Spring member, camera module, and electronic device

Abstract

The first edge includes a first bottom, a first top, and a second bottom located between a first end and a second end in a second direction. In the second direction, the first top is located between the first bottom and the second bottom. In the first direction, the distance between the central axis of the inner spring extending along the second direction and the first top is shorter than at least one of the distance between the central axis and the first end, and the distance between the central axis and the second end. In the first direction, the distance between the central axis and the first top is longer than the distance between the central axis and the first bottom, and the distance between the central axis and the second bottom.

Description

Technical Field

[0001] This disclosure relates to spring components, camera modules, and electronic devices. Background Technology

[0002] Camera modules in electronic devices such as tablets and smartphones that include cameras have drive mechanisms that enable autofocus and zoom. Known drive mechanisms include lens-driven and sensor-driven mechanisms. Lens-driven drive mechanisms include spring members capable of changing the position of the lens along its optical axis. In contrast, sensor-driven drive mechanisms include spring members capable of changing the position of an image sensor along the optical axis of the lens (see, for example, Patent Documents 1 and 2).

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2014-059345 Patent Document 2: Japanese Patent Application Publication No. 2020-170170 Summary of the Invention

[0004] The problem that the invention aims to solve The springs in the spring components are required to improve the uniformity of the spring width in the thickness direction.

[0005] Methods for solving problems A spring member for solving the above-mentioned problem includes: a first surface; a second surface opposite to the first surface; and a plurality of springs arranged along a first direction in a cross-section orthogonal to the first surface, including a pair of outer springs and an inner spring sandwiched between the outer springs in the first direction. The direction orthogonal to the first direction is a second direction. The inner spring has a first edge and a second edge opposite to each other in the first direction. The first edge includes a first end located on the first surface, a second end located on the second surface, and a first bottom, a first top, and a second bottom located between the first end and the second end in the second direction. In the second direction, the first top is located between the first bottom and the second bottom. In the first direction, the distance between the central axis of the inner spring extending along the second direction and the first top is shorter than at least one of the distance between the central axis and the first end and the distance between the central axis and the second end. In the first direction, the distance between the central axis and the first top is longer than the distance between the central axis and the first bottom and the distance between the central axis and the second bottom.

[0006] The spring component is formed by wet etching a metal foil for the spring component from both a first surface and a second surface. Since the wet etching of the metal foil is isotropic, the first and second edges of the inner spring formed on the metal foil by wet etching have an arc shape with a center of curvature outside the inner spring. Therefore, the inner spring has a necked shape between the first and second surfaces. Consequently, the difference between the spring width on each surface and the spring width at the necked portion tends to increase. Regarding this, according to the above-described spring component, since the first edge of the inner spring has a first bottom, a first top, and a second bottom, the amount of necking at each bottom can be reduced compared to the case where the inner spring is necked at one point in the thickness direction. Therefore, the uniformity of the spring width in the thickness direction can be improved in the inner spring.

[0007] In the above-described spring component, the second edge may include a third end located on the first surface, a fourth end located on the second surface, and a third bottom, a second top, and a fourth bottom located between the third end and the fourth end in the second direction. In the second direction, the second top is located between the third bottom and the fourth bottom. In the first direction, the distance between the central axis extending along the second direction and the second top is shorter than at least one of the distance between the central axis and the third end and the distance between the central axis and the fourth end. In the first direction, the distance between the central axis and the second top is longer than the distance between the central axis and the third bottom and the distance between the central axis and the fourth bottom.

[0008] According to the above spring component, in addition to the first edge, the second edge also has a third bottom, a second top and a fourth bottom. Therefore, compared with the case where only the first edge has two bottoms and a top sandwiched between the two bottoms, the uniformity of the thickness of the inner spring can be further improved.

[0009] In the above-described spring member, it is also possible that, in the second direction, the distance between the first top and the second top is shorter than the distance between the first top and the third bottom, and the distance between the first top and the fourth bottom.

[0010] According to the above-described spring component, the inner spring tends to have a maximum spring width between the first and second apexes in the second direction. Therefore, the inner spring is less likely to have a necking shape only at one point in the thickness direction, thus suppressing deviations in the spring width in the thickness direction within the inner spring.

[0011] In the above-described spring member, it is also possible that, in the second direction, the distance between the first top and the second top is shorter than the distance between the second top and the first bottom, and the distance between the second top and the second bottom.

[0012] In the above-described spring member, the width of the inner spring along the first direction may have a maximum value between the first top, the second top, or between the first top and the second top in the second direction.

[0013] In the above-described spring member, the width of the inner spring may have a first minimum value between the first end and the first top, and a second minimum value between the second end and the first top, wherein the percentage of the first minimum value relative to the maximum value and the percentage of the second minimum value relative to the maximum value are both 66% or more.

[0014] According to the above spring component, since the inner spring has a shape close to a rectangle, the strength of the inner spring can be improved.

[0015] In the above-described spring component, the width of the inner spring may have a first minimum value between the first end and the first top, and a second minimum value between the second end and the first top, in the second direction. The percentage of the distance between the maximum value and the first minimum value relative to the thickness of the inner spring, and the percentage of the distance between the maximum value and the second minimum value relative to the thickness of the inner spring, are both 24% or less.

[0016] According to the above-described spring component, the position in the inner spring where the width tapers along the first direction is close to the first top, thus improving the resistance to deformation in the inner spring.

[0017] In the above-described spring component, the width of the inner spring may have a first minimum value between the first end and the first top, and a second minimum value between the second end and the second top, in the second direction. The distance between the first minimum value and the second minimum value in the second direction is 39% or more and 46% or less relative to the thickness of the inner spring.

[0018] According to the above spring component, in the second direction, the shape of the inner spring is less prone to deviation, thus further improving the strength of the inner spring.

[0019] In the above-mentioned spring components, the thickness of the inner spring may be 150 μm or more.

[0020] Generally, the thicker the metal foil, the more the erosion of the metal foil progresses along the width direction of the spring when wet etching is performed, and therefore the more likely the necking of the inner spring will become significant. In this regard, according to the above spring component, even if a thick spring with a thickness of 150 μm or more is manufactured by wet etching of the metal foil, it is possible to suppress the increase of the difference between the minimum and maximum values ​​of the spring width in the thickness direction.

[0021] In the above-mentioned spring components, the spacing between the plurality of springs may be more than 100 μm and less than 200 μm, and the maximum width of each spring along the first direction may be less than 1 / 2 of the spacing.

[0022] According to the aforementioned spring component, near the spring, in the first direction, the etching amount of the metal foil increases to the point that more than half of the metal foil is etched, thus making the necking of the inner spring more pronounced. Therefore, the effect resulting from the inner spring having a first edge can be significantly obtained.

[0023] In the above-described spring component, the spring component may also include a base material selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Cosun alloy and titanium copper, the base material having a first surface and a second surface located on the side opposite to the first surface of the base material, and the spring component further having a copper layer on at least one of the first surface and the second surface of the base material.

[0024] The camera module used to solve the above-mentioned problem has the aforementioned spring component.

[0025] The electronic device used to solve the above-mentioned problem includes the aforementioned camera module.

[0026] Invention Effects According to the spring component disclosed herein, the uniformity of the spring width in the thickness direction can be improved in the inner spring. Attached Figure Description

[0027] Figure 1 This is a top view showing the structure of a spring member according to one embodiment.

[0028] Figure 2 It means along Figure 1 A cross-sectional view of the structure of line II-II shown.

[0029] Figure 3 It means Figure 2 A cross-sectional view of the inner spring structure of the spring component shown.

[0030] Figure 4 This is a process diagram showing one step in the manufacturing process of a spring component.

[0031] Figure 5 This is a process diagram showing one step in the manufacturing process of a spring component.

[0032] Figure 6 This is a process diagram showing one step in the manufacturing process of a spring component.

[0033] Figure 7 This is a process diagram showing one step in the manufacturing process of a spring component.

[0034] Figure 8 This is a process diagram showing one step in the manufacturing process of a spring component.

[0035] Figure 9 This is a process diagram showing one step of the manufacturing method of the spring component in Test Example 3.

[0036] Figure 10 This is a process diagram showing one step in the manufacturing method of the spring component in Test Example 3.

[0037] Figure 11 This is a process diagram showing one step in the manufacturing method of the spring component in Test Example 3.

[0038] Figure 12 This is a process diagram showing one step in the manufacturing method of the spring component in Test Example 5.

[0039] Figure 13 This is a process diagram showing one step in the manufacturing method of the spring component in Test Example 5.

[0040] Figure 14 This is a process diagram showing one step in the manufacturing method of the spring component in Test Example 5.

[0041] Figure 15 This is a table representing the evaluation results of Experiment Example 1.

[0042] Figure 16 This is a table representing the evaluation results of test example 2.

[0043] Figure 17 This is a table representing the evaluation results of test example 3.

[0044] Figure 18 This is a table representing the evaluation results of test example 4.

[0045] Figure 19 This is a table representing the analytical results of Experiment Example 1.

