KR20130129054A - Rolled copper foil - Google Patents

Abstract

(task) Are equipped excellent curveproof properties and excellent bendproof properties at the same time. (solution) Multiple crystal faces in parallel with a main surface comprise {022} face, {002} face, {113} face, {111} face, and {133} face. An intensity ratio of a diffraction peak of each crystal face, which is obtained from an X-ray diffraction measurement with using a 2θ/θ method about the main surface, and also converted to make a total 100, is I {022} + I {002} ≥ 80.0, and I {111} ≤ 5.0. When a graph for depicting an average intensity of a diffraction peak of the {111} face, which is measured by using X-ray Pole-Figure method, is made, a vertical axis-intercept of a line, which connects between mutual average intensities of a diffraction peak of the {111} face at 47 degrees to 53 degrees of a tilt angle, is more than and equal to ¼ of a maximum value of an average intensity of a diffraction peak of the {111} face at 15 degrees to 90 degrees of a tilt angle. [Reference numerals] (AA) Start a process for manufacturing rolled copper foil;(BB) Repeated process;(CC) (Repetition a predetermined number of times) repeated process;(DD) End the process for manufacturing rolled copper foil;(S10) Process for preparing an ingot;(S20) Hot rolling process;(S31) Cold rolling process;(S32) Annealing process;(S40) Final cold rolling process;(S50) Surface treatment process

Description

Rolled Copper Foil {ROLLED COPPER FOIL}

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

Flexible printed wiring boards (FPCs) are thin and have excellent flexibility, and thus have a high degree of freedom in mounting form for electronic devices and the like. Therefore, the FPC is a digital versatile disk (DVD) in addition to a bent portion of a foldable cellular phone, a movable portion such as a digital camera, a print head, a hard disk drive (HDD), and the like. It is often used for wiring of moving parts of disk-related devices such as digital versatile disks (CDs) and compact disks (CDs). Therefore, rolled copper foil used as an FPC or a wiring member thereof has been required to have high bending characteristics, that is, excellent bending resistance to withstand repeated bending.

The rolled copper foil for FPC is manufactured through processes, such as hot rolling and cold rolling. The rolled copper foil is bonded by the base film (base material) of the FPC which consists of resins, such as a polyimide, or the like through the adhesive agent in the manufacturing process of the following PCC, or directly. . The rolled copper foil on a base material performs surface processing, such as etching, and becomes wiring. The flex resistance of the rolled copper foil is remarkably improved in the state after annealing softened by recrystallization than in the hard state after rolling and hardening cold rolling. Therefore, in the manufacturing process of said FPC, for example, using the rolled copper foil after cold rolling, the rolled copper foil is cut | disconnected and piled on a base material, avoiding deformation, such as elongation and a wrinkle. Thereafter, the rolled copper foil and the substrate are brought into close contact with each other to be integrated by heating as well as the recrystallization annealing degree of the rolled copper foil.

On the premise of the above manufacturing process of the FPC, various studies have been made so far on the rolled copper foil having excellent bending resistance and its manufacturing method, and the {002} plane ({200) plane which is a cubic orientation on the surface of the rolled copper foil. }, The more the flex resistance is reported as the development).

By the way, for example, in patent document 1, annealing just before final cold rolling is performed on condition that the average particle diameter of a recrystallization grain will be 5 micrometers-20 micrometers. Moreover, the rolling workability in final cold rolling shall be 90% or more. Thus, the strength of the {200} plane of the rolled surface obtained from the X-ray diffraction in the state in which the recrystallized structure is coarsened is I, and the {200} plane of the fine powder copper obtained from the X-ray diffraction When the intensity is referred to as I0, a cube aggregate having I / I0> 20 is obtained.

For example, in patent document 2, the development degree of a cube aggregate structure before final cold rolling is raised, and the workability in final cold rolling is 93% or more. Further, by performing recrystallization annealing, a rolled copper foil having remarkably developed cubic texture having an integral strength of {200} plane of I / I0? 40 is obtained.

For example, in patent document 3, the total workability in a final cold rolling process is made into 94% or more, and the workability per pass is controlled to 15%-50%. Thereby, a predetermined grain orientation state is obtained after recrystallization annealing. In other words, the in-plane orientation degree Δβ of the {111} plane with respect to the {200} plane of the rolled surface obtained by X-ray diffraction pole viscosity measurement (X 回 折 回 折 点 圖 測定) is 10 degrees or less. In addition, the ratio of the normalized diffraction peak intensity [a] of the {200} plane which is a cubic aggregate structure on the rolled surface and the normalized diffraction peak intensity [b] of the crystal region in the twin relationship between the {200} plane [a] / [b] ≥ 3.

As described above, in the prior art, by increasing the total workability of the final cold rolling process, the cube aggregate structure of the rolled copper foil is developed after the recrystallization annealing process to improve the flex resistance.

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

On the other hand, in recent years, in accordance with the miniaturization and thinning of electronic devices, the FPCs are often assembled in small spaces. In particular, in a panel portion such as a smartphone, the FPC in which the wiring is formed may be bent at 180 degrees and assembled. For this reason, the demand of the bending resistance which allows a small bending radius with respect to a rolled copper foil is increasing.

As such, depending on the use and the like, different demands may be generated such as bending resistance to withstand repeated bending and bending resistance to withstand a small bending radius. In order to cope with these different needs, conventionally, the rolled copper foil of the different characteristic was manufactured for each use. However, such a situation is not efficient in terms of productivity, and has a problem of poor profitability.

An object of the present invention is to provide a rolled copper foil which can be provided with excellent bend resistance with high bend resistance after a recrystallization annealing step. Thus, if the rolled copper foil which has both characteristics can be implement | achieved, it can apply to either the use which places importance on bending resistance, and the use which places emphasis on bending resistance. Therefore, the production efficiency can be significantly improved.

According to the first aspect of the present invention,

Rolled copper foil after the final cold rolling process and before the recrystallization annealing process, having a major surface, and having a plurality of crystal surfaces parallel to the major surface. (I)

Wherein the plurality of crystal planes include {022} plane, {002} plane, {113} plane, {111} plane and {133}

The diffraction peak intensity ratios of the respective crystal surfaces obtained from the X-ray diffraction measurement (X line) using the 2θ / θ method on the main surface and converted to a total value of 100 are each I {022). }, I {002}, I {113}, I {111} and I {133}

I {022} + I {002｝ ≥ 80.0,

I {111｝ ≤ 5.0,

For each of the plurality of tilt angles within the range of 15 degrees to 90 degrees, the in-plane rotation angle of the main surface is within the range of 0 degrees to 360 degrees using the X-ray process Obtain the average intensity of the diffraction peaks of the {111} plane

When the graph showing the average intensity of the diffraction peaks of the {111} plane was made with the tilt angle as the horizontal axis and the diffraction peak intensity as the vertical axis,

Longitudinal axis intercept that connects the average intensity of the diffraction peaks of the {111} plane at the tilt angle of 47 degrees with the average intensity of the diffraction peaks of the {111} plane at the tilt angle of 53 degrees. This rolled copper foil is provided in which the tilt angle is not less than a quarter of the maximum value of the average intensity of the diffraction peak of the {111} plane within a range of 15 degrees or more and 90 degrees or less.

According to the second aspect of the present invention,

Oxygen-free copper or tough pitch copper (TPC: Tough-Pitch Copper)

The rolled copper foil described in the first aspect is provided.

According to the third aspect of the present invention,

At least one of silver, boron, titanium and tin is added

The rolled copper foil described in the first or second aspect is provided.

According to the fourth aspect of the present invention,

The thickness is less than 20μm

The rolled copper foil in any one of 1st-3rd aspect is provided.

According to the fifth aspect of the present invention,

The total workability in the final cold rolling process is 90% or more

The rolled copper foil in any one of 1st-4th aspect is provided.

According to the sixth aspect of the present invention,

For flexible printed wiring board

The rolled copper foil in any one of 1st-5th aspect is provided.

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.

