Spring components, camera modules, and electronic devices

Abstract

The present invention provides a spring member, a camera module, and electronic equipment that enable improved uniformity of spring width in the thickness direction. [Solution] The first edge portion 13E1 includes a first bottom portion B1, a first top portion T1, and a second bottom portion B2 located between the first end portion E1 and the second end portion E2 in the second direction D2. In the second direction D2, the first top portion T1 is located between the first bottom portion B1 and the second bottom portion B2. In the first direction D1, the distance between the central axis 13AA of the inner spring 13A2 extending along the second direction D2 and the first top portion T1 is shorter than at least one of the distance between the central axis 13AA and the first end portion E1, and the distance between the central axis 13AA and the second end portion E2. In the first direction D1, the distance between the central axis 13AA and the first top portion T1 is longer than the distance between the central axis 13AA and the first bottom portion B1, and the distance between the central axis 13AA and the second bottom portion B2.

Description

Technical Field

[0005]

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

Background Art

[0002] A camera module included in an electronic device with a camera such as a tablet terminal or a smartphone includes a drive mechanism for enabling autofocus and zoom. Known drive mechanisms include a lens drive method and a sensor drive method. The drive mechanism of the lens drive method includes a spring member that enables changing the position of the lens in the optical axis direction of the lens. In contrast, the drive mechanism of the sensor drive method includes a spring member that enables changing the position of the image sensor in the optical axis direction of the lens (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0006] The spring member is formed by wet etching a metal foil for the spring member from both a first and a second surface. Since the wet etching of the metal foil proceeds isotropically, the first and second edges of the inner spring formed on the metal foil by wet etching have an arc shape with the center of curvature outside the inner spring. As a result, the inner spring has a constricted shape between the first and second surfaces. This tends to increase the difference between the spring width at each surface and the spring width at the constricted portion. In this regard, with the above-described spring member, since the first edge of the inner spring has a first bottom, a first top, and a second bottom, it is possible to reduce the amount of constriction at each bottom compared to the case where the inner spring is constricted at one point in the thickness direction. This makes it possible to improve the uniformity of the spring width in the thickness direction in the inner spring.

[0007] In the spring member described above, the second edge portion 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 between the third end portion and the fourth end portion in the second direction, wherein the second top portion is located between the third bottom portion and the fourth bottom portion in the second direction, and the distance between the central axis extending along the second direction and the second top portion in the first direction is shorter than at least one of the distance between the central axis and the third end portion and the distance between the central axis and the fourth end portion, and the distance between the central axis and the second top portion in the first direction may be longer than the distance between the central axis and the third bottom portion and the distance between the central axis and the fourth bottom portion.

[0008] According to the above-described spring member, in addition to the first edge, the second edge has a third bottom, a second top, and a fourth bottom. Therefore, compared to the case where only the first edge has two bottoms and a top sandwiched between the two bottoms, it is possible to further improve the uniformity of the thickness in the inner spring.

[0009] In the spring member described above, the distance between the first apex and the second apex in the second direction may be shorter than the distance between the first apex and the third bottom, and the distance between the first apex and the fourth bottom.

[0010] According to the above spring member, the inner spring tends to have a maximum value in spring width between the first and second peaks in the second direction. As a result, the inner spring is less likely to have a constricted shape at only one point in the thickness direction, thus suppressing variation in spring width in the thickness direction of the inner spring.

[0011] In the spring member described above, the distance between the first apex and the second apex in the second direction may be shorter than the distance between the second apex and the first bottom, and the distance between the second apex and the second bottom.

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

[0013] In the above-described spring member, in the second direction, the width of the inner spring has a first minimum value between the first end and the first apex, and a second minimum value between the second end and the first apex, and the percentage of the first minimum value to the maximum value and the percentage of the second minimum value to the maximum value may be 66% or more.

[0014] According to the above spring member, the outer shape of the inner spring approaches a rectangular shape, making it possible to increase the strength of the inner spring.

[0015] In the above-described spring member, the width of the inner spring has a first minimum value between the first end and the first apex, and a second minimum value between the second end and the first apex. 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, may be 24% or less.

[0016] According to the above spring member, the position in the inner spring where the width along the first direction narrows approaches the first apex, making it possible to increase the resistance of the inner spring to deformation.

[0017] In the above-described spring member, in the second direction, the width of the inner spring has a first minimum value between the first end and the first apex, and a second minimum value between the second end and the first apex, and in the second direction, the percentage of the distance between the first minimum value and the second minimum value with respect to the thickness of the inner spring may be 39% or more and 46% or less.

[0018] According to the above spring member, in the second direction, the shape of the inner spring is less likely to be distorted, making it possible to further increase the strength of the inner spring.

[0019] In the spring member, the thickness of the inner spring may be 150 μm or more. Generally, the thicker the metal foil, when the metal foil is wet-etched, the erosion of the metal foil progresses along the width direction of the spring, so the constriction of the inner spring is likely to become remarkable. In this regard, according to the spring member, even when a thick spring having a thickness of 150 μm or more is manufactured by wet-etching of the metal foil, an increase in the difference between the minimum value and the maximum value of the spring width in the thickness direction can be suppressed.

[0020] In the spring member, the pitch of the plurality of springs may be 100 μm or more and 200 μm or less, and the maximum value in the width of each spring along the first direction may be 1 / 2 or less of the pitch.

[0021] According to the spring member, in the vicinity of the spring, since the etching amount of the metal foil becomes large enough to etch more than half of the metal foil in the first direction, the constriction of the inner spring is likely to become remarkable. Therefore, the effect due to the inner spring having the first edge portion can be remarkably obtained.

[0022] In the spring member, the spring member includes a base material selected from the group consisting of a stainless alloy, beryllium copper, nickel tin copper, phosphor bronze, Corson alloy, and titanium copper, the base material includes a first surface and a second surface located on the side opposite to the first surface of the base material, and the spring member may further include a copper layer on at least one of the first surface of the base material and the second surface of the base material.

[0023] A camera module for solving the above problems includes the spring member. An electronic device for solving the above problems includes the camera module.

Effect of the Invention

[0024] According to the spring member of the present disclosure, in the inner spring, the uniformity of the spring width in the thickness direction can be enhanced.

Brief Description of the Drawings

[0025] [Figure 1] Figure 1 is a plan view showing the structure of a spring member according to an embodiment. [Figure 2] Figure 2 is a cross-sectional view showing the structure along the line II-II shown in Figure 1. [Figure 3] Figure 3 is a cross-sectional view showing the structure of the inner spring included in the spring member shown in Figure 2. [Figure 4] Figure 4 is a process diagram showing a step in the manufacturing method of the spring member. [Figure 5] Figure 5 is a process diagram showing a step in the manufacturing method of the spring member. [Figure 6] Figure 6 is a process diagram showing a step in the manufacturing method of the spring member. [Figure 7] Figure 7 is a process diagram showing a step in the manufacturing method of the spring member. [Figure 8] Figure 8 is a process diagram showing a step in the manufacturing method of the spring member. [Figure 9] Figure 9 is a process diagram showing a step in the manufacturing method of the spring member in Test Example 3. [Figure 10] Figure 10 is a process diagram showing a step in the manufacturing method of the spring member in Test Example 3. [Figure 11] Figure 11 is a process diagram showing a step in the manufacturing method of the spring member in Test Example 3. [Figure 12] Figure 12 is a process diagram showing a step in the manufacturing method of the spring member in Test Example 5. [Figure 13] Figure 13 is a process diagram showing a step in the manufacturing method of the spring member in Test Example 5. [Figure 14] Figure 14 is a process diagram showing a step in the manufacturing method of the spring member in Test Example 5. [Figure 15] Figure 15 is a table showing the evaluation results of Test Example 1. [Figure 16] Figure 16 is a table showing the evaluation results of Test Example 2. [Figure 17] Figure 17 is a table showing the evaluation results for Test Example 3. [Figure 18] Figure 18 is a table showing the evaluation results for Test Example 4. [Figure 19] Figure 19 is a table showing the analysis results for Test Example 1. [Figure 20] Figure 20 is a table showing the analysis results for Test Example 2. [Figure 21] Figure 21 is a table showing the analysis results for Test Example 3. [Figure 22] Figure 22 is a table showing the analysis results for Test Example 4. [Modes for carrying out the invention]

