JP2000277343A - Coil device and transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-size coil device at low cost. SOLUTION: A substrate 1 has a first corner portion C1 between a first side 11 and a second side 12, a second corner portion C2 between the second side 12 and a third side 13, a third corner portions C3 between the third side 13 and a fourth side 14 and a fourth corner portion C4 between the fourth side 14 and the first side 11. A first outside coil end 21 provided in a first coil 2 is provided at the first corner portion C1. A first inside coil end 22 is provided being shifted in the direction of the fourth corner portion C4 with the coil center O1 as a reference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil device and a transformer using the coil device.

[0002]

2. Description of the Related Art In recent years, with the spread of small portable devices such as mobile phones and mobile computers, there has been a demand for further reduction in size and thickness of coil devices mounted on these devices. In addition, since these devices are portable, they must be driven by batteries and must be high-performance coil devices with low energy loss. As a matter of course, low cost is also required.

In order to meet these demands, a winding method, a thin film method, a laminating method and the like have been proposed and put to practical use. However, these construction methods have advantages and disadvantages, and a coil device that satisfies all the above requirements has not been proposed.

For example, the winding method is essentially unsuitable for thinning. Further, if the thickness is reduced, a thin wire must be used, the DC resistance increases, and an energy loss occurs. Therefore, it is difficult to realize a high-performance coil device.

[0005] For example, the thin film method is disclosed in
No. 44, etc., which are thin and suitable for realizing a high-performance coil device. However, in the coil device based on the thin film method proposed so far, the area of the coil end pattern connected to the outside is relatively large, and the plane area (floor area) is large.

Although the laminating method is suitable for obtaining a small and inexpensive coil device, it is difficult to obtain a high-performance coil device having excellent characteristics.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a coil device and a transformer which are small, thin and inexpensive.

Another object of the present invention is to provide a coil device that can use the same photomask in a photolithography process for forming coils on both surfaces of a substrate.

[0009]

In order to solve the above-mentioned problems, a coil device according to the present invention includes a substrate and a first coil.

The substrate includes four sides, a first side and a third side oppose each other, a second side and a fourth side oppose each other, and the first side and the fourth side First between the second side
And a second corner between the second side and the third side, and a third corner between the third side and the fourth side. And a fourth corner between the fourth side and the first side.

[0011] The first coil is provided in a spiral shape on one surface of the substrate, and has a first inner coil end portion and a first coil end.
And an outer coil end. The first outer coil end is provided on the first corner side. The first inner coil end is provided so as to be deviated in the direction of the second corner or the fourth corner with respect to the coil center.

As described above, in the first coil,
The first outer coil end is provided at a first corner. According to this structure, the first corner having the largest area is used when the space between the outermost peripheral edge of the first coil having the spiral pattern and the four sides of the substrate is considered. Thus, the first outer coil end can be formed. Therefore, in forming the first outer coil end portion, the plane area of the substrate can be maximized and the overall shape can be reduced in size.

Further, since the first inner coil end portion is provided so as to be deviated in the direction of the second corner portion or the fourth corner portion with respect to the coil center, the first inner coil end portion is provided. Coil bulge by the ends can be absorbed at the second corner or the fourth corner without the first outer coil ends. Therefore, the size of the substrate can be reduced.

The coil device according to the present invention is preferably
A second coil is included. The second coil is formed on the other surface (back surface) of the substrate. The second inner coil end provided in the second coil is provided at a position facing the first inner coil end. A second outer coil end is provided on the third corner side. According to this structure, even when the first coil and the second coil are provided on both surfaces of the substrate, the shape of the substrate can be reduced.

The present invention further discloses a coil device that can use the same photomask in a photolithography step when coils are formed on both surfaces of a substrate.

In this coil device, the first coil is formed in a region surrounded by a virtual square set on one surface of the substrate. A first outer coil end of the first coil has a first through-hole, and the first through-hole is located on a first diagonal of the virtual square. The first inner coil end of the first coil is provided on a second diagonal line of the virtual square deviated from the coil center, and the second through-hole positioned on the second diagonal line of the virtual square. Has a hole.

The second coil has substantially the same pattern as the first coil, shares the coil center with the first coil,
Approximately 90 around the coil center with respect to the first coil
It is arranged at a position rotated by degrees.