[0046] Figure 20 This is a table representing the analytical results of Experiment Example 2.

[0047] Figure 21 This is a table representing the analytical results of Experiment Example 3.

[0048] Figure 22 This is a table representing the analytical results of Experiment Example 4. Detailed Implementation

[0049] Reference Figures 1 to 22 An embodiment of the spring component will be described.

[0050] [Spring component] Reference Figures 1 to 3 The spring components will be explained.

[0051] like Figure 1 As shown, the spring member 10 for the camera module has a first surface 10S1 and a second surface 10S2 opposite to the first surface 10S1. The spring member 10 has an outer frame portion 11, an inner frame portion 12, and a spring portion 13. The spring portion 13 is a leaf spring.

[0052] The spring section 13 includes a plurality of springs 13A. Viewed from a perspective opposite to the plane extending from the spring member 10, each spring 13A has a straight line extending along the plane extending from the spring member 10. Each spring 13A is part of the metal foil forming the spring member 10, and adjacent springs 13A are interconnected with each other through bends.

[0053] exist Figure 1 In the example shown, the outer frame 11 has an octagonal shape, and the inner frame 12 has a circular shape. The spring portion 13 has a zigzag shape. Furthermore, the shapes of the outer frame 11 and the inner frame 12 can be varied depending on the shapes of other components in the drive mechanism of the camera module carrying the spring member 10, i.e., components other than the spring member 10. The spring portion 13 can be constructed to appear as an arrangement of multiple springs 13A by having multiple bends in a single line, or it can be constructed as an arrangement of multiple independent springs 13A. The inner frame 12 is located within the area defined by the outer frame 11. The spring portion 13 connects the inner frame 12 to the outer frame 11.

[0054] In the lens-driven drive mechanism, a spring member 10 is disposed on one side of the lens in the optical axis direction. Alternatively, two spring members 10 are disposed such that they clamp the lens in the optical axis direction. In the optical axis direction, the position of the inner frame portion 12 connected to each outer frame portion 11 relative to the outer frame portion 11 changes, thereby changing the position of the lens in the optical axis direction. As a result, jitter can be corrected by the lens-driven drive mechanism.

[0055] In contrast, in a sensor-driven drive mechanism, a spring member 10 is disposed on one side of the image sensor along the optical axis of the lens. Alternatively, two spring members 10 are disposed such that they clamp the image sensor along the optical axis of the lens. The position of the image sensor along the optical axis of the lens is changed by altering the position of the inner frame portion 12, which is connected to each outer frame portion 11, relative to the outer frame portion 11. This allows for the correction of jitter using a sensor-driven drive mechanism.

[0056] Electronic devices equipped with a camera module having a spring member 10 can be, for example, mobile phone terminals, smartphones, tablet terminals, and laptop personal computers.

[0057] Figure 2 It shows along Figure 1 The cross-sectional structure of the spring section 13 of line II-II is shown. That is, Figure 2 The cross-sectional structure of the spring member 10 is shown along a plane orthogonal to the first surface 10S1 of the spring member 10 and to the direction in which each spring 13A extends.

[0058] like Figure 2 As shown, in a cross-section orthogonal to the first surface 10S1, the spring section 13 includes three or more springs 13A. In this cross-section, the springs 13A located at both ends in the direction in which they are arranged are outer springs 13A1. The direction in which the springs 13A are arranged is the first direction D1. The spring 13A sandwiched between the outer springs 13A1 in the first direction D1 is the inner spring 13A2. That is, the spring section 13 has a plurality of springs 13A arranged along the first direction D1 in a cross-section orthogonal to the first surface 10S1. The plurality of springs 13A includes a pair of outer springs 13A1 and an inner spring 13A2 sandwiched between the outer springs 13A1 in the first direction D1.

[0059] exist Figure 2 In the example shown, in a section orthogonal to the first surface 10S1, the spring section 13 includes six springs 13A. Therefore, in the first direction D1, four inner springs 13A2 are sandwiched between two outer springs 13A1. The plurality of springs 13A are arranged at approximately equal intervals in the first direction D1.

[0060] The width on the first surface 10S1 of each spring 13A is a first width WS1. The width on the second surface 10S2 of each spring 13A is a second width WS2. The inner spring 13A2 has a width of 10 μm or more on both the first surface 10S1 and the second surface 10S2. The first width WS1 of the inner spring 13A2 is 10 μm or more, and the second width WS2 is 10 μm or more.

[0061] The outer spring 13A1 has the same width as the inner spring 13A2 on the first surface 10S1 and the second surface 10S2. The outer spring 13A1 may also have a wider width than the inner spring 13A2.

[0062] The thickness of the spring member 10 can be 150 μm or more. The thickness of the spring member 10 is the distance between the first surface 10S1 and the second surface 10S2. That is, the thickness of the inner spring 13A2 can be 150 μm or more.

[0063] In the direction in which the springs 13A are arranged, the distance between the centers of the springs 13A is the spacing P of the springs 13A. The spacing P can be the distance between the centers of the springs 13A on the first surface 10S1, or it can be the distance between the centers of the springs 13A on the second surface 10S2. In either case, the spacing P is the same value. The spacing P can be, for example, greater than 100 μm and less than 200 μm.

[0064] The spring member 10 is formed of a metal with high hardness capable of achieving the required spring load or deflection. The spring member 10 may be formed, for example, of a stainless steel alloy or a copper alloy. The stainless steel alloy may be, for example, the stainless steel alloy specified in JIS G 4313:2011 "Stainless Steel Strip for Springs". The copper alloy may be, for example, the copper alloy specified in JIS H 3130:2018 "Plates and Strips of Beryllium Copper, Titanium Copper, Phosphor Bronze, Nickel-Tin Copper and Zinc-White Copper for Springs".

[0065] The spring member 10 may contain any material selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Cosun alloy, and titanium copper. The spring member 10 is preferably formed from any material selected from the above group. Because the spring member 10 can have high hardness, its durability can be improved.

[0066] Figure 3 A magnified view shows a cross-sectional structure of the inner spring 13A2 included in the spring member 10. Furthermore, in... Figure 3 In the example shown, the inner spring 13A2 has a linearly symmetrical shape about the central axis 13AA of the inner spring 13A2.

[0067] like Figure 3 As shown, the direction orthogonal to the first direction D1 is the second direction D2. The inner spring 13A2 has a first edge 13E1 and a second edge 13E2 opposite to each other in the first direction D1.

[0068] The first edge portion 13E1 includes a first end portion E1 located on the first surface 10S1, a second end portion E2 located on the second surface 10S2, and a first bottom portion B1, a first top portion T1, and a second bottom portion B2 located in the second direction D2 between the first end portion E1 and the second end portion E2. In the second direction D2, the first top portion T1 is located between the first bottom portion B1 and the second bottom portion B2.

[0069] The first edge 13E1 is a zigzag line with three inflection points. The three inflection points are the first bottom B1, the first top T1, and the second bottom B2. The bottom that is shorter from the first end E1 is the first bottom B1, and the bottom that is shorter from the second end E2 is the second bottom B2.

[0070] exist Figure 3 In the example shown, the first line segment connecting the first end E1 and the first bottom B1, the second line segment connecting the first bottom B1 and the first top T1, the third line segment connecting the first top T1 and the second bottom B2, and the fourth line segment connecting the second bottom B2 and the second end E2 are all straight. At least one of the first, second, third, and fourth line segments may also be curved. When each line segment is curved, each line segment may also have an arc shape in which the center of curvature of the line segment is located outside the inner spring 13A2. That is, each line segment may also have an arc shape that is concave towards the central axis 13AA. Alternatively, each line segment may also have an arc shape in which the center of curvature of the line segment is located inside the inner spring 13A2. That is, each line segment may also have an arc shape that bulges away from the central axis 13AA.

[0071] The central axis 13AA of the inner spring 13A2 can be an axis that passes through the center of the inner spring 13A2 on the first surface 10S1 and extends along the second direction D2, or it can be an axis that passes through the center of the inner spring 13A2 on the second surface 10S2 and extends along the second direction D2.

[0072] In the first direction D1, the distance DT1 between the central axis 13AA of the inner spring 13A2 extending along the second direction D2 and the first top T1 is shorter than the distance DE1 between the central axis 13AA and the first end E1, and the distance DE2 between the central axis 13AA and the second end E2. In the first direction D1, the distance DT1 between the central axis 13AA and the first top T1 is longer than the distance DB1 between the central axis 13AA and the first bottom B1, and the distance DB2 between the central axis 13AA and the second bottom B2.

[0073] In other words, in the first direction D1, the amount by which the first edge 13E1 protrudes from the first top T1 relative to the central axis 13AA is less than the amount by which the first end E1 and the second end E2 protrude relative to the central axis 13AA. Furthermore, in the first direction D1, the amount by which the first edge 13E1 protrudes from the first top T1 relative to the central axis 13AA is greater than the amount by which the first bottom B1 and the second bottom B2 protrude relative to the central axis 13AA.

