TW201410886A - High-strength titanium-copper foil, and method for producing same - Google Patents

Abstract

Provided is a high-strength titanium-copper foil which is suitable as an electrically conductive spring material that can be used in an electronic device component such as an autofocus camera module. A titanium-copper foil, which comprises Ti in an amount of 1.5 to 5.0 mass% and a remainder made up by copper and unavoidable impurities and has a 0.2% proof stress of 1100 MPa or more as measured in a direction parallel to the rolling direction and an arithmetic average roughness (Ra) of 0.1 mum or less as measured in a direction perpendicular to the rolling direction.

Description

High-strength titanium copper foil and manufacturing method thereof

The present invention relates to a Cu-Ti-based alloy foil having excellent strength suitable as an electrically conductive spring material such as an autofocus camera module.

An electronic component called an autofocus camera module is used in the camera lens portion of the mobile phone. The autofocus function of the camera of the mobile phone uses the elastic force of the material used in the autofocus camera module to move the lens in a fixed direction, and on the other hand, the electromagnetic force generated by the current flowing through the coil wound around the camera. The lens is moved in a direction opposite to the direction in which the elastic force of the material acts. The camera lens is driven by such a mechanism to exert an autofocus function (for example, Patent Documents 1 and 2).

Therefore, for the copper alloy foil used in the autofocus camera module, the strength to withstand the deformation of the material caused by the electromagnetic force is required. If the strength is low, the material cannot withstand the displacement caused by the electromagnetic force and undergo permanent deformation (aging). If aging occurs, the lens cannot move to the desired position when the fixed current flows, and the autofocus function cannot be performed.

In the autofocus camera module, a Cu-Ni-Sn-based copper alloy foil having a foil thickness of 0.1 mm or less and a 0.2% guaranteed stress of 1100 MPa or more is used. However, due to the cost reduction requirements in recent years, titanium copper foils having a lower material price than Cu-Ni-Sn-based copper alloys have been used, and their demand has gradually increased.

On the other hand, the strength of the titanium copper foil is lower than that of the Cu-Ni-Sn copper alloy foil. The problem of aging is expected, so it is expected to increase its strength. As a technique for improving the strength of titanium copper, Patent Document 3 proposes a method of adjusting the average crystal grain size by final recrystallization annealing, and then sequentially performing cold rolling and aging treatment, which is proposed in Patent Document 4 After the solution treatment, the method of cold rolling, aging treatment, and cold rolling is sequentially performed. In Patent Document 5, after hot rolling and cold rolling, it is maintained in a temperature range of 750 to 1000 ° C for 5 seconds to 5 minutes. Dissolving treatment, and then sequentially performing cold rolling of 0 to 50% of rolling rate, aging treatment of 300 to 550 ° C, and final cold rolling of rolling reduction of 0 to 30%, thereby adjusting the surface of the panel by {420} The method of X-ray diffraction intensity is proposed in Patent Document 6 to perform the first solution treatment, the intermediate rolling, the final solution treatment, the annealing, the final cold rolling, and the timely treatment under the specific conditions. This method of adjusting the half-height of the X-ray diffraction intensity of {220} in the rolling surface.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2004-280031

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2009-115895

[Patent Document 3] Japanese Patent No. 4001491

[Patent Document 4] Japanese Patent No. 4259828

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2010-126777

[Patent Document 6] Japanese Patent Laid-Open Publication No. 2011-208243

In the examples and comparative examples of Patent Documents 3 to 6, it was also found that there were some titanium copper having a 0.2% guaranteed stress of 1100 MPa or more. However, in the case of the above-described conventional technique, it is understood that when the thickness of the foil is as thin as 0.1 mm or less, when a load is applied to the material to deform it, the load is removed. It will age, and if it is only high strength, it cannot be used as a conductive spring material such as an autofocus camera module.

Accordingly, it is an object of the present invention to provide a high strength titanium copper foil suitable as an electrically conductive spring material for use in electronic machine parts such as autofocus camera modules. Further, another object of the present invention is to provide a method for producing such a titanium copper foil.

