Coil device

Abstract

The coil device includes at least one printed wiring board. Each of the at least one printed wiring board has: a first base film having a first main surface and a second main surface, the second main surface being a surface facing the first main surface; and a first wiring disposed on the first main surface. The first wiring has a plurality of first coil sections arranged in a first direction in plan view. Each of the plurality of first coil parts is configured from a first wiring wound in a spiral shape in plan view, and has a first linear part, a second linear part, a first connecting part, and a second connecting part. In plan view, the first wiring located in the first linear portion and the first wiring located in the second linear portion extend in a second direction orthogonal to the first direction.

Description

Technical Field

[0001] The present disclosure relates to a coil device. This application claims priority based on Japanese Patent Application No. 2022-189240 filed on November 28, 2022. All the descriptions recorded in this Japanese patent application are incorporated herein by reference. Background Art

[0002] For example, a coil device described in Japanese Unexamined Patent Application Publication No. 2020-72551 (Patent Document 1) is described. The coil device described in Patent Document 1 has a flexible substrate and wirings. The flexible substrate has a main surface. The wirings are disposed on the main surface. The wirings have a plurality of coils arranged in a first direction in a plan view. Each of the plurality of coils is configured by winding in a spiral shape through the wirings in a plan view, and has a first straight portion, a second straight portion, a third straight portion, a fourth straight portion, a first connection portion, and a second connection portion.

[0003] One end of the first straight portion and one end of the third straight portion are connected by the first connection portion. The other end of the first straight portion and the other end of the third straight portion are respectively connected to one end of the second straight portion and one end of the fourth straight portion. The other end of the second straight portion and the other end of the fourth straight portion are connected by the second connection portion. The wirings located in the first straight portion, the wirings located in the second straight portion, the wirings located in the third straight portion, and the wirings located in the fourth straight portion extend linearly in a manner inclined with respect to a second direction orthogonal to the first direction in a plan view. The extending directions of the wirings located in the first straight portion and the extending directions of the wirings located in the fourth straight portion are parallel to each other. The extending directions of the wirings located in the second straight portion and the extending directions of the wirings located in the third straight portion are parallel to each other, and are inclined with respect to the second direction to the opposite side of the wirings located in the first straight portion and the wirings located in the fourth straight portion. The wirings located in the first connection portion and the wirings located in the second connection portion extend in a semicircular shape in a plan view.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-72551 Summary of the Invention

[0007] The coil device of the present disclosure includes at least one printed wiring board. Each of the at least one printed wiring board has: a first base film having a first main surface and a second main surface, the second main surface being the surface opposite to the first main surface; and a first wiring disposed on the first main surface. The first wiring has a plurality of first coil portions arranged in a first direction in a plan view. Each of the plurality of first coil portions is formed by a first wiring wound in a spiral shape in a plan view and has a first straight portion, a second straight portion, a first connection portion, and a second connection portion. In a plan view, the first wiring located in the first straight portion and the first wiring located in the second straight portion extend in a second direction orthogonal to the first direction. The first straight portion has a first end portion and a second end portion, the first end portion and the second end portion being the two end portions in the second direction. The second straight portion has a third end portion and a fourth end portion, the third end portion and the fourth end portion being the two end portions in the second direction. The first connection portion connects the first end portion and the third end portion. The second connection portion connects the second end portion and the fourth end portion. The sum of the widths of the first connection portion and the second connection portion in the second direction is smaller than the sum of the widths of the first straight portion and the second straight portion in the first direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a first plan view of the coil device 100.

[0009] Figure 2 is a second plan view of the coil device 100.

[0010] Figure 3 is Figure 1 a cross-sectional view taken along line III-III in

[0011] Figure 4 is a first plan view of the coil device 100 according to Modification 1.

[0012] Figure 5 is a second plan view of the coil device 100 according to Modification 1.

[0013] Figure 6 is a manufacturing process diagram of the coil device 100.

[0014] Figure 7 is a cross-sectional view illustrating the preparation process S1.

[0015] Figure 8 is a cross-sectional view illustrating the conductive layer formation process S2.

[0016] Figure 9 is a cross-sectional view illustrating the resist pattern formation process S3.

[0017] Figure 10 is a cross-sectional view illustrating the electroplating process S4.

