Spring components, camera modules, and electronic devices

Abstract

The present invention provides a spring member, a camera module, and electronic equipment that can suppress vibration disturbances and improve rigidity of the spring. [Solution] The spring member for the camera module has a first surface 10S1 and a second surface 10S2, and comprises a spring portion 13 including three or more thin wires 13A arranged along a first direction D1 in a cross section perpendicular to the first surface 10S1. The outer thin wire 13A1 has a first surface which is the side opposite to the side facing the inner thin wire 13A2, and the first surface has a shape that is symmetrical with respect to a straight line extending along the first direction D1 through the central part of the second direction D2 in the outer thin wire 13A1. The inner thin wire 13A2 has a side which faces the other thin wires and has an uneven shape.

Description

Technical Field

[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. As the drive mechanism, a lens drive method and a sensor drive method are known. 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. On the other hand, 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

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The spring member includes a spring portion formed of a metal foil. In order to obtain desired characteristics regarding the load and deflection of the spring portion, it is desired to solve problems such as suppression of vibration disturbance caused by external forces such as air resistance, suppression of vibration disturbance caused by vibration variation, suppression of breakage or disconnection of the spring portion due to stress concentration, and improvement of rigidity in a thin structure made of a metal foil.

Means for Solving the Problems

[0005] This document describes various embodiments of spring members, camera modules, and electronic devices that address the above-mentioned problems. [Aspect 1] A spring member for a camera module, comprising a spring portion having a first surface and a second surface opposite to the first surface, and including three or more thin wires arranged along a first direction in a cross section perpendicular to the first surface, wherein the direction perpendicular to the first direction in the cross section is the second direction, and in the arrangement of the thin wires, the thin wires located at both ends in the first direction are outer thin wires, the thin wire sandwiched between the outer thin wires is the inner thin wire, the outer thin wire has a first surface which is the side opposite to the side facing the inner thin wire, the first surface has a shape that is symmetrical in the cross section with respect to a straight line extending along the first direction through the central part of the outer thin wire in the second direction, and the inner thin wire has a side surface that is opposite to the other thin wires and has an uneven shape.

[0006] With the above configuration, air resistance acting on the outermost nanowire located at the outermost part of the spring is suppressed in a direction different from the direction of vibration, and vibration variation is reduced, thereby suppressing vibration disturbance. Furthermore, the rigidity of the inner nanowire is increased, which suppresses breakage and disconnection of the inner nanowire.

[0007] [Aspect 2] A spring member for a camera module, comprising a spring portion having a first surface and a second surface opposite to the first surface, and including three or more thin wires arranged along a first direction in a cross section perpendicular to the first surface, wherein the direction perpendicular to the first direction in the cross section is the second direction, and in the arrangement of the thin wires, the thin wires located at both ends in the first direction are outer thin wires, the thin wire sandwiched between the outer thin wires are inner thin wires, the outer thin wire has a first surface which is the side opposite to the side facing the inner thin wire, the center line is a straight line passing through the center position in the first direction of the outer thin wire in the cross section, the length along the first direction from the first surface to the center line decreases from both ends in the second direction of the outer thin wire toward the center, and the inner thin wire has a side surface with an uneven shape that faces the other thin wires.

[0008] With the above configuration, air resistance acting on the outermost nanowire located at the outermost part of the spring is suppressed in a direction different from the direction of vibration, and vibration variation is reduced, thereby suppressing vibration disturbance. Furthermore, the rigidity of the inner nanowire is increased, which suppresses breakage and disconnection of the inner nanowire.

[0009] [Aspect 3] The spring member according to [Aspect 1] or [Aspect 2], wherein in the cross-section, the straight line passing through the center position in the first direction of the outer thin wire is the center line, and the length along the first direction from the first side surface to the center line is smallest at the center in the second direction. With the above configuration, the outer thin wires can more easily capture air in the central part of the second direction, making it easier for vibrations along the vibration direction to occur appropriately.

[0010] [Aspect 4] The spring member according to any one of [Aspect 1] to [Aspect 3], wherein in the cross-section, a straight line passing through the center position in the first direction of the outer thin wire is the center line, and the first side surface has an arc shape that is recessed toward the center line. With the above configuration, the outer thin wires can more easily capture air in the central part of the second direction, making it easier for vibrations along the vibration direction to occur appropriately.

[0011] [Aspect 5] The spring member according to any one of [Aspect 1] to [Aspect 4], wherein the side surface of the outer thin wire facing the inner thin wire is a second side surface, and the second side surface has an uneven shape. The above configuration allows for increased rigidity of the outer thin wires.

[0012] [Aspect 6] The spring member according to any one of [Aspect 1] to [Aspect 5], wherein the centroid of the outer thin wire in the cross-section is located in the central part of the outer thin wire in the second direction. According to the above configuration, the oscillation of the outer nanowire in a direction different from the vibration direction is suppressed, and vibration variation is also reduced. Therefore, it is possible to suppress the occurrence of vibration disturbances.

[0013] [Aspect 7] The spring member according to any one of [Aspect 1] to [Aspect 6], wherein the outer nanowires located at both ends in the first direction have a first side surface which is the same shape as the first side surface which is the same as the other outer nanowire, but in the first direction. With the above configuration, vibrations tend to become more uniform.

[0014] [Aspect 8] In the cross-section, the uneven shape of the side surface of the inner thin wire includes three or more bending points, as described in any one of [Aspect 1] to [Aspect 7]. The above configuration allows for increased rigidity of the inner thin wire.

[0015] [Aspect 9] The spring member according to [Aspect 5], wherein the uneven shape of the second side surface of the outer thin wire in the cross-section includes three or more bending points. The above configuration allows for increased rigidity of the outer thin wires.