The present invention further provides a coil device as described above,
Disclosed is a transformer in combination with a core. Thus, a compact, thin, and high-performance transformer can be obtained.

Other objects, configurations and advantages of the present invention will be described in more detail with reference to the accompanying drawings. The accompanying drawings are merely illustrative.

[0020]

FIG. 1 is a plan view of a coil device according to the present invention. The illustrated coil device includes a substrate 1 and a first coil 2. The substrate 1 includes a first side 11, a second side 12, a third side 13, and a fourth side 14, and the first side 11 and the third side 13 are mutually The second side 12 and the fourth side 14 face each other.
The substrate 1 has a first corner C1 between the first side 11 and the second side 12, and a second corner C2 between the second side 12 and the third side 13. , A third corner C3 between the third side 13 and the fourth side 14, and a fourth corner C4 between the fourth side 14 and the first side 11. Having.

The substrate 1 typically has a square or rectangular planar shape. If it is square or rectangular, after forming many coil elements on one wafer used as the substrate 1, the wafer is divided using a dicing saw or the like, and each coil element is taken out as a coil device. Can be mass-produced.

The illustrated embodiment shows a case where the substrate 1 is formed in a square shape, and a line connecting the ridge of the first corner C1 and the ridge of the third corner C3 is a first diagonal X. The line connecting the corner of the second corner C2 and the corner of the fourth corner C4 is the second diagonal Y. The substrate 1 may be rounded or chamfered at the corners of the corners C1 to C4. In addition, a second corner portion C2 in which an outer coil end and a conductor land, which will be described later, are not disposed and the coil has no bulging portion,
The ridge may be largely cut off.

As the substrate 1, various materials such as a non-magnetic material, a magnetic material and an electric insulating material can be used. More specifically, examples thereof include non-magnetic ceramics, magnetic ceramics such as ferrite, plastics such as glass epoxy resin, and composite compositions. Selection of the type, size, thickness, and the like of the substrate 1 belongs to design matters. As a practical example, a thickness of 0.1 mm and a size of 3.
An example of a 5 mm square can be given.

The first coil 2 is provided in a spiral shape on one surface of the substrate 1, and has a first inner coil end 22 and a first coil end 22.
And the outer coil end 21. The first outer coil end 21 is provided at the first corner C1. In the plane of the first outer coil end portion 21, a first through hole 25 penetrating from one surface side of the substrate 1 to the other surface side is provided on the first diagonal line X. The first inner coil end 22 is
It is provided so as to be deviated in the direction of the fourth corner C4 with respect to the coil center O1. More specifically, on a second diagonal Y connecting the ridge corner of the second corner C2 and the ridge of the fourth corner C4, the ridge is provided so as to be deviated in the direction of the fourth corner C4. Have been. In the illustrated embodiment, since the substrate 1 is square, the coil center O1 coincides with the intersection of the first diagonal X and the second diagonal Y. First inner coil end 2
2 may be displaced in the direction of the second corner C2 differently from the illustration. However, the entire coil pattern has a shape different from that illustrated.

The first inner coil end 22 is guided to the other surface (back surface) of the substrate 1 by a second through hole 23 penetrating the substrate 1, and the third corner C 3 is formed by the conductor 30.
Is led to. A third through hole 26 is provided in the third corner C3. Third through hole 26
Is provided on the first diagonal line X so as to penetrate from the other surface side of the substrate 1 to the one surface side, and is conductively connected to the first conductor land 24 provided on one surface of the substrate 1. The first inner coil end 22 is led out to the first conductor land 24 by the conductor 30 and the third through hole 26.

The thickness, width and number of turns of the first coil 2 belong to design matters. As a practical example, for example, when the size of the substrate 1 is 3.5 mm square, the coil film thickness is 120 μm.
m, a width of 80 μm, and a number of turns of 17.5 turns.

As described above, in the first coil 2, the first outer coil end 21 is provided at the first corner C1. When the substrate 1 is a square or a rectangle, the area becomes the largest when the interval between the outermost peripheral edge of the first coil 2 having the spiral pattern and the four sides of the substrate 1 is considered. The four corners C1 to C4. In this embodiment, the first corner, one of the four corners C1 to C4,
The first outer coil end 21 is formed using the corner C1 of the first outer coil. For this reason, in forming the first outer coil end portion 21, the plane area of the substrate 1 is maximally utilized, and the overall shape can be reduced in size.

