JP5997866B1 - Suspension wire - Google Patents

Abstract

A suspension wire 10 made of a Cu-15Ni-8Sn alloy, the outer diameter including the conductive plating layer 2 is in the range of 30 μm to 60 μm, the tensile strength is 1400 MPa or more, and the conductivity is 9% IACS or more. By adopting the suspension wire 10 within the range of 18% IACS or less, a thin and strong suspension wire having a short length and sufficient springiness can be provided. At this time, it is preferable that the conductive plating layer 2 is a silver plating layer, a copper plating layer, or a gold plating layer. [Selection] Figure 1

Description

  The present invention relates to a suspension wire that is preferably used in a camera shake correction device for a small camera or a thin camera.

  A suspension wire capable of buffering vibrations and shocks from the outside is known as being used for an optical pickup as shown in Patent Document 1, for example. This optical pickup is an assembly part including a laser light source and a light receiving part for reproducing and recording information from an optical disk when an optical disk medium such as a CD or a DVD is loaded in an optical disk drive or a player.

  Various suspension wires used for optical pickups have been proposed. For example, in Patent Document 2, a Cu—Ni—Sn alloy bus is pulled out by a multi-stage wire drawing machine, back tension is applied to travel in an electric furnace, and after aging treatment, tin plating is performed. Techniques for obtaining suspension wires have been proposed. This technique is said to be effective in that the reduction in tensile strength after solder immersion and the reduction in wire diameter due to solder erosion are small and can be manufactured at low cost.

  Suspension wires used for optical pickups are required to have strength and conductivity. For example, the suspension wire described in Patent Document 1 is made of a copper-silver alloy, the wire diameter is around 0.1 mm, and the wire diameter in the case of being made of a stranded wire is about 0.06 to 0.07 mm. . In addition, the tensile strength at this time is 800 MPa or more, preferably 900 MPa or more, and depending on the degree of processing, it is 1000 MPa or more, and the conductivity is 70% IACS to 80% IACS. Further, the suspension wire described in Patent Document 2 is made of a Cu—Ni—Sn-based alloy, and its wire diameter is about 0.1 mm, and a tensile strength of about 1380 MPa is obtained.

  In recent years, ultra-small camera modules are mounted particularly on small portable devices such as smartphones. When shooting with a small portable device having such a micro camera module, a camera shake correction function for correcting the lens position displaced by vibration is required. For example, Patent Document 3 proposes a camera shake correction apparatus that corrects camera shake (vibration) that occurs when a still image is captured with a small camera for a mobile phone so that an image without image blur can be captured. This technique has a problem of being small and low-profile. The solution is disclosed as follows. The entire auto-focus lens driving device or its movable part is arranged so that the lens barrel moves along the optical axis, and the focus coil is opposed to the focus coil and is radially outward of the focus coil with respect to the optical axis. And a permanent magnet. The entire autofocus lens driving device or its movable part moves the lens barrel in a first direction and a second direction orthogonal to the optical axis and orthogonal to each other. This is a camera shake correction apparatus that corrects camera shake. The camera shake correction device further includes: a base that is spaced apart from a bottom surface portion of the autofocus lens driving device; and a plurality of suspension wires each having one end fixed at an outer peripheral portion of the base. A plurality of suspension wires that extend along the autofocus lens and support the entire autofocus lens driving device or the movable portion thereof in a swingable manner in the first direction and the second direction; and the permanent magnet; It is characterized by having a camera-shake correction coil arranged oppositely.

JP 2003-168229 A Japanese Unexamined Patent Publication No. 2011-211984 JP 2011-65140 A

  In order to correct camera shake with the camera shake correction apparatus proposed in Patent Document 3, it is necessary to move a lens unit (hereinafter referred to as a movable portion) in a direction perpendicular to the optical axis. As a means for solving this, a suspension wire suspension system has been proposed in which the movable portion is supported by 4 to 10 wires and also serves as a lead wire for supplying power to the drive coil attached to the movable portion. Yes.

