Coil device and actuator

Abstract

To provide a coil device capable of suppressing torque fluctuations due to rotational phase. [Solution] The coil device comprises a first printed circuit board and a second printed circuit board. The first printed circuit board has a first base film having a first main surface and first wiring arranged on the first main surface. The first wiring is formed by winding the first wiring in a spiral shape in a plan view and has a plurality of first coil portions arranged along the circumferential direction. The second printed circuit board has a second base film having a second main surface and a third main surface, and second wiring arranged on the second main surface. The third main surface faces the first main surface. The second wiring is formed by winding the second wiring in a spiral shape in a plan view and has a plurality of second coil portions arranged along the circumferential direction.

Description

Technical Field

[0001] The present disclosure relates to a coil device and an actuator.

Background Art

[0002] JP-A-2024-71959 (Patent Document 1) describes an axial-gap motor. The axial-gap motor described in Patent Document 1 has a coil device and a magnet. The coil device has a substrate and a plurality of winding coils arranged on the substrate. The plurality of winding coils are arranged in an annular shape along the circumferential direction in a plan view. Due to the interaction between the magnetic field generated by the magnet and the current flowing through the winding coils, a torque for rotating the coil device in the circumferential direction is generated in the plurality of winding coils.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the coil device of the axial-gap motor described in Patent Document 1, the above torque varies greatly depending on the rotational phase. The present disclosure has been made in view of such prior art. More specifically, the present disclosure provides a coil device capable of suppressing fluctuations in torque due to the rotational phase.

Means for Solving the Problems

[0005] The coil device of this disclosure comprises a first printed circuit board and a second printed circuit board. The first printed circuit board has a first base film having a first main surface and first wiring arranged on the first main surface. The first wiring has a plurality of first coil portions arranged in a spiral shape in a plan view and aligned along the circumferential direction. The second printed circuit board has a second base film having a second main surface and a third main surface, and second wiring arranged on the second main surface. The third main surface faces the first main surface. The second wiring has a plurality of second coil portions arranged in a spiral shape in a plan view and aligned along the circumferential direction. In a plan view, the second printed circuit board is offset in the circumferential direction from the first printed circuit board such that one of the plurality of second coil portions overlaps with two adjacent first coil portions among the plurality of first coil portions. [Effects of the Invention]

[0006] The coil device of this disclosure can suppress torque fluctuations due to rotational phase. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a first plan view of the coil device 100. [Figure 2] Figure 2 is a second plan view of the coil device 100. [Figure 3] Figure 3 is a third plan view of the coil device 100. [Figure 4] Figure 4 is a fourth plan view of the coil device 100. [Figure 5] Figure 5 is a cross-sectional view of VV in Figure 3. [Figure 6] Figure 6 is a cross-sectional view of the section VI-VI in Figure 3. [Figure 7] Figure 7 is a first cross-sectional view illustrating the operation of the coil device 100. [Figure 8] Figure 8 is a second cross-sectional view illustrating the operation of the coil device 100. [Figure 9]Figure 9 is a graph showing the torque applied to multiple coil sections 33 and multiple coil sections 43 in the coil device according to the comparative example. [Figure 10] Figure 10 is a graph showing the torque applied to multiple coil sections 33 and multiple coil sections 43 in a coil device relating to a comparative example when power supply control is performed. [Figure 11] Figure 11 is a graph showing the torque applied to multiple coil sections 33 and multiple coil sections 43 in the coil device 100. [Figure 12] Figure 12 is a graph showing the torque applied to multiple coil sections 33 and multiple coil sections 43 in the coil device 100 when power supply control is performed. [Figure 13] Figure 13 is a graph showing the combined torque applied to the coil device 100 when power supply control is performed. [Modes for carrying out the invention]

[0008] [Description of Embodiments in this Disclosure] First, embodiments of this disclosure will be listed and described.