[0018] Figure 11 It is a cross-sectional view illustrating the resist pattern removal process S5.

[0019] Figure 12 It is a first top view of the coil device 200.

[0020] Figure 13 It is a second top view of the coil device 200.

[0021] Figure 14 It is Figure 12 a cross-sectional view taken along XIV-XIV in

[0022] Figure 15 It is a cross-sectional view of the coil device 200 according to the modified example. Detailed Embodiment

[0023] [Technical Problem to be Solved by the Present Disclosure]

[0024] There is still room for improvement in the thrust generated by the magnet in the coil device described in Patent Document 1. In addition, in the coil device described in Patent Document 1, the size of the coil in the second direction is large.

[0025] The present disclosure has been made in view of the problems of the prior art as described above. More specifically, the present disclosure provides a coil device capable of improving the thrust on the magnet and reducing the size.

[0026] [Effects of the Present Disclosure]

[0027] According to the coil device of the present disclosure, the thrust on the magnet can be improved, and the size in the second direction can be reduced.

[0028] [Description of Embodiments of the Present Disclosure]

[0029] First, the embodiments of the present disclosure will be listed and described.

[0030] (1) The coil device according to the embodiment includes at least one printed wiring board. Each of the at least one printed wiring board has: a first base film having a first main surface and a second main surface, the second main surface being the surface opposite to the first main surface; and a first wiring disposed on the first main surface. The first wiring has a plurality of first coil portions arranged in a first direction in a plan view. Each of the plurality of first coil portions is constituted by a first wiring wound in a spiral shape in a plan view and has a first straight portion, a second straight portion, a first connecting portion, and a second connecting portion. In a plan view, the first wiring located at the first straight portion and the first wiring located at the second straight portion extend in a second direction orthogonal to the first direction. The first straight portion has a first end portion and a second end portion, the first end portion and the second end portion being both end portions in the second direction. The second straight portion has a third end portion and a fourth end portion, the third end portion and the fourth end portion being both end portions in the second direction. The first connecting portion connects the first end portion and the third end portion. The second connecting portion connects the second end portion and the fourth end portion. The sum of the width of the first connecting portion in the second direction and the width of the second connecting portion in the second direction is smaller than the sum of the width of the first straight portion in the first direction and the width of the second straight portion in the first direction. According to the coil device of the above (1), the thrust on the magnet can be improved, and the size in the second direction can be reduced.

[0031] (2) In the coil device of the above (1), in a plan view, the first wiring located at the first connecting portion and the first wiring located at the second connecting portion may also extend in the first direction. According to the coil device of the above (2), the size in the second direction can be further reduced.

[0032] (3) In the coil device of the above (1) or (2), the width of the first wiring located at the first connecting portion in the second direction and the width of the first wiring located at the second connecting portion in the second direction may also be smaller than the width of the first wiring located at the first straight portion in the first direction and the width of the first wiring located at the second straight portion in the first direction.

[0033] (4) In the coil device of the above (1) to (3), the distance between two portions of the first wiring adjacent to each other in the first connecting portion and the distance between two portions of the first wiring adjacent to each other in the second connecting portion may also be equal to the distance between two portions of the first wiring adjacent to each other in the first straight portion and the distance between two portions of the first wiring adjacent to each other in the second straight portion. According to the coil device of the above (4), the first wiring can be easily formed.

[0034] (5) In the coil device of (1) to (4) above, each of at least one printed wiring board may also have a second wiring disposed on the second main surface. The second wiring may also have a plurality of second coil portions arranged in the first direction in a plan view. Each of the plurality of second coil portions may also be constituted by a second wiring wound in a spiral shape in a plan view, and have a third straight portion, a fourth straight portion, a third connection portion, and a fourth connection portion. In a plan view, the second wiring located at the third straight portion and the second wiring located at the fourth straight portion may extend in the second direction. The third straight portion may also have a fifth end portion and a sixth end portion, and the fifth end portion and the sixth end portion are both end portions in the second direction. The fourth straight portion may also have a seventh end portion and an eighth end portion, and the seventh end portion and the eighth end portion are both end portions in the second direction. The third connection portion may connect the fifth end portion and the seventh end portion. The fourth connection portion may connect the sixth end portion and the eighth end portion. The width of the third connection portion in the second direction and the width of the fourth connection portion in the second direction may be smaller than the width of the third straight portion in the first direction and the width of the fourth straight portion in the first direction. According to the coil device of (5) above, the thrust force on the magnet can be further improved.