  In addition, since the miniature camera module has a strong demand for lowering the height together with the smartphone case, the camera shake correction device is also extremely small, and the effective length of the suspension wire is difficult to earn. However, the camera shake correction device cannot obtain a sufficient camera shake correction effect without a certain operating range. Therefore, there is a demand for a design in which the effective length is shortened and the suspension wire diameter is reduced.

  In addition, as the quality of cameras increases, the number of effective pixels exceeds 13M has become mainstream. In order to increase the number of pixels, it is essential to increase the size of the lens. Therefore, the mass of the movable part is increased, and the stress load on the suspension wire is increasing. Furthermore, since smartphones are used as precision electronic devices while being carried outside, they may be accidentally dropped during use, or the smartphone itself may contact or collide with the target site as an IC card terminal many times. is assumed. Therefore, extremely high strength is required for the suspension wire in the camera module.

  Moreover, since a smart phone is used for a long time, reduction of power consumption is calculated | required. Therefore, it is desirable that the conductive member constituting the smartphone has a low electrical resistance.

  The present invention has been made to solve the above problems. An object of the present invention is to provide a suspension wire that is short, has a sufficient spring property, is thin, strong, and has excellent conductivity.

  A suspension wire according to the present invention for solving the above problems is a suspension wire made of a Cu-15Ni-8Sn alloy used in a micro camera module. The suspension wire according to the present invention has an outer diameter including a conductive plating layer in the range of 30 μm or more and 60 μm or less, a tensile strength of 1400 MPa or more, and a conductivity of 9% IACS or more and 18% IACS or less. It is characterized by being.

  According to this invention, since the outer diameter including the conductive plating layer is within the above range, it can be suitably used as a suspension wire for a camera shake correction device provided in a micro camera module built in a small portable device such as a smartphone. Can do. Even if the diameter is within the above range, the tensile strength is 1400 MPa or more, which is preferable as a suspension wire for a camera shake correction device. Furthermore, even if an impact such as a drop is applied to a small portable device such as a smartphone, the suspension wire is not broken or deformed. Further, since the conductivity of the suspension wire including the conductive plating layer is within the above range, it exhibits good conductivity and can contribute to reduction of power consumption. A Cu-15Ni-8Sn alloy in such a range can preferably have improved tensile strength by spinodal decomposition in the tension annealing step.

  In the suspension wire according to the present invention, the conductive plating layer is preferably a silver plating layer, a copper plating layer, or a gold plating layer.

  According to this invention, electroconductivity can be improved by providing the above-mentioned electroconductive plating layer. In addition, the conductivity can be adjusted by changing the thickness of the conductive plating layer. As a result, it can be suitably operated as a suspension wire for a camera shake correction device. In addition, the above-mentioned electroconductive plating layer is excellent in solderability, and can improve the workability | operativity.

  In the suspension wire according to the present invention, the silver plating layer preferably has a cross-sectional area ratio (percentage) of the suspension wire in a range of 1% to 10%.

  According to this invention, the conductivity can be increased without reducing the strength (tensile strength) of the suspension wire.

  ADVANTAGE OF THE INVENTION According to this invention, the thin and strong suspension wire excellent in electroconductivity provided with sufficient spring property can be provided. Therefore, it can be suitably used as a suspension wire for a camera shake correction device provided in a micro camera module built in a small portable device such as a smartphone.

1 is a perspective view showing a suspension wire according to Embodiment 1. FIG. It is a graph which shows the relationship between the cross-sectional area ratio (percentage) of a silver plating layer, tensile strength, and electrical conductivity.

  A suspension wire according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below.

[Suspension wire]
As shown in FIG. 1, the suspension wire 10 according to the present invention is made of a Cu-15Ni-8Sn alloy used in a micro camera module. The outer diameter including the conductive plating layer is in the range of 30 μm or more and 60 μm or less, the tensile strength is 1400 MPa or more, and the conductivity is in the range of 9% IACS or more and 18% IACS or less.

