Coil substrate and motor coil substrate

Abstract

To provide a coil substrate having a great space factor.SOLUTION: A coil substrate 10 includes a flexible substrate 22 that has one end 22L and the other end 22R, and a coil C that is formed on the flexible substrate. At least three coils C partially overlap one another.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a coil substrate and a motor coil substrate.

Background Art

[0002] Patent Document 1 discloses a motor coil substrate having a flexible insulating substrate and a coil.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

[0004] [Problems of the Patent Document] FIG. 5 of Patent Document 1 shows the arrangement of coils. According to FIG. 5 of Patent Document 1, coil C1 and coil C2 partially overlap. Coil C1 and coil C3 do not overlap. Therefore, it is considered difficult to increase the occupation ratio of the coils using the technology of Patent Document 1. In the motor coil substrate of Patent Document 1, the flexible insulating substrate is wound. The number of turns of the flexible insulating substrate exceeds one rotation. Therefore, the motor coil substrate of Patent Document 1 is considered to include at least a first turn of flexible insulating substrate (first flexible insulating substrate) and a second turn of flexible insulating substrate (second flexible insulating substrate) wound outside the first flexible insulating substrate. The first portion of the second flexible insulating substrate extends from the last portion of the first flexible insulating substrate. The second flexible insulating substrate is wound around the first flexible insulating substrate. When the flexible insulating substrate is wound so that the shape of the flexible insulating substrate becomes cylindrical, it is considered that the distance between the center of the cylinder and the first portion of the first flexible insulating substrate is different from the distance between the center of the cylinder and the last portion of the first flexible insulating substrate. In the technology of Patent Document 1, it is considered that the positions of the coils formed on the first portion of the first flexible insulating substrate do not match the positions of the coils formed on the first portion of the second flexible insulating substrate. When a motor is formed using the technology of Patent Document 1, it is considered difficult to provide a motor having high performance. [Means for Solving the Problems]

[0005] The coil substrate according to the present invention includes a flexible substrate including a first flexible substrate having one end and a second flexible substrate extending from the first flexible substrate, and a plurality of coils formed on the flexible substrate. The coils are arranged substantially in a line, and the coils include an m-th coil, an (m + 1)-th coil, an (m + 2)-th coil, an (m + 3)-th coil, and an (m + 4)-th coil. The (m + 1)-th coil is located next to the m-th coil, the (m + 2)-th coil is located next to the (m + 1)-th coil, the (m + 3)-th coil is located next to the (m + 2)-th coil, the (m + 4)-th coil is located next to the (m + 3)-th coil, the m-th coil, the (m + 1)-th coil, and the (m + 2)-th coil partially overlap, and the m-th coil and the (m + 4)-th coil do not overlap. m is a natural number.

[0006] [Effects of the Embodiment] The coil substrate according to an embodiment of the present invention is formed of a flexible substrate including a first flexible substrate and a second flexible substrate extending from the first flexible substrate, and a plurality of coils formed on the flexible substrate. The m-th coil, the (m + 1)-th coil, and the (m + 2)-th coil partially overlap. According to the embodiment, at least three coils overlap. Therefore, the occupation ratio of the coils can be increased. A motor coil substrate can be manufactured by winding the coil substrate of the embodiment. The second flexible substrate is wound around the first flexible substrate. The first flexible substrate forms the first turn, and the second flexible substrate forms the second turn. The coils on the first flexible substrate are inner coils, and the coils on the second flexible substrate are outer coils. The number of inner coils (the first number) and the number of outer coils (the second number) are plural, and the first number and the second number are the same. The inner coils have a first inner coil closest to one end of the first flexible substrate and a last inner coil closest to the second flexible substrate. The last inner coil has a second width, and the first inner coil has a first width. And the second width is larger than the first width. By adjusting the second width, the length of the first flexible substrate can be adjusted. By adjusting the second width, the position of the coils in the motor coil substrate can be adjusted. According to the embodiment, the positions of the inner coils and the outer coils can be aligned with high accuracy. A motor coil substrate having high performance can be provided.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiment for Carrying Out the Invention

[0008] [Embodiment] The coil substrate 10 shown in FIG. 4(A) is prepared. The coil substrate 10 is formed of a flexible substrate 22 having a first surface F and a second surface S opposite to the first surface F, and coils C (C1 to C9) on the flexible substrate 22. The flexible substrate 22 has one end 22L and the other end 22R. The coils C in FIG. 4 are schematically shown. By winding the coil substrate 10, the motor coil substrate 20 shown in FIG. 1(B) is obtained. For example, the coil substrate 10 is wound into a cylindrical shape. The motor coil substrate 20 is wound around the cavity AH. The coil substrate 10 is wound so that the first surface F faces the cavity AH. For example, the shape of the motor coil substrate 20 is cylindrical. The number of winding turns N is 2 or more and 5 or less. FIG. 1(B) is a schematic diagram.

