KR20190032328A - Titanium copper foil, wrought copper, electric parts and auto focus camera module - Google Patents

Abstract

Provided are a titanium copper foil and a manufacturing method thereof, wherein the thin titanium copper foil of which a thickness is less than 0.1 μm has excellent soldering wetting property and soldering adhering strength to be appropriately used for electric parts such as an auto focus camera module or the like as a conductive spring material. According to the present invention, a thickness of the titanium copper foil is less than 0.1 mm, and the titanium copper foil comprises: 1.5-4.5 mass% of Ti; and the remainder consisting of copper and inevitable impurities. The maximum height roughness (Rz) of a surface is 0.1-1 μm in a direction parallel with a rolling direction.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a titanium copper foil, a copper foil,

The present invention relates to a titanium copper foil, an elongated copper product, an electronic device part, and an autofocus camera module. More particularly, the present invention relates to a copper foil which is suitable for use as a conductive spring material such as an autofocus camera module, -Type copper alloy foil.

An electronic component called an autofocus camera module is used in the camera lens portion of the cellular phone. The autofocus function of a cellular phone camera is a function of operating the lens in a certain direction by the spring force of the material used in the autofocus camera module and by applying an electric current generated by flowing a current through a coil wound around the lens, Act in the direction opposite to the direction in which the spring force acts. In such a mechanism, the camera lens is driven and the autofocus function is exercised.

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

Regarding Cu-Ti based copper alloy foils of this type, for example, in Patent Document 1, when the thickness is as thin as 0.1 mm or less, there is a problem that deformation occurs when a load is applied to a material and then the load is removed . In order to solve this problem, Patent Document 1 discloses that "a steel sheet having a thickness of 0.1 mm or less, containing 1.5 to 4.5 mass% of Ti, the balance being made of copper and unavoidable impurities, and having a thickness in the direction parallel to the rolling direction of 0.2 % Proof stress is 1100 MPa or more and the arithmetic mean roughness (Ra) in a direction perpendicular to the rolling direction is 0.1 占 퐉 or less ".

However, since Cu-Ti alloy is extremely active and contains Ti which is an easily oxidizable element, a strong oxide film is produced in the aging treatment as a final step. Such a strong oxide film remarkably deteriorates the solderability. Therefore, in a Cu-Ti alloy having a relatively thick thickness such as a titanium copper plate, a copper alloy, etc., as described in Patent Document 2, (Acid cleaning), or mechanical polishing is performed to remove the oxide film.

To remove the oxide film with a Cu-Ti alloy, first perform chemical polishing. Since the oxide film of a Cu-Ti alloy containing titanium oxide is extremely stable against an acid, it is necessary to use a chemical polishing liquid having a very high corrosive power such as a solution obtained by mixing hydrogen peroxide with hydrofluoric acid or sulfuric acid in chemical polishing.

However, when a chemical polishing liquid having such an extremely strong corrosive force is used, not only the oxide film but also the unoxidized portion may be corroded, and uneven irregularities or discoloration may occur on the surface after chemical polishing. In addition, corrosion may not proceed uniformly, and the oxide film may remain locally. Therefore, after the chemical polishing is performed to remove the unevenness, discoloration, and residual oxide film on the surface, mechanical polishing is performed using, for example, a buff or the like.

After machine polishing, rust-preventive treatment is performed as final surface treatment to obtain plate and plate products. As for the rust-proofing treatment of titanium copper foil, an aqueous solution of benzotriazole (BTA) is used in the same manner as that used for copper plating and copper alloy plating.

Patent Document 1: Japanese Patent Publication No. 5723849 Patent Document 2: Japanese Patent Publication No. 4068413

However, unlike the case of the titanium copper plating bath, it is difficult to perform the mechanical polishing for improving the solderability by removing the oxide film produced in the aging treatment, for example, in the titanium copper foil having a thickness of 0.1 탆 or less . The reason for this is twofold, the first relates to the foil of the mechanical polishing line, and the second relates to the plate thickness control in the mechanical polishing line.

Regarding the overrun of the mechanical polishing line, which is the first reason, when the buff is used, the buff is caught by the titanium copper foil in accordance with the rotation of the buff roll, and sometimes the titanium copper foil is broken from the caught portion. The buff polishing is to rotate the center axis of the circumferential buff roll to polish the surface of the titanium copper foil. The buff roll is obtained by fixing a resin in which abrasive grains (abrasive grains such as SiC) are dispersed to sponge-like organic fibers. The resin agglomerates hang on a large irregularity at the edge of the titanium copper foil, and a tension exceeding the strength of the titanium copper foil If it works, it breaks.

