KR20150034275A - High-strength titanium-copper foil, and method for producing same - Google Patents

Abstract

There is provided a high strength titanium copper foil suitable as a conductive spring material for electronic parts such as an autofocus camera module. By mass, 1.5 to 5.0% by mass of Ti, the balance of copper and inevitable impurities, 0.2% proof stress in a direction parallel to the rolling direction of 1100 MPa or more, and arithmetic mean A titanium copper foil having a roughness (Ra) of 0.1 탆 or less.

Description

TECHNICAL FIELD [0001] The present invention relates to a high-strength titanium copper foil,

The present invention relates to a Cu-Ti alloy foil having excellent strength, which is preferable as a conductive spring material for an autofocus camera module and the like.

An electronic component called an autofocus camera module is used in the camera lens portion of the cellular phone. The autofocus function of the camera of the cellular phone is designed to move the lens in a certain direction by the spring force of the material used in the autofocus camera module, Move it in the direction opposite to the direction in which the spring force acts. The camera lens is driven by such a mechanism and the autofocus function is exhibited (for example, Patent Documents 1 and 2).

Therefore, the copper alloy foil used in the autofocus camera module needs a strength enough to withstand the deformation of the material due to the electromagnetic force. If the strength is low, the material can not stand the displacement due to the electromagnetic force, and permanent deformation (drowsiness) occurs. When the camera falls down, the lens can not move to a desired position when a constant current is applied, so that the autofocus function is not exercised.

A Cu-Ni-Sn based copper alloy foil having a thickness of 0.1 mm or less and having a 0.2% proof strength of 1100 MPa or more has been used for the autofocus camera module. However, recent demand for cost reduction has led to the use of titanium copper, which has a relatively lower material price than that of Cu-Ni-Sn based copper alloy, and its demand is increasing.

On the other hand, the strength of the titanium copper foil is lower than that of the Cu-Ni-Sn-based copper alloy foil, and there is a problem that the copper foil tends to settle down. As a technique for improving the strength of titanium copper, Patent Document 3 discloses a method of adjusting the average crystal grain size by final recrystallization annealing, followed by cold rolling and aging treatment in sequence, and in Patent Document 4, , Aging treatment and cold rolling are sequentially carried out. In Patent Document 5, a solution treatment is carried out in which hot rolling and cold rolling are carried out and then the temperature is maintained at 750 to 1000 ° C for 5 seconds to 5 minutes, A method of adjusting the X-ray diffraction intensity of {420} on the plate surface by sequentially performing cold rolling at a rolling rate of 0 to 50%, aging treatment at 300 to 550 DEG C, and finish cold rolling at a rolling rate of 0 to 30% In Patent Document 6, the first solution treatment, the intermediate rolling, the final solution treatment, the annealing, the final cold rolling, and the aging treatment are sequentially performed under predetermined conditions to obtain a {22 0} of the X-ray diffraction intensity is adjusted.

Japanese Laid-Open Patent Publication No. 2004-280031 Japanese Laid-Open Patent Publication No. 2009-115895 Japanese Patent Publication No. 4001491 Japanese Patent Publication No. 4259828 Japanese Patent Application Laid-Open No. 2010-126777 Japanese Laid-Open Patent Publication No. 2011-208243

In the examples and comparative examples of Patent Documents 3 to 6, a few titanium copper having a 0.2% proof stress of 1100 MPa or more is also seen. However, in the case of the conventional technique, if the thickness is as thin as 0.1 mm or less, when the load is applied to the material and the material is deformed after the load is removed, drowsiness occurs, It can not be used as a conductive spring material.

Therefore, it is an object of the present invention to provide a high strength titanium copper foil suitable as a conductive spring material for use in an electronic device component such as an autofocus camera module. It is another object of the present invention to provide a method for producing such a titanium copper foil.

The inventors of the present invention have found that the relationship between the 0.2% proof stress and the drowsiness of the copper foil and the relationship between the surface roughness and the drowsiness of the titanium copper foil show that the 0.2% proof stress is high and the surface roughness is small. The present invention has been completed based on the above findings, and is specified by the following.