[0026] An embodiment of the spring member will be described with reference to Figures 1 to 22. [Spring component] The spring members will be explained with reference to Figures 1 to 3. As shown in Figure 1, 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 includes an outer frame portion 11, an inner frame portion 12, and a spring portion 13. The spring portion 13 is a leaf spring.

[0027] The spring section 13 comprises a plurality of springs 13A. Each spring 13A has a linear shape that extends along the plane on which the spring member 10 expands, when viewed from a viewpoint opposite to the plane on which the spring member 10 expands. Each spring 13A is part of the metal foil forming the spring member 10, and adjacent springs 13A are connected to each other by a bend.

[0028] In the example shown in Figure 1, the outer frame portion 11 has an octagonal shape, and the inner frame portion 12 has a circular 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 according to the shapes of other components of the drive mechanism of the camera module on which the spring member 10 is mounted, i.e., components other than the spring member 10. The spring portion 13 may have a structure in which a single wire has multiple bends, making it appear as if multiple springs 13A are lined up, or it may have a structure in which multiple independent springs 13A are lined up. The inner frame portion 12 is located within the region defined by the outer frame portion 11. The spring portion 13 connects the inner frame portion 12 to the outer frame portion 11.

[0029] In a lens-driven mechanism, a spring member 10 is positioned on one side of the lens in the optical axis direction. Alternatively, two spring members 10 are positioned to sandwich the lens in the optical axis direction. By changing the position of the inner frame 12 connected to each outer frame 11 in the optical axis direction, the position of the lens in the optical axis direction changes. This makes it possible to correct camera shake using a lens-driven mechanism.

[0030] In contrast, in a sensor-driven drive mechanism, the spring member 10 is positioned on one side of the image sensor in the optical axis direction of the lens. Alternatively, two spring members 10 are positioned so as to sandwich the image sensor in the optical axis direction of the lens. By changing the position of the inner frame 12 connected to each outer frame 11 in the optical axis direction, the position of the image sensor in the optical axis direction of the lens changes. This makes it possible to correct camera shake using a sensor-driven drive mechanism.

[0031] The electronic device on which the camera module equipped with the spring member 10 is mounted may be, for example, a mobile phone terminal, a smartphone, a tablet terminal, or a notebook personal computer.

[0032] Figure 2 shows the cross-sectional structure of the spring portion 13 along the line II-II shown in Figure 1. That is, Figure 2 shows the cross-sectional structure of the spring member 10 along a plane perpendicular to the first surface 10S1 of the spring member 10, and perpendicular to the direction in which each spring 13A extends.

[0033] As shown in Figure 2, in a cross-section perpendicular to the first surface 10S1, the spring portion 13 includes three or more springs 13A. In this cross-section, of the springs 13A, the springs 13A located at both ends in the direction in which the springs 13A are aligned are the outer springs 13A1. The direction in which the springs 13A are aligned is the first direction D1. Of the multiple springs 13A, the spring 13A sandwiched between the outer springs 13A1 in the first direction D1 is the inner spring 13A2. That is, the spring portion 13 comprises multiple springs 13A aligned along the first direction D1 in a cross-section perpendicular to the first surface 10S1. The multiple springs 13A include a pair of outer springs 13A1 and inner springs 13A2 sandwiched between the outer springs 13A1 in the first direction D1.

[0034] In the example shown in Figure 2, the spring portion 13 contains six springs 13A in a cross-section perpendicular to the first surface 10S1. Therefore, in the first direction D1, four inner springs 13A2 are sandwiched between two outer springs 13A1. The multiple springs 13A are arranged at approximately equal intervals in the first direction D1.

[0035] Of each spring 13A, the width on the first surface 10S1 is the first width WS1. Of each spring 13A, the width on the second surface 10S2 is the second width WS2. The inner spring 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 spring 13A2 is 10 μm or more, and the second width WS2 is 10 μm or more.

[0036] 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 have a wider width than the inner spring 13A2.

[0037] The thickness of the spring member 10 may 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 may be 150 μm or more.

[0038] In the direction in which the springs 13A are aligned, the distance between the centers of the springs 13A is the pitch P of the springs 13A. The pitch P may be the distance between the centers of the springs 13A on the first surface 10S1, or the distance between the centers of the springs 13A on the second surface 10S2. In either case, the pitch P is an equivalent value. The pitch P may be, for example, between 100 μm and 200 μm.

[0039] The spring member 10 is formed from a metal having a hardness high enough to achieve the required spring load or deflection. 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 strips for springs". The copper alloy may be, for example, a copper alloy specified in JIS H 3130:2018 "Sheets and strips of beryllium copper, titanium copper, phosphor bronze, nickel-tin copper and nickel silver for springs".

[0040] The spring member 10 may include any of the following selected materials: stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium copper. It is preferable that the spring member 10 be formed from any of the above selected materials. Since the spring member 10 can have high hardness, it is possible to increase the durability of the spring member 10.

[0041] Figure 3 shows an enlarged view of one cross-sectional structure of the inner spring 13A2 of the spring member 10. In the example shown in Figure 3, the inner spring 13A2 has a line-symmetric shape with respect to its central axis 13AA.

[0042] As shown in Figure 3, the direction perpendicular to the first direction D1 is the second direction D2. The inner spring 13A2 has a first edge portion 13E1 and a second edge portion 13E2 that are opposite each other in the first direction D1.

[0043] 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 between the first end portion E1 and the second end portion E2 in the second direction D2. In the second direction D2, the first top portion T1 is located between the first bottom portion B1 and the second bottom portion B2.

[0044] The first edge portion 13E1 has a folded line shape with three inflection points. The three inflection points are the first bottom B1, the first apex T1, and the second bottom B2. Of the first bottom B1 and the second bottom B2, the bottom that is closer to the first end portion E1 is the first bottom B1, and the bottom that is closer to the second end portion E2 is the second bottom B2.

[0045] In the example shown in Figure 3, 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 apex T1, the third line segment connecting the first apex T1 and the second bottom B2, and the fourth line segment connecting the second bottom B2 and the second end E2 are all straight lines. At least one of the first, second, third, and fourth line segments may be curved. If each line segment is curved, each line segment may have an arc shape such that the center of curvature of the line segment is located outside the inner spring 13A2. That is, each line segment may have an arc shape that curves inward toward the central axis 13AA. Alternatively, each line segment may have an arc shape such that the center of curvature of the line segment is located inside the inner spring 13A2. That is, each line segment may have an arc shape that curves outward toward the central axis 13AA.