[0009] As shown in FIG. 1(A), by disposing the magnet 48 inside the motor coil substrate 20, the motor 110 is obtained. FIG. 1(A) is a schematic diagram. The motor coil substrate 20 is disposed around the magnet 48 via the cavity AH. An example of the motor 110 is a brushless motor. In the embodiment, the magnet 48 rotates, but the motor coil substrate 20 may also rotate.

[0010] An example of the coil C is shown in FIG. 1(C). The coil C is formed of a central space SC and wiring w surrounding the central space SC. The wiring w has an output portion OE and an input portion IE. The wiring w is formed between the output portion OE and the input portion IE. The wiring w forming the coil C is formed in a spiral shape. The central space SC is surrounded by the innermost wiring Iw among the wirings w forming the coil C. The outermost wiring w is the outer wiring Ow. The wiring w forming the coil C is formed around the central space SC.

[0011] The wiring w forming the coil C in FIG. 1(C) is drawn with solid lines, dashed lines, and circles. The solid lines indicate the wiring (first-side wiring) wf on the first surface F. The dashed lines indicate the wiring (second-side wiring) ws on the second surface S. The circles indicate via conductors V. The via conductors V connect the first-side wiring wf and the second-side wiring ws. The via conductors V include a first via conductor V1 that connects the first-side wiring wf and the second-side wiring ws within one turn and a second via conductor V2 that connects different turns. One first-side wiring wf, one first via conductor V1, and one second-side wiring ws form one turn.

[0012] As shown in FIG. 1(C), the wiring w includes a plurality of first wirings 51 and a plurality of second wirings 52 facing each other via a central space SC. Within one coil C, the first wiring 51 is close to one end 22L, and the second wiring 52 is close to the other end 22R. Each of the first wirings 51 is formed substantially in parallel. Each of the second wirings 52 is formed substantially in parallel. The first wiring 51 and the second wiring 52 are formed substantially in parallel. When the motor 110 is manufactured using the coil substrate 10 of the embodiment, the angle between the rotation direction MR of the motor shown in FIG. 1(B) and the first wiring 51 is approximately 90 degrees. The angle between the direction of the current flowing through the first wiring 51 and the rotation direction MR of the motor is approximately 90 degrees. The wiring w further has a third wiring 53 connecting the first wiring 51 and the second wiring 52.

[0013] Among the plurality of first wirings 51, the outermost first wiring 51 is the outer first wiring 51Ow. Among the plurality of first wirings 51, the innermost wiring is the inner first wiring 51Iw. The inner first wiring 51Iw faces the central space SC. Among the plurality of second wirings 52, the outermost second wiring 52 is the outer second wiring 52Ow. Among the plurality of second wirings 52, the innermost second wiring 52 is the inner second wiring 52Iw. The inner second wiring 52Iw faces the central space SC.

[0014] FIG. 1(E) is a cross-sectional view of one coil C. FIG. 1(E) shows the cross-sections of the first wiring 51 and the second wiring 52.

[0015] FIG. 1(D) schematically shows the coil C. In FIG. 1(D), the wirings w are bundled. When the wirings w are bundled, a wiring group is formed. By bundling the first wirings 51, the first wiring group 51g is formed. The first wiring group 51g is formed by all the first wirings 51. By bundling the second wirings 52, the second wiring group 52g is formed. The second wiring group 52g is formed by all the second wirings 52. In FIG. 1(D), the coil C is drawn using the wiring group. The wiring group on the first surface F is drawn as a horizontal line. The wiring group on the second surface S is drawn as a slanted line. The coil C in FIG. 4(A) is drawn using the wiring group.