  Since the outer diameter including the conductive plating layer is within the above range, the suspension wire 10 is preferably used as a suspension wire for a camera shake correction device provided in a micro camera module built in a small portable device such as a smartphone. Can do. Even if the diameter is within the above range, the tensile strength is 1400 MPa or more, which is preferable as a suspension wire for a camera shake correction device. In addition, even if an impact such as a drop is applied to a small portable device such as a smartphone, the suspension wire is not broken or deformed. Further, since the conductivity of the suspension wire including the conductive plating layer is within the above range, it exhibits good conductivity and can contribute to reduction of power consumption. A Cu-15Ni-8Sn alloy in such a range can preferably have improved tensile strength by spinodal decomposition in the tension annealing step.

  Hereinafter, the components of the suspension wire will be described in detail.

(Cu-15Ni-8Sn alloy)
The Cu-15Ni-8Sn alloy can be suitably used as a strand of a suspension wire for a camera shake correction device. In particular, this alloy is preferable in terms of workability, strength, conductivity, and the like. In addition, since this alloy is non-magnetic, it is not affected by magnets (permanent magnets, etc.) mounted around the suspension wire in the camera shake correction device provided in the ultra-small camera module built in a small portable device such as a smartphone. .

  Since the main component of Cu-15Ni-8Sn alloy is Cu, it can be easily processed into a predetermined wire diameter by cold drawing. For example, this alloy can be easily processed into a thin strand having a diameter of 30 μm or more and 60 μm or less. The wire drawing is performed using a die, and after processing to a predetermined wire diameter within a range of 30 μm or more and 60 μm or less, tension annealing can be performed to give a predetermined straightness.

  The straightness is not particularly limited, but the radius of curvature is preferably 600 mm or more. When a Cu-15Ni-8Sn alloy is used as a suspension wire for a camera shake correction device, high straightness is required to realize highly accurate positioning and operation. However, since the present invention has a straightness with a radius of curvature of 600 mm or more, this requirement can be satisfied. Note that tension annealing conditions for obtaining a predetermined radius of curvature are not particularly limited. For example, a Cu-15Ni-8Sn alloy wire loaded with a predetermined back tension is placed in a heating furnace at around 400 ° C. It can be controlled by passing at a speed. Further, as a process for setting the straightness within a predetermined range, for example, a rotary die type straightening device or the like can be applied.

  After the tension annealing, an aging treatment can be performed to give a predetermined strength. The improvement in strength due to this aging treatment is due to spinodal decomposition of the alloy components. Spinodal decomposition is a phenomenon in which mechanical strength is improved by aging treatment, and is a phenomenon in which two types of chemically different phases having the same crystal structure are formed. The aging treatment conditions are not limited because they are controlled in order to obtain a predetermined strength. Time treatment is preferred.

  As for the components of the Cu-15Ni-8Sn alloy, it is preferable that Ni is around 15% by mass, Sn is around 8% by mass, Cu is the balance and inevitable impurities. Since the Cu-15Ni-8Sn alloy in such a range is easy to process, a desired tensile strength can be obtained in the aging treatment step after the tension annealing step.

  The Ni content is around 15% by mass, but a range of 10% by mass to 20% by mass is allowed. When Ni is less than 10% by mass, the strength is lowered, and specifically, the tensile strength may not be 1400 MPa or more. On the other hand, if Ni exceeds 20% by mass, the electrical conductivity may decrease, and the electrical conductivity of 9% IACS to 18% IACS may not be reached. By setting it within this range, there is an advantage that an increase in strength due to solid solution hardening and spinodal decomposition can be effectively obtained. On the other hand, if the Ni content is outside the above range, a single-phase homogeneous supersaturated solid solution may not be formed in the solution treatment, and the subsequent spinodal decomposition may not occur suitably. In addition, preferable Ni content exists in the range of 12 mass% or more and 18 mass% or less.

