JP2014019893A - Rolled copper foil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To bestow a high flex resistance and an excellent crease resistance.SOLUTION: Multiple crystal faces parallel to the principal face include a {022} face, a {002} face, a {113} face, a {111} face, and a {133} face, whereas the diffraction peak intensity ratio of the respective crystal faces calculated from X-ray diffraction measurements using a 2θ/θ method targeting the principal face and converted so as to yield a total value of 100 is I+I≥75.0, whereas on a graph plotting the average intensity of diffraction peaks of the {111} face measured by using the X-ray Pole-Figure method, the ordinate intercept [A] of a straight line linking the respective average intensities of diffraction peaks of the {111} face at tilt angles of 47° and 53° and the maximal value [B] of the average intensity of diffraction peaks of the {111} face within a tilt angle range of 15° or above and 90° or below bear a ratio of [A]/[B]<1/4.

Description

  The present invention relates to a rolled copper foil, and more particularly to a rolled copper foil used for a flexible printed wiring board.

A flexible printed circuit (FPC) is thin and excellent in flexibility, and thus has a high degree of freedom in mounting form on an electronic device or the like. For this reason, FPCs are not only for folding parts of foldable mobile phones, but also for moving parts such as digital cameras and printer heads, as well as hard disk drives (HDDs), digital versatile disks (DVDs), and compact disks (DVDs). It is often used for wiring of movable parts of disk related equipment such as CD (Compact Disk). Therefore, the rolled copper foil used as FPC and its wiring material has been required to have high bending properties, that is, excellent bending resistance that can withstand repeated bending.

  The rolled copper foil for FPC is manufactured through processes such as hot rolling and cold rolling. In the subsequent FPC manufacturing process, the rolled copper foil is bonded to an FPC base film (base material) made of a resin such as polyimide by heating or the like via an adhesive or directly. The rolled copper foil on the base material is subjected to surface processing such as etching to become a wiring. The bending resistance of the rolled copper foil is significantly improved in the state after annealing softened by recrystallization than in the hard state after cold rolling that has been rolled and hardened. Therefore, for example, in the manufacturing process of the FPC described above, the rolled copper foil is cut using the rolled copper foil after cold rolling while avoiding deformation such as elongation and wrinkles, and is superimposed on the substrate. Thereafter, the rolled copper foil and the base material are brought into close contact with each other by heating while also serving as recrystallization annealing of the rolled copper foil.

  On the premise of the above-mentioned FPC manufacturing process, various studies have been made so far on a rolled copper foil excellent in bending resistance and its manufacturing method, and the {002} plane ({200) having a cubic orientation on the surface of the rolled copper foil. } Surface) has been reported to improve the flex resistance.

For example, in Patent Document 1, annealing immediately before the final cold rolling is performed under the condition that the average grain size of the recrystallized grains is 5 μm to 20 μm. Further, the rolling degree in the final cold rolling is set to 90% or more. As a result, in a state tempered to a recrystallized structure (state after recrystallization annealing), the strength of the {200} plane obtained by X-ray diffraction of the rolled surface is I, and X-ray diffraction of fine powder copper When the intensity of the {200} plane obtained in step ₁ is I ₀ , a cubic texture with I / I ₀ > 20 is obtained.

Further, for example, in Patent Document 2, the degree of development of the cube texture before the final cold rolling is increased, and the degree of processing in the final cold rolling is set to 93% or more. Further, by performing recrystallization annealing, a rolled copper foil having a remarkably developed cubic texture with an integral strength of {200} plane of I / I ₀ ≧ 40 is obtained.

Further, for example, in Patent Document 3, the total work degree in the final cold rolling process is set to 94% or more, and the work degree per pass is controlled to 15% to 50%. Thereby, a predetermined crystal grain orientation state is obtained after recrystallization annealing. That is, the in-plane orientation degree Δβ of the {111} plane with respect to the {200} plane of the rolled plane obtained by X-ray diffraction pole figure measurement is 10 ° or less. Further, the ratio between the normalized diffraction peak intensity [a] of the {200} plane which is a cubic texture in the rolled surface and the normalized diffraction peak intensity [b] of the crystal region in the twin relation of the {200} plane. Is [a] / [b
] ≧ 3.

Moreover, for example, in Patent Document 4, the rolled copper foil before the recrystallization annealing after the final cold rolling step,
It is defined as follows. As a result obtained by X-ray diffraction 2θ / θ measurement on the rolled surface, 80% or more of the diffraction peak of the copper crystal is defined as a {220} _Cu surface ({022} surface). Also, plotting the normalized average intensity of {111} _Cu plane diffraction peaks obtained by in-plane rotation axis scanning at each tilt angle as a result obtained by measurement using the X-ray Pole-Figure method based on the rolled surface. When it does, it will be in one of the following states. In other words, the normalized average intensity in the range where the tilt angle is 35 ° to 75 ° is not stepped. Alternatively, it has a crystal grain orientation state in which only one maximum region exists. Thereby, a cubic texture is obtained after recrystallization annealing.

  In the prior art, as described above, the cube texture of the rolled copper foil is developed after the recrystallization annealing step to improve the bending resistance.

Japanese Patent No. 3009383 Japanese Patent No. 3856616 Japanese Patent No. 4285526 Japanese Patent No. 4215093

  On the other hand, in recent years, with the downsizing and thinning of electronic devices, the FPC is often folded and incorporated in a small space. In particular, in a panel portion of a smartphone or the like, an FPC in which wiring is formed may be folded at 180 ° and incorporated. For this reason, the request | requirement of the bending resistance which accept | permits a small bending radius is increasing with respect to rolled copper foil.

  In this way, depending on the application and the like, different demands may arise between bending resistance that can withstand repeated bending and bending resistance that can withstand a small bending radius. In order to meet these different requirements, conventionally, rolled copper foils having different characteristics have been separately manufactured for each application. However, such a situation is not efficient in terms of productivity, and there is a problem that profitability is poor.

  An object of the present invention is to provide a rolled copper foil that can be provided with excellent bending resistance as well as high bending resistance after the recrystallization annealing step. As described above, if a rolled copper foil having both characteristics can be realized, it can be applied to both uses that place importance on bending resistance and uses that place importance on bending resistance. Therefore, production efficiency can be remarkably improved both in the production of rolled copper foil and in the production of FPC.

According to a first aspect of the invention,
A rolled copper foil comprising a main surface, after a final cold rolling step having a plurality of crystal planes parallel to the main surface, and before a recrystallization annealing step,
The plurality of crystal planes include {022} plane, {002} plane, {113} plane, {111} plane, and {133} plane,
The diffraction peak intensity ratios of the crystal planes obtained by X-ray diffraction measurement using the 2θ / θ method with respect to the main surface and converted so that the total value becomes 100 are I _{022} and I _{002} , respectively _. , I _{113} , I _{111} , and I _{133} ,
I _{022} + I _{002} ≧ 75.0,
Using the X-ray Pole-Figure method with the main surface as a reference, the in-plane rotation angle of the main surface is 0 ° or more and 360 ° or less for each of a plurality of tilt angles within a range of 15 ° or more and 90 ° or less. Obtain the average intensity of diffraction peaks of {111} planes measured by varying within the range,
When creating a graph plotting the average intensity of diffraction peaks of the {111} plane with the tilt angle as the horizontal axis and the diffraction peak intensity as the vertical axis,
A vertical axis intercept of a straight line connecting the average intensity of the diffraction peak of the {111} plane at the tilt angle of 47 ° and the average intensity of the diffraction peak of the {111} plane at the tilt angle of 53 ° is [A When the maximum value of the average intensity of the diffraction peaks of the {111} plane in the range where the tilt angle is 15 ° or more and 90 ° or less is [B],
A rolled copper foil with [A] / [B] <1/4 is provided.

According to a second aspect of the invention,
The diffraction peak intensity ratio of the {111} plane is
The rolled copper foil as described in the 1st aspect which is I _{111} <= 10.0 is provided.

According to a third aspect of the invention,
The surface roughness of the main surface is
Ten-point average roughness Rzjis ≦ 1.5 μm,
The rolled copper foil as described in the 1st or 2nd aspect which is arithmetic mean roughness Ra <= 0.4micrometer is provided.

According to a fourth aspect of the invention,
The rolled copper foil in any one of the 1st-3rd aspect which has oxygen-free copper or tough pitch copper as a main component is provided.

According to a fifth aspect of the present invention,
The rolled copper foil in any one of the 1st-4th aspect to which at least any one of silver, boron, titanium, and tin is added is provided.

According to a sixth aspect of the present invention,
The rolled copper foil in any one of the 1st-5th aspect which is 20 micrometers or less in thickness is provided.

According to a seventh aspect of the present invention,
The rolled copper foil in any one of the 1st-6th aspect which is an object for flexible printed wiring boards is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the rolled copper foil which can be equipped with the outstanding bending resistance with high bending resistance after a recrystallization annealing process is provided.

It is a flowchart which shows the manufacturing process of the rolled copper foil which concerns on one Embodiment of this invention. It is a figure which shows the outline | summary of the measuring method of the X-ray diffraction in the Example and comparative example of this invention. It is a measurement result of X-ray diffraction using 2θ / θ method, (a) is an X-ray diffraction chart of a rolled copper foil according to Example 1 of the present invention, (b) is a rolling according to Example 2. It is an X-ray diffraction chart of copper foil, (c) is an X-ray diffraction chart of the rolled copper foil which concerns on the comparative example 1. FIG. It is the graph produced by plotting the average intensity | strength of the diffraction peak of the {111} surface which concerns on Example 1 of this invention. It is the graph produced by plotting the average intensity | strength of the diffraction peak of the {111} surface which concerns on Example 2 of this invention. It is the graph produced by plotting the average intensity | strength of the diffraction peak of the {111} surface which concerns on Example 3 of this invention. It is the graph produced by plotting the average intensity | strength of the diffraction peak of the {111} surface which concerns on Example 4 of this invention. It is the graph produced by plotting the average intensity | strength of the diffraction peak of the {111} surface which concerns on Example 5 of this invention. 6 is a graph created by plotting the average intensity of diffraction peaks on the {111} plane according to Comparative Example 1. 10 is a graph created by plotting the average intensity of diffraction peaks on the {111} plane according to Comparative Example 2. 14 is a graph created by plotting the average intensity of diffraction peaks on the {111} plane according to Comparative Example 3. 10 is a graph created by plotting the average intensity of diffraction peaks on the {111} plane according to Comparative Example 4. 10 is a graph created by plotting the average intensity of diffraction peaks on the {111} plane according to Comparative Example 5. It is a schematic diagram of the sliding bending test apparatus which measures the bending resistance of the rolled copper foil which concerns on the Example of this invention. It is a figure which shows the outline | summary of the test method of the bending resistance of the rolled copper foil which concerns on the Example of this invention. It is the graph produced by plotting the average intensity | strength of the diffraction peak of the {111} surface which concerns on Example 6 of this invention. 10 is a graph created by plotting the average intensity of diffraction peaks on the {111} plane according to Example 7. FIG. 14 is a graph created by plotting the average intensity of diffraction peaks on the {111} plane according to Comparative Example 6. It is a reverse pole figure of a pure copper type metal, and (a) is a reverse pole figure showing a crystal rotation direction by tensile deformation, and (b) is a reverse pole figure showing a crystal rotation direction by compression deformation. FIG. 6 is a diagram in which a {013} plane, a {023} plane, and a crystal plane region having a relatively small orientation difference from these crystal planes are added to a general inverted pole figure.

<Knowledge obtained by the present inventors>
As described above, in order to obtain a rolled copper foil having excellent bending resistance required for FPC applications, it is better to develop the cube orientation of the rolled surface. The present inventors have also conducted various experiments in order to increase the occupation ratio of the cube orientation. And from the experimental results so far, when the {022} plane existing after the final cold rolling step is tempered to recrystallization by the subsequent recrystallization annealing step, the {002} plane, that is, the cube orientation and It was confirmed that That is, it is preferable that the {022} plane is the main orientation after the final cold rolling step and before the recrystallization annealing step.

On the other hand, as described in the above-mentioned Patent Documents 1 to 4, and as tried by the present inventors, even if a large number of cube textures are expressed, cube aggregation in a rolled copper foil having a polycrystalline structure The {002} plane that is the organization does not occupy 100%. This is the same even before the recrystallization annealing process. In addition to the {022} plane which is the main orientation before the recrystallization annealing process and the {002} plane where the crystal orientation is maintained before and after the recrystallization, {113 }, {111} planes, {133} planes, {013} planes, {023} planes and other sub-orientation crystal planes are mixed together without being controlled. Under such a premise, as in Patent Document 4, for example, in order to control the occupation ratio of the {022} plane to 80% or more, advanced rolling technology and equipment are required.