BRIEF DESCRIPTION OF THE DRAWINGS It is a flowchart which shows the manufacturing process of the rolled copper foil which concerns on one Embodiment of this invention.
Fig. 2 is a diagram showing an outline of a measuring method of X-ray diffraction in Examples and Comparative Examples of the present invention.
Fig. 3 is a measurement result of X-ray diffraction using the 2θ / θ method, (a) is an X-ray diffraction chart of a rolled copper foil according to Example 1 of the present invention, and (b) is X of a rolled copper foil according to Example 2 It is a rotational diffraction chart, (c) is an X-ray diffraction chart of the rolled copper foil which concerns on the comparative example 1.
4 is a graph showing the average intensity of the diffraction peaks of the {111} plane according to the first embodiment of the present invention.
Fig. 5 is a graph showing the average intensity of diffraction peaks on the {111} plane according to the second embodiment of the present invention.
Fig. 6 is a graph showing the average intensity of the diffraction peaks of the {111} plane according to the third embodiment of the present invention.
Fig. 7 is a graph showing the average intensity of diffraction peaks on the {111} plane according to the fourth embodiment of the present invention.
Fig. 8 is a graph showing the average intensity of the diffraction peaks on the {111} plane according to the fifth embodiment of the present invention.
9 is a graph showing the average intensity of diffraction peaks on the {111} plane in Comparative Example 1. FIG.
FIG. 10 is a graph showing the average intensity of diffraction peaks on the {111} plane in Comparative Example 2. FIG.
FIG. 11 is a graph showing the average intensity of diffraction peaks on the {111} plane in Comparative Example 3. FIG.
12 is a graph showing the average intensity of diffraction peaks on the {111} plane in Comparative Example 4. FIG.
FIG. 13 is a graph showing the average intensity of diffraction peaks on the {111} plane in Comparative Example 5. FIG.
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.
Fig. 16 is a graph showing the average intensity of diffraction peaks on the {111} plane according to the sixth embodiment of the present invention.
FIG. 17 is a graph showing the average intensity of diffraction peaks on the {111} plane in Comparative Example 6. FIG.
FIG. 18 is a graph showing the average intensity of diffraction peaks on the {111} plane in Comparative Example 7. FIG.
Fig. 19 is a reverse pole viscosity of a pure metal, in which (a) is a reverse pole figure showing a crystal rotation direction due to tensile strain, and (b) a crystal rotation direction due to compression deformation. It is the reverse pole viscosity which shows.
Fig. 20 is a diagram showing regions of crystal planes in which the orientation difference between the {013} plane, the {023} plane, and their crystal planes is relatively small in a general reverse 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 the FPC application, it is better to develop a cubic orientation of the rolled surface. The inventors also conducted various experiments to increase the occupancy of the cube orientation. From the results of the experiments thus far, the {022} surface that existed after the final cold rolling process was refined to recrystallization by a subsequent recrystallization annealing process. It confirmed that it became a {002} plane, ie, a cube orientation. In other words, it is preferable that the {022} surface is the kitchen surface after the final cold rolling process and before the recrystallization annealing process.

On the other hand, as described in Patent Documents 1 to 3 described above, and as the inventors have attempted, even if a large number of cube aggregates are expressed, the {002} plane, which is a cube aggregate structure, occupies 100% in a rolled copper foil having a polycrystalline structure. There is no case. This is the same before the recrystallization annealing process, and in the state before the recrystallization annealing process, the {113} plane, {111} plane, {133} plane, Crystal planes of negative orientations such as the {013} plane and the {023} plane are not controlled, and a plurality of them are mixed. And it is thought that the crystal grains provided with these some crystal surface have various influences on the various characteristics of a rolled copper foil. Therefore, the present inventors pay attention to the crystallographic surfaces of the negative orientations which have been considered unnecessary so far, and the bending resistance of the rolled copper foil is determined by the crystallographic surfaces of these negative orientations while maintaining high bend resistance without reducing the occupancy of the kitchen. It has been examined whether it cannot be increased.

In this study, the present inventors and the like diffraction in the main surface of the rolled copper foil of each crystal plane including suborientations such as {113} plane, {111} plane, {133} plane, {013} plane, and {023} plane. The interpretation of the peak was advanced. The diffraction peak indicates the presence of each sub-direction, and the occupancy ratio of each sub-direction can be known from the intensity ratio. As a result of diligent research, the present inventors have found that there are things that reduce and improve the bending resistance of the rolled copper foil among the crystal faces of these sub-orientations. Therefore, if the occupancy ratio of these negative orientations can be controlled based on the information obtained from the diffraction peaks on the main surface of the rolled copper foil, it is possible to equip the rolled copper foil after the recrystallization annealing process with high bending resistance. . The present inventors have variously defined the states of such diffraction peaks, and have also found a method of controlling them. Accordingly, high bending resistance can be obtained by controlling the {022} surface of the kitchen table, and further, bending resistance can be improved.

This invention is based on this knowledge which the inventors etc. found.

<1 embodiment of this invention>

(1) Composition of rolled copper foil

First, the structure of the crystal structure of the rolled copper foil which concerns on one Embodiment of this invention, etc. is demonstrated.

(Outline of rolled copper foil)

The rolled copper foil which concerns on this embodiment is comprised by the plate shape which has a rolling surface as a main surface, for example. This rolled copper foil is mentioned later on the ingot which uses pure copper, such as oxygen-free copper (OFC: Oxygen-Free Copper) and tough pitch copper (TPC: Tough-Pitch Copper) as a raw material, for example. It is a rolled copper foil after the final cold rolling process which carried out a hot rolling process, a cold rolling process, etc. to predetermined thickness, and before a recrystallization annealing process.

The rolled copper foil which concerns on this embodiment is comprised so that it may be used for the flexible wiring material use of a FPC, for example. That is, the final cold rolling process having a total workability of 90% or more, more preferably 94% or more, has a thickness of 20 μm or less. As mentioned above, such a rolled copper foil serves also as the process of joining of the base material of a FPC, for example, and the recrystallization annealing process is performed and recrystallization is aimed at providing excellent bending resistance.

Oxygen-free copper which becomes a raw material is a copper material whose purity prescribed | regulated to JIS C1020, H3100, etc. is 99.96% or more, for example. Oxygen content may not be zero completely, For example, oxygen may be contained about several km. In addition, tough pitch copper is a copper material of 99.9% or more of purity prescribed | regulated to JIS C1100, H3100, etc., for example. In the case of tough pitch copper, oxygen content is about 100 mm-about 600 mm, for example. A small amount of a predetermined additive such as silver (Ag) is added to these copper materials to form a lean copper alloy, and a rolled copper foil in which various characteristics such as heat resistance are adjusted may be used. The rolled copper foil which concerns on this embodiment can contain both pure copper and a lean copper alloy, and hardly the influence on the effect of this embodiment by the copper material or an additive material of a raw material hardly arises.

The total workability in the final cold rolling process is Tb as the thickness of the object to be processed (the sheet of copper) before the final cold rolling process, and the thickness of the object after the final cold rolling process as Ta is the total workability (%). = [(TV-TA) / TV] X 100 is represented. By making the total workability 90% or more, more preferably 94% or more, a rolled copper foil excellent in flex resistance is obtained.

(Crystal Structure of Rolled Surface)

Moreover, the rolled copper foil which concerns on this embodiment is equipped with the some crystal surface parallel to a rolling surface. Specifically, in the state after the final cold rolling process and before the recrystallization annealing process, the plurality of crystal planes include {022} planes, {002} planes, {113} planes, {111} planes and {133} planes. The {022} surface is a kitchen surface in a rolled surface, and each crystal surface other than that is negative orientation.

As described above, the state of each of the crystal planes is controlled by a proportional relation that variously defines the states such as the diffraction peak intensity measured for each crystal plane. The diffraction peak intensity of each crystal surface can be calculated | required from the X-ray diffraction measurement using the 2 (theta) / (theta) method with respect to the rolling surface of a rolled copper foil. Here, the X-ray diffraction measurement using the 2θ / θ method will be described with reference to FIG. 2 regarding Examples and Comparative Examples described later. In addition, the description here is only schematic and detailed later.

As shown in FIG. 2, sample pieces 50, such as a rolled copper foil, are rotatably arrange | positioned centering around three scanning axes of a (theta) axis | shaft, a (phi) axis, and a (phi) axis. In the 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, the diffraction X-ray bent at an angle (2θ) with respect to the incident direction of the incident X-rays is 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 occupancy rate of each crystal surface in the main surface.

The diffraction peak intensities of the five crystal planes measured by the X-ray diffraction are converted into ratios in which the total value is 100, which is the diffraction peak intensity ratio of each crystal plane. This diffraction peak intensity ratio is approximately equal to the occupancy of each crystal surface in the rolled surface.