[0009] (1) The coil device according to the embodiment comprises a first printed circuit board and a second printed circuit board. The first printed circuit board has a first base film having a first main surface and first wiring arranged on the first main surface. The first wiring has a plurality of first coil portions arranged in a spiral shape in a plan view and aligned along the circumferential direction. The second printed circuit board has a second base film having a second main surface and a third main surface and second wiring arranged on the second main surface. The third main surface faces the first main surface. The second wiring has a plurality of second coil portions arranged in a spiral shape in a plan view and aligned along the circumferential direction. In a plan view, the second printed circuit board is offset in the circumferential direction from the first printed circuit board such that one of the plurality of second coil portions overlaps with two adjacent first coil portions among the plurality of first coil portions. According to the coil device of (1) above, fluctuations in torque due to rotational phase can be suppressed.

[0010] (2) In the coil device described in (1) above, each of the plurality of first coil sections may have a first section and a second section that extend along the circumferential direction in a plan view and are spaced apart from each other along the radial direction perpendicular to the circumferential direction. Each of the plurality of second coil sections may have a third section and a fourth section that extend along the radial direction in a plan view and are spaced apart from each other along the circumferential direction. The second printed circuit board may be offset in the circumferential direction with respect to the first printed circuit board such that, in a plan view, the third section of one second coil section overlaps with the first and second sections of one of two adjacent first coil sections, and the fourth section of one second coil section overlaps with the first and second sections of the other of two adjacent first coil sections. The coil device described in (2) above can further suppress torque fluctuations due to rotational phase.

[0011] (3) In the coil device according to (1) or (2) above, the first base film may have a fourth main surface. The first printed circuit board may further have third wiring arranged on the fourth main surface. The third wiring may have a plurality of third coil sections arranged in a spiral shape in a plan view and aligned along the circumferential direction. Each of the plurality of third coil sections may overlap with each of the plurality of first coil sections in a plan view. The second printed circuit board may further have fourth wiring arranged on the third main surface. The fourth wiring may have a plurality of fourth coil sections arranged in a spiral shape in a plan view and aligned along the circumferential direction. Each of the plurality of fourth coil sections may overlap with each of the plurality of second coil sections in a plan view.

[0012] (4) The coil device according to another embodiment includes a printed wiring board. The printed wiring board has a base film having a first main surface and a second main surface, a first wiring disposed on the first main surface, and a second wiring disposed on the second main surface. The first wiring is formed by winding the first wiring in a spiral shape in a plan view and has a plurality of first coil portions arranged along the circumferential direction. The second wiring is formed by winding the second wiring in a spiral shape in a plan view and has a plurality of second coil portions arranged along the circumferential direction. In a plan view, one of the plurality of second coil portions is displaced in the circumferential direction so as to overlap two adjacent first coil portions among the plurality of first coil portions. According to the coil device of (4) above, fluctuations in torque due to the rotational phase can be suppressed.

[0013] (5) The actuator according to the embodiment includes the coil device of (1) to (4) above and a magnet that generates a magnetic field along the normal directions of the first main surface and the second main surface. According to the actuator of (3) above, fluctuations in torque due to the rotational phase in the coil device can be further suppressed.

[0014] [Details of Embodiments of the Present Disclosure] Next, the details of the embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and overlapping descriptions will not be repeated. The coil device according to the embodiment is referred to as coil device 100.

[0015] (Configuration of Coil Device 100) The configuration of coil device 100 will be described below.

[0016] Figure 1 is a first plan view of the coil device 100. Figure 2 is a second plan view of the coil device 100. Figure 3 is a third plan view of the coil device 100. Figure 4 is a fourth plan view of the coil device 100. In Figure 1, the printed circuit board 20 is not shown. In Figure 4, the printed circuit board 10 is not shown. Figures 2 and 4 show plan views of the coil device 100 viewed from the opposite direction to Figures 1 and 3. As shown in Figures 1 to 4, the coil device 100 includes a printed circuit board 10 and a printed circuit board 20.

[0017] The printed circuit board 10 has a base film 30, wiring 31, and wiring 32. The base film 30 has a main surface 30a and a main surface 30b. The main surface 30b is the opposite surface of the main surface 30a. The main surfaces 30a and 30b are the end faces in the thickness direction of the base film 30. The base film 30 is made of a flexible, electrically insulating material. For example, the base film 30 is made of polyimide.