[0074] The spring member 10 is formed by wet etching a metal foil for the spring member from both the first and second surfaces. Since the wet etching of the metal foil is isotropic, the first and second edges of the inner spring formed on the metal foil by wet etching have an arc shape with a center of curvature outside the inner spring. Therefore, the inner spring has a necked shape between the first and second surfaces. Consequently, the difference between the spring width on each surface and the spring width at the necked portion tends to increase. Regarding this, according to the spring member 10 of this disclosure, since the first edge 13E1 of the inner spring 13A2 has a first bottom B1, a first top T1, and a second bottom B2, the necking amount at each bottom B1 and B2 can be reduced compared to the case where the inner spring 13A2 is necked at one point in the thickness direction. Therefore, the uniformity of the spring width in the thickness direction can be improved in the inner spring 13A2.

[0075] The distance DT1 can be, for example, 10 μm or more and 20 μm or less. The distances DE1 and DE2 can be, for example, 16 μm or more and 25 μm or less. The distances DB1 and DB2 can be, for example, 5 μm or more and 15 μm or less.

[0076] The second edge portion 13E2 includes a third end portion E3 located on the first surface 10S1, a fourth end portion E4 located on the second surface 10S2, and a third bottom portion B3, a second top portion T2, and a fourth bottom portion B4 located in the second direction D2 between the third end portion E3 and the fourth end portion E4. In the second direction D2, the second top portion T2 is located between the third bottom portion B3 and the fourth bottom portion B4.

[0077] The second edge 13E2 is a zigzag line with three inflection points. The three inflection points are the third bottom B3, the second top T2, and the fourth bottom B4. The bottom that is shorter in distance from the third end E3 is the third bottom B3, and the bottom that is shorter in distance from the fourth end E4 is the fourth bottom B4.

[0078] exist Figure 3In the example shown, the first line segment connecting the third end E3 and the third bottom B3, the second line segment connecting the third bottom B3 and the second top T2, the third line segment connecting the second top T2 and the fourth bottom B4, and the fourth line segment connecting the fourth bottom B4 and the fourth end E4 are all straight. At least one of the first, second, third, and fourth line segments may also be curved. When each line segment is curved, each line segment may also have an arc shape with its center of curvature located outside the inner spring 13A2. That is, each line segment may also have an arc shape that is concave towards the central axis 13AA. Alternatively, each line segment may also have an arc shape with its center of curvature located within the inner spring 13A2. That is, each line segment may also have an arc shape that bulges away from the central axis 13AA.

[0079] In the first direction D1, the distance DT2 between the central axis 13AA extending along the second direction D2 and the second top T2 is shorter than the distance DE3 between the central axis 13AA and the third end E3, and the distance DE4 between the central axis 13AA and the fourth end E4. In the first direction D1, the distance DT2 between the central axis 13AA and the second top T2 is longer than the distance DB3 between the central axis 13AA and the third bottom B3, and the distance DB4 between the central axis 13AA and the fourth bottom B4.

[0080] In other words, in the first direction D1, the amount by which the second edge 13E2 protrudes from the second top T2 relative to the central axis 13AA is less than the amount by which it protrudes from the third end E3 and the fourth end E4 relative to the central axis 13AA. Furthermore, in the first direction D1, the amount by which the second edge 13E2 protrudes from the second top T2 relative to the central axis 13AA is greater than the amount by which it protrudes from the third bottom B3 and the fourth bottom B4 relative to the central axis 13AA.

[0081] In addition to the first edge portion 13E1, the second edge portion 13E2 also has a third bottom portion B3, a second top portion T2, and a fourth bottom portion B4. Therefore, compared to the case where only the first edge portion 13E1 has two bottom portions and a first top portion sandwiched between the two bottom portions, the uniformity of the spring width of the inner spring 13A2 can be further improved.

[0082] The distance DT2 can be, for example, 10 μm or more and 20 μm or less. The distances DE3 and DE4 can be, for example, 16 μm or more and 25 μm or less. The distances DB3 and DB2 can be, for example, 5 μm or more and 15 μm or less.

[0083] In the second direction D2, the distance between the first top T1 and the second top T2 can be shorter than the distance between the first top T1 and the third bottom B3, and the distance between the first top T1 and the fourth bottom B4. In this case, the inner spring 13A2 is more likely to have a maximum spring width between the first top T1 and the second top T2 in the second direction D2. Therefore, the inner spring 13A2 is less likely to have a necking shape only in the thickness direction, and thus, deviations in the spring width in the thickness direction can be suppressed in the inner spring 13A2.

[0084] In the second direction D2, the distance between the first top T1 and the second top T2 can be, for example, 0 μm or more and 10 μm or less. In the second direction D2, the distance between the first top T1 and the third bottom B3 can be, for example, 15 μm or more and 30 μm or less. In the second direction D2, the distance between the first top T1 and the fourth bottom B4 can be, for example, 15 μm or more and 30 μm or less.

[0085] In the second direction D2, the distance between the first top T1 and the second top T2 can be shorter than the distance between the second top T2 and the first bottom B1, and the distance between the second top T2 and the second bottom B2. In this case, the inner spring 13A2 is more likely to have a maximum spring width between the first top T1 and the second top T2 in the second direction D2. Therefore, the inner spring 13A2 is less likely to have a necking shape only in the thickness direction, and thus, deviations in the spring width in the thickness direction can be suppressed in the inner spring 13A2.

[0086] In the second direction D2, the distance between the first top T1 and the second top T2 can be, for example, 0 μm or more and 10 μm or less. In the second direction D2, the distance between the second top T2 and the first bottom B1 can be, for example, 15 μm or more and 30 μm or less. In the second direction D2, the distance between the second top T2 and the second bottom B2 can be, for example, 15 μm or more and 30 μm or less.

[0087] Between the first end E1 and the second end E2, from the viewpoint of maximizing the width W13A2 of the inner spring 13A2 along the first direction D1, it is preferable that the offset between the positions of the first top T1 and the second top T2 in the second direction D2 is small. Furthermore, between the first end E1 and the second end E2, from the viewpoint of maximizing the width W13A2 of the inner spring 13A2 along the first direction D1, it is more preferable that the positions of the first top T1 and the second top T2 are equal.

[0088] Furthermore, from the viewpoint of reducing the inflection point of the inner spring 13A2, it is preferable that the offset between the position of the first bottom B1 and the position of the third bottom B3 is small in the second direction D2, and it is also preferable that the positions of the first bottom B1 and the third bottom B3 are equal.

[0089] The width W13A2 of the inner spring 13A2 along the first direction D1 can have a maximum value at either the first top T1 or the second top T2. Therefore, since the inner spring 13A2 does not have a necking shape only in the thickness direction, deviations in the spring width in the thickness direction can be suppressed within the inner spring 13A2.

[0090] The width W13A2 of the inner spring 13A2 has a maximum value on either the first surface 10S1 or the second surface 10S2. From the viewpoint of improving the stiffness of the inner spring 13A2, the percentage of the maximum value to the maximum value in the width W13A2 of the inner spring 13A2 can be, for example, 45% or more, preferably 60% or more, and more preferably 75% or more.

[0091] In the spring member 10, the distance between the first top T1 and the second top T2 in the second direction D2 can also be shorter than the distance between the second top T2 and the first bottom B1, and the distance between the second top T2 and the second bottom B2. Furthermore, in the spring member 10, the width of the inner spring 13A2 along the first direction D1 can also have a maximum value between the first top T1, the second top T2, or between the first top T1 and the second top T2 in the second direction D2.

[0092] Furthermore, in the second direction D2, the width of the inner spring 13A2 can have a first minimum value between the first end E1 and the first top T1, and a second minimum value between the second end E2 and the first top T1. In the spring member 10, the percentage of the first minimum value to the maximum value and the percentage of the second minimum value to the maximum value can both be 66% or more. Therefore, the inner spring 13A2 has a nearly rectangular shape, thus improving its strength.

[0093] Alternatively, in the spring member 10, the percentage of the distance between the maximum and the first minimum values ​​relative to the thickness of the inner spring 13A2, and the percentage of the distance between the maximum and the second minimum values ​​relative to the thickness of the inner spring 13A2, may both be 24% or less. Therefore, the position in the inner spring 13A2 where the width tapers along the first direction D1 is closer to the first top T1, thus improving the resistance to deformation in the inner spring 13A2.

[0094] Furthermore, in the spring member 10, the percentage of the distance between the first minimum and the second minimum relative to the thickness of the inner spring 13A2 in the second direction D2 can be more than 39% and less than 46%. Therefore, the shape of the inner spring 13A2 is less prone to deviation in the second direction D2, thus further improving the strength of the inner spring 13A2.

[0095] As described above, the thickness of the inner spring 13A2 can be, for example, 150 μm or more. The thicker the metal foil, the more the erosion of the metal foil progresses along the width direction of the spring 13A when wet etching is performed, and therefore the necking of the inner spring 13A2 is more likely to become significant. In this regard, according to the spring member 10 of this embodiment, even if a thick spring 13A with a thickness of 150 μm or more is manufactured by wet etching of the metal foil, it is possible to suppress the increase of the difference between the minimum and maximum values ​​of the spring width in the thickness direction.