The conversion formula (A) which calculates the diffraction peak intensity ratio of the {022} plane as a representative from the diffraction peak intensity of each crystal surface is shown below. Here, the diffraction peak intensity ratios of each crystal plane are referred to as I {022}, I {002}, I {113}, I {111}, and I {133}, respectively, and the diffraction peak strengths of each crystal plane are respectively I 'I022}. , I '# 002}, I' # 113}, I '# 111} and I' # 133}.

[Number 1]

In the rolled copper foil which concerns on this embodiment, the diffraction peak intensity ratio of a {022} surface and a {002} surface has a relationship which the following formula | equation (1) holds, for example.

I {022} + I {002｝ ≥ 80.0... (One)

In addition, in the rolled copper foil which concerns on this embodiment, the following formula | equation (2) is established about the diffraction peak intensity ratio of a {111} plane.

I {111｝ ≤ 5.0... (2)

Moreover, in addition to said Formula (1), (2), the rolled copper foil which concerns on this embodiment is prescribed | regulated so that the numerical value calculated | required using the X-ray-film FIGEL method (pole viscosity) method may also be satisfied. Here, the measurement using the X-ray photoresist method will be described with reference to FIG. 2. In addition, the description here is only schematic and detailed later.

As shown in Fig. 2, in the measurement using the X-ray method, the sample piece 50 is further rotated around the ψ axis, and a plurality of tilt angles (ψ) within a range of 15 degrees or more and 90 degrees or less. For each of), diffraction X-rays are detected in the same manner as in the 2θ / θ method. At this time, in each tilt angle ψ, while maintaining the angle, the sample piece 50 is rotated about the φ axis, and the in-plane rotation angle φ is within the range of 0 degrees or more and 360 degrees or less. The measurement was carried out by changing the average strength of the diffraction peaks of the {111} plane of the obtained copper crystal.

The method of defining the rolled copper foil which concerns on this embodiment using each average strength calculated | required by such a measurement is demonstrated below.

With the tilt angle ψ as the horizontal axis and the diffraction peak intensity as the vertical axis, the average intensity of the diffraction peaks of the {111} plane is shown, for example, a graph as in FIG. do.

For example, as shown in Fig. 4, the average intensity of the diffraction peak of the {111} plane at tilt angle 47 and the tilt angle of the diffraction peak of {111} plane at 53 degrees Connect average strength in a straight line. Thereby, the longitudinal axis intercept of this straight line is obtained.

In the rolled copper foil according to the present embodiment, the average longitudinal strength of the diffraction peak of the {111} plane within the range of the graph, that is, within the range of 15 degrees to 90 degrees, in the range of the graph. Is more than a quarter of the maximum.

As described above, by satisfying the conditions defined by the formulas (1) and (2) and the graph of the average strength of the diffraction peaks, the rolled copper foil according to the present embodiment is repeatedly subjected to a recrystallization annealing process as described below. It is configured to have a high bending resistance with bending and excellent bending resistance withstanding a small bending radius.

(Characteristics given to rolled copper foil)

The characteristic of what is provided to a rolled copper foil is demonstrated below by providing the crystal structure as mentioned above.

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 as it is after the recrystallization annealing process, thereby improving the flex resistance of the rolled copper foil. . In the recrystallization annealing step, the {002} plane becomes seed crystal although its crystal orientation does not change, and the {022} plane is changed to the {002} plane to promote growth. Therefore, such an effect can be sufficiently obtained by satisfying the above formula (1) before the recrystallization annealing step.

However, the {002} plane does not need to exist here. That is, the diffraction peak intensity ratio I {002} of the {002} plane may be zero. In the above formula (1), for example, in the case of I {022} + I {002} = 80.0 + 0 = 80.0, and in the case of I {022} + I {002} = 60.0 + 20.0 = 80.0, It can be seen that the rolled copper foil obtained after the recrystallization annealing process has crystal structures of substantially the same {002} plane. In addition, the higher the numerical value defined by the left side of the above formula (1), the better, and there has been no harm due to the excessively high value of I {022} + I {002}.

On the other hand, the {113} planes, {111} planes, and {133} planes of other orientations are unnecessary crystal planes which do not contribute to flex resistance. In particular, as a result of intensive studies by the inventors, it has been found that the {111} plane has a tendency to lower the bending resistance. Accordingly, by satisfying the above formula (2), the adverse effect on the bending resistance due to the {111} plane can be extremely small. The lower the left side of the above formula (2), that is, the lower the numerical value defined by I {111 ', the better. The higher the value of I {111' is, the better.

In addition, the present inventors have continued to study other orientations other than the above-described crystal planes, and have come to specify the minor orientations that are advantageous in bending resistance. That is, for example, a {013} plane or a {023} plane, or a crystal orientation close to the crystal plane thereof, specifically, a crystal plane having a crystal orientation within ± 10 degrees of these crystal planes has an effect of improving bending resistance. Equipped. In addition, the crystal orientation of these crystal planes does not change even after recrystallization in the recrystallization annealing step. Therefore, also regarding these crystal surfaces, if the state in the rolled copper foil after the final cold rolling process and before the recrystallization annealing process can be controlled, excellent bending resistance can be provided to the rolled copper foil.

By the way, even if the {013} plane and the {023} plane existed in the rolled surface of the rolled copper foil, for example, it is not detected by X-ray diffraction measurement by a 2 (theta) / (theta) method. Since copper is a crystal of the surface-centered cubic structure, X-ray diffraction measurement by the 2θ / θ method does not appear as diffraction peaks unless the ｈ, k, and l on the {ｈｋｌ} plane are all odd or even. This is because the diffraction peaks are lost by the extinction rule when h, k, and l have an odd value and an even value, such as the {013} plane or the {023} plane.

Here, in this embodiment, these crystal planes are prescribed | regulated using the X-ray-Firegraph method. In the above description, the diffraction peak of the {111} plane at the tilt angle ψ of 47 degrees means the presence of the {013} plane parallel to the rolled surface of the rolled copper foil. In addition, the state of the {013} plane can be known from the average intensity of the diffraction peaks. In addition, the diffraction peak of {111} plane whose tilt angle (psi) is 53 degree | times means the presence of the {023} plane parallel to the rolling surface of a 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 peak satisfies the conditions as described above, the occupancy ratio of these crystal surfaces becomes sufficiently high that the rolled copper foil can be provided with excellent bending resistance. Whether or not such a straight line satisfies these conditions is, for example, the relationship between the average intensity of the diffraction peak at tilt angle 47 and the average intensity of the diffraction peak at tilt angle 53 °. And the magnitude of the average intensity of the graph and the average intensity of the maximum value of the graph, the slope of a straight line connecting two average intensities, and the like.

Furthermore, the present inventors have considered as follows that the bending resistance is imparted to the rolled copper foil by satisfying the above conditions using a graph of the average strength of the diffraction peaks. The {013} plane or {023} plane and the crystal orientations close to these crystal planes, that is, the crystal planes with relatively small crystal orientation differences between them, can be considered to form an aggregate structure when a predetermined amount exists in the rolled copper foil. Moreover, it is thought that these crystal planes contribute to the improvement of bending resistance by forming an aggregate structure. The inventors think that the vertical axis intercept of the straight line obtained by the above graph being one quarter with respect to the maximum value of the graph indicates the boundary of whether or not these crystal planes form an aggregate structure.

(2) 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. 1 is a flowchart showing the manufacturing process of the rolled copper foil according to the embodiment.

(Preparation process of ingot (S10))

As shown in FIG. 1, first, an ingot (ingot) is prepared by casting using pure copper such as oxygen-free copper (OCF) or tough pitch copper as a raw material. 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 and tough pitch copper, which are used as raw materials, may be a lean copper alloy to which a predetermined additive is added in order to adjust various characteristics of the rolled copper foil.

Various characteristics which can be adjusted with an additive material have heat resistance, for example. As described above, in the rolled copper foil for FPC, the recrystallization annealing step for obtaining high refractive resistance is also performed, for example, as a step of joining the substrate of the FPC. The heating temperature at the time of joining is set together with the hardening temperature of the base material which consists of resin of FPC etc., the hardening temperature of the adhesive agent used, etc., and the range of temperature conditions varies widely. In order to match the softening temperature of the rolled copper foil with the heating temperature set in this way, the additive which can adjust the heat resistance of a rolled copper foil may be added.

