JPH09162045A - Coil component and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component with an especially excellent characteristic, in relation to the coil component itself and its manufacturing method. SOLUTION: In a coil component having a conductor 2 with a plurality of turns in the inner surface of a hollow body-like insulator 1, the conductor 2 is configured so that the diameters of its respective turn portions are different from each other gradually from its one end to its other end and at least its each turn portion is positioned in the different plate from its other turn portions. Thereby, coil component both having the excellent electric characteristic capable of reducing both the stray capacitance between its two turn portions and the DC resistance of the conductor 2 and having the structure capable of manufacturing it easily with a small quantity of manhours is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil component used for various electronic devices and communication devices, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Coil components are widely used as coils and transformers for various electronic devices and communication devices. In recent years, small or thin coil components have been increasingly required. As a result, coil components as noise suppression components are becoming more and more important.

As a conventional coil component satisfying these demands, a laminated coil component obtained by alternately laminating ferrite magnetic layers and coil conductor layers (for example, Japanese Patent Publication No. 57-3).
9521).

In this laminated coil component, as shown in FIGS. 13 and 14, a ferrite layer 12 is formed on one half of a ferrite green sheet 16 by printing, and a portion without the ferrite layer 12 and a portion of the ferrite layer 12 are formed. An L-shaped conductor pattern 13 is formed by printing on the conductor pattern 13, and about half the ferrite layer 14 of the green sheet 16 is printed on the conductor pattern 13, and the ferrite layer 12 and the ferrite layer 12 are continuous so as to be continuous with the conductor pattern 13. A U-shaped conductor pattern 15 is printed on a part of 14 and this process is repeated several times to collectively fire one in which a ferrite green sheet 16 is laminated on the uppermost layer, and end face electrodes 17 are formed on both ends of this laminated body. Formed and configured.

[0005]

With the above-mentioned structure, it is necessary to increase the number of turns of the conductor pattern in order to obtain a large inductance, and an extremely large number of ferrite layers 12 and 14 and conductor patterns 13 and 15 are laminated. Since it is necessary to print, the number of production steps is increased, and there is a problem in terms of productivity.
Since they are formed so as to face each other via the electrodes 2 and 14, there is a problem that the stray capacitance between the conductor patterns becomes large, and the self-resonance frequency of the coil component becomes small and the breakdown voltage is small.

Further, in this laminated coil component, since the conductor pattern is formed on a part of the ferrite layer, if the thickness of the conductor pattern is increased in order to reduce the resistance of the coil conductor, the entire thickness of the conductor pattern 13 is reduced. , 15 and the part where there is no marked difference, and cracks were generated even if fired, and a coil component of stable quality could not be obtained.

An object of the present invention is to provide a coil component which eliminates the above-mentioned drawbacks of the prior art, is excellent in productivity, has a small stray capacitance and is excellent in electric characteristics, and a method for manufacturing the same.

[0008]

In order to solve the above problems, the coil component of the present invention comprises a plurality of turns on the inner surface of a hollow insulator having a conical or pyramidal hollow at the center. A conductor is provided, and the diameter of each turn portion of the conductor gradually changes from one end to the other end, and at least each turn portion is located in a different plane.

According to the present invention, a coil component having excellent productivity and excellent electrical characteristics can be obtained.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention comprises a conductor consisting of a plurality of turns on the inner surface of a hollow insulator having a conical or pyramidal hollow portion provided at the center, The diameter of each turn part of this conductor gradually changes from one end to the other end, and at least each turn part is located in a different plane, which is easy to produce and the stray capacitance between the turn parts of the conductor can be improved. It can be small and have excellent electrical characteristics.

According to the second aspect of the present invention, each turn portion of the conductor is formed in the same plane from one end to the other end, and is connected to the adjacent turn portion at the terminal end or the starting end of each turn. Therefore, it is possible to easily form the extraction lead.

According to the third aspect of the invention, the conductor has a three-dimensional spiral winding shape from one end to the other end, and the conductor can be formed extremely easily.

The invention described in claims 4 and 5 is
The shape of each turn portion of the conductor is circular or rectangular, which facilitates formation of the conductor pattern and can obtain a large inductance in the same volume.