[0046] The central axis 13AA of the inner spring 13A2 may 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 may 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.

[0047] In the first direction D1, the distance DT1 between the central axis 13AA and the first apex T1 of the inner spring 13A2 extending along the second direction D2 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 apex 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.

[0048] In other words, in the first direction D1, the amount that the first edge 13E1 protrudes relative to the central axis 13AA at the first apex T1 is smaller than the amount that the first end E1 and second end E2 protrude relative to the central axis 13AA. Also, in the first direction D1, the amount that the first edge 13E1 protrudes relative to the central axis 13AA at the first apex T1 is larger than the amount that the first bottom B1 and second bottom B2 protrude relative to the central axis 13AA.

[0049] The spring member 10 is formed by wet etching a metal foil for the spring member from both a first surface and a second surface. Since the wet etching of the metal foil proceeds isotropically, the first and second edges of the inner spring formed on the metal foil by wet etching have an arc shape such that the center of curvature is outside the inner spring. As a result, the inner spring has a constricted shape between the first and second surfaces. This tends to increase the difference between the spring width on each surface and the spring width at the constricted portion. In this regard, 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, it is possible to reduce the amount of constriction at each bottom B1, B2 compared to the case where the inner spring 13A2 is constricted at one point in the thickness direction. This makes it possible to improve the uniformity of the spring width in the thickness direction of the inner spring 13A2.

[0050] Distance DT1 may be, for example, 10 μm or more and 20 μm or less. Distances DE1 and DE2 may be, for example, 16 μm or more and 25 μm or less. Distances DB1 and DB2 may be, for example, 5 μm or more and 15 μm or less.

[0051] 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 apex portion T2, and a fourth bottom portion B4 located between the third end portion E3 and the fourth end portion E4 in the second direction D2. In the second direction D2, the second apex portion T2 is located between the third bottom portion B3 and the fourth bottom portion B4.

[0052] The second edge portion 13E2 has a folded line shape with three inflection points. The three inflection points are the third bottom portion B3, the second apex portion T2, and the fourth bottom portion B4. Of the third bottom portion B3 and the fourth bottom portion B4, the bottom portion that is closer to the third end portion E3 is the third bottom portion B3, and the bottom portion that is closer to the fourth end portion E4 is the fourth bottom portion B4.

[0053] In the example shown in Figure 3, 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 apex T2, the third line segment connecting the second apex T2 and the fourth bottom B4, and the fourth line segment connecting the fourth bottom B4 and the fourth end E4 are all straight lines. At least one of the first, second, third, and fourth line segments may be curved. If each line segment is curved, each line segment may have an arc shape such that the center of curvature of the line segment is located outside the inner spring 13A2. That is, each line segment may have an arc shape that curves inward toward the central axis 13AA. Alternatively, each line segment may have an arc shape such that the center of curvature of the line segment is located inside the inner spring 13A2. That is, each line segment may have an arc shape that curves outward toward the central axis 13AA.

[0054] In the first direction D1, the distance DT2 between the central axis 13AA extending along the second direction D2 and the second apex 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 apex 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.

[0055] In other words, in the first direction D1, the amount of the second edge 13E2 that protrudes relative to the central axis 13AA at the second apex T2 is smaller than the amount that protrudes relative to the central axis 13AA at the third end E3 and the fourth end E4. Also, in the first direction D1, the amount of the second edge 13E2 that protrudes relative to the central axis 13AA at the second apex T2 is larger than the amount that protrudes relative to the central axis 13AA at the third bottom B3 and the fourth bottom B4.

[0056] In addition to the first edge portion 13E1, the second edge portion 13E2 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, it is possible to further improve the uniformity of the spring width in the inner spring 13A2.

[0057] Distance DT2 may be, for example, 10 μm or more and 20 μm or less. Distances DE3 and DE4 may be, for example, 16 μm or more and 25 μm or less. Distances DB3 and DB2 may be, for example, 5 μm or more and 15 μm or less.

[0058] In the second direction D2, the distance between the first apex T1 and the second apex T2 may be shorter than the distance between the first apex T1 and the third bottom B3, and the distance between the first apex T1 and the fourth bottom B4. In this case, the inner spring 13A2 is likely to have a maximum value in spring width between the first apex T1 and the second apex T2 in the second direction D2. As a result, the inner spring 13A2 is less likely to have a shape that is constricted at only one point in the thickness direction, and thus variation in spring width in the thickness direction of the inner spring 13A2 is suppressed.

[0059] In the second direction D2, the distance between the first apex T1 and the second apex T2 may be, for example, 0 μm or more and 10 μm or less. In the second direction D2, the distance between the first apex T1 and the third bottom B3 may be, for example, 15 μm or more and 30 μm or less. In the second direction D2, the distance between the first apex T1 and the fourth bottom B4 may be, for example, 15 μm or more and 30 μm or less.

[0060] In the second direction D2, the distance between the first apex T1 and the second apex T2 may be shorter than the distance between the second apex T2 and the first bottom B1, and the distance between the second apex T2 and the second bottom B2. In this case, the inner spring 13A2 is likely to have a maximum value in spring width between the first apex T1 and the second apex T2 in the second direction D2. As a result, the inner spring 13A2 is less likely to have a shape that is constricted at only one point in the thickness direction, and thus variation in spring width in the thickness direction of the inner spring 13A2 is suppressed.

[0061] In the second direction D2, the distance between the first apex T1 and the second apex T2 may be, for example, 0 μm or more and 10 μm or less. In the second direction D2, the distance between the second apex T2 and the first bottom B1 may be, for example, 15 μm or more and 30 μm or less. In the second direction D2, the distance between the second apex T2 and the second bottom B2 may be, for example, 15 μm or more and 30 μm or less.

[0062] From the viewpoint of maximizing the maximum value of the width W13A2 of the inner spring 13A2 along the first direction D1 between the first end E1 and the second end E2, it is preferable that the amount of displacement between the position of the first apex T1 and the position of the second apex T2 in the second direction D2 is small. Furthermore, from the viewpoint of maximizing the maximum value of the width W13A2 of the inner spring 13A2 along the first direction D1 between the first end E1 and the second end E2, it is more preferable that the position of the first apex T1 and the position of the second apex T2 are equal.

[0063] Furthermore, from the viewpoint of reducing the bending point in the inner spring 13A2, it is preferable that the amount of displacement 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 position of the first bottom B1 and the position of the third bottom B3 are equal.

[0064] The width W13A2 of the inner spring 13A2 along the first direction D1 may have a maximum value at the first peak T1 or the second peak T2. As a result, the inner spring 13A2 does not have a shape that is constricted at only one point in the thickness direction, and therefore the variation in the spring width in the thickness direction of the inner spring 13A2 is suppressed.

[0065] 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 increasing the rigidity of the inner spring 13A2, the percentage of the maximum value relative to the maximum value in the width W13A2 of the inner spring 13A2 may be, for example, 45% or more, preferably 60% or more, and more preferably 75% or more.

[0066] In the spring member 10, the distance between the first apex T1 and the second apex T2 in the second direction D2 may be shorter than the distance between the second apex T2 and the first bottom B1, and the distance between the second apex T2 and the second bottom B2. Also, in the spring member 10, the width of the inner spring 13A2 along the first direction D1 may have a maximum value at the first apex T1, the second apex T2, or between the first apex T1 and the second apex T2 in the second direction D2.