As for the second reason, in regard to the plate thickness control in the mechanical polishing line, a pressing load is applied to the circumferential buff roll in order to polish it, and a tension is applied to the titanium copper foil in order to pass the line. These push-down loads and tensile forces have oscillations with more or less periodicity, and this vibration is called chaattering. Depending on the vibration period of the chattering, there may be a case where each vibration resonates. In the case where the resonance is large, a tatami-like shape appears on the polishing surface of the object to be polished by chattering. The shape created by chattering is called chatter marks. This indicates that the polishing amount is different depending on the shape, that is, the polishing amount of the titanium copper foil is scattered. Here, in the case of the titanium copper foil, since the thickness is thinner than that of the titanium copper plate, the influence of the difference in the amount of polishing is large. That is, when the titanium copper foil is buffed, variation in thickness becomes large, and when it is used as a spring, the spring characteristic becomes irregular, which is not preferable.

Therefore, it is difficult to mechanically polish a titanium copper foil having a thinner thickness than a titanium copper plating bath by using a buff or the like. Therefore, it is difficult to effectively remove the oxide film by chemical polishing and mechanical polishing such as titanium copper plating Do. In addition, in recent years, lead-free soldering has been widely used for health reasons, and the lead-free soldering has a lower solderability than conventional lead-containing soldering.

As a result, there is a problem in that the titanium copper foil having a thin thickness does not negate the deterioration of the solderability, and in particular, the solder wettability and solder adhesion required when the autofocus camera module is manufactured can not be ensured.

Disclosure of the Invention The present invention has been made to solve such a problem, and it is an object of the present invention to provide a titanium copper foil having a thickness of 0.1 占 퐉 or less and excellent in solder wettability and solder adhesion strength, The present invention also provides a titanium copper foil suitable for use as a material and a method for producing the same.

As a result of intensive investigation, the inventors have found that by adjusting the maximum height roughness (Rz) of the surface in a direction parallel to the rolling direction with a titanium copper foil having a thickness of 0.1 mm or less to a predetermined range, Wettability can be ensured and a high adhesion strength based on the so-called anchor effect can be exhibited. The surface roughness Rz can be changed by forming an oil pit by rolling so as to control the degree of processing of the final cold rolling at the time of producing the titanium copper foil, It is possible to produce a titanium copper foil having a roughness (Rz).

Under these insights, the titanium copper foil of the present invention has a thickness of 0.1 mm or less, contains 1.5 to 4.5% by mass of Ti, the balance of copper and unavoidable impurities, and has a maximum roughness of the surface in the direction parallel to the rolling direction (Rz) of 0.1 占 퐉 to 1 占 퐉.

Here, the titanium copper foil of the present invention preferably has a tensile strength of 1100 MPa or more.

The titanium copper foil of the present invention may contain 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% .

The novelty product of the present invention comprises any one of the titanium copper foils.

The electronic device part of the present invention comprises any one of the above titanium copper foils.

This electronic device part is preferably an autofocus camera module.

The autofocus camera module of the present invention comprises a lens, a spring member for resiliently biasing the lens at an initial position in the direction of the optical axis, and an electromagnetic drive for driving the lens in the optical axis direction by generating an electromagnetic force against the biasing force of the spring member And the spring member is any one of titanium copper foils.

According to the present invention, by setting the maximum height roughness (Rz) of the surface in the direction parallel to the rolling direction to 0.1 to 1 mu m, it is possible to provide a titanium copper foil excellent in solderability and adhesion strength. These titanium copper foils are particularly suitable for electronic component parts, particularly autofocus camera module applications.

1 is a sectional view showing an autofocus camera module according to an embodiment of 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.

Hereinafter, embodiments of the present invention will be described in detail.

The titanium copper foil of one embodiment of the present invention has a thickness of 0.1 mm or less, contains 1.5 to 4.5% by mass of Ti, the balance of copper and unavoidable impurities, and has a maximum height of the surface in the direction parallel to the rolling direction And the roughness (Rz) is 0.1 탆 to 1 탆.

(Ti concentration)

In the titanium copper foil of the present invention, the Ti concentration is 1.5 to 4.5% by mass. Titanium copper solves the Ti in the Cu matrix by solution treatment and disperses fine precipitates in the alloy by aging treatment, thereby increasing strength and conductivity.

