Print circuit board

Abstract

To provide a print circuit board capable of suppressing outflow of an adhesive agent from between two print circuit boards adjacent to each other in a thickness direction when the two print circuit boards are bonded to each other.SOLUTION: A print circuit board includes a base film having a main surface, and a first wiring and a second wiring disposed on a main surface. Each of the first wiring and the second wiring is spirally wound in plan view. The second wiring is disposed inside the first wiring in plan view. A pitch between the two portions of the adjacent first wiring and a pitch between the two portions of the adjacent second wiring are smaller than an interval between the portion of an outermost circumference of the first wiring and the portion of an innermost circumference of the second wiring. A value obtained by dividing the number of turns of the first wiring by the number of turns of the second wiring is 0.1 or more and 10.0 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to printed wiring boards. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2021-197409 (Patent Document 1) describes a coil device. The coil device described in Patent Document 1 has a plurality of printed wiring boards. The printed wiring boards have a base film and wiring. The base film has a main surface. The wiring is arranged on the main surface. The wiring is wound in a spiral shape in a plan view.

[0003] In the coil device described in Patent Document 1, a plurality of printed wiring boards are stacked along the thickness direction of the coil device, and two adjacent printed wiring boards are bonded to each other with an adhesive. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-197409 Summary of the Invention [Problem to be solved by the invention]

[0005] In the coil device described in Patent Document 1, when two adjacent printed wiring boards are bonded together, the adhesive may leak out from between the two printed wiring boards, causing poor bonding.

[0006] The present disclosure has been made in consideration of the above-described problems of the conventional art. More specifically, the present disclosure provides a printed wiring board that can prevent adhesive from leaking out from between two printed wiring boards that are adjacent in the thickness direction when the two printed wiring boards are bonded together. [Means for solving the problem]

[0007] The printed wiring board according to the present disclosure includes a base film having a main surface, and first and second wirings arranged on the main surface. Each of the first and second wirings is spirally wound in a plan view. The second wirings are arranged more inward than the first wirings in a plan view. The pitch between two adjacent portions of the first wirings and the pitch between two adjacent portions of the second wirings are smaller than the distance between the innermost portion of the first wirings and the outermost portion of the second wirings. The value obtained by dividing the number of turns of the first wiring by the number of turns of the second wirings is 0.1 or more and 10.0 or less. [Effects of the Invention]

[0008] According to the printed wiring board according to the present disclosure, when two printed wiring boards adjacent to each other in the thickness direction are bonded together, it is possible to prevent adhesive from leaking out from between the two printed wiring boards. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view of a printed wiring board 100. FIG. [Figure 2] FIG. 2 is a bottom view of printed wiring board 100. FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view of two printed wiring boards 100 arranged one on top of the other. [Figure 5] FIG. 5 is a plan view of a printed wiring board 100 according to the first modification. [Figure 6] FIG. 6 is a bottom view of printed wiring board 100 according to the first modification. [Figure 7] FIG. 7 is a plan view of a printed wiring board according to the second modification. [Figure 8] FIG. 8 is a manufacturing process diagram of the printed wiring board 100. [Figure 9] FIG. 9 is a cross-sectional view illustrating the preparation step S1. [Figure 10] FIG. 10 is a cross-sectional view illustrating the through-hole forming step S2. [Figure 11] FIG. 11 is a cross-sectional view illustrating the electroless plating step S3. [Figure 12] FIG. 12 is a cross-sectional view illustrating the resist pattern forming step S4. [Figure 13] FIG. 13 is a cross-sectional view illustrating the electrolytic plating step S5. [Figure 14] FIG. 14 is a cross-sectional view illustrating the resist pattern removing step S6. [Figure 15] FIG. 15 is a plan view of the printed wiring board 200. As shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described.

[0011] (1) A printed wiring board according to an embodiment includes a base film having a main surface, and first and second wirings disposed on the main surface. Each of the first and second wirings is spirally wound in a plan view. The second wirings are disposed more inward than the first wirings in a plan view. The pitch between two adjacent portions of the first wirings and the pitch between two adjacent portions of the second wirings are smaller than the distance between the innermost portion of the first wirings and the outermost portion of the second wirings. The value obtained by dividing the number of turns of the first wiring by the number of turns of the second wirings is 0.1 or more and 10.0 or less. The printed wiring board according to (1) above can prevent adhesive from leaking out from between two printed wiring boards that are adjacent in the thickness direction when the two printed wiring boards are bonded together.