  Moreover, it is thought that the crystal grain which has these several crystal planes has various influences on the various characteristics of a rolled copper foil. Therefore, the present inventors have focused on the sub-oriented crystal planes that have been made unnecessary so far, while maintaining high bending resistance without reducing the occupancy of the main orientation, It has been investigated whether controlling the occupancy rate can enhance other characteristics of the rolled copper foil, for example, the bending resistance, which has been increasing in demand in recent years.

  In such examination, the inventors of the present invention determined that the main surface of the rolled copper foil is a crystal plane including sub-orientations such as {113} plane, {111} plane, {133} plane, {013} plane, {023} plane, etc. The analysis of diffraction peaks at has been advanced. The diffraction peak indicates the presence of each sub-azimuth, and the occupation ratio of each sub-azimuth can be known from the intensity ratio. As a result of such diligent research, the present inventors have specified various states of diffraction peaks, and by controlling these, high bending resistance has already been obtained by controlling the {022} plane of the main orientation. It was found that the bending resistance can be further improved even under the circumstances.

  At the same time, the present inventors have further conducted intensive studies to obtain a rolled copper foil having high bending resistance required for FPC applications. As a result, it was found that not only the crystal orientation but also the unevenness of the main surface of the rolled copper foil had a great influence on the bending resistance.

  The present invention is based on these findings found by the inventors.

<One Embodiment of the Present Invention>
(1) Configuration of Rolled Copper Foil First, the configuration of the rolled copper foil according to an embodiment of the present invention, such as the crystal structure, will be described.

(Outline of rolled copper foil)
The rolled copper foil which concerns on this embodiment is comprised by the plate shape provided with the rolling surface as a main surface, for example. This rolled copper foil has a predetermined thickness by subjecting an ingot made of pure copper such as oxygen-free copper (OFC) or tough pitch copper to a hot rolling process or a cold rolling process, which will be described later. The rolled copper foil after the final cold rolling process and before the recrystallization annealing process.

  The rolled copper foil according to the present embodiment has a thickness of 20 μm by a final cold rolling process with a total workability of 90% or more, more preferably 94% or more so that it can be used for flexible wiring materials such as FPC. It is structured as follows. After that, the rolled copper foil is subjected to a recrystallization annealing process, for example, which also serves as a bonding process with a base material of FPC as described above, and has excellent bending resistance by recrystallization. Is contemplated.

  The oxygen-free copper used as a raw material is a copper material having a purity specified in JIS C1020, H3100, etc. of 99.96% or more. The oxygen content may not be completely zero, and for example, oxygen of about several ppm may be included. Further, tough pitch copper is a copper material having a purity specified in, for example, JIS C1100, H3100, etc. of 99.9% or more. In the case of tough pitch copper, the oxygen content is, for example, about 100 ppm to 600 ppm. In some cases, a small amount of a predetermined additive such as silver (Ag) is added to these copper materials to form a diluted copper alloy, and a rolled copper foil in which various properties such as heat resistance are adjusted. The rolled copper foil according to the present embodiment can contain both pure copper and dilute copper alloy, and the influence of the present embodiment on the effect of the present embodiment by the copper material and the additive material hardly occurs.

The total degree of work in the final cold rolling process is defined as T _B is the thickness of the workpiece (copper plate material) before the final cold rolling process, and T _A is the thickness of the workpiece after the final cold rolling process. Then, the total degree of processing (%) = [(T _B −T _A ) / T _B ] × 100. By setting the total workability to 90% or more, more preferably 94% or more, a rolled copper foil having excellent bending resistance can be obtained.

(Crystal structure of rolled surface)
Moreover, the rolled copper foil which concerns on this embodiment has several crystal planes parallel to a rolling surface. Specifically, after the final cold rolling step and before the recrystallization annealing step, the plurality of crystal planes include {022} plane, {002} plane, {113} plane, {111} plane, and { 133} plane is included. The {022} plane is the main orientation in the rolling plane, and the other crystal planes are sub-azimuths.

  As described above, the state of each crystal plane is controlled by a proportional relational expression that defines the state of diffraction peak intensity and the like measured for each crystal plane. The diffraction peak intensity of each crystal plane can be determined from X-ray diffraction measurement using the 2θ / θ method with respect to the rolled surface of the rolled copper foil. Here, an outline of X-ray diffraction measurement using the 2θ / θ method will be described with reference to FIG. 2 relating to an example and a comparative example described later. Details of the X-ray diffraction measurement will be described later.

  As shown in FIG. 2, a sample piece 50 such as a rolled copper foil is disposed so as to be rotatable around three scanning axes of the θ axis, the ψ axis, and the φ axis. In X-ray diffraction measurement using the 2θ / θ method, the sample piece 50 is rotated about the θ axis, and incident X-rays are incident on the sample piece 50 at an angle θ. Further, diffracted X-rays diffracted at an angle 2θ with respect to the incident direction of incident X-rays are detected. Thereby, the diffraction peak of each crystal plane parallel to the main surface of the sample piece 50 is obtained with the intensity | strength according to the occupation rate of each crystal plane in the main surface.

The diffraction peak intensity ratios I _{022} and I _{{of the} respective crystal planes are obtained by converting the diffraction peak intensities of the five crystal planes measured by X-ray diffraction into a ratio such that the total value becomes 100. _002} , I _{113} , I _{111} , and I _{133} . The diffraction peak intensity ratio is substantially equal to the occupancy ratio of each crystal plane on the rolled surface.

A conversion formula (A) for obtaining the diffraction peak intensity ratio of the {022} plane as a representative from the diffraction peak intensity of each crystal plane is shown below. Here, it is assumed that the diffraction peak intensities of the crystal planes are I ' _{022} , I' _{002} , I ' _{113} , I' _{111} , and I ' _{133} , respectively.

  In the rolled copper foil according to the present embodiment, the diffraction peak intensity ratio between the {022} plane and the {002} plane has a relationship that satisfies the following formula (1), for example.

I _{022} + I _{002} ≧ 75.0 (1)

  More preferably, in the rolled copper foil according to the present embodiment, the following expression (2) holds for the diffraction peak intensity ratio of the {111} plane.

I _{111} ≦ 10.0 (2)

  Moreover, the rolled copper foil which concerns on this embodiment has the numerical value calculated | required using the X-ray Pole-Figure (pole figure) method on the basis of the rolling surface of rolled copper foil in addition to the above-mentioned Formula (1). It is prescribed to satisfy. Here, the outline of the measurement using the X-ray Pole-Figure method will be described with reference to FIG. Details of the measurement will be described later.

  As shown in FIG. 2, in the measurement using the reflection method of the X-ray Pole-Figure method, the sample piece 50 described above is further rotated around the ψ axis, and a plurality of tilt angles within a range of 15 ° to 90 ° are obtained. Diffraction X-rays are detected for each of ψ as in the 2θ / θ method. At this time, each tilt angle ψ is measured by maintaining the angle and rotating the sample piece 50 around the φ axis to change the in-plane rotation angle φ within the range of 0 ° to 360 °. And the average intensity of diffraction peaks on the {111} plane of the obtained copper crystal is obtained.

  A method for defining the rolled copper foil according to the present embodiment using each average strength obtained by such measurement will be described below.

  With the tilt angle ψ as the horizontal axis and the diffraction peak intensity as the vertical axis, the above-mentioned {111} plane diffraction peak average intensity is plotted, for example, to create a graph as shown in FIG.

  For example, as shown in FIG. 4, the average intensity of the diffraction peak on the {111} plane when the tilt angle ψ is 47 ° and the average intensity of the diffraction peak on the {111} plane when the tilt angle ψ is 53 ° are linear. tie. Thereby, the vertical axis intercept of this straight line is obtained. At this time, the vertical axis intercept is [A].

  In addition, the maximum value of the average intensity of the diffraction peaks on the {111} plane within the graph range, that is, within the range where the tilt angle ψ is 15 ° or more and 90 ° or less is defined as [B]. At this time, in the rolled copper foil which concerns on this embodiment, the following formula | equation (3) is satisfy | filled.

      [A] / [B] <1/4 (3)

  As described above, the rolled copper foil according to the present embodiment can withstand repeated bending after the recrystallization annealing process by satisfying the conditions defined by the expressions (1) and (3), more preferably the expression (2). It is configured to have excellent bending resistance that can withstand a small bending radius in addition to high bending resistance.

(Roughness of the rolled surface)
Preferably, the rolled copper foil according to the present embodiment further has the following surface roughness in addition to the above-described configuration.

That is, the rolled copper foil according to the present embodiment is defined so that the surface roughness of the rolled surface preferably satisfies the following formulas (4) and (5) with a ten-point average roughness Rzjis and an arithmetic average roughness Ra. Has been.

Ten-point average roughness Rzjis ≦ 1.5 μm (4)
Arithmetic average roughness Ra ≦ 0.4 μm (5)

  The ten-point average roughness and the arithmetic average roughness referred to here are a ten-point average roughness Rzjis and an arithmetic average roughness Ra respectively defined by JIS B 0601: 2001. Since changes in the surface roughness symbols defined in the JIS standards are seen and easily confused, Table 1 below shows changes in the JIS standards for surface roughness.

  The ten-point average roughness Rzjis and the arithmetic average roughness Ra are obtained from a roughness curve obtained by roughness measurement.

  That is, for the ten-point average roughness Rzjis, first, a reference length is extracted from the roughness curve in the direction of the average line. A predetermined number of peaks and valleys are measured in the direction of the vertical magnification from the average line of the extracted portions. At this time, the sum of the average value of the absolute values of the altitudes of the tops from the highest peak to the fifth and the average value of the absolute values of the altitudes of the bottoms from the lowest valley to the fifth is obtained. The ten-point average roughness Rzjis represents the sum of these average values in micrometers (μm).

  For the arithmetic average roughness Ra, the absolute value of the deviation from the average line extracted from the roughness curve to the measurement curve is summed to obtain the average value. That is, the arithmetic average roughness Ra is obtained by expressing the average value obtained by dividing the area obtained by the roughness curve and the average line by the length L in micrometers (μm).

  As described above, preferably by further satisfying the formulas (4) and (5), the rolled copper foil according to the present embodiment stably exhibits excellent bending resistance as well as high bending resistance after the recrystallization annealing step. It is comprised so that it may comprise.

(2) Properties imparted to the rolled copper foil The properties to be imparted to the rolled copper foil by providing the crystal structure and surface roughness as described above will be described below.

(Regarding the crystal structure defined by the formula (1))
As described above, the {022} plane before the recrystallization annealing process changes to the {002} plane after the recrystallization annealing process, and the {002} plane before the recrystallization annealing process remains after the recrystallization annealing process. This improves the bending resistance of the rolled copper foil. That is, in the above formula (1), for example, I _{022} + I _{002} = 75.0 + 0 = 75.0 and I _{022} + I _{002} = 55.0 + 20.0 = 75.0 In some cases, it has been found that the rolled copper foil obtained after the recrystallization annealing step has substantially the same {002} plane crystal structure.

  In the recrystallization annealing process, the {002} plane does not change its crystal orientation, but becomes a seed crystal and promotes the growth of the {022} plane changing to the {002} plane. Therefore, by satisfying the above formula (1) before the recrystallization annealing step, such an effect can be sufficiently obtained.

In the rolled copper foil having a polycrystalline structure, there is a limit to improving the bending resistance by using only the {022} plane as described in Patent Document 4 described above, for example. Moreover, in order to make 80% or more of the occupation rate seen by the diffraction peak of the {022} plane in the rolled copper foil before a recrystallization annealing process, an advanced rolling technique, an installation, etc. are required.

  However, in this embodiment, not only the {022} plane but also the seed crystal is formed during the recrystallization annealing process, and the effect of the {002} plane that does not change itself after the recrystallization annealing process is also utilized. Thereby, the characteristic equivalent to or higher than the rolled copper foil of Patent Document 4 can be obtained relatively easily without excessively depending on advanced rolling technology and equipment.

That is, there are a crystal state as in Patent Document 4, that is, a state where I _{022} ≧ 80.0 and a state where I _{022} + I _{002} ≧ 75.0 as in this embodiment. It has been found that after the recrystallization annealing step, substantially the same crystal structures of {002} planes are provided. This is as if the occupancy ratio of the {002} plane after the recrystallization annealing process is more than the occupancy ratio of the {022} plane and the {002} plane before the recrystallization annealing process, for example 75.0%. For example, it appears as if it increased to 80.0% equivalent to Patent Document 4 or more. The present inventors consider that when the crystal of the {002} plane grows by recrystallization, the {002} plane takes in any other sub-azimuth including the sub-azimuth as described above, for example. This can be inferred from a phenomenon in which a large crystal grows by absorbing a small crystal as seen in, for example, Ostwald growth in the technical field of crystal growth.

  Thus, the {002} plane has a function of improving the characteristic value of the rolled copper foil even if it is in the sub-orientation.

  Note that the higher the numerical value defined by the above formula (1), the better, and so far no upper limit has been recognized. However, the numerical value serving as a standard of the formula (1) for obtaining better bending resistance can be preferably 77.5 or more, more preferably 80.0 or more.