[0067] Furthermore, in the second direction D2, the width of the inner spring 13A2 may have a first minimum value between the first end E1 and the first apex T1, and a second minimum value between the second end E2 and the first apex 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, may be 66% or more. This makes the outer shape of the inner spring 13A2 closer to a rectangular shape, thus increasing the strength of the inner spring 13A2.

[0068] Furthermore, in the spring member 10, in the second direction D2, the percentage of the distance between the maximum value and the first minimum value with respect to the thickness of the inner spring 13A2, and the percentage of the distance between the maximum value and the second minimum value with respect to the thickness of the inner spring 13A2, may be 24% or less. As a result, the position in the inner spring 13A2 where the width along the first direction D1 narrows approaches the first apex T1, making it possible to increase the resistance of the inner spring 13A2 to deformation.

[0069] Furthermore, in the spring member 10, the percentage of the distance between the first minimum and the second minimum with respect to the thickness of the inner spring 13A2 in the second direction D2 may be 39% or more and 46% or less. This makes it less likely for the shape of the inner spring 13A2 to be distorted in the second direction D2, and thus makes it possible to further increase the strength of the inner spring 13A2.

[0070] As mentioned above, the thickness of the inner spring 13A2 may be, for example, 150 μm or more. The thicker the metal foil, the more the metal foil is eroded along the width direction of the spring 13A when the metal foil is wet etched, making the constriction of the inner spring 13A2 more pronounced. In this respect, according to the spring member 10 of this embodiment, even if a thick spring 13A having a thickness of 150 μm or more is manufactured by wet etching of the metal foil, the difference between the minimum and maximum values ​​of the spring width in the thickness direction is suppressed.

[0071] Furthermore, as described above, the pitch P of the multiple springs 13A may 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 may be 1 / 2 or less of the pitch. In this case, near the springs 13A, the amount of etching of the metal foil becomes large enough to etch more than half of the metal foil in the first direction D1, so the constriction of the inner spring 13A2 tends to become more pronounced. Therefore, the effect of the inner spring 13A2 having a first edge portion 13E1 can be significantly obtained.

[0072] [Method for manufacturing spring components] The manufacturing method of the spring member 10 will be explained with reference to Figures 4 to 8. As shown in Figure 4, a metal foil 21 for the spring member 10 is prepared. The metal foil 21 includes a first surface 21S1 and a second surface 21S2 which is the surface opposite to the first surface 21S1. The metal foil 21 may include, for example, any of the materials selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium copper. The thickness of the metal foil 21 may be, for example, 150 μm or more.

[0073] 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 may be formed from a negative-type resist or from a positive-type resist. Each resist layer R1 and R2 may be formed by coating, or by attaching a dry film resist to the metal foil 21.

[0074] As shown in Figure 5, a resist pattern is formed by exposing and developing each resist layer R1 and R2. Specifically, a first resist pattern RP1 having through holes RP1H is formed from the first resist layer R1, and a second resist pattern RP2 having through holes RP2H is formed from the second resist layer R2.

[0075] As shown in Figure 6, the metal foil 21 is wet-etched from both the first surface 21S1 and the second surface 21S2 using the respective 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. Subsequently, 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.

[0076] As shown in Figure 7, 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. In this process, first, a resist layer is formed over the entire surface of the first surface 21S1 so as to follow the inner surface of the first recess 21R1, and a resist layer is formed over the entire surface of the second surface 21S2 so as to follow the inner surface of the second recess 21R2. Subsequently, the third resist pattern RP3 and the fourth resist pattern RP4 are formed by exposure and development of 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.

[0077] As shown in Figure 8, the metal foil 21 is wet-etched from both the first surface 21S1 and the second surface 21S2 using the respective resist patterns RP3 and RP4. As a result, the etching of the first recess 21R1 progresses, forming the first hole 21H1, and the etching of the second recess 21R2 progresses, forming the second hole 21H2. Then, the first hole 21H1 is connected to the second hole 21H2, forming a through hole 21H that penetrates the metal foil 21.

[0078] Each of the holes 21H1 and 21H2 has a substantially elliptical shape in a cross-section perpendicular to the first surface 21S1. The portion of the metal foil 21 sandwiched between the two through holes 21H is the etching pattern 23A2. The etching pattern 23A2 corresponds to the inner spring 13A2 of the spring member 10.

[0079] In wet etching using the third resist pattern RP3 and the fourth resist pattern RP4, the resist patterns RP3 and RP4 have portions that follow the sides of the recesses 21R1 and 21R2. This makes it easier for the wet etching of the metal foil 21 to proceed anisotropically. That is, the resist patterns RP3 and RP4 make it easier for the etching solution to flow along the thickness direction, thus facilitating the etching of the metal foil 21 in the thickness direction.

[0080] According to this method for manufacturing the spring member 10, it is possible to form the inner spring 13A2 such that the first edge 13E1 and the second edge 13E2 of the inner spring 13A2 have three bent portions in the thickness direction. As a result, the inner spring 13A2 does not have a constricted shape near the center in the thickness direction, and therefore, etching of the metal foil 21 does not form an etching pattern 23A2 that is cut in the center in the thickness direction.

[0081] Furthermore, since each of the tops T1 and T2 does not protrude in the first direction D1 from the ends E1, E2, E3, and E4 that sandwich the tops T1 and T2 in the thickness direction, contact between the inner spring 13A2 and the adjacent spring 13A is suppressed when the spring member 10 is in use.

[0082] The metal foil 21 for forming the spring member 10 may comprise a base material and a copper layer. The base material may include any of the following selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium copper. The base material comprises 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 and second surfaces of the base material. That is, the copper layer may be located on both the first and second surfaces, or on only the first surface or only the second surface. The method for forming the copper layer may be, for example, vacuum deposition, sputtering, and wet plating.

[0083] Furthermore, if the metal foil 21 comprises a base material and one or more copper layers, the spring member 10 comprises 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 layers of the spring member 10 are a part of the copper layers of the metal foil 21. The base material comprises a first surface and a second surface opposite to the first surface. The copper layers are located on at least one of the first surface and the second surface. That is, the copper layers may be located on both the first surface and the second surface of the base material, or only on the first surface or only on the second surface.

[0084] [Example Test] Refer to Figures 4 through 22 to explain the test examples. [Test Example 1] A titanium copper metal foil 21 with a thickness of 150 μm was prepared. Next, a negative-type dry film resist (RY-5110UT, manufactured by Resonac Co., Ltd.) with a thickness of 15 μm was used to form a first resist layer R1 on the first surface 21S1 of the metal foil 21, and a second resist layer R2 on the second surface 21S2 of the metal foil 21.

[0085] A first resist pattern RP1 was formed by exposing and developing a first resist layer R1. A second resist pattern RP2 was formed by exposing and developing a second resist layer R2. In this process, the width of the through-holes RP1H and RP2H in the resist patterns RP1 and RP2 was set to 30 μm in a cross-section perpendicular to the surface of each resist pattern RP1 and RP2 and along the direction in which the etching patterns corresponding to the spring are aligned. Furthermore, the through-holes RP1H and RP2H were formed at equal intervals in the direction in which the etching patterns are aligned so that the pitch P in the spring is 130 μm.