[0035] (6) In the coil device of (1) to (5) above, at least one printed wiring board may also be a plurality of printed wiring boards.

[0036] (7) In the coil device of (6) above, the plurality of printed wiring boards may also include a first printed wiring board and a second printed wiring board that overlap each other. The second main surface of the second printed wiring board may face the first main surface of the first printed wiring board. The first straight portion of the second printed wiring board may overlap the second straight portion of the first printed wiring board in a plan view. According to the coil device of (7) above, the coils can be densely arranged in the first direction.

[0037] [Details of Embodiments of the Present Disclosure]

[0038] 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 repeated descriptions will not be repeated.

[0039] (First Embodiment)

[0040] Hereinafter, the coil device according to the first embodiment will be described. The coil device according to the first embodiment is set as the coil device 100.

[0041] [Configuration of Coil Device 100]

[0042] Hereinafter, the configuration of the coil device 100 will be described.

[0043] Figure 1is the first top view of the coil device 100. Figure 2 is the second top view of the coil device 100. It should be noted that Figure 2 the viewing direction of the surface is the same as that of Figure 1 the same. Figure 3 is Figure 1 the sectional view taken along line III-III in Figures 1 to 3 As shown, the coil device 100 has a printed wiring board 10. The printed wiring board 10 has a base film 11, a first wiring 12, and a second wiring 13.

[0044] The constituent material of the base film 11 is a flexible electrical insulating material. As a specific example of the constituent material of the base film 11, polyimide can be cited. The base film 11 has a first main surface 11a and a second main surface 11b. The first main surface 11a and the second main surface 11b are end faces in the thickness direction of the base film 11. The second main surface 11b is a surface opposite to the first main surface 11a.

[0045] The first wiring 12 is disposed on the first main surface 11a. The first wiring 12 has a plurality of first coils 14. The plurality of first coils 14 are arranged in a first direction DR1 in a top view. The first direction DR1 corresponds to the length direction of the base film 11 in a top view. The first coil 14 is formed by winding the first wiring 12 in a spiral shape in a top view.

[0046] The first coil 14 has a first straight portion 14a, a second straight portion 14b, a first connecting portion 14c, and a second connecting portion 14d. The first wiring 12 located at the first straight portion 14a and the first wiring 12 located at the second straight portion 14b extend in a second direction DR2 in a top view. The second direction DR2 is a direction orthogonal to the first direction DR1 in a top view.

[0047] The first straight portion 14a has a first end 14aa and a second end 14ab in the second direction DR2. The first end 14aa and the second end 14ab are both ends of the first straight portion 14a in the second direction DR2. The second straight portion 14b has a third end 14ba and a fourth end 14bb in the second direction DR2. The third end 14ba and the fourth end 14bb are both ends of the second straight portion 14b in the second direction DR2. The first end 14aa and the third end 14ba are opposed to each other in the first direction DR1. The second end 14ab and the fourth end 14bb are opposed to each other in the first direction DR1.

[0048] Preferably, the first wiring 12 located at the first connection portion 14c and the first wiring 12 located at the second connection portion 14d extend along the first direction DR1 in a top view. That is, preferably, the first coil 14 is rectangular in a top view. The first connection portion 14c connects the first end portion 14aa and the third end portion 14ba. The second connection portion 14d connects the second end portion 14ab and the fourth end portion 14bb.

[0049] Let the width of the first straight portion 14a in the first direction DR1 be the width W1, and let the width of the second straight portion 14b in the first direction DR1 be the width W2. Let the width of the first connection portion 14c in the second direction DR2 be the width W3, and let the width of the second connection portion 14d in the second direction DR2 be the width W4. The sum of the width W3 and the width W4 is smaller than the sum of the width W1 and the width W2. Preferably, each of the width W3 and the width W4 is smaller than the width W1 and smaller than the width W2. It should be noted that preferably, the width of the first coil 14 in the second direction DR2 is larger than the width of the first coil 14 in the first direction DR1.