[0012] (2) In the printed wiring board of (1) above, the value obtained by dividing the number of turns of the first wiring by the number of turns of the second wiring may be equal to or greater than 0.1 and less than 2.0. The printed wiring board of (2) above makes it possible to maintain the thrust of the coil.

[0013] (3) In the printed wiring board of (1) above, the value obtained by dividing the number of turns of the first wiring by the number of turns of the second wiring may be 0.2 or more and 10.0 or less. The printed wiring board of (3) above can improve correction performance when magnet misalignment occurs.

[0014] (4) In the printed wiring board of (1) above, the value obtained by dividing the number of turns of the first wiring by the number of turns of the second wiring may be equal to or greater than 0.2 and less than 2.0. The printed wiring board of (4) above can improve the correction performance when magnet misalignment occurs while maintaining the thrust of the coil, and can particularly suppress the outflow of adhesive.

[0015] [Details of the embodiments of the present disclosure] Next, details of an embodiment of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and redundant description will not be repeated. A printed wiring board according to the embodiment is referred to as a printed wiring board 100.

[0016] (Configuration of printed wiring board 100) The configuration of the printed wiring board 100 will be described below.

[0017] FIG. 1 is a plan view of printed wiring board 100. FIG. 2 is a bottom view of printed wiring board 100. FIG. 2 shows printed wiring board 100 as viewed from the opposite side to that of FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1. As shown in FIGS. 1 to 3, printed wiring board 100 has a base film 10, a first wiring 21, a second wiring 22, a third wiring 23, and a fourth wiring 30.

[0018] The base film 10 has a first main surface 10a and a second main surface 10b. The first main surface 10a and the second main surface 10b are end surfaces of the base film 10 in the thickness direction. The second main surface 10b is the surface opposite to the first main surface 10a. The base film 10 is made of a flexible, electrically insulating material. The base film 10 is made of, for example, polyimide, fluororesin, liquid crystal polymer, etc. The base film 10 may also be made of other materials.

[0019] The first wiring 21, the second wiring 22, and the third wiring 23 are arranged on the first main surface 10a. The first wiring 21 and the second wiring 22 are wound in a spiral shape in a plan view. The second wiring 22 is located more inward than the first wiring 21 in a plan view. It is preferable that the first wiring 21 is located more outward than the midpoint between the outermost periphery of the first wiring 21 and the innermost periphery of the second wiring 22 in a plan view.

[0020] The pitch between adjacent first wirings 21 is defined as pitch P1. The pitch between adjacent second wirings 22 is defined as pitch P2. The distance between the innermost portion of the first wiring 21 and the outermost portion of the second wiring 22 is defined as interval SP. Pitch P1 and pitch P2 are smaller than interval SP. Pitch P1 is, for example, equal to pitch P2. Pitch P1 may be different from pitch P2. A terminal that is electrically independent from the first wiring 21 and second wiring 22 may be disposed between the innermost portion of the first wiring 21 and the outermost portion of the second wiring 22.

[0021] The first wiring 21 has a land 21a at one end. The land 21a is located on the outermost periphery of the first wiring 21. The second wiring 22 has a land 22a at one end. The land 22a is located on the innermost periphery of the second wiring 22. The other end of the first wiring 21 and the other end of the second wiring 22 are connected by a third wiring 23.

[0022] The value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 is 0.1 or more and 10.0 or less. The value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 is preferably 0.1 or more and less than 2.0, or 0.2 or more and 10.0 or less. The value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 is more preferably 0.2 or more and less than 2.0.

[0023] In addition, when the first wiring 21 (second wiring 22) is wound more than n turns (n ​​is a natural number) but does not reach (n+1) turns, the first wiring 21 (second wiring 22) is deemed to be wound (n+1) turns.

[0024] The fourth wiring 30 is disposed on the second main surface 10b. The fourth wiring 30 is wound in a spiral shape in a plan view. The fourth wiring 30 has a land 30a at one end and a land 30b at the other end. The lands 30a and 30b are located at the innermost and outermost peripheries of the fourth wiring 30, respectively. The land 30a overlaps with the land 22a in a plan view.

[0025] The first wiring 21, the second wiring 22, the third wiring 23, and the fourth wiring 30 each have, for example, a seed layer 41, an electroless plating layer 42, and an electrolytic plating layer 43.

[0026] The seed layer 41 is disposed on the main surfaces (first main surface 10a and second main surface 10b) of the base film 10. The seed layer 41 is a layer of a nickel (Ni)-chromium (Cr) alloy formed by, for example, sputtering. The seed layer 41 may also be a sintered layer formed by sintering conductive particles such as copper (Cu) particles.

