JP2014058705A - Rolled copper foil and copper-clad laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolled copper foil having flexibility stably.SOLUTION: A maximum value Ia out of 4 values represented by (1) a maximum value I(0,0) of a strength in the first area surrounded by (φ1,Φ)=(0°,0°), (10°,0°), (0°,10°) and (10°,10°), (2) a maximum value I(90,0) of a strength in the second area surrounded by (φ1,Φ)=(80°,0°), (90°,0°), (80°,10°) and (90°,10°), (3) a maximum value I(0,90) of a strength in the third area, and (4) a maximum value I(90,90) of a strength in the fourth area, is 100 or more at φ2=0° in terms of an Euler angle (φ1,Φ,φ2) when positive pole point determination of a surface after annealing at 200°C for 0.5 hours and recrystallization is performed.

Description

  The present invention relates to a rolled copper foil and a copper clad laminate suitable for a copper clad laminate, for example, used in a flexible printed circuit (FPC).

  A flexible wiring board (FPC) is formed by laminating a resin layer and a copper foil, and is preferably used for repeated bent portions. As copper foil used for such FPC, rolled copper foil excellent in flexibility is widely used. As a method for improving the flexibility of the rolled copper foil, a technique for developing a cubic texture after recrystallization annealing has been reported (Patent Document 1). In addition, as a method for developing a cube texture after recrystallization annealing, there are specified the final rolling degree and rolling conditions (Patent Document 2), and leaving the cube orientation after rolling (Patent Document 3). Yes.

Japanese Patent No. 3009383 JP 2009-185376 A JP 2010-150597 A

However, the conventional method for developing a cube texture is to adjust the final rolling work degree, the thickness of the copper foil material at the time of annealing before final rolling in which the cube texture grows is changed according to the thickness of the final product, It is necessary to perform rolling under special conditions, and there is a problem that productivity decreases.
Conventionally, the degree of development of the cubic texture has been evaluated using the X-ray diffraction intensity of the {200} plane of the copper foil surface. However, since the stress when the copper foil is actually deformed by bending is in the in-plane direction of the copper foil, when considering the direct influence on the flexibility of the copper foil, the orientation of the three-dimensional crystal orientation in the material Is a problem.

  That is, this invention is made | formed in order to solve said subject, and it aims at provision of the rolled copper foil and copper clad laminated board which can obtain the outstanding flexibility stably.

As a result of various studies, the present inventors have found that excellent flexibility can be obtained when the entire copper foil is oriented three-dimensionally in a specific crystal orientation.
That is, the rolled copper foil of the present invention was subjected to a positive electrode point measurement using an X-ray diffraction method on the surface after being recrystallized by heating at 200 ° C. for 0.5 hour, and the crystal [001] orientation and material ND When the rotation angle about the direction perpendicular to the plane including the direction is Φ, the rotation angle about the ND direction is φ1, and the rotation angle about the [001] direction is φ2, the ND axis is After rotating by φ1 as the rotation axis, it is rotated by φ in order to make the ND axis and z axis coincide with each other, and finally by rotating by φ2 around the [001] axis, the ND, TD, RD of the material and the crystal For Euler angles (φ1, Φ, φ2), which are pairs of angles that coincide with [001], [010], [100], at φ2 = 0 °, (1) (φ1, Φ) = (0 °, Within the first region surrounded by (0 °), (10 °, 0 °), (0 °, 10 °), (10 °, 10 °) Intensity values I (0,0) and (2) (φ1, Φ) = (80 °, 0 °), (90 °, 0 °), (80 °, 10 °), (90 °, (3) (φ1, Φ) = (0 °, 80 °), (0 °, 90 °), (0 °, 90 °), (2) 10 °, 80 °), maximum intensity I (0, 90) in the third region surrounded by (10 °, 90 °) and (4) (φ1, Φ) = (80 °, 80 ° ), (80 °, 90 °), (90 °, 80 °), and the maximum value I (90, 90) in the fourth region surrounded by (90 °, 90 °). The maximum value Ia among the four values is 100 or more.

  Further, the rolled copper foil of the present invention has a positive electrode point measurement using an X-ray diffraction method on the surface, and a rotation angle about a direction perpendicular to a plane including the [001] orientation of the crystal and the ND direction of the material. Φ, the rotation angle about the ND direction as φ1, and the rotation angle about the [001] direction as φ2, after rotating the ND axis by φ1 as the rotation axis, the ND axis and the z axis Is rotated by Φ and finally rotated by φ2 around the [001] axis so that the ND, TD, RD of the material and the [001], [010], [100] of the crystal match. For Euler angles (φ1, Φ, φ2), which are pairs of angles, at φ2 = 0 °, (1) (φ1, Φ) = (0 °, 0 °), (10 °, 0 °), (0 ° , 10 [deg.], (10 [deg.], 10 [deg.]), The maximum intensity I (0,0) in the first region, and (2) ([phi] 1, [Phi] = Maximum value I of intensity (90, 0) in the second region surrounded by (80 °, 0 °), (90 °, 0 °), (80 °, 10 °), (90 °, 10 °) ) And (3) (φ1, Φ) = (0 °, 80 °), (0 °, 90 °), (10 °, 80 °), (10 °, 90 °) Intensity values I (0, 90) and (4) (φ1, Φ) = (80 °, 80 °), (80 °, 90 °), (90 °, 80 °), (90 ° , 90 °), the maximum value Ia (90, 90) in the fourth region surrounded by the fourth region is 100 or more.