[0016] [Aspect 10] The spring member according to any one of [Aspect 1] to [Aspect 9], wherein the side surface of the outer thin wire facing the inner thin wire is the second side surface, and in the cross-section, the straight line passing through the center position in the first direction of the outer thin wire is the center line, and the position in the second direction of the point where the length along the first direction from the first side surface to the center line is smallest and the position where the length along the first direction from the second side surface to the center line is smallest are different from each other. According to the above configuration, localized thinning of the outer nanowire is suppressed, and fracture or breakage of the outer nanowire due to stress concentration is also suppressed. Therefore, the strength of the outer nanowire is increased.

[0017] [Aspect 11] The spring member according to any one of [Aspect 1] to [Aspect 10], wherein the spring member is selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium copper. According to the above configuration, since a high hardness can be obtained for the spring member, it is possible to enhance the durability of the spring member.

[0018] [Aspect 12] 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, and a copper layer located on at least one of the two surfaces of the base material. The spring member according to any one of [Aspect 1] to [Aspect 11].

[0019] According to the above configuration, since a high hardness can be obtained for the spring member, it is possible to enhance the durability of the spring member.

[0020] [Aspect 13] A camera module including the spring member according to any one of [Aspect 1] to [Aspect 12]. According to the above configuration, it is possible to suppress vibration disturbance and realize a camera module provided with a spring member having enhanced rigidity. Therefore, it is possible to improve the quality of the camera module.

[0021] [Aspect 14] An electronic device including the camera module according to [Aspect 13]. According to the above configuration, it is possible to suppress vibration disturbance and realize an electronic device provided with a spring member having enhanced rigidity in the camera module. Therefore, it is possible to improve the quality of the electronic device. [Advantages of the Invention]

[0022] According to the present disclosure, in the spring member, it is possible to solve problems including suppression of disturbance of spring vibration and improvement of rigidity. [Brief Description of the Drawings]

[0023] [Figure 1] FIG. 1 is a plan view showing the structure of the spring member. [Figure 2] FIG. 2 is a cross-sectional view showing the structure along the line II-II of FIG. 1. [Figure 3]Figure 3 is a cross-sectional view showing the structure of the outer nanowire. [Figure 4] Figure 4 is a cross-sectional view showing the structure of the inner nanowire. [Figure 5] Figure 5 shows the effect of air resistance on the outer thin wire. [Figure 6] Figure 6 shows the effect of air resistance on the outer nanowire. [Figure 7] Figure 7 is a process diagram showing one step in the manufacturing method of a spring member. [Figure 8] Figure 8 is a process diagram showing one step in the manufacturing method of a spring member. [Figure 9] Figure 9 is a process diagram showing one step in the manufacturing method of a spring member. [Figure 10] Figure 10 is a process diagram showing one step in the manufacturing method of a spring member. [Figure 11] Figure 11 is a process diagram showing one step in the manufacturing method of a spring member. [Figure 12] Figure 12 is a table showing the measurement results of the width of the thin wires in the spring member of the embodiment. [Modes for carrying out the invention]

[0024] An embodiment of a spring member, a camera module, and an electronic device will be described with reference to the drawings. [Spring component] The overall configuration of the spring member used in the camera module will be explained with reference to Figures 1 and 2. Figure 1 schematically shows the planar structure of the spring member as viewed from a viewpoint opposite to the plane in which the spring member extends.

[0025] As shown in Figure 1, the spring member 10 has a first surface 10S1 and a second surface 10S2 opposite to the first surface 10S1. The first surface 10S1 is located at one end of the spring member 10 in the thickness direction, and the second surface 10S2 is located at the other end of the spring member 10 in the thickness direction. The spring member 10 comprises an outer frame portion 11, an inner frame portion 12, and a spring portion 13. The spring portion 13 is a leaf spring.

[0026] 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 inner frame portion 12 is located within the area defined by the outer frame portion 11. The spring portion 13 connects the inner frame portion 12 to the outer frame portion 11. The 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.

[0027] The spring portion 13 comprises a plurality of thin wires 13A. When viewed from a viewpoint opposite to the plane on which the spring member 10 expands, each thin wire 13A has a straight shape extending along the plane on which the spring member 10 expands, and a plurality of thin wires 13A are arranged in parallel. Each thin wire 13A is part of the metal foil that forms the spring member 10.

[0028] The spring portion 13 may have a structure in which a single wire has multiple bends, making it appear as if multiple thin wires 13A are lined up, or it may have multiple thin wires 13A that are independent of each other and lined up. In the example shown in Figure 1, adjacent thin wires 13A are connected to each other by bends.

[0029] In a lens-driven drive 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 relative to the outer frame 11 in each spring member 10, the position of the lens changes. This makes it possible to correct camera shake using a lens-driven drive 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 relative to the outer frame 11 in each spring member 10, the position of the image sensor 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 in the thickness direction along the line II-II shown in Figure 1. That is, the cross-sectional structure shown in Figure 2 is the cross-sectional structure of the spring portion 13 along a plane that is perpendicular to the first surface 10S1 of the spring member 10 and perpendicular to the direction in which each thin wire 13A extends.

[0033] As shown in Figure 2, in a cross-section perpendicular to the first surface 10S1, the spring portion 13 contains three or more thin wires 13A. The direction in which the thin wires 13A are aligned is the first direction D1. The multiple thin wires 13A are arranged at approximately equal intervals in the first direction D1. Of the multiple thin wires 13A, the thin wires 13A located at both ends in the first direction D1 are the outer thin wires 13A1. Of the multiple thin wires 13A, the thin wire 13A sandwiched between the outer thin wires 13A1 in the first direction D1 is the inner thin wire 13A2. Furthermore, the thickness direction of the spring portion 13 is the second direction D2, and the second direction D2 is perpendicular to the first direction.