[0027] The electroless plated layer 42 is disposed on the seed layer 41. The electroless plated layer 42 is a layer formed by electroless plating. The electroless plated layer 42 is formed of, for example, copper. The electrolytic plated layer 43 is a layer formed by electrolytic plating. The electrolytic plated layer 43 is formed of, for example, copper.

[0028] A through hole 10c is formed in the base film 10. The through hole 10c penetrates the base film 10 in the thickness direction. In plan view, the through hole 10c overlaps with the land 22a and the land 30a. A through hole 41a is formed in the seed layer 41. The inner wall surface of the through hole 41a is continuous with the inner wall surface of the through hole 10c.

[0029] Electroless plating layer 42 is also disposed on the inner wall surfaces of through holes 10c and 41a. Second wiring 22 and fourth wiring 30 are electrically connected to each other by electroless plating layer 42 disposed on the inner wall surfaces of through holes 10c and 41a and electrolytic plating layer 43 disposed on electroless plating layer 42.

[0030] When a voltage is applied between the land 21a and the land 30b, a current flows in a spiral shape through the first wiring 21, the second wiring 22, and the fourth wiring 30, generating a magnetic field. From another perspective, the first wiring 21, the second wiring 22, and the fourth wiring 30 form a coil.

[0031] A plurality of printed wiring boards 100 are used in a stacked manner. Fig. 4 is a cross-sectional view showing two printed wiring boards 100 arranged in a stacked manner. As shown in Fig. 4, the two printed wiring boards 100 are designated as printed wiring board 100A and printed wiring board 100B, respectively. Printed wiring board 100A and printed wiring board 100B are arranged such that, for example, a first main surface 10a of printed wiring board 100A faces a first main surface 10a of printed wiring board 100B.

[0032] An adhesive 50 is disposed between printed wiring board 100A and printed wiring board 100B. This bonds printed wiring board 100A and printed wiring board 100B to each other. Although not shown, first wiring 21 of printed wiring board 100A and first wiring 21 of printed wiring board 100B are electrically connected, whereby the coil of printed wiring board 100A and the coil of printed wiring board 100B are electrically connected and function as a single coil.

[0033] In this example, two printed wiring boards 100 are arranged one on top of the other, but the number of printed wiring boards 100 arranged one on top of the other may be three or more.

[0034] <Variation 1> Fig. 5 is a plan view of printed wiring board 100 according to Modification 1. Fig. 6 is a bottom view of printed wiring board 100 according to Modification 1. Fig. 6 shows printed wiring board 100 according to Modification 1 as seen from the opposite side to that of Fig. 5. As shown in Figs. 5 and 6, printed wiring board 100 does not have to have third wiring 23.

[0035] The first wiring 21 may have a land 21b at the other end, and the second wiring 22 may have a land 22b at the other end. The lands 21b and 22b form terminal portions.

[0036] The lands 21a and 30b may overlap in a plan view. The lands 22a and 30a may overlap in a plan view. The base film 10 may have a through hole 10d (not shown) and a through hole 10e (not shown) formed therein, penetrating the base film 10 in the thickness direction. The through hole 10d overlaps the lands 21a and 30b in a plan view. The through hole 10e overlaps the lands 22a and 30a in a plan view. Although not shown, an electroless plated layer 42 and an electrolytic plated layer 43 are disposed on the inner wall surface of the through hole 10d, and an electroless plated layer 42 and an electrolytic plated layer 43 are disposed on the inner wall surface of the through hole 10e. As a result, the first wiring 21 is electrically connected to the second wiring 22 via the fourth wiring 30. In printed wiring board 100, a configuration other than the wiring constituting the coil may be disposed between the innermost periphery of first wiring 21 and the outermost periphery of second wiring 22.

