Spring member, camera module, and electronic apparatus

Abstract

This spring member includes a first surface and a second surface opposite to the first surface, and includes three or more thin wires in a cross section orthogonal to the first surface. Among the thin wires, the thin wires positioned at both ends are outer thin wires, and the thin wire between the outer thin wires is an inner thin wire. The inner thin wire has a width of 10 μm or more at the first surface and the second surface. At the first surface and the second surface, the outer thin wires have a width that is greater than the width of the inner thin wire by 2 μm to 8 μm.

Description

Spring member, camera module, and electronic device

[0001] The present disclosure relates to a spring member for a camera module, a camera module, and an electronic device.

[0002] Camera modules included in camera-equipped electronic devices such as tablet terminals and smartphones are equipped with drive mechanisms that enable autofocus and zoom. Known drive mechanisms include a lens drive system and a sensor drive system. A lens drive system drive mechanism includes a spring member that enables the lens position to be changed in the direction of the lens's optical axis. In contrast, a sensor drive system drive mechanism includes a spring member that enables the image sensor position to be changed in the direction of the lens's optical axis (see, for example, Patent Documents 1 and 2).

[0003] JP 2014-059345 A JP 2020-170170 A

[0004] The spring member includes a first spring member having a spring portion having a folded line shape when viewed from a viewpoint opposite to the plane in which the spring member extends, and a second spring member having a spring portion composed of a plurality of springs independent of each other. The spring portion connects the inner frame portion to the outer frame portion.

[0005] Whether the spring portion is provided in the first spring member or the second spring member, the spring portion is composed of a plurality of fine wires arranged at intervals in a plane perpendicular to the plane in which the spring member extends and perpendicular to the direction in which the spring portion extends. The plurality of fine wires includes a pair of outer fine wires located at the ends in the direction in which the fine wires are arranged and an inner fine wire located between the outer fine wires. From the perspective of miniaturizing the spring portion, a narrow spacing between the fine wires is required. On the other hand, to enable the spring portion to be driven, a certain spacing is required between the spring portion and the outer frame portion and between the spring portion and the inner frame portion.

[0006] The spring member is formed by wet etching of a metal foil. The resist mask used in the wet etching of the metal foil has openings corresponding to the gaps between the fine wires and openings corresponding to the gaps between the spring portion and each frame portion. The openings corresponding to the gaps between the spring portion and each frame portion have a wider opening width than the openings corresponding to the gaps between the fine wires. Therefore, the etching liquid is less likely to be supplied to the openings corresponding to the gaps between the fine wires, while the etching liquid is more likely to be supplied to the openings corresponding to the gaps between the spring portion and each frame portion.

[0007] Therefore, of the pair of side surfaces of the outer thin wire that face each other in the direction in which the thin wires are arranged, the side surface farther from the inner thin wire is more likely to have a shape with a larger hollow near the center in the thickness direction of the spring member than the side surface of the inner thin wire. As a result, during wet etching of the metal foil, a localized penetration portion that penetrates between the pair of side surfaces occurs in the outer thin wire near the center in the thickness direction of the spring member, and further etching may cause the outer thin wire to break.

[0008] A spring member for a camera module that solves the above problem includes a first surface and a second surface opposite to the first surface. In a cross section perpendicular to the first surface, the spring member includes three or more thin wires, the thin wires located at both ends of the thin wires being outer thin wires, and the thin wires sandwiched between the outer thin wires being inner thin wires. The inner thin wires have a width of 10 μm or more on the first surface and the second surface. The outer thin wires have a width that is 2 μm to 8 μm thicker than the width of the inner thin wires on the first surface and the second surface.

[0009] According to the above spring member, the inner thin wire has a width of 10 μm or more on each side, and the outer thin wire has a width that is 2 μm or more wider than the inner thin wire on each side, thereby making it possible to prevent localized penetrations and breakages in the inner thin wire and outer thin wire near the center in the thickness direction during etching. Furthermore, the inner thin wire has a width of 10 μm or more on each side, and the outer thin wire has a width that is 8 μm or less wider than the inner thin wire on each side, making it possible to prevent load concentration on the inner thin wire due to actuation of the spring member. As a result, it is possible to prevent deformation of the inner thin wire due to actuation of the spring member.

[0010] In the above spring member, for each thin wire, the width at the first surface may be a first width, the width at the second surface may be a second width, and the first width and the second width may be the first or second largest width in the thickness direction of the spring member.

[0011] According to the above spring member, the rigidity of the thin wire is prevented from becoming excessively high compared to when the inside of the first width and the second width is thicker than the first width and the second width in the thickness direction of the spring member.

[0012] In the spring member, the first width and the second width of each thin wire may be 20 μm or less.

[0013] According to the above spring member, the effect of the inner thin wire being 10 μm or more on each surface and the width of the outer thin wire being 2 μm or more and 8 μm or less thicker than the width of the inner thin wire can be significantly obtained.

[0014] In the above-mentioned spring member, of a pair of side surfaces of each outer thin wire extending along the thickness direction of the spring member, the side surface that is closer to the inner thin wire is a first side surface, and the side surface opposite the first side surface is a second side surface, and the second side surface may have a V-shape recessed from the second side surface toward the first side surface.

[0015] According to the spring member, since the outer thin wire is constricted on at least one side, the stiffness of the outer thin wire is unlikely to become excessively high.

[0016] In the spring member, the aspect ratio of the thin wire may be equal to or greater than 3 and equal to or less than 20. With the spring member, it is possible to suppress the occurrence of through holes or breakage in the thin wire during etching, and to suppress deformation of the thin wire during actuation, over a wide range of aspect ratios of the thin wire.

[0017] In the above spring member, the thickness of the spring member may be 120 μm or more and 200 μm or less.

[0018] According to the above spring member, it is possible to increase the reliability of obtaining the effect of the thin wire satisfying the above-mentioned conditions.

[0019] In the above spring member, the spring member may include any one selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium-copper.

[0020] According to the above spring member, the spring member can have high hardness, and therefore the durability of the spring member can be increased.

[0021] In the above-described spring member, the spring member may comprise a base material including any one selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium copper, the base material having a first surface and a second surface located opposite the first surface, and the spring member may further comprise a copper layer on at least one of the first surface and the second surface of the base material.