(Regarding the crystal structure defined by the formula (2))
On the other hand, the {113} plane, {111} plane, {133} plane and other sub-directions which are sub-azimuths other than the {002} plane are unnecessary crystal planes that do not contribute to bending resistance. In addition, as a result of earnest research by the present inventors, many such sub-orientations have an adverse effect on various properties of rolled copper foil, including bending resistance and bending resistance. found.

  According to the present inventors, for example, the {111} plane has a tendency to reduce the bending resistance. In this regard, the present inventors have provided an explanation as follows.

  According to the present inventors' consideration from the viewpoint of crystal orientation, materials that are more likely to be plastically deformed when bent with a small bending radius are less prone to cracking or breaking due to bending. It tends to be excellent in bendability. Plastic deformation is caused by a phenomenon called “slip” of crystals in the material. In a copper crystal, slip occurs along the {111} plane, and the {111} plane is called a “slip plane”. However, for example, when the {111} plane of the rolled copper foil is parallel to the rolled surface, the occurrence of slippage is poor and plastic deformation is difficult to occur. Therefore, it becomes easy to generate | occur | produce a crack etc. and will become a rolled copper foil inferior to bending resistance.

Based on the above consideration, the present inventors have attempted to optimize the occupation ratio of the {111} plane. As a result, it was found that the rolled copper foil having a diffraction intensity peak ratio of the {111} plane larger than 10.0 is likely to be cracked by bending. Therefore, the {111} plane that hardly changes before and after the recrystallization annealing step preferably satisfies the above-described formula (2) in the state before the recrystallization annealing step, thereby adversely affecting the bending resistance of the {111} plane. Can be made extremely small, and the bending resistance can be further improved.

  In addition, the numerical value prescribed | regulated by above-mentioned Formula (2) is so good that it is low, and the lower limit is not recognized so far.

(Regarding the crystal structure defined by the formula (3))
The inventors of the present invention have also studied the sub-azimuths other than the {111} plane, further identified the sub-azimuths that may be disadvantageous in bending resistance, and reduced them.

  For example, the {013} plane, {023} plane, or a crystal orientation close to these crystal planes, specifically, a crystal plane having a crystal orientation within about ± 10 ° with these crystal planes is at least bent-resistant. It is considered that there is no effect of directly improving the property, and it is desirable to reduce the sub-orientation which may be disadvantageous for the bending resistance. The crystal orientation of these crystal faces does not change even after recrystallization in the recrystallization annealing process. Therefore, for these crystal faces, if the state of the rolled copper foil after the final cold rolling process and before the recrystallization annealing process can be controlled, the excellent resistance of the rolled copper foil is not hindered by the influence of these crystal orientations. Bendability can be ensured.

  By the way, the {013} plane and the {023} plane are not detected by X-ray diffraction measurement by the 2θ / θ method even if they exist on the rolled surface of the rolled copper foil. Since copper has a face-centered cubic crystal, X-ray diffraction measurement by the 2θ / θ method does not appear as a diffraction peak unless h, k, and l on the {hkl} plane are all odd or even values. This is because the diffraction peak disappears due to the extinction rule when h, k, and l are a mixture of odd and even values such as the {013} plane and the {023} plane.

  Therefore, in the present embodiment, these crystal planes are defined as in the above-described formula (3) by using the X-ray Pole-Figure method. In the above description, the diffraction peak of the {111} plane when the tilt angle ψ is 47 ° means the presence of a {013} plane parallel to the rolled surface of the rolled copper foil. Further, the state of the {013} plane can be known from the average intensity of the diffraction peaks. Further, the diffraction peak of the {111} plane at a tilt angle ψ of 53 ° means the presence of a {023} plane parallel to the rolled surface of the rolled copper foil. The state of the {023} plane can be known from the average intensity of the diffraction peaks.

  When the straight line in the graph of the average intensity of the diffraction peaks satisfies the above-described formula (3), the occupancy ratio of these crystal planes becomes a rolled copper foil, and the influence on the bending resistance can be reduced. Whether or not such a straight line satisfies the above-mentioned formula (3) is, for example, the magnitude relationship between the average intensity of the diffraction peak when the tilt angle ψ is 47 ° and the average intensity of the diffraction peak when the tilt angle ψ is 53 °, It is determined by the magnitude relationship between these average intensities and the average intensity of the maximum value of the graph, the slope of a straight line connecting two average intensities, and the like.

  The present inventors have found that the {013} plane, the {023} plane, and crystal orientations close to these crystal planes, that is, crystal planes having a relatively small difference in crystal orientation from these crystal planes are located in the rolled copper foil. When a certain amount exists, it is considered that a texture is formed. Further, the state where the vertical axis intercept [A] of the straight line obtained by the above-mentioned graph is a quarter of the maximum value [B] of the graph indicates that the boundary of whether these crystal planes form a texture or not. It is thought that it represents. That is, if [A] / [B] <1/4, the {013} plane, {023} plane, etc. do not form a texture or are insufficiently formed, and at least improve the bending resistance. It is presumed that it does not act to hinder. In addition, by forming a texture with these crystal planes [A] / [B] ≧ 1/4, the influence of these crystal orientation groups becomes so remarkable that the bending resistance is improved. It seems that there is a possibility of disturbing.

  In this regard, the present inventors believe that the action of the {002} plane after the recrystallization annealing step is involved. That is, the {002} surface seen on the rolled surface of the rolled copper foil after recrystallization annealing may contribute not only to bending resistance but also to bending resistance. Depending on whether the {013} plane or the {023} plane forms a texture, the function of the {002} plane is not fully exhibited, that is, the bending resistance is improved or deteriorated. I guess that.

  The inference that the {002} plane after the recrystallization annealing process also contributes to bending resistance is based on the following. Excellent bending resistance is required to be excellent in high cycle fatigue characteristics at low strain, and excellent bending resistance is required to be excellent in low cycle fatigue characteristics at high strain. From this, the present inventors considered that the same crystal plane, that is, the {002} plane, contributed to both the bending resistance and the bending resistance.

  Nevertheless, it is considered that the reason why both characteristics have not been completely correlated so far is based on whether the {013} plane and the {023} plane form a texture. Whether the {002} plane occupancy is sufficiently high or not, whether the bending resistance is improved depends on whether the {013} plane and the {023} plane form a texture. It is presumed that he had received.

  In the first place, the decrease in bending resistance due to the texture of these crystal planes can be explained as follows. The angle formed between the {013} plane and the {002} plane is 18.4 °, and the angle formed between the {023} plane and the {002} plane is 33.7 °. Thus, both the {013} plane and the {023} plane are greatly different in crystal orientation from the {002} plane. If the {002} plane, which is the main orientation, and the {013} plane or {023} plane having such a different crystal orientation form a texture, it is considered that the influence on bending resistance to which high strain is applied is great. Therefore, it is presumed that the bending resistance is not sufficiently exhibited due to the formation of a texture by these crystal faces.

  In addition, [A] / [B] prescribed | regulated by above-mentioned Formula (3) is so good that it is low, and the lower limit is not recognized so far.

(Surface roughness specified by Formulas (4) and (5))
As described above, the present inventors, in addition to controlling the diffraction peak intensity ratio of each crystal plane, preferably, when the surface roughness of the rolled copper foil is not more than a predetermined value, It was found that the bendability could be further improved. This is presumably because if the unevenness of the rolling surface of the rolled copper foil is large, the rolled copper foil is deformed in the direction in which the recess is opened when the rolled copper foil is bent, and cracks are likely to occur from this point.

  Initially, the present inventors decided to prescribe | regulate the surface roughness of rolled copper foil by 10-point average roughness Rzjis. By suppressing this below a predetermined value, the bending resistance of the rolled copper foil can be further improved.

  However, only by controlling the ten-point average roughness Rzjis, the bending resistance varies for each sample piece for the measurement test, and the excellent bending resistance may not be stably obtained.

  As a result of further diligent research, the present inventors have defined the surface roughness using the arithmetic average roughness Ra in addition to the ten-point average roughness Rzjis, and by controlling these, the excellent bending resistance is stable. I found out that I could get it. The present inventors have considered the following reasons in view of the characteristics of various surface roughness indices as shown in Table 1 above.

  The maximum height Rz according to JIS B 0601: 2001 shown in Table 1 above is represented by the difference between the most convex part and the most concave part. Therefore, no matter how flat the other portion is, if there is a large protruding portion or a depressed portion, the maximum height Rz becomes large.

  The ten-point average roughness Rzjis used as one of the indices of the surface roughness of the rolled copper foil according to the present embodiment is quantified by extracting the difference of five points each including the most convex part and the most concave part. It is a thing. In other words, since it is digitized using a total of 10 points of the summit and the valley bottom, not only one unevenness difference as in the above-mentioned maximum height Rz, but information on how much unevenness difference is on average can be obtained. .

  However, this alone is not sufficient to stably obtain excellent bending resistance. For example, even if the value of the ten-point average roughness Rzjis is small, there are cases where the entire measurement location has an uneven difference equivalent to the value of each of the five points of the maximum uneven portion. In this case, it means that the surface is rough as a whole. Even if there are no extremely large irregularities, if there are a large number of irregularities of a predetermined size as a whole, the probability of occurrence of cracks starting from them increases.

  On the other hand, the arithmetic average roughness Ra, which is another index of the surface roughness of the rolled copper foil, differs from the ten-point average roughness Rzjis, which focuses on the unevenness difference, how much undulation is present in the entire measurement location, Pay attention to. In other words, it is how far the roughness curve deviates from the central linear average line, and the area between the average line that is the average of the whole and the roughness of the roughness curve is seen. .

  Therefore, even if the ten-point average roughness Rzjis is within the above-described predetermined value, the arithmetic average roughness Ra may increase. In addition, when the ten-point average roughness Rzjis is extremely large, that is, when each of the five points of the maximum unevenness is extremely large, the arithmetic average roughness Ra is not present if there is no conspicuous surface roughness in other portions. May become smaller. When the unevenness is large and partial, the arithmetic average roughness Ra may be small, but the ten-point average roughness Rzjis may be large. Even if the arithmetic average roughness Ra is large, the ten-point average roughness Rzjis may not be so large.

  In view of the above, by controlling the ten-point average roughness Rzjis within a predetermined value, an extremely large unevenness difference is eliminated, and when the rolled copper foil is bent, the unevenness portion is cleaved and broken. Can be suppressed. On the other hand, by controlling the arithmetic average roughness Ra within a predetermined value, it is possible to suppress variation as a whole and to stabilize the value of the bending resistance.

  As described above, according to the present embodiment, excellent bending resistance is achieved by the internal control of the rolled copper foil that is manifested in an X-ray diffraction peak or the like such as 2θ / θ method or X-ray Pole-Figure method. And bending resistance can be imparted to the rolled copper foil. Preferably, further excellent bending resistance can be stably produced in the rolled copper foil by external control of the rolled copper foil manifested in the surface roughness of the ten-point average roughness Rzjis and the arithmetic average roughness Ra. Can be granted.

(3) Manufacturing method of rolled copper foil Next, the manufacturing method of the rolled copper foil which concerns on one Embodiment of this invention is demonstrated using FIG. FIG. 1 is a flow chart showing the manufacturing process of the rolled copper foil according to this embodiment.

(Ingot preparation step S10)
As shown in FIG. 1, first, casting is performed using pure copper such as oxygen-free copper (OFC) or tough pitch copper as a raw material to prepare an ingot. The ingot is formed in a plate shape having a predetermined thickness and a predetermined width, for example. Pure copper such as oxygen-free copper or tough pitch copper as a raw material may be a dilute copper alloy to which a predetermined additive is added in order to adjust various properties of the rolled copper foil.

  Various characteristics that can be adjusted with the additive include, for example, heat resistance. As described above, in the rolled copper foil for FPC, the recrystallization annealing step for imparting high bending resistance to the rolled copper foil is performed, for example, also as a bonding step with the FPC base material. The heating temperature at the time of bonding is set in accordance with, for example, the curing temperature of a base material made of an FPC resin or the like, the curing temperature of an adhesive to be used, and the range of temperature conditions is wide and diverse. In order to adjust the softening temperature of the rolled copper foil to the heating temperature set in this way, an additive capable of adjusting the heat resistance of the rolled copper foil may be added.

  Examples of ingots used in the present embodiment are ingots having no additive added thereto, and ingots to which several kinds of additives are added are shown in Table 2 below.

Further, as additives shown in Table 2 and other additives, for example, boron (B), niobium (Nb), titanium (Ti), nickel (about 10 ppm to 500 ppm) can be used as an additive for increasing or decreasing the heat resistance. There is an example in which one or more elements of Ni), zirconium (Zr), vanadium (V), manganese (Mn), hafnium (Hf), tantalum (Ta), and calcium (Ca) are added. Alternatively, there is an example in which Ag is added as the first additive element and any one or more of these elements listed as representative examples are added as the second additive element. In addition, chromium (Cr), zinc (Zn), gallium (Ga), germanium (Ge), arsenic (As), Cd (cadmium), indium (In), tin (Sn), antimony (Sb), gold (Au) ) Etc. can also be added in small amounts.

