right and left side surfaces of the laminated body 36. The external electrodes 18 and 19 are connected to the lead terminals 15c of the lead conductor pattern 12c. The external electrodes 18 and 19 are arranged parallel to the stacking direction of the sheets 13 and 14. The lower surface 36a of the laminate 36 is
It is used as a mounting surface when soldering the coil 30 to a printed circuit board or the like. Therefore, the stacking direction of the sheets 13 and 14 is perpendicular to the mounting surface 36a, and the coil L
4 is also vertical. In order to suppress the generation of stray capacitance generated between the folded portions of the external electrodes 18 and 19 and the lead conductor pattern 12c, the folded portions of the external electrodes 18 and 19 are preferably as small as possible.

Thus, a so-called air-core type laminated coil 30 in which the insulating sheets 13 and 14 are made of a non-magnetic material is obtained. In this laminated coil 30, the gap between a part of the outer peripheral edge of the coil conductor pattern 12 and the outer peripheral edge of the insulating sheet 13 is zero. The outer peripheral portion can be formed completely. This makes it possible to increase the inner diameter of the coil L4 and improve the Q characteristics. Alternatively, the DC resistance value of the coil conductor pattern 12 can be reduced by setting the pattern width of the coil conductor pattern 12 wide while keeping the inner diameter of the coil L4 the same as that of the conventional laminated coil.

In the laminated coil 30, a gap similar to the conventional one is provided on the two side surfaces of the laminated body 36 forming the external electrodes 18 and 19, and the stray capacitance generated at this portion can be suppressed. it can. As a result, it is possible to obtain the laminated coil 30 having higher Q characteristics while securing the high-frequency characteristics required for the air-core coil.

Further, since the portions of each coil conductor pattern 12 exposed on the two side surfaces of the laminated body 36 are covered with the insulating film 20, there is a concern that the outer peripheral edge of the coil conductor pattern 12 is short-circuited to the outside world. There is no.

In the first embodiment, the coil end exposing process is required after the insulation treatment. However, in the third embodiment, the terminal exposing process can be omitted, and the laminated coil 30 can be manufactured at lower cost.
Can be provided. Further, in the related art, the gap g was required in both the X and Y directions, but in the third embodiment, the gap g in only one direction is sufficient, and the processing can be facilitated as compared with the related art.

Next, an example of a manufacturing method for mass-producing the multilayer coil 30 will be described with reference to FIGS.

The conductor patterns 31a and 32a shown in FIGS. 17 (a) and 17 (b) are for forming the coil conductor pattern 12 indicated by the symbol A in FIG. Conductor patterns 31a, 32a
Is a pattern having a pattern width equivalent to the pattern width of the coil conductor pattern 12, a pattern width twice as large as the pattern width of the pattern 12, and having a longitudinal dimension twice as large as the dimension of the insulating sheet 13. These conductor patterns 31
a and 32b are wide-area mother sheets 47 and 4 respectively.
8 is formed by a technique such as screen printing. The mother sheets 47 and 48 are for forming the insulating sheet 13 at a portion indicated by a symbol A in FIG. Further, via holes 17 are formed at predetermined positions in the mother sheets 47 and 48.

The mother sheet 49 shown in FIG. 18 is for forming the insulating sheet 13 for the lead-out conductor pattern 12c at the portion indicated by the symbol B in FIG. The pattern 35 has a pattern width twice the pattern width of the coil conductor pattern 12c. The pattern 35 is formed on the surface of the mother sheet 49 having a large area by a method such as screen printing, similarly to the patterns 31a and 32a. As shown in FIG. 18, the mother sheet 49 is formed by forming via holes 17 in the stripe pattern 35 and the stripe pattern 3.
Two types, one in which only 5 is formed, are created.