[0018] The wiring 31 is arranged on the main surface 30a. The wiring 31 has a plurality of coil sections 33. The plurality of coil sections 33 are arranged in a ring shape in a plan view. The direction in which the plurality of coil sections 33 are arranged is sometimes called the circumferential direction DR1. The direction perpendicular to the circumferential direction DR1 is sometimes called the radial direction DR2. In the illustrated example, the wiring 31 has six coil sections 33. These six coil sections 33 are called coil section 33A, coil section 33B, coil section 33C, coil section 33D, coil section 33E, and coil section 33F. When viewed from the main surface 30a side, coil sections 33A, 33B, 33C, 33D, 33E, and 33F are arranged in this order clockwise. The coil sections 33 are formed by winding the wiring 31 in a spiral shape in a plan view. Furthermore, the winding direction of the wiring 31 in one of two adjacent coil sections 33 is opposite to the winding direction of the wiring 31 in the other of the two adjacent coil sections 33.

[0019] The coil portion 33 has a first portion 33a and a second portion 33b, and a third portion 33c and a fourth portion 33d. The first portion 33a and the second portion 33b extend along the circumferential direction DR1 in a plan view and are separated from each other along the radial direction DR2 in a plan view. The third portion 33c and the fourth portion 33d extend along the radial direction DR2 in a plan view and are separated from each other along the circumferential direction DR1 in a plan view.

[0020] The wiring 32 is arranged on the main surface 30b. The wiring 32 has a plurality of coil sections 34. In a plan view, the plurality of coil sections 34 are arranged in an annular shape along the circumferential direction. In the illustrated example, the wiring 32 has six coil sections 34. These six coil sections 34 are designated as coil section 34A, coil section 34B, coil section 34C, coil section 34D, coil section 34E, and coil section 34F. When viewed from the main surface 30b side, coil sections 34A, 34B, 34C, 34D, 34E, and 34F are arranged in this order in a counterclockwise direction.

[0021] The coil portion 34 is formed by winding the wiring 32 in a spiral shape in a plan view. The winding direction of the wiring 32 in one of two adjacent coil portions 34 is opposite to the winding direction of the wiring 32 in the other of the two adjacent coil portions 34. The coil portion 34 has a first portion 34a and a second portion 34b that extend along the circumferential direction DR1 in a plan view and are separated from each other along the radial direction DR2 in a plan view, and a third portion 34c and a fourth portion 34d that extend along the radial direction DR2 in a plan view and are separated from each other along the circumferential direction DR1 in a plan view.

[0022] Each of the multiple coil sections 34 overlaps with each of the multiple coil sections 33 in a plan view. More specifically, coil sections 34A, 34B, 34C, 34D, 34E, and 34F overlap with coil sections 33A, 33B, 33C, 33D, 33E, and 33F, respectively, in a plan view. One of the multiple coil sections 34 overlaps with only one of the multiple coil sections 33 in a plan view, and does not overlap with any other coil sections 33 in a plan view. In a plan view, the first section 34a and the second section 34b overlap with the first section 33a and the second section 33b, respectively, and the third section 34c and the fourth section 34d overlap with the third section 33c and the fourth section 33d, respectively.

[0023] The wiring 31 further has a plurality of lands 35. Each of the plurality of lands 35 is connected to the innermost circumference of each of the plurality of coil sections 33. The wiring 32 further has a plurality of lands 36. Each of the plurality of lands 36 is connected to the innermost circumference of each of the plurality of coil sections 34. Each of the plurality of lands 36 overlaps with each of the plurality of lands 35 in a plan view and is electrically connected to each of the plurality of lands 35.

[0024] The wiring 31 further has a plurality of connection points 37. Each of the plurality of connection points 37 is connected to the outermost part of each of the plurality of coil sections 33. The wiring 32 further has a plurality of connection points 38. Each of the plurality of connection points 38 is connected to the outermost part of the coil section 34.