  Note that the composition of the ingot is maintained substantially as it is in the rolled copper foil after the final cold rolling step S40 described later, and when an additive is added to the ingot, the ingot and the rolled copper foil Have substantially the same additive concentration.

  Moreover, the temperature conditions in the below-mentioned annealing process S32 are suitably changed according to the heat resistance by a copper material or an additive. However, such a change in the temperature condition of the copper material or additive and the annealing step S32 according to the copper material or the additive hardly affects the effect of the present embodiment.

(Hot rolling process S20)
Next, the prepared ingot is hot-rolled to obtain a plate material having a thickness smaller than a predetermined thickness after casting.

(Repetition step S30)
Subsequently, a repeating step S30 is performed in which the cold rolling step S31 and the annealing step S32 are repeatedly performed a predetermined number of times. That is, work hardening is eased by subjecting a plate material cold-rolled and work hardened to an annealing treatment to anneal the plate material. By repeating this a predetermined number of times, a copper strip called “dough” is obtained. When an additive for adjusting heat resistance is added to the copper material, the temperature condition of the annealing treatment is appropriately changed according to the heat resistance of the copper material.

  In addition, in the repetition process S30, the annealing process S32 in the middle of the repetition is referred to as an “intermediate annealing process”. Further, the annealing step S32 performed at the end of the repetition, that is, immediately before the final cold rolling step S40 described later is referred to as a “final annealing step” or a “dough annealing step”. In the dough annealing step, dough annealing is performed on the copper strip (fabric) to obtain an annealed dough. Also in the dough annealing step, the temperature condition is appropriately changed according to the heat resistance of the copper material. At this time, the dough annealing step is preferably performed under a temperature condition that can sufficiently relieve the processing strain caused by each of the above-described steps, for example, a temperature condition substantially equivalent to a complete annealing treatment.

(Final cold rolling process S40)
Next, the final cold rolling step S40 is performed. The final cold rolling is also called finish cold rolling, and the cold rolling to be finished is applied to the annealed fabric a plurality of times to form a thin copper foil. At this time, the total workability is set to 90% or more, more preferably 94% or more so that a rolled copper foil having high bending resistance can be obtained. Thereby, after the recrystallization annealing process, it becomes a rolled copper foil in which more excellent bending resistance can be easily obtained.

  In addition, as described below, the degree of processing per one time (one pass) of cold rolling repeated multiple times and the movement of the position of the neutral point, preferably controlling the surface roughness of the roll used for rolling, The compressive stress and tensile stress acting on the annealed fabric during cold rolling are changed. Thereby, the diffraction peak intensity ratio of each crystal plane of the rolled copper foil can be changed.

That is, it is preferable that the degree of processing per pass is gradually reduced as the annealed dough becomes thinner each time cold rolling is repeated a plurality of times. Here, the degree of processing per pass follows the above-described example of the total degree of processing, and the thickness of the workpiece before rolling of the nth pass is T _Bn, and the thickness of the workpiece after rolling is T B _Assuming that _An is a degree of processing per pass (%) = [(T _Bn −T _An ) / T _Bn ] × 100.

  At the time of rolling, an object to be processed such as an annealed dough is reduced in thickness by, for example, being drawn into a gap between a pair of opposing rolling rolls and drawn to the opposite side. The speed of the workpiece is slower than the rotational speed of the rolling roll on the entrance side before being drawn into the rolling roll, and faster than the rotational speed of the rolling roll on the exit side after being drawn out from the rolling roll. Accordingly, the workpiece is subjected to compressive stress on the entrance side and tensile stress on the exit side. In order to thinly process a workpiece, compressive stress> tensile stress must be satisfied. By adjusting the degree of processing per pass, it is possible to adjust the ratio of each stress component (compression component and tensile component) on the premise that compression stress> tensile stress.

  In the final cold rolling step S40, it is preferable to control the position of the neutral point described below to move toward the exit side of the rolling roll every time cold rolling is repeated a plurality of times. As described above, the speed of the workpiece whose magnitude relationship is reversed between the entrance side and the exit side with respect to the rotational speed of the rolling roll is the rotational speed of the rolling roll at some position between the entrance side and the exit side. Is equal to The position where both speeds are equal is called a neutral point, and the pressure applied to the workpiece is maximized at the neutral point.

  The position of the neutral point can be controlled by adjusting a combination of front tension, rear tension, rolling speed (rolling roll rotation speed), rolling roll diameter, rolling roll surface roughness, processing degree, rolling load, and the like. it can. That is, the ratio between the compressive stress and the tensile stress can be adjusted also by controlling the position of the neutral point.

  In the final cold rolling step S40, for example, it is preferable to use a rolling roll having a surface roughness of arithmetic average roughness Ra of 0.075 μm or less. The surface roughness of the rolling roll affects the stress balance between the compression stress and the tensile stress and the surface roughness of the rolled copper foil. Therefore, the ratio of each crystal plane can be controlled by controlling the surface roughness of the rolling roll to a predetermined value. Moreover, the rolled copper foil whose surface roughness satisfy | fills said formula (4), (5) can be obtained.

  At this time, it is preferable to adjust the surface roughness of the rolling roll to a predetermined value after appropriately adjusting the oil film equivalent. The oil film equivalent is an index related to the thickness of the oil film of the rolling oil applied to the workpiece. The oil film equivalent will be described later.

  Thus, the stress balance between the compressive stress and the tensile stress at the time of the final cold rolling step S40 is controlled by the degree of processing per pass, the movement of the neutral point, the surface roughness of the rolling roll, and the like. And the balance of the diffraction peak intensity of each crystal plane is mainly determined by the stress balance between the compressive stress and the tensile stress in the final cold rolling step S40.

  Specifically, during the rolling process such as the final cold rolling step S40, the copper crystal in the copper material undergoes a rotation phenomenon due to the stress during the rolling process, and changes to the {022} plane in several paths. The greater the compressive stress, the easier it is to go through the {013} plane and {023} plane, and the greater the tensile stress, the easier it is to go through the {111} plane. And each changes to the {022} plane. A crystal that has not reached the {022} plane or a crystal that has reached the {022} plane but has been rotated to the {111} plane by the tensile stress is the sub-orientation.

Thus, by changing the stress balance between the compressive stress and the tensile stress, the path of change to the {022} plane is changed, and the balance of the diffraction peak intensities of the sub-oriented crystal planes can be adjusted. The balance of the diffraction peak intensity of the crystal plane has a great influence on the bending resistance and bending resistance of the rolled copper foil as described above.

  As described above, by performing the final cold rolling step S40 while performing the size control of the degree of processing in each pass and the position control of the neutral point, preferably the surface roughness of the rolling roll, etc. The rolled copper foil which satisfy | fills Formula (1), (3), More preferably, Formula (2) can be obtained. Preferably, the above-described surface roughness expressions (4) and (5) are predetermined values. Therefore, after the recrystallization annealing step, a rolled copper foil having high bending resistance that can withstand repeated bending and excellent bending resistance that can withstand a small bending radius can be obtained.

(Surface treatment step S50)
A predetermined surface treatment is applied to the fabric that has been formed into a copper foil through the above steps. The rolled copper foil which concerns on this embodiment is manufactured by the above.

(4) Manufacturing method of flexible printed wiring board Next, the manufacturing method of the flexible printed wiring board (FPC) using the rolled copper foil which concerns on one Embodiment of this invention is demonstrated.

(Recrystallization annealing process (CCL process))
First, the rolled copper foil according to the present embodiment is cut into a predetermined size, and bonded to an FPC base material made of a resin such as polyimide to form a CCL (Copper Clad Laminate). At this time, either a method of forming a three-layer material CCL that is bonded using an adhesive or a method of forming a two-layer material CCL that is directly bonded without using an adhesive may be used. When an adhesive is used, the adhesive is cured by heat treatment, and the rolled copper foil and the base material are brought into close contact with each other to be integrated. When an adhesive is not used, the rolled copper foil and the substrate are brought into direct contact with each other by heating and pressing. The heating temperature and time can be appropriately selected according to the curing temperature of the adhesive and the base material, and can be set to 1 to 120 minutes at a temperature of 150 to 400 ° C., for example.

  As described above, the heat resistance of the rolled copper foil is adjusted according to the heating temperature at this time. Therefore, the rolled copper foil is softened and recrystallized by heating in the CCL process. That is, the CCL process of bonding the rolled copper foil to the base material also serves as a recrystallization annealing process for the rolled copper foil. A rolled copper foil having a recrystallized structure is obtained by subjecting the rolled copper foil to a recrystallization annealing step.

  That is, most of the {022} plane that was the main orientation and the {002} plane that was the sub-azimuth before the recrystallization annealing process are {002} planes that are both tempered into a recrystallized structure. Thereby, high bending resistance is obtained.

  Further, the other sub-orientations are tempered into a recrystallized structure with almost no change while maintaining the state after the final cold rolling process even after recrystallization. However, by being in the recrystallized state, the influence of work hardening is removed from the crystal planes of these sub-orientations, and the action of the crystal planes of these sub-orientations appears in a form close to the maximum.

  For example, the action of the {013} plane and the {023} plane is exhibited, and the bending resistance is likely to be deteriorated. However, in the rolled copper foil of this embodiment, the {013} plane and the {023} plane are in a state where the occupation ratio is sufficiently low depending on the condition obtained from the above-described formula (3). Therefore, it is difficult to form a texture, and the action of the {013} plane and the {023} plane is also suppressed.

Moreover, it will be in the state which can exhibit the effect | action which reduces bending resistance by {111} surface. However, in the rolled copper foil according to the present embodiment, when the above-described formula (2) is satisfied, the occupancy of the {111} plane is in a low state, so that the action is suppressed.

  Further, when the surface roughness defined by the above-mentioned 10-point average roughness Rzjis and arithmetic average roughness Ra is a predetermined value, the variation is small, and stable and excellent bending resistance can be more easily obtained. .

  In addition, in this way, the CCL process also serves as the recrystallization annealing process, and in the process until the rolled copper foil is bonded to the base material, the rolled copper foil can be handled in a work-hardened state after the cold rolling process. It is possible to prevent deformation such as elongation, wrinkling, and bending when the rolled copper foil is bonded to the base material.

  As described above, each crystal plane in the sub-direction hardly changes before and after the recrystallization annealing process. Therefore, in order to obtain excellent bending resistance and bending resistance, the sub-orientation is controlled so that the above relational expression and conditions are satisfied for the rolled copper foil after the final cold rolling process and before the recrystallization annealing process. Just keep it.

(Surface machining process)
Next, a surface processing step is performed on the rolled copper foil bonded to the base material. In the surface processing step, for example, a wiring forming step for forming copper wiring or the like on the rolled copper foil by using a technique such as etching, and surface treatment such as plating for improving the connection reliability between the copper wiring and other electronic members. And a protective film forming step of forming a protective film such as a solder resist so as to cover a part of the copper wiring in order to protect the copper wiring and the like.

  As described above, the FPC using the rolled copper foil according to this embodiment is manufactured.

<Other Embodiments of the Present Invention>
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, It can change variously in the range which does not deviate from the summary.

  For example, in the above-described embodiment, Ag is mainly used as an additive for adjusting the heat resistance of the rolled copper foil, but the additive is not limited to those listed in Ag and the above-described representative examples. . Moreover, the various characteristics that can be adjusted by the additive are not limited to heat resistance, and the additive may be appropriately selected according to the various characteristics that require adjustment.

  In the above-described embodiment, the CCL process in the FPC manufacturing process also serves as a recrystallization annealing process for the rolled copper foil. However, the recrystallization annealing process may be performed as a separate process from the CCL process.

  Moreover, in the above-mentioned embodiment, although rolled copper foil was used for FPC use, the use of rolled copper foil is not restricted to this, It is used for the use which requires bending resistance and bending resistance. it can. The thickness of the rolled copper foil may also be ultra-thin of 10 μm or less, or over 20 μm, depending on various uses including FPC.

Further, in the above-described embodiment, the total degree of work in the final cold rolling step S40 is 90% or more and the like, and excellent bending resistance is obtained. A technique for obtaining bending resistance by adjusting the thickness can be used independently of this. That is, when the bending resistance is particularly important and it is sufficient that a certain degree of bending resistance is obtained, the total degree of work in the final cold rolling step is, for example, 85%, 75%, 65%, etc. Thus, it may be less than 90%. In addition, the technique for obtaining bending resistance by adjusting the crystal orientation of the sub-orientation and the surface roughness of the rolled copper foil can be used independently of the technique for obtaining bending resistance by adjusting the crystal face of the sub-azimuth. .