When the Ti concentration is less than 1.5% by mass, precipitation of the precipitates becomes insufficient and desired strength can not be obtained. If the Ti concentration exceeds 4.5 mass%, the workability is deteriorated, and the material tends to be broken 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%.

(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 further improved. The total content of these elements is 0, that is, these elements may not be included. The upper limit of the total content of these elements is set at 1.0% by mass, and if the content exceeds 1.0% by mass, the workability is deteriorated and the material tends to be broken at the time of hot rolling.

(The tensile strength)

The tensile strength required for the titanium copper foil suitable as the conductive spring material or the like of the autofocus camera module is 1100 MPa or more, preferably 1200 MPa or more, and more preferably 1300 MPa or more. In the present invention, the tensile strength in the direction parallel to the rolling direction of the titanium copper foil is measured, and the tensile strength is measured in accordance with JIS Z2241 (metal material tensile test method).

(Surface roughness)

The titanium copper foil of the present invention has a maximum height roughness (Rz) in a direction parallel to the rolling direction of its surface within a range of 0.1 to 1 mu m. This makes it possible to secure a predetermined excellent solderability and also to increase the adhesion strength by soldering, which is particularly advantageous in the case of being used for an autofocus camera module.

The reason why the maximum height roughness Rz in the direction parallel to the rolling direction is defined is that the surface roughness remarkably changes in the direction parallel to the rolling direction when the oil pit amount is large or small when rolling.

More specifically, if the roughness Rz in the rolling parallel direction is within the range of 0.1 to 1 占 퐉, the actual surface area is not so large that the solder tends to spread, and the solder has good irregularities and excellent solder adhesion. The maximum height roughness (Rz) in the direction perpendicular to the rolling direction is also preferably 0.1 to 1 占 퐉.

In other words, if the maximum surface roughness Rz in the direction parallel to the rolling direction is less than 0.1 mu m, the anchor effect can not be obtained and the adhesion is poor. On the other hand, when the maximum surface roughness (Rz) in a direction parallel to the rolling direction exceeds 1 탆, it takes much time for brazing and wetting, and the solder wettability is poor.

From this viewpoint, the maximum height roughness Rz of the surface in the direction parallel to the rolling direction is more preferably 0.1 占 퐉 to 0.4 占 퐉, and still more preferably 0.1 占 퐉 to 0.25 占 퐉.

The maximum height roughness Rz can be measured in accordance with JIS B0601 (2013) from the curve by taking a roughness curve having a reference length of 300 占 퐉 along a direction parallel or parallel to the rolling direction of the titanium copper foil .

(Thickness of copper foil)

The titanium copper foil of the present invention has a thickness of 0.1 mm or less, in a typical embodiment the thickness is 0.018 mm to 0.08 mm, and in a more typical embodiment the thickness is 0.02 mm to 0.05 mm.

(Manufacturing method)

In order to produce the above-mentioned titanium copper foil, first, a raw material such as copper and Ti is dissolved in a melting furnace to obtain a molten metal having a desired composition. Then, the molten metal is cast in an ingot. The dissolution and casting are preferably carried out under vacuum or in an inert gas atmosphere in order to prevent the titanium from being oxidized. Thereafter, the ingot is typically subjected to hot rolling, first cold rolling, solution treatment, second cold rolling, aging treatment, and third cold rolling (final cold rolling) in this order to obtain a desired thickness and characteristics It is finished with a branch.

The conditions of the hot rolling and the first cold rolling thereafter are sufficient to be carried out under the conventional conditions in the production of the titanium copper, and there is no particular requirement here. The solution treatment may also be carried out at a temperature of 700 to 1000 占 폚 for 5 seconds to 30 minutes, although it is not limited to customary conditions.

In order to obtain the aforementioned strength, the reduction rate of the second cold rolling is preferably set to 55% or more. , More preferably at least 60%, even more preferably at least 65%. When the reduction rate is less than 55%, it becomes difficult to obtain a tensile strength 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 does not exceed 99.8% industrially.

The heating temperature for the aging treatment is 200 to 300 캜, and the heating time is 2 to 20 hours. When the heating temperature is lower than 200 占 폚, it becomes difficult to obtain a tensile strength of 1100 MPa or more. If the temperature exceeds 300 ° C, an excess oxide film is produced. If the heating time is less than 2 hours or more than 20 hours, it becomes difficult to obtain a tensile strength of 1100 MPa or more.