As an ingot used for this embodiment, the ingot which did not add an additive material, and the ingot which added some kind of additive material are illustrated in the following Table 1.

Table 1

Here, the additives shown in Table 1 and other additives include boron (B), niobium (Ni), titanium (Ti), and nickel (Ni) of about 10 mM to 500 mM, for example, an additive which raises or lowers the heat resistance. ), Zirconium (Vr), vanadium (V), manganese (Mn), hafnium (Hv), tantalum (Ta) and calcium (Ca). Alternatively, there is an example in which Ag is added as the first additive element, and any one or a plurality of elements of these elements which are typical examples of the second additive element are added. In addition, chromium (Cr), zinc (Ga), gallium (Ga), germanium (arsen), arsenic (AS), Cd (cadmium), indium (IN), tin (Sn), antimony (SV), gold ( A small amount of Au may be added.

In addition, the composition of the ingot is substantially maintained even in the rolled copper foil after passing through the final cold rolling step (S40) described later, and when the additive is added to the ingot, the ingot and the rolled copper foil have approximately the same additive concentration.

In addition, the temperature conditions in the annealing process S32 mentioned later change suitably according to the heat resistance by a copper material or an additive material. However, such a copper material, an additive material, and thus a change in the temperature condition of the annealing step S32 have little influence on the effect of the present embodiment.

(Hot rolling step (S20))

Next, the prepared ingot is hot rolled to obtain a plate material having a thickness thinner than a predetermined thickness after casting.

(Repeating step (S30))

Subsequently, repeating step S30 of repeatedly performing the cold rolling step S31 and the annealing step S32 for a predetermined number of times is performed. In other words, the work hardening is alleviated by performing annealing on the plate hardened by cold rolling and annealing the plate. By repeating this a predetermined number of times, copper (tuned) called "dough" is obtained. When an additive material for adjusting the heat resistance is added to the copper material, the temperature conditions of the annealing treatment are appropriately changed in accordance with the heat resistance of the copper material.

In addition, in the repetition process S30, the annealing process S32 in the middle of a repetition is called "intermediate annealing process." In addition, the annealing process S32 which is performed immediately after the end of repetition, ie, the final cold rolling process S40 mentioned later, is called a "final annealing process" or a "dough annealing process." In the dough annealing step, the dough (annealed) is subjected to dough annealing to obtain an annealed dough. Also in a dough annealing process, temperature conditions are changed suitably according to the heat resistance of a copper material. At this time, the dough annealing step is preferably carried out under a temperature condition that can sufficiently alleviate the processing distortion caused by each of the above steps, for example, a temperature condition approximately equal to that of the complete annealing treatment.

(Final cold rolling process (S40))

Next, the final cold rolling step (S40) is performed. Final cold rolling is also called finish cold rolling, and cold rolling which is finished is applied to the annealed sheet several times. At this time, the total workability is 90% or more, more preferably 94% or more so as to obtain a rolled copper foil having high flex resistance. Thereby, after a recrystallization annealing process, it becomes a rolled copper foil which is easy to acquire the more excellent bending resistance characteristic.

Further, as the annealed dough becomes thinner every time the cold rolling is repeated several times, it is preferable to gradually reduce the workability per one pass (one pass). Here, according to the example of the above-mentioned total workability, when the thickness of the object to be processed before the n-th pass rolling is Tn, and the thickness of the object to be processed after rolling is TAN, the degree of work per one pass ( %] = [(ＴＢｎ-ＴＡｎ) / ＴＢｎ] It is represented by X100.

Thus, the diffraction peak intensity ratio of each crystal surface of a rolled copper foil can be controlled by changing the workability per pass.

At the time of rolling processing, objects to be processed, such as annealing dough, are pulled in the clearance gap between the rolls which oppose each other, for example, and are pulled out to the opposite side, and thickness reduces. The speed of the object to be processed is slower than the rotational speed of the roll on the inlet side before being drawn into the roll, and faster than the rotational speed of the roll on the outlet side after being drawn out from the roll. Therefore, the compressive stress is applied to the object to be processed on the inlet side and the tensile stress on the outlet side. In order to process the object to be processed thinly, compressive stress> tensile stress must be used. By adjusting the degree of work per pass, the ratio of each stress component (compression component and tensile component) can be adjusted assuming that compressive stress> tensile stress.

In the final cold rolling step S40, the adjustment of the ratio of the stress component (compression component and tensile component) can also be made from the viewpoint of controlling the positional shift of the neutral point described below. That is, as mentioned above, the speed of the object to be processed whose size is reversed on the inlet side and the outlet side with respect to the rotational speed of the roll is equal to the rotational speed of the roll at a position somewhere between the inlet side and the outlet side. The position where these velocities are the same is called a neutral point, and the pressure exerted on the workpiece is maximum at the neutral point.

The position of the neutral point is the front tension, the rear tension, the rolling speed (rolling speed), the roll diameter, the surface roughness of the roll, the workability, the rolling load. It can control by adjusting a combination of (weight) etc. That is, the ratio of the compressive stress and the tensile stress can be adjusted by controlling the position of the neutral point.

The balance of the diffraction peak intensities of each crystal plane is mainly determined by the stress balance between the compressive stress and the tensile stress in the final cold rolling process.

Specifically, at the time of rolling processing such as the final cold rolling step (S40), the copper crystal in the copper material causes rotational phenomenon due to the stress at the time of rolling, and changes to the {022} plane in several paths. The greater the compressive stress, the easier it is to pass through the {013} plane or the {023} plane, and the greater the tensile stress, the easier to pass the {111} plane. And each changes to the {022} plane. Crystals which do not reach the {022} plane or crystals which have reached the {022} plane but have rotated to the {111} plane due to tensile stress become negative orientations.

By changing the stress balance between the compressive stress and the tensile stress in this manner, it is possible to adjust the balance of the diffraction peak strength of the crystal plane in the negative orientation. As described above, the balance of the diffraction peak strength of the crystal plane greatly affects the bending resistance and the bending resistance of the rolled copper foil.

The rolled copper foil which satisfies said Formula (1) and (2) can be obtained by performing final cold rolling process S40, carrying out size control of the workability in each path, control of the position of a neutral point, etc. Further, the longitudinal axis intercept of the graph of the average intensity of the diffraction peaks on the {111} plane is equal to or more than one fourth of the maximum value of the graph. Therefore, after the recrystallization annealing process, a rolled copper foil having high bending resistance withstanding repeated bending and excellent bending resistance withstanding a small bending radius is obtained.

(Surface Treatment Step (S50))

The predetermined surface treatment is given to copper which passed through the above process. The rolled copper foil which concerns on this embodiment is manufactured by the above.

(3) 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 step (CCL step))

First, the rolled copper foil which concerns on this embodiment is cut | disconnected to predetermined | prescribed size, and it joins with the base material of FPC which consists of resins, such as polyimide, for example, and forms a copper clad laminate. At this time, you may use either the method of forming the three-layer material CCL which bonds through an adhesive agent, and the method of forming the two-layer material CCL which directly bonds without an adhesive agent. When using an adhesive agent, an adhesive agent is hardened by heat processing, a rolled copper foil and a base material adhere | attach, and are integrated. When not using an adhesive agent, a rolled copper foil and a base material directly adhere | attach by heating and pressure. Heating temperature and time can be suitably selected according to the curing temperature of an adhesive agent and a base material, etc., For example, it can be made into 1 minute or more and 120 minutes or less at the temperature of 150 degreeC or more and 300 degrees C or less.

As mentioned above, the heat resistance of the rolled copper foil is adjusted to the heating temperature at this time. Therefore, the rolled copper foil softens and recrystallizes by heating in a CCL process. That is, the CCL process which joins a rolled copper foil to a base material also serves as the recrystallization annealing process with respect to a rolled copper foil. The recrystallization annealing process is performed with respect to the rolled copper foil, and the rolled copper foil which has a recrystallization structure is obtained.

That is, before the recrystallization annealing process, most of the {022} plane which was the kitchen surface and the {002} plane which was the sub-orientation were the {002} plane formed together with the recrystallization structure. As a result, high bending resistance is obtained.

In addition, other negative orientations hardly change even after recrystallization, and are refined into a recrystallized structure. However, by the recrystallization state, the influence of work hardening on the crystal faces of these sub-orientations is removed, and the action of the crystal surfaces of these sub-orientations is expressed in a form close to the maximum.