(1) A steel ingot comprising 1.5 to 5.0 mass% of Ti, the balance consisting of copper and inevitable impurities, having a 0.2% proof stress in a direction parallel to the rolling direction of 1100 MPa or more, Wherein the arithmetic mean roughness (Ra) of the copper foil is 0.1 占 퐉 or less.

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

(3) A titanium copper foil of (1) or (2) having a thickness of 0.1 mm or less.

(4) Any one of (1) to (3) containing 0 to 1.0 mass% of at least one of Ag, B, Co, Fe, Mg, Mn, Mo, Ni, P, Si, Of titanium copper.

(5) An ingot containing 1.5 to 5.0 mass% of Ti and the remainder of copper and inevitable impurities is prepared. The ingot is subjected to hot rolling and cold rolling in this order, A cold rolling process at a reduction rate of 55% or more, an aging process at 200 to 450 ° C for 2 to 20 hours, and a final cold rolling process at a reduction rate of 35% or more. To a work roll having an arithmetic mean roughness (Ra) of 0.1 占 퐉 or less.

(6) The titanium copper foil of (5), wherein the ingot contains at least one of Ag, B, Co, Fe, Mg, Mn, Mo, Ni, P, Si, Cr and Zr in a total amount of 0 to 1.0 mass% Gt;

(7) A new item having a titanium copper foil according to any one of (1) to (4).

(8) An electronic device part having a titanium copper foil according to any one of (1) to (4).

(9) The electronic device parts of (8) in which the electronic device part is an autofocus camera module.

(10) a lens, a spring member for elastically supporting the lens at an initial position in the direction of the optical axis, and an electromagnetic drive means for generating an electromagnetic force against the elastic force of the spring member to drive the lens in the optical axis direction And the spring member is the titanium copper foil according to any one of (1) to (4).

It is possible to obtain a high strength Cu-Ti alloy foil preferable as a conductive spring material used for electronic parts such as an autofocus camera module.

1 is a sectional view showing an autofocus camera module according to the present invention.
2 is an exploded perspective view of the autofocus camera module of FIG.
3 is a sectional view showing the operation of the autofocus camera module of FIG.
4 is a schematic diagram showing a method for measuring the volume of the drowsiness.

(1) Ti concentration

In the titanium copper foil according to the present invention, the Ti concentration is 1.5 to 5.0 mass%. Titanium copper improves strength and conductivity by dissolving Ti in a Cu matrix by solution treatment and dispersing fine precipitates in an alloy by aging treatment.

When the Ti concentration is less than 1.5% by mass, precipitation of the precipitate becomes insufficient and the desired strength is not obtained. When the Ti concentration exceeds 5.0 mass%, the workability is deteriorated and the material tends to be cracked at the time of rolling. In consideration of the balance of strength and workability, the preferred Ti concentration is 2.9 to 3.5 mass%.

(2) Other added elements

In the titanium copper foil according to the present invention, by containing at least one of Ag, B, Co, Fe, Mg, Mn, Mo, Ni, P, Si, Cr and Zr in a total amount of 0 to 1.0 mass% Can be improved. The total content of these elements is 0, that is, these elements may not be contained. The upper limit of the total content of these elements is set to 1.0% by mass, because if it exceeds 1.0% by mass, the workability is deteriorated and the material tends to be cracked at the time of rolling. Considering balance between strength and workability, it is preferable that at least one of the above elements is contained in a total amount of 0.005 to 0.5 mass%.

(3) 0.2% proof stress

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

The upper limit of the 0.2% proof stress is not particularly restricted in terms of the intended strength of the present invention, but because of the labor and cost, the 0.2% proof strength of the titanium copper foil according to the present invention is generally 2000 MPa or less, 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 Z 2241 (metal material tensile test method).

(4) Surface roughness (Ra)

Generally, the thickness of the conductive spring material used in an autofocus camera module or the like is 0.1 mm or less. When a load is applied to a material, the stress is concentrated on the thinnest part of the material. If the surface roughness of the material is large, in other words, if thick and thin portions of the material are locally present, the stress is concentrated on the thin portion and the recession occurs. On the other hand, if the surface roughness of the material is small, even when a load is applied to the material, the stress does not concentrate well in a specific place, so that the recession does not occur easily.