[0037] <Variation 2> FIG. 7 is a plan view of a printed wiring board according to Modification 2. As shown in FIG. 7, the innermost portion of the first wiring 21 may be partially connected continuously to the outermost portion of the second wiring 22. In this case, the distance between the innermost portion of the first wiring 21 that does not constitute the outermost portion of the second wiring 22 and the outermost portion of the second wiring 22 that does not constitute the innermost portion of the first wiring 21 is the distance SP. In this case, the outermost portion of the second wiring 22 that does not constitute the innermost portion of the first wiring 21 is located more inward than the innermost portion of the first wiring 21 that does not constitute the outermost portion of the second wiring 22. Therefore, the second wiring 22 is located more inward than the first wiring 21. In the second modification, the innermost periphery of the first wiring 21 is a range starting from a point (point P in FIG. 7) closest to the land 21a where the pitch P1 with the adjacent wiring on the inside is greater than in other parts, going around inward from there, and ending at a point (point P' in FIG. 7) closest to point P again. Similarly, the outermost periphery of the second wiring 22 is a range starting from a point (point Q in FIG. 7) closest to the land 22a where the pitch P2 with the adjacent wiring on the outside is greater than in other parts, going around inward from there, and ending at a point (point Q' in FIG. 7) closest to point Q again.

[0038] The spiral shape formed by the first wiring 21 and the spiral shape formed by the second wiring 22 may be the same shape or different shapes in a plan view. When the spiral shape formed by the first wiring 21 and the spiral shape formed by the second wiring 22 are different, the interval SP becomes smaller in parts. This embodiment also includes an embodiment in which the interval SP is partially smaller as long as the pitch between two adjacent portions of the first wiring 21 and the pitch between two adjacent portions of the second wiring 22 have parts where they are smaller than the maximum value of the interval SP between the innermost portion of the first wiring 21 (or the innermost portion of the first wiring 21 that does not constitute the outermost portion of the second wiring 22) and the outermost portion of the second wiring 22 (or the outermost portion of the second wiring 22 that does not constitute the innermost portion of the first wiring 21). The spacing SP in the portion where the spacing SP is partially smaller may be smaller than or the same as the pitch between two adjacent portions of the first wiring 21 and the pitch between two adjacent portions of the second wiring 22. The second wiring 22 may be present so as to divide into multiple parts the region between the innermost portion of the first wiring 21 that does not constitute the outermost portion of the second wiring 22 and the outermost portion of the second wiring 22 that does not constitute the innermost portion of the first wiring 21. In this case, the spacing SP is the maximum value of the spacing SP in the multiple regions.

[0039] In the second modification, when the first wiring 21 (second wiring 22) is wound more than n turns (n ​​is a natural number) but does not reach (n+1) turns, the first wiring 21 (second wiring 22) is considered to be wound (n+1) turns. In the second modification, the first wiring 21 is the portion from the land 21a to the point P', and the second wiring 22 is the portion from the land 22a to the point Q'.

[0040] (Method of manufacturing printed wiring board 100) A method for manufacturing the printed wiring board 100 will be described below.

[0041] Fig. 8 is a manufacturing process diagram of printed wiring board 100. As shown in Fig. 8, the manufacturing process of printed wiring board 100 includes a preparation step S1, a through-hole forming step S2, an electroless plating step S3, a resist pattern forming step S4, an electrolytic plating step S5, a resist pattern removing step S6, and an etching step S7.

[0042] FIG. 9 is a cross-sectional view illustrating the preparation step S1. As shown in FIG. 9, in the preparation step S1, a base film 10 is prepared. The base film 10 prepared in the preparation step S1 has a seed layer 41 disposed on a first main surface 10a and a second main surface 10b. FIG. 10 is a cross-sectional view illustrating the through hole forming step S2. In the through hole forming step S2, as shown in FIG. 10, through holes 10c and through holes 41a are formed. The through holes 10c and through holes 41a are formed, for example, by irradiating a laser.

[0043] 11 is a cross-sectional view illustrating the electroless plating step S3. As shown in FIG. 11, in the electroless plating step S3, electroless plating is performed to form an electroless plated layer 42 on the seed layer 41, the inner wall surfaces of the through holes 41a, and the inner wall surfaces of the through holes 10c.

[0044] 12 is a cross-sectional view illustrating the resist pattern forming step S4. As shown in FIG. 12, in the resist pattern forming step S4, a resist pattern 60 is formed on the electroless plated layer 42. The resist pattern 60 has openings 61. The electroless plated layer 42 is exposed through the openings 61. The resist pattern 60 is formed, for example, by applying a dry film resist and patterning the dry film resist by exposing and developing it.

[0045] 13 is a cross-sectional view illustrating the electrolytic plating step S5. As shown in FIG. 13, in the electrolytic plating step S5, an electric current is passed through the seed layer 41 and the electroless plated layer 42 to perform electrolytic plating, thereby forming the electrolytic plated layer 43 on the electroless plated layer 42 exposed from the opening 61.