[0050] Let the width of the first wiring 12 located at the first straight portion 14a in the first direction DR1 be the width W5. Let the width of the first wiring 12 located at the second straight portion 14b in the first direction DR1 be the width W6. Let the width of the first wiring 12 located at the first connection portion 14c in the second direction DR2 be the width W7. Let the width of the first wiring 12 located at the second connection portion 14d in the second direction DR2 be the width W8. Preferably, the width W7 and the width W8 are smaller than the width W5 and the width W6.

[0051] Let the distance between adjacent portions of two first wirings 12 in the first straight portion 14a be the distance DIS1, and let the distance between adjacent portions of two first wirings 12 in the second straight portion 14b be the distance DIS2. Let the distance between adjacent portions of two first wirings 12 in the first connection portion 14c be the distance DIS3, and let the distance between adjacent portions of two first wirings 12 in the second connection portion 14d be the distance DIS4. Preferably, the distance DIS1, the distance DIS2, the distance DIS3, and the distance DIS4 are equal to each other.

[0052] It should be noted that if the average value obtained by measuring one of the distance DIS1, the distance DIS2, the distance DIS3, and the distance DIS4 at ten locations is 0.95 times or more and 1.05 times or less of the average value obtained by measuring another of the distance DIS1, the distance DIS2, the distance DIS3, and the distance DIS4 at ten locations, then it is regarded that the one and the other are equal to each other.

[0053] The second wiring 13 is disposed on the second main surface 11b. The second wiring 13 has a plurality of second coils 15. The plurality of second coils 15 are arranged along the first direction DR1 in a plan view. The second coil 15 is formed by winding the second wiring 13 in a spiral shape in a plan view.

[0054] The second coil 15 has a third straight portion 15a, a fourth straight portion 15b, a third connecting portion 15c, and a fourth connecting portion 15d. The second wiring 13 located at the third straight portion 15a and the second wiring 13 located at the fourth straight portion 15b extend along the second direction DR2 in a plan view.

[0055] The third straight portion 15a has a fifth end 15aa and a sixth end 15ab in the second direction DR2. The fifth end 15aa and the sixth end 15ab are both ends of the third straight portion 15a in the second direction DR2. The fourth straight portion 15b has a seventh end 15ba and an eighth end 15bb in the second direction DR2. The seventh end 15ba and the eighth end 15bb are both ends of the fourth straight portion 15b in the second direction DR2. The fifth end 15aa and the seventh end 15ba are opposed to each other in the first direction DR1. The sixth end 15ab and the eighth end 15bb are opposed to each other in the first direction DR1.

[0056] Preferably, the second wiring 13 located at the third connecting portion 15c and the second wiring 13 located at the fourth connecting portion 15d extend along the first direction DR1 in a plan view. That is, preferably, the second coil 15 is rectangular in a plan view. The third connecting portion 15c connects the fifth end 15aa and the seventh end 15ba. The fourth connecting portion 15d connects the sixth end 15ab and the eighth end 15bb.

[0057] Let the width of the third straight portion 15a in the first direction DR1 be width W9, and let the width of the fourth straight portion 15b in the first direction DR1 be width W10. Let the width of the third connecting portion 15c in the second direction DR2 be width W11, and let the width of the fourth connecting portion 15d in the second direction DR2 be width W12. The sum of width W11 and width W12 is smaller than the sum of width W9 and width W10. Preferably, each of width W11 and width W12 is smaller than width W9 and width W10. It should be noted that preferably, the width of the second coil 15 in the second direction DR2 is larger than the width of the second coil 15 in the first direction DR1.

[0058] Let the width of the second wiring 13 in the third straight portion 15a in the first direction DR1 be width W13, and let the width of the second wiring 13 in the fourth straight portion 15b in the first direction DR1 be width W14. Let the width of the second wiring 13 in the third connecting portion 15c in the second direction DR2 be width W15, and let the width of the second wiring 13 in the fourth connecting portion 15d in the second direction DR2 be width W16. Preferably, width W15 and width W16 are smaller than width W13 and width W14.

[0059] Let the distance between portions of two adjacent second wirings 13 in the third straight portion 15a be distance DIS5, and let the distance between portions of two adjacent second wirings 13 in the fourth straight portion 15b be distance DIS6. Let the distance between portions of two adjacent second wirings 13 in the third connecting portion 15c be distance DIS7, and let the distance between portions of two adjacent second wirings 13 in the fourth connecting portion 15d be distance DIS8. Preferably, distance DIS5, distance DIS6, distance DIS7, and distance DIS8 are equal to each other.