Mother sheets 47 to 4 thus prepared
9 are laminated by a predetermined number. At this time, FIG.
7A and FIG. 17B, a region A1 surrounded by a dashed line of the sheet 47 (see FIG. 17A) and a region B1 surrounded by a dashed line of the sheet 48 (see FIG. 17B). ) Are set so that the sheets 47 and 48 overlap vertically. Next, under these set sheets 47 and 48,
The sheet 47 is set so that an area B1 of the sheet 48 and an area A2 (see FIG. 17A) surrounded by a dashed line of the sheet 47 overlap vertically. Further, under the sheet 47, the sheet 48 is set so that an area A2 of the sheet 47 and an area B2 (see FIG. 17B) surrounded by a dashed line of the sheet 48 overlap vertically. Thus, the sheets 47 and 48 are sequentially and alternately stacked.

Sheets 49 are further stacked above and below the stacked sheets 47 and 48. At this time, the sheet 49 laminated on the upper side is formed by forming the via holes 17 in the stripe pattern 35, and the area A1 of the sheet 47 is formed.
And a region C1 (see FIG. 18) surrounded by a dashed line of the sheet 49 is set so as to overlap vertically. The sheet 49 to be laminated on the lower side has only the stripe pattern 35 formed thereon, and includes an area A2 of the sheet 47 and an area C2 surrounded by a dashed line of the sheet 49 formed only with the stripe pattern 35. Are set so that they overlap vertically.

Further, protective mother sheets are laminated above and below the laminated sheets 47 to 49 to obtain a laminated block body.

The laminated block body is integrally press-pressed, pressed and fired, and then cut for each product size.
A laminate 36 shown in FIG. 13 is obtained.

[Other Embodiments] The present invention is not limited to the above embodiment, but can be variously modified within the scope of the gist. When manufacturing laminated coils,
After stacking the insulating sheets provided with the coil conductor patterns on the surface, a method of integrally pressing, pressing, and firing is not necessarily limited. As the insulating sheet, a pre-fired one may be used.

Further, a laminated coil may be manufactured by the method described below. That is, after forming an insulating layer with a paste-like insulating material by a method such as printing, a paste-like conductive material is applied to the surface of the insulating layer to form a coil conductor pattern. Next, a paste-like insulating material is applied over the coil conductor pattern to form an insulating layer in which the coil conductor pattern is embedded. Similarly, a coil having a laminated structure can be obtained by electrically connecting necessary portions of the coil conductor pattern while successively coating.

[0064]

As is apparent from the above description, according to the present invention, the gap between the outer peripheral edge of each coil conductor pattern and the outer peripheral edge of the insulating layer is zero. In addition, the coil conductor pattern can be provided over the entire outer peripheral edge of the insulating layer. As a result, the inner diameter of the coil and the width of the coil conductor pattern can be increased. In the case of a so-called air-core coil type laminated coil, the Q value can be increased. In the case of a laminated coil, DC superimposition characteristics can be improved.

Further, since the insulating sheet is laminated in the direction perpendicular to the mounting surface of the laminated coil, and the coil has a built-in coil whose axial direction is perpendicular to the mounting surface, the structure is a vertically wound coil. The thickness of the coil can be reduced.

In the case of a so-called magnetic core coil type laminated coil, if the insulating film is made of a non-magnetic material, almost no magnetic flux wraps around the insulating film.
The DC resistance is further improved by increasing the magnetic resistance of the coil. Moreover, in the conventional coil, when plating the external electrode, the coil is magnetized by the plating current, and the inductance is reduced. However, the coil of the open magnetic path is formed by forming the insulating film from a non-magnetic material. By doing so, this problem can be solved. On the other hand, when the insulating film is made of a ferrite material having a low magnetic permeability or a resin containing a magnetic powder, the wraparound of the magnetic flux increases, thereby increasing the inductance and reducing the DC resistance. Even in this case, since the insulating film is thin, the effect of the DC superimposition characteristic is not significantly impaired. As described above, by using the magnetic material as the material of the insulating film, it is also possible to adjust the electric characteristics of the multilayer coil.