According to a sixth aspect of the present invention, a conductor is formed so that a gap between the conductors cannot be seen between the turn portions when viewed from the side of the large-diameter turn portion. Since a conductor having a large width can be formed in a limited space, excellent characteristics can be obtained.

According to a seventh aspect of the present invention, the conductor has a rectangular cross section, a circular shape, or a semicircular cross section, whereby the conductor cross section can be increased and the DC conductor resistance can be reduced.
It can also be used for high power.

According to the invention of claim 8, a non-magnetic material is used as an insulator, and the self-resonant frequency is increased and the frequency band used is widened.

According to the ninth aspect of the present invention, a magnetic body is used as an insulator, and a large inductance value can be obtained.

According to a tenth aspect of the present invention, the insulator is composed of two or more kinds having different magnetic properties, and the coil component having the same conductor structure and various inductance values or various DC superposition characteristics. Can be realized.

The invention according to claim 11 uses a non-magnetic material and a magnetic material having different magnetic properties, and can improve the DC superimposition characteristics, various inductance values, or the frequency band used. it can.

According to a twelfth aspect of the present invention, the surface of the insulator has a terminal electrode layer electrically connected to one end or the other end of the conductor, and can be a surface mountable coil component. .

According to a thirteenth aspect of the present invention, there is provided a step of forming a hollow insulator having a conical or pyramidal hollow portion in the center, and a plurality of turns on the inner surface of the hollow insulator. That is, the diameter of each turn portion gradually changes from one end to the other end, and the coil component is manufactured from the step of forming the conductor so that at least each turn portion is located in a different plane. That is, a conductor consisting of a plurality of turns is provided on the inner surface of a hollow insulator having a conical or pyramidal hollow at the center, and the diameter of each turn of this conductor gradually changes from one end to the other. At the same time, since at least the respective turn parts are formed so as to be located in different planes, it is easy to produce, and the obtained coil component has a small stray capacitance between the turn parts of the conductor and excellent electrical characteristics. it can.

According to the fourteenth and fifteenth aspects of the present invention, the step of forming a hollow-body-shaped insulator having a conical or pyramidal hollow portion in the center comprises forming the cone-shaped or pyramidal-shaped insulator on the insulator. Insulator slurry is poured on a support having a convex portion for forming a hollow portion, and an inner surface of the hollow body provided with a conical or pyramidal hollow portion forms an insulator having a sloped surface or a stepped surface. In the process, a uniform insulator can be obtained, and a hollow insulator having a conical or pyramidal hollow portion in the center can be formed with excellent productivity.

According to the sixteenth aspect of the present invention, the step of forming a hollow insulator having a conical or pyramidal hollow portion in the center comprises the step of forming a flat sheet insulator. , A step of forming a conical or pyramidal hollow portion in the center of the insulator, and by dividing into two steps, a sharable solid-state insulator can be produced with excellent productivity. By forming a hollow body-shaped insulator with a conical or pyramidal hollow part in the center into a shape suitable for the required electrical characteristics, coil parts with various electrical characteristics can be manufactured with excellent productivity. Can be formed.

In the invention according to claims 17 and 18, the step of forming a conical or pyramidal hollow portion in the center of the insulator forms a conical or pyramidal hollow portion in the insulator. Is a step of molding an insulator with a mold having a convex portion composed of slopes or stepwise slopes for forming coil parts having various electrical characteristics with excellent productivity by changing the mold shape. Is possible.

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is a perspective view schematically seeing through a typical example of the coil component of the present invention. That is, a conductor 2 having a plurality of turns is provided on the inner surface of a hollow insulator 1 having a conical (or pyramidal) hollow portion provided in the center, and the conductor 2 extends from one end to the other end of each turn portion. Is formed by a circle having a gradually increasing diameter, and the positions of the respective turn parts are located in different planes. That is, one end of the conductor 2 is formed with a small diameter circle, and the diameter is gradually increased toward the other end,
Each turn part rises or falls at the terminal end or the starting end and is connected to an adjacent turn part. Therefore, each turn portion is located on the same plane, and adjacent turn portions are located on different plane portions depending on rising and falling portions, and are set to have different diameters. In the example of FIG. 1, the number of turns is about one in the same plane, but the number of turns may be the same as in a generally known planar spiral coil.