In order to obtain the titanium copper foil of the present invention, it is important to use a rolling mill having a small-diameter roll in the final cold rolling, to control the rolling reduction, and to roll the final pass with a work roll of a predetermined roughness.

Concretely, since the titanium copper foil is hardly cracked due to its high strength and rigid foil, it is preferable to use a rolling mill having a small-diameter roll having a diameter of 30 mm to 120 mm in the final cold rolling. If the roll diameter is too large, the titanium copper foil is not broken to the intended thickness, and there is a possibility that the oil puddle tends to occur because the amount of the rolling oil to be rolled increases at the time of rolling. If the roll diameter is too small, It is feared that the productivity is lowered. Therefore, it is more preferable to use a roll having a diameter of 40 mm to 100 mm.

In the final cold rolling, oil bits are formed on the foil surface, and the surface roughness (Rz) of the titanium copper foil to be produced is changed. Therefore, it is preferable to set the reduction ratio of the final pass to 9% to 35%. If the reduction rate is too large, the amount of the rolling oil to be rolled between the rolling roll and the material is reduced, so that the surface roughness (Rz) of the produced titanium copper foil becomes small, resulting in deterioration of solder adhesion. On the other hand, if the reduction rate is too small, the amount of the rolling oil to be rolled between the rolling roll and the material increases, so that the surface roughness Rz of the produced titanium copper foil increases and the solder wettability decreases. Therefore, the reduction rate of the final pass is more preferably 9% to 30%.

It is also effective to use a work roll made of die steel as the material of the work roll and an arithmetic mean roughness (Ra) of 0.1 mu m or less in the final pass. If the arithmetic mean roughness (Ra) of the work roll in the final pass is large, it can be considered that the surface roughness (Rz) of the material easily exceeds 1 탆. The arithmetic average roughness Ra of this work roll was obtained by taking roughness curves of a reference length of 400 mu m in the longitudinal direction, that is, in the direction corresponding to the direction perpendicular to the rolling direction of the above-mentioned material, .

Generally, after the heat treatment, the surface is pickled or polished to remove the oxide film or oxide layer formed on the surface. In the present invention, it is also possible to carry out pickling or polishing of the surface after the heat treatment. In addition, low temperature annealing may be performed after the second cold rolling.

After the final cold rolling, rustproofing treatment can be performed. This rust-preventive treatment can be carried out under the same conditions as those in the past, and an aqueous solution of benzotriazole (BTA) or the like can be used.

(Usage)

The titanium copper foil of the present invention can be used for various purposes, but it can be suitably used particularly as a component material for an electronic device such as a switch, a connector, a jack, a terminal, and a relay. Among them, It can be suitably used as a conductive spring material to be used.

The autofocus camera module includes, for example, a lens, a spring member for resiliently biasing the lens to an initial position in the optical axis direction, and an electromagnetic drive means for generating an electromagnetic force against the biasing force of the spring member, As shown in Fig. Here, the spring member may be made of the titanium copper foil of the present invention.

The electromagnetic driving means may include, for example, a U-shaped cylindrical yoke, a coil accommodated inside the inner peripheral wall of the yoke, and a magnet surrounding the coil and accommodated inside the outer peripheral wall of the yoke.

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

The autofocus camera module 1 includes a cylindrical shape yoke 2, a magnet 4 provided on an outer wall of the yoke 2, a carrier 5 provided with a lens 3 at a central position, A base 7 on which the yoke 2 is mounted; a frame 8 for supporting the base 7; two springs for supporting the carrier 5 up and down; And members (9a, 9b) and two caps (10a, 10b) covering the upper and lower sides. The two spring members 9a and 9b are of the same shape and hold the carrier 5 in the vertical position at 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 words are appropriately used, but upper and lower in Fig. 1, and the upper side shows a positional relationship from the camera to the subject.

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

The carrier 5 is a molded product made of a 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 fitted to the inner circumference of the base 7 of the spherical resin molded article and the yoke 2 is further fixed with the frame 8 of the molded resin product.

The outermost peripheral portions of the spring members 9a and 9b are fitted and fixed to the frame 8 and the base 7 respectively and the recessed portions of the inner peripheral portions 120 are engaged with the carrier 5 and fixed by heat caulking or the like.