Further, since the first inner coil end 22 is offset from the coil center O1 in the direction of the fourth corner C4, the first inner coil end 22 is provided. Can be absorbed by the fourth corner portion C4 without the first outer coil end portion 21. Thus, the size of the substrate 1 can be reduced.

In the embodiment, since the substrate 1 is square,
The first inner coil end 22 is located on a second diagonal Y intersecting with a first diagonal X passing through a ridge of the first corner C1 and a ridge of the third corner C3. Become. This arrangement is effective for further improving the utilization efficiency of the substrate 1. For example, regarding the first coil 2, the fourth corner C4
Is smaller than the radius of curvature of the coil pattern seen on the side of the second corner C2 at the diagonal position, so that the radius of curvature of the first corner is closer to the fourth corner C4. The coil 2 is expanded, the utilization efficiency of the substrate 1 is improved, and the size can be reduced.

FIG. 2 is a view showing another embodiment of the coil device according to the present invention. In the figure, the same components as those shown in FIG. 1 are denoted by the same reference numerals. The feature of this embodiment is that the substrate 1 has a horizontally long (in the figure) rectangular shape, and the first
The overall pattern of the coil 2 is changed.

In the embodiment shown in FIG.
The first outer coil end portion 21 included in the coil 2 is provided at the first corner C1. In the case of the embodiment in which the substrate 1 is rectangular, the area becomes the largest when considering the space between the outermost peripheral edge of the first coil 2 having the spiral pattern and the four sides of the substrate 1. Is the four corners C1
To C4. Therefore, the first outer coil end 21 is formed by using the first corner C1 which is one of the four corners C1 to C4.
To form According to this structure, when forming the first outer coil end portion 21, the plane area of the substrate 1 is maximized, and the overall shape can be reduced in size.

Further, since the first inner coil end portion 22 is provided so as to be deviated in the direction of the fourth corner portion C4 with respect to the coil center O1, the first inner coil end portion 22 is provided. Can be absorbed by the fourth corner portion C4 without the first outer coil end portion 21. Thus, the size of the substrate 1 can be reduced.

In the embodiment, since the substrate 1 is rectangular,
The first inner coil end 22 is located on a second diagonal Y intersecting with a first diagonal X passing through a ridge of the first corner C1 and a ridge of the third corner C3. Become. This arrangement is effective for further improving the utilization efficiency of the substrate 1. For example, regarding the first coil 2, the fourth corner C4
Is smaller than the radius of curvature of the coil pattern seen on the side of the second corner C2 at the diagonal position, so that the radius of curvature of the first corner is closer to the fourth corner C4. The second coil 3 and the second coil 3 are projected, so that the utilization efficiency of the substrate 1 can be improved and the size can be reduced.

In the embodiment shown in FIGS. 1 and 2, the first inner coil end 22 is provided on the second through hole 23, the third through hole 26 and the other surface (back surface) of the substrate 1. And the first conductor land 24 via the conductor 30 provided. The second coil 3 is provided on the other surface side of the substrate 1 instead of the conductor 30, and one coil in which the front and back coils are connected in series can be configured.

That is, in the embodiment shown in FIG. 1, the spiral direction of the coil is the same, and the inner coil end is provided at a position symmetrical to the first inner coil end 22 in the left-right direction.
The use efficiency of the substrate 1 was improved by using a mask having a pattern for the outer coil end for the back coil and the conductor land at the upper and lower symmetric positions of the outer coil end 21 and the first conductor land 24, respectively. A small coil can be obtained.

FIG. 3 is a plan view of a coil device according to the present invention.
4 is a bottom view of the coil device shown in FIG. 3 when it is inverted left and right, FIG. 5 is a sectional view taken along line 5-5 in FIG. 3, and FIG. 6 is a sectional view taken along line 6-6 in FIG. FIG. The illustrated coil device includes a substrate 1, a first coil 2, and a second coil 3.
And The configurations of the substrate 1 and the first coil 2 are as already described with reference to FIGS.