[0022] According to the present disclosure, when etching the metal foil, it is possible to suppress the occurrence of localized penetrations or breakage of the thin wire near the center of the thickness direction, while also suppressing deformation of the thin wire when the spring member is driven.

[0023] FIG. 1 is a plan view showing the structure of a spring member. FIG. 2 is a cross-sectional view showing the structure along line II-II in FIG. 1. FIGS. 3A to 3C are cross-sectional views showing an example of the structure of inner thin wires. FIGS. 4A to 4C are cross-sectional views showing an example of the structure of outer thin wires. FIG. 5 is a process diagram showing one step in a method for manufacturing a spring member. FIG. 6 is a process diagram showing one step in a method for manufacturing a spring member. FIG. 7 is a process diagram showing one step in a method for manufacturing a spring member. FIG. 8 is a process diagram showing one step in a method for manufacturing a spring member. FIG. 9 is a process diagram showing one step in a method for manufacturing a spring member. FIG. 10 is a plan view schematically showing the shape of a resist mask. FIG. 11 is a table showing evaluation results of examples and comparative examples. FIG. 12 is a table showing evaluation results of examples and comparative examples. FIG. 13 is a table showing evaluation results of examples and comparative examples.

[0024] An embodiment of a spring member for a camera module, a camera module, and an electronic device will be described with reference to Figures 1 to 13. [Spring member for camera module] A spring member for a camera module will be described with reference to Figures 1 to 4. Figure 1 schematically shows the planar structure of the spring member as seen from a viewpoint opposite to the plane in which the spring member extends.

[0025] 1, the spring member 10 for a camera module includes a first surface 10S1 and a second surface 10S2 opposite the first surface 10S1. The first surface 10S1 and the second surface 10S2 are a pair of surfaces that face each other in the thickness direction of the spring member 10. The spring member 10 includes an outer frame portion 11, an inner frame portion 12, and a spring portion 13. The spring portion 13 is a leaf spring.

[0026] The spring portion 13 includes a plurality of thin wires 13A. When viewed from a viewpoint opposite to the plane in which the spring member 10 extends, each thin wire 13A has a straight line extending along the plane in which the spring member 10 extends. Each thin wire 13A is part of the metal foil that forms the spring member 10, and adjacent thin wires 13A are connected to each other by bent portions.

[0027] In the example shown in Fig. 1, the outer frame portion 11 has an octagonal outer shape, and the inner frame portion 12 has a circular outer shape. The spring portion 13 has a folded line shape. The outer shapes of the outer frame portion 11 and the inner frame portion 12 may be changed depending on the shapes of other members included in the drive mechanism of the camera module in which the spring member 10 is mounted, i.e., members other than the spring member 10. The inner frame portion 12 is located within an area defined by the outer frame portion 11. The spring portion 13 connects the inner frame portion 12 to the outer frame portion 11.

[0028] In a lens-driving type drive mechanism, a pair of spring members 10 are arranged to sandwich the lens in the optical axis direction of the lens. In the optical axis direction, the position of the inner frame portion 12 connected to each outer frame portion 11 changes relative to that outer frame portion 11, thereby changing the position of the lens in the optical axis direction. This makes it possible for the lens-driving type drive mechanism to correct camera shake.

[0029] In contrast, in a sensor-driven drive mechanism, a pair of spring members 10 are arranged to sandwich the image sensor in the optical axis direction of the lens. The position of the inner frame portion 12 connected to each outer frame portion 11 changes relative to that outer frame portion 11 in the optical axis direction, thereby changing the position of the image sensor in the optical axis direction of the lens. This makes it possible to correct camera shake using a sensor-driven drive mechanism.

[0030] The electronic device in which the camera module including the spring member 10 is mounted may be, for example, a mobile phone terminal, a smartphone, a tablet terminal, or a notebook personal computer.

[0031] Fig. 2 shows the cross-sectional structure of the spring portion 13 taken along line II-II in Fig. 1. That is, Fig. 2 shows the cross-sectional structure of the spring member 10 taken along a plane that is perpendicular to the first surface 10S1 of the spring member 10 and perpendicular to the direction in which each thin wire 13A extends.

[0032] 2, in a cross section perpendicular to the first surface 10S1, the spring portion 13 includes three or more thin wires 13A. In this cross section, of the thin wires 13A, the thin wires 13A located at both ends in the direction in which the thin wires 13A are arranged are outer thin wires 13A1. The direction in which the thin wires 13A are arranged is the first direction D1. Of the multiple thin wires 13A, the thin wires 13A sandwiched between the outer thin wires 13A1 in the first direction D1 are inner thin wires 13A2.

[0033] 2, in a cross section perpendicular to the first surface 10S1, the spring portion 13 includes six thin wires 13A. Therefore, in the first direction D1, four inner thin wires 13A2 are sandwiched between two outer thin wires 13A1. The multiple thin wires 13A are arranged at approximately equal intervals in the first direction D1.

[0034] The width of each thin wire 13A on the first surface 10S1 is a first width WS1. The width of each thin wire 13A on the second surface 10S2 is a second width WS2. The inner thin wire 13A2 has a width of 10 μm or more on the first surface 10S1 and the second surface 10S2. The first width WS1 of the inner thin wire 13A2 is 10 μm or more, and the second width WS2 is 10 μm or more.

[0035] The outer thin wires 13A1 have a width that is 2 μm to 8 μm thicker than the width of the inner thin wires 13A2 on the first surface 10S1 and the second surface 10S2. The first width WS1 of the outer thin wires 13A1 is 2 μm to 8 μm larger than the first width WS1 of the inner thin wires 13A2. The second width WS2 of the outer thin wires 13A1 is 2 μm to 8 μm larger than the second width WS2 of the inner thin wires 13A2.

[0036] As described above, the spring member 10 of the present disclosure satisfies the following conditions 1 and 2. (Condition 1) The inner thin wire 13A2 has a width of 10 μm or more on the first surface 10S1 and the second surface 10S2. (Condition 2) The outer thin wire 13A1 has a width that is 2 μm or more and 8 μm or less thicker than the inner thin wire 13A2 on the first surface 10S1 and the second surface 10S2.