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

[0035] In each of the multiple thin wires 13A, including the outer thin wire 13A1 and the inner thin wire 13A2, the width on the first surface 10S1 is the first width WS1, and the width on the second surface 10S2 is the second width WS2.

[0036] The first width WS1 and the second width WS2 of the thin wire 13A may each be 10 μm or more. If the first width WS1 and the second width WS2 of the thin wire 13A are each 10 μm or more, it is possible to suppress the excessive influence of air resistance in various directions on the thin wire 13A. Regarding the upper limit of the first width WS1 and the second width WS2 of the thin wire 13A, each may be 40 μm or less, 20 μm or less, or 15 μm or less. If the first width WS1 and the second width WS2 of the thin wire 13A are each below the above upper limit, it is possible to secure the driving area of ​​the spring portion 13 within a limited space and to easily adjust the drive. In each thin wire 13A, the first width WS1 and the second width WS2 may be the same as or different from each other.

[0037] The width of the outer thin wire 13A1 may be the same as or different from the width of the inner thin wire 13A2 on each of the first surface 10S1 and the second surface 10S2. For example, the outer thin wire 13A1 may have a wider width than the inner thin wire 13A2 on each of the first surface 10S1 and the second surface 10S2.

[0038] In the first direction D1, the distance between the centers of adjacent thin wires 13A is the pitch P of the arrangement of thin wires 13A. The pitch P may be the distance between the centers of thin wires 13A on the first surface 10S1, or the distance between the centers of thin wires 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 500 μm.

[0039] The thickness of the spring member 10 may be between 100 μm and 200 μm. The thickness of the spring member 10 is the distance between the first surface 10S1 and the second surface 10S2. That is, the length of the thin wire 13A along the second direction D2 may be between 100 μm and 200 μm.

[0040] The spring member 10 is made of a metal having high hardness to the extent that it can achieve the required spring load or deflection of the spring portion 13. The spring member 10 may be made of, 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".

[0041] 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. This allows the spring member 10 to have high hardness, thereby increasing its durability.

[0042] Furthermore, the spring member 10 may comprise a base material made of metal 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 copper layer may be located on at least one of two surfaces in the thickness direction of the base material. That is, the base material comprises a first surface and a second surface opposite to the first surface, and the copper layer may cover both the first and second surfaces, or cover only the first surface or only the second surface. The copper layer is formed on the base material using methods such as vacuum deposition, sputtering, and wet plating.

[0043] [Outer thin line] The structure of the outer nanowire 13A1 will be described in detail with reference to Figure 3. As shown in Figure 3, in the outer thin wire 13A1, the side located at one end of the first direction D1 is the first side surface 14S1, and the side located at the other end of the first direction D1 is the second side surface 14S2. Of these, the second side surface 14S2 is the surface facing the inner thin wire 13A2. The first side surface 14S1 is the surface facing the opposite side from the inner thin wire 13A2, and is the outermost surface in the first direction D1 among the group of thin wires 13A constituting the spring portion 13. In other words, the outer thin wire 13A1 has a side adjacent to the inner thin wire 13A2 on the second side surface 14S2, but does not have any thin wires 13A adjacent to the first side surface 14S1.

[0044] The first side surface 14S1 satisfies at least one of the following conditions 1 and 2 in a cross section perpendicular to the first surface 10S1, i.e., a cross section along the first direction D1 and the second direction D2.

[0045] (Condition 1) The axis X1 is a hypothetical straight line that extends along the first direction D1 through the central part of the second direction D2 in the outer thin line 13A1, and the first side surface 14S1 has a shape that is symmetrical with respect to the axis X1.

[0046] (Condition 2) The center line X2 is a hypothetical straight line that extends along the second direction D2 through the center position of the first direction D1 in the outer thin line 13A1, and the length along the first direction D1 from the first side surface 14S1 to the center line X2 decreases from both ends to the center in the second direction D2.

[0047] The details of Condition 1 and Condition 2 will be explained in order. First, the axis X1 and centerline X2 used as references in Condition 1 and Condition 2 will be explained. The axis X1 extending in the first direction D1 passes through the center of the outer nanowire 13A1 in the second direction D2. The center of the outer nanowire 13A1 in the second direction D2 is the region in the second direction D2 where the distance from the center position of the outer nanowire 13A1 is within 10% of the total length of the outer nanowire 13A1. Here, the center position of the outer nanowire 13A1 in the second direction D2 is the position where the length to the first surface 10S1 in the second direction D2 is equal to the length to the second surface 10S2. The total length of the outer nanowire 13A1 is the thickness of the outer nanowire 13A1, that is, the length along the second direction D2 between the first surface 10S1 and the second surface 10S2 of the outer nanowire 13A1.

[0048] Furthermore, it is preferable that the axis X1 passes through a central range within the central part of the outer thin wire 13A1 in the second direction D2, where the distance from the center position of the outer thin wire 13A1 in the second direction D2 is within 5% of the total length of the outer thin wire 13A1. Figure 3 shows an example in which the axis X1 passes through the center position of the outer thin wire 13A1 in the second direction D2.

[0049] The center line X2 extending in the second direction D2 passes through the center position of the outer thin line 13A1 in the first direction D1. The center position of the outer thin line 13A1 in the first direction D1 is the position where the length along the first direction D1 to each of the ends of the outer thin line 13A1 in the first direction D1 is equal. That is, this position is the position where the length along the first direction D1 from the outermost point in the first direction D1 within the first side surface 14S1 is equal to the length along the first direction D1 from the outermost point in the first direction D1 within the second side surface 14S2.