The inventors of the present invention have tried to investigate the relationship between the 0.2% proof stress and the aging of the titanium copper foil and the relationship between the surface roughness and the aging, and found that the higher the 0.2% proof stress and the smaller the surface roughness, the smaller the aging amount. The present invention has been completed in the light of the above findings and is defined by the following.

(1) A titanium copper foil containing 1.5 to 5.0% by mass of Ti, and the balance being composed of copper and unavoidable impurities, and a 0.2% proof stress in a direction parallel to the rolling direction is 1100 MPa or more, and The arithmetic mean roughness (Ra) in the direction perpendicular to the rolling direction is 0.1 μm or less.

(2) The titanium copper foil according to (1), wherein the 0.2% proof stress is 1200 MPa or more.

(3) The titanium copper foil according to (1) or (2), wherein the foil thickness is 0.1 mm or less.

(4) The titanium copper foil according to any one of (1) to (3), which contains a total amount of 0 to 1.0% by mass of Ag, B, Co, Fe, Mg, Mn, Mo, Ni, P, Si One or more of Cr, and Zr.

(5) A method for producing a titanium copper foil, comprising: producing an ingot containing 1.5 to 5.0% by mass of Ti and remaining a portion of copper and unavoidable impurities, and sequentially hot rolling and cooling the ingot Rolling, followed by sequential solution treatment at 700~1000 °C for 5 seconds to 30 minutes, cold rolling with a rolling reduction of 55% or more, aging treatment at 200 to 450 °C for 2 to 20 hours, and rolling reduction rate It is a final cold rolling of 35% or more, and is rolled by a work roll having an arithmetic mean roughness (Ra) of 0.1 μm or less in the final pass of the final cold rolling.

(6) The method for producing a titanium copper foil according to (5), wherein the ingot contains Ag, B, Co, Fe, Mg, Mn, Mo, Ni, P, Si in a total amount of 0 to 1.0% by mass. One or more of Cr and Zr.

(7) A copper-clad product comprising the titanium copper foil according to any one of (1) to (4).

(8) An electronic machine part comprising the titanium copper foil according to any one of (1) to (4).

(9) The electronic machine part of (8), wherein the electronic machine part is an autofocus camera module.

(10) An autofocus camera module having a lens; a spring member that elastically presses the lens to an initial position in an optical axis direction; and an electromagnetic driving means that generates an electromagnetic force against an elastic force of the spring member The lens may be driven in the optical axis direction; and the spring member may be the titanium copper foil according to any one of (1) to (4).

A high-strength Cu-Ti alloy foil suitable for use as a conductive spring material for electronic equipment parts such as camera modules can be obtained.

1‧‧‧Auto Focus Camera Module

2‧‧‧Y yoke

3‧‧‧ lens

4‧‧‧ magnet

5‧‧‧ bracket

6‧‧‧ coil

7‧‧‧Base

8‧‧‧Frame

9a‧‧‧Spring member on the upper side

9b‧‧‧lower spring member

10a, 10b‧‧‧ cover

1 is a cross-sectional view showing the autofocus camera module of the present invention.

2 is an exploded perspective view of the autofocus camera module of FIG. 1.

3 is a cross-sectional view showing the operation of the autofocus camera module of FIG. 1.

Fig. 4 is a schematic view showing a method of measuring the amount of aging.

(1) Ti concentration

In the titanium copper of the present invention, the Ti concentration is 1.5 to 5.0% by mass. Titanium and copper are solid-dissolved in the Cu matrix by solid solution treatment, and the fine precipitates are dispersed in the alloy by aging treatment, and the strength and electrical conductivity are increased.

When the Ti concentration is less than 1.5% by mass, the precipitation of precipitates becomes insufficient and the desired strength cannot be obtained. When the Ti concentration exceeds 5.0% by mass, the workability is deteriorated, and the material is easily broken at the time of rolling. When the balance between strength and workability is considered, the preferred Ti concentration is 2.9 to 3.5% by mass.

