JP2004096872A - Laminated coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated coil for a motor capable of realizing size and thickness reductions and little deformation. <P>SOLUTION: This laminated coil is a coil for the rectangular motor integrated with a plurality of coil poles which consist of coils formed at a laminate formed by laminating an insulating layer with a conductor pattern, and an input terminal electrode and an output terminal electrode formed at an external surface of the laminate and connected with the coil poles. The input terminal pole and the output terminal pole are formed at a corner of one main surface of the laminate which does not substantially overlap in the laminating direction with the coil poles. A deformation restraining electrode pattern is formed which does not overlap in the laminating direction with coil poles on the other main surface of the laminate but which overlaps in the laminating direction with the input terminal pole and the output terminal pole. <P>COPYRIGHT: (C)2004,JPO

Description

【００１８】
表１で示した層構成を有する積層コイルの変形（反り量）を評価した。評価方法は、レーザ光線を利用して測定物の高さを非接触で測定することが出来る３次元ＣＮＣ画像測定器を用い、積層コイルの入力、出力端子電極が形成された主面側を縁部と平行に１００μｍピッチで掃引して８０×８０点（６４００点）測定し、その最大値と最小値の差を被測定物の反り量とした。これを各試料毎に１０枚づつ測定して各試料の反り量を平均値、最大値、最小値として表２に示す。実装基板に積層コイルを直接搭載する場合には、その反り量を１５０μｍ以下とするのが好ましいが、本発明の実施例においてはすべて１５０μｍ以下の反り量とすることが出来た。
【００１９】
【表２】

【００２０】
【発明の効果】
本発明によれば、小型・薄型でかつ変形の小さい積層コイルを得る事が出来る。
【図面の簡単な説明】
【図１】本発明の一実施例に係る積層コイルの斜視図である。
【図２】本発明の一実施例に係る積層コイルの内部構造を示す分解図である。
【図３】本発明の一実施例に係る積層コイルの等価回路である。
【図４】本発明の一実施例に係る積層コイルのコイル接続状態を示す内部構造分解図である。
【図５】本発明の他の実施例に係る積層コイルの斜視図である。
【図６】本発明に係る積層コイルの製造方法の一例を示す積層基板の分解斜視図である。
【図７】本発明に係る積層コイルが複数形成された積層基板の平面図である。
【図８】本発明の一実施例に係る積層コイルを用いたブラシレスモータの断面図である
【図９】従来の積層コイルの分解斜視図である。
【符号の説明】
１　積層コイル
１０　貫通孔
６０　第１のコイル極
６１　第２のコイル極
６２　第３のコイル極
２００、２０１ａ、２０１ｂ、２０１ｃ、２１０　第１の接続線路
２５１ａ〜２５１ｈ、２５２ａ〜２５２ｈ、２５３ａ〜２５３ｈ　コイル
３００ａ〜３００ｃ　第２のコイル
３１０ａ〜３１０ｃ　変形抑止電極パターン[0001]
[Industrial applications]
The present invention relates to a laminated coil for a motor that is small, thin, and has little deformation.
[0002]
As electronic devices become smaller, there is a strong demand for smaller and thinner motors used in each electronic device. As such a motor, for example, JP-A-64-59902 discloses that a coil conductor pattern is formed on a green sheet obtained from ceramic powder by, for example, a screen printing technique to form a coil sheet. A laminated coil for a brushless motor is disclosed in which through-holes conduct between coil conductor patterns and furthermore, the coil conductor patterns and the green sheets are integrally fired. FIG. 9 shows an exploded perspective view thereof.
[0003]
[Problems to be solved by the invention]
In such a conventional coil, a plurality of coil sheets 61a and 61b are laminated on a green sheet substrate 60 on which external terminal electrodes are formed. After lamination, the thickness of the circular portion where the coil is formed is different from the thickness of the rectangular portion where the external terminal electrodes are formed, making it difficult to manufacture, and the shape of the laminated coil is poor in productivity. Further, in order to obtain the mechanical strength of the external terminal electrode portion 65, it is necessary to make the green sheet 60 substrate on which the coil conductor pattern is not formed thick, and as a result, the thickness of the laminated coil increases, and the external terminal electrode There is a problem that the portion 65 increases the area of the laminated coil, and as a result, the outer dimensions of the brushless motor increase.