[0050] The point located furthest out in the first direction D1 on each side 14S1, 14S2 is, in other words, the point that protrudes the most in the first direction D1 and is the point furthest from the center line X2. The point located furthest out in the first direction D1 on each side 14S1, 14S2 may be a point included in the first surface 10S1 or the second surface 10S2.

[0051] Condition 1 will now be explained. The first side surface 14S1 has a shape that is symmetrical with respect to axis X1. In this embodiment, a shape that is symmetrical with respect to axis X1 means a shape in which the difference in length along the first direction D1 from a reference point (which is any point on the first side surface 14S1) to the center line X2 between the reference point and a corresponding point across axis X1 is within 10% of the length along the first direction D1 from the reference point to the center line X2.

[0052] A point corresponding to the reference point across axis X1 is a point on the first surface 14S1 whose length along the second direction D2 to axis X1 is equal to that of the reference point. Figure 3 illustrates the reference point P1 and the corresponding point P2. The difference between the length L1 along the first direction D1 from point P1 to centerline X2 and the length L2 along the first direction D1 from point P2 to centerline X2 is within 10% of length L1.

[0053] When condition 1 is met, the first side surface 14S1 may have an uneven shape. The first side surface 14S1 may have one inflection point or multiple inflection points. The first side surface 14S1 may include one or more recesses, one or more protrusions, or one or more recesses and one or more protrusions.

[0054] Condition 2 is explained below. The length L along the first direction D1 from the first side surface 14S1 to the center line X2 decreases from each of the ends of the second direction D2 in the outer nanowire 13A1 toward the center of the second direction D2. The ends of the second direction D2 are the first surface 10S1 and the second surface 10S2. The center of the second direction D2 is, as described above, the region in the second direction D2 where the distance from the center position of the outer nanowire 13A1 is within 10% of the total length of the outer nanowire 13A1.

[0055] In other words, the length L is largest at the end of the first surface 14S1 included in the first surface 10S1 or the second surface 10S2, and smallest in the central part of the second direction D2. Furthermore, it is preferable that the length L is smallest in the central range of the second direction D2 in the outer thin wire 13A1 described above. The length L may decrease monotonically from the end of the second direction D2 toward the position where the length L is smallest in the central part. When condition 2 is met, the first surface 14S1 has a concave shape that is recessed toward the center line X2.

[0056] The function of the shape of the first side surface 14S1 will be explained with reference to Figures 5 and 6. Figure 5 shows the force F due to air resistance experienced by the outer thin wire 13A1 at the first side surface 14S1 in this embodiment, and Figure 6 shows the force F due to air resistance experienced by the outer thin wire 100 at the first side surface 101 in a comparative example.

[0057] As shown in Figure 5, if the first side surface 14S1 satisfies at least one of conditions 1 and 2, then the first side surface 14S1 has a substantially symmetrical shape, with respect to the center position of the second direction D2, the first portion R1 which is the part on the side where the first surface 10S1 is located and the second portion R2 which is the part on the side where the second surface 10S2 is located. As a result, the component of force F acting in the second direction D2 cancels each other out, thus suppressing the air resistance acting in a direction different from the first direction D1, which is the vibration direction of the spring portion 13.

[0058] On the other hand, as shown in Figure 6, if the shapes of the first part R1 and the second part R2 are significantly different from symmetrical, the component of the force F in the second direction D2 will not cancel out, resulting in a large air resistance acting in a direction different from the vibration direction. As a result, disturbances are more likely to occur in the vibration trajectory and displacement of the spring.

[0059] In the case of the outer thin wire 13A1 of this embodiment shown in Figure 5, as described above, the air resistance acting in a direction different from the vibration direction is suppressed, thereby suppressing vibration disturbance. Furthermore, since the first part R1 and the second part R2 are substantially symmetrical, vibration variation is also suppressed, which in turn suppresses vibration disturbance.

[0060] The following configuration is common to the first side surface 14S1 in a cross-section perpendicular to the first surface 10S1, regardless of whether condition 1 or condition 2 is met. The length L along the first direction D1 from the first side surface 14S1 to the center line X2 is preferably smallest at the center of the second direction D2 described above in the outer thin wire 13A1, and more preferably smallest in the central range of the second direction D2 described above in the outer thin wire 13A1. With this configuration, air is more easily captured at the center of the second direction D2, so that vibrations along the vibration direction are more easily generated appropriately. From the viewpoint of enhancing this effect, it is preferable that the length L is maximum at the end of the second direction D2 where the first surface 10S1 or the second surface 10S2 is located.

[0061] The first side surface 14S1 may be a folded line composed of multiple line segments, a curved shape, or a combination of line segments and curves. If the first side surface 14S1 has an arc shape that curves inward toward the center line X2, it becomes easier to capture air in the central part of the second direction D2, thus making it easier for vibrations along the vibration direction to occur appropriately.

[0062] The centroid of the outer nanowire 13A1 in a cross-section perpendicular to the first surface 10S1 is preferably located within the central part of the second direction D2 described above in the outer nanowire 13A1, and more preferably within the central range of the second direction D2 described above in the outer nanowire 13A1. With this configuration, when subjected to an external force, the oscillation of the outer nanowire 13A1 in a direction different from the vibration direction is suppressed, and vibration variation is also reduced, thereby suppressing the occurrence of vibration disturbance.