[0060] It should be noted that if the average value obtained by measuring one of distance DIS5, distance DIS6, distance DIS7, and distance DIS8 at ten locations is 0.95 times or more and 1.05 times or less of the average value obtained by measuring another of distance DIS5, distance DIS6, distance DIS7, and distance DIS8 at ten locations, then it is regarded that the one and the other are equal to each other.

[0061] When viewed from above, the plurality of first coils 14 each overlap with the plurality of second coils 15. The first coil 14 and the second coil 15 that overlap each other when viewed from above are electrically connected. More specifically, the pad portion at the innermost circumference of the first coil 14 is electrically connected to the pad portion at the innermost circumference of the second coil 15. Thus, the first coil 14 and the second coil 15 that overlap each other when viewed from above function as one coil.

[0062] The plurality of first coils 14 include a plurality of first coils 14e, a plurality of first coils 14f, and a plurality of first coils 14g. The first coil 14e, the first coil 14f, and the first coil 14g are arranged in sequence along the first direction DR1. The plurality of first coils 14e are electrically connected to each other, the plurality of first coils 14f are electrically connected to each other, and the plurality of first coils 14g are electrically connected to each other.

[0063] The base film 11 is wound into a cylindrical shape along the first direction DR1. Thus, the coil device 100 becomes the stator of a motor. At this time, currents with phase shifts flow through the plurality of first coils 14e, the plurality of first coils 14f, and the plurality of first coils 14g, respectively.

[0064] The first wiring 12 and the second wiring 13 each have, for example, a seed layer 16, a conductive layer 17, and an electrolytic plating layer 18. The seed layer 16 is disposed on the main surfaces (the first main surface 11a and the second main surface 11b) of the base film 11. The constituent material of the seed layer 16 is, for example, a nickel-chromium alloy.

[0065] The conductive layer 17 is disposed on the seed layer 16. The conductive layer 17 is, for example, a layer formed by sputtering. The constituent material of the conductive layer 17 is, for example, copper. The electrolytic plating layer 18 is disposed on the conductive layer 17. The electrolytic plating layer 18 is a layer formed by electrolytic plating. The constituent material of the electrolytic plating layer 18 is, for example, copper.

[0066] It should be noted that, although not shown, through holes 11c are formed in the base film 11. The through holes 11c overlap, in a plan view, with the pad portions located at the innermost circumference of the first coil 14 and the pad portions located at the innermost circumference of the second coil 15. The conductive layer 17 is also disposed on the inner wall surfaces of the through holes 11c and on the side surfaces of the seed layer 16 connected to the inner wall surfaces of the through holes 11c. Thereby, the first coil 14 and the second coil 15 that overlap in a plan view are electrically connected.

[0067] <Modification 1>

[0068] Figure 4 is a first top view of the coil device 100 according to Modification 1. Figure 5 is a second top view of the coil device 100 according to Modification 1. It should be noted that Figure 5 the surface viewing direction of Figure 4 is the same as Figure 4 and Figure 5 As shown in

[0069] <Modification 2>

[0070] In the above description, the case where the coil device 100 has both the first wiring 12 (a plurality of first coils 14) and the second wiring 13 (a plurality of second coils 15) has been described, but the coil device 100 may not have one of the first wiring 12 (a plurality of first coils 14) and the second wiring 13 (a plurality of second coils 15).

[0071] <Method for manufacturing coil device 100>

[0072] Hereinafter, a method for manufacturing the coil device 100 will be described.

[0073] Figure 6 It is a manufacturing process diagram of the coil device 100. As Figure 6 shown, the manufacturing method of the coil device 100 has a preparation process S1, a conductive layer formation process S2, a resist pattern formation process S3, an electrolytic plating process S4, a resist pattern removal process S5, and an etching process S6.

[0074] Figure 7 It is a cross-sectional view illustrating the preparation process S1. As Figure 7 shown, in the preparation process S1, a base film 11 is prepared. In the base film 11 prepared in the preparation process S1, a seed layer 16 is disposed on the first main surface 11a and the second main surface 11b.