[0004]
The coil conductor pattern is made of Ag, Cu or the like, and the green sheet is a low-temperature sinterable ceramic material containing, for example, Al ₂ O ₃ as a main component. I have. Such a green sheet and a coil conductor pattern have a large sintering shrinkage ratio and different shrinkage characteristics. Generally, when a green sheet and a conductor pattern formed on the surface of the green sheet are integrally fired, the conductor constituting the conductor pattern, such as Ag or Cu, starts to contract from the time when the glass transition point is reached. Subsequently, the ceramic of the green sheet starts shrinking when the glass transition point is reached.
As described above, the contraction precedes the conductor pattern. When the conductor suppresses the crystallization peak point, the contraction is almost completed. On the other hand, the ceramic has a crystallization peak point higher than that of the conductor, and thus contracts continuously.
The ceramic used for the laminated coil contains a component that easily becomes glass during sintering or a component that easily forms a liquid phase so that sintering can be performed at a relatively low temperature. As the densification progresses, the ceramic itself becomes softer and deforms due to uneven distribution of stress in the laminated coil during sintering due to the difference in shrinkage characteristics between the ceramic and the conductor pattern.
In particular, if the arrangement of the conductor patterns in the laminated coil is asymmetrical in the laminating direction, if the conductor patterns are formed asymmetrically in the laminating direction, shrinkage and concentration of the side where the conductor patterns are concentrated are likely to occur. There was a difference in shrinkage on the non-existing side, resulting in deformation.
Therefore, an object of the present invention is to provide a laminated coil that is small, thin, and small in deformation.
[0005]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided an input terminal electrode connected to a plurality of coil poles formed of a coil formed of a conductor pattern on a laminate obtained by laminating insulator layers, and the coil poles formed on an outer surface of the laminate. A rectangular laminated coil in which an output terminal electrode and an output terminal electrode are integrated, wherein the input terminal electrode and the output terminal electrode are formed at corners on one main surface of the laminate that do not substantially overlap with the coil electrode in the laminating direction. And a deformation preventing electrode pattern which does not overlap with the coil pole in the stacking direction but overlaps with the input terminal electrode and the output terminal electrode in the stacking direction on the other main surface of the stack. .
It is preferable that the deformation suppressing electrode pattern has an approximate shape to the input terminal electrode and the output terminal electrode. In the present invention, deformation is suppressed by arranging the conductor patterns formed on the laminated coil symmetrically in the laminating direction.
Also, on one main surface of the rectangular laminated coil, if the input terminal and the output terminal are formed at four different corners of the main surface so as not to overlap with the coil pole in the laminating direction, the laminated coil is not substantially enlarged. A laminated coil can be configured. Furthermore, since the input / output terminals can be formed relatively large, the terminal connection strength with the printed circuit board can be improved, and the empty space of the laminated coil where the coil pole is not formed can be used effectively.
Since the input terminal electrodes and the output terminal electrodes are formed on the same main surface of the laminated coil, the connection with the printed circuit board (PCB) is easily surface-mounted. The input terminal electrode and the output terminal electrode are preferably LGA (Land Grid Array) and BGA (Ball Grid Array), respectively.
In the present invention, if the input terminal electrode and the output terminal electrode are connected to the deformation suppressing electrode pattern by a through hole or a side electrode formed in a laminate, surface mounting can be performed on both main surfaces of the laminated coil. Is preferable. Further, if the side surface electrode is formed, the solder can also flow around the portion to make the connection stronger.
[0006]
A plurality of coil poles formed of a spiral coil formed of a conductor pattern on a laminate formed by laminating insulator layers; and input terminal electrodes and output terminal electrodes formed on one main surface of the laminate and connected to the coil poles A laminated coil having a thickness of A between the spiral coils, and a first coil between the spiral coil and a main surface on which the input terminal electrode and the output terminal electrode are formed. When the thickness of the insulator layer in the unformed region is B and the thickness of the insulating layer in the second coil non-formed region between the other main surface of the laminated coil and the spiral coil is C, the thickness of the first conductor pattern non-formed region is The ratio of the insulator layer thickness B to the insulator layer thickness A between the spiral coils is 1 ≦ (B / A) ≦ 10, and the insulation between the insulator layer thickness C in the second coil-free area and the spiral coil Body layer thickness A The ratio is 1 ≦ (C / A) ≦ 10 is an insulator layer thickness C and the insulator layer thickness B is substantially equal laminated coil.