[0025] One connector 37 is connected to coil section 33A and is electrically connected to a power terminal (not shown). Another connector 38 is connected to coil section 34F and is electrically connected to a power terminal (not shown). Although not shown, another connector 38 is electrically connected to coil section 34A and is electrically connected to another connector 37 which is connected to coil section 33B. Similarly, coil section 34B and coil section 33C, coil section 34C and coil section 33D, coil section 34D and coil section 33E, and coil section 34D and coil section 33F are electrically connected by connectors 37 and 38.

[0026] The printed circuit board 20 has a base film 40, wiring 41, and wiring 42. The base film 40 has a main surface 40a and a main surface 40b. The main surface 40b is the opposite surface of the main surface 40a. The main surfaces 40a and 40b are the end faces in the thickness direction of the base film 40. The base film 40 is made of a flexible, electrically insulating material. For example, the base film 40 is made of polyimide.

[0027] The wiring 41 is arranged on the main surface 40a. The wiring 41 has a plurality of coil sections 43. The plurality of coil sections 43 are arranged in a ring shape in a plan view. In the illustrated example, the wiring 41 has six coil sections 43. These six coil sections 43 are denoted as coil section 43A, coil section 43B, coil section 43C, coil section 43D, coil section 43E, and coil section 43F. When viewed from the main surface 40a side, coil sections 43A, 43B, 43C, 43D, 43E, and 43F are arranged in this order clockwise. The coil sections 43 are formed by winding the wiring 41 in a spiral shape in a plan view. The winding direction of the wiring 41 in one of two adjacent coil sections 43 is opposite to the winding direction of the wiring 41 in the other of the two adjacent coil sections 43.

[0028] The coil portion 43 has a first portion 43a and a second portion 43b, and a third portion 43c and a fourth portion 43d. The first portion 43a and the second portion 43b extend along the circumferential direction DR1 in a plan view and are separated from each other along the radial direction DR2 in a plan view. The third portion 43c and the fourth portion 43d extend along the radial direction DR2 in a plan view and are separated from each other along the circumferential direction DR1 in a plan view.

[0029] The wiring 42 is arranged on the main surface 40b. The wiring 42 has a plurality of coil sections 44. In a plan view, the plurality of coil sections 44 are arranged in an annular shape along the circumferential direction. In the illustrated example, the wiring 42 has six coil sections 44. These six coil sections 44 are denoted as coil section 44A, coil section 44B, coil section 44C, coil section 44D, coil section 44E, and coil section 44F. When viewed from the main surface 40b side, coil sections 44A, 44B, 44C, 44D, 44E, and 44F are arranged in this order in a counterclockwise direction.

[0030] The coil portion 44 is formed by winding the wiring 42 in a spiral shape in a plan view. The winding direction of the wiring 42 in one of two adjacent coil portions 44 is opposite to the winding direction of the wiring 42 in the other of the two adjacent coil portions 44. The coil portion 44 has a first portion 44a and a second portion 44b that extend along the circumferential direction DR1 in a plan view and are separated from each other along the radial direction DR2 in a plan view, and a third portion 44c and a fourth portion 44d that extend along the radial direction DR2 in a plan view and are separated from each other along the circumferential direction DR1 in a plan view.

[0031] Each of the multiple coil sections 44 overlaps with each of the multiple coil sections 43 in a plan view. More specifically, coil sections 44A, 44B, 44C, 44D, 44E, and 44F overlap with coil sections 43A, 43B, 43C, 43D, 43E, and 43F, respectively, in a plan view. One of the multiple coil sections 44 overlaps with only one of the multiple coil sections 43 in a plan view, and does not overlap with any other coil sections 43 in a plan view. In a plan view, the first section 44a and the second section 44b overlap with the first section 43a and the second section 43b, respectively, and the third section 44c and the fourth section 44d overlap with the third section 43c and the fourth section 43d, respectively.

[0032] The wiring 41 further has a plurality of lands 45. Each of the plurality of lands 45 is connected to the innermost circumference of each of the plurality of coil sections 43. The wiring 42 further has a plurality of lands 46. Each of the plurality of lands 46 is connected to the innermost circumference of each of the plurality of coil sections 44. Each of the plurality of lands 46 overlaps with each of the plurality of lands 45 in a plan view and is electrically connected to each of the plurality of lands 45.