[0063] The second side surface 14S2 of the outer thin wire 13A1 may have a shape that is the inverse of the first side surface 14S1 in the first direction D1, or it may have a shape different from such a shape. Preferably, the second side surface 14S2 satisfies the conditions corresponding to condition 3 described later, similar to the side surface of the inner thin wire 13A2.

[0064] It is preferable that the location in the second direction D2 where the length along the first direction D1 from the first side surface 14S1 to the center line X2 is smallest and the location in the second side surface 14S2 to the center line X2 is smallest are different from each other. In other words, it is preferable that the location on the first side surface 14S1 that is most recessed toward the center line X2 and the location on the second side surface 14S2 that is most recessed toward the center line X2 are offset in the second direction D2. With this configuration, local thinning of the outer thin wire 13A1 is suppressed, and fracture or breakage of the outer thin wire 13A1 due to stress concentration is suppressed, thereby increasing the strength of the outer thin wire 13A1.

[0065] The width of the outer thinnest wire 13A1, i.e., the length of the outer thinnest wire 13A1 along the first direction D1, may be greatest at the end in the second direction D2 where the first surface 10S1 or the second surface 10S2 is located. In other words, the width of the outer thinnest wire 13A1 on the first surface 10S1 and the width of the outer thinnest wire 13A1 on the second surface 10S2 may each be greater than the width of the region between the first surface 10S1 and the second surface 10S2.

[0066] The two outer thin wires 13A1 located at both ends of the first direction D1 may have shapes that are inverted from each other in the first direction D1, or they may have shapes that are different from these shapes. Preferably, the first side surface 14S1 of one of the two outer thin wires 13A1 has a shape that is inverted from the first side surface 14S1 of the other outer thin wire 13A1 in the first direction D1. The shape that is inverted in the first direction D1 means a shape in which the difference between the reference length, which is the length along the first direction D1 from an arbitrary reference point on the first side surface 14S1 of one outer thin wire 13A1 to the center line X2, and the length along the first direction D1 from a corresponding point on the first side surface 14S1 of the other outer thin wire 13A1 to the center line X2, is within 10% of the reference length. The corresponding point is the point where the position of the reference point and the position of the second direction D2 coincide.

[0067] With this configuration, since the sides located at both ends in the direction of vibration of the multiple thin wires 13A have similar shapes, the vibrational motion, i.e., the reciprocating motion along a predetermined trajectory, tends to become uniform.

[0068] [Inner thin line] Refer to Figure 4 to describe in detail the structure of the inner thin wire 13A2. As shown in Figure 4, in the inner thin wire 13A2, the side located at one end of the first direction D1 is the first side 15S1, and the side located at the other end of the first direction D1 is the second side 15S2. The inner thin wire 13A2 may be adjacent to the outer thin wire 13A1 or to another inner thin wire 13A2 at the first side 15S1. The inner thin wire 13A2 may be adjacent to the outer thin wire 13A1 or to another inner thin wire 13A2 at the second side 15S2.

[0069] Each of the first side surface 15S1 and the second side surface 15S2 satisfies the following condition 3 in a cross-section perpendicular to the first surface 10S1. (Condition 3) Side surfaces 15S1 and 15S2 have an uneven shape.

[0070] Condition 3 will be explained in detail. An uneven shape is a shape having one or more inflection points. An inflection point may be a connection point between straight line segments, or it may be a part that bends with curvature. An uneven shape may include one or more recesses, one or more convex parts, or one or more recesses and one or more convex parts.

[0071] When the side surfaces 15S1 and 15S2 have an uneven shape in cross-section, the second moment of area is more easily increased even with the same cross-sectional area compared to a configuration where the side surfaces 15S1 and 15S2 are straight and the inner thin wire 13A2 has a rectangular cross-section. Therefore, the rigidity of the inner thin wire 13A2 is increased.

[0072] The uneven shape of the sides 15S1 and 15S2 preferably has three or more inflection points. This can further increase the rigidity of the inner thin wire 13A2. Figure 4 shows an example in which the uneven shape has three inflection points. As shown in Figure 4, the sides 15S1 and 15S2 may have a shape in which one convex part is sandwiched between two concave parts in the second direction D2, or in other words, each has a shape in which a bending point located at the top of a convex part is sandwiched between two inflection points located at the bottom of a concave part. With such a shape, the rigidity of the inner thin wire 13A2 can be increased while preventing the sides 15S1 and 15S2 from becoming excessively complex, thus making the manufacturing of the inner thin wire 13A2 easier.

[0073] The sides 15S1 and 15S2 may be a folded line composed of multiple line segments, a curved line, or a combination of line segments and curves. Each of the first side 15S1 and the second side 15S2 may have a shape that is symmetrical with respect to a hypothetical straight line that extends along the first direction D1 through the center of the second direction D2 in the inner thin line 13A2. The first side 15S1 may also have a shape that is an inversion of the second side 15S2 in the first direction D1. Preferably, the centroid of the inner thin line 13A2 in a cross section perpendicular to the first surface 10S1 is included in the center of the second direction D2 in the inner thin line 13A2.

[0074] The width of the inner thin wire 13A2, i.e., the length of the inner thin wire 13A2 along the first direction D1, may be maximum at the end in the second direction D2 where the first surface 10S1 or the second surface 10S2 is located. In other words, the width of the inner thin wire 13A2 on the first surface 10S1 and the width of the inner thin wire 13A2 on the second surface 10S2 may each be greater than the width of the region between the first surface 10S1 and the second surface 10S2. If the spring portion 13 includes multiple inner thin wires 13A2, these inner thin wires 13A2 may have the same shape or may have different shapes from each other.