According to the examination results of the present inventors, it has been found that when the arithmetic mean roughness (Ra) is controlled to 0.1 탆 or less, the drowsiness is significantly improved. Therefore, the arithmetic mean roughness (Ra) of the titanium copper foil according to the present invention is 0.1 占 퐉 or less, preferably 0.08 占 퐉 or less, and more preferably 0.06 占 퐉 or less. The lower limit of the surface roughness is not particularly restricted in terms of the intended strength of the present invention. However, arithmetic mean roughness Ra is 0.01 mu m or more in a typical embodiment, and 0.02 mu m or more in a more typical embodiment, because it is laborious and costly to make an extremely small arithmetic average roughness Ra.

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

(5) Thickness of copper foil

In one embodiment of the titanium copper foil according to the present invention, the thickness is 0.1 mm or less, in a typical embodiment the thickness is 0.08-0.03 mm, and in a more typical embodiment the thickness is 0.05-0.03 mm.

(6) Manufacturing method

In the process for producing a titanium copper foil according to the present invention, a raw material such as electric copper and Ti is first dissolved in a melting furnace to obtain a molten metal having a desired composition. Then, the molten metal is cast into an ingot. In order to prevent the titanium oxide from being abraded, the dissolution and casting are preferably 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 carried out in this order to finish with foil having desired thickness and characteristics.

The conditions of the hot rolling and the subsequent cold rolling 1 may be carried out under customary conditions in the production of titanium copper, and there is no particular requirement. The solution treatment may also be carried out under conventional conditions, for example, at 700 to 1000 ° C for 5 seconds to 30 minutes.

In order to obtain the above-described strength, it is desirable that the reduction rate of the cold-rolled 2 is defined as 55% or more. It is more preferably 60% or more, and still more preferably 65% or more. When the reduction rate is less than 55%, it is difficult to obtain a 0.2% proof stress of 1100 MPa or more. The upper limit of the reduction rate is not specifically defined in terms of the intended strength of the present invention, but it is not exceeded industrially to be 99.8%.

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

It is preferable that the reduction rate of the cold rolling 3 is set to 35% or more. , More preferably not less than 40%, further preferably not less than 45%. When the 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 reduction rate is not specifically defined in terms of the intended strength of the present invention, but it is not exceeded industrially to be 99.8%.

In order to obtain the above-described surface roughness, it is preferable to use a work roll having an arithmetic average roughness (Ra) of 0.1 占 퐉 or less, preferably 0.08 占 퐉 or less, more preferably 0.06 占 퐉 or less in the final pass of the cold- It is important. If the arithmetic average roughness of the work roll exceeds 0.1 mu m, the surface roughness of the material tends to exceed 0.1 mu m. However, arithmetic mean roughness (Ra) is 0.01 mu m or more in a typical embodiment, and 0.02 < / RTI > in a more typical embodiment, since it is laborious and costly to make an extremely small arithmetic mean roughness (Ra) Mu m or more.

In the present invention, an arithmetic average roughness Ra of the work roll is taken with respect to the longitudinal direction, that is, with respect to the direction corresponding to the direction perpendicular to the rolling direction of the above-described material, , According to JIS B 0601.

As the roughness of the work roll of the rolling becomes smaller, the material during rolling tends to slip and an abnormality such as breakage or winding deviation easily occurs. Unless there is a special reason, the larger the roughness of the work roll used for rolling, Do. Therefore, also in the present invention, it is preferable to use a work roll having an arithmetic mean roughness (Ra) of not more than 0.1 탆 only in the final pass of the cold-rolled steel sheet 3.

In the case of a production method in which heat treatment, pickling or buff polishing is performed after final rolling such as titanium copper, the surface quality depends on the buff polishing, and therefore the arithmetic average roughness Ra of the work roll used for rolling is 0.13 탆 or more It is common. Therefore, as far as the present inventor knows, the use of the low-intensity work roll as described above has not heretofore been practiced.

Generally, after the aging treatment, the surface is pickled or polished to remove the surface oxide film formed at the aging time. In the present invention, the surface may be pickled or polished after the aging treatment. Alternatively, low-temperature annealing may be performed after cold-rolling 3, and then the surface may be pickled or polished to remove the surface oxide film formed at the time of low-temperature annealing. However, in this case, the effect of the present invention is not exerted unless the surface roughness after polishing is within the specified range of the present invention. Since the roughness of the buff used for polishing is large in the conventional polishing for removing the oxide film, a smooth surface at the level specified in the present invention is not obtained. In order to obtain the surface roughness defined by the present invention by polishing, it is necessary to study such as reducing the roughness of the buff.