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 and heat caulking between the spring member 9b and the base 7 and between the spring member 9a and the frame 8. Further, The spring member 9a is provided between the frame 7 and the cap 10b and the spring member 9b is provided between the base 7 and the cap 10b and the spring member 9a is provided between the frame 8 and the cap 10a, And is fixed.

One lead wire of the coil 6 is drawn upward through the groove provided in the inner peripheral surface of the carrier 5 and soldered to the spring member 9a. The other lead wire is extended downward through the groove provided in the bottom surface of the carrier 5 and soldered to the spring member 9b.

The spring members 9a and 9b are plate spring of titanium copper foil according to the present invention. The lens 3 is resiliently biased to the initial position in the optical axis direction with the spring property. At the same time, it functions as a feed path to the coil 6. One portion 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 the radial direction and forms a magnetic path with the inner wall 2a, the upper face portion and the outer wall 2b of the U-shaped yoke 2 as a path, And a coil 6 is disposed in a gap between the inner wall 2a and the inner wall 2a.

Since the spring members 9a and 9b have the same shape and are provided in the same positional relationship as shown in Figs. 1 and 2, the axial misalignment when the carrier 5 moves upward can be suppressed. Since the coil 6 is manufactured by pressure molding after winding, the accuracy of the finished outer diameter is improved, and the coil 6 can be easily arranged in a predetermined narrow gap. The carrier 5 contacts the base 7 at the lowermost position and touches the yoke 2 at the uppermost position. Therefore, the carrier 5 is provided with a mechanism that tilts in the vertical 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 is moved upward for autofocusing. When power is applied to the power supply terminals of the spring members 9a and 9b, an electric current flows in the coil 6, and an electromagnetic force is applied to the carrier 5 upward. On the other hand, the restoring force of the two spring members 9a, 9b connected to the carrier 5 acts downward. Therefore, the moving distance to the upper side of the carrier 5 becomes a position in which the electromagnetic force and the restoring force are balanced. Thus, 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 lower surface of the carrier 5 And the axial misalignment of the lens 3 can be suppressed to a small degree.

Therefore, in the upward movement of the carrier 5, 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 dominated by a balance between the electromagnetic force and the restoring force, and smooth and precise movement of the lens 3 is realized. This achieves autofocus with little lens shift.

Although the magnet 4 has been described as a cylindrical shape, it is not limited thereto. It may be magnetized in three to four divisions in the radial direction and adhered to the inner surface of the outer wall 2b of the yoke 2 by adhesion.

Example

Next, the titanium copper foil of the present invention was started and its effect was confirmed. It should be understood, however, that the description herein is for illustrative purposes only and is not intended to be limiting.

<Manufacturing Conditions>

The prototype manufacturing was carried out as follows. First, 2.5 kg of electric copper was dissolved in a vacuum melting furnace, and Ti was added so as to obtain a predetermined concentration of Ti. This molten metal was poured into a cast iron mold to produce an ingot having a thickness of 30 mm, a width of 60 mm and a length of 120 mm.

The ingot was heated at 950 占 폚 for 3 hours, and hot-rolled to a thickness of 10 mm was carried out. The oxide scale generated in the hot rolling was removed by a grinder to perform grinding. The thickness after the grinding was 9 mm. Then, the first cold rolling was carried out and the steel sheet was rolled to a thickness of 1 mm. In the subsequent solution treatment, the sample was placed in an electric furnace kept at a temperature of 800 ° C for 5 minutes, and then the sample was placed in a water bath and quenched. Then, the second cold rolling was carried out, and the steel was rolled to a thickness of 0.04 mm at a reduction ratio of 96%. Thereafter, it was heated at 280 DEG C for 10 hours as an aging treatment. Here, the temperature of the aging treatment was selected so as to maximize the tensile strength after aging. Thereafter, the third cold rolling was not carried out under the conditions shown in Table 1.

The following evaluations were carried out on the prototype thus produced.

<Surface roughness>

A roughness curve having a reference length of 300 mu m was taken along the direction parallel to the rolling direction of the prototype, and the roughness curve was measured from the curve in accordance with JIS B0601 (2013).