[0046] 14 is a cross-sectional view illustrating resist pattern removal step S6. As shown in FIG. 14, resist pattern 60 is removed in resist pattern removal step S6. In etching step S7, electroless plated layer 42 and seed layer 41 between adjacent electrolytic plated layers 43 (i.e., electroless plated layer 42 and seed layer 41 that were under resist pattern 60) are removed by etching. In this manner, printed wiring board 100 having the structure shown in FIGS. 1 to 4 is manufactured.

[0047] (Effects of the printed wiring board 100) The effects of printed wiring board 100 will be described below in comparison with a printed wiring board according to a comparative example.

[0048] FIG. 15 is a plan view of printed wiring board 200. As shown in FIG. 15, printed wiring board 200 has fifth wiring 24 instead of first wiring 21, second wiring 22, and third wiring 23. Fifth wiring 24 is wound in a spiral shape in plan view. Fifth wiring 24 is wiring that forms a coil. In this respect, the configuration of printed wiring board 200 differs from the configuration of printed wiring board 100. That is, the configuration of printed wiring board 200 differs from the configuration of printed wiring board 100 in that the wiring that forms the coil arranged on first main surface 10a is not divided into an inner side and an outer side in plan view.

[0049] As described above, in the printed wiring board 200, no wiring that constitutes another coil is arranged outside the wiring that constitutes the coil in a plan view (i.e., the fifth wiring 24). Therefore, when two printed wiring boards 200 are bonded together with the adhesive 50, the adhesive 50 may leak out from between the two printed wiring boards 200.

[0050] On the other hand, in printed wiring board 100, wiring that configures one coil (i.e., first wiring 21) is arranged outside wiring that configures another coil (i.e., second wiring 22) in a plan view. Therefore, when two printed wiring boards 100 are bonded together with adhesive 50, the outflow of adhesive 50 is stopped by first wiring 21, making it difficult for adhesive 50 to outflow from between the two printed wiring boards 100. More specifically, when the value obtained by dividing the number of turns of first wiring 21 by the number of turns of second wiring 22 is 0.1 or more and 10.0 or less, it is possible to sufficiently prevent adhesive 50 from outflowing from between the two printed wiring boards 100.

[0051] Printed wiring board 100 may constitute an actuator together with a magnet arranged opposite first wiring 21 and second wiring 22. The more turns of first wiring 21, the easier it is to correct the position of the magnet even if the position of the magnet shifts during operation of the actuator. Therefore, when the value obtained by dividing the number of turns of first wiring 21 by the number of turns of second wiring 22 is 0.2 or more and 10.0 or less, it is possible to improve the correction performance when magnet shift occurs.

[0052] Furthermore, the greater the number of turns of second wiring 22, the greater the thrust that the coil of printed wiring board 100 generates against the magnet. Therefore, when the value obtained by dividing the number of turns of first wiring 21 by the number of turns of second wiring 22 is 0.1 or more and less than 2.0, it is possible to maintain the thrust. Furthermore, when the value obtained by dividing the number of turns of first wiring 21 by the number of turns of second wiring 22 is 0.2 or more and less than 2.0, it is possible to improve the correction performance when magnet misalignment occurs while maintaining the thrust of the coil, and it is particularly possible to suppress the outflow of adhesive 50.

[0053] <Example> Samples 1 to 11 were prepared to evaluate the relationship between the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 and the outflow properties of the adhesive 50, the correction performance when magnet misalignment occurs, and the coil thrust.

[0054] As shown in Table 1, in Samples 1 to 11, the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 was changed.

[0055] [Table 1]

[0056] The outflow of the adhesive 50 in Samples 1 to 11 was evaluated on a five-point scale from A to E. The evaluation of the outflow of the adhesive 50 decreased in order from A to E. The outflow state of the adhesive 50 was visually observed. When no adhesive 50 had flowed out from between the two printed wiring boards, it was evaluated as A. When a small amount of adhesive 50 had flowed out from between the two printed wiring boards, it was evaluated as B. When adhesive 50 had flowed out from between the two printed wiring boards in the straight portions of the first wiring 21, it was evaluated as C. When adhesive 50 had flowed out from between the two printed wiring boards in the straight portions and corners of the first wiring 21, it was evaluated as D. When a large amount of adhesive 50 had flowed out from between the two printed wiring boards, it was evaluated as E.

[0057] The correction performance of Samples 1 to 11 when magnet misalignment occurred was evaluated on a three-point scale from A to C. The evaluation of correction performance when magnet misalignment occurred decreased in order from A to B and C. If magnet misalignment could be corrected even if the magnet was misaligned outside the outer shape of the first wiring 21, it was evaluated as A. If magnet misalignment could be corrected as long as the magnet was within the inner range of the outer shape of the first wiring 21, it was evaluated as B. If magnet misalignment could not be corrected, it was evaluated as C.