In the present invention, the input terminal electrode and the output terminal electrode are formed at a corner on one main surface of the laminate that does not substantially overlap with the coil pole in the laminating direction, and on another main surface of the laminate. It is preferable to form a deformation suppressing electrode pattern that does not overlap with the coil pole in the stacking direction but overlaps with the input terminal electrode and the output terminal electrode in the stacking direction.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a laminated coil according to an embodiment of the present invention will be described.
FIG. 1 is a perspective view of a laminated coil according to an embodiment of the present invention. This laminated coil is formed by printing a conductive paste mainly composed of Ag, Cu, or the like on a green sheet having a thickness of several μm to 200 μm made of a ceramic material (LTCC material) that can be fired at a low temperature. Are formed, green sheets having a conductor pattern are appropriately laminated, and fired to integrate a plurality of coil poles. It is preferable to use a green sheet for forming the coil having a thickness of 20 μm or less in order to increase the space factor.
The laminated coil is formed in a rectangular plate shape, and has an input terminal electrode IN for connection between the coil pole and an external circuit and output terminal electrodes OUT1 to 3 on its main surface, and the input terminal electrode OUT1 to 3 on its other main surface. Deformation suppressing electrode patterns 310a to 310d are formed so as to have an approximate shape to the output terminal electrodes and to overlap the input / output terminal electrodes in the laminating direction. The input terminal electrode IN and the output terminal electrodes OUT1 to OUT3 are formed at the four corners of the rectangular laminated coil so as not to overlap with the coil pole included in the laminated coil in the laminating direction. Although the shape is not particularly limited, it is preferably formed as large as possible from the viewpoint of securing the soldering strength with the mounting board. In this embodiment, the electrode pattern is formed as a substantially triangular electrode pattern. Then, the deformation suppressing electrode pattern overlaps with the input terminal electrode and the output terminal electrode and is formed in an approximate shape with the input terminal electrode and the output terminal electrode so as to configure the laminated coil with good symmetry. The electrode thickness is preferably formed in the same manner as the input terminal electrode and the output terminal electrode, and the thickness is 8 to 25 μm. In the present embodiment, the deformation suppressing electrode pattern is formed only on the main surface of the laminated coil, but may be included in the laminated coil similarly to the coil. It is preferable that the deformation suppressing electrode pattern and the input terminal electrode and the output terminal electrode are electrically connected to each other by a through hole included in the laminated coil or a side electrode formed on a side surface. FIG. 5 shows castellations formed at the four corners of the laminated coil, and side electrodes extending from the main surface on which the input terminal electrodes and the output terminal electrodes are formed to the other main surface on which the deformation suppressing electrode pattern is formed. Is formed. With such a configuration, the surface to be mounted on the mounting substrate can be appropriately selected, and if side electrodes are provided, the soldering can be made stronger. Further, the deformation suppressing electrode pattern does not necessarily have to have an approximate shape to the input terminal electrode and the output terminal electrode, and the shape for suppressing the deformation may be appropriately set according to the laminated coil.