[0016] As shown in FIG. 4(A), the flexible substrate 22 has a short side 20S and a long side 20L. The flexible substrate 22 has one end 22L and the other end 22R on the side opposite to the one end 22L. The short side 20S also serves as one end 22L. The coils C (C1 to C9) are arranged along the long side 20L of the flexible substrate 22. The coils C are arranged in almost a single row from one end 22L to the other end 22R of the flexible substrate 22. The coil C closest to the one end 22L is the first coil C1. The next after the first coil C1 is the second coil C2. The next after the second coil C2 is the third coil C3. The next after the third coil C3 is the fourth coil C4. The next after the fourth coil C4 is the fifth coil C5. Thus, the (m + 1)-th coil is located next to the m-th coil. The (m + 2)-th coil is located next to the (m + 1)-th coil. The (m + 3)-th coil is located next to the (m + 2)-th coil. The (m + 4)-th coil is located next to the (m + 3)-th coil. The first coil C1, the second coil C2, and the third coil C3 partially overlap. The first coil C1 and the fifth coil C5 do not overlap. Thus, the m-th coil, the (m + 1)-th coil, and the (m + 2)-th coil partially overlap. The m-th coil and the (m + 4)-th coil do not overlap. In the embodiment, three coils C overlap. Therefore, the occupation ratio of the coils can be increased. The first coil C1, the second coil C2, the third coil C3, and the fourth coil C4 partially overlap. The first coil C1 and the fifth coil C5 do not overlap. Thus, the m-th coil, the (m + 1)-th coil, the (m + 2)-th coil, and the (m + 3)-th coil partially overlap. The m-th coil and the (m + 4)-th coil do not overlap. In the embodiment, four coils C overlap. Therefore, the occupation ratio of the coils can be increased. The m-th coil is close to one end 22L, and the (m + 1)-th coil is close to the other end 22R. m is a natural number. The first coil C1 is a U-phase coil. The second coil C2 is a V-phase coil. The third coil C3 is a W-phase coil. The U-phase coil, the V-phase coil, and the W-phase coil are arranged in the order of the U-phase coil, the V-phase coil, and the W-phase coil, and the coil C closest to one end 22L is the U-phase coil. The number of coils C is a multiple of 3. In the example of FIG. 4(A), the number of coils is 9.

[0017] The coil substrate 10 is formed of one flexible substrate 22. The flexible substrate 22 forming the coil substrate 10 is divided into a plurality of parts P. Accordingly, the coil substrate 10 is also divided into a plurality of parts P. The coil substrate 10 is formed of a plurality of parts P, and the number of parts P is N. The parts P forming the coil substrate 10 are arranged in the direction from one end 22L to the other end 22R. The first part P1 includes one end 22L of the flexible substrate 22. The second part P2 is adjacent to the first part P1. For example, N is the number of turns of winding the flexible substrate 22. The N-th part PN includes the other end 22R of the flexible substrate 22.

[0018] In the example of FIG. 4(A), the number of parts P is 2. The coil substrate 10 in FIG. 4(A) is formed of the first part P1 and the second part P2. The flexible substrate 22 forming the first part P1 is the first flexible substrate 22-1. The flexible substrate 22 forming the second part P2 is the second flexible substrate 22-2. The second flexible substrate 22-2 extends from the first flexible substrate 22-1.

[0019] As shown in FIG. 4(A), the coil C includes a coil C formed in the first flexible substrate 22-1, a coil C formed in the second flexible substrate 22-2, and a coil formed on both regions of the first flexible substrate 22-1 and the second flexible substrate 22-2.

[0020] The coil C formed in the first flexible substrate 22-1 is referred to as the inner coil CI. In the case of the inner coil CI, the entire coil C is formed in the first flexible substrate 22-1. The number (first number) of the inner coils CI is plural. Among the inner coils CI, the coil C closest to the one end 22L is the first inner coil CI1. Among the inner coils CI, the coil C closest to the second flexible substrate 22-2 is the last inner coil CIE. The inner coil CI includes an intermediate inner coil CII between the first inner coil CI1 and the last inner coil CIE. The number of the intermediate inner coils CII is 1 or 4.

[0021] In the example of FIG. 4(A), the first number is 3 and the number of the intermediate inner coils CII is 1. The first inner coil CI1, the intermediate inner coil CII, and the last inner coil CIE are formed on the first flexible substrate 22-1. The first coil C1 is the first inner coil CI1. The second coil C2 is the intermediate inner coil CII. The third coil C3 is the last inner coil CIE.

[0022] The coil C formed on the second flexible substrate 22-2 is referred to as the outer coil CO. In the case of the outer coil CO, the entire coil C is formed within the second flexible substrate 22-2. The number (second number) of the outer coils CO is plural. The first number and the second number are the same. Among the outer coils CO, the coil C closest to the first flexible substrate 22-1 is the first outer coil CO1. Among the outer coils CO, the coil C closest to the other end 22R is the last outer coil COE. The outer coil CO includes an intermediate outer coil COI between the first outer coil CO1 and the last outer coil COE. The number of the intermediate outer coils COI is 1 or 4. The seventh coil C7 is the first outer coil COI. The eighth coil C8 is the intermediate outer coil COI. The ninth coil C9 is the last outer coil COE.