  In the above-described embodiment, in detecting the {013} plane and the {023} plane, among the X-ray pole-figure method, the measurement is performed by the reflection method, but the measurement is performed by the transmission method. It is good. In addition to the X-ray Pole-Figure method, an Inverse Pole-Figure (reverse pole figure) method and other methods may be used.

  In addition, in order to show the effect of this invention, not all the structures and processes mentioned above are necessarily essential. The various conditions given in the above-described embodiment and examples described later are merely examples, and can be changed as appropriate.

  Next, examples according to the present invention will be described together with comparative examples.

(1) Rolled copper foil using oxygen-free copper First, the rolled copper foils according to Examples 1 to 5 and Comparative Examples 1 to 5 using oxygen-free copper were manufactured as follows, and various evaluations were performed for each. . Here, first, the effects according to the above formulas (1) to (3) were verified.

(Production of rolled copper foil)
The rolled copper foil which concerns on Examples 1-5 and Comparative Examples 1-5 was manufactured by the same procedure and method as the above-mentioned embodiment using the oxygen-free copper which added Ag which makes a target density | concentration 200 ppm. However, about Comparative Examples 1-5, the processing etc. which remove | deviate a structure were included mainly in the last cold rolling process, such as the workability per pass mentioned later, and the position of a neutral point.

  Specifically, an ingot having a thickness of 150 mm and a width of 500 mm prepared by dissolving a predetermined amount of Ag in oxygen-free copper and casting was prepared. Table 3 below shows the analytical values of the Ag concentration in the ingot, which were examined by high frequency inductively coupled plasma (ICP) emission spectroscopy.

  As shown in Table 3, with respect to the target concentration of 200 ppm, the analytical values are 180 ppm to 216 ppm, both of which are suppressed to variations within about 200 ppm ± 20 ppm (10%). Ag is originally contained in oxygen-free copper, which is the main raw material, as an inevitable impurity in the range of several ppm to several tens of ppm, and due to various causes such as variations in casting an ingot, the target concentration can be reduced. Variation within ± 10% is common in the metal material field.

Next, after obtaining a plate material having a thickness of 8 mm in the hot rolling step by the same procedure and method as in the above embodiment, the cold rolling step and holding at a temperature of 750 ° C. to 850 ° C. for about 2 minutes. The intermediate annealing step was repeatedly performed to produce a copper strip (fabric) having a thickness of 0.4 mm (400 μm). continue,
An annealed dough was obtained in a dough annealing step that was held at a temperature of about 750 ° C. for about 2 minutes.

  Here, the temperature conditions of each annealing process were matched with the heat resistance of the oxygen-free copper material containing 180 ppm to 216 ppm of Ag. In addition, the reason why the different temperature conditions were used in each annealing process for copper materials with the same composition is that the heat resistance changes depending on the thickness of the copper material, and when the copper material is thin, the temperature should be lowered. Can do.

  Finally, the final cold rolling process was performed by the same procedure and method as in the above embodiment. The conditions in the final cold rolling process are shown in Table 4 below.

  As shown in Table 4, according to the progressive reduction of the plate thickness from the upper stage to the lower stage, in each of the examples and comparative examples, the conditions were changed as shown in the right column of each, and the final cold rolling was performed. . That is, the degree of processing per pass and the position of the neutral point of the cold rolling process with a thickness of 400 μm or less were changed. The position (mm) of the neutral point shown in each right column is indicated by the length from the outlet side end of the contact surface between the rolling roll and the annealed material as the workpiece to the neutral point.

  In each example and comparative example, conditions are set within the range in the right column so that each example falls within a predetermined configuration range, and each comparative example has a predetermined configuration. Processing was performed so that However, the conditions in Table 4 used this time are merely examples, and how much thickness is used to switch the conditions, and how to set the numerical values of each condition depends on the desired rolled copper foil crystal. It can select suitably according to a structure etc. As shown in the conditions of the comparative example, generally, when the thickness is sharply reduced, there is a tendency to deviate from this configuration.

  In particular, the thickness of the finally obtained rolled copper foil can be adjusted by adjusting the number of passes at the lowest stage of each condition shown in Table 4. In this example and the comparative example, the final thickness is set to 12 μm, but in order to obtain a rolled copper foil having a thickness greater than this, for example, 18 μm, the number of passes may be reduced as compared with the case of 12 μm. In addition, in order to obtain a rolled copper foil having a thickness of less than 12 μm, for example, 9 μm, the number of passes may be increased as compared with a thickness of 12 μm.

  In addition, in order to obtain excellent bending resistance, conditions were set in all of Examples 1 to 5 and Comparative Examples 1 to 5 so that the total degree of work in the final cold rolling process was 94% or more. Specifically, in all of Examples 1 to 5 and Comparative Examples 1 to 5, the total degree of processing was set to 97%. By the above, the rolled copper foil which concerns on Examples 1-5 and Comparative Examples 1-5 whose thickness is 12 micrometers was manufactured.

  The following evaluation was performed about each rolled copper foil manufactured as mentioned above.

(X-ray diffraction measurement by 2θ / θ method)
First, X-ray diffraction measurement by the 2θ / θ method was performed on the rolled copper foils according to Examples 1 to 5 and Comparative Examples 1 to 5. Details of the measurement method will be described below with reference to FIG. FIG. 2 is a diagram showing an outline of a method for measuring X-ray diffraction in Examples and Comparative Examples of the present invention.

  As shown in FIG. 2, the rolled copper foil sample pieces 50 according to Examples 1 to 5 and Comparative Examples 1 to 5 can be rotated around the three scanning axes of the θ axis, the ψ axis, and the φ axis as described above. To place. These three scanning axes are generally called a sample axis, a tilt axis, and an in-plane rotation axis, respectively. For the measurement of X-ray diffraction in the present embodiment, X-rays (Cu Kα rays) generated from a copper (Cu) tube are used.

  In the X-ray diffraction measurement using the 2θ / θ method, the sample piece 50 and a detector (not shown) are scanned (rotated around the θ axis) with respect to the incident X-ray. At this time, the scanning angle of the sample piece 50 is an angle θ, and the scanning angle of the detector is an angle 2θ. Thereby, as described above, incident X-rays are incident at an angle θ, and diffracted X-rays diffracted at an angle 2θ are detected.

  In this example and a comparative example, the measurement which concerns on the conditions shown in the following Table 5 was performed using the Rigaku Co., Ltd. X-ray-diffraction apparatus (model | form: Ultimate IV). As representatives, the X-ray diffraction charts of Examples 1 and 2 are shown in FIGS. 3A and 3B, and the X-ray diffraction chart of Comparative Example 1 is shown in FIG.

Next, the total value of diffraction peak intensities of the {022} plane, {002} plane, {113} plane, {111} plane, and {133} plane of the copper crystal measured by the 2θ / θ method is 100. In other words, the diffraction peak intensity ratio of each crystal plane was determined. Moreover, the value (I _{022} + I _{002} ) concerning Formula (1) described above was obtained. In Table 6 below, for the rolled copper foils according to Examples 1 to 5 and Comparative Examples 1 to 5, the diffraction peak intensity ratios I _{022} , I _{002} , I _{{ 113}} , I _{111} (formula (2)), the value of I _{133} , and the value of formula (1) are shown.

  As described above, in this example and the comparative example, the degree of processing per pass and the position of the neutral point in the final cold rolling process are changed. Thereby, the ratio of the stress component of the compression component added to a workpiece and a tension component changes at the time of cold rolling. As a result, the ratio of each crystal plane is changed, and the diffraction peak intensity ratio of each crystal plane shown in Table 6 and the value related to Equation (1) are also changed.

  Moreover, as shown in Table 6, in each combination of the conditions of Examples 1 to 5, each value of the formulas (1) and (2) was within the predetermined range.

  On the other hand, in the combination of the conditions of Comparative Examples 1 to 5, in some rolled copper foils, one or both of the values of the formulas (1) and (2) are outside the above predetermined range. It became. In Table 6, values outside the above-mentioned predetermined range are shown in bold with underline.

(Measurement by X-ray Pole-Figure method)
Next, the measurement by the X-ray Pole-Figure method was performed with respect to the rolled copper foil which concerns on Examples 1-5 and Comparative Examples 1-5. Such measurement methods include a reflection method in which a tilt angle ψ described later is in a range of 15 ° to 90 ° and a transmission method in which a tilt angle ψ is in a range of 0 ° to 15 °. In this example, the reflection method was used as described in the above embodiment. Details of the measurement method will be described below with reference to FIG.

  As shown in FIG. 2, in the measurement using the X-ray Pole-Figure method, the sample piece 50 of each rolled copper foil is arranged similarly to the X-ray diffraction measurement using the 2θ / θ method described above.

In the X-ray Pole-Figure method, measurement is performed using a tilt angle ψ defined as follows. That is, the tilt angle ψ in the direction perpendicular to the sample piece 50 (φ-axis direction) is set to 90.
Define as °. Further, an angle formed by the {h′k′l ′} plane, which is a crystal plane geometrically corresponding to the {hkl} plane, which is the crystal plane of interest, is defined as ψ ′. At this time, it is defined that the tilt angle ψ = 90−ψ ′.

  Under such a definition, the sample piece 50 is scanned by the ψ axis (rotated around the ψ axis), and the tilt angle ψ is changed within a range of 15 ° to 90 °. That is, the sample piece 50 is tilted at the tilt angle ψ within the above range. In this way, while changing the tilt angle ψ, diffracted X-rays are detected at a plurality of tilt angles ψ as in the 2θ / θ method. That is, when the tilt angle ψ is 90 °, the same measurement as the 2θ / θ method is performed in principle.

  In the measurement at each tilt angle ψ, the scanning angle of the detector is fixed at an angle 2θ, and the sample piece 50 is scanned on the φ axis with respect to the 2θ value on the {h′k′l ′} plane (around the φ axis). And the in-plane rotation angle φ is changed within a range of 0 ° to 360 °. That is, the sample piece 50 is rotated at an in-plane rotation angle φ within the above range. For the diffraction peaks of the {h′k′l ′} plane measured in this way, the average intensity of the diffraction peaks in the range where the in-plane rotation angle φ is 0 ° or more and 360 ° or less is obtained for each tilt angle ψ. .

  At this time, the {h′k′l ′} plane detected at a predetermined tilt angle ψ geometrically corresponds to the {hkl} plane parallel to the rolled surface of the rolled copper foil. The {hkl} planes to be noted in this embodiment are the {013} plane and the {023} plane. The {111} plane detected at a tilt angle ψ of 47 ° has a geometrical correspondence with the {013} plane parallel to the rolling plane of the rolled copper foil. Further, the {111} plane detected at a tilt angle ψ of 53 ° has a geometrical correspondence with the {023} plane parallel to the rolling plane of the rolled copper foil.

  Therefore, as described above, from the graph of the average intensity of the diffraction peak of the {111} plane obtained using the X-ray Pole-Figure method, it is determined whether or not the rolled copper foil of this example has a predetermined crystal structure. Can be determined.

  In this example and a comparative example, the above-described measurement was performed under the conditions shown in Table 7 below using an X-ray diffractometer (model: Ultimate IV) manufactured by Rigaku Corporation. 4 to 8 show graphs created by plotting the average intensity of diffraction peaks on the {111} plane according to Examples 1 to 5. FIG. Moreover, the graph created by plotting the average intensity | strength of the diffraction peak of the {111} surface which concerns on FIGS.

4 to 13, the horizontal axis is the tilt angle ψ (°), and the vertical axis is the diffraction peak intensity (
Arbitrary unit). In the graph, the average intensities obtained by the measurement using the X-ray Pole-Figure method described above are plotted. Further, the graph shows the maximum value [B] of the average intensity of diffraction peaks on the {111} plane within the range of the graph and a value of a quarter thereof. In addition, the graph shows a straight line connecting the average intensities of diffraction peaks on the {111} plane when the tilt angle ψ is 47 ° and 53 °, respectively, and its vertical axis intercept [A].

  As shown in FIGS. 4 to 13, in each of the results of Examples 1 to 5, the vertical axis intercept [A] is less than a quarter of the maximum value [B] of the graph, and the above equation (3) is obtained. I met. On the other hand, in the results of Comparative Examples 1 to 5, in all cases, the vertical axis intercept [A] was not less than ¼ of the maximum value [B] of the graph and did not satisfy the above formula (3).

(Evaluation of bending resistance)
Next, in order to examine the bending resistance of each rolled copper foil, a bending fatigue life test was performed in which the number of repeated bendings (number of bendings) until each rolled copper foil broke. Such a test was performed using an FPC high-speed bending tester (model: SEK-31B2S) manufactured by Shin-Etsu Engineering Co., Ltd. in accordance with the IPC (American Printed Circuit Industry Association) standard. FIG. 14 is a schematic diagram of a general sliding bending test apparatus 10 including an FPC high-speed bending tester manufactured by Shin-Etsu Engineering Co., Ltd.