[0058] The thrust of Samples 1 to 11 was evaluated on a five-point scale from A to E. The thrust of Samples 1 to 11 was calculated by simulation. The thrust evaluation was A, B, C, D, and E in decreasing order. If the thrust was 90 percent or more of Sample 1, it was evaluated as A. If the thrust was 80 percent or more but less than 90 percent of Sample 1, it was evaluated as B. If the thrust was 70 percent or more but less than 80 percent of Sample 1, it was evaluated as C. If the thrust was 60 percent or more but less than 70 percent of Sample 1, it was evaluated as D. If the thrust was less than 60 percent of Sample 1, it was evaluated as E.

[0059] Table 2 shows the evaluation results of Samples 1 to 11 with respect to the outflow of adhesive 50, the correction performance when magnet misalignment occurs, and the thrust force.

[0060] [Table 2]

[0061] In Sample 1, the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 was less than 0.1, and in Sample 11, the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 was more than 10.0. On the other hand, in Samples 2 to 10, the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 was within the range of 0.1 to 10.0.

[0062] In Samples 1 and 11, the outflow of the adhesive 50 was evaluated as E. On the other hand, in Samples 2 to 10, the outflow of the adhesive 50 was evaluated as C or higher. This comparison revealed that the outflow of the adhesive 50 can be suppressed by setting the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 to be 0.1 or more and 10.0 or less. In Samples 4 to 6, in which the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 was within the range of 0.2 or more and less than 2.0, the outflow of the adhesive 50 was evaluated as A.

[0063] Furthermore, in samples 4 to 10, in which the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 was within the range of 0.2 to 10.0, the evaluation of correction performance when magnet misalignment occurs was A. This demonstrates that correction performance when magnet misalignment occurs can be improved by setting the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 to be within the range of 0.2 to 10.0.

[0064] Furthermore, in Samples 2 to 6, in which the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 was within the range of 0.1 or more and less than 2.0, the thrust was evaluated as B or higher. This demonstrates that it is possible to maintain thrust by setting the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 to be 0.1 or more and less than 2.0. Combining these results, it is clear that when the value obtained by dividing the number of turns of the first wiring 21 by the number of turns of the second wiring 22 is within the range of 0.2 or more and less than 2.0, it is possible to improve correction performance when magnet misalignment occurs while maintaining coil thrust, and outflow of adhesive 50 is particularly suppressed.

[0065] The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims rather than the above embodiments, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0066] 10 Base film 10a First principal surface 10b Second principal surface 10c, 10d, 10e through holes 21 1st wiring 21a, 21b Land 22 2nd wiring 22a, 22b Land 23 3rd wiring 24 5th wiring 30 4th wiring 30a, 30b Land 41 Seed Layer 41a through hole 42 Electroless plating layer 43 Electroplated layer 50 Adhesive 60 Resist Pattern 61 Opening 100, 100A, 100B, 200 printed wiring board P1, P2 pitch S1 Preparation process S2 Through hole formation process S3 Electroless plating process S4 Resist pattern formation process S5 Electrolytic plating process S6 Resist pattern removal process S7 Etching process SP interval

Claims

1. a base film having a major surface; a first wiring and a second wiring disposed on the main surface; each of the first wiring and the second wiring is wound in a spiral shape in a plan view; the second wiring is disposed inside the first wiring in a plan view, a pitch between two adjacent portions of the first wiring and a pitch between two adjacent portions of the second wiring are smaller than a distance between an innermost portion of the first wiring and an outermost portion of the second wiring; A printed wiring board, wherein a value obtained by dividing the number of turns of the first wiring by the number of turns of the second wiring is 0.1 or more and 10.0 or less.

2. The printed wiring board according to claim 1 , wherein a value obtained by dividing the number of turns of the first wiring by the number of turns of the second wiring is equal to or greater than 0.1 and less than 2.

0.

3. The printed wiring board according to claim 1 , wherein a value obtained by dividing the number of turns of the first wiring by the number of turns of the second wiring is equal to or greater than 0.2 and equal to or less than 10.

0.

4. The printed wiring board according to claim 1 , wherein a value obtained by dividing the number of turns of the first wiring by the number of turns of the second wiring is equal to or greater than 0.2 and less than 2.0.

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