For example, the action of lowering the bend resistance is exerted by the {111} plane. However, the rolled copper foil which concerns on this embodiment satisfy | fills said Formula (2), and the action is suppressed in the state where the occupancy rate of a {111} surface is low. Moreover, the effect | action which improves the bending resistance which a {013} plane or a {023} plane has is exhibited. At this time, the {013} plane and the {023} plane show remarkably in a state where the occupancy is sufficiently high under the conditions obtained from the above graph.

In addition, each crystal plane of the negative orientation hardly changes before and after the recrystallization annealing process. Therefore, in order to obtain the bending resistance and the bending resistance, the negative orientation may be controlled so as to satisfy the above relational expression or conditions for the rolled copper foil after the final cold rolling process and before the recrystallization annealing process.

In addition, in the process until the CCL process also serves as a recrystallization annealing process to bond the rolled copper foil to the substrate, the rolled copper foil can be handled in a work hardened state after the cold rolling process, and the rolled copper foil is bonded to the substrate. It may be difficult to cause deformation such as stretching, wrinkles, and bending.

(Surface Processing Process)

Next, the surface processing process is performed to the rolled copper foil bonded to the base material. In the surface processing step, a wiring forming step of forming copper wiring or the like on a rolled copper foil using, for example, etching or the like, and surface treatment such as plating treatment to improve the connection reliability between the copper wiring and other electronic members. In order to protect a copper wiring etc., the surface treatment process performed and the protective film formation process of forming a protective film, such as a solder resist, are covered so that a part of copper wiring may be covered.

The FPC using the rolled copper foil which concerns on this embodiment is manufactured by the above.

<Other embodiments of the present invention>

As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the said embodiment, It can change variously in the range which does not deviate from the summary.

For example, in the said embodiment, although Ag was mainly used as an additive which adjusts the heat resistance of a rolled copper foil, an additive is not limited to what was mentioned by Ag, said representative example, etc. In addition, the various characteristics which can be adjusted with an additive are not limited to heat resistance, You may select an additive suitably according to the various characteristics which need adjustment.

In addition, in the said embodiment, although the CLC process in the manufacturing process of a FPC is what also serves as the recrystallization annealing process with respect to a rolled copper foil, you may make a recrystallization annealing process a process different from a CCL process.

In addition, in the said embodiment, although the rolled copper foil shall be used for FPC use, the use of a rolled copper foil is not limited to this, It can be used for the use which requires bending resistance and bending resistance. Also about the thickness of a rolled copper foil, you may be ultra-thin 10 micrometers or less than 20 micrometers, etc. according to various uses, including a FPC use.

In addition, in the said embodiment, although it was supposed to obtain the outstanding bending resistance by making the total workability in the final cold rolling process (S40) 90% or more, etc., the method of obtaining bending resistance by adjustment of the crystal plane of an azimuth direction differs from this. Can be used independently. In other words, when bending resistance is particularly important and a certain degree of bending resistance may be obtained, the total workability in the final cold rolling process may be less than 90%, for example, 85%, 75%, 65%, and the like. You may also do it.

In the above embodiment, in the detection of the {013} plane and the {023} plane, the measurement by the reflection method is particularly performed among the X-ray exposure method, but may be measured by the transmission method. . In addition to the X-ray PF-Electrification method, you may use the イ ン ｖｅｒｓｅ ピ ｏｌｅ-Ｆｉｇｕｒｅ method or other methods.

In addition, in order to obtain the effect of the present invention, not all of the above-described processes are necessary. Various conditions mentioned in the said embodiment and the Example mentioned later are also illustrations to the last, and it can change suitably.

[Example]

Next, the Example concerning this invention is described with a comparative example.

(1) rolled copper foil using oxygen-free copper

First, the rolled copper foil which concerns on Examples 1-5 and Comparative Examples 1-5 which used oxygen-free copper was produced as follows, and each evaluated variously.

(Production of rolled copper foil)

The rolled copper foil which concerns on Examples 1-5 and Comparative Examples 1-5 was produced in the same procedure and method as the said embodiment using the oxygen-free copper which added Ag by setting the target concentration to 200 mM. In addition, about the comparative examples 1-5, the process etc. which deviate from a structure are included.

Specifically, an ingot having a thickness of 150 mm and a width of 500 mm, prepared by melting and casting a predetermined amount of Ag in oxygen-free copper. In Table 2 below, the analysis values of the Ag concentration in the ingot are analyzed by high frequency inductively coupled plasma (ICP) emission spectroscopic analysis.

[Table 2]

As shown in Table 2, with respect to the target concentration of 200 mM, the analytical value was 180 mm to 220 mm, and both were suppressed by the deviation within about 200 mm ± 20 mm (10%). Ag is originally contained in oxygen-free copper, which is the main raw material, as an unavoidable impurity, in the range of several millimeters to tens of millimeters, and within a range of ± 20 mm due to various causes such as deviations when casting ingots. Non-uniformity is common in the field of metal materials.

Next, in the same procedure and method as in the above embodiment, after obtaining a sheet material having a thickness of 8 mm in the hot rolling process, the cold rolling process and the intermediate annealing process held at a temperature of 750 to 850 degrees for about 2 minutes are repeatedly performed. Copper (dough) of 0.6 mm was produced. The annealing dough was then obtained in the dough annealing process, which was held at a temperature of about 750 degrees for about 2 minutes.

Here, the temperature conditions of each annealing process, etc. matched the heat resistance of the oxygen-free copper material which contains 180 g-220 mm of Ag. Further, different temperature conditions are used in the annealing step for the copper materials having the same composition because the heat resistance changes depending on the thickness of the copper material, and when the copper material is thin, the temperature can be lowered.

Finally, the final cold rolling process was carried out in the same procedure and method as in the above embodiment. The conditions in the final cold rolling process are shown in Table 3 below.

[Table 3]

As shown in Table 3, as the thickness of the plate gradually decreased from the top to the bottom of each table, the conditions were changed like the Uran, and the final cold rolling was performed. That is, the workability and the position of a neutral point per pass | pass of the cold rolling process of 600 micrometers or less in thickness were changed. The position (mm) of the neutral point shown in the right column was shown by the length from the exit side end part of the contact surface of a roll and the annealing dough which is a to-be-processed object to a neutral point.

Moreover, in order to acquire the outstanding bending resistance, in all of Examples 1-5 and Comparative Examples 1-5, conditions were set so that the total workability in the final cold rolling process might be 94% or more. Specifically, the total workability was set to 98% together with Examples 1 to 5 and Comparative Examples 1 to 5. By the above, the rolled copper foil which concerns on Examples 1-5 and Comparative Examples 1-5 whose thickness is 12 micrometers was produced.

Next, the following evaluation was performed about each rolled copper foil produced as mentioned above.

(X-ray diffraction measurement by 2θ / θ method)

First, the 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. The detail of a measuring method is demonstrated below using FIG. 2 is a diagram showing an outline of a measuring method of X-ray diffraction in Examples and Comparative Examples of the present invention.

As shown in Fig. 2, the sample pieces 50 of the rolled copper foil according to Examples 1 to 5 and Comparative Examples 1 to 5 were rotated about three scanning axes of the θ axis, the ψ axis, and the φ axis as described above. Deploy as possible. These three scanning axes are generally called a sample axis, a tilting axis, and an in-plane rotation axis, respectively. In the measurement of the X-ray diffraction in the present embodiment, X-rays (C u Kα) generated when electrons in the L-orbit trajectory transition to the K-orbit by X-ray irradiation with copper (C u) Wire).

In the X-ray diffraction measurement using the 2θ / θ method, a sample piece 50 and a detector not shown in the figure are scanned from the θ axis (rotating about the θ axis) with respect to the incident X-ray. At this time, the scanning angle of the sample piece 50 is called angle (theta), and the scanning angle of a detector is called angle (theta). As a result, as described above, incident X-rays are incident at an angle θ, and diffraction X-rays diffracted at an angle 2θ are detected.

In the present Example and the comparative example, these measurements were performed on the conditions shown in following Table 4 using the X-ray diffraction apparatus (Model: Co., Ltd.) made by Rikaku Co., Ltd. As representative, 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. 3C.