[0075] Figure 8 It is a cross-sectional view illustrating the conductive layer formation process S2. As Figure 8 shown, in the conductive layer formation process S2, a conductive layer 17 is formed on the seed layer 16 by, for example, sputtering. It should be noted that since a through-hole 11c is formed in the base film 11 before the conductive layer formation process S2, the conductive layer 17 is also formed on the inner wall surface of the through-hole 11c and the side surface of the seed layer 16 connected to the inner wall surface of the through-hole 11c.

[0076] Figure 9 It is a cross-sectional view illustrating the resist pattern formation process S3. As Figure 9 shown, in the resist pattern formation process S3, a resist pattern 20 is formed on the conductive layer 17. The resist pattern 20 has an opening 21. The conductive layer 17 is exposed from the opening 21. The resist pattern 20 is formed, for example, by pasting a dry film resist on the conductive layer 17 and performing exposure and development on the pasted dry film resist.

[0077] Figure 10 It is a cross-sectional view illustrating the electrolytic plating process S4. As Figure 10 shown, in the electrolytic plating process S4, an electrolytic plating layer 18 is formed on the conductive layer 17 exposed from the opening 21 by performing electrolytic plating. Figure 11 It is a cross-sectional view illustrating the resist pattern removal process S5. As Figure 11 shown, in the resist pattern removal process S5, the resist pattern 20 is removed.

[0078] In the etching process S6, the conductive layer 17 and the seed layer 16 located under the resist pattern 20 are removed by etching. Through the above processes, Figures 1 to 3The coil device 100 of the structure shown.

[0079] <Effect of the coil device 100>

[0080] Hereinafter, the effect of the coil device 100 will be described.

[0081] In the coil device 100, since the first wiring 12 located in the first straight portion 14a and the first wiring 12 located in the second straight portion 14b extend along the second direction DR2 in a top view, the thrust on the magnet is increased as compared with the case where the extending directions of the first wiring 12 located in the first straight portion 14a and the first wiring 12 located in the second straight portion 14b are inclined with respect to the second direction DR2 in a top view.

[0082] Increasing the number of turns of the first wiring 12 constituting the first coil 14 is effective for the thrust of the coil device 100. However, if the first wiring 12 is wound in the same way in the first straight portion 14a and the second straight portion 14b and the first connecting portion 14c and the second connecting portion 14d, as the number of turns of the first wiring 12 constituting the first coil 14 increases, the size of the first coil 14 in the second direction DR2, and thus the size of the coil device 100 in the second direction DR2, increases.

[0083] In the coil device 100, the first wiring 12 constituting the first coil 14 is wound such that the sum of the width W3 and the width W4 is smaller than the sum of the width W1 and the width W2. For this reason, even if the number of turns of the first wiring 12 constituting the first coil 14 increases, an increase in the size of the first coil 14 in the second direction DR2 is suppressed. Thus, according to the coil device 100, it is possible to improve the thrust on the magnet while suppressing an increase in the size in the second direction DR2.

[0084] When the first wiring 12 located in the first connecting portion 14c and the first wiring 12 located in the second connecting portion 14d extend along the first direction DR1 in a top view, the width W3 and the width W4 can be minimized, so that an increase in the size of the coil device 100 in the second direction DR2 can be further suppressed.

[0085] When the distances DIS1, DIS2, DIS3, and DIS4 are equal to each other, that is, when the sum of the width W3 and the width W4 is smaller than the sum of the width W1 and the width W2 by making the width W7 and the width W8 smaller than the width W5 and the width W6, since the pattern width of the resist pattern 20 becomes constant, the formation and removal of the resist pattern 20 become easy. For this reason, in this case, the first wiring 12 can be easily formed.

[0086] When the coil device 100 has the second wiring 13 (a plurality of second coils 15), the mutually overlapping first coil 14 and second coil 15 function as one coil. For this reason, in this case, the thrust force on the magnet can be further increased.

[0087] (Second Embodiment)

[0088] Hereinafter, the coil device according to the second embodiment will be described. The coil device according to the second embodiment is designated as the coil device 200. Here, mainly the points different from the coil device 100 will be described, and repeated descriptions will not be made.

[0089] <Configuration of Coil Device 200>

[0090] Hereinafter, the configuration of the coil device 200 will be described.