[0008]
In the laminated coil according to the present invention, the thickness of the insulator layer between the spiral coils is A, and the insulation of the first coil non-formed region between the spiral coil and the main surface on which the input terminal electrode and the output terminal electrode are formed is provided. When the thickness of the body layer is B and the thickness of the insulating layer in the second coil non-formed area between the other main surface of the laminated coil and the spiral coil is C, the thickness of the insulating layer in the first conductive pattern unformed area is B And the ratio of the insulator layer thickness A between the spiral coils is 1 ≦ (B / A) ≦ 10, and the insulator layer thickness C in the region where the second coil is not formed and the insulator layer thickness A between the spiral coils are: Is preferably 1 ≦ (C / A) ≦ 10, and the insulator layer thickness B and the insulator layer thickness C are preferably substantially equal. If the thickness of the insulator layer in the first coil non-formed area is different from the thickness of the insulator layer in the second coil non-formed area, the symmetry of the electrode pattern in the laminated coil is impaired and the amount of deformation is undesirably increased. . The thicknesses B and C of the insulator layer in the first coil non-formation area and the insulation layer in the second coil non-formation area are not less than the thickness A of the insulator between the spiral coils and not more than 10 times the thickness A. It is preferable that the thickness is If the thickness of the insulating layer in the area where the coil is not formed is smaller than the thickness of the insulating layer between the spiral coils, sufficient pressure cannot be applied to the laminated coil during crimping, causing structural defects such as delamination. However, forcible pressure bonding is not preferable because deformation and disconnection of the coil and cracks and the like occur in the insulator layer between the coils. Further, even if the laminated coil is formed thicker than 10 times the insulator layer thickness A, the laminated coil simply becomes thicker. If the laminated coil has a predetermined thickness, the number of insulator layers forming the coil must be reduced. As a result, the number of coil turns is reduced, and desired torque characteristics cannot be obtained.
[0009]
An example of a method for manufacturing a laminated coil according to the present invention will be described with reference to FIGS. First, by a known sheet forming method such as a doctor blade method, a ceramic slurry composed of a ceramic powder, a binder, and a plasticizer is applied on a carrier film composed of a polyethylene terephthalate film in a uniform thickness, and several tens μm to several hundreds. A green sheet of μm is formed. Then, the dried green sheet is cut into a predetermined size with the carrier sheet attached. The ceramic powder is, for example, a dielectric material which can be sintered at a low temperature and contains at least one of SiO ₂ , SrO, CaO, PbO, Na ₂ O, and K ₂ O as a main component, which is mainly composed of Al ₂ O ₃ , Another example is a low-temperature sinterable dielectric material containing Al ₂ O ₃ as a main component and at least one of MgO, SiO ₂ and GdO as a multiple component. In still another example, the magnetic ceramic material is a low-temperature sinterable magnetic ceramic material including at least one of Bi ₂ O ₃ , Y ₂ O ₃ , CaCO ₃ , Fe ₂ O ₃ , In ₂ O ₃ and V ₂ O _5. In addition, ceramic components are devised for low-temperature sintering.
In this embodiment, the main component is composed of oxides of Al, Si, Sr, and Ti, and Al, Si, Sr, and Ti are converted to Al ₂ O ₃ , SiO ₂ , SrO, and TiO ₂ , respectively, for a total of 100 mass. % and the time, 10 to 60 wt% in terms _{of Al} 2 _{O 3,} 25 to 60 wt% in terms of SiO _2, from 7.5 to 50 mass% in terms of SrO, TiO ₂ converted at 20 wt% or less of Al, Si , Sr, containing Ti, as an accessory component relative to the total 100 wt%, using dielectric ceramics containing Bi of 0.1 to 10 mass% in terms _{of Bi} 2 _{O 3.} The basic characteristics of this dielectric ceramic are that the dielectric constant is 7 to 9 and the three-point bending (sample shape 36 mm, width 4 mm, thickness 3 mm, distance between fulcrums) according to the bending strength test method specified in JIS R 1601 (30 mm), the flexural strength is 240 MPa or more, the Young's modulus is 110 GPa or more, and the LTCC material has high flexural strength and Young's modulus.
[0010]
A coil (not shown), an input / output terminal, and the like, which will be described later, are formed by a conductor pattern on such a green sheet, and are laminated and crimped in a predetermined order to obtain a flat laminate 300 having a thickness of approximately 0.4 mm. . A main surface opposite to the main surface on which the input terminals IN, the output terminals OUT1, OUT2, OUT3, and the conductor patterns 210, 201a, 201b, 201c for connecting the input terminals to the coil poles are formed. The electrode patterns 310a, 310b, 310c, and 310d, which do not overlap with the coil poles in the stacking direction but overlap with the input terminal electrodes and the output terminal electrodes in the stacking direction, have substantially the same shape by printing or transferring a conductive paste. Formed. Further, second connection lines 300a, 300b, 300c for connecting in-phase coil poles in series are formed on the same surface. A through hole (not shown) is formed in the green sheet, and a conductor pattern between the sheets is appropriately connected, so that the green sheet functions as a coil pole.