[0096] Furthermore, as described above, the spacing P among the plurality of springs 13A can be, for example, 100 μm or more and 200 μm or less, and the maximum width of each spring 13A along the first direction D1 can be less than half the spacing. In this case, near the spring 13A, in the first direction D1, the amount of etching of the metal foil becomes large enough to etch more than half of the metal foil, thus the necking of the inner spring 13A2 easily becomes significant. Therefore, the effect brought about by the inner spring 13A2 having the first edge 13E1 can be significantly obtained.

[0097] [Manufacturing method of spring components] Reference Figures 4 to 8 The manufacturing method of the spring component 10 will be described.

[0098] like Figure 4 As shown, a metal foil 21 is prepared for the spring component 10. The metal foil 21 includes a first surface 21S1 and a second surface 21S2 opposite to the first surface 21S1. The metal foil 21 may contain any material selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Cosun alloy, and titanium copper. The thickness of the metal foil 21 may be, for example, 150 μm or more.

[0099] Next, a first resist layer R1 is formed on the first surface 21S1 of the metal foil 21, and a second resist layer R2 is formed on the second surface 21S2. Each resist layer R1 and R2 can be formed using either a negative resist or a positive resist. Each resist layer R1 and R2 can be formed by coating or by adhering a dry film resist to the metal foil 21.

[0100] like Figure 5As shown, a resist pattern is formed by exposing and developing each resist layer R1 and R2. Specifically, a first resist pattern RP1 with a through hole RP1H is formed from the first resist layer R1, and a second resist pattern RP2 with a through hole RP2H is formed from the second resist layer R2.

[0101] like Figure 6 As shown, a metal foil 21 is wet-etched from both the first surface 21S1 and the second surface 21S2 using resist patterns RP1 and RP2. This forms a first recess 21R1 recessed from the first surface 21S1 and a second recess 21R2 recessed from the second surface 21S2 on the metal foil 21. Then, the first resist pattern RP1 is peeled off from the first surface 21S1, and the second resist pattern RP2 is peeled off from the second surface 21S2.

[0102] like Figure 7 As shown, a third resist pattern RP3 is formed on the first surface 21S1 of the metal foil 21, and a fourth resist pattern RP4 is formed on the second surface 21S2. First, a resist layer is formed on the entire first surface 21S1 along the inner surface of the first recess 21R1, and a resist layer is formed on the entire second surface 21S2 along the inner surface of the second recess 21R2. Next, the third resist pattern RP3 and the fourth resist pattern RP4 are formed by exposing and developing each resist layer. The third resist pattern RP3 has a through-hole RP3H located at the bottom of the first recess 21R1. The third resist pattern RP3 covers the side surface of the first recess 21R1. The fourth resist pattern RP4 has a through-hole RP4H located at the bottom of the second recess 21R2. The fourth resist pattern RP4 covers the side surface of the second recess 21R2.

[0103] like Figure 8 As shown, the metal foil 21 is wet-etched from both the first surface 21S1 and the second surface 21S2 using resist patterns RP3 and RP4. This forms a first hole 21H1 through the etching of the first recess 21R1 and a second hole 21H2 through the etching of the second recess 21R2. Furthermore, the first hole 21H1 and the second hole 21H2 are connected to form a through hole 21H penetrating the metal foil 21.

[0104] Each hole 21H1, 21H2 has a generally elliptical shape in a cross section orthogonal to the first surface 21S1. The portion of the metal foil 21 sandwiched between the two through holes 21H is an etched pattern 23A2. The etched pattern 23A2 corresponds to the inner spring 13A2 of the spring member 10.

[0105] According to the wet etching using the third resist pattern RP3 and the fourth resist pattern RP4, the resist patterns RP3 and RP4 have portions along the sides of the recesses 21R1 and 21R2. Therefore, the wet etching of the metal foil 21 can be easily performed anisotropically. That is, through the resist patterns RP3 and RP4, the etching solution can easily flow along the thickness direction, thus the etching of the metal foil 21 in the thickness direction can easily proceed.

[0106] According to the manufacturing method of such spring member 10, the inner spring 13A2 can be formed such that the first edge 13E1 and the second edge 13E2 of the inner spring 13A2 have three bends in the thickness direction. As a result, the inner spring 13A2 does not have a necked shape near the center in the thickness direction, and therefore, the etching pattern 23A2 that is cut off in the center in the thickness direction will not be formed due to the etching of the metal foil 21.

[0107] In addition, each top T1, T2 does not protrude further in the first direction D1 in the thickness direction than the ends E1, E2, E3, E4 that clamp the top T1, T2. Therefore, when using the spring member 10, it is possible to suppress the inner spring 13A2 from contacting the adjacent spring 13A.

[0108] The metal foil 21 used to form the spring member 10 may also have a base material and a copper layer. The base material may contain any material selected from the group consisting of stainless steel alloys, beryllium copper, nickel-tin copper, phosphor bronze, Cosun alloy, and titanium copper. The base material has a first side and a second side opposite to the first side. The copper layer may be located on at least one of the first and second sides of the base material. That is, the copper layer may be located on both the first and second sides, or only on the first side or only on the second side. The copper layer may be formed by methods such as vacuum evaporation, sputtering, and wet plating.

[0109] Furthermore, when the metal foil 21 has a base material and one or more copper layers, the spring member 10 also has a 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 of the spring member 10 is a part of the copper layer of the metal foil 21. The base material has a first side and a second side opposite to the first side. The copper layer is located on at least one of the first side and the second side. That is, the copper layer may be located on both the first and second sides of the base material, or it may be located only on the first side or only on the second side.

[0110] [Experimental Example] Reference Figures 4 to 22 The experimental examples will be explained.

[0111] [Experimental Example 1] Prepare a titanium-copper metal foil 21 with a thickness of 150 μm. Next, using a negative dry film resist (RY-5110UT, manufactured by Resonac Co., Ltd.) with a thickness of 15 μm, form a first resist layer R1 on the first side 21S1 of the metal foil 21 and a second resist layer R2 on the second side 21S2 of the metal foil 21.

[0112] A first resist pattern RP1 is formed by exposing and developing the first resist layer R1. A second resist pattern RP2 is formed by exposing and developing the second resist layer R2. At this time, in a cross-section orthogonal to the surfaces of each resist pattern RP1 and RP2 and along the direction of the etched patterns corresponding to the springs, the width of the through holes RP1H and RP2H of the resist patterns RP1 and RP2 is set to 30 μm. Furthermore, the through holes RP1H and RP2H are formed at equal intervals along the direction of the etched patterns, with a spring spacing P of 130 μm.

[0113] Next, the metal foil 21 is etched using a ferric chloride solution. This forms a first recess 21R1 on the first surface 21S1 of the metal foil 21 and a second recess 21R2 on the second surface 21S2. Then, the first resist pattern RP1 is peeled off from the first surface 21S1, and the second resist pattern RP2 is peeled off from the second surface 21S2.

[0114] Next, a resist layer with a thickness of 5 μm to 8 μm is formed on the first surface 21S1 and the second surface 21S2 of the metal foil 21 by electrodeposition. At this time, a positive photoresist for plating (Hani Resist AP-1000-D, manufactured by Nichiro Kasei Co., Ltd.) is used. Subsequently, by exposing and developing each resist layer, a third resist pattern RP3 is formed on the first surface 21S1, and a fourth resist pattern RP4 is formed on the second surface 21S2. At this time, through-holes RP3H and RP4H with a width of 38 μm are formed in each resist pattern RP3 and RP4. Furthermore, through-holes RP3H and RP4H are formed at equal intervals in the direction of the etched pattern arrangement, with a spring spacing P of 130 μm.

[0115] Then, the metal foil 21 is etched using a ferric chloride solution. This forms a through-hole 21H in the metal foil 21, consisting of a first hole 21H1 and a second hole 21H2. As a result, a metal foil 21 with two etched patterns 23A2 is obtained.

[0116] [Experimental Example 2] In Experiment 1, the widths of the through holes RP1H in the first resist pattern RP1 and RP2H in the second resist pattern RP2 were changed to 20 μm, and the spring spacing P was changed to 120 μm. The widths of the through holes RP3H in the third resist pattern RP3 and RP4H in the fourth resist pattern RP4 were changed to 28 μm. Otherwise, the metal foil 21 of Experiment 2 was obtained using the same method as in Experiment 1.

[0117] [Experimental Example 3] Reference Figures 9 to 11 Example 3 will be explained.

[0118] like Figure 9 As shown, in Experiment 3, a titanium-copper metal foil 21 with a thickness of 150 μm was prepared. Next, a first resist layer R1 was formed on the first surface 21S1 of the metal foil 21, and a second resist layer R2 was formed on the second surface 21S2. The titanium-copper metal foil 21, the first resist layer R1, and the second resist layer R2 in Experiment 3 are the same as those in Experiment 1.