Lead-out portions 3 and 4 are provided at both ends of the conductor 2, and the lead-out portions 3 and 4 are respectively connected to end face electrodes 5 and 6 provided on both sides of the insulator 1.

Each turn in this case is as shown in FIG.
It means a conductor existing in the same plane. That is, in the example shown in FIG. 1, it can be said that each turn is formed on four planes.

The coil component shown in FIG. 2 has a three-dimensional spiral shape in which the diameter of the conductor 2 gradually increases from one end to the other end and the positions are all located in different planes. Has the same configuration as in FIG.

FIG. 3 is a cross-sectional view of the coil component shown in FIGS. 1 and 2, in which the conductor 2 is the inner surface of the hollow insulator 1, that is, the conical or pyramidal hollow portion 7. It is configured to be formed on the inclined surface of. Here, the insulator 1 is made of one kind of material, and the insulator 1 may be a non-magnetic substance or a magnetic substance.

As the non-magnetic substance, any electrically insulating material such as an organic insulating material such as glass epoxy or polyimide, an inorganic insulating material such as glass, glass ceramics or ceramics, and the like can be used. May be.

As the magnetic material, NiZn system or NiZnC is used.
Any ferrite material having a generally high magnetic permeability, such as a u-based material, may be used.

When the insulator 1 is made of a magnetic material, the inductance value can be increased, and when the insulator 1 is made of a non-magnetic material, a large inductance value cannot be obtained. However, the self-resonant frequency becomes high and the usable frequency band is increased. Becomes wider.

Any material may be used as the material for the conductor 2 or the lead-out portions 3 and 4 as long as it is an electrically good conductor. However, since a material having a low resistivity and a low resistance is required for the coil component, copper and silver are used. Conductive materials such as palladium alloy or silver are effective.

The end electrodes 5 and 6 may be made of a conductive material, but it is generally preferable that the end electrodes 5 and 6 are composed of a plurality of layers instead of a single layer, and in the case of surface mounting, they are mounted on a printed wiring board. It is necessary to consider the mounting strength at the time of soldering, the wettability of solder at the time of mounting, the solder nick, etc. Specifically, use the same conductive material as the lead-out parts 3 and 4 for the bottom layer, and to the solder for the intermediate layer. And nickel having high resistance to the solder, and solder or tin having good wettability to solder are used for the outermost layer.

However, this is an example, and it is not always necessary to adopt this configuration, and a conductive resin material may be contained in addition to a material having excellent conductivity such as metal.

Further, a predetermined wiring pattern is formed on a ceramic substrate such as alumina or ferrite, a window is provided on the ceramic substrate to insert a coil component, and the wiring pattern is brought into contact with the end face electrodes 5, 6 of the coil component to form a thick film. Since it is fired using the formation process and electrically connected, heat resistance can be improved and a structure corresponding to this thick film formation process can be considered.

Next, the coil component shown in FIG. 4 will be described. The structure shown in FIG. 4 is composed of insulators 1 having different magnetic properties at the top and bottom of the drawing. That is, in FIG. 4, the insulator A1a is made of a non-magnetic material, and the insulator A1a is made lower and the upper side is made insulator B1b with respect to the winding direction of the conductor 2 in the vertical direction of the drawing.
In the case of a magnetic material, the coil component has a smaller inductance value than the case where the insulator 1 is made of a magnetic material, but the DC superposition characteristic can be significantly improved. That is, even if the current value is changed, the change in the inductance value can be reduced, and the allowable current value can be increased.

Further, both the insulator A1a and the insulator B1b are magnetic bodies, and the magnetic flux density is magnetically different, so that the DC superposition characteristic can be improved.

Further, by making both the insulator A1a and the insulator B1b magnetic and have magnetically different magnetic permeability, coil components having the same conductor structure but different inductance values can be obtained. . In this case, there is no particular limitation on the magnitude relationship of the magnetic permeability between the insulator A1a and the insulator B1b.

As described above, the insulator A1a and the insulator B1b
By appropriately selecting the magnetic properties of the above, the inductance value of the coil component can be arbitrarily selected, and the leakage flux or the DC superimposition characteristics can be controlled freely.