Thereafter, a portion of the laminate, which is to be the rotation center of the motor rotation shaft, was punched out by a die or laser-processed to form a through hole 10 having a diameter of 2 mm.
Then, a plurality of divided grooves parallel to each other and a plurality of divided grooves 320 orthogonal to the divided grooves 320 were engraved on the main surface of the plate-shaped laminate with a steel blade so as to have a depth of approximately 0.1 mm. The depth of the division groove is appropriately set in the range of 50 μm to 300 μm from the viewpoint of easy division and easy handling. Thereafter, the flat molded body was degreased and sintered to obtain a laminated substrate 300 (assembly of laminated coils) of 65 mm × 60 mm × 0.3 mm. On the outer surface of the multilayer substrate 300, input / output terminals of a multilayer coil and the like are formed, and Ni plating and Au plating are applied to the input terminal by electroless plating. After the plating treatment, the coil was divided along the dividing groove to obtain a laminated coil 1 for a brushless motor having an outer dimension of 8 mm × 8 mm × 0.3 mm shown in FIG.
[0011]
Next, the internal structure of the laminated coil according to one embodiment of the present invention will be described in detail in the order of lamination with reference to FIG. This laminated coil is a laminated coil for a brushless motor using a three-phase drive power supply, and has an equivalent circuit shown in FIG.
First, second connection lines 300a, 300b, and 300c for connecting in-phase coil poles are formed on the back surface of the lowermost first layer. These second connection lines are arranged at equal angular intervals around a motor rotation axis, which will be described later, and have two arc-shaped portions centered on the motor rotation axis, and the second connection lines formed radially from the motor rotation axis center. And a radial portion connecting the two arc-shaped portions.
In the present embodiment, the second connection line is configured as described above to connect the in-phase coil poles arranged at rotationally symmetric positions at 180 ° to the rotation center of the motor rotation shaft. By arranging the two arc-shaped portions on the circumference around the motor rotation axis, the torque characteristics can be slightly improved without hindering the rotation characteristics of the motor. Although the second connection line is formed outside the laminate, the second connection line may be formed by printing a conductive paste inside the laminate similarly to the coil pole.
Then, triangular deformation suppressing conductor patterns 310a, 310b, 310c, 310d are formed at four corners of the main surface of the laminated coil. These electrode patterns are formed at portions overlapping the input terminal electrodes and the output terminal electrodes formed on the other main surface in the laminating direction, and have an approximate shape to the input terminal electrodes and the output terminal electrodes.
[0012]
A plurality of coils are formed on the first layer. The coils are arranged at equal angular intervals around the motor rotation axis to form a multi-phase coil pole. In the plurality of coils formed on the first layer, six coils 251 g, 252 g, 253 g, 251 h, 252 h, and 253 h serving as three-phase coil poles are formed on the same layer at intervals of 60 °.
The first coil 251h is wound clockwise from the inner peripheral side to the outer peripheral side and has a through-hole portion (indicated by a black circle in the drawing) at an outer peripheral end portion for connection to a coil of another layer. 252h, 253h, and second coils 251g, 252g, 253g, which are wound clockwise from the outer peripheral side to the inner peripheral side and have through-holes formed at the inner peripheral end for connection with coils of other layers. Be composed. The first coil and the second coil are alternately arranged around the motor rotation axis as shown.
In the present embodiment, the coil located at a rotationally symmetric position of 180 ° with respect to the motor rotation axis is electrically connected in series by the second connection line and becomes a coil pole of the same phase. That is, the first coil 251h and the second coil 251g are connected by the second connection line 300a, the first coil 252h and the second coil 252g are connected by the second connection line 300b, and the first coil 253h And the second coil 253g are connected by the second connection line 300c, and form coil poles of different phases. That is, the connection line 300a is at the midpoint of the second phase coil pole 61 shown in FIG. 3, the connection line 300b is at the midpoint of the first phase coil pole 60, and the connection line 300c is at the midpoint of the third phase coil pole 62 shown in FIG. It constitutes each middle point.