The second coil 3 has the same pattern as the first coil 2, shares a coil center O 1 with the first coil 2, and uses the first coil 2 as a reference, The arrangement is rotated by 90 degrees around the center O1. More specifically, the second coil 3 is provided in a spiral shape on the other surface of the substrate 1 and has a second outer coil end portion 31.
And a second inner coil end 32. The second inner coil end 32 is electrically connected to the first inner coil end 22 by the second through hole 23 penetrating the substrate 1. The second outer coil end 31 is provided at a third corner C3. In the plane of the second outer coil end 31, a third through-hole 26 is provided on the first diagonal line X and penetrates from the other surface of the substrate 1 to one surface.

The thickness, width and number of turns of the second coil 3 belong to design matters. As a practical example, for example, when the size of the substrate 1 is 3.5 mm square, the coil film thickness is 120 μm.
m, a width of 80 μm, and a number of turns of 17.5 turns. Further, in this embodiment, the substrate 1 is formed in a square shape, and the first corner C1 is formed from the center of the first through hole 25.
And the distance from the center of the third through hole 26 to the ridge corner of the third corner C3 have the same size △ d1.

As described above, in the first coil 2, the first outer coil end 21 is provided at the first corner C1. When the substrate 1 is a square or a rectangle, the area becomes the largest when the interval between the outermost peripheral edge of the first coil 2 having the spiral pattern and the four sides of the substrate 1 is considered. The four corners C1 to C4. In this embodiment, the first corner, one of the four corners C1 to C4,
The first outer coil end 21 is formed using the corner C1 of the first outer coil. For this reason, in forming the first outer coil end portion 21, the plane area of the substrate 1 is maximally utilized, and the overall shape can be reduced in size.

Further, since the first inner coil end portion 22 is provided so as to be deviated in the direction of the fourth corner C4 with respect to the coil center O1, the first inner coil end portion 22 is provided. Can be absorbed by the fourth corner portion C4 without the first outer coil end portion 21. Thus, the size of the substrate 1 can be reduced.

In the embodiment, since the substrate 1 is square,
First inner coil end 22 and second inner coil end 3
2 will be located on the second diagonal Y intersecting the first diagonal X passing through the ridge of the first corner C1 and the ridge of the third corner C3. This arrangement is effective for further improving the utilization efficiency of the substrate 1. For example, for the first coil 2 and the second coil 3, the radius of curvature of the coil pattern viewed on the side of the fourth corner C4 is the coil pattern viewed on the side of the second corner C2 at a diagonal position. By making it smaller than the radius of curvature, the first corner C4
The second coil 3 and the second coil 3 are swelled, the utilization efficiency of the substrate 1 is improved, and the size can be reduced.

Further, the second inner coil end 32 is electrically connected to the first inner coil end 22 by the second through hole 23 penetrating the substrate 1. Thereby, a coil device in which the first coil 2 and the second coil 3 are connected in series is obtained.

The first coil 2 and the second coil 3 have the same current direction when viewed from one surface side of the substrate 1. Therefore, when a current flows through the first coil 2 and the second coil 3 connected in series, a magnetic field in the same direction is generated. That is, although the first coil 2 and the second coil 3 are provided on one surface and the other surface of the substrate 1, a high-performance coil device that functions substantially as a single coil can be realized.

Further, the coil device shown in FIGS.
When forming the first coil 2 and the second coil 3 through a photolithography process, the same photomask can be used. Next, this point will be described.

First, in the first coil 2, the first outer coil end 21 has a first through hole 25. The first through hole 25 is formed in the square substrate 1.
Are located on the first diagonal line X. The first inner coil end 22 has a second through hole 23. The second through hole 23 is located on a second diagonal line Y having a square shape.

Next, the second coil 3 is connected to the first coil 2
, The coil center O1 is shared with the first coil 2, and the coil center O1 is rotated by 90 degrees around the coil center O1 with respect to the first coil 2. Therefore, for example, when forming the first coil 2 and the second coil 3 by a photolithography process or the like, the photomask (or wafer) used to form the first coil 2 is rotated by 90 degrees. This makes it possible to form the second coil 3 at a position that completely overlaps the first coil 2. When the first coil 2 and the second coil 3 are formed by applying a photolithography process and a plating technique, a high-performance coil device having a high-precision pattern can be manufactured with high productivity.