[0091] Figure 12 is the first top view of the coil device 200. Figure 13 is the second top view of the coil device 200. It should be noted that Figure 13 The viewing direction of the surface is the same as that of Figure 12 the same. Figure 14 is Figure 12 The cross-sectional view taken along the line XIV-XIV in Figures 12 to 14 As shown, the coil device 200 has a plurality of printed wiring boards 10. Preferably, the number of the plurality of printed wiring boards 10 is an even number. In Figures 12 to 14 In the example shown, the number of the plurality of printed wiring boards 10 is two. These two printed wiring boards 10 are designated as the printed wiring board 10A and the printed wiring board 10B. It should be noted that the number of the plurality of printed wiring boards 10 may also be an even number of 4 or more.

[0092] The first main surface 11a of the printed wiring board 10A faces the second main surface 11b of the printed wiring board 10B. The adhesive layer 30 is interposed between the printed wiring board 10A and the printed wiring board 10B. Thereby, the printed wiring board 10A and the printed wiring board 10B are adhesively bonded to each other.

[0093] The printed wiring board 10A and the printed wiring board 10B are arranged such that, when viewed from above, the first straight portion 14a and the second straight portion 14b of the printed wiring board 10B respectively overlap the second straight portion 14b and the first straight portion 14a of the printed wiring board 10A. For example, the first straight portion 14a of the first coil 14e of the printed wiring board 10B overlaps the second straight portion 14b of the first coil 14e of the printed wiring board 10A, and the second straight portion 14b of the first coil 14e of the printed wiring board 10B overlaps the first straight portion 14a of the first coil 14f of the printed wiring board 10A.

[0094] <Modification Example>

[0095] Figure 15 This is a cross-sectional view of the coil device 200 according to the modified example. As Figure 15 shown, the number of the plurality of printed wiring boards 10 may also be an odd number. In Figure 15 the example shown, the number of the plurality of printed wiring boards 10 is three. These three printed wiring boards 10 are designated as printed wiring board 10A, printed wiring board 10B, and printed wiring board 10C. However, the number of the plurality of printed wiring boards 10 may also be an odd number of 5 or more.

[0096] The first straight portion 14a of the printed wiring board 10B overlaps with the second straight portion 14b of the printed wiring board 10C when viewed from above. The second straight portion 14b of the printed wiring board 10B overlaps with the first straight portion 14a of the printed wiring board 10A when viewed from above. Although not shown, the first straight portion 14a of the printed wiring board 10C overlaps with the second straight portion 14b of the printed wiring board 10A when viewed from above.

[0097] In other words, when the number of the plurality of printed wiring boards 10 is an odd number, the interval between two adjacent first coils 14 (second coils 15) becomes larger as compared with the case where the number of the plurality of printed wiring boards 10 is an even number.

[0098] <Effects of the coil device 200>

[0099] In the coil device 200, since the first straight portion 14a and the second straight portion 14b of the printed wiring board 10B overlap with the second straight portion 14b and the first straight portion 14a of the printed wiring board 10A, respectively, when viewed from above, coils can be arranged more densely in the first direction DR1.

[0100] It should be considered that the embodiments disclosed herein are illustrative in all aspects and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0101] Description of reference numerals

[0102] 10: Printed wiring board; 10A: Printed wiring board; 10B: Printed wiring board; 10C: Printed wiring board; 11: Base film; 11a: First main surface; 11b: Second main surface; 11c: Through hole; 12: First wiring; 13: Second wiring; 14: First coil; 14a: First straight portion; 14aa: First end portion; 14ab: Second end portion; 14b: Second straight portion; 14ba: Third end portion; 14bb: Fourth end portion; 14c: First connection portion; 14d: Second connection portion; 14e, 14f, 14g: First coil; 15: Second coil; 15a: Third straight portion; 15aa: Fifth end portion; 15ab: Sixth end portion; 15b: Fourth straight portion; 15ba: Seventh end portion; 15bb: Eighth end portion; 15c: Third connection portion; 15d: Fourth connection portion; 16: Seed layer; 17: Conductive layer; 18: Electrolytic plating layer; 20: Resist pattern; 21: Opening; 30: Adhesive layer; 100, 200: Coil device; DIS1, DIS2, DIS3, DIS4, DIS5, DIS6, DIS7, DIS8: Distance; DR1: First direction; DR2: Second direction; S1: Preparation process; S2: Conductive layer formation process; S3: Resist pattern formation process; S4: Electrolytic plating process; S5: Resist pattern removal process; S6: Etching process; W1, W2, W3, W4, W5, W6, W7, W8, W9, W10, W11, W12, W13, W14, W15, W16: Width.