  The Sn-containing layer is about 8% by mass, but allows a range of 6% by mass to 10% by mass. By setting it within this range, there is an advantage that an increase in strength due to solid solution hardening and spinodal decomposition can be effectively obtained. On the other hand, if the Ni content and the Sn content are outside the above ranges, a single-phase homogeneous supersaturated solid solution may not be formed in the solution treatment, and the subsequent spinodal decomposition may not occur suitably. In addition, a preferable Sn content layer exists in the range of 7% or more and 9 mass% or less.

  Cu is the balance other than Ni, Sn, and inevitable impurities, and the inevitable impurities are less than about 0.1% by mass. When inevitable impurities are contained in such a range, workability and tensile strength are improved.

  Note that the unavoidable impurities include one or more elements such as S, P, O, H, Nb, Fe, V, and Ta. Some of these elements are included from the time of manufacture of the master alloy of the Cu-15Ni-8Sn alloy, while other elements are included during the processing. The content of inevitable impurities is about 0.1% by mass or less in total, and each element is contained at about 0.05% by mass or less.

(Conductive plating layer)
The conductive plating layer 2 is provided on the outer periphery of the Cu-15Ni-8Sn alloy wire, and is preferably provided in order to obtain a suspension wire for a camera shake correction device having excellent conductivity. The thickness of the conductive plating layer is provided such that the outer diameter of the suspension wire including the conductive plating layer is in the range of 30 μm to 60 μm. The conductive plating layer is provided so that the conductivity of the suspension wire is in the range of 9% IACS to 18% IACS. Since the conductivity of the suspension wire including the conductive plating layer is within the above range, the suspension wire exhibits good conductivity, can contribute to a reduction in power consumption, and is preferably operated as a suspension wire for a camera shake correction device. Can do. The conductivity is a value measured by a four-terminal resistance measurement method.

  The conductivity can be adjusted by changing the type of the conductive plating layer or changing the thickness of the conductive plating layer. When the electrical conductivity is less than 9% IACS, the strength (tensile strength) is increased because it is obtained when the thickness of the conductive plating layer is thin. However, since the electrical conductivity is not sufficient, it contributes enough to reduce power consumption. There are things that cannot be done. On the other hand, when the electrical conductivity exceeds 18% IACS, the electrical conductivity is increased because it is obtained when the thickness of the conductive plating layer is thick, but the strength (tensile strength) may be decreased to be less than 1400 MPa.

  The conductive plating layer is selected from a silver plating layer, a copper plating layer, and a gold plating layer. By providing such a conductive plating layer, the conductivity can be enhanced without reducing the strength (tensile strength). Note that these conductive plating layers are excellent in solderability and also have the advantage that the workability can be improved.

  As will be described later in the examples, for example, when the conductive plating layer is a silver plating layer, the thickness of the silver plating layer is in the range of 1% to 10% in terms of the cross-sectional area ratio (percentage) of the entire suspension wire. It is preferable to be within. If the cross-sectional area ratio of the entire suspension wire is less than 1%, the strength (tensile strength) is increased, but the conductivity may be smaller than 9% IACS. On the other hand, if the cross-sectional area ratio of the entire suspension wire exceeds 10%, the electrical conductivity increases, but the silver plating layer becomes considerably thick and the cost increases, and the strength of the entire suspension wire decreases. The term “whole suspension wire” here refers to the suspension wire itself, and is synonymous with a suspension wire composed of a Cu-15Ni-8Sn alloy wire and a conductive plating layer provided on the outer periphery thereof.

  When the conductive plating layer is a copper plating layer, the thickness of the copper plating layer is preferably in the range of 1.2% to 10.6% in terms of the cross-sectional area ratio (percentage) of the entire suspension wire. The reason why this range is slightly different from the case of the silver plating layer is based on the difference in conductivity between the silver plating layer and the copper plating layer. If the cross-sectional area ratio of the entire suspension wire is less than 1.2%, the strength (tensile strength) is high, but the conductivity may be smaller than 9% IACS. On the other hand, if the cross-sectional area ratio of the entire suspension wire exceeds 10.6%, the electrical conductivity increases, but the copper plating layer becomes considerably thick and costs increase, and the strength of the entire suspension wire decreases.