[0086] Next, the metal foil 21 was etched using ferric chloride solution. This formed 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 was peeled off from the first surface 21S1, and the second resist pattern RP2 was peeled off from the second surface 21S2.

[0087] Next, a resist layer with a thickness of approximately 5 μm to 8 μm was formed on the first surface 21S1 and the second surface 21S2 of the metal foil 21 by electrodeposition. A positive-type photoresist for plating (Honey Resist AP-1000-D, manufactured by Honey Chemical Co., Ltd.) was used for this purpose. Subsequently, by exposing and developing each resist layer, a third resist pattern RP3 was formed on the first surface 21S1 and a fourth resist pattern RP4 was formed on the second surface 21S2. During this process, through holes RP3H and RP4H with a width of 38 μm were formed in each resist pattern RP3 and RP4. Furthermore, the through holes RP3H and RP4H were formed at equal intervals in the direction in which the etching patterns were aligned, so that the pitch P in the spring was 130 μm.

[0088] Subsequently, the metal foil 21 was etched using ferric chloride solution. This formed through holes 21H consisting of a first hole 21H1 and a second hole 21H2 in the metal foil 21. As a result, a metal foil 21 having two etching patterns 23A2 was obtained.

[0089] [Test Example 2] In Test Example 1, the width of the through-hole RP1H in the first resist pattern RP1 and the through-hole RP2H in the second resist pattern RP2 was changed to 20 μm, and the spring pitch P was changed to 120 μm. The width of the through-hole RP3H in the third resist pattern RP3 and the through-hole RP4H in the fourth resist pattern RP4 was changed to 28 μm. Otherwise, the metal foil 21 of Test Example 2 was obtained by the same method as in Test Example 1.

[0090] [Test Example 3] Refer to Figures 9 to 11 to explain Test Example 3. As shown in Figure 9, in Test Example 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 Test Example 3 were the same as those in Test Example 1.

[0091] As shown in Figure 10, resist patterns were formed by exposing and developing each resist layer R1 and R2. Specifically, a first resist pattern RP51 having through holes RP51H was formed from the first resist layer R1, and a second resist pattern RP52 having through holes RP52H was formed from the second resist layer R2. In this process, the width of the through holes RP51H and RP52H in each resist pattern RP51 and RP52 was set to 22 μm, and the through holes RP51H and RP52H were formed at equal intervals in the direction in which the etching patterns were aligned so that the spring pitch P was 130 μm.

[0092] As shown in Figure 11, the metal foil 21 was etched using ferric chloride solution. This formed through holes 21H in the metal foil 21, consisting of a first hole 21H1 opening on the first surface 21S1 and a second hole 21H2 opening on the second surface 21S2. As a result, a metal foil 21 having an etching pattern 23A2 was obtained.

[0093] [Test Example 4] In Test Example 3, the width of the through-hole RP51H in the first resist pattern RP51 and the width of the through-hole RP51H in the second resist pattern RP52 were changed to 12 μm, and the spring pitch P was changed to 120 μm. Otherwise, the metal foil 21 of Test Example 4 was obtained by the same method as in Test Example 3.

[0094] [Test Example 5] Refer to Figures 12 to 14 to explain Test Example 5. As shown in Figure 12, in Test 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 Test Example 5 were the same as those in Test Example 1.

[0095] As shown in Figure 13, resist patterns were formed by exposing and developing each resist layer R1 and R2. Specifically, a first resist pattern RP61 having through holes RP61H was formed from the first resist layer R1, and a second resist pattern RP62 having through holes RP62H was formed from the second resist layer R2. In this process, the width of the through holes RP61H and RP62H in each resist pattern RP61 and RP62 was set to 38 μm, and the through holes RP61H and RP62H were formed at equal intervals in the direction in which the etching patterns were aligned so that the spring pitch P was 130 μm.

[0096] As shown in Figure 14, the metal foil 21 was etched using ferric chloride solution. This formed through holes 21H in the metal foil 21, consisting of a first hole 21H1 opening on the first surface 21S1 and a second hole 21H2 opening on the second surface 21S2. As a result, a metal foil 21 having an etching pattern 23A2 was obtained.

[0097] [Test Example 6] In Test Example 5, the width of the through-hole RP61H in the first resist pattern RP61 and the width of the through-hole RP62H in the second resist pattern RP62 were set to 28 μm, and the spring pitch P was changed to 120 μm. Otherwise, the metal foil 21 of Test Example 6 was obtained by the same method as in Test Example 5.

[0098] [Evaluation Method] For each embodiment and each test example, portions of the metal foil 21 containing two etching patterns were cut out as measurement samples. Subsequently, embedded samples were prepared by embedding the measurement samples in resin. By cutting the embedded samples using a microtome, a cross-sectional structure of the etching pattern was formed, specifically a cross-section along a plane perpendicular to the first surface 21S1.

[0099] Using an optical microscope (VHX-7000, manufactured by Keyence Corporation), the cross-section of the embedded sample was observed, and the positions of each end, bottom, and top of each etching pattern in the XY coordinate system were measured. The objective lens magnification was set to 200x. Furthermore, the position of each part of the etching pattern was measured such that the thickness direction of the etching pattern was the Y coordinate and the width direction of the etching pattern was the X coordinate.

[0100] [Evaluation Results] The measurement results for each test example are shown in Figures 15 to 18. In test examples 5 and 6, as shown in Figure 14, it was observed that the etching pattern 23A2 formed on the metal foil 21 was cut midway along the thickness direction. Therefore, measurements were not performed on the embedded samples in test examples 5 and 6.

[0101] In the measurement results shown in Figures 15 to 18, for the Y coordinate, 2% of the measurement data was excluded in both the direction from the first surface 21S1 to the second surface 21S2 and the direction from the second surface 21S2 to the first surface 21S1, and the smallest position in the direction from the first surface 21S1 to the second surface 21S2 was set to 0. Also, in the measurement results shown in Figures 15 to 18, for the X coordinate, the position with the smallest X coordinate value at the time of measurement at the first edge of the first etching pattern was set to 0. Note that the first edge of the etching pattern corresponds to the first edge of the inner spring, and the second edge of the etching pattern corresponds to the second edge of the inner spring. In the second etching pattern, the position with the smallest X coordinate value at the time of measurement at the first edge was set to 0. In each embodiment and test example, the axis passing through the center of the etching pattern 23A2 on the second surface 21S2 and extending along the second direction is the central axis of the etching pattern 23A2.

[0102] As shown in Figure 15, in Test Example 1, it was observed that at the first edge of the first etching pattern, the position of the second end was (0,145), the position of the second bottom was (8,8,109), the position of the first apex was (4,7,73), the position of the first bottom was (8,6,38), and the position of the first end was (2,2,0). Furthermore, at the second edge, it was observed that the position of the fourth end was (43,9,145), the position of the fourth bottom was (32,5,107), the position of the second apex was (35,6,76), the position of the third bottom was (29,9,38), and the position of the third end was (38,2,0).

[0103] The spring width was found to be 43.9 μm at the Y-coordinate of 145 μm, 23.7 μm at the Y-coordinate of 107 μm, 30.7 μm at the Y-coordinate of 74 μm, 21.3 μm at the Y-coordinate of 38 μm, and 35.9 μm at the Y-coordinate of 0 μm.