[Table 4]

Next, the 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 were converted into a ratio of 100 in total. And the diffraction peak intensity ratios of the crystal planes were determined. Furthermore, the value regarding said formula (1), ie, the value of (I {022} + I {002}), was calculated | required. In the following Table 5, the diffraction peak intensity ratios I {022}, I {002}, I {113}, of each crystal plane obtained as described above for the rolled copper foils according to Examples 1 to 5 and Comparative Examples 1 to 5, The value of I {111} (formula (2)), I {133}, and the value of formula (1) are shown.

[Table 5]

As described above, in the present example and the comparative example, the degree of workability and the neutral point per pass in the final cold rolling process are changed. As a result, during cold rolling, the ratio of the stress component of the compressive component and the tensile component applied to the workpiece is changed. As a result, the ratio of each crystal surface changes, and the diffraction peak intensity ratio of each crystal surface shown in Table 5 and the value regarding Formula (1) also change.

Moreover, as shown in Table 5, each value of Formula (1) and (2) was all within said predetermined range by the combination of each condition of Examples 1-5.

On the other hand, as for the combination of each condition of Comparative Examples 1-5, one or both values became out of said predetermined range in each value of Formula (1), (2) in some rolled copper foil. In Table 5, the values outside the predetermined ranges are shown in bold underlined text.

(Measurement by X-ray Ｐｏｌｅ-Ｆｉｇｕｒｅ method)

Next, about the rolled copper foil which concerns on Examples 1-5 and Comparative Examples 1-5, the measurement by the X-ray-Fire-Fuig-Curre method was performed. There exist a reflection method which makes the tilt angle (psi) mentioned later into the range of 15 degree-90 degree | times, and the transmission method which makes a range of 0 degree-15 degree | times in the method of such a measurement. In this example, a reflection method was used. 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 method, the sample pieces 50 of the rolled copper foils are arranged as in the X-ray diffraction measurement using the 2θ / θ method.

In the X-ray method, the measurement is performed using the tilt angle ψ defined below. That is, the tilt angle ψ in the direction perpendicular to the sample piece 50 (φ axis direction) is defined as 90 degrees. In addition, the angle formed by the {ｈ'k'l '｝ plane, which is the crystal plane corresponding to the plane of the crystallized {ｈ 기하학적 ｌ} plane geometrically, is called ψ'. At this time, the tilt angle ψ = 90 − ψ 'is defined.

Based on these regulations, the specimen piece 50 is scanned (rotated about the ψ axis) and the tilt angle ψ is changed within a range of 15 degrees or more and 90 degrees or less. That is, the sample piece 50 is inclined at the tilt angle (ψ) within the above range. In this way, while changing the tilt angle ψ, diffraction X-rays are detected at the plurality of tilt angles ψ in the same manner as in the 2θ / θ method. That is, when tilt angle (psi) is 90 degree | times, it measures in principle similarly to 2 (theta) / (theta) method.

In the measurement at each tilt angle ψ, the scanning angle of the detector is fixed to the angle 2θ, and the specimen piece 50 is scanned by the φ axis with respect to the 2θ value of the {h'k'l '｝ plane. (rotate about φ axis), and in-plane rotation angle (phi) is changed within the range of 0 degree | time or more and 360 degrees or less. That is, the sample piece 50 is rotated by in-plane rotation angle (phi) in said range. For the diffraction peaks of the {ｈ'k'l '｝ plane measured in this way, the average intensity of the diffraction peaks within the range of 0 ° to 360 ° is obtained for each tilt angle (ψ). .

At this time, the {ｈ'k'l '｝ plane detected at the predetermined tilt angle ψ corresponds geometrically to the {ｈｋｌ} plane parallel to the rolled surface of the rolled copper foil. In this embodiment, {{{}}} planes to be planted are {013} planes and {023} planes. The {013} plane which has a geometric correspondence with the {013} plane parallel to the rolling surface of a rolled copper foil is a tilt angle (psi) detected in 47 degree | times. Moreover, the geometrical correspondence with the {023} plane parallel to the rolling surface of a rolled copper foil is the {111} plane whose tilt angle (psi) is detected in 53 degree | times.

Therefore, as described above, from the graph of the average strength of the diffraction peaks of the {111} plane obtained by using the X-ray P-Electrification method, it can be determined whether or not the rolled copper foil of this example has a predetermined crystal structure. have.

In the present Example and the comparative example, it measured as mentioned above using the X-ray diffraction apparatus (Model: Co., Ltd. make) of Rikaku Co., Ltd. on the conditions shown in the following Table 6. 4 to 8 show graphs created by showing the average intensities of the diffraction peaks of the {111} plane according to Examples 1 to 5. 9 to 13 show graphs created by showing average intensities of diffraction peaks on the {111} plane according to Comparative Examples 1 to 5. FIG.

[Table 6]

In the graphs of Figs. 4 to 13, the horizontal axis is the tilt angle psi (degrees), and the vertical axis is the diffraction peak intensity (arbitrary unit). In the graph, the average intensities determined by the measurement using the above X-ray P-Elective method are shown. In addition, the graph shows the maximum value of the average intensity of the diffraction peaks of the {111} plane within the range of the graph and the value of that quarter. The graph also shows a straight line connecting the average intensity of the diffraction peaks of the {111} plane at 47 degrees and 53 degrees, respectively, and its longitudinal axis intercept.

As shown in Figs. 4 to 13, in the results of Examples 1 to 5, the longitudinal axis intercept became more than a quarter of the maximum value of the graph, and the above conditions were satisfied. On the other hand, in the results of Comparative Examples 1 to 5, the longitudinal axis intercept was less than a quarter of the maximum value of the graph and did not satisfy the above conditions.

Flexural fatigue life test

Next, in order to investigate the bending resistance of each rolled copper foil, the bending fatigue life test which measured the number of times of repeated bending (bending frequency) until each rolled copper foil was broken was performed. These tests were carried out in accordance with the IC (USA Printed Circuit Industry Association) standard using an FPC high speed bending tester (model: SE-31B2S) manufactured by Shin-Etsu Engineering Co., Ltd. FIG. 14 shows a schematic diagram of a general sliding bending test apparatus 10 including a FPC high speed bending tester manufactured by Shin-Etsu Engineering Co., Ltd., and the like.

First, the rolled copper foils of Examples 1 to 5 and Comparative Examples 1 to 5 were cut into a width of 12.5 mm and a length of 220 mm, and the sample pieces 50 having a thickness of 12 μm were subjected to the recrystallization annealing process at 300 degrees for 60 minutes. Recrystallization annealing was performed. These conditions follow an example of the amount of heat actually received by the rolled copper foil when the flexible printed wiring board is closely contacted with the substrate in the CCL process.

Next, as shown in FIG. 14, the sample piece 50 of the rolled copper foil was fixed to the sample fixing plate 11 of the sliding bending test apparatus 10 with the screw 12. As shown in FIG. Subsequently, the sample piece 50 is brought into contact with the vibration transmitting part 13 to be attached thereto, and the vibration transmitting part 13 is vibrated up and down by the oscillation driving body 14, so that the sample piece 50 is attached. Vibration was transmitted to and the fatigue fatigue life test was performed. As the measurement conditions of the bending fatigue life, the bending radius 10r was 1.5 mm, the stroke 10s was 10 mm, and the amplitude number was 25 Hz. Under these conditions, five sample pieces 50 cut out from each rolled copper foil were measured, and the average value of the number of times of bending until breakage occurred was compared. The results are shown in Table 7 below.

[Table 7]

As shown in Table 7, in Examples 1-5 and Comparative Examples 3 and 5, since all of said Formula (1) was satisfied, the high flex resistance of 2 million times or more was obtained. On the other hand, in Comparative Examples 1, 2, and 4, which did not satisfy the above formula (1), the number of bendings was less than 2 million times.

It should be noted here that even in Comparative Examples 1, 2, and 4, they have a relatively high level of flex resistance. This is because, for example, the final cold rolling process having a total workability of 94% or more, specifically 98% of total workability in the above-described Patent Document 3 and the like is performed. In Examples 1 to 5, the flex resistance was further improved by satisfying the above formula (1).

(Evaluation of bending resistance)

Then, the bending resistance of each rolled copper foil was investigated. In the standard of the general test regarding the bending resistance, there is no standardization regarding the bending of 180 degrees required for, for example, FPC use. Therefore, a bending test was performed to measure the number of bending times until cracking occurred in each rolled copper foil by the method shown in FIG.