[0119] like Figure 10 As shown, resist patterns are formed by exposing and developing each resist layer R1 and R2. Specifically, a first resist pattern RP51 with through-hole RP51H is formed from the first resist layer R1, and a second resist pattern RP52 with through-hole RP52H is formed from the second resist layer R2. At this time, the width of the through-hole RP51H and RP52H of each resist pattern RP51 and RP52 is set to 22 μm, and the through-holes RP51H and RP52H are formed at equal intervals in the direction of the etched pattern arrangement with a spring spacing P of 130 μm.

[0120] like Figure 11 As shown, a ferric chloride solution is used to etch the metal foil 21. This forms a through-hole 21H in the metal foil 21, consisting of a first hole 21H1 opening on a first surface 21S1 and a second hole 21H2 opening on a second surface 21S2. As a result, a metal foil 21 with an etched pattern 23A2 is obtained.

[0121] [Experimental Example 4] In Experiment 3, the width of the through hole RP51H of the first resist pattern RP51 and the width of the through hole RP51H of the second resist pattern RP52 were changed to 12 μm, and the spring spacing P was changed to 120 μm. Otherwise, the metal foil 21 of Experiment 4 was obtained by the same method as in Experiment 3.

[0122] [Experimental Example 5] Reference Figures 12 to 14 Example 5 will be explained.

[0123] like Figure 12 As shown, in Experimental Example 5, a titanium-copper metal foil 21 with a thickness of 150 μm was prepared. Next, a first resist layer R1 was formed on the first surface 21S1 of the metal foil 21, and a second resist layer R2 was formed on the second surface 21S2. The titanium-copper metal foil 21, the first resist layer R1, and the second resist layer R2 in Experimental Example 5 are the same as those in Experimental Example 1.

[0124] like Figure 13 As shown, resist patterns are formed by exposing and developing each resist layer R1 and R2. Specifically, a first resist pattern RP61 with a through-hole RP61H is formed from the first resist layer R1, and a second resist pattern RP62 with a through-hole RP62H is formed from the second resist layer R2. At this time, the width of the through-holes RP61H and RP62H in each resist pattern RP61 and RP62 is set to 38 μm, and the through-holes RP61H and RP62H are formed at equal intervals in the direction of the etched pattern arrangement with a spring spacing P of 130 μm.

[0125] like Figure 14 As shown, a ferric chloride solution is used to etch the metal foil 21. This forms a through-hole 21H in the metal foil 21, consisting of a first hole 21H1 opening on a first surface 21S1 and a second hole 21H2 opening on a second surface 21S2. As a result, a metal foil 21 with an etched pattern 23A2 is obtained.

[0126] [Experimental Example 6] In Experiment 5, the width of the through hole RP61H of the first resist pattern RP61 and the width of the through hole RP62H of the second resist pattern RP62 were set to 28 μm, and the spring spacing P was changed to 120 μm. Otherwise, the metal foil 21 of Experiment 6 was obtained using the same method as in Experiment 5.

[0127] [Evaluation Method] The portion of the metal foil 21 containing two etched patterns in each embodiment and each test example is cut out as a measurement sample. Next, the measurement sample is embedded in resin, thereby creating an embedded sample. The embedded sample is cut using a slicing machine to form a cross-sectional structure of the etched pattern, i.e., a cross-section along a plane orthogonal to the first surface 21S1.

[0128] The cross-section of the embedded sample was observed using an optical microscope (VHX-7000, manufactured by KEYENCE CORPORATION), and the positions of each end, bottom, and top of each etched pattern in the XY coordinate system were determined. The objective lens magnification was set to 200x. Furthermore, the positions of various parts within the etched pattern were determined using the thickness direction of the etched pattern as the Y-coordinate and the width direction of the etched pattern as the X-coordinate.

[0129] [Evaluation Results] The measurement results in each test case are as follows Figures 15 to 18 As shown. Furthermore, in test examples 5 and 6, as... Figure 14 As shown, it was confirmed that the etched pattern 23A2 formed on the metal foil 21 was cut off midway in the thickness direction. Therefore, the measurements of the embedded samples in Test Examples 5 and 6 were not performed.

[0130] exist Figures 15 to 18 In the measurement results shown, regarding the Y-coordinate, in both the direction from the first surface 21S1 towards the second surface 21S2 and the direction from the second surface 21S2 towards the first surface 21S1, after removing 2% of the measurement data, the minimum position in the direction from the first surface 21S1 towards the second surface 21S2 is set to 0. Furthermore, in Figures 15 to 18 In the measurement results shown, regarding the X-coordinate, at the first edge of the first etched pattern, the position where the X-coordinate value is minimum during measurement is set to 0. Furthermore, the first edge of the etched pattern corresponds to the first edge of the inner spring, and the second edge of the etched pattern corresponds to the second edge of the inner spring. In the second etched pattern, at the first edge, the position where the X-coordinate value is minimum during measurement is set to 0. Moreover, in each embodiment and each test example, the axis passing through the center of the etched pattern 23A2 in the second surface 21S2 and extending along the second direction is the central axis of the etched pattern 23A2.

[0131] like Figure 15 As shown, in Experimental Example 1, it was confirmed that: at the first edge of the first etched pattern, the position of the second end is (0, 145), the position of the second bottom is (8.8, 109), the position of the first top is (4.7, 73), the position of the first bottom is (8.6, 38), and the position of the first end is (2.2, 0). Furthermore, it was confirmed that: in the second edge, the position of the fourth end is (43.9, 145), the position of the fourth bottom is (32.5, 107), the position of the second top is (35.6, 76), the position of the third bottom is (29.9, 38), and the position of the third end is (38.2, 0).

[0132] It was confirmed that the spring width is 43.9 μm at the Y-coordinate position of 145 μm, 23.7 μm at the Y-coordinate position of 107 μm, 30.7 μm at the Y-coordinate position of 74 μm, 21.3 μm at the Y-coordinate position of 38 μm, and 35.9 μm at the Y-coordinate position of 0 μm.

[0133] It was confirmed that the spring width has a minimum value at the Y-coordinate positions of 107μm and 38μm, and a maximum value at the Y-coordinate position of 74μm.

[0134] Furthermore, it was confirmed that: at the first edge of the second etched pattern, the position of the second end is (0, 145), the position of the second bottom is (9.8, 105), the position of the first top is (4.8, 71), the position of the first bottom is (7.9, 36), and the position of the first end is (0.3, 0). Additionally, it was confirmed that: in the second edge, the position of the fourth end is (42.7, 145), the position of the fourth bottom is (30.7, 98), the position of the second top is (32.9, 78), the position of the third bottom is (28.0, 39), and the position of the third end is (35.8, 0).

[0135] It was confirmed that the spring width is 42.7 μm at the Y-coordinate position of 145 μm, 21.1 μm at the Y-coordinate position of 103 μm, 27.9 μm at the Y-coordinate position of 71 μm, 20.1 μm at the Y-coordinate position of 36 μm, and 35.5 μm at the Y-coordinate position of 0 μm.

[0136] It was confirmed that the spring width has a minimum value at the Y-coordinate positions of 103μm and 36μm, and a maximum value at the Y-coordinate position of 71μm.

[0137] Thus, in each etched pattern of Test Example 1, in the first direction D1, the amount by which the first top of the first edge protrudes relative to the central axis of the etched pattern is smaller than the amount by which each end protrudes relative to the central axis, but larger than the amount by which each bottom protrudes relative to the central axis. Furthermore, it was confirmed that in the first direction D1, the amount by which the second top of the second edge protrudes relative to the central axis of the etched pattern is smaller than the amount by which each end protrudes relative to the central axis, but larger than the amount by which each bottom protrudes relative to the central axis. That is, the above-described spring member 10 can be manufactured according to the manufacturing method of the spring member in Test Example 1. Moreover, as long as the above-described spring member 10 can be manufactured, the manufacturing method of the spring member 10 is not limited to the manufacturing method of the spring member 10 in Test Example 1.

[0138] like Figure 16As shown, in Experimental Example 2, it was confirmed that: at the first edge of the first etched pattern, the position of the second end is (0, 145), the position of the second bottom is (14.1, 92), the position of the first top is (12.2, 75), the position of the first bottom is (14.2, 41), and the position of the first end is (3.5, 0). Furthermore, it was confirmed that: in the second edge, the position of the fourth end is (39.7, 145), the position of the fourth bottom is (29.6, 101), the position of the second top is (31.7, 78), the position of the third bottom is (27.1, 40), and the position of the third end is (36.6, 0).

[0139] It was confirmed that the spring width is 39.7 μm at the Y-coordinate position of 145 μm, 15.9 μm at the Y-coordinate position of 100 μm, 19.4 μm at the Y-coordinate position of 77 μm, 12.9 μm at the Y-coordinate position of 41 μm, and 33.1 μm at the Y-coordinate position of 0 μm.

[0140] It was confirmed that the spring width has a minimum value at the Y-coordinate positions of 100μm and 41μm, and a maximum value at the Y-coordinate position of 77μm.