[0104] It was observed that the spring width had local minimums at positions where the Y-coordinate was 107 μm and 38 μm, and a local maximum at a position where the Y-coordinate was 74 μm.

[0105] Furthermore, at the first edge of the second etching pattern, it was observed that the position of the second end was (0,145), the position of the second bottom was (9,8,105), the position of the first apex was (4,8,71), the position of the first bottom was (7,9,36), and the position of the first end was (0,3,0). Additionally, at the second edge, it was observed that the position of the fourth end was (42,7,145), the position of the fourth bottom was (30,7,98), the position of the second apex was (32,9,78), the position of the third bottom was (28,0,39), and the position of the third end was (35,8,0).

[0106] The spring width was found to be 42.7 μm at the Y-coordinate of 145 μm, 21.1 μm at the Y-coordinate of 103 μm, 27.9 μm at the Y-coordinate of 71 μm, 20.1 μm at the Y-coordinate of 36 μm, and 35.5 μm at the Y-coordinate of 0 μm.

[0107] It was observed that the spring width had local minimums at positions where the Y-coordinate was 103 μm and 36 μm, and a local maximum at a position where the Y-coordinate was 71 μm.

[0108] Thus, in each etching pattern of Test Example 1, it was observed that, in the first direction D1, the amount by which the first apex protrudes relative to the central axis of the etching pattern was smaller than the amount by which each end protrudes relative to the central axis, and larger than the amount by which each bottom protrudes relative to the central axis. Furthermore, in the first direction D1, it was observed that, in the second direction D1, the amount by which the second apex protrudes relative to the central axis of the etching pattern was smaller than the amount by which each end protrudes relative to the central axis, and larger than the amount by which each bottom protrudes relative to the central axis. In other words, it was confirmed that the spring member 10 described above can be manufactured by the manufacturing method of the spring member in Test Example 1. However, if the spring member 10 described above 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.

[0109] As shown in Figure 16, in Test Example 2, it was observed that at the first edge of the first etching pattern, the position of the second end was (0,145), the position of the second bottom was (14.1,92), the position of the first apex was (12.2,75), the position of the first bottom was (14.2,41), and the position of the first end was (3.5,0). Furthermore, at the second edge, it was observed that the position of the fourth end was (39.7,145), the position of the fourth bottom was (29.6,101), the position of the second apex was (31.7,78), the position of the third bottom was (27.1,40), and the position of the third end was (36.6,0).

[0110] The spring width was found to be 39.7 μm at the Y-coordinate of 145 μm, 15.9 μm at the Y-coordinate of 100 μm, 19.4 μm at the Y-coordinate of 77 μm, 12.9 μm at the Y-coordinate of 41 μm, and 33.1 μm at the Y-coordinate of 0 μm.

[0111] It was observed that the spring width had local minimums at positions where the Y-coordinate was 100 μm and 41 μm, and a local maximum at position where the Y-coordinate was 77 μm.

[0112] Furthermore, at the first edge of the second etching pattern, it was observed that the position of the second end was (0,145), the position of the second bottom was (11.3,102), the position of the first apex was (6.4,67), the position of the first bottom was (9.4,32), and the position of the first end was (4.6,0). Additionally, at the second edge, it was observed that the position of the fourth end was (40.5,145), the position of the fourth bottom was (28.0,102), the position of the second apex was (30.7,72), the position of the third bottom was (28.9,47), and the position of the third end was (39.1,0).

[0113] The spring width was found to be 40.5 μm at the Y-coordinate of 145 μm, 16.6 μm at the Y-coordinate of 102 μm, 24.1 μm at the Y-coordinate of 69 μm, 19.9 μm at the Y-coordinate of 39 μm, and 34.5 μm at the Y-coordinate of 0 μm.

[0114] It was observed that the spring width had local minimums at positions where the Y-coordinate was 102 μm and 39 μm, and a local maximum at a position where the Y-coordinate was 69 μm.

[0115] Thus, in each etching pattern of Test Example 2, it was observed that, in the first direction D1, the amount by which the first apex protrudes relative to the central axis of the etching pattern was smaller than the amount by which each end protrudes relative to the central axis, and larger than the amount by which each bottom protrudes relative to the central axis. Furthermore, in the first direction D1, it was observed that, in the second direction D1, the amount by which the second apex protrudes relative to the central axis of the etching pattern was smaller than the amount by which each end protrudes relative to the central axis, and larger than the amount by which each bottom protrudes relative to the central axis. In other words, it was confirmed that the spring member 10 can be manufactured by the manufacturing method of the spring member 10 in Test Example 2. It should be noted that, as long as the spring member 10 can be manufactured as described above, the manufacturing method of the spring member 10 is not limited to the manufacturing method of the spring member 10 in Test Example 2.

[0116] As shown in Figure 17, in Test Example 3, it was observed that at the first edge of the first etching pattern, the position of the second end was (0,145), the position of the second bottom was (8.2,110), the position of the first apex was (6.9,89), the position of the first bottom was (13.3,39), and the position of the first end was (4.7,0). Furthermore, at the second edge, it was observed that the position of the fourth end was (44.9,145), the position of the fourth bottom was (29.9,111), the position of the second apex was (47.4,77), the position of the third bottom was (36.6,36), and the position of the third end was (41.9,0).

[0117] The spring width was found to be 44.9 μm at the Y-coordinate of 145 μm, 29.9 μm at the Y-coordinate of 111 μm, 39.4 μm at the Y-coordinate of 77 μm, 23.4 μm at the Y-coordinate of 39 μm, and 37.2 μm at the Y-coordinate of 0 μm.

[0118] It was observed that the spring width had local minimums at positions where the Y-coordinate was 111 μm and 39 μm, and a local maximum at a position where the Y-coordinate was 77 μm.

[0119] Furthermore, at the first edge of the second etching pattern, it was observed that the position of the second end was (2.4,145), the position of the second bottom was (9.6,117), the position of the first apex was (0,76), the position of the first bottom was (10.7,32), and the position of the first end was (4.1,0). Additionally, at the second edge, it was observed that the position of the fourth end was (49.1,145), the position of the fourth bottom was (41.7,115), the position of the second apex was (50.5,76), the position of the third bottom was (38.8,33), and the position of the third end was (44.6,0).

[0120] The spring width was found to be 46.7 μm at the Y-coordinate of 145 μm, 32.2 μm at the Y-coordinate of 116 μm, 50.5 μm at the Y-coordinate of 76 μm, 28.1 μm at the Y-coordinate of 33 μm, and 40.5 μm at the Y-coordinate of 0 μm.

[0121] It was observed that the spring width had local minimums at positions where the Y-coordinate was 116 μm and 33 μm, and a local maximum at a position where the Y-coordinate was 76 μm.

[0122] Thus, in the first etching pattern of Test Example 3, in the first direction D1, the amount by which the first vertex protrudes relative to the central axis of the etching pattern from the first edge was smaller than the amount by which each end protrudes relative to the central axis, while in the second edge, the amount by which the second vertex protrudes relative to the central axis of the etching pattern was larger than the amount by which each end protrudes relative to the central axis. Furthermore, in the second etching pattern, the amount by which the first vertex protrudes relative to the central axis of the etching pattern from the first edge was larger than the amount by which each end protrudes relative to the central axis. Furthermore, in the second etching pattern, in the first direction D1, the amount by which the second vertex protrudes relative to the central axis of the second edge was 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 vertices come into contact with each other during operation, increasing the probability of damage to the spring member.