[0075] As described above, the second side surface 14S2 of the outer thin wire 13A1 preferably has an uneven shape, similar to condition 3. This uneven shape may have the same characteristics as the uneven shapes of the sides 15S1 and 15S2 of the inner thin wire 13A2. This can increase the rigidity of the outer thin wire 13A1. From the viewpoint of increasing the rigidity of the outer thin wire 13A1, it is preferable that in the second direction D2, a convex portion is located on the second side surface 14S2 in the same place where a concave portion is located on the first side surface 14S1.

[0076] Furthermore, by having the first side surface 14S1 and the second side surface 14S2 of the outer nanowire 13A1 have different shapes, the outer nanowire 13A1 can be configured so that the function of suppressing vibration disturbance due to the shape of the first side surface 14S1 and the function of increasing rigidity due to the shape of the second side surface 14S2 are appropriately performed.

[0077] [Method for manufacturing spring components] The manufacturing method of the spring member 10 will be explained with reference to Figures 7 to 11. As shown in Figure 7, when manufacturing the spring member 10, first a first resist layer PR1 is formed on the first surface 21S1 of the metal foil 21, and a second resist layer PR2 is formed on the second surface 21S2. In the example explained using Figures 7 to 11, each resist layer PR1 and PR2 is formed from a positive-type photoresist, but each resist layer PR1 and PR2 may be formed from a negative-type photoresist.

[0078] Next, as shown in Figure 8, the first photomask PM1 is placed on the first resist layer PR1, and the second photomask PM2 is placed on the second resist layer PR2. Then, the first resist layer PR1 is exposed using the first photomask PM1, and the second resist layer PR2 is exposed using the second photomask PM2.

[0079] As shown in Figure 9, the exposed resist layers PR1 and PR2 are developed to form the first resist mask RM1 from the first resist layer PR1 and the second resist mask RM2 from the second resist layer PR2.

[0080] As shown in Figure 10, the metal foil 21 is wet-etched using resist masks RM1 and RM2. During this process, the metal foil 21 is etched from both the first surface 21S1 and the second surface 21S2. This creates through-holes in the metal foil 21 that penetrate along the thickness direction, resulting in the formation of an outer frame portion 11, an inner frame portion 12 separated from the outer frame portion 11, and a spring portion 13 connecting the inner frame portion 12 to the outer frame portion 11.

[0081] As shown in Figure 11, after removing the resist masks RM1 and RM2 from the etched metal foil 21, the spring member 10 can be obtained by cutting it out from the etched metal foil 21.

[0082] The metal foil 21 for forming the spring member 10 may be the base material described above, or a laminate of the base material and a copper layer. The outer fine wire 13A1 is adjacent to the inner fine wire 13A2 on the second side surface 14S2, but does not have a fine wire 13A adjacent to the first side surface 14S1. Therefore, during wet etching of the metal foil 21, the first side surface 14S1 of the outer fine wire 13A1 comes into contact with more etching solution than the second side surface 14S2. Furthermore, the first side surface 14S1 is formed by an etching solution with a different flow than the etching solution used to form the second side surface 14S2. This makes it possible to form the outer fine wire 13A1 such that the first side surface 14S1 and the second side surface 14S2 have different shapes from each other.

[0083] Furthermore, the inner fine wire 13A2 is adjacent to other fine wires 13A on both sides in the first direction D1, and the distance between the fine wires 13A is approximately the same. Therefore, during wet etching of the metal foil 21, the sides 15S1 and 15S2 of the inner fine wire 13A2 are formed by etching solution with approximately the same amount and flow. As a result, the inner fine wire 13A2 can be formed such that the sides 15S1 and 15S2 have shapes that are inverted from each other in the first direction D1.

[0084] [Examples] The spring member 10 described above will be explained using a specific example. (Examples 1-1 to 1-8) A metal foil 21, made of titanium copper and having a thickness of 120 μm, was prepared. Next, resist masks RM1 and RM2 were formed on the first surface 21S1 and the second surface 21S2 of the metal foil 21, and the metal foil 21 was wet-etched from both the first surface 21S1 and the second surface 21S2 using the two resist masks RM1 and RM2. A ferric chloride aqueous solution was used as the etching solution during wet etching.

[0085] Furthermore, within a 280 mm square area of ​​the metal foil 21, unit areas corresponding to one spring member 10 and having a 20 mm square shape were arranged in a grid pattern so that they could be tiled in both the rolling direction and the width direction of the metal foil 21. Accordingly, each resist mask RM1 and RM2 also had a unit pattern corresponding to the shape of one spring member 10 arranged in a grid pattern so that it could be tiled in both the rolling direction and the width direction.

[0086] In the portion of the unit pattern corresponding to the spring portion 13, strip-shaped openings are arranged at intervals along one direction. The openings at both ends are first openings, and the opening sandwiched between the two first openings is a second opening. In the metal foil 21, the portion covered in the area between the first and second openings becomes an outer fine line 13A1, and the portion covered in the area between adjacent second openings becomes an inner fine line 13A2. The unit pattern was formed such that six fine lines 13A are formed, consisting of two outer fine lines 13A1 and four inner fine lines 13A2.

[0087] The width of the first aperture is 220 μm or less, and the width of the second aperture is 100 μm or less. The pitch of the aperture arrangement is 240 μm. Spring members of Examples 1-1 to 1-8 were obtained by using a unit pattern in which at least one of the widths of the first opening and the second opening was changed. Changing the width of the first opening changes the width of the region between the first and second openings, and changing the width of the second opening changes the width of the region between adjacent second openings. In Examples 1-1 to 1-4, the width of the second opening was kept constant, and the width of the first opening was changed. In Examples 1-5 to 1-8, the widths of the first and second openings were made smaller than in Example 1-1, and the width of the second opening was kept constant, while the width of the first opening was changed.