[0037] When the spring member 10 satisfies condition 1 and the lower limit of condition 2, it is possible to prevent localized penetrations and breakages near the center of the thickness direction of the inner thin wire 13A2 and the outer thin wire 13A1 during etching. Furthermore, when the spring member 10 satisfies condition 1 and the upper limit of condition 2, it is possible to prevent load concentration on the inner thin wire 13A2 due to driving of the spring member 10. As a result, it is possible to prevent deformation of the inner thin wire 13A2 due to driving of the spring member 10.

[0038] In each thin wire 13A, the first width WS1 and the second width WS2 may be the first or second largest width in the thickness direction of the spring member 10. That is, in the thickness direction of the spring member 10, the first width WS1 and the second width WS2 are equal to or larger than the widths of the thin wire 13A other than the first width WS1 and the second width WS2. In the thickness direction of the spring member 10, in each thin wire 13A, the first width WS1 and the second width WS2 are larger than the width sandwiched between the first width WS1 and the second width WS2. In this case, the rigidity of the thin wire 13A is prevented from becoming excessively high compared to when the inside of the first width WS1 and the second width WS2 in the thickness direction of the spring member 10 is thicker than the first width WS1 and the second width WS2.

[0039] The first width WS1 and the second width WS2 of each thin wire 13A may be 20 μm or less. All widths of each thin wire 13A in the thickness direction of the spring member 10 may be 20 μm or less. By setting the upper limit of the first width WS1 and the second width WS2 of each thin wire 13A to 20 μm or less, it is possible to significantly obtain the effect of the width of the thin wire 13A satisfying Conditions 1 and 2. Note that the upper limit of the first width WS1 and the second width WS2 of each thin wire 13A may be 40 μm or 15 μm.

[0040] The upper limit of each width WS1, WS2 of the inner thin wire 13A2 may be 40 μm, 20 μm, or 15 μm. When each width WS1, WS2 of the inner thin wire 13A2 is 40 μm or less, the effect of satisfying conditions 1 and 2 is more pronounced, and when each width WS1, WS2 is 20 μm or less, the effect of satisfying conditions 1 and 2 is even more pronounced.

[0041] The upper limit of each width WS1, WS2 of the outer thin wire 13A1 may be 40 μm, 20 μm, or 15 μm. When each width WS1, WS2 of the outer thin wire 13A1 is 40 μm or less, the effect of satisfying conditions 1 and 2 is further enhanced, and when each width WS1, WS2 is 20 μm or less, the effect of satisfying conditions 1 and 2 is further enhanced.

[0042] The thickness of the spring member 10 may be 120 μm or more and 200 μm or less. The thickness of the spring member 10 is the distance between the first surface 10S1 and the second surface 10S2. When the thickness of the spring member 10 falls within the above range, it is possible to increase the certainty of obtaining the effects resulting from the thin wire 13A satisfying the above-mentioned conditions 1 and 2.

[0043] The ratio (T / W) of the thickness (T) of the spring member 10 to the width (W) of the thin wire 13A is the aspect ratio of the thin wire 13A. The aspect ratio of the inner thin wire 13A2 may be, for example, 3 or greater and 20 or less. The lower limit of the aspect ratio of the inner thin wire 13A2 may be 6, 8, or 12. The upper limit of the aspect ratio of the inner thin wire 13A2 may be 13, 10, or 5. The aspect ratio of the inner thin wire 13A2 can take multiple values ​​in the thickness direction of the spring member 10. That is, the aspect ratio at a first position, which is an arbitrary position in the thickness direction of the spring member 10, and the aspect ratio at a second position different from the first position can be different from each other. It is sufficient that the multiple values ​​that one inner thin wire 13A2 can take are within the range of 3 or greater and 20 or less.

[0044] The aspect ratio of the outer thin wire 13A1 may be, for example, 3 or more and 20 or less. The lower limit of the aspect ratio of the outer thin wire 13A1 may be 6, 8, or 12. The upper limit of the aspect ratio of the outer thin wire 13A1 may be 13, 10, or 5. The aspect ratio of the outer thin wire 13A1 may take multiple values ​​in the thickness direction of the spring member 10. That is, in the thickness direction of the spring member 10, the aspect ratio at a first position, which is an arbitrary position in the thickness direction, may be different from the aspect ratio at a second position different from the first position. It is sufficient that the multiple values ​​that one outer thin wire 13A1 can take are within the range of 3 or more and 20 or less.

[0045] By making the widths of the inner thin wire 13A2 and the outer thin wire 13A1 satisfy conditions 1 and 2, it is possible to suppress the occurrence of localized penetrations or breakage near the center of the thickness of the thin wire 13A during etching, and to suppress deformation of the thin wire 13A during operation, over a wide range of aspect ratios of the thin wire 13A.

[0046] The distance between the centers of the thin wires 13A in the direction in which the thin wires 13A are arranged is the pitch P of the thin wires 13A. The pitch P may be the distance between the centers of the thin wires 13A on the first surface 10S1 or the distance between the centers of the thin wires 13A on the second surface 10S2. In either case, the pitch P has the same value. The pitch P may be, for example, 200 μm or more and 500 μm or less, and preferably 240 μm or more and 400 μm or less.

[0047] The spring member 10 is formed from a metal having a high degree of hardness that allows it to achieve the spring load or deflection required for the spring member 10. The spring member 10 may be formed from, for example, a stainless steel alloy or a copper alloy. The stainless steel alloy may be, for example, a stainless steel alloy specified in JIS G 4313:2011 "Stainless steel strip for springs." The copper alloy may be, for example, a copper alloy specified in JIS H 3130:2018 "Beryllium copper, titanium copper, phosphor bronze, nickel-tin copper, and nickel silver plate and strip for springs."

[0048] The spring member 10 may include any one selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium-copper. The spring member 10 is preferably formed from any one selected from the above group. Since the spring member 10 can have high hardness, the durability of the spring member 10 can be increased.

[0049] 3A to 3C show examples of the cross-sectional shape of the inner thin wire 13A2, each of which is an example of the shape of the inner thin wire 13A2 in a cross section taken along line II-II in FIG.

[0050] 3A to 3C, each inner thin wire 13A2 has a pair of side surfaces extending along the thickness direction of the spring member 10, one of which is a first side surface 13A21 and the other of which is a second side surface 13A22. In each inner thin wire 13A2, the second side surface 13A22 has a shape obtained by flipping the first side surface 13A21 left and right.