(7) Usage

The titanium copper foil according to the present invention can be preferably used as a material for parts for electronic devices such as switches, connectors, jacks, terminals, relays and the like, It can be preferably used as a conductive spring material. The autofocus camera module according to an embodiment includes a lens, a spring member for elastically supporting the lens at an initial position in the optical axis direction, and an electromagnetic force for resisting the elastic force of the spring member to drive the lens in the optical axis direction And an electronic drive means. The electromagnetic driving means includes, for example, a quadrangular cylindrical yoke, a coil accommodated inside the inner peripheral wall of the yoke, and a magnet accommodated inside the outer peripheral wall of the yoke with the coil surrounding the coil can do.

1 is an exploded perspective view of the autofocus camera module of FIG. 1, and FIG. 3 is a cross-sectional view of the autofocus camera module of FIG. 1, Sectional view.

The autofocus camera module 1 includes a yoke 2 having a U-shaped cylindrical shape, a magnet 4 mounted on an outer wall of the yoke 2, a carrier 5 having a lens 3 at a central position, A coil 6 mounted on the carrier 5, a base 7 on which the yoke 2 is mounted, a frame 8 for supporting the base 7, Spring members 9a and 9b, and two caps 10a and 10b covering the upper and lower portions. The two spring members 9a and 9b are identical to each other and support the carrier 5 from above and below in the same positional relationship and function as a feed path to the coil 6. [ By applying a current to the coil 6, the carrier 5 moves upward. In this specification, upper and lower wording is appropriately used, and the upper and lower sides in Fig. 1 indicate the positional relationship between the camera and the subject.

The yoke 2 is a magnetic substance such as soft iron and has an upper surface formed in a closed-C-shaped cylindrical shape and has a cylindrical inner wall 2a and an outer wall 2b. On the inner surface of the U-shaped outer wall 2b, a ring-shaped magnet 4 is attached (adhered).

The carrier 5 is a molded product made of synthetic resin or the like having a cylindrical structure having a bottom surface portion. The carrier 5 supports the lens at a central position, and the preformed coil 6 is mounted on the outer side of the bottom surface. The yoke 2 is inserted into the inner peripheral portion of the base 7 of the rectangular shaped resin molded article and the whole yoke 2 is further fixed with the frame 8 of the resin molded product.

The outer peripheral portions of the spring members 9a and 9b are fitted and fixed to the frame 8 and the base 7 respectively and the cutout grooves for every inner circumferential portion 120 ° are fitted to the carrier 5, .

The cap 10b is fixed to the bottom surface of the base 7 and the cap 10b is fixed to the bottom surface of the base 7 by the adhesive or thermal caulking between the spring member 9b and the base 7 and between the spring member 9a and the frame 8, The spring member 9a is mounted between the frame 7 and the cap 10b and the spring member 9b is mounted between the base 7 and the cap 10b and the spring member 9a is mounted between the frame 8 and the cap 10a, It is fixed by putting.

One lead wire of the coil 6 passes through the groove formed in the inner circumferential surface of the carrier 5 and extends upward and is soldered to the spring member 9a. The other lead wire passes through the groove formed in the bottom surface of the carrier 5 and extends downward, and is soldered to the spring member 9b.

The spring members 9a and 9b are leaf springs of the titanium copper foil according to the present invention. And has elasticity to elastically support the lens 3 to an initial position in the optical axis direction. At the same time, it also functions as a feed path for the coil 6. One point of the outer peripheral portion of the spring members 9a and 9b protrudes outward to function as a power supply terminal.

The cylindrical magnet 4 is magnetized in a radial direction and forms a magnetic path with the inner wall 2a, the upper surface portion and the outer wall 2b of the elliptic yoke 2 as a path And a coil 6 is disposed in a gap between the magnet 4 and the inner wall 2a.