[0123] As shown in Figure 18, in Test Example 4, it was observed that at the first edge of the first etching pattern, the position of the second end was (3.2,145), the position of the second bottom was (5.4,113), the position of the first apex was (0,80), the position of the first bottom was (16.0,35), and the position of the first end was (9.4,0). Furthermore, at the second edge, it was observed that the position of the fourth end was (58.0,145), the position of the fourth bottom was (51.0,113), the position of the second apex was (58.1,80), the position of the third bottom was (50.1,33), and the position of the third end was (55.5,0).

[0124] The spring width was found to be 54.8 μm at the Y-coordinate of 145 μm, 42.4 μm at the Y-coordinate of 113 μm, 50.1 μm at the Y-coordinate of 80 μm, 34.1 μm at the Y-coordinate of 33 μm, and 46.1 μm at the Y-coordinate of 0 μm.

[0125] It was observed that the spring width had local minimums at positions where the Y-coordinate was 113 μm and 33 μm, and a local maximum at a position where the Y-coordinate was 80 μm.

[0126] Furthermore, at the first edge of the second etching pattern, it was observed that the position of the second end was (0,145), the position of the second bottom was (4.0,118), the position of the first apex was (0.9,84), the position of the first bottom was (13.6,34), and the position of the first end was (6.8,0). Additionally, at the second edge, it was observed that the position of the fourth end was (50.3,145), the position of the fourth bottom was (40.5,106), the position of the second apex was (44.1,78), the position of the third bottom was (39.3,42), and the position of the third end was (50.5,0).

[0127] The spring width was found to be 50.3 μm at the Y-coordinate of 145 μm, 37.0 μm at the Y-coordinate of 110 μm, 43.1 μm at the Y-coordinate of 80 μm, 26.0 μm at the Y-coordinate of 39 μm, and 43.7 μm at the Y-coordinate of 0 μm.

[0128] It was found that the spring width had local minimums at positions where the Y coordinate was 110 μm and 39 μm, and a local maximum at a position where the Y coordinate was 80 μm.

[0129] Thus, in the first etching pattern of Test Example 4, it was observed that in the first direction D1, the amount by which the first vertex protrudes relative to the central axis of the etching pattern was greater than the amount by which each end protrudes relative to the central axis. Furthermore, it was observed that in the second etching pattern, the amount by which the second vertex protrudes relative to the central axis of the etching pattern was greater than the amount by which each end protrudes relative to the central axis. In addition, in the second etching pattern, it was observed that in the first direction D1, the amount by which the first vertex protrudes relative to the central axis of the etching pattern was 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 vertices come into contact with each other during operation, which increases the probability of damage to the spring member.

[0130] Referring to Figures 19 to 22, the results of the analysis of the etching patterns for each test example will be explained. In the following, the minimum value of the etching pattern width between the first end E1 and the first apex T1 will be referred to as the first minimum value, and the minimum value between the second end E2 and the first apex T1 will be referred to as the second minimum value.

[0131] Furthermore, in Figures 19 to 22, L1 is the first distance, T is the thickness of the etching pattern, and L2 is the second distance. Also, in Figures 19 to 22, Aw is the width of the etching pattern on the second surface 21S2, Bw is the second minimum value, Cw is the maximum value, Dw is the first minimum value, and Ew is the width of the etching pattern on the first surface 21S1.

[0132] As shown in Figure 19, in the first etching pattern of Test Example 1, the first distance, which is the distance between the maximum value in the Y coordinate and each position, was found to be 71 μm at 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, the percentage of each first distance relative to the thickness of the etching pattern was found to be 47.3% at the second surface 21S2, 22.0% at the second minimum value, 24.0% at the first minimum value, and 49.3% at the first surface 21S1. In addition, the second distance, which is the distance between the first and second minimum values ​​in the Y coordinate, was found to be 69 μm. Furthermore, the percentage of the second distance relative to the thickness of the etching pattern was found to be 46.0%.

[0133] In the first etching pattern, the percentage of the width at each position relative to the width on the second surface 21S2 was found to be 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. The percentage of the width at each position relative to the width on the first surface 21S1 was found to be 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. The percentage of the second minimum relative to the maximum was found to be 77.2%. The percentage of the first minimum relative to the maximum was found to be 69.4%.

[0134] In the second etching pattern of Test Example 1, the first distance was found to be 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, the percentage of each first distance relative to the thickness of the etching pattern was found to be 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. In addition, the second distance was found to be 67 μm. Furthermore, the percentage of the second distance relative to the thickness of the etching pattern was found to be 44.7%.

[0135] In the second etching pattern, the percentage of the width at each position relative to the width on the second surface 21S2 was found to be 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. The percentage of the width at each position relative to the width on the first surface 21S1 was found to be 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 was found to be 75.6%. The width at the first minimum relative to the maximum was found to be 72.0%.

[0136] As shown in Figure 20, in the first etching pattern of Test Example 2, the first distance was found to be 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, the percentage of each first distance relative to the thickness of the etching pattern was found to be 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. In addition, the second distance was found to be 59 μm. Furthermore, the percentage of the second distance relative to the thickness of the etching pattern was found to be 39.3%.

[0137] In the first etching pattern, the percentage of the width at each position relative to the width on the second surface 21S2 was found to be 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. The percentage of the width at each position relative to the width on the first surface 21S1 was found to be 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. The percentage of the width at the second minimum relative to the maximum was found to be 82.0%. The percentage of the width at the first minimum relative to the maximum was found to be 66.5%.

[0138] In the second etching pattern of Test Example 2, the first distance was found to be 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, the percentage of each first distance relative to the thickness of the etching pattern was found to be 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. In addition, the second distance was found to be 63 μm. Furthermore, the percentage of the second distance relative to the thickness of the etching pattern was found to be 42.0%.

[0139] In the second etching pattern, the percentage of the width at each position relative to the width on the second surface 21S2 was found to be 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. The percentage of the width at each position relative to the width on the first surface 21S1 was found to be 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. The percentage of the width at the second minimum relative to the maximum was found to be 68.9%. The percentage of the width at the first minimum relative to the maximum was found to be 82.6%.

[0140] As shown in Figure 21, in the first etching pattern of Test Example 3, the first distance was found to be 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, the percentage of each first distance relative to the thickness of the etching pattern was found to be 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. In addition, the second distance was found to be 72 μm. Furthermore, the percentage of the second distance relative to the thickness of the etching pattern was found to be 48.0%.

[0141] In the first etching pattern, the percentage of the width at each position relative to the width on the second surface 21S2 was found to be 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. The percentage of the width at each position relative to the width on the first surface 21S1 was found to be 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. The percentage of the width at the second minimum relative to the maximum was found to be 75.9%. The percentage of the width at the first minimum relative to the maximum was found to be 59.4%.

[0142] In the second etching pattern of Test Example 3, the first distance was found to be 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. The percentage of the first distance to the thickness of the etching pattern was found to be 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. The second distance was found to be 83 μm. The percentage of the second distance to the thickness of the etching pattern was found to be 55.3%.