  When a gold plating layer is applied as the conductive plating layer, the cross-sectional area ratio of the entire suspension wire is set based on the conductivity difference between the silver plating layer or the copper plating layer and the gold plating layer as described above.

  In addition, the solderability by providing the electroconductive plating layer chosen from a silver plating layer, a copper plating layer, and a gold plating layer is favorable. In particular, when a silver plating layer is provided, more excellent solderability is exhibited. For example, when a solder wettability test was performed on a 0.050 mm core wire under the same soldering conditions, good solderability was confirmed in 0.1 seconds when a silver plating layer was provided with a thickness of 0.3 μm. On the other hand, when the Sn plating layer was provided at 0.75 μm, it was 0.3 seconds. From these test results, it was found that by providing the silver plating layer, soldering can be performed in about 1/3 of the time when the Sn plating layer is provided. Therefore, by providing the silver plating layer, it is possible to reduce the decrease in the outer diameter due to solder erosion.

(Other)
The suspension wire may be provided with other layers as necessary. For example, an insulating film may be provided. As the insulating film, at least one or two or more resin films selected from polyurethane resin, polyester resin, polyesterimide resin, and polyamideimide resin can be provided. In particular, a solderable urethane resin film or the like is preferable as the insulating film. Although the thickness of an insulating film is not specifically limited, For example, it is preferable to exist in the range of 3 micrometers or more and 10 micrometers or less. Further, a layer such as nylon or fusion coating may be provided on the insulating film.

  Moreover, you may provide the base film of a conductive plating layer. For example, when the conductive plating layer is a copper plating layer, it is preferable to provide a thin nickel plating layer as a base film for the copper plating layer.

  As described above, the suspension wire 10 according to the present invention has a thin outer diameter including a conductive plating layer, and is suitable as a suspension wire for a camera shake correction device included in a micro camera module built in a small portable device such as a smartphone. Can be used for Even if the diameter is small, the tensile strength is 1400 MPa or more, which is preferable as a suspension wire for a camera shake correction device. In addition, even if an impact such as dropping is applied to a small portable device such as a smartphone, there is an effect that disconnection or deformation does not occur. In addition, since the suspension wire including the conductive plating layer exhibits good conductivity, it can contribute to reduction of power consumption.

  Note that the tensile strength of the suspension wire 10 is preferably 1400 MPa or more when the outer diameter is in the range of 30 μm to 60 μm. The tensile strength of the suspension wire 10 is more preferably 1500 MPa or more. A suspension wire having a tensile strength of 1500 MPa or more and an outer diameter of 30 μm or more and 60 μm or less is used for a camera shake correction device provided in a micro camera module built in a small portable device such as a smartphone from the viewpoint of improving drop impact resistance. Particularly preferred as a suspension wire. Note that the tensile strength of the suspension wire can also be controlled by aging treatment conditions.

(Image stabilizer)
The suspension wire according to the present invention is used in various types of camera shake correction devices as described in Patent Document 3. The camera shake correction device is provided in a small portable device such as a smartphone equipped with a micro camera module. The camera shake correction device has a camera shake correction function that corrects a lens position that is displaced by vibration when taking a picture. Since the unit having such a camera shake correction function is extremely small, it is sufficient to use a thin and high tensile strength wire having an outer diameter of 30 μm or more and 60 μm or less like the above-described suspension wire according to the present invention. Cannot be configured.