[0051] Each inner thin wire 13A2 is adjacent to other thin wires 13A on both sides in the direction in which the thin wires 13A are arranged. Furthermore, the distance between the thin wires 13A is approximately the same in the direction in which the thin wires 13A are arranged. Therefore, during wet etching of the metal foil forming the spring member 10, the side surfaces 13A21, 13A22 of the inner thin wire 13A2 are formed by approximately the same amount and flow of etching solution. As a result, in a cross section perpendicular to the first surface 10S1, the second side surface 13A22 has a shape that is a left-right inversion of the first side surface 13A21.

[0052] 3A, each of the side surfaces 13A21 and 13A22 has a folded line shape with multiple bending points in the thickness direction of the spring member 10. Each of the side surfaces 13A21 and 13A22 has a shape in which two V-shapes recessed toward the center of the inner thin wire 13A2 are connected in the thickness direction of the spring member 10.

[0053] 3B , each of the side surfaces 13A21 and 13A22 includes a pair of inclined lines and a straight line sandwiched between the pair of inclined lines in the thickness direction of the spring member 10. Of the pair of inclined lines, the inclined line continuing to the first surface 10S1 has an inclination that narrows the width of the inner thin wire 13A2 in the direction from the first surface 10S1 to the second surface 10S2. Of the pair of inclined lines, the inclined line continuing to the second surface 10S2 has an inclination that narrows the width of the inner thin wire 13A2 in the direction from the second surface 10S2 to the first surface 10S1.

[0054] 3(C), each of the side surfaces 13A21, 13A22 has a V-shape with only one bending point in the thickness direction of the spring member 10. The first side surface 13A21 has a V-shape recessed from the first side surface 13A21 toward the second side surface 13A22. The second side surface 13A22 has a V-shape recessed from the second side surface 13A22 toward the first side surface 13A21. As a result, the inner thin wire 13A2 has a shape that is narrowed approximately at the center in the thickness direction of the spring member 10.

[0055] Figures 4(A) to 4(C) show an example of the cross-sectional shape of the outer thin wire 13A1. Each of Figures 4(A) to 4(C) shows an example of the shape of the outer thin wire 13A1 in a cross section taken along line II-II in Figure 1. The outer thin wire 13A1 shown in Figures 4(A) to 4(C) is an example of the outer thin wire 13A1 located on the right side of the pair of outer thin wires 13A1 in Figure 2. The outer thin wire 13A1 located on the left side in Figure 2 has a shape obtained by flipping the outer thin wire 13A1 located on the right side.

[0056] 4(A) to 4(C), in each outer thin wire 13A1, of a pair of side surfaces extending along the thickness direction of the spring member 10, the side surface closest to the inner thin wire 13A2 is the first side surface 13A11, and the side surface opposite to the first side surface 13A11 is the second side surface 13A12. In each outer thin wire 13A1, the first side surface 13A11 and the second side surface 13A12 have mutually different shapes.

[0057] Each outer thin wire 13A1 is adjacent to an inner thin wire 13A2 at the first side surface 13A11 in the direction in which the thin wires 13A are arranged, but does not have any thin wires 13A adjacent to the second side surface 13A12. Therefore, during wet etching of the metal foil forming the spring member 10, the second side surface 13A12 of the outer thin wire 13A1 comes into contact with more etching liquid than the first side surface 13A11 of the outer thin wire 13A1. Furthermore, the second side surface 13A12 is formed by an etching liquid with a different flow than the etching liquid used to form the first side surface 13A11. As a result, the first side surface 13A11 and the second side surface 13A12 of each outer thin wire 13A1 have different shapes.

[0058] 4A, the second side surface 13A12 may have a V-shape recessed from the second side surface 13A12 toward the first side surface 13A11. In this case, since the outer thin wire 13A1 is constricted at least on one side surface, the rigidity of the outer thin wire 13A1 is unlikely to be excessively high.

[0059] In the example shown in FIG. 4A , the second side surface 13A12 has a V-shape with only one bending point in the thickness direction of the spring member 10. The second side surface 13A12 has a V-shape that is recessed from the second side surface 13A12 toward the first side surface 13A11. The valley of the V-shape is located approximately in the center of the spring member 10 in the thickness direction. In contrast, the first side surface 13A11 has a folded line shape with multiple bending points in the thickness direction of the spring member 10. The first side surface 13A11 has a shape in which two V-shapes that are recessed toward the center of the outer thin wire 13A1 are connected in the thickness direction of the spring member 10. In the width direction of the spring member 10, the peak portion of the first side surface 13A11, which is the boundary between the two V-shapes, and the valley portion of the V-shape on the second side surface 13A12 are aligned.

[0060] 4(A), the second side surface 13A12 has a V-shape with only one bending point in the thickness direction of the spring member 10. The second side surface 13A12 has a V-shape that is recessed from the second side surface 13A12 toward the first side surface 13A11. The valley of the V-shape is located approximately in the center of the spring member 10 in the thickness direction.

[0061] In contrast, the first side surface 13A11 is composed of a pair of inclined lines and a straight line sandwiched between the pair of inclined lines in the thickness direction of the spring member 10. Of the pair of inclined lines, the inclined line continuing to the first surface 10S1 has an inclination that narrows the width of the outer thin wire 13A1 in the direction from the first surface 10S1 to the second surface 10S2. Of the pair of inclined lines, the inclined line continuing to the second surface 10S2 has an inclination that narrows the width of the outer thin wire 13A1 in the direction from the second surface 10S2 to the first surface 10S1.

[0062] In the example shown in FIG. 4C , the second side surface 13A12 has a concave shape recessed from the second side surface 13A12 toward the first side surface 13A11. The second side surface 13A12 has multiple bending points in the thickness direction of the spring member 10. In contrast, the first side surface 13A11 has a V-shape with only one bending point in the thickness direction of the spring member 10. The first side surface 13A11 has a V-shape recessed from the first side surface 13A11 toward the second side surface 13A12. The valley of the V-shape is located approximately in the center in the longitudinal direction of the spring member 10. In the width direction of the spring member 10, the bottom, which is the most recessed portion of the second side surface 13A12, and the valley of the first side surface 13A11 are aligned.

[0063] For each thin wire 13A, the variation in the width of the thin wire 13A in the thickness direction is ±2 μm or less from the average width of the thin wire 13A. For each thin wire 13A, the maximum width is equal to or less than the average width plus 2 μm, and the minimum width is equal to or greater than the average width minus 2 μm.