  First, the rolled copper foil according to Examples 1 to 5 and Comparative Examples 1 to 5 was cut to a width of 12.5 mm and a length of 220 mm, and the sample piece 50 having a thickness of 12 μm was copied in accordance with the above-described recrystallization annealing step. Recrystallization annealing was performed at 300 ° C. for 60 minutes. Such a condition imitates an example of the amount of heat that the rolled copper foil actually receives in close contact with the substrate in the CCL process of the flexible printed wiring board.

  Next, as shown in FIG. 14, a sample piece 50 of rolled copper foil was fixed to the sample fixing plate 11 of the sliding bending test apparatus 10 with screws 12. Subsequently, the specimen piece 50 was attached in contact with the vibration transmission section 13, and the vibration transmission section 13 was vibrated in the vertical direction by the oscillation driver 14 to transmit vibration to the specimen piece 50, and a bending fatigue life test was performed. . As the measurement conditions for the bending fatigue life, the bending radius 10r was 1.5 mm, the stroke 10 s was 10 mm, and the amplitude number was 25 Hz. Under such conditions, five sample pieces 50 cut from each rolled copper foil were measured, and the average values of the number of bendings until breakage occurred were compared. The results are shown in Table 8 below.

  As shown in Table 8, in Examples 1 to 5 and Comparative Examples 1 and 3, both satisfy the above-described formula (1), and thus high bending resistance with a number of bendings of 2 million times or more was obtained. On the other hand, in Comparative Examples 2, 4, and 5 that do not satisfy the above-described formula (1), the number of bendings was significantly less than 2 million.

  Here, it should be noted that even Comparative Examples 2, 4, and 5 originally have a relatively high level of bending resistance. This is because, for example, the total work degree that has been obtained in the above-mentioned Patent Document 3 is 94% or more, specifically, the final cold rolling process has been performed with a total work degree of 97%. In Examples 1-5, the bending resistance can be further improved by further satisfying the above-described formula (1).

(Evaluation of bending resistance)
Subsequently, the bending resistance of each rolled copper foil was investigated. In general test standards for bending resistance, standardization for bending at 180 °, which is required for FPC applications, for example, has not been made. Then, the bending test which measures the frequency | count of bending until a crack arises in each rolled copper foil with the method shown in FIG. 15 was done.

  That is, first, a polyimide resin having a thickness of 25 μm was applied to one side of a rolled copper foil having a thickness of 12 μm according to Examples 1 to 5 and Comparative Examples 1 to 5, and then subjected to a heat treatment at 300 ° C. for 60 minutes. The resin was cured. Such heat treatment is a simulation of the CCL process and recrystallization annealing described above. Thereafter, the rolled copper foil was cut into a width of 15 mm and a length of 100 mm with respect to the rolling direction to obtain a sample piece 51 of a rolled copper foil 51 f provided with a polyimide resin layer 51 p in which a polyimide resin was cured. Next, as shown in FIG. 15, the sample piece 51 was bent 180 ° with the polyimide resin layer 51 p inside so as to sandwich the spacer 20 having a thickness of 0.4 mm. In this state, the surface of the rolled copper foil 51f at the bent portion was observed with a metal microscope to confirm the presence or absence of cracks. If there was no crack, the sample piece 51 was returned from the bent state to the original extended state. With this as one cycle, for each of the five sample pieces 51 cut out from each rolled copper foil, the cycle was repeated until cracking occurred while observing the bent portion every cycle, and the number of bending was measured. The results are shown in Table 9 below.

  As shown in Table 9, in any of Examples 1 to 5 that satisfy all of the above formulas (1) to (3), the number of bendings was 20 times or more, and excellent bending resistance was obtained.

  On the other hand, in any of the comparative examples, the expression (3) was not satisfied, and the number of bendings was less than 20. Therefore, sufficient bending resistance was not obtained. The same applies to Comparative Examples 1 to 3 that satisfy Expression (2). These bending resistances were higher than those of other comparative examples, but were inferior to those of the examples. In other words, in order to improve the bending resistance by controlling the expression (2), it is considered that the expression (3) is satisfied.

(2) Rolled copper foil using tough pitch copper Next, using a tough pitch copper to which Ag with a target concentration of 200 ppm was added, and using the same procedure and method as in the above embodiment, Example 6 having a thickness of 12 μm 7 and the rolled copper foil which concerns on the comparative example 6 were manufactured. However, about the comparative example 6, the process etc. which remove | deviated a structure, such as the conditions of the above-mentioned Table 4, were included.

  The Ag concentrations in the ingots of Examples 6 and 7 and Comparative Example 6 were 199 ppm, 193 ppm and 195 ppm as analytical values obtained by the IPC emission spectroscopic analysis method, respectively. All are variations within about ± 10% of the target concentration, and are common in the field of metal materials. In the intermediate annealing process and the dough annealing process, temperature conditions were used in accordance with the heat resistance of the tough pitch copper material containing Ag having such a concentration. Specifically, the intermediate annealing step was held at a temperature of 650 ° C. to 750 ° C. for about 2 minutes, and the dough annealing step was held at a temperature of about 700 ° C. for about 1 minute. Moreover, also about these Examples and the comparative examples, the conditions of the above-mentioned Table 4 were applied to the final cold rolling process.

  For the rolled copper foils according to Examples 6 and 7 and Comparative Example 6 manufactured as described above, the X-ray diffraction measurement by the 2θ / θ method and the X-ray Pole-Figure method were performed by the same method and procedure as the above-described example. The measurement used was performed, the above-mentioned formula (1), (2) was calculated | required, and the graph was created similarly to the above-mentioned. Table 10 below shows the results of X-ray diffraction measurement by the 2θ / θ method. In addition, FIGS. 16 to 18 show graphs according to Examples 6 and 7 and Comparative Example 6 created using the X-ray Pole-Figure method, respectively.

  Moreover, after giving the recrystallization annealing similar to the above with respect to the rolled copper foil which concerns on Example 6, 7 and the comparative example 6, a bending fatigue life test and a bending test are performed by the method and procedure similar to the above-mentioned Example. went.

  Table 11 below summarizes the above results. In Table 11, values outside the predetermined range of any of the above formulas (1) to (3) are shown in bold underlined.

  As shown in Table 11, the rolled copper foil according to any of the examples and comparative examples also satisfied the formula (1), and good bending resistance with the number of bendings of 2 million times or more was obtained. Moreover, except the comparative example 6, all the examples satisfy | filled Formula (3), and the bending resistance whose frequency | count of bending was 20 times or more was obtained. Here, the bending resistance of Comparative Example 6 that satisfies Expression (2) but does not satisfy Expression (3) is poor, and the bending resistance of Example 6 that does not satisfy Expression (2) but satisfies Expression (3) is comparative. Good. From this, it can be seen that, as described above, it is assumed that the expression (3) is satisfied in order to improve the bending resistance. If Formula (2) is further controlled after satisfying Formula (3), much more excellent bending resistance can be obtained as in Example 7.

  From the above, it can be seen that, if each condition is within a predetermined range, it is possible to obtain a good bending resistance and to further improve the bending resistance with respect to a rolled copper foil mainly made of tough pitch copper. It was.

(3) Rolled copper foil using different additives (Ag and Ti added)
Next, using oxygen-free copper to which Ag (target concentration: 120 ppm) and titanium (Ti) (target concentration: 40 ppm) are added as an additive, the thickness is 12 μm in the same procedure and manner as in the above-described embodiment. The rolled copper foil which concerns on Examples 8 and 9 and Comparative Examples 7 and 8 was manufactured. However, for Comparative Examples 7 and 8, the conditions in Table 4 described above and the like included processing that deviates from the configuration.

  Ag concentrations in the ingots of Examples 8 and 9 and Comparative Examples 7 and 8 were 110 ppm, 115 ppm, 113 ppm, and 110 ppm, respectively, as analytical values obtained by IPC emission spectroscopy. Ti concentrations were 38 ppm, 36 ppm, 37 ppm and 36 ppm, respectively. All are variations within about ± 10% of the target concentration, and are common in the field of metal materials.

  Moreover, in the intermediate annealing process and the dough annealing process, the temperature conditions according to the heat resistance of the oxygen-free copper material containing such concentrations of Ag and Ti were used. Specifically, the intermediate annealing step was held at a temperature of 650 ° C. to 750 ° C. for about 2 minutes, and the dough annealing step was held at a temperature of about 700 ° C. for about 1 minute. Moreover, also about these Examples and the comparative examples, the conditions of the above-mentioned Table 4 were applied to the final cold rolling process.

  For the rolled copper foils according to Examples 8 and 9 and Comparative Examples 7 and 8 manufactured as described above, X-ray diffraction measurement and X-ray Pole-Figure by the 2θ / θ method are performed in the same manner and procedure as in the above-described Examples. Measurement using the method was performed to obtain the above-mentioned formulas (1) to (3).

  In addition, after subjecting the rolled copper foils according to Examples 8 and 9 and Comparative Examples 7 and 8 to recrystallization annealing similar to the above, the bending fatigue life test and the bending were performed in the same manner and procedure as in the above Examples. A test was conducted.

  Table 12 below summarizes the above results. Values outside the predetermined range of any one of the above-described formulas (1) to (3) shown in Table 12 are shown in bold underlined.

  As shown in Table 12, for the rolled copper foils according to Examples 8 and 9, the relationship between the diffraction peak intensities of the crystal planes satisfied all the expressions (1) to (3). For this reason, all were able to obtain favorable bending resistance. On the other hand, with respect to the rolled copper foil according to Comparative Example 8, satisfactory bending resistance was obtained by satisfying the formula (1), but the formula (3) was out of the predetermined range, so that the formula (2) was satisfied. However, the bending resistance was poor. Moreover, about the rolled copper foil which concerns on the comparative example 7, since Formula (1) remove | deviated from predetermined value, bending resistance was bad, and although Formula (2), (3) was in the predetermined range, it was bending-proof. The result was bad. In Comparative Example 7, it is considered that the fact that the formula (1) is out of the predetermined value is a cause of deterioration of the bending resistance. That is, by satisfying the formula (1), a predetermined amount of {002} plane is contained in the rolled copper foil before the recrystallization annealing step, which improves the bending resistance by controlling the formula (3). It is considered a premise.

  From the above, it was found that if each condition is within a predetermined range, good bending resistance and bending resistance can be obtained also for the rolled copper foil added with different additives such as Ag and Ti. .

(4) Rolled copper foil using different additives (Ag and B addition (1))
Next, using oxygen-free copper to which Ag with a target concentration of 120 ppm and boron (B) with a target concentration of 100 ppm to 200 ppm added as an additive is used, the thickness is increased by the same procedure and method as in the above-described embodiment. The rolled copper foil which concerns on Examples 10 and 11 and Comparative Examples 9 and 10 of 12 micrometers was manufactured. However, for Comparative Examples 9 and 10, the processing described above in Table 4 and the like included processing that deviates from the configuration.

  The Ag concentrations in the ingots of Examples 10 and 11 and Comparative Examples 9 and 10 were 110 ppm, 120 ppm, 115 ppm, and 120 ppm, respectively, as analytical values obtained by IPC emission spectroscopy. All are variations within about ± 10% of the target concentration, and are common in the field of metal materials. The B concentrations were 115 ppm, 180 ppm, 155 ppm and 110 ppm, respectively. It is controlled within the above-mentioned range of 100 ppm to 200 ppm and is within a predetermined value. Since B is highly oxidizable and has a small atomic weight and light weight, it is oxidized during casting and separated from molten copper, and a residue (slag) called Noro floats in the molten metal. Noro floating in the molten metal becomes a loss of B, so it is general to set the concentration control range with a certain width as described above.

Moreover, in the intermediate annealing process and the dough annealing process, the temperature conditions according to the heat resistance of the oxygen-free copper material containing such concentrations of Ag and B were used. Specifically, the intermediate annealing step was held at a temperature of 630 ° C. to 780 ° C. for about 2 minutes, and the dough annealing step was held at a temperature of about 700 ° C. for about 1 minute. Moreover, also about these Examples and the comparative examples, the conditions of the above-mentioned Table 4 were applied to the final cold rolling process.

  For the rolled copper foils according to Examples 10 and 11 and Comparative Examples 9 and 10 manufactured as described above, X-ray diffraction measurement and X-ray Pole-Figure by the 2θ / θ method are performed in the same manner and procedure as in the above-described Examples. Measurement using the method was performed to obtain the above-mentioned formulas (1) to (3).

  In addition, after subjecting the rolled copper foils according to Examples 10 and 11 and Comparative Examples 9 and 10 to recrystallization annealing similar to the above, bending fatigue life test and bending are performed in the same manner and procedure as in the above Examples. A test was conducted.

  Table 13 below summarizes the above results. Values outside the predetermined range of any of the above formulas (1) to (3) shown in Table 13 are shown in bold underlined.