[0033] The wiring 41 further has a plurality of connection points 47. Each of the plurality of connection points 47 is connected to the outermost circumference of each of the plurality of coil sections 43. The wiring 42 further has a plurality of connection points 48. Each of the plurality of connection points 48 is connected to the outermost circumference of the coil section 44.

[0034] One connector 47 is connected to coil section 43A and is electrically connected to a power terminal (not shown). Another connector 48 is connected to coil section 44F and is electrically connected to a power terminal (not shown). Although not shown, another connector 48 is electrically connected to coil section 44A and is electrically connected to another connector 47 which is connected to coil section 43B. Similarly, coil section 44B and coil section 43C, coil section 44C and coil section 43D, coil section 44D and coil section 43E, and coil section 44D and coil section 43F are electrically connected by connectors 47 and 48.

[0035] Wirings 31, 32, 41, and 42 are formed of a conductive material. Wirings 31, 32, 41, and 42 are formed of, for example, copper or a copper alloy. Wirings 31, 32, 41, and 42 may be formed by a semi-additive method or a subtractive method.

[0036] Figure 5 is a cross-sectional view at VV in Figure 3. Figure 6 is a cross-sectional view at VI-VI in Figure 3. As shown in Figures 5 and 6, the printed circuit board 20 is superimposed on the printed circuit board 10 such that its main surface 40b faces its main surface 30a. The printed circuit board 20 is attached to the printed circuit board 10 by an adhesive layer 50 placed between the main surface 30a and the main surface 40b.

[0037] As shown in Figure 3, in a plan view, the rows of coil portions 34 aligned along the circumferential direction DR1 overlap with the rows of coil portions 33 aligned along the circumferential direction DR1. The printed circuit board 20 is offset relative to the printed circuit board 10 along the circumferential direction DR1 such that in a plan view, one coil portion 34 overlaps with both adjacent coil portions 33. For example, the third portion 43c of one coil portion 34 overlaps with the first portion 33a and the second portion 33b of one of the two adjacent coil portions 33 in a plan view, and the fourth portion 43d of the same coil portion 34 overlaps with the first portion 33a and the second portion 33b of the other of the two adjacent coil portions 33 in a plan view.

[0038] More specifically, for example, in a plan view, the third portion 43c of coil portion 43A overlaps with the first portion 33a and the second portion 33b of coil portion 33A, and the fourth portion 43d of coil portion 43A overlaps with the first portion 33a and the second portion 33b of coil portion 33B. This is also true for the relationship between coil portion 43B and coil portions 34B and 34C, the relationship between coil portion 43C and coil portions 34C and 34D, the relationship between coil portion 43D and coil portions 34D and 34E, the relationship between coil portion 43E and coil portions 34E and 34F, and the relationship between coil portion 43F and coil portions 34F and 34A.

[0039] Figure 7 is a first cross-sectional view illustrating the operation of the coil device 100. Figure 8 is a second cross-sectional view illustrating the operation of the coil device 100. As shown in Figures 7 and 8, the actuator using the coil device 100 has a magnet 60. The magnet 60 generates a magnetic field (indicated by a dotted arrow in the figure) along the direction normal to the main surface 40a (main surface 40b, main surface 30a, main surface 30b). In the example shown in Figures 7 and 8, the magnetic field is directed from top to bottom in the figure.

[0040] When the coil device 100 operates, current flows through the wiring 31 and 32, that is, through the multiple coil sections 33 and 34. More specifically, in the examples shown in Figures 7 and 8, current flows through the third section 33c, fourth section 33d, third section 34c, fourth section 34d, third section 43c, fourth section 43d, third section 44c, and fourth section 44d, in the diagram, along the direction perpendicular to the paper, from the back of the paper to the front of the paper.

[0041] As a result of the interaction between the magnetic field and the current described above, thrust (shown by solid arrows in the figure) is generated in the third part 33c, fourth part 33d, third part 34c, fourth part 34d, third part 43c, fourth part 43d, third part 44c, and fourth part 44d along the circumferential direction DR1. Since this thrust is along the circumferential direction DR1, the torque based on this thrust causes the coil device 100 to rotate along the circumferential direction DR1 and function as an actuator.