(2) Other added elements

In the titanium copper of the present invention, one or more of Ag, B, Co, Fe, Mg, Mn, Mo, Ni, P, Si, Cr, and Zr may be contained in a total amount of 0 to 1.0% by mass. Further increase the strength. The total content of these elements may also be zero, that is, the elements may not be included. The reason why the upper limit of the total content of the elements is 1.0% by mass is that when it exceeds 1.0% by mass, the workability is deteriorated, and the material is easily broken at the time of rolling. In consideration of the balance between strength and workability, it is preferred to contain one or more of the above elements in a total amount of 0.005 to 0.5% by mass.

(3) 0.2% guaranteed stress

The 0.2% guaranteed stress required for the titanium copper foil which is suitable as the conductive spring material of the autofocus camera module is 1100 MPa or more. In the titanium copper of the present invention, the 0.2% proof stress in the direction parallel to the rolling direction can be achieved. 1100MPa or more. The 0.2% proof stress of the titanium copper foil of the present invention is 1200 MPa or more in the preferred embodiment, and 1300 MPa or more in the more preferred embodiment.

The upper limit of the 0.2% guaranteed stress is not particularly limited in terms of the strength of the object of the present invention, but it takes time and expense, so the 0.2% guarantee of the titanium copper foil of the present invention is guaranteed. The stress is generally 2000 MPa or less, and is generally 1600 MPa or less.

In the present invention, the 0.2% proof stress in the direction parallel to the rolling direction of the titanium copper foil is measured in accordance with JIS Z2241 (Metal Material Tensile Test Method).

(4) Surface roughness (Ra)

In general, the thickness of the conductive spring material used in the autofocus camera module or the like is 0.1 mm or less. When the material is loaded, the stress is concentrated in the thinnest part of the foil thickness of the material. If the surface roughness of the material is large, that is, the thicker portion of the material and the thinner portion of the material are present locally, the stress concentrates on the thinner portion of the foil and aging occurs. On the other hand, if the surface roughness of the material is small, even when a load is applied to the material, stress is hard to concentrate on a specific point, and aging is less likely to occur.

According to the results of the study by the present inventors, it is understood that when the arithmetic mean roughness (Ra) is controlled to 0.1 μm or less, the aging resistance is remarkably improved. Therefore, the titanium-titanium foil of the present invention has an arithmetic mean roughness (Ra) of 0.1 μm or less, preferably 0.08 μm or less, more preferably 0.06 μm or less. The lower limit of the surface roughness is not particularly limited in terms of the strength of the object of the present invention. However, since it takes time and cost to produce an extremely small arithmetic mean roughness (Ra), the arithmetic mean roughness (Ra) is 0.01 μm or more in a general embodiment, and is 0.02 μm or more in a more general embodiment.

In the present invention, a roughness curve having a reference length of 300 μm is selected along a direction perpendicular to the rolling direction of the titanium copper foil, and an arithmetic mean roughness (Ra) is measured in accordance with JIS B 0601 from the curve.

(5) Thickness of copper foil

In one embodiment of the titanium copper foil of the present invention, the foil thickness is 0.1 mm or less, which is generally implemented. The foil thickness in the form is 0.08 to 0.03 mm, and in a more general embodiment, the foil thickness is 0.05 to 0.03 mm.

(6) Manufacturing method

In the manufacturing process of the titanium copper foil of the present invention, first, a raw material such as electrolytic copper or Ti is melted in a melting furnace to obtain a melt having a desired composition. The melt is then cast into an ingot. In order to prevent oxidative wear of titanium, it is preferred that the melting and casting be carried out in a vacuum or in an inert gas atmosphere. Thereafter, hot rolling, cold rolling 1, solution treatment, cold rolling 2, aging treatment, and cold rolling 3 are sequentially performed to finish into a foil having a desired thickness and characteristics.

The conditions of hot rolling and subsequent cold rolling 1 are as long as they are carried out under the customary conditions in the manufacture of titanium copper, and there are no special requirements. Further, the solution treatment may be a conventional condition, and for example, it can be carried out at 700 to 1000 ° C for 5 seconds to 30 minutes.

In order to obtain the above strength, it is preferable to set the rolling reduction ratio of the cold rolling 2 to 55% or more. More preferably, it is 60% or more, and the best is 65%. If the rolling reduction ratio is less than 55%, it is difficult to obtain a 0.2% proof stress of 1100 MPa or more. The upper limit of the rolling reduction ratio is not particularly specified in terms of the strength of the object of the present invention, but it is not more than 99.8% in the industry.