Next, the coil components shown in FIGS. 5 to 8 will be described. This coil component basically provides a conductor 2 having a large cross-sectional area to reduce the conductor resistance and can be used for a large current.

First, in the one shown in FIG. 5, all the cross sections of the conductor 2 are triangular, and the cross sectional area is remarkably increased as compared with the flat film-like one. In order to obtain this structure, a stepped step portion is provided on the inner surface of the hollow insulator 1, that is, the inclined surface of the hollow portion 7, and a conductive paste is applied to the step portion and cured, and then sintered. As a result, the conductor 2 having a triangular cross section can be realized.

In the structure shown in FIG. 6, any cross section of the conductor 2 has a rectangular shape to increase the cross-sectional area. To achieve this structure, a step-like step is formed on the inner surface of the hollow insulator 1. To form a conductor 2 having a rectangular cross section by forming a portion and using a die for meshing the triangular conductor paste applied to the inner surface of the insulator 1 and further molding or transfer molding the conductor 2. It can be realized by sintering.

In FIG. 7, the conductor 2 has a circular cross section, and this structure also has a semicircular shape on the inner surface of the hollow insulator 1 as described with reference to FIG. A coil component having a circular conductor 2 can be obtained by forming a concave portion, filling the concave portion with a conductor paste, and then molding the conductor 2 using a mold having a semicircular concave portion.

FIG. 8 shows a conductor 2 having a semicircular cross section, which is a hollow insulator 1.
A coil component having a conductor 2 having a semicircular cross-sectional area can be obtained by providing a semicircular concave portion on the inner surface of the above and sintering the one filled with the conductor paste.

Although circular or semicircular shapes are used in FIGS. 7 and 8, it is needless to say that the shape is not limited to a perfect circle and may be an ellipse or an ellipse. Further, in addition to the rectangular cross section shown in FIG. 6, a polygonal cross section such as a pentagon or a hexagon may be used.

Next, the coil component shown in FIG. 9 will be described. This coil component is configured such that no gap is visible between the turn portions of the conductor 2 when viewed from the large diameter side as the conductor 2, and by adopting this configuration, the magnetic flux that turns around only each turn portion of the conductor 2 is reduced. In addition, the proportion of the conductor 2 in the limited area forming the conductor 2 can be increased, the DC resistance can be reduced, and as a result, a coil component having a large inductance value can be obtained.

Further, as shown in FIG. 10, as the conductor 2,
Although FIG. 1 and FIG. 2 show what is constituted by a circular turn portion, a prismatic column component is originally preferred as a surface mount type coil component, and a rectangular columnar coil component has a rectangular shape. It is composed of parts,
It is possible to form a square-shaped turn portion that fills the outer shape of the coil component. This can be configured by forming the pyramidal hollow portion 7 in the insulator 1 and forming the conductor 2 on the inclined surface of the hollow portion 7.

The rectangular conductor 2 is also shown in FIG.
Although 0 indicates a rectangular three-dimensional spiral winding, it is also possible to have a structure in which each rectangular turn part is in the same plane and is connected to an adjacent turn part at the end or the start end. Is.

As a final example, the coil component shown in FIG. 11 will be described. The conductor shown in FIG. 11 has a conductor structure in which both ends have a large diameter and the middle part has a small diameter, and the conductor 2 has a structure in which two conductors described so far are combined.

This is because there is a possibility that stray capacitances will occur when the turns of the conductor 2 have the same diameter in pairs, but since the turns of the same diameter are located far apart, they occur between them. The stray capacitance generated is almost negligible.

As described in many examples above, on the inner surface of the hollow insulator 1 having a conical or pyramidal hollow portion in the center, that is, on the inclined surface of the hollow portion 7 or on the stepped slope. Since the conductor 2 is formed continuously, unlike the conventional laminated structure, the conductor 2 is easy to produce, the yield can be improved, and the neighboring turn portion is made of the insulator 1.
Since it does not face each other through the, the occurrence of stray capacitance can be suppressed to the minimum, so that it is possible to prevent that the self-resonance frequency becomes small and high attenuation cannot be obtained in a wide band when it is used as a filter. The coil component can be remarkably excellent in performance.