[0143] In the second etching pattern, the percentage of the width at each position relative to the width on the second surface 21S2 was found to be 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 percentage of the width at each position relative to the width on the first surface 21S1 was found to be 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. The percentage of the width at the second minimum relative to the maximum was found to be 63.8%. The percentage of the width at the first minimum relative to the maximum was found to be 55.6%.

[0144] As shown in Figure 22, in the first etching pattern of Test Example 4, the first distance was found to be 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, the percentage of the first distance to the thickness of the etching pattern was found to be 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. Furthermore, the second distance was found to be 80 μm. Furthermore, the percentage of the second distance to the thickness of the etching pattern was found to be 58.3%.

[0145] In the first etching pattern, the percentage of the width at each position relative to the width on the second surface 21S2 was found to be 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. The percentage of the width at each position relative to the width on the first surface 21S1 was found to be 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. The percentage of the width at the second minimum relative to the maximum was found to be 75.9%. The percentage of the width at the first minimum relative to the maximum was found to be 59.4%.

[0146] In the second etching pattern of Test Example 4, the first distance was found to be 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, the percentage of the first distance to the thickness of the etching pattern was found to be 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. In addition, the second distance was found to be 71 μm. Furthermore, the percentage of the second distance to the thickness of the etching pattern was found to be 47.3%.

[0147] In the second etching pattern, the percentage of the width at each position relative to the width on the second surface 21S2 was found to be 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 position relative to the width on the first surface 21S1 was found to be 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. The percentage of the width at the second minimum relative to the maximum was found to be 63.8%. The percentage of the width at the first minimum relative to the maximum was found to be 55.6%.

[0148] In other words, in the etching patterns of Test Examples 1 and 2, both 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 were found to be 66% or higher. In contrast, in Test Examples 3 and 4, etching patterns were found to include at least one of the percentages of the first minimum value relative to the maximum value and the percentage of the second minimum value relative to the maximum value being less than 66%.

[0149] Furthermore, in the etching patterns of Test Examples 1 and 2, it was found that both the percentage of the first distance at the first minimum relative to the thickness of the etching pattern, and the percentage of the first distance at the second minimum relative to the thickness of the etching pattern, were 24% or less. In contrast, in Test Examples 3 and 4, it was found that the etching patterns included at least one of the percentages of the first distance at the first minimum relative to the thickness of the etching pattern, and the percentages of the first distance at the second minimum relative to the thickness of the etching pattern, were greater than 24%.

[0150] Furthermore, in the etching patterns of Test Examples 1 and 2, it was observed that the percentage of the second distance relative to the etching pattern fell within the range of 39% to 46%. In contrast, in the etching patterns of Test Examples 3 and 4, it was observed that the percentage of the second distance relative to the etching pattern exceeded 46%.

[0151] As described above, according to one embodiment of the spring member, the following effects can be obtained. (1) Since the first edge portion 13E1 of the inner spring 13A2 has a first bottom portion B1, a first top portion T1, and a second bottom portion B2, it is possible to reduce the amount of constriction at each bottom portion B1 and B2 compared to the case where the inner spring 13A2 is constricted at one point in the thickness direction. This makes it possible to improve the uniformity of the spring width in the thickness direction of the inner spring 13A2.

[0152] (2) In addition to the first edge portion 13E1, the second edge portion 13E2 may have a third bottom portion B3, a second top portion T2, and a fourth bottom portion B4. In this case, the uniformity of the spring width in the inner spring 13A2 can be further improved compared to the case where only the first edge portion 13E1 has two bottom portions and a top portion sandwiched between the two bottom portions.

[0153] (3) The inner spring 13A2 is likely to have a maximum value in spring width between the first peak T1 and the second peak T2 in the second direction D2. As a result, the inner spring 13A2 is unlikely to have a constricted shape at only one point in the thickness direction, and therefore the variation in spring width in the thickness direction of the inner spring 13A2 is suppressed.

[0154] (4) The width of the inner spring 13A2 may have a maximum value at the first peak T1 or the second peak T2. In this case, the inner spring 13A2 does not have a shape that is constricted at only one point in the thickness direction, so that variation in the spring width in the thickness direction of the inner spring 13A2 is suppressed.

[0155] (5) Even when a thick spring 13A having a thickness of 150 μm or more is manufactured by wet etching of metal foil 21, the difference between the minimum and maximum values ​​of the spring width in the thickness direction is suppressed.

[0156] (6) Near the spring 13A, in the first direction D1, the etching amount of the metal foil 21 becomes so large that more than half of the metal foil 21 is etched, so the constriction of the inner spring 13A2 tends to become more pronounced. Therefore, the effect of the inner spring 13A2 having the first edge portion 13E1 can be clearly obtained.

[0157] The above-described embodiment can be implemented with the following modifications. [First edge] The distance DT1 between the central axis 13AA and the first apex T1 may 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 effect similar to (1) described above can be obtained by having the first edge 13E1 have a first bottom B1, a first apex T1, and a second bottom B2.

[0158] [Second edge] The distance DT2 between the central axis 13AA and the second apex T2 may 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 effect similar to (2) described above can be obtained by having the second edge 13E2 have the third bottom B3, the second apex T2, and the fourth bottom B4.

[0159] [Internal spring] 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 effects similar to those described in (1) above can be obtained.

[0160] The second edge portion 13E2 may have a third bottom portion B3, a second top portion T2, and a fourth bottom portion B4, while the first edge portion 13E1 may not have a first bottom portion B1, a first top portion T1, and a second bottom portion B2. Even in this case, the effects similar to those described in (1) above can be obtained. [Explanation of Symbols]

[0161] 10... Spring component 11…Outer frame 12...Inner frame section 13... Spring part 13A1...Outer spring 13A2... Inner spring 13E1...1st edge 13E2…Second edge B1...1st bottom B2…Second bottom B3...Third bottom B4…4th bottom E1...first end E2…Second end E3...Third end E4...Fourth end T1...1st top T2…Second top

Claims

1. Page 1 and, The second surface is on the opposite side from the first surface, In a cross-section perpendicular to the first surface, the plurality of springs are arranged along a first direction, and each of these plurality of springs includes a pair of outer springs and an inner spring sandwiched between the outer springs in the first direction. The direction perpendicular to the first direction is the second direction. The inner spring comprises a first edge and a second edge facing 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 apex 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 apex 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 apex is longer than the distance between the central axis and the first bottom, and the distance between the central axis and the second bottom. Spring component.

2. The second edge includes 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 apex 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 vertex 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 apex is longer than the distance between the central axis and the third bottom, and the distance between the central axis and the fourth bottom. The spring member according to claim 1.

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

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

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

6. In the second direction, the width of the inner spring has a first minimum value between the first end and the first apex, and a second minimum value between the second end and the first apex. 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 66% or more. The spring member according to claim 5.

7. In the second direction, the width of the inner spring has a first minimum value between the first end and the first apex, and a second minimum value between the second end and the first apex. 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 24% or less. The spring member according to claim 5.

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

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

10. The pitch of the aforementioned plurality of springs is 100 μm or more and 200 μm or less. The maximum value in the width of each spring along the first direction is less than or equal to half the pitch. The spring member according to any one of claims 1 to 3.

11. The spring member comprises a base material selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium copper. The base material comprises 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. The spring member according to any one of claims 1 to 3.

12. The spring member is provided according to any one of claims 1 to 3. Camera module.

13. The camera module is provided according to claim 12. electronic equipment.

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