In the illustrated embodiment, the substrate 1 has a first conductor land 24 at a third corner C3 on one surface on which the first coil 2 is formed, and the second coil 3 is formed. A second conductor land 34 is provided at the position of the first corner C1 on the surface. The first outer coil end 21 is electrically connected to the second conductor land 34 by the first through hole 25 penetrating the substrate 1. Further, the second outer coil end 31 is connected to the substrate 1.
The first through hole 26 penetrates the first conductive land 24. Therefore, the first outer coil end 21 and the second outer coil end 31 can be connected to an external circuit on both surfaces of the substrate 1. That is, since there is no directionality on both sides of the substrate 1, for example, the assembling work when assembling a transformer or the like becomes easy. Second
Through hole 23, first through hole 25 and third through hole
Is formed on a wafer constituting the substrate 1.
For example, when the first coil 2 and the second coil 3 are formed by plating after forming a small hole of about 0.2 mm, plating can be formed even in the small hole by growing the plating.

Further, in the embodiment shown in FIGS. 3 to 6, a through hole 15 is provided at a substantially central portion of the substrate 1. The through hole 15 is used for inserting a core when, for example, a transformer or the like is configured. For example, when forming an air-core coil device, the through-hole 15 is unnecessary. In the above embodiment, the example in which the first coil 2 and the second coil 3 are provided on both surfaces of the substrate 1 has been described.
For example, a structure including only the first coil 2 may be used. Although illustration is omitted, the substrate 1 may have a plurality of coils on one surface or the other surface.

FIG. 7 is a plan view of another embodiment of the coil device according to the present invention, and FIG. 8 is a bottom view of the coil device shown in FIG. The same components as those shown in FIGS. 3 to 6 are denoted by the same reference numerals. In comparison with the embodiment shown in FIGS. 3 to 6, a feature of the embodiment shown in FIGS. 7 and 8 is that the planar shape of the substrate 1 is rectangular.
The first outer coil end 21 is formed by using the first corner C1 of the four corners C1 to C4 of the rectangular substrate 1. Therefore, in forming the first outer coil end portion 21, the plane area of the substrate 1 is maximized, and the overall shape can be reduced in size.

Further, the first inner coil end portion 22 is provided so as to be deviated in the direction of the fourth corner portion C4 with respect to the coil center O1. Therefore, the first inner coil end 2
2 can be absorbed at the fourth corner C4 without the first outer coil end 21. For this reason,
The shape of the substrate 1 can be reduced in size.

Further, the first coil 2 and the second coil 3
, The radius of curvature of the coil pattern viewed on the side of the fourth corner C4 is made smaller than the radius of curvature of the coil pattern viewed on the side of the second corner C2 located at the diagonal position, thereby forming the fourth corner. On the part C4 side, the first coil 2 and the second coil 3 are made to protrude, so that the utilization efficiency of the substrate 1 can be improved and the size can be reduced.

The second inner coil end 32 is electrically connected to the first inner coil end 22 by the second through hole 23 penetrating the substrate 1. Thereby, a coil device in which the first coil 2 and the second coil 3 are connected in series is obtained.

Further, in the coil device shown in FIGS. 7 and 8, when forming the first coil 2 and the second coil 3, the same photomask can be used in the photolithography step. Next, this point will be described.

First, the first coil 2 is formed in a region surrounded by a virtual square R1 imagined on one surface of the substrate 1. The first outer coil end 21 of the first coil 2 has a first through hole 25. The first through hole 25 is located on the first diagonal line X of the virtual square R1. The first diagonal line X is a line segment connecting the edge of the virtual square R1 generated on the first corner C1 side and the edge of the virtual square R1 generated on the third corner C3 side.

The first inner coil end 22 has a second through hole 23. The second through hole 23 is located on the second diagonal Y of the virtual square R1. The second diagonal Y is a line segment connecting the ridge corner of the virtual square R1 generated on the second corner C2 side and the ridge corner of the virtual square R1 generated on the fourth corner C4 side.

The second coil 3 has the same pattern as the first coil 2, shares the coil center O 1 with the first coil 2, and has the coil center O 1 based on the first coil 2.
Is rotated by 90 degrees. The coil center O1 coincides with the intersection of the first diagonal X and the second diagonal Y.