[0023] In the example of FIG. 4(A), the second number is 3, and the number of the intermediate outer coils COI is 1. The first outer coil CO1, the intermediate outer coil COI, and the last outer coil COE are formed on the second flexible substrate 22-2.

[0024] Each coil C has a distance (width) W shown in FIGS. 1(D) and 1(E). The first wiring 51 has a first side wall sw1 facing the central space SC and a second side wall sw2 opposite to the first side wall sw1. The second wiring 52 has a third side wall sw3 facing the central space SC and a fourth side wall sw4 opposite to the third side wall sw3. The distance between the second side wall sw2 of the outer first wiring 51Ow and the fourth side wall sw4 of the outer second wiring 52Ow among the wirings w forming one coil C is the width W. Alternatively, the width W is measured along a straight line perpendicular to the first wiring 51. Alternatively, the width W is measured along the long side 20L of the flexible substrate 22. Alternatively, two straight lines (a first straight line L1 and a second straight line L2) are prepared on the coil substrate 10 shown in FIG. 4(A). The first straight line L1 and the second straight line L2 are parallel. The angle between the first straight line L1 and the rotation direction MR of the motor 110 is approximately 90 degrees. Each coil C is sandwiched between the first straight line L1 and the second straight line L2. The distance between the first straight line L1 and the second straight line L2 sandwiching the coil C is the width W of the coil C. The first inner coil CI1 has a first width w1. The middle inner coil CII has a first width w1. The last inner coil CIE has a second width w2. For example, when the first inner coil CI1 is sandwiched between the first straight line L1 and the second straight line L2, the distance between the first straight line L1 and the second straight line L2 is the first width w1. When the last inner coil CIE is sandwiched between the first straight line L1 and the second straight line L2, the distance between the first straight line L1 and the second straight line L2 is the second width w2. When the middle inner coil CII is sandwiched between the first straight line L1 and the second straight line L2, the distance between the first straight line L1 and the second straight line L2 is the first width w1.

[0025] The central space SP of each coil C has a width. The width of the central space SP is the distance between the first side wall sw1 of the inner first wiring 51Iw and the third side wall sw3 of the inner second wiring 52Iw. Alternatively, the width is measured by sandwiching the central space SP between the first straight line and the second straight line. The distance between the first straight line and the second straight line is the width of the central space SP.

[0026] FIG. 2 shows the width W of the first inner coil CI1, the width W of the intermediate inner coil CII, and the width W of the last inner coil CIE. The width of the first inner coil CI1 (the first width w1) and the width of the intermediate inner coil CII (the first width w1) are substantially equal. The width of the last inner coil CIE (the second width w2) is greater than the first width w1.

[0027] FIG. 2(A) shows a cross-section of the first inner coil CI1. FIG. 2(B) shows a cross-section of the intermediate inner coil CII. FIG. 2(C) shows a cross-section of the last inner coil CIE. Cross-sections of the first wiring 51 and the second wiring 52 are depicted in these figures.

[0028] The first wiring 51 forming the first inner coil CI1 has a width (the first 1 width) x1. The widths x1 of each of the first wirings 51 within the first inner coil CI1 are substantially equal. A space B1 is formed between adjacent first wirings 51 within the first inner coil CI1. The space B1 has a width b1. The widths (the second 1 width) b1 of each of the spaces B1 within the first inner coil CI1 are substantially equal. The second wiring 52 forming the first inner coil CI1 has a width (the first 2 width) x2. The widths x2 of each of the second wirings 52 within the first inner coil CI1 are substantially equal. A space B2 is formed between adjacent second wirings 52 within the first inner coil CI1. The space B2 has a width (the second 2 width) b2. The widths b2 of each of the spaces B2 within the first inner coil CI1 are substantially equal.

[0029] The first wiring 51 forming the intermediate inner coil CII has a width (the first 3 width) y1. The widths y1 of each of the first wirings 51 within the intermediate inner coil CII are substantially equal. A space D1 is formed between adjacent first wirings 51 within the intermediate inner coil CII. The space D1 has a width (the second 3 width) d1. The widths d1 of each of the spaces D1 within the intermediate inner coil CII are substantially equal. The second wiring 52 forming the intermediate inner coil CII has a width (the first 4 width) y2. The widths y2 of each of the second wirings 52 within the intermediate inner coil CII are substantially equal. A space D2 is formed between adjacent second wirings 52 within the intermediate inner coil CII. The space D2 has a width (the 24th width) d2. The widths d2 of each space D2 within the intermediate inner coil CII are substantially equal.