[0042] (Effect of coil device 100) The effects of the coil device 100 will be explained below in comparison with the coil device of the comparative example.

[0043] In the comparative example coil device, each of the multiple coil sections 34 overlaps with each of the multiple coil sections 33 in a plan view. That is, in the comparative example coil device, the printed circuit board 20 is superimposed on the printed circuit board 10 without displacement along the circumferential direction DR1 such that in a plan view, each coil section 34 overlaps with only one coil section 33. In other respects, the configuration of the comparative example coil device is the same as the configuration of the coil device 100.

[0044] Figure 9 is a graph showing the torque applied to the multiple coil sections 33 and multiple coil sections 43 in the coil device of the comparative example. Figure 10 is a graph showing the torque applied to the multiple coil sections 33 and multiple coil sections 43 in the coil device of the comparative example when power supply control is performed. As shown in Figure 9, in the coil device of the comparative example, the printed circuit board 20 is not shifted relative to the printed circuit board 10 along the circumferential direction DR1, so the phase of the torque applied to the multiple coil sections 33 is not shifted from the phase of the torque applied to the multiple coil sections 43.

[0045] Furthermore, the torque applied to the multiple coil sections 33 and the torque applied to the multiple coil sections 43 change depending on the rotational phase of the coil device according to the comparative example. This variation in torque due to the rotational phase occurs because a strong thrust is generated in the part where current flows along the radial direction DR2, but no strong thrust is generated in the part where current flows along the circumferential direction DR1. As a result, as shown in Figure 10, even if the power supply is controlled so that the torque applied to the multiple coil sections 33 and the torque applied to the multiple coil sections 43 is always positive, the torque applied to the multiple coil sections 33 and the torque applied to the multiple coil sections 43 fluctuates greatly depending on the rotational phase.

[0046] Figure 11 is a graph showing the torque applied to the multiple coil sections 33 and 43 in the coil device 100. Figure 12 is a graph showing the torque applied to the multiple coil sections 33 and 43 in the coil device 100 when power supply control is performed. Figure 13 is a graph showing the combined torque applied to the coil device 100 when power supply control is performed. Figures 11 to 13 show an example where the phase of the torque applied to the multiple coil sections 43 is shifted by λ / 4 relative to the phase of the torque applied to the multiple coil sections 33.

[0047] As described above, in the coil device 100, the printed circuit board 20 is offset from the printed circuit board 10 along the circumferential direction DR1 such that, in a plan view, one coil section 43 overlaps with both adjacent coil sections 33. Therefore, as shown in Figure 11, in the coil device 100, the phase of the torque applied to the multiple coil sections 43 is offset from the phase of the torque applied to the multiple coil sections 33. Consequently, when power supply control is performed so that the torque applied to the multiple coil sections 33 and the torque applied to the multiple coil sections 43 are always positive, one peak of the phase of the torque applied to the multiple coil sections 34 is positioned between two adjacent peaks of the phase of the torque applied to the multiple coil sections 33, and the fluctuation of the combined torque applied to the coil device 100 for each rotational phase becomes smaller.

[0048] To put this from another perspective, in the coil device 100, the coil section 43 (coil section 44) to which strong thrust is applied overlaps with the coil section 33 (coil section 34) to which strong thrust is not applied, while the coil section 33 (coil section 34) to which strong thrust is applied overlaps with the coil section 43 (coil section 44) to which strong thrust is not applied. Therefore, fluctuations in the combined torque applied to the coil device 100 due to rotational phase are suppressed. In this way, the coil device 100 makes it possible to suppress fluctuations in torque and thrust due to rotational phase.

[0049] (modified version) In the above description, an example was given in which the coil device 100 has two printed circuit boards (printed circuit board 10 and printed circuit board 20), but the coil device 100 may have only one printed circuit board. In this case, for example, the coil device 100 does not have printed circuit board 20, and printed circuit board 10 has wiring 41 on its main surface 30b instead of wiring 32. In other words, on a single printed circuit board, each of the multiple coil portions of the wiring arranged on one main surface of the base film 30 may be offset in the circumferential direction DR1 so as to overlap with two adjacent coil portions of the wiring arranged on the other main surface of the base film 30.