That is, first, recrystallization annealing was performed at 300 degrees for 60 minutes on the sample piece 50 which cut out the rolled copper foil which concerns on Examples 1-5 and Comparative Examples 1-5 to 15 mm in width and 100 mm in length with respect to a rolling direction. Next, as shown in FIG. 15, the sample piece 50 was bent 180 degrees so as to surround the spacer 20 having a thickness of 0.25 mm, and the bent portion was observed with a metal microscope in this state to confirm the presence of cracking. . If there is no break, the rolled copper foil returns from the bent state to the original unfolded state. This cycle was repeated, and the cycle was repeated until the crack generate | occur | produced, and the number of bending was measured, observing the bent part for every 5 cycles of the sample piece 50 cut out from each rolled copper foil. The results are shown in Table 8 below.

[Table 8]

As shown in Table 8, in any of Examples 1 to 5 which satisfies the conditions obtained from the above formula (2) and the graph together, the number of bending times was 100 or more, and excellent bending resistance was obtained.

On the other hand, except for Comparative Example 4, neither of the formulas (2) and the above conditions was satisfied in any of the Comparative Examples including Comparative Examples 3 and 5, which showed excellent bending resistance, so that the bending frequency was less than 100 times. Sufficient bending resistance was not obtained. However, about the comparative example 4 which satisfy | fills only Formula (2), the number of bending was 61 times, and compared with the other comparative example, the slight improvement was recognized.

(2) Rolled copper foil using tough pitch copper

Next, the rolled copper foil which concerns on Example 6 and Comparative Examples 6 and 7 whose thickness is 12 micrometers was produced by the same procedure and method as the said Example using the tough pitch copper which added Ag by setting the target concentration to 200 mM. However, the comparative examples 6 and 7 include processing out of the configuration, and the like.

The Ag concentration in the ingot of Example 6 and Comparative Examples 6 and 7 was 190 mm, 204 mm, and 199 mm, respectively, by the analysis value obtained by the IP emission spectrometry. All are uneven within ± 10% and are common in the field of metal materials. In addition, according to the heat resistance of the tough pitch copper material containing Ag of such a density | concentration, the conditions different from the above conditions were used in the intermediate annealing process and the dough annealing process. Specifically, in the intermediate annealing process, the temperature was maintained for about 2 minutes to 4 minutes at a temperature of 650 ° C to 750 ° C, and for about 2 minutes at the temperature of about 700 ° in the dough annealing process. In addition, the conditions of Table 3 above were also applied in the final cold rolling process for the present example and the comparative example.

About the rolled copper foil which concerns on Example 6 and Comparative Examples 6 and 7 which were produced as mentioned above, X-ray diffraction measurement by the 2Theta / Theta method and the X-ray-Fireium-Fireium method are performed by the same method and procedure as the above-mentioned Example. It measured, calculated | required said Formula (1), (2), and created the graph as above. 16 to 18 show graphs of Example 6 and Comparative Examples 6 and 7, respectively, which were prepared using the X-ray process-fired method. Table 9 below shows the results of X-ray diffraction measurements by the 2θ / θ method.

[Table 9]

As shown in Table 9 and FIGS. 16-18, about the rolled copper foil which concerns on Example 6. Equations (1) and (2) were satisfied, and the conditions specified from the graph of average intensity were also satisfied. On the other hand, about the rolled copper foil which concerns on the comparative example 6, it satisfy | fills Formula (1), but it was out of the predetermined range of Formula (2), and was also out of the conditions prescribed | regulated from a graph. In addition, about the rolled copper foil which concerns on the comparative example 7, Formula (2) was in the predetermined range, but was deviated from the conditions prescribed | regulated from Formula (1) and a graph. In Table 9, the values outside the predetermined ranges are shown in bold underlined text.

In addition, about the rolling copper foil which concerns on Example 6 and Comparative Examples 6 and 7, the bending fatigue life test was done by the method and procedure similar to the said Example. As a result, about Example 6 and Comparative Example 6 which satisfy | fill said Formula (1), high bending resistance of 2,131,000 times and 2,098,000 times, respectively, which is 2 million times or more was obtained. On the other hand, in the comparative example 7 which does not satisfy said Formula (1), the number of bending was 1,688,000 times, resulting in less than 2 million times.

Moreover, the bending test was done about the rolled copper foil which concerns on Example 6 and Comparative Examples 6 and 7, in the same method and procedure as the said Example. As a result, although the number of bendings was good for 98 times in Example 6, a slight improvement was observed for Comparative Example 7, which satisfies Equation (2), 39 times for Comparative Example 6, but all 50 times. The result was a fall.

The above results are shown in Table 10 below. In Table 10, the values outside the predetermined ranges are indicated by underlined bold letters.

[Table 10]

As mentioned above, when each crystal surface was in the predetermined range, it turned out that the favorable bending resistance is also acquired about the rolled copper foil which uses tough pitch copper as a main raw material, and it can aim at the improvement of bending resistance.

(3) Rolled Copper Foil Using Other Additives

Next, in the same procedure and method as in the above example, Example 7 having a thickness of 12 µm using an oxygen-free copper obtained by adding Ag and a target concentration of 40 mM and titanium (Ti) as an additive. The rolled copper foil which concerns on the comparative examples 8 and 9 was produced. However, for the comparative examples 8 and 9, processing out of the configuration and the like are included.

Ag concentrations in the ingots of Example 7 and Comparative Examples 8 and 9 were 117 mm, 121 mm and 120 mm, respectively, as analyzed values obtained by the ICP emission spectrometry. The Ti concentrations were 39 mm, 38 mm and 39 mm, respectively. All are uneven within ± 10% and are common in the field of metal materials.

In addition, in accordance with the heat resistance of the oxygen-free copper material containing Ag and Ti of such concentration, conditions different from the above conditions were used in the intermediate annealing step and the dough annealing step. Specifically, in the intermediate annealing step, the temperature was maintained between about 1 minute and 3 minutes at a temperature of 650 ° C to 750 ° C, and in the dough annealing step, the temperature was maintained at about 700 ° C for about 1 minute. In addition, also about the present Example and the comparative example, the conditions of said Table 3 were applied in the final cold rolling process.

About the rolled copper foil which concerns on Example 7 and Comparative Examples 8 and 9 which were produced as mentioned above, X-ray diffraction measurement by the 2 (theta) / (theta) method using the same method and procedure as the said Example, and using the X-ray peak-figure method It measured, calculated | required said Formula (1), (2), and created the graph as above. In Table 11 below, the results of X-ray diffraction measurements by the 2θ / θ method are shown.

[Table 11]

As shown in Table 11, for the rolled copper foil according to Example 7, the relationship between the diffraction peak intensities of the respective crystal faces satisfies the equations (1) and (2), and is not shown in the figure, but from the graph of the average strength The prescribed conditions were also met. On the other hand, about the rolled copper foil which concerns on the comparative example 8, both Formula (1) and (2) were out of range, and although it is not shown in figure, it also escaped from the conditions prescribed | regulated from a graph. Moreover, about the rolled copper foil which concerns on the comparative example 9, although Formula (1) and (2) existed in the predetermined range, it deviated from the conditions prescribed | regulated from the graph which is not shown in drawing. In Table 11, the values outside the predetermined ranges are indicated by underlined bold letters.

In addition, about the rolling copper foil which concerns on Example 7 and Comparative Examples 8 and 9, the bending fatigue life test was done by the method and procedure similar to the said Example. As a result, about Example 7 and Comparative Example 9 which satisfy | fill said Formula (1), high bending resistance of 2,143,000 times and 2,122,000 times, respectively, which is 2 million times or more was obtained. On the other hand, in the comparative example 8 which does not satisfy both said Formula (1) and (2), the number of bending was 1,701,000 times, resulting in less than 2 million times.

Moreover, the bending test was done about the rolled copper foil which concerns on Example 7 and Comparative Examples 8 and 9 by the method and procedure similar to the said Example. As a result, although the number of bendings was good for 101 times in Example 7, a slight improvement was observed for Comparative Example 9 that satisfies Equation (2), 36 times for Comparative Example 8, but 51 times for all. The result was a fall.

The above results are shown in Table 12 below. In Table 12, the values outside the predetermined ranges are shown in bold underlined text.