  As shown in Table 13, for the rolled copper foils according to Examples 10 and 11, the relationship between the diffraction peak intensities of the crystal planes satisfied all of the expressions (1) to (3). For this reason, in both cases, good bending resistance and bending resistance could be obtained. On the other hand, with respect to the rolled copper foil according to Comparative Example 9, the formulas (1) to (3) all deviated from the predetermined values, and both the bending resistance and the bending resistance were poor. Moreover, about the rolled copper foil which concerns on the comparative example 10, although favorable bending resistance was obtained by satisfy | filling Formula (1), Formula (2) and (3) remove | deviated from the predetermined range, and bending resistance is The result was bad. However, the bending resistance was slightly improved as compared with Comparative Example 9 in which the expressions (1) to (3) were all out of the predetermined values.

  From the above, it was found that, if each condition is within a predetermined range, good bending resistance and bending resistance can be obtained also for the rolled copper foil to which different additives such as Ag and B are added. .

(5) Rolled copper foil using different additives (Ag and B addition (2))
Next, in the same manner as described above, for the rolled copper foil added with Ag and B, the effects of the expressions (4) and (5) related to the surface roughness were verified in addition to the above expressions (1) to (3). .

(Production of rolled copper foil)
First, using oxygen-free copper to which Ag with a target concentration of 120 ppm and boron (B) with a target concentration of 100 ppm to 200 ppm added as an additive is used, in addition to the same procedures and methods as in the above-described embodiment, as described later. In addition, while controlling the surface roughness of the rolled copper foil, rolled copper foils according to Examples 12 to 18 and Comparative Examples 11 to 31 having a thickness of 12 μm were manufactured. However, about Comparative Examples 11-31, the process etc. which remove | deviate a structure mainly in the last cold rolling process, such as the processing degree per pass mentioned later, the position of a neutral point, and the surface roughness of a rolling roll, were included.

  Ag concentrations in the ingots of Examples 12 to 18 and Comparative Examples 11 to 31 are analytical values obtained by IPC emission spectroscopic analysis, and as shown in Table 14 below, 100 ppm to 140 ppm, all at target concentrations. On the other hand, the variation was within ± 20 ppm. Such variation is an amount that can be mixed during casting depending on casting conditions or the like when a dilute alloy is produced within a range of 100 ppm to 300 ppm, for example. That is, the total amount of the amount that can be mixed into the copper raw material to be cast and the general variation amount in casting is within the above-described range. Further, B is controlled within the range of 100 ppm to 195 ppm and the target concentration as shown in Table 15 below, and as described above, it is within a predetermined value in consideration of a loss due to Noro and the like.

  Moreover, in the intermediate annealing process and the dough annealing process, the temperature conditions according to the heat resistance of the oxygen-free copper material containing such concentrations of Ag and B were used. Specifically, in the intermediate annealing step, the temperature was maintained at 630 ° C. to 800 ° C. for about 2 minutes. The upper limit value of the temperature here was set higher because the maximum value of the Ag concentration was higher than “Ag and B addition (part 1)”. In the dough annealing process, the temperature was maintained at about 700 ° C. for about 1 minute.

  Moreover, about the present Example and the comparative example, the conditions of the following Table 16 were applied to the last cold rolling process. In applying the conditions of Table 16, the thickness of the copper strip (dough) after the repetitive process is 0.3 mm (300 μm), and the degree of processing per pass of the cold rolling process when the thickness is 300 μm or less The position of the neutral point was changed as shown in Table 16.

  Of the two conditions shown in Table 16, the conditions are adjusted so that the left side is within the range of the predetermined configuration. For all the examples and some comparative examples, conditions were set within this range, and processing was performed so that each would be within a predetermined configuration range. The right condition is a condition adjusted to deviate from the predetermined configuration. With respect to the remaining comparative examples, conditions were set within this range, and processing was performed so that each of them deviated from the predetermined configuration. The conditions in Table 16 are also exemplary as in Table 4 above.

  For example, in this example and the comparative example, the thickness of the copper strip (fabric) after the repeating process is set to 300 μm, but the thickness after the repeating process is any thickness within the range of 400 μm to 100 μm. Similarly, the same conditions as in the examples described in Table 4 or Table 16 in which the degree of processing per pass is less than 35% and the position of the neutral point is 0.4 mm or more can be used. In addition, when the repetition process is finished with a thickness exceeding 400 μm, the degree of processing per one pass and the position of the neutral point in the final cold rolling process is not limited until the thickness is reduced from the thickness to 400 μm. . In the rolling process after reaching 400 μm, the same conditions as in the examples of Table 4 or Table 16 may be used.

  In the final cold rolling step, a rolling roll having a small surface roughness with an arithmetic average roughness Ra of 0.075 μm or less is used in Examples 12 to 18 and Comparative Examples 16 to 18, 24, 26, and 29. Rolling rolls having a large surface roughness with an arithmetic average roughness Ra of 0.080 μm or more were used in the remaining Comparative Examples 11-15, 19-23, 25, 27, 28, 30, 31.

  Moreover, about the present Example and the comparative example, the total workability was set to 96% and a low setting.

  In the following Table 17, comparative examples treated under the same rolling conditions as in Examples 12 to 18 are indicated by ◯, and comparative examples treated under different rolling conditions are indicated by ×. Moreover, the comparative example processed with the rolling roll similar to Examples 12-18 is shown by (circle) and the comparative example processed with the different rolling roll by x.

(X-ray diffraction measurement)
For the rolled copper foils according to Examples 12 to 18 and Comparative Examples 11 to 31 manufactured as described above, X-ray diffraction measurement and X-ray Pole-Figure by the 2θ / θ method are performed in the same manner and procedure as in the above-described Examples. Measurement using the method was performed to obtain the above-mentioned formulas (1) to (3). The respective results are shown in Table 18 below. In Table 18, values outside the above-mentioned predetermined range are shown in bold with underline.

(Surface roughness measurement)
Then, in order to see the surface roughness of the rolled copper foil which concerns on Examples 12-18 and Comparative Examples 11-31, the 10-point average roughness Rzjis and arithmetic average roughness Ra were measured. For the measurement, a surface roughness measuring machine (model: SE500) manufactured by Kosaka Laboratory Ltd. was used. The measurement conditions were a stylus diameter of 2 μm, a measurement speed of 0.2 mm / sec, a measurement length of 4 mm, a sampling reference length of 0.8 mm, and a load of 0.75 mN or less. The measurement results are shown in Table 19 below.

  As described above, in this example and the comparative example, rolling rolls having different arithmetic average roughness Ra are used in the final cold rolling process. Therefore, as shown in Table 19, the surface of the rolled copper foil is relatively flattened with a ten-point average roughness in the combination of the conditions of the examples using the rolling rolls with a small surface roughness and some comparative examples. Both Rzjis and arithmetic average roughness Ra were within the predetermined range.

On the other hand, in the remaining comparative examples using a rolling roll having a large surface roughness, the surface roughness value of either one or both was out of the predetermined range. In Table 19, values outside the above-mentioned predetermined range are shown in bold with underline.

(Evaluation of bending resistance and bending resistance)
Next, after subjecting the rolled copper foils according to Examples 12 to 18 and Comparative Examples 11 to 31 to recrystallization annealing similar to the above, bending fatigue life tests and procedures similar to those in the above Examples were performed. A bending test was performed. The results are shown in Table 20 below.

As shown in Table 20, about the rolled copper foil which concerns on Examples 12-18, the relationship of the diffraction peak intensity | strength of each crystal plane satisfy | fills all Formula (1)-(3), and is the formula of surface roughness ( Both 4) and 5) were satisfied. For this reason, in both cases, good bending resistance and bending resistance could be obtained. In addition, even when compared with Examples 1 to 11 described above that do not consider the surface roughness of the rolled copper foil, the bending resistance is remarkably improved, and the number of bendings is 115 to 121 times. Results with little variation were obtained. On the other hand, the reason why the bending resistance is generally lower than that of the above-described Examples 1 to 11 is that the total workability in the final cold rolling step in this example is set to be low. Even under a situation where the effect of the total workability is weak, the effect of improving the bending resistance was recognized by applying the configuration of this example.

  On the other hand, for the rolled copper foils according to Comparative Examples 11 to 31, at least one of the formulas (1) to (5) or a plurality of values deviated from a predetermined value, excellent bending resistance, and stably excellent. It was not possible to combine both bending resistance. However, for Comparative Examples 11 to 14, 16 to 22, 27, and 30 that satisfy at least the formula (1), the bending resistance was as high as that of the example. Moreover, about the comparative example 29, it did not satisfy | fill only Formula (1) and the bending resistance was inferior, However, All of Formula (2)-(5) is in the predetermined range, and from other comparative examples Also resulted in excellent bending resistance. The reason why the bending resistance is inferior to that of the example is considered to be because the expression (1) is not satisfied, and it is presumed that the value of the expression (1) is also related to the bending resistance. Table 21 below summarizes all the results. In Table 21, regarding the items of the formulas (1) to (5), ◯ indicates that the value is within the predetermined value and x indicates that the value is outside the predetermined value. Moreover, regarding the item of bending resistance and bending resistance, (circle) shows good and x shows no.

  From the above, it was found that the bending resistance can be further improved by controlling the surface roughness of the rolled copper foil by using a rolling roll having a small surface roughness.

(6) Rolled copper foil using different additives (Sn addition)
Next, using oxygen-free copper to which tin (Sn) having a target concentration of 30 ppm to 100 ppm is added as an additive, Examples 19 to 25 having a thickness of 12 μm and the same procedure and method as in the above-described Examples and The rolled copper foil which concerns on Comparative Examples 32-52 was manufactured. However, about the comparative examples 32-52, the process etc. which remove | deviate from a structure, such as the conditions of above-mentioned Table 16, the surface roughness of a rolling roll, etc. were included.

The Sn concentrations in the ingots of Examples 19 to 25 and Comparative Examples 32 to 52 are analytical values obtained by IPC emission spectroscopic analysis, and are all controlled within the target concentration range as shown in Table 22 below. It had been.

  Moreover, in the intermediate annealing process and the dough annealing process, the temperature condition according to the heat resistance of the oxygen-free copper material containing such a concentration of Sn was used. Specifically, the intermediate annealing step was held at a temperature of 750 ° C. to 850 ° C. for about 2 minutes, and the dough annealing step was held at a temperature of about 800 ° C. for about 1 minute. For these examples and comparative examples, the conditions in Table 16 above were applied to the final cold rolling process.

  In the final cold rolling step, a roll having a small surface roughness with an arithmetic average roughness Ra of 0.075 μm or less is used in Examples 19 to 25 and Comparative Examples 37 to 39, 45, 47, and 50. Rolling rolls having a large surface roughness with an arithmetic average roughness Ra of 0.080 μm or more were used in the remaining Comparative Examples 32-36, 40-44, 46, 48, 49, 51, 52.

  Moreover, about the present Example and the comparative example, like the above-mentioned Examples 12-18 etc., the total processing degree was set as low as 96%.

  Table 23 below shows a comparative example treated with the same rolling conditions as in Examples 19 to 25, and a comparative example treated with different rolling conditions with x. Moreover, the comparative example processed by the rolling roll similar to Examples 19-25 is shown by (circle) and the comparative example processed by the different rolling roll is shown by x.

  With respect to the rolled copper foils according to Examples 19 to 25 and Comparative Examples 32 to 52 manufactured as described above, X-ray diffraction measurement and X-ray Pole-Figure by the 2θ / θ method are performed in the same manner and procedure as the above-described Examples. Measurement using the method was performed to obtain the above-mentioned formulas (1) to (3). Table 24 below shows the results of X-ray diffraction measurement by the 2θ / θ method. In Table 24, values outside the predetermined range of either of the formulas (1) and (2) are shown in bold underlined.

  Moreover, after performing recrystallization annealing similar to the above with respect to the rolled copper foil which concerns on Examples 19-25 and Comparative Examples 32-52, it is a bending fatigue life test and bending by the method and procedure similar to the above-mentioned Example. A test was conducted.

  Table 25 below summarizes the above results. Values outside the predetermined range of any one of the above formulas (1) to (5) shown in Table 25 are shown in bold underlined.

  As shown in Table 25, for the rolled copper foils according to Examples 19 to 25, the relationship between the diffraction peak intensities of the crystal planes satisfies all the expressions (1) to (3), and the surface roughness expression ( Both 4) and 5) were satisfied. For this reason, all were able to obtain excellent bending resistance and stable bending resistance.

On the other hand, for the rolled copper foils according to Comparative Examples 32 to 52, at least one of the formulas (1) to (5) or a plurality of values deviated from a predetermined value, excellent bending resistance, and stably excellent. It was not possible to combine both bending resistance. However, for Comparative Examples 32 to 35, 37 to 43, 48, and 51 that satisfy at least the formula (1), the bending resistance was as high as that of the example. Moreover, about the comparative example 50, only Formula (1) was not satisfy | filled but all of Formula (2)-(5) was in the predetermined range. For this reason, in addition to inferior bending resistance, bending resistance superior to those of other comparative examples and inferior to that of Examples was obtained.