The aging treatment has a heating temperature of 200 to 450 ° C and a heating time of 2 to 20 hours. If the heating temperature is less than 200 ° C or exceeds 450 ° C, it is difficult to obtain a 0.2% proof stress of 1100 MPa or more. If the heating time is less than 2 hours or exceeds 20 hours, it is difficult to obtain a 0.2% proof stress of 1100 MPa or more.

The rolling reduction ratio of the cold rolling 3 is preferably set to be 35% or more. More preferably, it is 40% or more, and particularly preferably 45% or more. If the rolling reduction ratio is less than 35%, it is difficult to obtain a 0.2% proof stress of 1100 MPa or more. The upper limit of the rolling reduction ratio is not particularly specified in terms of the strength of the object of the present invention, but it is not more than 99.8% in the industry.

Further, in order to obtain the above surface roughness, it is important to use a work roll having a final pass arithmetic mean roughness (Ra) of cold rolling 3 of 0.1 μm or less, preferably 0.08 μm or less, more preferably 0.06 μm or less. . If the arithmetic mean roughness of the work rolls exceeds 0.1 μm, the surface roughness of the material easily exceeds 0.1 μm. However, it takes time and expense to form a minimum arithmetic mean roughness (Ra) of the work rolls, so the arithmetic mean roughness (Ra) is 0.01 μm or more in the general embodiment, and 0.02 in the more general embodiment. More than μm.

In the present invention, a roughness curve having a reference length of 400 μm is selected with respect to the longitudinal direction, that is, a direction corresponding to a direction perpendicular to the rolling direction of the material, and the arithmetic mean roughness of the work roll is measured in accordance with JIS B 0601 ( Ra).

The smaller the roughness of the rolling work roll, the easier the material in the rolling is to slide, and the abnormality such as breakage or winding deviation is likely to occur, so that the work roll used in the rolling is used for no particular reason. The greater the roughness, the better the industry. Therefore, in the present invention, it is preferable to use the work rolls having the above arithmetic mean roughness (Ra) of 0.1 μm or less only in the final pass of the cold rolling 3.

As in the case of titanium copper, in the case of a manufacturing method of heat treatment, pickling or polishing after final rolling, the surface quality depends on the polishing and polishing, so the arithmetic mean roughness of the work rolls used in the rolling ( Ra) is usually 0.13 μm or more. Therefore, it is known from the inventors that a work roll having a low roughness as described above is not used.

Further, in general, after the aging treatment, in order to remove the surface oxide film formed at the time of aging, pickling or polishing of the surface is performed. In the present invention, pickling or polishing of the surface may be performed after the aging treatment. Further, after the cold rolling 3, low-temperature annealing may be performed, and thereafter, in order to remove the surface oxide film formed during the low-temperature annealing, pickling or polishing of the surface may be performed. However, in this case, the effect of the present invention cannot be exhibited if the surface roughness after polishing is not within the range specified by the present invention. In the polishing for removing the oxide film which is conventionally carried out, since the polishing roughness used for the polishing is large, an even smooth surface specified in the present invention cannot be obtained. In order to obtain the surface roughness specified in the present invention by grinding, it is necessary to reduce the polishing roughness and the like.

(7) Use

The titanium copper foil of the present invention is not limited, and can be preferably used as a material for electronic equipment parts such as switches, connectors, jacks, terminals, and relays, and particularly preferably used as an electronic device such as an autofocus camera module. Conductive spring material used in machine parts. The autofocus camera module includes a lens in one embodiment, a spring member that elastically presses the lens to an initial position in the optical axis direction, and an electromagnetic driving means that generates an electromagnetic force that resists the elastic pressure of the spring member. The above lens can be driven in the optical axis direction. Electromagnetic driving means can be exemplified a yoke having a cylindrical shape; a coil housed inside the inner peripheral wall of the yoke; and a magnet surrounding the coil and housed inside the peripheral wall of the yoke.