In the above embodiment, only the surface mounting type having the end electrodes 5 and 6 provided at both ends has been described. However, the insulator 1 having the pin terminals planted therein and the end electrodes having the end electrodes are provided. Alternatively, a lead-type coil component in which cap-shaped electrodes having terminals are fitted and coupled to both ends of an insulator can be used.

Next, a method of manufacturing the coil component of the present invention will be described. The coil component manufacturing method of the present invention includes a step of forming a hollow body-shaped insulator having a conical or pyramidal hollow portion provided at the center, and a conical or pyramidal hollow portion provided at the center. At least the step of forming a conductor having a plurality of turns on the inner surface of a hollow body-shaped insulator, the diameter of each turn portion gradually changing from one end to the other end, and at least each turn portion being located in a different plane. It is a method of manufacturing a coil component having the two steps.

As described above, there are various kinds of conductor cross-sectional shapes or conductor winding methods. Basically, as described above, a hollow having a conical or pyramidal hollow portion provided at the center. The step of forming a body-shaped insulator consists of a plurality of turns on the inner surface of a hollow body-shaped insulator with a conical or pyramidal hollow portion provided in the center, and the diameter of each turn portion ranges from one end to the other. The method further includes at least the two steps of forming the conductor so as to be gradually different and at least each turn portion is located in a different plane. Since the conductor is formed on the inclined or stepped inner surface of the hollow insulator, the coil component can be obtained with excellent productivity.

Next, a more detailed method of manufacturing the coil component of the present invention will be described with reference to the drawings.

FIG. 12 is a sectional view showing the method of manufacturing the coil component of the present invention in the order of steps. First, as shown in FIG. 12 (a), a three-dimensional spiral staircase portion is formed on the inner surface of a hollow insulator 1 having a conical or pyramidal hollow portion 7 formed in the center. Insulation having a plurality of turns in the staircase portion, the diameter of each turn portion gradually changing from one end to the other end, and having an inner surface on which the conductor 2 can be formed so that at least each turn portion is located in a different plane. Form body 1.

Even if the shape of the inner surface is a simple conical surface or a pyramidal surface, as described above, the conductor 2 is composed of a plurality of turns, and the diameter of each turn portion gradually changes from one end to the other end, and at least The conductor 2 may be formed on this inner surface so that each turn portion is located in a different plane. On the other hand, in the case of a stepped surface instead of a simple inclined surface, for example, when the conductor 2 is formed at a corner of the stepped surface, the conductor 2 is composed of a plurality of turns as a whole, and the diameter of each turn portion gradually increases from one end to the other end. And the conductor 2 needs to be formed so that at least each turn portion is located in a different plane.

As a more specific example of the conductor 2, as described above, each turn portion of the conductor 2 is formed in the same plane from one end to the other end, and the turn portions adjacent to each other at the end or the start end of each turn portion. There is a three-dimensional spiral-shaped conductor connected from one end to the other end.

As a method for forming the hollow-body-shaped insulator 1 having the inner surface having the above-described shape, the slurry-shaped insulator 1 is poured onto a support having convex portions capable of engaging with the inner surface, and after drying, By separating from this support, a specific hollow portion 7 can be formed in the insulator 1. As another method, in the same manner as described above, a slurry-like insulator 1 is poured onto a flat support to form a smooth sheet-like insulator 1 and then the predetermined hollow portion 7 is formed. This is a method of forming a specific hollow portion 7 in the insulator 1 with a mold having a shape. Further, the hollow-body-shaped insulator 1 having the specific hollow portion 7 can be similarly formed by a generally known powder molding method. By either method, as shown in FIG. 12A, the hollow insulator 1 having the above-described specific inner surface can be formed. Moreover, as described above, the inner surface may be either a slope or a step-like slope.

Next, as shown in FIG. 12B, the conductor 2 is formed on the inner surface of the insulator 1 having the specific hollow portion 7 in the spiral step shape of this hollow portion 7. The conductor 2 is composed of a plurality of turns, and the diameter of each turn portion gradually changes from one end to the other end, and at least each turn portion is located in a different plane. As described above, as described above, there is a shape in which the central portion of the mosquito coil incense-shaped conductor 2 is pulled down to form a trumpet shape or a concentric circle shape.