[0141] Furthermore, it was confirmed that: at the first edge of the second etched pattern, the position of the second end is (0, 145), the position of the second bottom is (11.3, 102), the position of the first top is (6.4, 67), the position of the first bottom is (9.4, 32), and the position of the first end is (4.6, 0). Additionally, it was confirmed that: in the second edge, the position of the fourth end is (40.5, 145), the position of the fourth bottom is (28.0, 102), the position of the second top is (30.7, 72), the position of the third bottom is (28.9, 47), and the position of the third end is (39.1, 0).

[0142] It was confirmed that the spring width is 40.5 μm at the Y-coordinate position of 145 μm, 16.6 μm at the Y-coordinate position of 102 μm, 24.1 μm at the Y-coordinate position of 69 μm, 19.9 μm at the Y-coordinate position of 39 μm, and 34.5 μm at the Y-coordinate position of 0 μm.

[0143] It was confirmed that the spring width has a minimum value at the Y-coordinate positions of 102μm and 39μm, and a maximum value at the Y-coordinate position of 69μm.

[0144] Thus, in each etched pattern of Test Example 2, in the first direction D1, the amount by which the first top of the first edge protrudes relative to the central axis of the etched pattern is smaller than the amount by which each end protrudes relative to the central axis, but larger than the amount by which each bottom protrudes relative to the central axis. Furthermore, it was confirmed that, in the first direction D1, the amount by which the second top of the second edge protrudes relative to the central axis of the etched pattern is smaller than the amount by which each end protrudes relative to the central axis, but larger than the amount by which each bottom protrudes relative to the central axis. That is, it was confirmed that the spring member 10 can be manufactured according to the manufacturing method of the spring member in Test Example 2. Moreover, as long as the above-described spring member 10 can be manufactured, the manufacturing method of the spring member 10 is not limited to the manufacturing method of the spring member 10 in Test Example 2.

[0145] like Figure 17 As shown, in Experimental Example 3, it was confirmed that: at the first edge of the first etched pattern, the position of the second end is (0, 145), the position of the second bottom is (8.2, 110), the position of the first top is (6.9, 89), the position of the first bottom is (13.3, 39), and the position of the first end is (4.7, 0). Furthermore, it was confirmed that: in the second edge, the position of the fourth end is (44.9, 145), the position of the fourth bottom is (29.9, 111), the position of the second top is (47.4, 77), the position of the third bottom is (36.6, 36), and the position of the third end is (41.9, 0).

[0146] It was confirmed that the spring width is 44.9 μm at the Y-coordinate position of 145 μm, 29.9 μm at the Y-coordinate position of 111 μm, 39.4 μm at the Y-coordinate position of 77 μm, 23.4 μm at the Y-coordinate position of 39 μm, and 37.2 μm at the Y-coordinate position of 0 μm.

[0147] It was confirmed that the spring width has a minimum value at the Y-coordinate positions of 111μm and 39μm, and a maximum value at the Y-coordinate position of 77μm.

[0148] Furthermore, it was confirmed that: at the first edge of the second etched pattern, the position of the second end is (2.4, 145), the position of the second bottom is (9.6, 117), the position of the first top is (0, 76), the position of the first bottom is (10.7, 32), and the position of the first end is (4.1, 0). Additionally, it was confirmed that: in the second edge, the position of the fourth end is (49.1, 145), the position of the fourth bottom is (41.7, 115), the position of the second top is (50.5, 76), the position of the third bottom is (38.8, 33), and the position of the third end is (44.6, 0).

[0149] It was confirmed that the spring width is 46.7 μm at the Y-coordinate position of 145 μm, 32.2 μm at the Y-coordinate position of 116 μm, 50.5 μm at the Y-coordinate position of 76 μm, 28.1 μm at the Y-coordinate position of 33 μm, and 40.5 μm at the Y-coordinate position of 0 μm.

[0150] It was confirmed that the spring width has a minimum value at the Y-coordinate positions of 116μm and 33μm, and a maximum value at the Y-coordinate position of 76μm.

[0151] Thus, in the first etched pattern of Test Example 3, in the first direction D1, the amount by which the first top in the first edge protrudes relative to the central axis of the etched pattern is smaller than the amount by which each end protrudes relative to the central axis. On the other hand, the amount by which the second top in the second edge protrudes relative to the central axis of the etched pattern is larger than the amount by which each end protrudes relative to the central axis. Furthermore, it was confirmed that in the second etched pattern, the amount by which the first top in the first edge protrudes relative to the central axis of the etched pattern is larger than the amount by which each end protrudes relative to the central axis. Additionally, in the second etched pattern, in the first direction D1, the amount by which the second top in the second edge protrudes relative to the central axis of the etched pattern is larger than the amount by which each end protrudes relative to the central axis. Therefore, in the spring member of Test Example 3, the protruding tops contact each other during operation, thereby increasing the probability of damage to the spring member.

[0152] like Figure 18 As shown, in Experimental Example 4, it was confirmed that: at the first edge of the first etched pattern, the position of the second end is (3.2, 145), the position of the second bottom is (5.4, 113), the position of the first top is (0, 80), the position of the first bottom is (16.0, 35), and the position of the first end is (9.4, 0). Furthermore, it was confirmed that: in the second edge, the position of the fourth end is (58.0, 145), the position of the fourth bottom is (51.0, 113), the position of the second top is (58.1, 80), the position of the third bottom is (50.1, 33), and the position of the third end is (55.5, 0).

[0153] It was confirmed that the spring width is 54.8 μm at the Y-coordinate position of 145 μm, 42.4 μm at the Y-coordinate position of 113 μm, 50.1 μm at the Y-coordinate position of 80 μm, 34.1 μm at the Y-coordinate position of 33 μm, and 46.1 μm at the Y-coordinate position of 0 μm.

[0154] It was confirmed that the spring width has a minimum value at the Y-coordinate positions of 113μm and 33μm, and a maximum value at the Y-coordinate position of 80μm.

[0155] Furthermore, it was confirmed that: at the first edge of the second etched pattern, the position of the second end is (0, 145), the position of the second bottom is (4.0, 118), the position of the first top is (0.9, 84), the position of the first bottom is (13.6, 34), and the position of the first end is (6.8, 0). Additionally, it was confirmed that: in the second edge, the position of the fourth end is (50.3, 145), the position of the fourth bottom is (40.5, 106), the position of the second top is (44.1, 78), the position of the third bottom is (39.3, 42), and the position of the third end is (50.5, 0).

[0156] It was confirmed that the spring width is 50.3 μm at the Y-coordinate position of 145 μm, 37.0 μm at the Y-coordinate position of 110 μm, 43.1 μm at the Y-coordinate position of 80 μm, 26.0 μm at the Y-coordinate position of 39 μm, and 43.7 μm at the Y-coordinate position of 0 μm.

[0157] It was confirmed that the spring width has a minimum value at the Y-coordinate positions of 110μm and 39μm, and a maximum value at the Y-coordinate position of 80μm.

[0158] Thus, in the first etched pattern of Test Example 4, in the first direction D1, the amount by which the first top of the first edge protrudes relative to the central axis of the etched pattern is greater than the amount by which each end protrudes relative to the central axis. Furthermore, it was confirmed that the amount by which the second top of the second edge protrudes relative to the central axis of the etched pattern is greater than the amount by which each end protrudes relative to the central axis. Additionally, in the second etched pattern, in the first direction D1, the amount by which the first top of the first edge protrudes relative to the central axis of the etched pattern is greater than the amount by which the first end protrudes relative to the central axis. Therefore, in the spring member of Test Example 4, the protruding tops contact each other during operation, thereby increasing the probability of damage to the spring member.

[0159] Reference Figures 19 to 22 The analysis results of the etched patterns for each test example are explained. Furthermore, regarding the width of the etched pattern, the minimum value between the first end E1 and the first top T1 is referred to as the first minimum value, and the minimum value between the second end E2 and the first top T1 is referred to as the second minimum value.

[0160] In addition, Figures 19 to 22 In this diagram, L1 represents the first distance, T represents the thickness of the etched pattern, and L2 represents the second distance. Additionally, in... Figures 19 to 22 In the diagram, Aw is the width of the etched pattern on the second surface 21S2, Bw is the second minimum, Cw is the maximum, Dw is the first minimum, and Ew is the width of the etched pattern on the first surface 21S1.

[0161] like Figure 19 As shown, it was confirmed that in the first etched pattern of Experimental Example 1, the distance between the maximum value at the Y-coordinate and each position, i.e., the first distance, is 71 μm on the second surface 21S2, 33 μm at the second minimum value, 36 μm at the first minimum value, and 74 μm on the first surface. Furthermore, it was confirmed that the percentage of each first distance relative to the thickness of the etched pattern is 47.3% on the second surface 21S2, 22.0% at the second minimum value, 24.0% at the first minimum value, and 49.3% on the first surface 21S1. Additionally, it was confirmed that the distance between the first and second minimum values ​​at the Y-coordinate, i.e., the second distance, is 69 μm. Furthermore, it was confirmed that the percentage of the second distance relative to the thickness of the etched pattern is 46.0%.