Further, according to the present invention, it is not necessary to consider the dimensional accuracy of the gap when manufacturing the laminated coil, the coil conductor pattern can be easily formed, the yield is good, and the mass productivity is good. A coil is obtained.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing the appearance of the multilayer body of the multilayer coil shown in FIG.

FIG. 3 is a perspective view showing the appearance of the multilayer coil shown in FIG. 1;

FIG. 4 is a sectional view taken along line XX of FIG. 3;

FIGS. 5A and 5B are partial plan views of a mother sheet used when manufacturing a laminated coil. FIG.

FIGS. 6A and 6B are partial plan views of a mother sheet used when manufacturing a laminated coil.

FIG. 7 is an exploded perspective view showing the configuration of a second embodiment of the multilayer coil according to the present invention.

FIG. 8 is a perspective view showing the appearance of the multilayer body of the multilayer coil shown in FIG. 7;

FIG. 9 is a perspective view showing the appearance of the laminated coil shown in FIG. 7;

FIG. 10 is a sectional view taken along line XX of FIG. 9;

11A and 11B are partial plan views of a mother sheet used when manufacturing a laminated coil.

FIG. 12 is an exploded perspective view showing a configuration of a third embodiment of the multilayer coil according to the present invention.

FIG. 13 is a perspective view showing the appearance of the multilayer body of the multilayer coil shown in FIG. 12;

FIG. 14 is a perspective view showing the appearance of the multilayer coil shown in FIG. 12;

FIG. 15 is a sectional view taken along line XX of FIG. 14;

FIG. 16 is a sectional view taken along line YY of FIG. 14;

FIGS. 17A and 17B are partial plan views of a mother sheet used when manufacturing a laminated coil.

FIG. 18 is a partial plan view of a mother sheet used when manufacturing a laminated coil.

FIG. 19 is an exploded perspective view showing the configuration of a conventional laminated coil.

FIG. 20 is a perspective view showing the appearance of the multilayer coil shown in FIG. 19;

[Explanation of symbols]

 11, 21, 30 ... laminated coil 12 ... coil conductor pattern 13, 14 ... insulating sheet 15a, 15c ... lead terminal 16, 26, 36 ... laminate 17 ... via hole 18 ... input external electrode 19 ... output external electrode 20 ... Insulating film 41-49: Mother sheet L2, L3, L4: Coil

Claims (5)

[Claims] 1. A laminate comprising a plurality of insulating layers and a plurality of coil conductor patterns stacked on each other, and the laminate comprising electrically connecting the coil conductor patterns via via holes provided in the insulating layer. A coil having an axis parallel to the stacking direction of the body, and provided at both ends of the laminated body in a state parallel to the axial direction of the coil, and both ends of the coil are electrically connected to each other. An input external electrode and an output external electrode are connected to each other, and a gap between an outer peripheral edge of at least one coil conductor pattern and an outer peripheral edge of the insulating layer among the plurality of coil conductor patterns is zero. Wherein the outer peripheral edge of the coil conductor pattern exposed on the outer peripheral surface of the laminate is insulated, and the axis of the coil is perpendicular to the laminated coil mounting surface. Laminated coil to be. 2. The multilayer coil according to claim 1, wherein the input external electrode and the output external electrode are electrically connected to both ends of the coil near corners of the multilayer body. 3. The laminate according to claim 1, wherein the input external electrode and the output external electrode and both ends of the coil are electrically connected to each other at upper and lower surfaces of the multilayer body opposed to each other. Stacked coil. 4. The laminated coil according to claim 1, wherein the insulating layer is made of a magnetic material. 5. A step of creating a mother sheet in which coil conductor patterns are arranged so that adjacent coils share a coil conductor pattern, and a step of laminating the mother sheets to form a laminated block body. Cutting the laminated block body at the position of the coil conductor pattern and cutting out a laminated body of a predetermined size from the laminated block body; insulating an outer peripheral edge of the coil conductor pattern exposed on an outer peripheral surface of the laminated body; A method of manufacturing a laminated coil, comprising: a step of treating; and a step of forming an input external electrode and an output external electrode at both ends of the laminate.