[0050] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the embodiments described above, and all modifications within the meaning and scope of the claims are intended to be included. [Explanation of symbols]

[0051] 10,20 Printed circuit board 30 base film 30a,30b main surface 31,32 Wiring 33, 33A, 33B, 33C, 33D, 33E, 33F Coil section 33a Part 1 33b Part 2 33c Part 3 33d 4th part 34, 34A, 34B, 34C, 34D, 34E, 34F Coil section 34a Part 1 34b Part 2 34c Part 3 34d 4th part 35,36 Rand 37,38 Connection part 40 base film 40a,40b main surface 41,42 Wiring 43, 43A, 43B, 43C, 43D, 43E, 43F Coil section 43a Part 1 43b Part 2 43c Part 3 43d 4th part 44, 44A, 44B, 44C, 44D, 44E, 44F Coil section 44a Part 1 44b Part 2 44c Part 3 44d Part 4 45.46 rand 47, 48 Connection part 50 Adhesive layer 60 Magnets 100 Coil Device DR1 Weekly Direction DR2 radial direction

Claims

1. First printed circuit board, It comprises a second printed circuit board, The first printed circuit board has a first base film having a first main surface and first wiring arranged on the first main surface. The first wiring is formed by winding the first wiring in a spiral shape in a plan view and has a plurality of first coil portions arranged along the circumferential direction. The second printed circuit board comprises a second base film having a second main surface and a third main surface, and a second wiring arranged on the second main surface. The third main surface is opposite the first main surface, The second wiring is formed by winding the second wiring in a spiral shape in a plan view and has a plurality of second coil portions arranged along the circumferential direction. The coil device wherein the second printed circuit board is offset in the circumferential direction relative to the first printed circuit board such that, in a plan view, one of the plurality of second coil portions overlaps with two adjacent first coil portions among the plurality of first coil portions.

2. Each of the plurality of first coil portions extends along the circumferential direction in a plan view and has a first portion and a second portion that are spaced apart from each other along the radial direction perpendicular to the circumferential direction. Each of the plurality of second coil portions has a third portion and a fourth portion that extend along the radial direction in a plan view and are spaced apart from each other along the circumferential direction. The coil device according to claim 1, wherein the second printed circuit board is offset in the circumferential direction with respect to the first printed circuit board such that, in a plan view, the third portion of one second coil portion overlaps with the first and second portions of one of the two adjacent first coil portions, and in a plan view, the fourth portion of one second coil portion overlaps with the first and second portions of the other of the two adjacent first coil portions.

3. The first base film has a fourth main surface, The first printed circuit board further has a third wiring arranged on the fourth main surface, The third wiring is formed by winding the third wiring in a spiral shape in a plan view and has a plurality of third coil portions arranged along the circumferential direction. Each of the plurality of third coil sections overlaps with each of the plurality of first coil sections in a plan view. The second printed circuit board further has a fourth wiring arranged on the third main surface, The fourth wiring is formed by winding the fourth wiring in a spiral shape in a plan view and has a plurality of fourth coil portions arranged along the circumferential direction. The coil device according to claim 1, wherein each of the plurality of fourth coil sections overlaps with each of the plurality of second coil sections in a plan view.

4. Equipped with a printed circuit board, The printed circuit board comprises a base film having a first main surface and a second main surface, a first wiring arrangement on the first main surface, and a second wiring arrangement on the second main surface. The first wiring is formed by winding the first wiring in a spiral shape in a plan view and has a plurality of first coil portions arranged along the circumferential direction. The second wiring is formed by winding the second wiring in a spiral shape in a plan view and has a plurality of second coil portions arranged along the circumferential direction. A coil device in which, in a plan view, one of the plurality of second coil portions is offset in the circumferential direction so as to overlap with two adjacent first coil portions among the plurality of first coil portions.

5. The coil device according to any one of claims 1 to 4, An actuator comprising a magnet that generates a magnetic field along the normal direction of the first main surface and the second main surface.

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