1 is a cross-sectional view showing an example of an autofocus camera module of the present invention, FIG. 2 is an exploded perspective view of the autofocus camera module of FIG. 1, and FIG. 3 is a cross-sectional view showing the operation of the autofocus camera module of FIG. .

The auto focus camera module 1 has: a yoke 2 having a cylindrical shape; a magnet 4 attached to the outer wall of the yoke 2; a bracket 5 having a lens 3 at a central position; a coil 6 mounted to the bracket 5; and a base 7 Mounted with a yoke 2; frame 8 supporting the base 7; 2 spring members 9a, 9b equal to the upper and lower support brackets 5; and 2 caps 10a, 10b covering the spring members 9a, 9b Above and below. The two spring members 9a and 9b are the same article, and are clamped from the upper and lower sides in the same positional relationship and support the bracket 5, and function as a power supply path to the coil 6. The carriage 5 is moved upward by applying a current to the coil 6. In addition, in the present specification, the upper and lower terms are appropriately used, and when it is displayed above and below in FIG. 1, the upper position indicates the positional relationship from the camera toward the subject.

The yoke 2 is a magnet such as soft iron, and the upper surface portion is closed. The zigzag has a cylindrical shape and has a cylindrical inner wall 2a and an outer wall 2b. to The inner surface of the outer wall 2b of the glyph is attached (and then) with a ring-shaped magnet 4.

The bracket 5 is a molded product formed of a synthetic resin or the like having a cylindrical structure of a bottom surface portion, supports the lens at a central position, and mounts the pre-formed coil 6 on the outer side of the bottom surface. The yoke 2 is fitted and assembled to the inner peripheral portion of the base 7 of the rectangular resin molded article, and the entire yoke 2 is fixed by the frame 8 of the resin molded article.

Each of the spring members 9a and 9b is fixed by the frame 8 and the base 7 respectively, and the slit portions of the inner peripheral portion which are spaced apart by 120° are fitted to the bracket 5, and are thermally caulking. ) and so on.

The spring member 9b and the base 7 and the spring member 9a and the frame 8 are fixed by thermal caulking or the like, and the cover 10b is attached to the bottom surface of the base 7, and the cover 10a is attached to the upper portion of the frame 8, respectively. The spring member 9b is sandwiched and fixed between the base 7 and the cover 10b, and the spring member 9a is sandwiched and fixed between the frame 8 and the cover 10a.

The lead wire on one side of the coil 6 is extended upward by a groove provided in the inner circumferential surface of the bracket 5, and is welded to the spring member 9a. The other lead is extended downward through a groove provided in the bottom surface of the bracket 5, and is welded to the spring member 9b.

The spring members 9a, 9b are plate springs of the titanium copper foil of the present invention. The spring member 9a, 9b have elasticity and elastically press the lens 3 to the initial position in the optical axis direction. At the same time, the spring members 9a, 9b also function as a power supply path to the coil 6. One of the outer peripheral portions of the spring members 9a and 9b protrudes to the outside to function as a feed terminal.

The cylindrical magnet 4 is magnetized in the radial (diameter) direction to form The inner wall 2a, the upper surface portion, and the outer wall 2b of the word-shaped yoke 2 are magnetic paths of the path, and the coil 6 is disposed in a gap between the magnet 4 and the inner wall 2a.

The spring members 9a and 9b have the same shape and are attached in the same positional relationship as shown in Figs. 1 and 2, so that the axial shift when the bracket 5 is moved upward can be suppressed. Since the coil 6 is formed by press-molding after being wound, the accuracy of the final outer diameter is improved, and it can be easily disposed in a specific narrow gap. The bracket 5 is in contact with the susceptor 7 at the lowest position, and is in contact with the yoke 2 at the uppermost position. Therefore, the bracket 5 is provided with a contact mechanism in the vertical direction to prevent falling off.

Fig. 3 is a cross-sectional view showing a state in which a current is applied to the coil 6 and the carriage having the lens 3 is moved to the upper side in the autofocus application. When a power source is applied to the feed terminals of the spring members 9a and 9b, a current flows through the coil 6 and an upward electromagnetic force acts on the carrier 5. On the other hand, the restoring force of the two connected spring members 9a and 9b acts on the bracket 5 downward. Therefore, the upward movement distance of the bracket 5 is a position at which the electromagnetic force and the restoring force are balanced. Thereby, the amount of movement of the carriage 5 can be determined by the amount of current applied to the coil 6.