[0162] It was confirmed that: In the first etched pattern, the percentage of the width at each location relative to the width on the second surface 21S2 is 100.0% on the second surface 21S2, 54.0% at the second minimum, 69.9% at the maximum, 48.5% at the first minimum, and 81.8% on the first surface 21S1. It was confirmed that: The percentage of the width at each location relative to the width on the first surface 21S1 is 122.3% on the second surface 21S2, 66.0% at the second minimum, 85.5% at the maximum, 59.3% at the first minimum, and 100.0% on the first surface 21S1. It was confirmed that the percentage of the second minimum relative to the maximum is 77.2%. It was confirmed that the percentage of the first minimum relative to the maximum is 69.4%.

[0163] In the second etched pattern of Experimental Example 1, it was confirmed that: the first distance was 74 μm on the second surface 21S2, 32 μm at the second minimum, 35 μm at the first minimum, and 71 μm on the first surface 21S1. Furthermore, it was confirmed that: the percentage of each first distance relative to the thickness of the etched pattern was 49.3% on the second surface 21S2, 21.3% at the second minimum, 23.3% at the first minimum, and 47.3% on the first surface 21S1. Additionally, the second distance was confirmed to be 67 μm. Furthermore, the percentage of the second distance relative to the thickness of the etched pattern was confirmed to be 44.7%.

[0164] It was confirmed that: In the second etched pattern, the percentage of the width at each location relative to the width on the second surface 21S2 is 100.0% on the second surface 21S2, 49.4% at the second minimum, 65.3% at the maximum, 47.1% at the first minimum, and 83.1% on the first surface 21S1. It was confirmed that: The percentage of the width at each location relative to the width on the first surface 21S1 is 120.3% on the second surface 21S2, 59.4% at the second minimum, 78.6% at the maximum, 56.6% at the first minimum, and 100.0% on the first surface 21S1. The width at the second minimum relative to the maximum is confirmed to be 75.6%. The width at the first minimum relative to the maximum is confirmed to be 72.0%.

[0165] like Figure 20 As shown, it was confirmed that in the first etched pattern of Experimental Example 2, the first distance was 68 μm on the second surface 21S2, 23 μm at the second minimum, 36 μm at the first minimum, and 77 μm on the first surface 21S1. Furthermore, it was confirmed that the percentage of each first distance relative to the thickness of the etched pattern was 45.3% on the second surface 21S2, 15.3% at the second minimum, 24.0% at the first minimum, and 51.3% on the first surface 21S1. Additionally, the second distance was confirmed to be 59 μm. Furthermore, the percentage of the second distance relative to the thickness of the etched pattern was confirmed to be 39.3%.

[0166] It was confirmed that: In the first etched pattern, the percentage of width at each location relative to the width on the second surface 21S2 is 100.0% on the second surface 21S2, 40.1% at the second minimum, 48.9% at the maximum, 32.5% at the first minimum, and 83.4% on the first surface 21S1. It was confirmed that: The percentage of width at each location relative to the width on the first surface 21S1 is 119.9% ​​on the second surface 21S2, 48.0% at the second minimum, 58.6% at the maximum, 39.0% at the first minimum, and 100.0% on the first surface 21S1. It was confirmed that the percentage of width at the second minimum relative to the maximum is 82.0%. It was confirmed that the percentage of width at the first minimum relative to the maximum is 66.5%.

[0167] It was confirmed that in the second etched pattern of Experimental Example 2, the first distance was 76 μm on the second surface 21S2, 33 μm at the second minimum, 30 μm at the first minimum, and 69 μm on the first surface 21S1. Furthermore, it was confirmed that the percentage of each first distance relative to the thickness of the etched pattern was 50.7% on the second surface 21S2, 22.0% at the second minimum, 20.0% at the first minimum, and 46.0% on the first surface. Additionally, the second distance was confirmed to be 63 μm. Furthermore, the percentage of the second distance relative to the thickness of the etched pattern was confirmed to be 42.0%.

[0168] It was confirmed that: In the second etched pattern, the percentage of width at each location relative to the width on the second surface 21S2 is 100.0% on the second surface 21S2, 41.0% at the second minimum, 59.5% at the maximum, 49.1% at the first minimum, and 85.2% on the first surface 21S1. It was confirmed that: The percentage of width at each location relative to the width on the first surface 21S1 is 117.4% on the second surface 21S2, 48.1% at the second minimum, 69.9% at the maximum, 57.7% at the first minimum, and 100.0% on the first surface 21S1. It was confirmed that the percentage of width at the second minimum relative to the maximum is 68.9%. It was confirmed that the percentage of width at the first minimum relative to the maximum is 82.6%.

[0169] like Figure 21 As shown, it was confirmed that in the first etched pattern of Experimental Example 3, the first distance was 68 μm on the second surface 21S2, 34 μm at the second minimum, 38 μm at the first minimum, and 77 μm on the first surface 21S1. Furthermore, it was confirmed that the percentage of each first distance relative to the thickness of the etched pattern was 45.3% on the second surface 21S2, 22.7% at the second minimum, 25.3% at the first minimum, and 51.3% on the first surface 21S1. Additionally, the second distance was confirmed to be 72 μm. Furthermore, the percentage of the second distance relative to the thickness of the etched pattern was confirmed to be 48.0%.

[0170] It was confirmed that: In the first etched pattern, the percentage of the width at each location relative to the width on the second surface 21S2 is 100.0% on the second surface 21S2, 66.6% at the second minimum, 87.8% at the maximum, 52.1% at the first minimum, and 82.9% on the first surface 21S1. It was confirmed that: The percentage of the width at each location relative to the width on the first surface 21S1 is 120.7% on the second surface 21S2, 80.4% at the second minimum, 105.9% at the maximum, 62.9% at the first minimum, and 100.0% on the first surface 21S1. It was confirmed that the percentage of the width at the second minimum relative to the maximum is 75.9%. It was confirmed that the percentage of the width at the first minimum relative to the maximum is 59.4%.

[0171] It was confirmed that in the second etched pattern of Experimental Example 3, the first distance was 69 μm on the second surface 21S2, 40 μm at the second minimum, 43 μm at the first minimum, and 76 μm on the first surface 21S1. It was confirmed that the percentage of the first distance relative to the thickness of the etched pattern was 46.0% on the second surface 21S2, 26.7% at the second minimum, 28.7% at the first minimum, and 50.7% on the first surface 21S1. Furthermore, the second distance was confirmed to be 83 μm. Furthermore, the percentage of the second distance relative to the thickness of the etched pattern was confirmed to be 55.3%.

[0172] It was confirmed that: In the second etched pattern, the percentage of width at each location relative to the width on the second surface 21S2 is 100.0% on the second surface 21S2, 69.0% at the second minimum, 108.1% at the maximum, 60.2% at the first minimum, and 86.7% on the first surface 21S1. It was confirmed that: The percentage of width at each location relative to the width on the first surface 21S1 is 115.3% on the second surface 21S2, 79.5% at the second minimum, 124.7% at the maximum, 69.4% at the first minimum, and 100.0% on the first surface 21S1. It was confirmed that the percentage of width at the second minimum relative to the maximum is 63.8%. It was confirmed that the percentage of width at the first minimum relative to the maximum is 55.6%.

[0173] like Figure 22As shown, it was confirmed that in the first etched pattern of Experimental Example 4, the first distance was 65 μm on the second surface 21S2, 33 μm at the second minimum, 47 μm at the first minimum, and 80 μm on the first surface 21S1. Furthermore, it was confirmed that the percentage of the first distance relative to the thickness of the etched pattern was 48.3% on the second surface 21S2, 22.0% at the second minimum, 31.3% at the first minimum, and 53.3% on the first surface 21S1. Additionally, the second distance was confirmed to be 80 μm. Furthermore, the percentage of the second distance relative to the thickness of the etched pattern was confirmed to be 58.3%.

[0174] It was confirmed that: In the first etched pattern, the percentage of the width at each location relative to the width on the second surface 21S2 is 100.0% on the second surface 21S2, 66.6% at the second minimum, 87.8% at the maximum, 52.1% at the first minimum, and 82.9% on the first surface 21S1. It was confirmed that: The percentage of the width at each location relative to the width on the first surface 21S1 is 120.7% on the second surface 21S2, 80.4% at the second minimum, 105.9% at the maximum, 62.9% at the first minimum, and 100.0% on the first surface 21S1. It was confirmed that the percentage of the width at the second minimum relative to the maximum is 75.9%. It was confirmed that the percentage of the width at the first minimum relative to the maximum is 59.4%.

[0175] It was confirmed that in the second etched pattern of Experimental Example 4, the first distance was 65 μm on the second surface 21S2, 30 μm at the second minimum, 41 μm at the first minimum, and 80 μm on the first surface 21S1. Furthermore, it was confirmed that the percentage of the first distance relative to the thickness of the etched pattern was 43.3% on the second surface 21S2, 20.0% at the second minimum, 27.3% at the first minimum, and 53.3% on the first surface 21S1. Additionally, the second distance was confirmed to be 71 μm. Furthermore, the percentage of the second distance relative to the thickness of the etched pattern was confirmed to be 47.3%.