The insulator 1 on which the conductor 2 is formed is shown in FIG.
As shown in FIG. 3, the lead-out portion 3 joined to the conductor end portion of the conductor 2 on the smaller conductor diameter side is formed on the bottom surface of the insulator 1. FIG.
Similarly, as shown in (d), a lead-out portion 4 is formed on the bottom surface of the insulator 1 and on the opposite surface on which the lead-out portion 3 is formed.

Further, as shown in FIG. 12E, end face electrodes 5 and 6 are formed on the two surfaces of the chip-shaped component. By firing the obtained laminate, a coil component can be obtained. However, the firing is performed on the end electrodes 5 and 6
May be performed without forming. That is, the end surface electrodes 5 and 6 not formed are fired, and the end surface electrodes 5 are fired after firing.
And 6 is a method of forming. An example of the forming method in this case will be described. A conductor layer is formed in the same shape as the end face electrode shown in FIG. 12, and is fired once. Thereafter, using this conductor layer as an electrode, nickel plating and solder or tin plating are performed. Finally, the end electrodes 5 and 6 have a three-layer structure of nickel and solder or tin formed by electroplating and an underlying conductor layer formed by firing.

The insulator 1 described above can be formed by a generally known green sheet molding method, printing method, dipping method, powder molding method, spin coating method, or the like. The conductor 2 or the lead portions 3 and 4 are generally printed by a printing method, but a method of forming a pattern by using a laser, a method of transferring a conductor previously formed in a predetermined shape with a mold, a dropping method, a potting method, or a spraying method. But it's okay.

The coil component obtained by the manufacturing method of the present invention is a coil component having excellent heat resistance, and thus can be easily modularized. For example, a predetermined wiring layer may be formed on a ceramic substrate such as an alumina substrate or a ferrite substrate, and wiring of the substrate and wiring of the end surface electrodes 5 to 6 of the coil component may be simultaneously performed to integrate or assemble them. In this case, a thin module can be obtained because it is possible to open a window at a predetermined position on the substrate and connect the end face electrodes 5 to 6 on the side surface of the coil component and the wiring on the ceramic substrate. In this case, an ordinary thick film forming process using a generally known ceramic substrate can be applied. The end face electrodes 5 to 6 of the coil component are not based on the assumption of soldering, but may be fired to be electrically connected.

The two terminals of the conductor 2 forming the above coil are formed on the end face of the chip part and end face electrodes 5 to 6 are formed.
It is in a state of being electrically connected to. That is, the uppermost and lowermost portions of the conductor 2 have the lead-out portions 3 to 4 for electrically connecting with the end face electrodes 5 to 6, and are connected to the end face electrodes 5 to 6.

The paste for forming the above layers is
Solvents such as butyl carbitol, terpineol, and alcohol, binders such as ethyl cellulose, polyvinyl butyral, polyvinyl alcohol, polyethylene oxide, and ethylene-vinyl acetate; and sintering aids such as various oxides and glasses. In addition, a plasticizer or a dispersant such as butylbenzyl phthalate, dibutyl phthalate, and glycerin may be added.
Each layer is formed using a kneaded material obtained by mixing these. A coil component is obtained by firing a laminate of these in a predetermined structure as described above. When producing a green sheet, various solvents having excellent evaporating properties, for example, butyl acetate, methyl ethyl ketone, toluene, alcohol, and the like are desirable in place of the above-mentioned solvents.

The firing temperature range is about 800 ° C. to 13
It is in the range of 00 ° C. In particular, it depends on the conductor material. For example, when silver is used as the conductor material, it is necessary to be around 900 ° C., and at 950 ° C. for an alloy of silver and palladium, and nickel or palladium is used as the conductor material for firing at a higher temperature. .

Next, more specific examples of the present invention will be described. (Example 1) 8 g of butyral resin, 4 g of butylbenzyl phthalate, 24 g of methyl ethyl ketone and 24 g of butyl acetate were mixed with 100 g of NiZnCu-based ferrite powder and kneaded with a pot mill to prepare a ferrite slurry.

Using this slurry, a ferrite green sheet having a thickness of 0.2 mm was prepared by using a coater and drying. The green sheet was formed on a PET film.