  The ultra-small camera module, for example, generates a lens, a suspension wire that elastically urges the lens to an initial position in the optical axis direction, and an electromagnetic force that resists the urging force of the suspension wire to cause the lens to be an optical axis. On the other hand, it basically includes electromagnetic driving means that can be driven in the vertical direction. There are various configurations for the electromagnetic drive means. For example, a cylindrical yoke, a coil accommodated inside the inner peripheral wall of the yoke, and surrounding the coil and accommodated inside the outer peripheral wall of the yoke. Some have a magnet.

  The suspension wire acts to elastically urge the lens to the initial position in the direction perpendicular to the optical axis, and also acts as a power feeding path to the coil. Therefore, the suspension wire is required to have high tensile strength and conductivity. Since the suspension wire is soldered to the lead wire as a power feeding path to the coil, good solderability is also required. The lens is mounted on a lens carrier, and a coil is mounted on the lens carrier. Normally, this lens carrier is supported by 4 to 10 suspension wires at four corners.

  In the optical pickup, an impact absorbing material such as α gel can be applied to the base of the suspension wire. However, a camera shake correction device for a small portable device such as a smartphone equipped with a micro camera module has a small space at the base of the suspension wire. Moreover, the space is indirectly given. For this reason, there is a structural difference in that the impact on the suspension wire is increased due to a drop impact or the like, and the impact is hardly absorbed. On the other hand, the lens has a large diameter due to the need for higher pixels, and the mass of the movable part on which the suspension wire is suspended tends to increase. Such an increase in the mass of the movable part causes a large stress to be applied to the suspension wire that has become thinner due to the low profile. However, the present invention can effectively solve such problems and can provide a suspension wire for a camera shake correction apparatus that cannot be applied to a conventional suspension wire for an optical pickup.

  The present invention will be described in more detail with reference to examples and comparative examples.

[Example 1]
A bus bar of an outer diameter of 0.3 mm of a Cu-15Ni-8Sn alloy (trade name: Equimet 3, Materion Brush) was used. This Cu-15Ni-8Sn alloy is Ni: 15% by mass, Sn: 8% by mass, and Cu: remainder (about 77% by mass). The bus bar was subjected to silver plating with a thickness of 1.5 μm, and cold-drawn to 0.040 mm by a multistage wire drawing machine. The cross-sectional area reduction rate per die was in the range of 5% to 20%, and the drawing speed was 300 m / min. A back tension of 30 to 70 g was added to the wire after the wire drawing step, and the wire was run in an electric furnace having a furnace temperature of 400 ° C., a furnace length of 3 m, and an inert atmosphere at a linear speed of 7.5 m / min. The radius of curvature after this step was 1000 mm.

  The wire rod after the tension annealing step was passed through an electric furnace having a furnace temperature of 400 ° C., a furnace length of 3 m, and an inert atmosphere at a line speed of 10 m / min. The tensile strength after this step was 1543 MPa. This improvement in tensile strength is due to the spinodal decomposition of the alloy components. The Larson mirror value (LM value) at this time was 12.0. The Larson mirror value is a parameter determined by the heat treatment temperature and time. When this LM value is large, it can be said that the heat treatment load is large. On the other hand, when the LM value is small, it can be said that the heat treatment load is small. Thus, a Cu-15Ni-8Sn alloy wire having an outer diameter of 0.040 mm and having a silver plating layer of 0.2 μm was obtained. The cross-sectional area ratio of the silver plating layer at this time is 2%. Thereafter, the alloy wire was cut into a length of 20 mm to produce a suspension wire for a camera shake correction device.

  The obtained suspension wire had an outer diameter of 0.040 mm, a length of 20.0 mm, and a tensile strength of 1543 MPa. The conductivity was 10% IACS. The cross-sectional area ratio of the silver plating layer in the cross section of the suspension wire was 2%. The tensile strength was measured with a small desktop tensile tester (Shimadzu Corporation, EZ-TEST). The conductivity was measured by a 4-terminal resistance measurement method.