[0064] [Method of Manufacturing Spring Member] A method of manufacturing the spring member 10 will be described with reference to Figures 5 to 9. As shown in Figure 5, when manufacturing the spring member 10, first, a first resist layer PR1 is formed on the first surface 21S1 of the metal foil 21, and a second resist layer PR2 is formed on the second surface 21S2. Note that in the example described with reference to Figures 5 to 9, the resist layers PR1, PR2 are formed from positive photoresist, but the resist layers PR1, PR2 may also be formed from negative photoresist.

[0065] 6, a first photomask PM1 is placed on the first resist layer PR1, and a second photomask PM2 is placed on the second resist layer PR2. Then, the first resist layer PR1 is exposed using the first photomask PM1, and the second resist layer PR2 is exposed using the second photomask PM2.

[0066] As shown in FIG. 7, the exposed resist layers PR1 and PR2 are developed, thereby forming a first resist mask RM1 from the first resist layer PR1 and a second resist mask RM2 from the second resist layer PR2.

[0067] 8, the metal foil 21 is wet-etched using resist masks RM1 and RM2. During this process, the metal foil 21 is etched from both the first surface 21S1 and the second surface 21S2. As a result, through-holes are formed in the metal foil 21, penetrating the metal foil 21 in the thickness direction. As a result, an outer frame portion 11, an inner frame portion 12 spaced from the outer frame portion 11, and spring portions 13 connecting the inner frame portion 12 to the outer frame portion 11 are formed.

[0068] This results in the formation of a spring member 10 that satisfies the above-mentioned conditions 1 and 2, making it possible to suppress the occurrence of localized penetrations or breakage of each thin wire 13A near the center of the thickness direction during etching, and to suppress deformation of the inner thin wire 13A2 due to the driving of the spring member 10.

[0069] As shown in FIG. 9, the resist masks RM1 and RM2 are removed from the etched metal foil 21, and then the spring member 10 is cut out from the etched metal foil 21, thereby obtaining the spring member 10.

[0070] The metal foil 21 for forming the spring member 10 may include a base material and a copper layer. The base material may include any one selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium-copper. The base material has a first surface and a second surface opposite to the first surface. The copper layer may be located on at least one of the first surface and the second surface of the base material. That is, the copper layer may be located on both the first surface and the second surface, or only on the first surface or only on the second surface. The copper layer may be formed by, for example, vacuum deposition, sputtering, wet plating, or the like.

[0071] In addition, when the metal foil 21 includes a base material and one or more copper layers, the spring member 10 also includes the base material and one or more copper layers. The base material of the spring member 10 is a part of the base material of the metal foil 21, and the copper layer included in the spring member 10 is a part of the copper layer included in the metal foil 21. The base material has a first surface and a second surface opposite to the first surface. The copper layer is located on at least one of the first surface and the second surface. In other words, the copper layer may be located on both the first surface and the second surface of the base material, or may be located only on the first surface or only on the second surface.

[0072] [Examples] Examples and comparative examples will be described with reference to Figures 10 to 13. [Comparative Example 1-1] In Comparative Example 1-1, a metal foil 21 was prepared, which was a rolled material made of titanium copper and had a thickness of 120 µm. Next, resist masks RM1 and RM2 were formed on the first surface 21S1 and the second surface 21S2 of the metal foil 21, and the metal foil 21 was wet-etched from both the first surface 21S1 and the second surface 21S2 using the two resist masks RM1 and RM2. An aqueous solution of ferric chloride was used as the etching solution for the wet etching.

[0073] Within a 280 mm square region of the metal foil 21, unit areas each corresponding to one spring member 10 and having a square shape of 20 mm were arranged in a grid pattern so as to be spread out in both the rolling direction and the width direction of the metal foil 21. Therefore, in each of the resist masks RM1 and RM2, unit patterns corresponding to the shape of one spring member 10 were also arranged in a grid pattern so as to be spread out in both the rolling direction and the width direction.

[0074] FIG. 10 is a plan view schematically showing a portion of a unit pattern of the first resist mask RM1. FIG. 10 schematically shows a portion of the unit pattern corresponding to the spring portion 13 of the spring member 10. In FIG. 10, for convenience of illustration, the openings of the unit pattern are shown as rectangles. Note that the second resist mask RM2 has a different position relative to the metal foil 21 from the first resist mask RM1, but has the same shape as the first resist mask RM1. Therefore, the following description will focus on the shape of the first resist mask RM1, while omitting a description of the shape of the second resist mask RM2.

[0075] 10, the unit pattern has a plurality of openings in a portion corresponding to the spring portion 13. The plurality of openings are composed of two first openings RM1A1 located at the ends of the arrangement direction, which is the direction in which the openings are lined up, and a second opening RM1A2 sandwiched between the two first openings RM1A1. In the arrangement direction, the width of the first opening RM1A1 is a first width WA1, and the width of the second opening RM1A2 is a second width WA2.

[0076] In the first resist mask RM1, the portion sandwiched between the first opening RM1A1 and the second opening RM1A2 in the arrangement direction is the first linear portion RM11. In the arrangement direction, the portion sandwiched between the two second openings RM1A2 is the second linear portion RM12. After etching the metal foil 21, the portion covered with the first linear portion RM11 is the outer thin wire 13A1, and the portion covered with the second linear portion RM12 is the inner thin wire 13A2. After etching the metal foil 21, the unit pattern was formed so that six thin wires 13A were included in a cross section perpendicular to the first surface 21S1 and perpendicular to the direction in which the thin wires 13A extend.

[0077] In the first resist mask RM1, the pitch P between adjacent linear portions RM11 and RM12 in the arrangement direction was set to 240 μm. The first width WA1 of the first opening RM1A1 was set to 220 μm, and the second width WA2 of the second opening RM1A2 was set to 100 μm.

[0078] In addition, in a planar view facing the first surface 21S1 of the metal foil 21, multiple unit patterns were formed on each of the resist masks RM1 and RM2 so that the entirety of one unit pattern in the first resist mask RM1 overlaps the entirety of one unit pattern in the second resist mask RM2.

[0079] Using these resist masks RM1 and RM2, a plurality of etching patterns corresponding to the shape of the spring member 10 were formed on the metal foil 21.