Since the spring members 9a and 9b have the same shape and are mounted in the same positional relationship as shown in Figs. 1 and 2, the shaft misalignment when the carrier 5 moves upward can be suppressed. Since the coil 6 is manufactured by press-molding after winding, the accuracy of the finishing outer diameter is improved, and the coil 6 can be easily arranged in a predetermined narrow gap. Since the carrier 5 hits the base 7 at the lowermost position and strikes the yoke 2 at the uppermost position, the carrier 5 is provided with a biasing force mechanism in the up and down direction, thereby preventing the carrier 5 from falling off.

Fig. 3 shows a cross-sectional view when a current is applied to the coil 6 and the carrier 5 having the lens 3 for autofocus is moved upward. When power is applied to the power supply terminals of the spring members 9a and 9b, a current flows to the coil 6, and an electromagnetic force upwardly acts on the carrier 5. [ On the other hand, the restoring force of the two spring members 9a, 9b connected to the carrier 5 acts downward. Therefore, the upward movement distance of the carrier 5 becomes a position where the electromagnetic force and the restoring force are balanced. In this way, the amount of movement of the carrier 5 can be determined by the amount of current applied to the coil 6.

Since the upper spring member 9a supports the upper surface of the carrier 5 and the lower spring member 9b supports the lower surface of the carrier 5, the restoring force is uniformly lowered from the upper surface and the lower surface of the carrier 5 And the axial misalignment of the lens 3 can be suppressed to a small degree.

Therefore, when the carrier 5 is moved upward, a guide by a rib or the like is not necessary and is not used. Since there is no sliding friction due to the guide, the amount of movement of the carrier 5 is controlled purely by the balance of the electromagnetic force and the restoring force, and the movement of the lens 3 is achieved smoothly and with high precision. This achieves autofocus with less lens shake.

Although the magnet 4 is described as being cylindrical, it is not limited to this, but is magnetized in the radial direction by dividing it into 3 to 4 parts and is affixed to the inner surface of the outer wall 2b of the yoke 2, .

Example

Examples of the present invention will now be described with reference to comparative examples, which are provided for better understanding of the present invention and its advantages, and are not intended to limit the invention.

The effects of alloy components and manufacturing conditions on 0.2% proof stress and drowsiness were investigated using alloys containing the alloying elements shown in Table 1 and the balance copper and inevitable impurities as experimental materials.

2.5 kg of electric copper was dissolved in a vacuum melting furnace, and an alloy element was added so that the alloy composition shown in Table 1 was obtained. This molten metal was poured into a cast iron mold to prepare 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 following process sequence to prepare a product sample having a predetermined thickness described in Table 1. [

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

(2) Grinding: The oxide scale produced by hot rolling was removed by a grinder. The thickness after grinding was 9 mm.

(3) Cold rolling 1: Rolled to a predetermined thickness according to the reduction ratio.

(4) Solution treatment: A sample was charged into an electric furnace heated to 800 DEG C, held for 5 minutes, and then the sample was placed in a water bath and quenched.

(5) Cold rolling 2: Rolled to a predetermined thickness according to the reduction ratio.

(6) Aging treatment: The mixture was heated in an Ar atmosphere at the temperature and time shown in Table 1. [ The temperature was chosen so that the tensile strength after aging was at a maximum.

(7) Pickling and buff polishing: Buffing was performed in an aqueous solution of 15 vol.% Sulfuric acid and 1.5 vol.% Peroxide in order to remove the oxide scale generated by the aging treatment.

(8) Cold Rolling 3: Rolled to the thickness shown in Table 1. In the final pass of the rolling, work rolls of the roughness shown in Table 1 were used.

The following evaluations were performed on the manufactured product samples.

(A) 0.2% Strength

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

(B) Surface roughness

The arithmetic average roughness (Ra) of the surface of the foil was determined by a confocal microscope HD-100 manufactured by Lasertec by the above-described measuring method. Measurements were made at right angles to the rolling direction.

(C) Depression

As shown in Fig. 4, one end of the sample was fixed, and at the position of distance L from the fixed end, a tip of the short sample was cut at the knife edge The machined punch was pressed at a moving speed of 1 mm / min to impart a warp of the distance d to the sample, and then the punch was returned to the initial position and removed. After the removal, the drowsiness (delta) was obtained.