[0030] The first wiring 51 forming the last inner coil CIE has a width (the 15th width) z1. The widths z1 of each first wiring 51 within the last inner coil CIE are substantially equal. A space Q1 is formed between adjacent first wirings 51 within the last inner coil CIE. The space Q1 has a width (the 25th width) q1. The widths q1 of each space Q1 within the last inner coil CIE are substantially equal. The second wiring 52 forming the last inner coil CIE has a width (the 16th width) z2. The widths z2 of each second wiring 52 within the last inner coil CIE are substantially equal. A space Q2 is formed between adjacent second wirings 52 within the last inner coil CIE. The space Q2 has a width (the 26th width) q2. The widths q2 of each space Q2 within the last inner coil CIE are substantially equal.

[0031] The 11th width x1, the 12th width x2, the 13th width y1, the 14th width y2, and the 15th width z1 are substantially equal. The 16th width z2 is larger than the 11th width x1. The 21st width b1, the 22nd width b2, the 23rd width d1, the 24th width d2, the 25th width q1, and the 26th width q2 are substantially equal. The width SP1 of the central space SP of the first inner coil CI1, the width SP2 of the central space SP of the intermediate inner coil CII, and the width SP3 of the central space SP of the last inner coil CIE are substantially equal. From these relationships, the width w2 of the last inner coil CIE can be made larger than the width w1 of the first inner coil CI1. The width w2 of the last inner coil CIE can be made larger than the width w1 of the intermediate inner coil CII. By adjusting the 16th width z2, the width w2 of the last inner coil CIE is adjusted. The width w1 of the first inner coil CI1 and the width w1 of the intermediate inner coil CII can be made substantially equal.

[0032] The first wiring group 51g has a width. The width of the first wiring group 51g is the distance between the second side wall sw2 of the outer first wiring 51Ow and the first side wall sw1 of the inner first wiring 51Iw. Alternatively, the width of the first wiring group 51g is measured along a straight line perpendicular to the first wiring 51. Alternatively, the width of the first wiring group 51g is measured by sandwiching the first wiring group 51g between a first straight line L1 and a second straight line L2. The distance between the first straight line L1 and the second straight line L2 is the width of the first wiring group 51g.

[0033] The second wiring group 52g has a width. The width of the second wiring group 52g is the distance between the fourth side wall sw4 of the outer second wiring 52Ow and the third side wall sw3 of the inner second wiring 52Iw. Alternatively, the width of the second wiring group 52g is measured along a straight line perpendicular to the first wiring 51. Alternatively, the width of the second wiring group 52g is measured by sandwiching the second wiring group 52g between a first straight line L1 and a second straight line L2. The distance between the first straight line L1 and the second straight line L2 is the width of the second wiring group 52g.

[0034] As shown in FIG. 2(A), the first wiring group 51g of the first inner coil CI1 has a width (the 31st width) w3 of the first wiring group. The second wiring group 52g of the first inner coil CI1 has a width (the 32nd width) w4 of the second wiring group. As shown in FIG. 2(B), the first wiring group 51g of the middle inner coil CII has a width (the 33rd width) w5 of the first wiring group. The second wiring group 52g of the middle inner coil CII has a width (the 34th width) w6 of the second wiring group. As shown in FIG. 2(C), the first wiring group 51g of the last inner coil CIE has a width (the 35th width) w7 of the first wiring group. The second wiring group 52g of the last inner coil CIE has a width (the 36th width) w8 of the second wiring group.

[0035] The 31st width w3, the 32nd width w4, the 33rd width w5, the 34th width w6, and the 35th width w7 are substantially equal. The 36th width w8 is larger than the 31st width w3. The width SP1 of the central space SP of the first inner coil CI1, the width SP2 of the central space SP of the middle inner coil CII, and the width SP3 of the central space SP of the last inner coil CIE are substantially equal. From these relationships, the width w2 of the last inner coil CIE can be made larger than the width w1 of the first inner coil CI1. By adjusting the 36th width w8, the width w2 of the last inner coil CIE is adjusted. The width w2 of the last inner coil CIE can be made larger than the width w1 of the intermediate inner coil CII. The width w1 of the first inner coil CI1 and the width w1 of the intermediate inner coil CII can be made substantially equal.