[0013]
A second layer on which a plurality of coils are formed is disposed above the first layer. The plurality of coils include six coils 251e, 252e, 253e, 251f, 252f, and 253f that are three-phase coil poles formed around the motor rotation axis and are formed on the same layer at 60 ° intervals, and each has four turns. The spiral coil is turned. Here, if the coil formed on the first layer is the first coil wound clockwise from the inner peripheral side to the outer peripheral side, the coil formed on the second layer overlapping the coil in the laminating direction Is formed as a second coil wound clockwise from the outer peripheral side to the inner peripheral side, and if the coil formed on the first layer is the second coil, the second coil is disposed above the second coil. A first coil is formed on the two layers, and each is connected by a through hole and connected in the same winding direction.
[0014]
The third layer has substantially the same structure as the first layer, and the fourth layer has substantially the same structure as the second layer. The in-phase spiral coils formed in the first to fourth layers and overlapping in the laminating direction include a first coil wound clockwise from an inner peripheral side to an outer peripheral side, and an outer peripheral end of the first coil. The second coil is connected and wound in a clockwise direction from the outer side to the inner side and has the same winding direction. Therefore, the current flows in the first coil and the second coil in a fixed direction. Operate as one coil pole to which is applied. In the present embodiment, the number of turns of the coil pole is increased, and one coil is wound four turns so as to increase the torque of the motor. By connecting, the number of turns of the coil per phase is 32 turns. The number of turns of the coil can be easily adjusted by increasing or decreasing the number of layers of each layer on which the coil is formed. As described above, the coils were arranged symmetrically in the laminating direction so that the difference in shrinkage was minimized.
[0015]
The same conductive paste as that used to form the coil is printed on the fifth layer laminated thereon to form a first connection line that connects the input terminal electrode IN, the output terminal electrodes OUT1 to OUT3, and the coil pole. Was formed. The first connection line includes an annular conductor portion 210 formed so as to surround a through hole 10 formed at a substantially central portion of the multilayer body, and a first conductor for connecting the annular conductor portion to an input terminal. It comprises a portion 200 and second conductor portions 201a to 201c extending from the annular conductor portion 210 and connecting to coil poles.
In this way, as shown in FIG. 4 by a two-dot dashed line, the connection state between the coils, the first-phase coil pole 60 disposed between the input terminal IN and the output terminal OUT1 is formed by the coils 252a to 252h. The second phase coil pole 61 disposed between the terminal IN and the output terminal OUT2 is formed by the coils 251a to 251h, and the third phase coil pole 62 disposed between the input terminal IN and the output terminal OUT3 is formed by the coils 253a to 253h. 253 h.
The center of the through-hole 10 formed substantially at the center of the laminate substantially coincides with the center of the axis of the rotor. The through-hole 10 is formed by punching a laminate with a mold, laser processing, or the like.
As described above, a laminated coil for a brushless motor of 8 mm × 8 mm × 0.3 mm was prepared. It is also within the scope of the present invention to form a coat layer on the main surface of the laminated coil with overcoat glass.
[0016]
Through the above-described steps, a laminated coil having the layer configuration shown in Table 1 was produced. In all of the laminated coils shown here, the thickness of the insulator layer between the spiral coils is 20 μm in terms of the thickness of the green sheet. Note that all thicknesses in the table are shown as grease sheet thicknesses. Sample No. Reference numeral 1 denotes a comparative example of the present invention in which the first coil pattern non-formation region thickness A and the second coil pattern non-formation thickness B are different from each other and has no deformation suppression electrode pattern. Is attached. Sample No. Sample No. 2 has a lamination structure of Sample No. Sample No. 1 was the same as Sample No. 1 except that the deformation suppressing electrode pattern was formed on the main surface of the laminated coil. Sample No. 3 is an embodiment of the present invention in which the first coil pattern non-formed region thickness A and the second coil pattern non-formed thickness B are equal and has no deformation suppressing electrode pattern. Sample No. 4 has a lamination structure of Sample No. This is an embodiment similar to Example 3, except that a deformation suppressing electrode pattern is formed on the main surface of the laminated coil.