The test conditions are L = 5 mm and d = 4 mm when the thickness of the sample is 0.05 mm or less, L = 3 mm, d = 2 mm, and the thickness is thicker than 0.05 mm. In addition, the drowsiness was measured with a resolution of 0.01 mm, and <0.01 mm when drowsiness was not detected.

The arithmetic mean roughness (Ra) of the work roll was obtained by the above-described measuring method using a contact type roughness meter.

Table 1 shows the test results. And the case where cold rolling 3 was not carried out was described as "none".

Inventive Examples 1 to 32 within the scope of the present invention obtained 0.2% proof stress of 1100 MPa or more and surface roughness of 0.1 占 퐉 or less, and their puddling volume was as small as 0.1 mm or less.

Comparative Examples 1 and 2 in which the rolling reduction of cold-rolled 2 is less than 55%, Comparative Examples 3 and 4 in which the aging temperature is outside the range of 200 to 450 ° C, Comparative Example 5 in which the aging time is out of the range of 2 to 20 hours, In Comparative Examples 7 and 8, in which the reduction ratio of cold rolling 3 to cold rolling 3 was less than 35%, the 0.2% proof stress was less than 1100 MPa, and the pit volume thereof exceeded 0.1 mm.

In the final pass of the cold rolling 3, the surface roughnesses Ra of Comparative Examples 9 to 11 using work rolls having an illuminance exceeding 0.1 占 퐉 exceeded 0.1 占 퐉 and their diurnal volume exceeded 0.1 mm.

The 0.2% proof stress of Comparative Example 12 in which the Ti concentration was less than 1.5 mass% was less than 1100 MPa, and the dead volume exceeded 0.1 mm. On the other hand, in Comparative Example 13 in which the Ti concentration exceeded 5.0 mass%, and in Comparative Example 14 in which the total amount of the additional elements other than Ti exceeded 1.0 mass%, cracking occurred during rolling and evaluation could not be made.

The 0.2% proof stress of Comparative Example 15 in which cold rolling 3 was not performed after pickling and buff polishing after the aging treatment was less than 1100 MPa, the surface roughness was more than 0.1 mm, the dwelling volume was more than 0.1 mm Respectively.

[Table 1-1]

[Table 1-2]

1: Auto focus camera module
2: York
3: Lens
4: Magnet
5: Carrier
6: Coil
7: Base
8: Frame
9a: an upper spring member
9b: a lower spring member
10a, 10b: cap

Claims (8)

1.5 to 5.0% by mass of Ti and 0 to 1.0% by mass of at least one of Ag, B, Co, Fe, Mg, Mn, Mo, Ni, P, Si, Cr and Zr in a total amount, Wherein the 0.2% proof stress in the direction parallel to the rolling direction is 1100 MPa or more and the arithmetic average roughness Ra in the direction perpendicular to the rolling direction is 0.1 占 퐉 or less, the copper foil being made of copper and unavoidable impurities. The method according to claim 1,
Wherein the 0.2% proof strength is 1,200 MPa or more. 3. The method according to claim 1 or 2,
A titanium copper foil having a thickness of 0.1 mm or less. 1.5 to 5.0% by mass of Ti and 0 to 1.0% by mass of at least one of Ag, B, Co, Fe, Mg, Mn, Mo, Ni, P, Si, Cr and Zr in a total amount, Copper, and inevitable impurities, and hot rolling and cold rolling are successively performed on the ingot, followed by a solution treatment at 700 to 1000 占 폚 for 5 seconds to 30 minutes, a cold rolling with a reduction ratio of 55% or more Aging treatment at 200 to 450 DEG C for 2 to 20 hours and final cold rolling at a reduction ratio of 35% or more are carried out successively, and the final pass of the final cold rolling is performed with a work roll having an arithmetic mean roughness Ra of 0.1 m or less Wherein the copper foil is rolled. A new article having the titanium copper foil according to any one of claims 1 to 3. An electronic device part having the titanium copper foil according to any one of claims 1 to 3. The method according to claim 6,
An electronic device part in which the electronic device part is an autofocus camera module. A spring member for elastically supporting the lens at an initial position in the direction of the optical axis, and an electronic driving means for generating an electromagnetic force against the elastic force of the spring member to drive the lens in the optical axis direction , And the spring member is the titanium copper foil according to any one of claims 1 to 3.

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