  It can be seen that the results of the comparative example 29 and the comparative example 50 described above are applicable to a case where the demand for bending resistance is not so high and only the bending resistance is desired to be improved. That is, comparatively high bending resistance can be obtained by controlling only a plurality of values of formulas (2) to (5) without performing excessive control on formula (1).

  From the above, it was found that if each condition is within a predetermined range, good bending resistance and bending resistance can be obtained also for a rolled copper foil to which a different additive such as Sn is added.

<Discussion by the present inventors>
The inventors' consideration on the control of the sub-oriented crystal plane and the control of the surface roughness in the manufacturing process of the rolled copper foil described above will be described below.

(1) About crystal rotation As described above, during the rolling process such as the final cold rolling process, the copper material is subjected to compressive stress and tensile stress weaker than the compressive stress. The copper crystal in the rolled copper material causes a rotation phenomenon to the {022} plane due to the stress during the rolling process, and with the progress of the rolling process, the orientation of the crystal plane parallel to the rolled plane is mainly the {022} plane. A rolling texture is formed. At this time, as described above, the path of rotation toward the {022} plane varies depending on the ratio of the compressive stress and the tensile stress. This will be described with reference to FIG.

  FIG. 19 is a reverse pole figure of a pure copper type metal quoted from the following technical document (A), (a) is a reverse pole figure showing a crystal rotation direction by tensile deformation, and (b) is by compression deformation. It is a reverse pole figure which shows a crystal rotation direction. In the inverted pole figure, the {002} plane is expressed as {001} plane and the {022} plane is expressed as {011} plane. That is, the {002} plane is represented by the {001} plane which is the minimum value of the plane parallel to the {002} plane, and the {022} plane is the minimum value of the plane parallel to the {022} plane. Express in terms of faces.

  (B) Editor Shinichi Nagashima, “Aggregate Organization”, Maruzen Co., Ltd., January 20, 1984, p. 96, Figures 2.52 (a) and (c)

  As shown in FIG. 19, the copper crystal in the copper material rotates toward the {111} plane only by deformation due to tensile stress, and rotates toward the {011} plane only by deformation due to compressive stress. In rolling, since the compression component and the tensile component are deformed, the crystal rotation direction is not so simple. However, since the compressive component prevails over the tensile component and deforms and is rolled, the crystal rotation toward the {011} plane generally takes place, and the {111} plane changes depending on the ratio of the compressive component and the tensile component. Also try to rotate partly. At this time, since the compression component is dominant, crystal rotation is also caused in which the crystal that has been rotated to the {111} plane returns to the {011} plane. On the contrary, when a crystal rotating toward the {011} plane or a crystal reaching the {011} plane rotates toward the {133} plane or the {111} plane due to the tensile component There is also.

  Thus, when crystal rotation occurs while the compression component and the tensile component are mixed while maintaining the relationship of compression component> tensile component, the crystal plane of the main orientation finally becomes the {011} plane, As a result of crystal rotation by mixing the compression component and the tensile component, the crystal planes in the sub-orientation are considered to be {001}, {113}, {111}, and {133} planes.

  In addition, there are {013} planes, {023} planes, and the like as crystal planes that pass through crystal rotation due to compressive stress. Although the crystal orientation of the inverse pole figure shown in FIG. 20 is general, the {013} plane, the {023} plane, and a crystal plane region in which the orientation difference between these crystal planes is relatively small are drawn. added. As shown in FIG. 20, in the crystal rotation due to the compressive stress, the crystal rotates to the {011} plane ({022} plane) via the {013} plane, the {023} plane, and the like. In the rotation at the time of rolling, since there is a relationship of compressive stress> tensile stress, the {013} plane, the {023} plane, or a crystal group region composed of crystal planes having a relatively small orientation difference from these crystal planes Often passes. In the inverse pole figure of FIG. 20, the sub-orientation in the vicinity of this region can greatly affect the bending resistance. Further, during the rotation to the {022} plane, the state of crystal groups such as the {013} plane and {023} plane that have stopped rotating in this region, that is, these crystal groups form a texture. Whether or not there is a possibility of affecting the bending resistance as described above.

  In the rolling process, as described above, if both the compressive stress and the tensile stress weaker than the compressive stress are not applied to the rolled copper material, the copper material cannot be rolled while maintaining the shape of the copper material. That is, only compressive stress results in a shape that expands and spreads radially, as in mere pressing. Under the premise that compressive stress> tensile stress, the crystal that has rotated toward the {111} plane becomes the sub-azimuth due to the remaining orientation that did not reach the {022} plane and the influence of tensile stress. As described above, the {111} plane that lowers the bending resistance is a sub-orientation formed by tensile stress, and the {013} plane and the {023} plane that also lower the bending resistance are formed by compressive stress. It is a sub-azimuth.

  Therefore, in order to suppress the occupancy of the {111} plane, {013} plane, and {023} plane on the rolled surface of the rolled copper foil as much as possible, it is important to perform rolling while appropriately adjusting the balance between compression stress and tensile stress It becomes.

(2) Characteristic control in the final cold rolling process The compression component and the tensile component change the rolling conditions per pass at the time of rolling, for example, as in the final cold rolling process S40 according to the above-described embodiment. Can be controlled. That is, as tried in the above-described embodiments and examples, attention can be paid to a change in the processing degree per pass, for example.

  Moreover, in the above-mentioned embodiment and Example, the position control of the neutral point is performed together with the degree of processing per pass in the final cold rolling process. That is, in adjusting the control parameters of the compression component and the tensile component, it is possible to pay attention to, for example, a change in the position of the neutral point.

  Control factors such as the above-described degree of processing and the position of the neutral point are related to the configuration of the rolling mill and largely depend on the specifications of the rolling mill. Specifically, depending on the difference in the number of rolling rolls, the total number of rolling rolls, the combined arrangement of the rolling rolls, the diameter and material of each rolling roll, the configuration of the rolling rolls such as the surface condition (surface roughness), etc. There is a difference in the way the compressive stress is applied and the friction coefficient. If the rolling mills are different, each control factor related to the conditions mentioned in the above embodiment also has different absolute values, and can be appropriately adjusted for each rolling mill. Further, even in the same rolling mill, the absolute value of each control factor is different if the surface state of the rolling roll and the material of the rolling roll are different. Therefore, even if it is the same rolling mill, it can adjust suitably according to each state.

  In the above-described embodiments and examples, control based on the surface roughness of the rolling roll is also performed. For example, if the degree of processing per pass is constant and the surface roughness of the rolling roll is changed, the friction coefficient applied to the rolled copper material changes, the position of the neutral point changes, and the rolling load also changes. As a result, the balance between the compressive stress and the tensile stress in the rolling process changes, and the rotation direction and the rotation path of the copper crystal change.

(3) Property control by surface roughness of rolling roll As described above, the present inventors define the surface roughness of the rolled copper foil by a ten-point average roughness Rzjis and an arithmetic average roughness Ra, which are predetermined. It has been found that the bending resistance of the rolled copper foil can be improved by keeping it below the value.

Thus, the surface roughness that stably imparts excellent bending resistance to the rolled copper foil can be controlled by, for example, the following factors. That is, main factors include viscosity η of rolling oil, rotation speed U _{0 of} rolling roll, speed U ₁ of copper material during rolling, biting angle α, average rolling pressure p, surface roughness of rolling roll (arithmetic) Average roughness Ra). Among these factors, factors other than the arithmetic average roughness Ra of the rolling rolls are as oil film equivalent td corresponding to the thickness of the oil film, as in the following formula (B) with reference to the following technical literature (b). Can be combined into one.

td = {η (U ₀ + U ₁ )} / αp (B)

  (B) Akira Shodoshima, “About oil film thickness during rolling and surface roughness of rolls and materials”, Transactions of the Japan Society of Mechanical Engineers (Part 3), Vol. 44, 377, January 1978, p332-339

  If the oil film equivalent td defined by factors other than the arithmetic average roughness Ra of the rolling roll can be kept constant, the influence of these factors can be reduced, mainly by the arithmetic average roughness Ra of the rolling roll, The surface roughness of the rolled copper foil can be controlled in various ways.

Here, the rotation speed U _{0 of} the rolling roll according to the above formula (B), the speed U ₁ of the copper material during rolling, and the average rolling pressure p control the degree of processing and neutral point per pass under rolling conditions. It is also a controlling factor. In order to control the degree of processing and the neutral point per pass, when these control factors are changed, for example, the following method is used to keep the oil film equivalent td constant. For example, if it is controlled to a constant viscosity of the rolling oil η in the range of ^{3 × 10 -3 N / m 2} · s~5 × 10 -3 N / m 2 · s, the angular biting α is constant. Therefore, the oil film equivalent td can be controlled to be constant.

  In the final cold rolling step S40 according to the above-described embodiment, for example, the oil film equivalent td is appropriately adjusted, and the surface roughness of the rolling roll is set to a predetermined value, so that the rolled copper having the predetermined surface roughness is used. A foil can be produced.

  In the above-described embodiments and examples, the surface roughness of the rolling roll is defined by the arithmetic average roughness Ra for the following reason.

  That is, the rolling roll is an important tool used in the final cold rolling step S40 and related to the deformation processing of the copper material. Therefore, it is important to capture the state of the entire rolling roll as little as possible. Therefore, the arithmetic average roughness Ra captured by a surface or a line is used instead of the maximum height Rz that captures the unevenness difference at one point and the ten-point average roughness Rzjis captured at each of the five points. Thereby, the overall surface roughness of the rolling roll can be grasped.

  In addition, you may control the surface roughness of the rolled copper foil which improves bending resistance using another control factor.

(4) Other control factors In the above-described embodiments and examples, the rotation direction and the rotation path of the copper crystal were controlled by the rolling conditions including the surface roughness of the rolling roll in the final cold rolling process. Similar control is possible in other processes.

For example, by making the rolling conditions in the final cold rolling process constant and changing the manufacturing process conditions until just before the final cold rolling process, the final cold rolling process is also affected, and the rotation in the final cold rolling process It is considered possible to indirectly change the direction and the rotation path. However, if the rolling conditions in the final cold rolling process are changed as in the above-described embodiments and examples, the rotation direction and the rotation path can be directly controlled, and the controllability can be further enhanced. .

  Thus, the state of the crystal orientation of the rolled copper foil after the final cold rolling step is not limited by a specific manufacturing method. This is because the crystal orientation state of the rolled copper foil can be controlled by various methods, and there are various methods.

DESCRIPTION OF SYMBOLS 10 Sliding bending test apparatus 11 Sample fixing plate 12 Screw 13 Vibration transmission part 14 Oscillation drive body 20 Spacer 50, 51 Sample piece

Claims (7)

A rolled copper foil comprising a main surface, after a final cold rolling step having a plurality of crystal planes parallel to the main surface, and before a recrystallization annealing step,
The plurality of crystal planes include {022} plane, {002} plane, {113} plane, {111} plane, and {133} plane,
The diffraction peak intensity ratios of the crystal planes obtained by X-ray diffraction measurement using the 2θ / θ method with respect to the main surface and converted so that the total value becomes 100 are I _{022} and I _{002} , respectively _. , I _{113} , I _{111} , and I _{133} ,
I _{022} + I _{002} ≧ 75.0,
Using the X-ray Pole-Figure method with the main surface as a reference, the in-plane rotation angle of the main surface is 0 ° or more and 360 ° or less for each of a plurality of tilt angles within a range of 15 ° or more and 90 ° or less. Obtain the average intensity of diffraction peaks of {111} planes measured by varying within the range,
When creating a graph plotting the average intensity of diffraction peaks of the {111} plane with the tilt angle as the horizontal axis and the diffraction peak intensity as the vertical axis,
A vertical axis intercept of a straight line connecting the average intensity of the diffraction peak of the {111} plane at the tilt angle of 47 ° and the average intensity of the diffraction peak of the {111} plane at the tilt angle of 53 ° is [A When the maximum value of the average intensity of the diffraction peaks of the {111} plane in the range where the tilt angle is 15 ° or more and 90 ° or less is [B],
[A] / [B] <1/4, The rolled copper foil characterized by the above-mentioned. The diffraction peak intensity ratio of the {111} plane is
The rolled copper foil according to claim 1, wherein I _{111} ≦ 10.0. The surface roughness of the main surface is
Ten-point average roughness Rzjis ≦ 1.5 μm,
Arithmetic mean roughness Ra ≦ 0.4 μm, The rolled copper foil according to claim 1 or 2. The rolled copper foil according to any one of claims 1 to 3, comprising oxygen-free copper or tough pitch copper as a main component. The rolled copper foil according to any one of claims 1 to 4, wherein at least one of silver, boron, titanium, and tin is added. The rolled copper foil according to claim 1, wherein the thickness is 20 μm or less. It is an object for flexible printed wiring boards, The rolled copper foil in any one of Claims 1-6 characterized by the above-mentioned.