[0080] [Comparative Examples 1-2 to 1-7] In Comparative Examples 1-2 to 1-7, the first width WA1 of the first opening RM1A1 was narrower and the width of the first linear portion RM11 was wider than in Comparative Example 1-1. Otherwise, the etching patterns of Comparative Examples 1-2 to 1-7 were obtained in the same manner as in Comparative Example 1-1.

[0081] In Comparative Example 1-8, the second width WA2 of the second opening RM1A2 was narrower and the width of the second linear portion RM12 was wider than in Comparative Example 1-1. Otherwise, the etching pattern of Comparative Example 1-8 was obtained in the same manner as in Comparative Example 1-1.

[0082] [Comparative Examples 1-9 and 1-10, Examples 1-1 to 1-4, and Comparative Examples 1-11 to 1-13] In Comparative Examples 1-9 and 1-10, Examples 1-1 to 1-4, and Comparative Examples 1-11 to 1-13, the first width WA1 of the first opening RM1A1 was narrower and the width of the first linear portion RM11 was wider than in Comparative Example 1-8. Otherwise, the etching patterns of Comparative Examples 1-9 and 1-10, Examples 1-1 to 1-4, and Comparative Examples 1-11 to 1-13 were obtained in the same manner as in Comparative Example 1-8.

[0083] In Example 1-5, the widths WA1 and WA2 of the openings RM1A1 and RM1A2 were narrower and the widths of the linear portions RM11 and RM12 were wider than in Comparative Example 1-1. Otherwise, the etching pattern of Example 1-5 was obtained in the same manner as in Comparative Example 1-1.

[0084] [Examples 1-6 to 1-8, Comparative Example 1-14] In Examples 1-6 to 1-8 and Comparative Example 1-14, the first width WA1 of the first opening RM1A1 was narrower and the width of the first linear portion RM11 was wider than in Example 1-5. Otherwise, the etching patterns of Examples 1-6 to 1-8 and Comparative Example 1-14 were obtained in the same manner as in Example 1-5.

[0085] In Comparative Example 2-1, the thickness of the metal foil 21 in Comparative Example 1-1 was changed to 150 μm, the pitch P was changed to 300 μm, and the widths WA1 and WA2 of the openings RM1A1 and RM1A2 were increased. Otherwise, the etching pattern of Comparative Example 2-1 was obtained by the same method as in Comparative Example 1-1.

[0086] In Comparative Examples 2-2 to 2-7, the first width WA1 of the first opening RM1A1 was narrower and the width of the first linear portion RM11 was wider than in Comparative Example 2-1. Otherwise, the etching patterns of Comparative Examples 2-2 to 2-7 were obtained in the same manner as in Comparative Example 2-1.

[0087] In Comparative Example 2-8, the second width WA2 of the second opening RM1A2 was narrower and the width of the second linear portion RM12 was wider than in Comparative Example 2-1. Otherwise, the etching pattern of Comparative Example 2-8 was obtained in the same manner as in Comparative Example 2-1.

[0088] [Comparative Examples 2-9 and 2-10, Examples 2-1 to 2-4, and Comparative Examples 2-11 to 2-13] In Comparative Examples 2-9 and 2-10, Examples 2-1 to 2-4, and Comparative Examples 2-11 to 2-13, the first width WA1 of the first opening RM1A1 was narrower and the width of the first linear portion RM11 was wider than in Comparative Example 2-8. Otherwise, the etching patterns of Comparative Examples 2-9 and 2-10, Examples 2-1 to 2-4, and Comparative Examples 2-11 to 2-13 were obtained in the same manner as in Comparative Example 2-8.

[0089] In Example 2-5, the widths WA1 and WA2 of the openings RM1A1 and RM1A2 were narrower and the widths of the linear portions RM11 and RM12 were wider than in Comparative Example 2-1. Otherwise, the etching pattern of Example 2-5 was obtained in the same manner as in Comparative Example 2-1.

[0090] [Examples 2-6 to 2-8, Comparative Example 2-14] In Examples 2-6 to 2-8 and Comparative Example 2-14, the first width WA1 of the first opening RM1A1 was narrower and the width of the first linear portion RM11 was wider than in Example 2-5. Otherwise, the etching patterns of Examples 2-6 to 2-8 and Comparative Example 2-14 were obtained in the same manner as in Example 2-5.

[0091] In Comparative Example 3-1, the thickness of the metal foil 21 in Comparative Example 1-1 was changed to 200 μm, the pitch P was changed to 400 μm, and the widths WA1 and WA2 of the openings RM1A1 and RM1A2 were increased. Otherwise, the etching pattern of Comparative Example 3-1 was obtained by the same method as in Comparative Example 1-1.

[0092] [Comparative Examples 3-2 to 3-7] In Comparative Examples 3-2 to 3-7, the first width WA1 of the first opening RM1A1 was narrower and the width of the first linear portion RM11 was wider than in Comparative Example 3-1. Otherwise, the etching patterns of Comparative Examples 3-2 to 3-7 were obtained in the same manner as in Comparative Example 3-1.

[0093] In Comparative Example 3-8, the second width WA2 of the second opening RM1A2 was narrower and the width of the second linear portion RM12 was wider than in Comparative Example 3-1. Otherwise, the etching pattern of Comparative Example 3-8 was obtained in the same manner as in Comparative Example 3-1.

[0094] [Comparative Examples 3-9 and 3-10, Examples 3-1 to 3-4, and Comparative Examples 3-11 to 3-13] In Comparative Examples 3-9 and 3-10, Examples 3-1 to 3-4, and Comparative Examples 3-11 to 3-13, the first width WA1 of the first opening RM1A1 was narrower and the width of the first linear portion RM11 was wider than in Comparative Example 3-8. Otherwise, the etching patterns of Comparative Examples 3-9 and 3-10, Examples 3-1 to 3-4, and Comparative Examples 3-11 to 3-13 were obtained in the same manner as in Comparative Example 3-8.

[0095] In Example 3-5, the widths WA1 and WA2 of the openings RM1A1 and RM1A2 were narrower and the widths of the linear portions RM11 and RM12 were wider than in Comparative Example 3-1. Otherwise, the etching pattern of Example 3-5 was obtained in the same manner as in Comparative Example 3-1.