The upper side spring member 9a supports the upper surface of the bracket 5, and the lower side spring member 9b supports the lower surface of the bracket 5, so that the restoring force acts on the upper surface and the lower surface of the bracket 5 equally downward, so that The axis shift of the lens 3 is suppressed to be small.

Therefore, when the bracket 5 is moved upward, it is not necessary to guide with a flange or the like. Since there is no sliding friction caused by the guiding, the amount of movement of the bracket 5 is purely by the electromagnetic force. It is balanced with the balance of the restoring force, so that the movement of the lens 3 with smoothness and precision can be achieved. Thereby, automatic focusing with less lens oscillation is achieved.

In addition, although the magnet 4 has been described as a cylindrical shape, the magnet 4 is not limited thereto, and may be divided into three or four portions and magnetized in the radial direction, and attached and fixed to the outer wall of the yoke 2. The inner surface of 2b.

[Examples]

In the following, the embodiments of the present invention are shown in conjunction with the comparative examples, but they are provided for a better understanding of the present invention and its advantages, and are not intended to limit the invention.

The alloy containing the alloy component shown in Table 1 and the remainder consisting of copper and unavoidable impurities was used as an experimental material, and the influence of the alloy composition and the manufacturing conditions on the 0.2% proof stress and aging was investigated.

2.5 kg of electrolytic copper was melted by a vacuum melting furnace, and alloying elements were added to obtain the alloy composition described in Table 1. The melt was cast into a mold made of cast iron to produce an ingot having a thickness of 30 mm, a width of 60 mm, and a length of 120 mm. The ingot was processed in the next step sequence to prepare a product sample having the specific foil thickness as described in Table 1.

(1) Hot rolling: The ingot was heated at 950 ° C for 3 hours and rolled to a thickness of 10 mm.

(2) Grinding: The scale formed in the hot rolling is removed by a grinder. The thickness after grinding is 9 mm.

(3) Cold rolling 1: Rolling to a specific thickness according to the rolling reduction ratio.

(4) Solution treatment: The sample was placed in an electric furnace heated to 800 ° C for 5 minutes, and then the sample was placed in a water tank for rapid cooling.

(5) Cold rolling 2: Rolling to a specific thickness according to the rolling reduction ratio.

(6) Aging treatment: heating was carried out in the temperature and time shown in Table 1, and in the Ar environment. This temperature is selected such that the tensile strength after aging is maximized.

(7) Pickling, polishing and polishing: In order to remove the scale formed by the aging treatment, polishing was carried out in a 15 vol% sulfuric acid-1.5 vol% aqueous peroxide solution.

(8) Cold rolling 3: The rolling was performed until the thickness of the foil shown in Table 1 was obtained. Further, the final pass of the rolling was performed using the work rolls of the roughness shown in Table 1.

The following samples were evaluated for the finished product samples.

(a) 0.2% guaranteed stress

The 0.2% proof stress in the direction parallel to the rolling direction was measured by the above-described measuring method using a tensile tester.

(b) Surface roughness

The arithmetic mean roughness (Ra) of the foil surface was determined by the above-described measurement method by a confocal microscope HD-100 manufactured by Lasertec. The measurement is carried out perpendicularly to the rolling direction.

(c) aging

A short strip sample having a width of 10 mm is selected in such a manner that the length direction becomes a parallel direction of rolling, as shown in Fig. 4, one end of the sample is fixed, and the punching machine that processes the front end into a knife edge moves at 1 mm/min. The speed is pressed against the position of the fixed end L, and after the deflection of the distance d is applied to the sample, the puncher is returned to the initial position and unloaded. After the unloading, the aging amount δ was obtained.

The test conditions are L=3 mm and d=2 mm when the foil thickness of the sample is 0.05 mm or less, and L=5 mm and d=4 mm when the foil thickness is more than 0.05 mm. Again, the amount of aging is The resolution of 0.01 mm was measured and was judged to be <0.01 mm when no aging was detected.