Five pieces of this ferrite green sheet were stacked and laminated. A hot press was used for lamination of the ferrite green sheets, the platen temperature of the hot press was set to 100 ° C., and the pressure was 500 kg / cm ² . Using a die having a shape for forming a specific inner surface as shown in FIG. 12 (a) and a puncher capable of forming holes using this die, the laminated ferrite green sheet is specified. The hollow portion 7 having the inner surface of was formed.

Next, as shown in FIG. 12B, a conductor 2 was formed on a specific inner surface of the ferrite green sheet using a commercially available silver paste and a printing machine. The printing method was carried out in the same manner as in generally known through-hole printing, by sucking from the surface opposite to the printing surface of the ferrite green sheet so that the silver paste was left on the stepped corner of the specific inner surface.

Next, as shown in FIG. 12C, the insulator 1
The lead-out portion 3 was formed on the bottom surface of the same using the same silver paste as above and a printing machine. Furthermore, as shown in FIG. 12D, the lead-out portion 4 was similarly formed on the bottom surface of the insulator 1.

Further, end face electrodes 5 and 6 as shown in FIG. 12E are formed by using a commercially available silver paste, and the temperature is set to 900 ° C.
Firing for 2 hours.

No defects such as peeling, cracking, or warpage were found in the coil component of the present invention obtained by the above method.

Using an impedance analyzer or the like,
When various electric characteristics were measured, it was a coil component having excellent characteristics.

As described above, the coil component of the present invention can provide a coil component having excellent productivity and excellent productivity as compared with the conventional laminated coil component.

(Example 2) NiZnC as in Example 1
6 g of butyral resin, 4 g of butylbenzyl phthalate and 50 g of butyl acetate were mixed with 100 g of the u-based ferrite powder, and the mixture was kneaded using a pot mill to prepare a ferrite slurry.

Using this slurry, using a coater on a sheet-shaped polyimide having a predetermined convex portion to form a hollow portion 7 having a specific inner surface as shown in FIG. A ferrite green sheet having a thickness of 0.8 mm was produced.

In the same manner as in Example 1, the conductor 2 was formed on a specific inner surface of the ferrite green sheet as shown in FIG. 12B by using a commercially available silver paste and a printing machine. The printing method was carried out in the same manner as in generally known through-hole printing, by sucking from the surface opposite to the printing surface of the ferrite green sheet so that the silver paste was left on the stepped corner of the specific inner surface.

Next, as shown in FIG. 12C, the insulator 1
The lead-out portion 3 was formed on the bottom surface of the same using the same silver paste as above and a printing machine. Furthermore, as shown in FIG. 12D, the lead-out portion 4 was similarly formed on the bottom surface of the insulator 1.

Further, end face electrodes 5 and 6 as shown in FIG. 12E are formed by using a commercially available silver paste, and the temperature is set to 900 ° C.
Firing for 2 hours.

No defects such as peeling, cracking or warpage were found in the coil component of the present invention obtained by the above method.

Using an impedance analyzer or the like,
When various electric characteristics were measured, it was a coil component having excellent characteristics.

As described above, the coil component of the present invention can provide a coil component having excellent productivity and excellent electrical characteristics as compared with the conventional laminated coil component. Further, this method is more advantageous than the method shown in Example 1 in terms of man-hours since it has no step of forming a specific inner surface.

[0086]

As is apparent from the above description, the coil component of the present invention is not a laminated structure and thus has excellent productivity, and is a hollow body-shaped insulation having a conical or pyramidal hollow portion provided in the center. Since the conductor is located on the inner surface of the body, the slope or the step-like slope, the height can be kept low, and the stray capacitance between the turn parts of the conductor hardly occurs, and the electrical characteristics are excellent. It is of great industrial value.

[Brief description of the drawings]

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

FIG. 2 is a schematic perspective view of another embodiment.

FIG. 3 is a sectional view of the same.

FIG. 4 is a cross-sectional view of another embodiment.

FIG. 5 is a sectional view of still another embodiment.

FIG. 6 is a sectional view of still another embodiment.

FIG. 7 is a sectional view of still another embodiment.

FIG. 8 is a sectional view of still another embodiment.