Therefore, when forming the first coil 2 and the second coil 3 by a photolithography process or the like, the photomask (or wafer) used to form the first coil 2 is rotated by 90 degrees. By doing so, it is possible to form the second coil 3 at a position completely overlapping the first coil 2.

FIG. 9 is an enlarged cross section showing a part of the coil of the coil device shown in FIGS. FIG. 9 shows the first coil 2 formed by applying a photolithography process and a plating technique. Wirings (turns) 201 constituting the first coil 2 are formed with a minimum line interval G1. The wiring 201 has a height H1 larger than the minimum line spacing G1 and a ratio (H1 / 1) of 1 or more.
G1) is maintained. Therefore, while increasing the wiring density,
The cross-sectional area of the wiring 201 can be increased, and the electric resistance of the coil can be reduced. Since the ratio (H1 / G1) and the wiring density are determined by the photolithography process and the plating technique, a high-performance flat coil plate having a high-precision pattern can be manufactured with high productivity. As an example, the line width W1 =
80 μm, height H1 = 120 μm, line interval G = 20 μ
Examples of m can be given. In this case, the ratio (H1 / G
1) becomes 6. Although not shown, the second coil 3 also has a similar ratio (H1 / G1).

When the coil device according to the present invention is manufactured through a photolithography process, the conditions under which the same photomask can be used do not depend on the shape of the substrate 1. The shape of the substrate 1 is determined by forming a number of coil elements on a wafer using the same photomask,
Or it depends on what you want to process. Next, this point will be described with reference to FIG.

FIG. 10 shows a square wafer 100 formed by using photomasks in which conductor patterns shown in FIGS. 3 to 6 are formed in virtual squares arranged in rows and columns at the same interval. A state in which a large number (16 in the figure) of coil elements Q1 to Q16 are formed is shown above. Although not shown in the figure, on the back side of the wafer 100, FIG.
The second coil is formed in the relationship as shown in FIGS. If the square wafer 100 is used, the second on the back side
Can be formed by rotating the photomask (or the wafer 100) used to form the first coil on the front side by 90 degrees.

To take out the square coil device shown in FIGS. 3 to 6 from the wafer 100 in FIG.
Is cut, the cut-out dimension △ A of the horizontal cutting line A1-A2 is made equal to the cut-out dimension △ B of the vertical cutting line B1-B2. In order to take out the rectangular coil device shown in FIGS.
May be set as, for example, △ A> △ B. After the cutting, chamfering, rounding, partial grinding, or the like of the corners can be performed, and substrates 1 having various shapes can be obtained.

Further, a coil device including an arbitrary number of coil elements can be obtained depending on the wafer cutting position. For example, as shown in FIG. 11, a plurality of (four in the figure) coil elements Q1 to Q4 are linearly arranged on a single substrate 1, or a plurality of (as shown in FIG. A coil device in which (in the figure, four) coil elements Q1 to Q4 are arranged in a matrix can be obtained. Although not shown in FIGS. 11 and 10, a second coil is provided on the back side of the substrate 1.

FIG. 13 is a cross-sectional view of a transformer using the coil device shown in FIGS. The illustrated transformer is configured by combining coil devices 41 and 42 and cores 51 and 52. In the illustrated embodiment, the core 5
Reference numeral 1 denotes an I-shaped core, and a core 52 is an E-shaped core having a middle leg 521 and outer legs 522, 523. The center leg 521 of the core 52 is inserted into the through hole 15 of the coil devices 41 and 42. The shapes and structures of the cores 51 and 52 may be arbitrary.

As the coil devices 41 and 42, the coil devices according to the present invention shown in FIGS. 3 to 8 are used. Therefore, it is clear that a small, thin, and inexpensive high-performance transformer can be obtained.

[0065]

As described above, according to the present invention, the following effects can be obtained. (A) It is possible to provide a small, thin and inexpensive coil device and transformer. (B) It is possible to provide a coil device that can use the same photomask in a photolithography process for forming a coil on both surfaces of a substrate.

[Brief description of the drawings]

FIG. 1 is a plan view of a coil device according to the present invention.

FIG. 2 is a plan view showing another embodiment of the coil device according to the present invention.