[0036] By winding the coil substrate 10, the motor coil substrate 20 of the embodiment is obtained. The coil substrate 10 is wound so that each portion P makes approximately one turn. An example of how to wind the coil substrate 10 will be described with reference to FIG. 1(B). When the coil substrate 10 in FIG. 4(A) is wound, the first portion P1 forms approximately one turn. The second portion P2 connected to the first portion P1 forms approximately one turn. As shown in FIG. 1(B), the first portion P1 is wound inside. The first portion P1 forms the first turn. The flexible substrate 22 forming the first portion P1 is the first flexible substrate 22-1. The second portion P2 is wound outside the first portion P1. The second portion P2 forms the second turn. The flexible substrate 22 forming the second portion P2 is the second flexible substrate 22-2.

[0037] FIG. 3(B) schematically shows a cross section of the motor coil substrate 20. In FIG. 3(B), the motor coil substrate 20 is cut along a plane parallel to the rotation direction MR of the motor 110. As shown in FIG. 3(B), the motor coil substrate 20 can be divided into equal areas. The first wiring group 51g or the second wiring group 52g is arranged in each area. Alternatively, the first wiring group 51g and the second wiring group 52g are arranged in each area. In that case, the first wiring group 51g and the second wiring group 52g of the same phase are arranged in one area. For example, the first wiring group 51g forming the U-phase coil and the second wiring group 52g forming the U-phase coil are arranged. When a plurality of wiring groups are arranged in one area, each wiring group arranged in one area forms a different coil C. The first wiring group 51g and the second wiring group 52g in one coil C are not arranged in one area. The first wiring group 51g and the second wiring group 52g in one coil C are not arranged in the same area.

[0038] In FIG. 3(B), the motor coil substrate 20 is divided into six areas. The central angle of each area is approximately 60 degrees. The area between 0 degrees and 60 degrees is the first area E1. The area between 60 degrees and 120 degrees is the second area E2. The area adjacent to the second area E2 is the third area E3. The area adjacent to the third area E3 is the fourth area E4. The area adjacent to the fourth area E4 is the fifth area E5. The area adjacent to the fifth area E5 is the sixth area E6. In the first area E1, the first wiring group 51g of the first coil C1, the second wiring group 52g of the fourth coil C4, and the first wiring group 51g of the seventh coil C7 are arranged. In the second area E2, the first wiring group 51g of the second coil C2, the second wiring group 52g of the fifth coil C5, and the first wiring group 51g of the eighth coil C8 are arranged. In the third area E3, the first wiring group 51g of the third coil C3, the second wiring group 52g of the sixth coil C6, and the first wiring group 51g of the ninth coil C9 are arranged. In the fourth area E4, the second wiring group 52g of the first coil C1, the first wiring group 51g of the fourth coil C4, and the second wiring group 52g of the seventh coil C7 are arranged. In the fifth area E5, the second wiring group 52g of the second coil C2, the first wiring group 51g of the fifth coil C5, and the second wiring group 52g of the eighth coil C8 are arranged. In the sixth area E6, the second wiring group 52g of the third coil C3, the first wiring group 51g of the sixth coil C6, and the second wiring group 52g of the ninth coil C9 are arranged.

[0039] A substrate having a first-round substrate and a second-round substrate and a circle r having a radius R are prepared. Coils are formed on the first-round substrate. Coils are formed on the second-round substrate. The length of the first-round substrate and the length of the second-round substrate are 2πR. The first-round substrate extends from the start portion to the end portion. The second-round substrate extends from the start portion to the end portion. The end portion of the first-round substrate and the start portion of the second-round substrate coincide. The substrate is wound such that the second-round substrate is wound around the first-round substrate. At this time, the substrate is wound such that the first-round substrate is located on the circumference of the circle r. Then, the second-round substrate is wound around the first-round substrate. Therefore, the second-round substrate is not located on the circumference of the circle r. The second-round substrate is located outside the circumference of the circle r. Therefore, the start portion of the second-round substrate is not located directly above the start portion of the first-round substrate. Therefore, it is difficult to align the positions of the coils on the first-round substrate and the coils on the second-round substrate.

[0040] According to the coil substrate 10 of the embodiment, the width of the last inner coil CIE (second width w2) is larger than the width of the first inner coil CI1 (first width w1). Thereby, the length of the first flexible substrate 22-1 is adjusted. Therefore, even if the second flexible substrate 22-2 is wound around the first flexible substrate 22-1 as in Patent Document 1, the positions of the first inner coil CI1 and the first outer coil CO1 can be aligned with high accuracy. The positions of the intermediate inner coil CII and the intermediate outer coil COI can be aligned with high accuracy. The positions of the last inner coil CIE and the last outer coil COE can be aligned with high accuracy. A motor coil substrate 20 having a high occupation ratio can be obtained.