[0176] It was confirmed that: In the second etched pattern, the percentage of the width at each location relative to the width on the second surface 21S2 is 100.0% on the second surface 21S2, 69.0% at the second minimum, 108.1% at the maximum, 60.2% at the first minimum, and 86.7% on the first surface 21S1. The ratio of the width at each location relative to the width on the first surface 21S1 is 115.3% on the second surface, 79.5% at the second minimum, 124.7% at the maximum, 69.4% at the first minimum, and 100.0% on the first surface 21S1. It was confirmed that the percentage of the width at the second minimum relative to the maximum is 63.8%. It was confirmed that the percentage of the width at the first minimum relative to the maximum is 55.6%.

[0177] That is, it was confirmed that in the etching patterns of Test Examples 1 and 2, the percentage of the first minimum relative to the maximum and the percentage of the second minimum relative to the maximum are both 66% or more. In contrast, it was confirmed that Test Examples 3 and 4 include etching patterns in which at least one of the percentage of the first minimum relative to the maximum and the percentage of the second minimum relative to the maximum is less than 66%.

[0178] Furthermore, it was confirmed that in the etched patterns of Test Examples 1 and 2, the percentage of the first distance at the first minimum value relative to the thickness of the etched pattern and the percentage of the first distance at the second minimum value relative to the thickness of the etched pattern were both 24% or less. In contrast, it was confirmed that Test Examples 3 and 4 included etched patterns in which at least one of the percentage of the first distance at the first minimum value relative to the thickness of the etched pattern and the percentage of the first distance at the second minimum value relative to the thickness of the etched pattern exceeded 24%.

[0179] Furthermore, it was confirmed that in the etched patterns of Test Examples 1 and 2, the percentage of the second distance relative to the etched pattern was within the range of 39% or more and 46% or less. In contrast, it was confirmed that in the etched patterns of Test Examples 3 and 4, the percentage of the second distance relative to the etched pattern exceeded 46%.

[0180] As explained above, according to one embodiment of the spring member, the following effects can be obtained.

[0181] (1) Since the first edge 13E1 of the inner spring 13A2 has a first bottom B1, a first top T1 and a second bottom B2, the amount of necking at each bottom B1 and B2 can be reduced compared to the case where the inner spring 13A2 is necked at one point in the thickness direction. As a result, the uniformity of the spring width in the thickness direction can be improved in the inner spring 13A2.

[0182] (2) In addition to the first edge 13E1, the second edge 13E2 may also have a third bottom B3, a second top T2 and a fourth bottom B4. In this case, compared with the case where only the first edge 13E1 has two bottoms and a top sandwiched between the two bottoms, the uniformity of the spring width of the inner spring 13A2 can be further improved.

[0183] (3) The inner spring 13A2 tends to have a maximum value of spring width between the first top T1 and the second top T2 in the second direction D2. Therefore, the inner spring 13A2 is less likely to have a necking shape only in the thickness direction, so the deviation of spring width in the thickness direction can be suppressed in the inner spring 13A2.

[0184] (4) The width of the inner spring 13A2 can also have a maximum value at the first top T1 or the second top T2. In this case, since the inner spring 13A2 does not have a necking shape only in the thickness direction, deviation of the spring width in the thickness direction can be suppressed in the inner spring 13A2.

[0185] (5) Even if a thick spring 13A with a thickness of more than 150 μm is manufactured by wet etching of metal foil 21, it is possible to suppress the increase of the difference between the minimum and maximum values ​​of the spring width in the thickness direction.

[0186] (6) Near the spring 13A, in the first direction D1, the etching amount of the metal foil 21 increases to the point that more than half of the metal foil 21 is etched, so the necking of the inner spring 13A2 easily becomes significant. Therefore, the effect of the inner spring 13A2 having the first edge 13E1 can be significantly obtained.

[0187] Furthermore, the above-described implementation methods can be modified as follows.

[0188] [First Section] The distance DT1 between the central axis 13AA and the first top T1 can also be longer than either the distance DE1 between the central axis 13AA and the first end E1, or the distance DE2 between the central axis 13AA and the second end E2. Even in this case, the same effect as described above (1) can be obtained by having the first bottom B1, the first top T1 and the second bottom B2 by the first edge 13E1.

[0189] [Second Edge Section] The distance DT2 between the central axis 13AA and the second top T2 can also be longer than either the distance between the central axis 13AA and the third end E3 or the distance between the central axis 13AA and the fourth end E4. Even in this case, the same effect as described above (2) can be obtained by having the third bottom B3, the second top T2 and the fourth bottom B4 by means of the second edge 13E2.

[0190] [Inner Spring] Alternatively, the first edge portion 13E1 may have a first bottom portion B1, a first top portion T1, and a second bottom portion B2, while the second edge portion 13E2 may not have a third bottom portion B3, a second top portion T2, and a fourth bottom portion B4. Even in this case, the effect based on (1) above can still be obtained.

[0191] Alternatively, the second edge 13E2 may have a third bottom B3, a second top T2, and a fourth bottom B4, while the first edge 13E1 may not have a first bottom B1, a first top T1, and a second bottom B2. Even in this case, the effect based on (1) above can still be obtained.

[0192] Explanation of reference numerals in the attached figures 10…Spring components; 11…Outer frame; 12…Inner frame section; 13…Spring section; 13A1…Outer spring; 13A2…Inner spring; 13E1…First Edge Part; 13E2…Second edge; B1…First bottom; B2…Second bottom; B3…Third bottom; B4…Fourth bottom; E1…First end; E2…second end; E3…Third end; E4…Fourth end; T1…First top; T2…Second top.

Claims

1. A spring component comprising: First impression; The second surface opposite to the first surface; and A plurality of springs are arranged along a first direction in a cross-section orthogonal to the first surface, and include a pair of outer springs and an inner spring sandwiched between the outer springs in the first direction. The direction orthogonal to the first direction is the second direction. The inner spring has a first edge and a second edge that are opposite each other in the first direction. The first edge includes a first end portion located on the first surface, a second end portion located on the second surface, and a first bottom portion, a first top portion, and a second bottom portion located between the first end portion and the second end portion in the second direction. In the second direction, the first top is located between the first bottom and the second bottom. In the first direction, the distance between the central axis of the inner spring extending along the second direction and the first top is shorter than at least one of the distance between the central axis and the first end, and the distance between the central axis and the second end. In the first direction, the distance between the central axis and the first top is longer than the distance between the central axis and the first bottom, and the distance between the central axis and the second bottom.

2. The spring member according to claim 1, wherein, The second edge includes a third end portion located on the first surface, a fourth end portion located on the second surface, and a third bottom portion, a second top portion, and a fourth bottom portion located in the second direction between the third end portion and the fourth end portion. In the second direction, the second top is located between the third bottom and the fourth bottom. In the first direction, the distance between the central axis extending along the second direction and the second top is shorter than at least one of the distance between the central axis and the third end, and the distance between the central axis and the fourth end. In the first direction, the distance between the central axis and the second top is longer than the distance between the central axis and the third bottom, and the distance between the central axis and the fourth bottom.

3. The spring member according to claim 2, wherein, In the second direction, the distance between the first top and the second top is shorter than the distance between the first top and the third bottom, and the distance between the first top and the fourth bottom.

4. The spring member according to claim 2, wherein, In the second direction, The distance between the first top and the second top is shorter than the distance between the second top and the first bottom, and the distance between the second top and the second bottom.

5. The spring member according to claim 2 or 4, wherein, The width of the inner spring along the first direction has a maximum value between the first top, the second top, or between the first top and the second top in the second direction.

6. The spring member according to claim 5, wherein, In the second direction, the width of the inner spring has a first minimum value between the first end and the first top, and a second minimum value between the second end and the first top. The percentage of the first minimum relative to the maximum and the percentage of the second minimum relative to the maximum are both 66% or more.

7. The spring member according to claim 5, wherein, In the second direction, the width of the inner spring has a first minimum value between the first end and the first top, and a second minimum value between the second end and the first top. In the second direction, the percentage of the distance between the maximum value and the first minimum value relative to the thickness of the inner spring, and the percentage of the distance between the maximum value and the second minimum value relative to the thickness of the inner spring, are both less than 24%.

8. The spring member according to claim 5, wherein, In the second direction, the width of the inner spring has a first minimum value between the first end and the first top, and a second minimum value between the second end and the second top. In the second direction, the distance between the first minimum and the second minimum is 39% or more and 46% or less relative to the thickness of the inner spring.

9. The spring member according to any one of claims 1 to 3, wherein, The thickness of the inner spring is 150 μm or more.

10. The spring member according to any one of claims 1 to 3, wherein, The spacing between the plurality of springs is greater than 100 μm and less than 200 μm. The maximum width of each spring along the first direction is less than 1 / 2 of the spacing.

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

12. A camera module comprising a spring member according to any one of claims 1 to 3.

13. An electronic device comprising the camera module of claim 12.

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