[0017]
[Table 1]

[0018]
The deformation (warpage) of the laminated coil having the layer configuration shown in Table 1 was evaluated. The evaluation method uses a three-dimensional CNC image measuring device that can measure the height of the object without contact using a laser beam, and rims the main surface side of the laminated coil where the input and output terminal electrodes are formed. The measurement was performed at 80 × 80 points (6400 points) by sweeping at a pitch of 100 μm in parallel with the portion, and the difference between the maximum value and the minimum value was defined as the amount of warpage of the measured object. This is measured for each of the ten samples, and the amount of warpage of each sample is shown in Table 2 as an average value, a maximum value, and a minimum value. When the laminated coil is directly mounted on the mounting substrate, the amount of warpage is preferably set to 150 μm or less, but in all of the examples of the present invention, the amount of warp could be set to 150 μm or less.
[0019]
[Table 2]

[0020]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, a small and thin laminated coil with small deformation can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view of a laminated coil according to an embodiment of the present invention.
FIG. 2 is an exploded view showing the internal structure of the laminated coil according to one embodiment of the present invention.
FIG. 3 is an equivalent circuit of a laminated coil according to one embodiment of the present invention.
FIG. 4 is an internal structure exploded view showing a coil connection state of the laminated coil according to one embodiment of the present invention.
FIG. 5 is a perspective view of a laminated coil according to another embodiment of the present invention.
FIG. 6 is an exploded perspective view of a laminated substrate showing an example of a method for manufacturing a laminated coil according to the present invention.
FIG. 7 is a plan view of a laminated substrate on which a plurality of laminated coils according to the present invention are formed.
FIG. 8 is a sectional view of a brushless motor using a laminated coil according to an embodiment of the present invention. FIG. 9 is an exploded perspective view of a conventional laminated coil.
[Explanation of symbols]
Reference Signs List 1 laminated coil 10 through hole 60 first coil pole 61 second coil pole 62 third coil pole 200, 201a, 201b, 201c, 210 first connection lines 251a to 251h, 252a to 252h, 253a to 253h Coil 300a-300c Second coils 310a-310c Deformation suppressing electrode pattern

Claims (5)

A plurality of coil poles formed of a coil formed of a conductor pattern on a laminate obtained by laminating insulator layers, and input terminal electrodes and output terminal electrodes formed on the outer surface of the laminate and connected to the coil poles are integrated. Wherein the input terminal electrode and the output terminal electrode are formed at corners on one main surface of the laminate that do not substantially overlap with the coil poles in the lamination direction. A laminated coil, wherein a deformation suppressing electrode pattern which does not overlap with the coil pole in the laminating direction but overlaps with the input terminal electrode and the output terminal electrode in the laminating direction is formed on the other main surface. The laminated coil according to claim 1, wherein the deformation suppressing electrode pattern is formed in a shape approximate to the input terminal electrode and the output terminal electrode. The multilayer coil according to claim 1, wherein the input terminal electrode and the output terminal electrode are connected to the deformation suppressing electrode pattern by a through hole or a side electrode formed in a multilayer body. 4. A plurality of coil poles formed of a spiral coil formed by a conductor pattern on a laminate formed by laminating insulator layers; and an input terminal electrode and an output terminal electrode formed on one main surface of the laminate and connected to the coil pole A laminated coil having a thickness of A between the spiral coils, and a first coil between the spiral coil and a main surface on which the input terminal electrode and the output terminal electrode are formed. When the thickness of the insulator layer in the unformed region is B and the thickness of the insulating layer in the second coil non-formed region between the other main surface of the laminated coil and the spiral coil is C, the thickness of the first conductor pattern non-formed region is The ratio of the insulator layer thickness B to the insulator layer thickness A between the spiral coils is 1 ≦ (B / A) ≦ 10, and the insulation between the insulator layer thickness C in the second coil-free area and the spiral coil Body layer thickness A The ratio is 1 ≦ (C / A) ≦ 10 is laminated coil insulator layer thickness C and the insulator layer thickness B is equal to or substantially equal. The input terminal electrode and the output terminal electrode are formed at corners on one main surface of the laminate that do not substantially overlap with the coil pole in the laminating direction, and the coil pole is formed on another main surface of the laminate. The laminated coil according to claim 4, wherein a deformation suppressing electrode pattern that does not overlap with the input terminal electrode and the output terminal electrode in the stack direction is formed.

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