Table 12

As mentioned above, when each crystal surface was in the predetermined range, also with respect to the rolled copper foil which added other additives, such as Ag and Ti, it turned out that favorable bending resistance and bending resistance are obtained.

<Consideration by the inventor, etc.>

The discussion by the present inventors about the structure of control of the crystal plane of the negative orientation in the manufacturing process of said rolled copper foil is demonstrated below.

(1) About crystal rotation

As described above, the compressive stress and the tensile stress weaker than the compressive stress are applied to the copper material during the rolling process such as the final cold rolling process. The copper crystals in the rolled copper material cause rotational phenomenon to the {022} plane due to the stress during the rolling process, and together with the progress of the rolling process, a rolling aggregate structure in which the orientation of the crystal plane parallel to the rolling plane is mainly the {022} plane is formed. do. At this time, as described above, the path of rotation toward the {022} plane is changed by the ratio of the compressive stress and the tensile stress. This will be described with reference to FIG.

Fig. 19 is a reverse polarity diagram of the pure copper metal quoted from the following Technical Document 1, (a) is a reverse polarity diagram showing the crystal rotation direction due to tensile deformation, and (b) is a crystal rotation due to compression deformation. It is an inverse pole figure showing a direction. In the reverse polarity diagram, the {002} plane is referred to as the {001} plane, and the {022} plane is referred to as the {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 represented by the {011} plane which is the minimum value of the plane parallel to the {022} plane.

Technical Document 1: Author Nagashima Shinichi, "Organization", Maruzen Corporation, January 20, 1984, Figure 2.52 (a), (c) of p96

As shown in Fig. 19, the copper crystal in the copper material rotates toward the {111} plane only by the deformation by the tensile stress, and rotates toward the {011} plane by the deformation only by the compressive stress. In the rolling process, since the compressive and tensile components are combined, the crystal rotation direction is not so simple. However, the compressive component is predominantly deformed than the tensile component and is deformed and rolled, so that the crystal rotation toward the {011} plane usually occurs, and the {111} plane is also partially rotated by the ratio of the compressive component and the tensile component. At this time, since the compression component is dominant, crystal rotation also occurs in which the crystal which started to rotate to the {111} plane is returned to the {011} plane. On the contrary, in some cases, the crystal rotating toward the {011} plane or the crystal reaching the {011} plane may rotate toward the {133} plane or the {111} plane by the tension component.

As described above, when crystal rotation occurs while the compressed component and the tensile component are mixed while maintaining the relationship of the compressed component> tensile component, the crystal plane of the kitchen plate becomes the {011} plane, and the mixture of the compressed component and the tensile component As a result of the crystal rotation, the crystal plane of the negative orientation is considered to be the {001} plane, the {113} plane, the {111} plane, and the {133} plane.

The crystal orientations of the reverse pole viscosity shown in Fig. 20 are general, but the {013} planes, {023} planes, and the crystal planes of the crystal planes of which the orientation difference is relatively small are further shown in the figure. As shown in Fig. 20, in the crystal rotation by the compressive stress, the plane rotates to the {011} plane ({022} plane) via the {013} plane, the {023} plane, and the like.

In the rolling process, as described above, unless both the compressive stress and the tensile stress weaker than the compressive stress are added to the rolled copper material, it cannot be rolled while maintaining the shape of the copper material. That is, the compressive stress alone becomes radially expanded and widened like a simple press work. On the premise that the compressive stress> tensile stress, the crystal rotated toward the {111} plane due to the influence of the tensile stress or the remaining of the orientation in which the rotation did not reach the {022} plane becomes negative orientation. As described above, the {111} plane deteriorating the bending resistance is a negative orientation formed by tensile stress, and the {013} plane or {023} plane which improves the bending resistance is a negative orientation formed by compressive stress.

Therefore, in order to suppress as much as possible the occupancy of the {111} plane on the rolled surface of the rolled copper foil and to increase the occupancy of the {013} plane or the {023} plane as much as possible, while adjusting the balance between the compressive stress and the tensile stress as appropriate. Rolling becomes important.

(2) Control in the final cold rolling process

The compression component and the tension component can be controlled by changing the rolling conditions per one pass during rolling, for example, as is also done in the final cold rolling step (S40) according to the above embodiment. That is, as attempted in the above embodiments and examples, for example, attention can be paid to changes in the degree of processing per one pass.

In addition, in the said embodiment and an Example, the position control of a neutral point is also performed in addition to the workability per pass in a final cold rolling process. In other words, in the adjustment of the control parameters of the compression component and the tension component, for example, the positional change of the neutral point may be taken into account.

The control factors such as the degree of workability 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, the method of adding the compressive stress to the copper material by the difference in the number of rolls, the total number of rolls, the combination of the rolls, the roll configuration such as the diameter and material of each roll, and the surface state (surface roughness), etc. Differences in friction coefficients occur. If the rolling mills are different, the absolute values of the respective control factors for the conditions in the above-described embodiments may also be adjusted appropriately for each rolling mill. Also in the same rolling mill, when the surface state of the rolling roll or the material of the rolling roll is different, the absolute value of each control factor is different. Therefore, even if it is the same rolling mill, it can adjust suitably according to each state.

In the said embodiment and an Example, although the position of the neutral point was controlled as a control factor whose workability was variable, control using control factors other than workability is also possible.

For example, if the workability per one pass is made constant and the surface roughness of the rolling roll is changed, the friction coefficient received by 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) other control factors

In addition, in the said embodiment and Example, although the rotation direction and rotation path of the copper crystal were controlled by the rolling conditions in the final cold rolling process, the same control is possible also in another process.

For example, the rolling conditions of the final cold rolling process are made constant, and the conditions of the manufacturing process up to immediately before the final cold rolling process are also affected, thereby affecting the final cold rolling process, and the rotational direction and the rotation path in the final cold rolling process. It is thought that it is possible to change indirectly. However, if the rolling conditions in the final cold rolling process are changed as in the above embodiments and examples, the direction of rotation and the path of rotation can be directly controlled and the controllability can be further improved.

Thus, the state of the crystal orientation of the rolled copper foil after a final cold rolling process is not limited by the specific manufacturing method. It is because the state of the crystal orientation of the rolled copper foil can be controlled by various methods, and the method exists in various ways.

10 Sliding Bending Tester
11 Sample fixing plate
12 Screw
13 Vibration Transmitter
14 oscillating drive
20 spacer
50 sample piece

Claims (6)

Rolled copper foil after the final cold rolling process and before the recrystallization annealing process, having a major surface, and having a plurality of crystal surfaces parallel to the major surface. (I)
Wherein the plurality of crystal planes include {022} plane, {002} plane, {113} plane, {111} plane and {133}
The diffraction peak intensity ratios of the respective crystal surfaces obtained from the X-ray diffraction measurements using the 2θ / θ method on the main surface and converted to a total value of 100 are each I {022). }, I {002}, I {113}, I {111} and I {133}
I {022} + I {002｝ ≥ 80.0,
I {111｝ ≤ 5.0,
For each of the plurality of tilt angles within the range of 15 degrees to 90 degrees, the in-plane rotation angle of the main surface is within the range of 0 degrees to 360 degrees using the X-ray process Obtain the average intensity of the diffraction peaks of the {111} plane
When the graph showing the average intensity of the diffraction peaks of the {111} plane was made with the tilt angle as the horizontal axis and the diffraction peak intensity as the vertical axis,
The longitudinal axis intercept of the straight line connecting the average intensity of the diffraction peak of the {111} plane with the tilt angle at 47 degrees and the average intensity of the diffraction peak of the {111} plane with the tilt angle at 53 degrees is A rolled copper foil, characterized in that the tilt angle is not less than a quarter of the maximum value of the average intensity of the diffraction peaks of the {111} plane within a range of 15 degrees to 90 degrees.
The method of claim 1,
A rolled copper foil comprising oxygen free copper or tough pitch copper (TPC: Tough-Pitch Copper) as a main component.
3. The method according to claim 1 or 2,
At least one of silver, boron, titanium, and tin is added, The rolled copper foil characterized by the above-mentioned.
The method according to any one of claims 1 to 3,
The rolled copper foil whose thickness is 20 micrometers or less.
The method according to any one of claims 1 to 4,
Rolled copper foil, characterized in that the total workability in the final cold rolling process is 90% or more.
6. The method according to any one of claims 1 to 5,
Rolled copper foil for use in flexible printed wiring boards.

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