<Solder wettability and solder adhesion>

Soldering test was carried out using soldering of Pb-free soldering M705 system made of Senju metal. In the evaluation of the solder wettability, the blurring diameter of 1.5 mm or more was evaluated as &amp; cir &amp; and the blurring diameter of less than 1.5 mm was evaluated as x, and the measurement was carried out by a solder checker (SAT-2000 manufactured by Rescan Co., Ltd.) according to JIS C60068-2-54 And the appearance of the soldered portion was observed. The measurement conditions are as follows. The sample was degreased with acetone as a pretreatment. Next, pickling was carried out using a 10 vol% sulfuric acid aqueous solution. The test temperature of soldering was 245 ± 5 ℃. The flux is not specially specified, but GX5 manufactured by Asahi Chemical Industry Co., Ltd. was used. The immersion depth was 2 mm, the immersion time was 10 seconds, the immersion speed was 25 mm / second, and the sample width was 10 mm. The evaluation standard was visually observed with a 20-times stereomicroscope to determine whether the entire surface of the soldering portion was covered with solder (good), and whether a part or whole surface of the soldering portion was not covered with solder was evaluated as poor (poor). In the evaluation of the solder adhesion, the peel strength of 1N or more was evaluated as &amp; cir &amp; and the peel strength was evaluated as less than 1N. The peel strength was measured by using a lead-free solder (Sn-3.0 mass% Ag-0.5 mass% Cu (mass%)) of titanium copper foil having a plated layer and a pure copper foil (alloy No. C1100 specified by JIS H3100 ). The copper copper foil was made of a short rectangular having a width of 15 mm and a length of 200 mm and a copper foil of a short rectangular shape having a width of 20 mm and a length of 200 mm and having a center portion of 30 mm x 15 mm in the longitudinal direction, 0.02 mm, length: 120 ± 1 mm) is placed so as to be within the above-mentioned area, and then the bonding temperature is 245 ° C ± 5 ° C. After bonding, the 180 degree peel test is carried out at a rate of 100 mm / min to measure the adhesion strength. The average value of the load (N) in a section of 40 mm from 30 mm to 70 mm of the peeling displacement is taken as the adhesion strength. An example of measurement results in the solder adhesion strength test is shown in Fig.

[Table 1]

In Examples 1 to 22 of the present invention, maximum roll roughness (Rz) in the rolling parallel direction is 0.1 to 1.0 (mm) because the final pass is set to a predetermined reduction ratio by using a work roll having a predetermined diameter in the final cold rolling Mu m, and as a result, good solder spreadability and solder adhesion were obtained.

On the other hand, in Comparative Example 1, the maximum height roughness (Rz) in the rolling parallel direction was large due to the fact that the reduction rate of the final pass was small and the solder wettability was bad. In Comparative Example 2, as the reduction rate was increased, the maximum height roughness (Rz) in the rolling parallel direction was reduced and the solder adhesion was lowered.

In Comparative Example 3, since the diameter of the work roll used in the final cold rolling was small, the maximum height roughness (Rz) in the rolling parallel direction was small and the solder adhesion was poor. In Comparative Example 4, the work roll diameter was too large, and the maximum height roughness (Rz) in the rolling parallel direction was large and the solder wettability was lowered.

In Comparative Example 5, since the Ti content was small, the maximum height roughness (Rz) in the rolling parallel direction deviated from a predetermined range, and the prototype became poor in solder wettability.

In Comparative Examples 6 and 7, since the Ti or the content of the subcomponent was large, the rolling occurred and the trial product could not be produced.

As described above, according to the present invention, it has been found that a titanium copper foil having a thickness of 0.1 占 퐉 or less can improve solder wettability and solder adhesion strength.

1 Autofocus camera module
2 York
3 lens
4 magnet
5 Carriers
6 coils
7 base
8 frames
9a upper spring member
9b lower spring member
10a, 10b cap

Claims (7)

A thickness of 0.1 mm or less, a content of Ti of 1.5 to 4.5% by mass, and the balance of copper and unavoidable impurities so that the maximum height roughness (Rz) of the surface in a direction parallel to the rolling direction is 0.1 占 퐉 to 1 Titanium copper foil. The method according to claim 1,
Titanium copper foil having a tensile strength of 1100 MPa or more. The method according to claim 1,
Wherein the total content of at least one of Ag, B, Co, Fe, Mg, Mn, Mo, Ni, P, Si, Cr and Zr is 0 to 1.0 mass%. A new copper alloy product (expanded copper product) comprising the titanium copper foil according to any one of claims 1 to 3. An electronic device part comprising the titanium copper foil according to any one of claims 1 to 3. 6. The method of claim 5,
An electronic device part in which the electronic device part is an autofocus camera module. A spring member for elastically biasing the lens at an initial position in the optical axis direction and an electromagnetic driving means for generating an electromagnetic force against the biasing 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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