[0088] (Examples 2-1 to 2-8) Spring members of Examples 2-1 to 2-8 were obtained by using a unit pattern in which the thickness of the metal foil 21 was changed to 150 μm and at least one of the widths of the first and second openings was changed, and otherwise by the same method as in Examples 1-1 to 1-8. The pitch of the opening arrangement was 300 μm. In Examples 2-1 to 2-4, the width of the second opening was kept constant and the width of the first opening was changed. In Examples 2-5 to 2-8, the widths of the first and second openings were made smaller than in Example 2-1, and the width of the second opening was kept constant and the width of the first opening was changed.

[0089] (Examples 3-1 to 3-8) Spring members of Examples 3-1 to 3-8 were obtained by using a unit pattern in which the thickness of the metal foil 21 was changed to 200 μm and at least one of the widths of the first and second openings was changed, and otherwise by the same method as in Examples 1-1 to 1-8. The pitch of the opening arrangement was 400 μm. In Examples 3-1 to 3-4, the width of the second opening was kept constant and the width of the first opening was changed. In Examples 3-5 to 3-8, the widths of the first and second openings were made smaller than in Example 3-1, and the width of the second opening was kept constant and the width of the first opening was changed.

[0090] (Width of thin lines) The spring portion 13 contained in each metal foil 21 after etching was embedded using synthetic resin. Then, by cutting the embedded spring portion 13 using a microtome, the cross-section of the spring portion 13 in a plane perpendicular to the direction in which the fine wire 13A contained in the spring portion 13 extends, and perpendicular to the first surface 21S1, was exposed.

[0091] In the cross-section of the spring portion 13, the width of the thin wire 13A was measured at the following positions. Specifically, the width of the thin wire 13A was measured at the first width WS1 on the first surface 21S1 of the metal foil 21, the second width WS2 on the second surface 21S2 of the metal foil 21, and the width of the three planes between the first surface 21S1 and the second surface 21S2, which divide the spring portion 13 into four equal parts in the thickness direction. When measuring the width of the thin wire 13A, a digital microscope (VHX-6000, manufactured by Keyence Corporation) was used, and the magnification of the objective lens on the digital microscope was set to 100x.

[0092] In one spring section 13 of each metal foil 21, the average value of the first width WS1 was calculated from two outer thin wires 13A1 and from four inner thin wires 13A2. Then, for each of the outer thin wires 13A1 and inner thin wires 13A2, the average value of the first width WS1 in 10 spring sections 13 was averaged to calculate the average value of the first width WS1 of the outer thin wires 13A1 and the average value of the first width WS1 of the inner thin wires 13A2. These average values ​​were taken as the first width WS1 of the thin wires 13A1 and 13A2 in each embodiment.

[0093] Furthermore, in one spring portion 13 of each metal foil 21, the average value of the second width WS2 was calculated from two outer thin wires 13A1, and the average value of the second width WS2 was calculated from four inner thin wires 13A2. Then, for each of the outer thin wires 13A1 and inner thin wires 13A2, the average values ​​of the second width WS2 in 10 spring portions 13 were averaged to calculate the average values ​​of the second width WS2 for the outer thin wires 13A1 and the average values ​​of the second width WS2 for the inner thin wires 13A2. These average values ​​were used as the second width WS2 for the thin wires 13A1 and 13A2 in each embodiment.

[0094] Furthermore, in one spring section 13 of each metal foil 21, the average width of five points was calculated for each outer thin wire 13A1, and then the average width of two outer thin wires 13A1 was calculated. This allowed the average width of the outer thin wire 13A1 in one spring section 13 to be calculated. Then, by averaging the average widths of the outer thin wires 13A1 in 10 spring sections 13, the average width of the outer thin wires 13A1 was calculated. Furthermore, in one spring section 13 of each metal foil 21, the average width of five points was calculated for each inner thin wire 13A2, and then the average width of four inner thin wires 13A2 was calculated. This allowed the average width of the inner thin wires 13A2 in one spring section 13 to be calculated. Then, by averaging the average widths of the inner thin wires 13A2 in 10 spring sections 13, the average width of the inner thin wires 13A2 was calculated.

[0095] Figure 12 shows the average values ​​of the second width WS2 for the outer thin wire 13A1 and the inner thin wire 13A2 in each embodiment. In each thin wire 13A, the average value of the first width WS1 was found to be equivalent to the average value of the second width WS2. In addition, in each thin wire 13A, the width variation was found to be ±2 μm or less relative to the average width.

[0096] [Observation of the appearance of thin lines] For each embodiment, the shapes of the outer nanowire 13A1 and the inner nanowire 13A2 were observed using a digital microscope (VHX-6000, manufactured by Keyence Corporation).

[0097] As a result, for each of Examples 1-1 to 1-8, 2-1 to 2-8, and 3-1 to 3-8, the first side surface 14S1 of the outer thin wire 13A1 satisfied both conditions 1 and 2. In addition, the second side surface 14S2 of the outer thin wire 13A1 had an uneven shape. Furthermore, the first side surface 15S1 and the second side surface 15S2 of the inner thin wire 13A2 each satisfied condition 3.

[0098] As described above, the spring member, camera module, and electronic device of the above embodiments and examples can be used to obtain the following effects. (1) The first side surface 14S1 of the outer nanowire 13A1 satisfies at least one of conditions 1 and 2, and the first side surface 15S1 and the second side surface 15S2 of the inner nanowire 13A2 each satisfy condition 3. This suppresses the air resistance acting on the outer nanowire 13A1, which is located at the outermost part of the spring portion 13, in a direction different from the vibration direction, and reduces vibration variation, thereby suppressing vibration disturbance. Furthermore, the rigidity of the inner nanowire 13A2 is increased, thereby suppressing breakage and disconnection of the inner nanowire 13A2.