The arithmetic mean roughness (Ra) of the work rolls was determined by the above-described measurement method using a contact type roughness measuring machine.

The test results are shown in Table 1. The case where the cold rolling 3 is not performed is described as "none".

Inventive Examples 1 to 32 within the predetermined range of the present invention can obtain a 0.2% proof stress of 1100 MPa or more and a surface roughness of 0.1 μm or less, and the aging amount thereof is as small as 0.1 mm or less, and good characteristics can be obtained.

In Comparative Examples 1 and 2 in which the rolling reduction ratio of cold rolling 2 is less than 55%, the comparative examples 3 and 4 in which the temperature of the aging treatment is outside the range of 200 to 450 ° C, and the time of the aging treatment are outside the range of 2 to 20 hours. Comparative Examples 5 and 6 and Comparative Examples 7 and 8 in which the rolling reduction ratio of cold rolling 3 was less than 35% were 0.2% to ensure that the stress was less than 1100 MPa, and the aging amount thereof was more than 0.1 mm.

In the final pass of cold rolling 3, the surface roughness Ra of Comparative Examples 9 to 11 having a work roll having a roughness of more than 0.1 μm was more than 0.1 μm, and the aging amount thereof was more than 0.1 mm.

The 0.2% proof stress of Comparative Example 12 in which the Ti concentration was less than 1.5% by mass was less than 1100 MPa, and the aging amount thereof exceeded 0.1 mm. On the other hand, in Comparative Example 13 in which the Ti concentration exceeded 5.0% by mass, Comparative Example 14 in which the total amount of the additive elements other than Ti exceeded 1.0% by mass was broken during rolling and could not be evaluated.

Further, the 0.2% proof stress of Comparative Example 15 which was not subjected to pickling and polishing after the aging treatment was less than 1100 MPa, the surface roughness exceeded 0.1 mm, and the aging amount thereof exceeded 0.1 mm.

Claims (8)

A titanium copper foil containing 1.5 to 5.0% by mass of Ti and containing a total amount of 0 to 1.0% by mass of Ag, B, Co, Fe, Mg, Mn, Mo, Ni, P, Si, Cr and Zr One or more types, the remainder is composed of copper and unavoidable impurities, and the 0.2% proof stress in the direction parallel to the rolling direction is 1100 MPa or more, and the arithmetic mean roughness (Ra) in the direction perpendicular to the rolling direction It is 0.1 μm or less. The titanium copper foil according to claim 1, wherein the 0.2% guaranteed stress is 1200 MPa or more. A titanium copper foil according to claim 1 or 2, wherein the foil thickness is 0.1 mm or less. A method for producing a titanium copper foil, comprising: preparing 1.5 to 5.0% by mass of Ti, and containing a total amount of 0 to 1.0% by mass of Ag, B, Co, Fe, Mg, Mn, Mo, Ni, P, Si One or more of Cr and Zr, and the remainder consisting of ingots composed of copper and unavoidable impurities, and the ingots are sequentially hot-rolled and cold-rolled, and then sequentially carried out at 700 to 1000 ° C. 5 seconds to 30 minutes of solution treatment, cold rolling with a rolling reduction of 55% or more, aging treatment at 200 to 450 ° C for 2 to 20 hours, final cold rolling of a rolling reduction ratio of 35% or more, and by having 0.1 The work rolls of the arithmetic mean roughness (Ra) below μm are rolled in the final pass of the final cold rolling. A copper-clad product having the titanium copper foil of any one of claims 1 to 3. An electronic machine part having the titanium copper foil of any one of claims 1 to 3. For example, the electronic machine parts of the sixth application of the patent scope, wherein the electronic machine parts are auto focus camera modules. An autofocus camera module having a lens; a spring member that elastically presses the lens to an initial position in an optical axis direction; and an electromagnetic driving means that generates a bullet that resists the spring member The above-mentioned lens can be driven in the optical axis direction by the electromagnetic force of the pressure; and the above-mentioned spring member is the titanium copper foil according to any one of the above claims.