Claims

1. A coil device includes at least one printed wiring board, wherein each of the at least one printed wiring board has: a first base film having a first main surface and a second main surface, the second main surface being a surface opposite to the first main surface; and a first wiring disposed on the first main surface, the first wiring having a plurality of first coil portions arranged in a first direction in a plan view, each of the plurality of first coil portions being constituted by the first wiring wound in a spiral shape in a plan view and having a first straight portion, a second straight portion, a first connection portion, and a second connection portion, in the plan view, the first wiring located at the first straight portion and the first wiring located at the second straight portion extend in a second direction orthogonal to the first direction, the first straight portion having a first end portion and a second end portion, the first end portion and the second end portion being both end portions in the second direction, the second straight portion having a third end portion and a fourth end portion, the third end portion and the fourth end portion being both end portions in the second direction, the first connection portion connecting the first end portion and the third end portion, the second connection portion connecting the second end portion and the fourth end portion, the sum of the widths of the first connection portion and the second connection portion in the second direction being smaller than the sum of the widths of the first straight portion and the second straight portion in the first direction.

2. The coil device according to claim 1, wherein, in the plan view, the first wiring located at the first connection portion and the first wiring located at the second connection portion extend in the first direction.

3. The coil device according to claim 2, wherein, the widths of the first wiring located at the first connection portion and the first wiring located at the second connection portion in the second direction are smaller than the widths of the first wiring located at the first straight portion and the first wiring located at the second straight portion in the first direction.

4. The coil device according to claim 1, wherein, the distance between two adjacent portions of the first wiring in the first connection portion and the distance between two adjacent portions of the first wiring in the second connection portion are less than or equal to the distance between two adjacent portions of the first wiring in the first straight portion and the distance between two adjacent portions of the first wiring in the second straight portion.

5. The coil device according to claim 2, wherein, the distance between two adjacent portions of the first wiring in the first connection portion and the distance between two adjacent portions of the first wiring in the second connection portion are less than or equal to the distance between two adjacent portions of the first wiring in the first straight portion and the distance between two adjacent portions of the first wiring in the second straight portion.

6. The coil device according to claim 3, wherein, The distance between two adjacent portions of the first wiring in the first connecting portion and the distance between two adjacent portions of the first wiring in the second connecting portion are less than the distance between two adjacent portions of the first wiring in the first straight portion and the distance between two adjacent portions of the first wiring in the second straight portion.

7. The coil device according to claim 1, wherein, each of the at least one printed wiring board further has a second wiring disposed on the second main surface, the second wiring has a plurality of second coil portions arranged in the first direction in a top view, each of the plurality of second coil portions is constituted by the second wiring wound in a spiral shape in a top view, and has a third straight portion, a fourth straight portion, a third connecting portion, and a fourth connecting portion, in a top view, the second wiring located in the third straight portion and the second wiring located in the fourth straight portion extend in the second direction, the third straight portion has a fifth end portion and a sixth end portion, and the fifth end portion and the sixth end portion are both end portions in the second direction, the fourth straight portion has a seventh end portion and an eighth end portion, and the seventh end portion and the eighth end portion are both end portions in the second direction, the third connecting portion connects the fifth end portion and the seventh end portion, the fourth connecting portion connects the sixth end portion and the eighth end portion, the sum of the widths of the third connecting portion and the fourth connecting portion in the second direction is smaller than the sum of the widths of the third straight portion and the fourth straight portion in the first direction.

8. The coil device according to any one of claims 1 to 7, wherein, the at least one printed wiring board is a plurality of printed wiring boards.

9. The coil device according to claim 8, wherein, the plurality of printed wiring boards include a first printed wiring board and a second printed wiring board that overlap each other, the second main surface of the second printed wiring board faces the first main surface of the first printed wiring board, the first straight portion of the second printed wiring board overlaps the second straight portion of the first printed wiring board in a top view.

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