FIG. 3 is a plan view showing still another embodiment of the coil device according to the present invention.

FIG. 4 is a bottom view of the coil device shown in FIG. 3;

FIG. 5 is a sectional view taken along the line 5-5 in FIG. 3;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 3;

FIG. 7 is a plan view of another embodiment of the coil device according to the present invention.

FIG. 8 is a bottom view of the coil device shown in FIG. 7;

FIG. 9 is an enlarged sectional view showing a part of a coil of the coil device shown in FIGS. 3 to 8;

FIG. 10 is a diagram showing a state in which a large number of coil elements are formed on one square wafer.

FIG. 11 is a plan view of still another embodiment of the coil device according to the present invention.

FIG. 12 is a plan view of still another embodiment of the coil device according to the present invention.

FIG. 13 is a sectional view of a transformer using the coil device shown in FIGS. 3 to 8;

[Explanation of symbols]

 Reference Signs List 1 substrate 2 first coil 3 second coil 21 first outer coil end 22 first inner coil end 31 second outer coil end 32 second inner coil end

Claims (9)

[Claims] 1. A coil device including a substrate and a first coil, wherein the substrate includes four sides, a first side and a third side face each other, and a second side. And the fourth side face each other,
A first corner between the first side and the second side; a second corner between the second side and the third side; A third corner between the third side and the fourth side, and a fourth corner between the fourth side and the first side; The first coil is provided in a spiral shape on one surface of the substrate, and includes a first inner coil end and a first outer coil end. The first outer coil end includes the first outer coil end. Wherein the first inner coil end is offset from the coil center in the direction of the second corner or the fourth corner. apparatus. 2. The coil device according to claim 1, further comprising a second coil, wherein the second coil has a second inner coil end, a second outer coil end, and a second inner coil end. Wherein the second inner coil end is provided at a position facing the first inner coil end, and the second outer coil is provided on the other surface of the substrate in a spiral shape. An end portion is a coil device provided on the third corner side. 3. The coil device according to claim 2, wherein the substrate has a square shape, the first outer coil end has a first through-hole, and the first through-hole has a first through-hole. The hole is located on a first diagonal line of the substrate, and the first inner coil end portion is provided on a second diagonal line of the substrate so as to be deviated from a coil center.
A second through-hole located on a diagonal line of the second coil, the second coil has substantially the same pattern as the first coil, and shares the coil center with the first coil. A coil device disposed at a position rotated by about 90 degrees around the coil center with respect to the first coil. 4. A coil device including a substrate, at least one first coil, and at least one second coil, wherein the first coil has a spiral shape and a first inner side. A first outer coil end portion including a coil end portion and a first outer coil end portion, the first outer coil end portion being formed in a region surrounded by a virtual square set on the one surface of the substrate; Wherein the first through-hole is the first of the virtual square.
And the first inner coil end portion is provided on a second diagonal line of the virtual square displaced from the coil center, and is located on a second diagonal line of the virtual square. The second coil has substantially the same pattern as the first coil, the coil center is shared with the first coil, and the first coil is A coil device arranged at a position rotated by about 90 degrees around the coil center as a reference. 5. The coil device according to claim 3, further comprising a first conductor land and a second conductor land, wherein the first conductor land and the second conductor The lands have the same pattern, and the first conductor lands are provided on the one surface of the substrate so as to overlap with the end of the second outer coil. The second conductive land is provided on the other surface of the substrate so as to overlap with the first outer coil end, and the first conductor land is provided on the other surface of the substrate so as to overlap the first outer coil end. A coil device that is electrically connected to the first outer coil end portion through the through hole. 6. The coil device according to claim 1, wherein the first coil and the second coil are offset from the first and second inner coil ends. A coil device in which the radius of curvature of the coil pattern seen in the direction is smaller than the radius of curvature of the coil pattern seen in other parts. 7. The coil device according to claim 1, wherein the first coil or the second coil has a ratio between a minimum line interval G1 and a height H1. A coil device wherein H1 / G1) is 1 or more. 8. The coil device according to claim 4, wherein the first coil and the second coil are respectively
A plurality of coil devices. 9. A transformer including a coil device and a core, wherein the coil device is as described in claim 1 and is combined with the core.