FIG. 9 is a sectional view of still another embodiment.

FIG. 10 is a schematic perspective view showing still another embodiment.

FIG. 11 is a sectional view of still another embodiment.

12 (a) to (e) are schematic cross-sectional views showing a method for manufacturing a coil component of the present invention.

FIG. 13 is a schematic perspective view showing a conventional coil component.

FIG. 14 is an exploded perspective view of the same.

[Explanation of symbols]

 1 Insulator 1a Insulator A 1b Insulator B 2 Conductor 3,4 Lead-out part 5,6 End face electrode 7 Hollow part

Claims (18)

[Claims] 1. A conductor having a plurality of turns is provided on the inner surface of a hollow body-shaped insulator having a conical or pyramidal hollow portion provided at the center, and the diameter of each turn portion of the conductor is from one end to the other end. A coil component that is gradually different and is configured such that at least each turn portion is located in a different plane. 2. A structure in which each turn portion of the conductor is formed in the same plane from one end to the other end and is connected to an adjacent turn portion at a terminal end or a starting end of each turn portion.
Described coil parts. 3. The coil component according to claim 1, wherein the conductor has a three-dimensional spiral shape from one end to the other end. 4. The coil component according to claim 1, wherein each of the turns of the conductor has a circular shape. 5. The coil component according to claim 1, wherein each of the turns of the conductor has a rectangular shape. 6. The coil component according to claim 1, wherein the conductors are formed such that the conductor gaps are not visible between the turn portions when viewed from the large diameter turn portion side. 7. The coil component according to claim 1, wherein the cross-sectional shape of the conductor is rectangular, circular or semicircular. 8. The coil component according to claim 1, wherein the insulator is a non-magnetic substance. 9. The coil component according to claim 1, wherein the insulator is a magnetic substance. 10. The coil component according to claim 1, wherein the insulator is composed of two or more kinds having different magnetic properties. 11. The coil component according to claim 10, wherein a non-magnetic material and a magnetic material are used as those having different magnetic properties. 12. The coil component according to claim 1, further comprising an end face electrode layer electrically connected to one end or the other end of the conductor on the surface of the insulator. 13. A step of forming a hollow insulator having a conical or pyramidal hollow at the center, and a plurality of turns formed on the inner surface of the hollow insulator so that each turn has a diameter of A method for manufacturing a coil component, comprising a step of forming conductors such that the conductors are gradually different from one end to the other and at least respective turn portions are located in different planes. 14. The step of forming a hollow body-shaped insulator having a conical or pyramidal hollow portion provided at the center comprises forming a convex portion for forming the conical or pyramidal hollow portion on the insulator. 14. The method for manufacturing a coil component according to claim 13, which is a step of forming an insulator having a slanted inner surface of a hollow body provided with a hollow portion having a conical shape or a pyramidal shape by pouring the insulating slurry on the supporting body. 15. The step of forming a hollow body-shaped insulator having a cone-shaped or pyramidal-shaped hollow portion provided in the center has a step of forming a convex portion for forming the cone-shaped or pyramidal-shaped hollow portion in the insulator. 14. The method for manufacturing a coil component according to claim 13, which is a step of forming an insulator having a stepped surface on the inner surface of a hollow body having a conical or pyramidal hollow portion provided by pouring the insulator slurry on the support body. .. 16. The step of forming a hollow-body-shaped insulator having a conical or pyramidal-shaped hollow portion provided in the center thereof includes the step of forming a flat sheet-shaped insulator, and the conical or pyramidal shape. 14. The method for manufacturing a coil component according to claim 13, further comprising the step of forming the hollow portion in the center of the insulator. 17. A mold having a convex portion having an inclined surface for forming a conical or pyramidal hollow portion in the insulator in the step of forming a conical or pyramidal hollow portion in the center of the insulator. 17. The method for manufacturing a coil component according to claim 16, which is a step of molding an insulator with. 18. The step of forming a conical or pyramidal hollow portion in the center of an insulator comprises forming a convex portion having a step-like slope for forming the conical or pyramidal hollow portion in the insulator. 17. The method for manufacturing a coil component according to claim 16, which is a step of molding an insulator with a mold that the user has.