[0096] [Examples 3-6 to 3-8, Comparative Example 3-14] In Examples 3-6 to 3-8 and Comparative Example 3-14, the first width WA1 of the first opening RM1A1 was narrower and the width of the first linear portion RM11 was wider than in Example 3-5. Otherwise, the etching patterns of Examples 3-6 to 3-8 and Comparative Example 3-14 were obtained in the same manner as in Example 3-5.

[0097] [Width of Thin Wires] Using a synthetic resin, the spring portions 13 of the etching pattern present in each metal foil 21 after etching were embedded. Then, by cutting the embedded spring portions 13 using a microtome, a cross section of the spring portions 13 in a plane perpendicular to the direction in which the thin wires included in the spring portions 13 extend and perpendicular to the first surface 21S1 was exposed.

[0098] The spring width was measured at the following positions on the cross section of the spring portion 13. That is, in the spring portion 13, the first width WS1 on the first surface 21S1 of the metal foil 21, the second width WS2 on the second surface 21S2 of the metal foil 21, and the widths of three planes sandwiched between the first surface 21S1 and the second surface 21S2 of the metal foil 21 among the planes that divide the spring portion 13 into four equal parts in the thickness direction were measured. When measuring the width of the spring portion 13, a digital microscope (VHX-6000, manufactured by Keyence Corporation) was used, and the magnification of the objective lens of the digital microscope was set to 100x.

[0099] For one spring portion 13 of each metal foil 21, the average value of the second width WS2 was calculated from the two outer thin wires 13A1, and the average value of the second width WS2 was calculated from the four inner thin wires 13A2. The average values ​​of the second widths WS2 for the ten spring portions 13 were then averaged to calculate the average value of the second width WS2 for the outer thin wires 13A1 and the average value of the second width WS2 for the inner thin wires 13A2. These average values ​​were set as the second widths WS2 of the thin wires 13A1 and 13A2 in each example and comparative example.

[0100] Furthermore, for one spring portion 13 of each metal foil 21, the average value of the first width WS1 was calculated from the two outer thin wires 13A1, and the average value of the first width WS1 was calculated from the four inner thin wires 13A2. Then, the average values ​​of the first widths WS1 for the ten spring portions 13 were averaged to calculate the average value of the first widths WS1 for the outer thin wires 13A1 and the average value of the first widths WS1 for the inner thin wires 13A2. These average values ​​were set as the first widths WS1 for the thin wires 13A1 and 13A2 in each example and comparative example.

[0101] Furthermore, in one spring portion 13 of each metal foil 21, the average width of each outer thin wire 13A1 was calculated at five locations, and further, the average width of two outer thin wires 13A1 was calculated. In this way, the average width of the outer thin wires 13A1 in one spring portion 13 was calculated. Then, by averaging the average widths of the outer thin wires 13A1 in ten spring portions 13, the average width of the outer thin wires 13A1 was calculated. In addition, in one spring portion 13 of each metal foil 21, the average width of each inner thin wire 13A2 was calculated at five locations, and further, the average width of four inner thin wires 13A2 was calculated. In this way, the average width of the inner thin wires 13A2 in one spring portion 13 was calculated. Then, by averaging the average widths of the inner thin wires 13A2 in ten spring portions 13, the average width of the inner thin wires 13A2 was calculated.

[0102] [Occurrence of localized through-holes and breakage in thin wires] After etching the metal foil 21, it was confirmed using a digital microscope (same as above) whether all etching patterns included in each metal foil 21 included thin wires 13A including localized through-holes near the center in the thickness direction or broken thin wires 13A. Note that a localized through-hole is a through-hole that penetrates a pair of side surfaces of the thin wire 13A. Whether the etching pattern included thin wires 13A including through-holes or broken thin wires 13A was evaluated using the following two levels.

[0103] ◯: The etching pattern does not include any thin wires 13A that have localized through-holes or broken thin wires 13A near the center in the thickness direction. ×: The etching pattern includes one or more thin wires 13A that have localized through-holes or broken thin wires 13A near the center in the thickness direction.

[0104] [Deformation of Thin Wires] Ten etching patterns included in each metal foil 21 were cut out as spring members 10. A dynamic test was then conducted in which the spring portion 13 was driven while the outer frame portion 11 of the spring member 10 was fixed. Thereafter, whether or not the spring member 10 contained deformed thin wires 13A was evaluated using the following two levels. When determining whether or not the spring member 10 contained deformed thin wires 13A, the spring member 10 was observed using a digital microscope (same as above).

[0105] ◯: After the dynamic test, the spring member 10 does not contain any deformed thin wires 13A. ×: After the dynamic test, the spring member 10 contains one or more deformed thin wires 13A.

[0106] [Evaluation Results] In the etching patterns of each example and each comparative example, the average value of the second width WS2 of each thin wire 13A, the presence or absence of through holes or breakage in the thin wire 13A, and the presence or absence of deformation of the thin wire 13A were evaluated, and the results are shown in Figures 11 to 13.

[0107] 11 to 13, when the width of the inner thin wire 13A2 was within the range of 6.0 μm to 6.6 μm, a localized penetration was observed near the center of the inner thin wire 13A2 in the thickness direction. The inner thin wire 13A2 was the narrowest part of the inner thin wire 13A2, and it was found that the inner thin wire 13A2 had a localized penetration near the center of the thickness direction of the spring member 10.

[0108] Furthermore, when the width of the inner thin wire 13A2 was within the range of 6.0 μm to 6.6 μm and the width of the outer thin wire 13A1 was less than 10 μm, a localized penetration was observed near the center of the thickness direction of the outer thin wire 13A1. The outer thin wire 13A1 was the narrowest part of the outer thin wire 13A1 and had a localized penetration near the center of the thickness direction of the spring member 10. On the other hand, even when the width of the inner thin wire 13A2 was within the range of 6.0 μm to 6.6 μm, no localized penetration or break was observed near the center of the thickness direction of the outer thin wire 13A1 when the width of the outer thin wire 13A1 was 10 μm or more.

[0109] Furthermore, when the width of the inner thin wire 13A2 was within the range of 6.0 μm to 6.6 μm, deformation of the inner thin wire 13A2 was observed, whereas when the width of the inner thin wire 13A2 was within the range of 6.0 μm to 6.6 μm, deformation of the outer thin wire 13A1 was not observed.