[0099] (2) In the outer thin wire 13A1, the length along the first direction D1 from the first side surface 14S1 to the center line X2 is smallest at the center of the second direction D2. With this configuration, the outer thin wire 13A1 can more easily capture air at the center of the second direction D2, so that vibrations along the vibration direction can be generated appropriately.

[0100] (3) In the outer thin wire 13A1, the first side surface 14S1 has an arc shape that is recessed toward the center line X2. With this configuration, the outer thin wire 13A1 can more easily capture air in the central part of the second direction D2, so that vibrations along the vibration direction can be generated appropriately.

[0101] (4) In the outer thin wire 13A1, the second side surface 14S2 has an uneven shape. With this configuration, the rigidity of the outer thin wire 13A1 can be increased. (5) The centroid of the outer nanowire 13A1 in the cross-section is located within the central part of the outer nanowire 13A1 in the second direction. With this configuration, the outer nanowire 13A1 is suppressed from oscillating in a direction different from the vibration direction, and vibration variation is also reduced, thereby suppressing the occurrence of vibration disturbances.

[0102] (6) In the outer nanowires 13A1 located at both ends in the first direction D1, the first side surface 14S1 of one outer nanowire 13A1 has a shape that is the inverse of the first side surface 14S1 of the other outer nanowire 13A1 in the first direction D1. With this configuration, vibration tends to become uniform.

[0103] (7) The uneven shape of the side surfaces 15S1 and 15S2 of the inner thin wire 13A2 includes three or more bending points. With this configuration, the rigidity of the inner thin wire 13A2 can be further increased. The uneven shape of the second side surface 14S2 of the outer thin wire 13A1 includes three or more bending points. With this configuration, the rigidity of the outer thin wire 13A1 can be further increased.

[0104] (8) In the outer thin wire 13A1, the location in the second direction D2 where the length along the first direction D1 from the first side surface 14S1 to the center line X2 is smallest and the location in the second direction D2 where the length along the first direction D1 from the second side surface 14S2 to the center line X2 is smallest are different from each other. With this configuration, local thinning of the outer thin wire 13A1 is suppressed, and fracture or breakage of the outer thin wire 13A1 due to stress concentration is suppressed, thereby increasing the strength of the outer thin wire 13A1.

[0105] (9) The spring member 10 includes one selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium copper. The spring member 10 includes a base material which includes one selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium copper, and a copper layer located on at least one of the two surfaces of the base material. With this configuration, high hardness can be obtained for the spring member 10, making it possible to increase the durability of the spring member 10. [Explanation of Symbols]

[0106] 10... Spring component 10S1…Side 1 10S2…Second side 13... Spring part 13A…Thin wire 13A1…Outer thin line 14S1…1st side 14S2…Second side 13A2…Inner thin line 15S1…First side 15S2…Second side

Claims

1. A spring component for a camera module, It has a first surface and a second surface opposite to the first surface, The spring portion includes three or more thin wires arranged along a first direction in a cross section perpendicular to the first surface, and the direction perpendicular to the first direction in the cross section is the second direction. In the arrangement of the thin lines, the thin lines located at both ends in the first direction are outer thin lines, and the thin lines sandwiched between the outer thin lines are inner thin lines. The centroid of the outer nanoline in the cross-section is located within the central part of the outer nanoline in the second direction. The inner fine wire has a side surface that has an uneven shape, facing the other fine wires. Spring component.

2. The outer thin wire has a first side surface which is the side surface opposite to the side surface facing the inner thin wire, In the cross-section, the straight line passing through the center position in the first direction of the outer thin line is the center line, and the length along the first direction from the first side surface to the center line is smallest at the center in the second direction. The spring member according to claim 1.

3. The outer thin wire has a first side surface which is the side surface opposite to the side surface facing the inner thin wire, In the cross-section, the straight line passing through the center position in the first direction of the outer thin line is the center line, and the first side surface has an arc shape that is recessed toward the center line. The spring member according to claim 1.

4. The side surface of the outer nanowire facing the inner nanowire is the second side surface, and the second side surface has an uneven shape. The spring member according to claim 1.

5. The outer thin wire has a first side surface which is the side surface opposite to the side surface facing the inner thin wire, In the outer nanowires located at both ends in the first direction, the first side surface of one of the outer nanowires has a shape that is the inverse of the first side surface of the other outer nanowire in the first direction. The spring member according to claim 1.

6. In the cross-section, the uneven shape of the side surface of the inner thin wire includes three or more bending points. The spring member according to claim 1.

7. In the cross-section, the uneven shape of the second side surface of the outer thin wire includes three or more bending points. The spring member according to claim 4.

8. The outer nanowire has a second side surface which is the side surface facing the inner nanowire, and a first side surface which is the side surface opposite to the second side surface. In the cross-section, the straight line passing through the center position in the first direction of the outer thin line is the center line, and the position in the second direction of the point where the length along the first direction from the first side surface to the center line is smallest and the position where the length along the first direction from the second side surface to the center line is smallest are different from each other. The spring member according to claim 1.

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

10. The spring member includes a base material selected from the group consisting of stainless steel alloy, beryllium copper, nickel-tin copper, phosphor bronze, Corson alloy, and titanium copper, and a copper layer located on at least one of the two surfaces of the base material. The spring member according to claim 1.

11. The spring member is provided according to any one of claims 1 to 10. Camera module.

12. The camera module is provided according to claim 11. electronic equipment.

Images