[Example 2]
In Example 1, the outer diameter of the Cu-15Ni-8Sn alloy wire was 0.030 mm, and the silver plating layer was provided with a thickness of 0.15 μm. Otherwise, the suspension wire of Example 2 was obtained in the same manner as Example 1. The obtained suspension wire had an outer diameter of 0.030 mm and a tensile strength of 1550 MPa. The conductivity was 10% IACS.

[Example 3]
In Example 1, the outer diameter of the Cu-15Ni-8Sn alloy wire was 0.060 mm, and the silver plating layer was provided with a thickness of 0.3 μm. Otherwise, the suspension wire of Example 3 was obtained in the same manner as Example 1. The obtained suspension wire had an outer diameter of 0.060 mm and a tensile strength of 1530 MPa. The conductivity was 10% IACS.

[Comparative Example 1]
In Example 1, the outer diameter of the Cu-15Ni-8Sn alloy wire was 0.100 mm, and the silver plating layer was provided with a thickness of 0.5 μm. Otherwise, the suspension wire of Comparative Example 1 was obtained in the same manner as Example 1. The obtained suspension wire had an outer diameter of 0.100 mm and a tensile strength of 1350 MPa. The conductivity was 10% IACS.

[Comparative Example 2]
In Example 1, the outer diameter of the Cu-15Ni-8Sn alloy wire was 0.070 mm, and the silver plating layer was provided with a thickness of 0.35 μm. Otherwise, the suspension wire of Comparative Example 1 was obtained in the same manner as Example 1. The obtained suspension wire had an outer diameter of 0.070 mm and a tensile strength of 1380 MPa. The conductivity was 10% IACS.

[Evaluation]
The suspension wires obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated by applying them to a camera shake correction apparatus. Evaluation with the image stabilizer was performed by a drop impact test. The drop impact test was evaluated by a high place drop test with a drop altitude of 200 cm and a number of drops of 20 times and a low place drop test with a drop altitude of 30 cm and a number of drops of 20000.

  From the evaluation results with the image stabilizer, the outer diameter including the conductive plating layer is in the range of 0.030 to 0.060 mm, the tensile strength is 1400 MPa or more, and the conductivity is 9% IACS or more and 18% IACS or less. The suspension wire in the range was excellent as a suspension wire for a camera shake correction device. In particular, when the tensile strength was 1500 MPa or more, it was possible to show more excellent durability in a drop impact test using a camera shake correction device. In addition, FIG. 2 is a graph which shows the relationship between the cross-sectional area ratio (percentage) of a silver plating layer, tensile strength, and electrical conductivity.

  In addition, the suspension wire provided with the silver plating layer so that the electrical conductivity is 9% IACS or more was excellent in low power consumption and DC (low frequency) sensitivity in the basic operation characteristic evaluation with the camera shake correction device.

  On the other hand, suspension wires having an outer diameter exceeding 0.060 mm and a tensile strength of less than 1400 were inferior in drop impact resistance and a reduction in unit height in a camera shake correction device. In addition, the suspension wire provided with the silver plating layer so that the electrical conductivity is less than 9% IACS was slightly inferior in power consumption in the basic operation characteristic evaluation with the image stabilizer.

  From the above results, it was found that the suspension wire according to the present invention described above obtained a preferable result in terms of drop impact resistance and power consumption in the camera shake correction apparatus.

1 Cu-15Ni-8Sn alloy wire (alloy wire)
2 Conductive plating layer 10 Suspension wire

Claims (3)

A suspension wire made of a Cu-15Ni-8Sn alloy used in a micro camera module,
A suspension wire having an outer diameter including a conductive plating layer in a range of 30 μm or more and 60 μm or less, a tensile strength of 1400 MPa or more, and a conductivity of 9% IACS or more and 18% IACS or less.   The suspension wire according to claim 1, wherein the conductive plating layer is a silver plating layer, a copper plating layer, or a gold plating layer.   The suspension wire according to claim 2, wherein the silver plating layer has a cross-sectional area ratio of the suspension wire in a range of 1% to 10%.

Images