[0041] The motor coil substrate 20 of the embodiment is cut along a plane including the rotation direction MR of the motor. For example, the motor coil substrate 20 is cylindrical. An example of the shape of the cross section obtained by cutting is shown in FIG. 3(A). The shape shown in FIG. 3(A) is substantially circular. A virtual circle G is drawn in FIG. 3(A). The virtual circle G has a radius r and a circumference G1. As shown in FIG. 4(B), the upper surface of the first surface wiring wf of the first flexible substrate 22-1 is located on the circumference G1. The coil substrate forming the motor coil substrate 20 has a thickness t. As shown in FIG. 2(A), the thickness t is the sum of the thickness of the first flexible substrate 22-1, the thickness of the first surface wiring wf on the first flexible substrate 22-1, and the thickness of the second surface wiring ws on the first flexible substrate 22-1. An intersection point PO between the extension line of one end 22L and the circumference G1 is shown in FIG. 3(A). An intersection point P2 between the extension line of one end 22L and the extension line of the upper surface of the second surface wiring ws on the first flexible substrate 22-1 is shown in FIG. 3(A). A straight line CL that contacts the virtual circle G passing through the intersection point P2 is shown in FIG. 3(A). As shown in FIG. 3(A), the straight line CL and the virtual circle G are in contact at point P. The center BT of the virtual circle G is shown in FIG. 3(A). An angle θ between a straight line 1 passing through the intersection point P0 and the center BT and a straight line 2 passing through the point P and the center BT is shown in FIG. 3. The difference δ between the second width w2 and the first width w1 satisfies a relational expression 1 including the radius r, the thickness t, and the angle θ. The angle θ satisfies a relational expression 2. Relational Expression 1: δ = (r + t)sinθ - 2πrθ / 360 Relational Expression 2: θ = cos -1 (r / (r + t)) When the difference δ between the second width w2 and the first width w1 satisfies Relational Expression 1, the positions of the inner coil CI and the outer coil CO can be aligned with high precision. The width w3 of the first wiring group of the first inner coil CII is equal to the width w7 of the first wiring group of the last inner coil CIE. Further, the width w8 of the second wiring group of the last inner coil CIE is larger than the width w4 of the second wiring group of the first inner coil CI1. In this case, the difference δ between the width w8 of the second wiring group of the last inner coil CIE and the width w4 of the second wiring group of the first inner coil CI1 satisfies Relational Expression 1. An insulating film can be formed on the first surface F of the flexible substrate 22 and on the wiring wf on the first surface. An insulating film can be formed on the second surface S of the flexible substrate 22 and on the wiring ws on the second surface. When the insulating film is formed, the coil substrate 10 includes the insulating film. When the coil substrate 10 includes the insulating film, the thickness t includes the thickness of the insulating film.

[0042] Regarding the width W of the coil C, the inner coil CI and the outer coil CO have a similar relationship. The width of the first outer coil CO1 and the width of the intermediate outer coil COI are approximately equal. The width of the last outer coil COE is larger than the width of the first outer coil CO1. The width of the last outer coil COE is adjusted by the width of the second wiring 52 of the last outer coil COE. In the last outer coil COE, the width of the second wiring 52 is larger than the width of the first wiring 51. The width of the last outer coil COE is adjusted by the width of the second wiring group 52g of the last outer coil COE. In the outer coil COE, the width of the second wiring group 52g is larger than the width of the first wiring group 51g. Thus, the width W of the coil C is adjusted for the inner coil CI and the outer coil CE in a similar manner.

Explanation of Reference Numerals

[0043] 10 Coil substrate 20 Coil substrate for motor 22 Flexible substrate 22 - 1 First flexible substrate 22 - 2 Second flexible substrate 48 Magnet C Coil