[0110] When the width of the inner thin wire 13A2 was within the range of 10.0 μm to 10.7 μm and the difference obtained by subtracting the width of the inner thin wire 13A2 from the width of the outer thin wire 13A1 was 2.0 μm or more, no localized penetration or disconnection was observed near the center of the thickness direction of the outer thin wire 13A1. On the other hand, when the width of the inner thin wire 13A2 was within the range of 10.0 μm to 10.7 μm and the difference obtained by subtracting the width of the inner thin wire 13A2 from the width of the outer thin wire 13A1 was less than 2.0 μm, a localized penetration was observed near the center of the thickness direction of the outer thin wire 13A1.

[0111] Furthermore, when the width of the inner thin wire 13A2 was within the range of 10.0 μm to 10.7 μm and the difference obtained by subtracting the width of the inner thin wire 13A2 from the width of the outer thin wire 13A1 was 8.0 μm or less, no deformation of the inner thin wire 13A2 was observed.On the other hand, when the width of the inner thin wire 13A2 was within the range of 10.0 μm to 10.7 μm and the difference obtained by subtracting the width of the inner thin wire 13A2 from the width of the outer thin wire 13A1 was more than 8.0 μm, deformation of the inner thin wire 13A2 was observed.

[0112] When the width of the inner thin wire 13A2 is within the range of 40.1 μm or more and 40.8 μm or less, and the difference between the width of the outer thin wire 13A1 and the width of the inner thin wire 13A2 is 2.0 μm or more, no localized penetrations or breaks were observed near the center of the thickness direction in the outer thin wire 13A1.

[0113] Furthermore, when the width of the inner thin wire 13A2 was within the range of 40.1 μm to 40.8 μm and the difference obtained by subtracting the width of the inner thin wire 13A2 from the width of the outer thin wire 13A1 was 8.0 μm or less, no deformation of the inner thin wire 13A2 was observed.On the other hand, when the width of the inner thin wire 13A2 was within the range of 40.1 μm to 40.8 μm and the difference obtained by subtracting the width of the inner thin wire 13A2 from the width of the outer thin wire 13A1 exceeded 8.0 μm, deformation of the inner thin wire 13A2 was observed.

[0114] It was confirmed that the average value of the first width WS1 of each thin wire 13A was equivalent to the average value of the second width WS2 shown in Figures 11 to 13. It was also confirmed that the variation of the width of each thin wire 13A from the average value was ±2 µm or less.

[0115] From these results, it can be said that local penetrations and breaks near the center of the thickness direction of the thin wire 13A during etching can be suppressed by the thin wire 13A included in the spring portion 13 satisfying the above-mentioned condition 1. Furthermore, it can be said that deformation of the thin wire 13A when the spring member 10 is driven can be suppressed by the thin wire 13A included in the spring portion 13 satisfying the above-mentioned condition 2.

[0116] As described above, the spring member for a camera module, the camera module, and the electronic device according to one embodiment can achieve the following effects. (1) When the spring member 10 satisfies condition 1 and the lower limit of condition 2, it is possible to prevent the inner thin wire 13A2 and the outer thin wire 13A1 from being penetrated or from being broken during etching. Furthermore, when the spring member 10 satisfies condition 1 and the upper limit of condition 2, it is possible to prevent the concentration of load on the inner thin wire 13A2 due to the actuation of the spring member 10. As a result, it is possible to prevent deformation of the inner thin wire 13A2 due to the actuation of the spring member 10.

[0117] (2) In the thickness direction of the spring member 10, the rigidity of the thin wire 13A is prevented from becoming excessively high compared to when the inside of the first width WS1 and the second width WS2 is thicker than the first width WS1 and the second width WS2.

[0118] (3) By setting the upper limit of the width of each thin wire 13A to 20 μm or less, it is possible to significantly obtain the effects of the width of the thin wire 13A satisfying conditions 1 and 2. (4) Since the outer thin wire 13A1 is constricted on at least one side, the rigidity of the outer thin wire 13A1 is unlikely to become excessively high.

[0119] (5) Since the spring member 10 can have high hardness, the durability of the spring member 10 can be increased.

[0120] The above-described embodiment can be modified as follows. [Spring portion] As described above, the spring portion 13 may have a folded line shape in which a single leaf spring is bent at multiple bends, or may be composed of multiple leaf springs that are independent of each other. When the spring member includes multiple leaf springs that are independent of each other, each leaf spring is connected to the inner frame portion and the outer frame portion.

[0121] REFERENCE SIGNS LIST 10...Spring member 10S1...First surface 10S2...Second surface 13...Spring portion 13A...Thin wire 13A1...Outer thin wire 13A11...First side surface 13A12...Second side surface 13A2...Inner thin wire

Claims

1. A spring component for a camera module, comprising: a first surface; and a second surface opposite to the first surface; and in a cross section perpendicular to the first surface, comprising three or more thin wires, the thin wires located at both ends being outer thin wires, and the thin wires sandwiched between the outer thin wires being inner thin wires, the inner thin wires having a width of 10 μm or more on the first surface and the second surface, and the outer thin wires having a width that is 2 μm to 8 μm thicker than the width of the inner thin wires on the first surface and the second surface.

2. A spring member according to claim 1, wherein, for each thin wire, the width at the first surface is a first width, the width at the second surface is a second width, and the first width and the second width are the first and second largest widths in the thickness direction of the spring member.

3. The spring member according to claim 2, wherein the first width and the second width of each thin wire are 20 μm or less.

4. A spring member according to any one of claims 1 to 3, wherein, of a pair of side surfaces of each outer thin wire extending along the thickness direction of the spring member, the side surface that is closer to the inner thin wire is a first side surface, and the side surface opposite to the first side surface is a second side surface, and the second side surface has a V-shape recessed from the second side surface toward the first side surface.

5. A spring member according to any one of claims 1 to 3, wherein the aspect ratio of the thin wire is 3 or more and 20 or less.

6. A spring member according to any one of claims 1 to 3, wherein the thickness of the spring member is 120 μm or more and 200 μm or less.

7. The spring member according to any one of claims 1 to 3, wherein the spring member includes any one selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium-copper.

8. The spring member according to any one of claims 1 to 3, wherein the spring member comprises a base material including any one selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium copper, the base material having a first surface and a second surface opposite to the first surface, and the spring member further comprises a copper layer on at least one of the first surface and the second surface of the base material.

9. A camera module comprising the spring member according to any one of claims 1 to 3.

10. An electronic device comprising the camera module according to claim 9.

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