Claims

A coil substrate for a motor manufactured by winding a flexible substrate including a first flexible substrate having one end and a second flexible substrate extending from the first flexible substrate, and a plurality of coils formed on the flexible substrate. The plurality of coils are arranged substantially in a line, wherein the plurality of coils include an m-th coil, an (m + 1)-th coil, an (m + 2)-th coil, an (m + 3)-th coil, and an (m + 4)-th coil. The (m + 1)-th coil is positioned next to the m-th coil, the (m + 2)-th coil is positioned next to the (m + 1)-th coil, the (m + 3)-th coil is positioned next to the (m + 2)-th coil, and the (m + 4)-th coil is positioned next to the (m + 3)-th coil. The m-th coil, the (m + 1)-th coil, and the (m + 2)-th coil partially overlap, and the m-th coil and the (m + 4)-th coil do not overlap. Here, m is a natural number. The second flexible substrate is wound around the first flexible substrate. The first flexible substrate forms the first turn, and the second flexible substrate forms the second turn. The coils on the first flexible substrate are inner coils, and the coils on the second flexible substrate are outer coils. The number of the inner coils (the first number) and the number of the outer coils (the second number) are plural and the same. The inner coils have a first inner coil closest to the one end and a last inner coil closest to the second flexible substrate. Each of the coils has a width. The width of the last inner coil is a second width, and the width of the first inner coil is a first width. The second width is larger than the first width. m is a natural number. The second flexible substrate is wound around the first flexible substrate. The first flexible substrate forms the first turn, and the second flexible substrate forms the second turn. The coils on the first flexible substrate are inner coils, and the coils on the second flexible substrate are outer coils. The number of the inner coils (the first number) and the number of the outer coils (the second number) are plural and the same. The inner coils have a first inner coil closest to the one end and a last inner coil closest to the second flexible substrate. Each of the coils has a width. The width of the last inner coil is a second width, and the width of the first inner coil is a first width. The second width is larger than the first width. Claim 2 The coil substrate for a motor according to claim 1, wherein the flexible substrate has a short side and a long side, the coils are arranged along the long side, and the width is measured along the long side. Claim 3 The motor coil substrate according to claim 1, wherein when the motor coil substrate is disposed around a magnet, a motor is formed by the magnet and the motor coil substrate, two straight lines (a first straight line and a second straight line) perpendicular to the rotation direction of the motor are prepared, and when the last inner coil is sandwiched between the first straight line and the second straight line, the distance between the first straight line and the second straight line is the second width, and when the first inner coil is sandwiched between the first straight line and the second straight line, the distance between the first straight line and the second straight line is the first width.

4. The motor coil substrate according to claim 1, wherein the inner coil includes an intermediate inner coil between the first inner coil and the last inner coil, and the width of the intermediate inner coil is substantially equal to the first width.

5. The motor coil substrate according to claim 1, wherein each of the coils is formed by a central space and wiring formed around the central space, the number of turns of the coil is plural, the wiring includes a plurality of first wirings and a plurality of second wirings, the first wiring and the second wiring face each other through the central space, each of the first wirings is substantially parallel to each other, each of the second wirings is substantially parallel to each other, the first wiring and the second wiring are substantially parallel, all of the first wirings form a first wiring group, all of the second wirings form a second wiring group, the first wiring group has a width of the first wiring group, the second wiring group has a width of the second wiring group, in the first inner coil, the width of the first wiring group and the width of the second wiring group are substantially equal, and in the last inner coil, the width of the first wiring group and the width of the second wiring group are different.

6. The motor coil substrate according to claim 5, wherein in the last inner coil, the width of the second wiring group is larger than the width of the first wiring group.

7. The motor coil substrate according to claim 5, wherein the inner coil includes an intermediate inner coil between the first inner coil and the last inner coil, and in the intermediate inner coil, the width of the first wiring group and the width of the second wiring group are substantially equal.

8. The motor coil substrate according to claim 5, wherein the inner coil is completely disposed within the first flexible substrate, and the outer coil is completely disposed within the second flexible substrate.

9. The motor coil substrate according to claim 5, wherein when the motor coil substrate is disposed around the magnet, a motor is formed by the magnet and the motor coil substrate, and the angle between the rotation direction of the motor and the first wiring is approximately 90 degrees.

10. The motor coil substrate according to claim 9, wherein the flexible substrate has a first surface and a second surface opposite to the first surface, and the wiring forming the coil includes a first surface wiring formed on the first surface and a second surface wiring formed on the second surface. When the coil substrate is wound, the first surface faces the magnet, a cross-section obtained by cutting the motor coil substrate with a plane parallel to the rotation direction of the motor and a virtual circle are prepared, and the virtual circle and the motor coil substrate are arranged such that most of the upper surface of the first surface wiring formed on the first flexible substrate overlaps the circumference of the virtual circle, and the difference (δ) between the second width and the first width satisfies the following relational expression 1. Relational expression 1: δ = (r + t) sinθ - 2πrθ / 360 Relational Expression 2: θ = cos -1 (r / (r + t)) In the relational expression 1, r is the radius of the virtual circle, t in the relational expression 1 is the sum of the thickness of the flexible substrate, the thickness of the first surface wiring, and the thickness of the second surface wiring, and θ in the relational expression 1 is obtained from the relational expression 2.

11. The motor coil substrate according to claim 10, further including the first flexible substrate and an insulating film formed on the inner coil, and the thickness t further includes the thickness of the insulating film.

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