It is preferable that a ratio Ia / Ib between the maximum value Ia and the maximum value Ib of the intensity at any measurement point excluding the first region to the fourth region at φ2 = 0 ° is 5 or more.
The ratio Ia / Ib is preferably 4 or more before final cold rolling and after recrystallization annealing.
When the final cold rolling degree is η, and η = ln {(thickness before final cold rolling) / (thickness after final cold rolling)}, it is preferable that η ≧ 2.3.

  The copper clad laminate of the present invention comprises the copper foil and resin.

  According to the present invention, a rolled copper foil and a copper clad laminate having excellent flexibility can be obtained stably.

It is a figure which shows Euler angles ((phi) 1, (phi), (phi) 2). It is a figure which shows 1st area | region (I), 2nd area | region (II), 3rd area | region (III), and 4th area | region (IV). It is a figure which shows the method of measuring a bending fatigue life with a bending test apparatus.

  Hereinafter, the rolled copper foil which concerns on embodiment of this invention is demonstrated. Since the rolled copper foil according to the embodiment of the present invention is excellent in flexibility, it can be suitably used for a copper-clad laminate and exhibits high resistance to repeated deformation. Etc. are also suitable.

<Ingredient composition>
As the component composition of the copper foil, tough pitch copper (TPC) standardized to JIS-H3100 (C1100) or JIS-H3100 (C1020) oxygen-free copper (OFC) can be suitably used. Further, Sn as an additive element may be contained in an amount of 10 to 200 ppm by mass and / or Ag may be contained in an amount of 10 to 500 ppm by mass, and the remainder may be made of tough pitch copper or oxygen-free copper.
Further, 10 to 500 mass in total of at least one element selected from the group consisting of Ag, Sn, In, Ti, Zn, Zr, Fe, P, Ni, Si, Te, Cr, Nb, B, and V as additive elements. It may contain ppm, and the balance may be tough pitch copper or oxygen-free copper.
In addition, since the rolled copper foil used for FPC is requested | required of flexibility, the thickness of a rolled copper foil has preferable 20 micrometers or less. The lower limit of the thickness of the rolled copper foil is not particularly limited, but in consideration of manufacturability, for example, 4 μm or more is preferable, and more preferably 5 μm or more.

<Crystal orientation of copper foil>
In the rolled copper foil according to the first embodiment of the present invention, the surface after being recrystallized by heating at 200 ° C. for 0.5 hour is subjected to positive electrode spot measurement using an X-ray diffraction method, and [001 The rotation angle about the direction perpendicular to the plane including the orientation and the ND direction of the material is expressed as Φ, the rotation angle about the ND direction as φ1, and the rotation angle about the [001] direction as φ2. In the case of Euler angles (φ1, Φ, φ2) at φ2 = 0 °,
(1) Intensity within the first region surrounded by (φ1, Φ) = (0 °, 0 °), (10 °, 0 °), (0 °, 10 °), (10 °, 10 °) Maximum value I (0,0),
(2) Strength in the second region surrounded by (φ1, Φ) = (80 °, 0 °), (90 °, 0 °), (80 °, 10 °), (90 °, 10 °) Maximum value I (90,0),
(3) Strength in the third region surrounded by (φ1, Φ) = (0 °, 80 °), (0 °, 90 °), (10 °, 80 °), (10 °, 90 °) Maximum value I (0,90),
(4) Strength in the fourth region surrounded by (φ1, Φ) = (80 °, 80 °), (80 °, 90 °), (90 °, 80 °), (90 °, 90 °) Maximum value I (90,90),
The maximum value Ia among the four values represented by is 100 or more.

In addition, the rolled copper foil according to the second embodiment of the present invention performs positive point measurement on the surface that is not heated at 200 ° C. for 0.5 hour using the X-ray diffraction method, and the [001] orientation of the crystal When the rotation angle about the direction perpendicular to the plane including the ND direction of the material is Φ, the rotation angle about the ND direction is φ1, and the rotation angle about the [001] direction is φ2 For Euler angles (φ1, Φ, φ2), at φ2 = 0 °,
(1) Intensity within the first region surrounded by (φ1, Φ) = (0 °, 0 °), (10 °, 0 °), (0 °, 10 °), (10 °, 10 °) Maximum value I (0,0),
(2) Strength in the second region surrounded by (φ1, Φ) = (80 °, 0 °), (90 °, 0 °), (80 °, 10 °), (90 °, 10 °) Maximum value I (90,0),
(3) Strength in the third region surrounded by (φ1, Φ) = (0 °, 80 °), (0 °, 90 °), (10 °, 80 °), (10 °, 90 °) Maximum value I (0,90),
(4) Strength in the fourth region surrounded by (φ1, Φ) = (80 °, 80 °), (80 °, 90 °), (90 °, 80 °), (90 °, 90 °) Maximum value I (90,90),
The maximum value Ia among the four values represented by is 100 or more.
The rolled copper foil according to the first embodiment is shipped without recrystallization without heating corresponding to 0.5 hours at 200 ° C. after the final cold rolling in the copper foil manufacturing process, It assumes a copper foil in a shipping state when it is supplied to a copper clad laminate manufacturing process. On the other hand, the rolled copper foil according to the second embodiment is shipped after being recrystallized by heating corresponding to 0.5 hours at 200 ° C. after the final cold rolling in the copper foil manufacturing process. It assumes a copper foil in a shipping state when supplied to a manufacturing process of a laminated board.

Here, as shown in FIG. 1, the Euler angles (φ1, Φ, φ2) are rotated by φ1 with the ND axis as a rotation axis, and then rotated by Φ to match the ND axis and the z axis, Finally, a pair of angles (φ1, Φ, φ2) in which the ND, TD, RD of the material and the [001], [010], [100] of the crystal coincide with each other by rotating by φ2 around the [001] axis. Say. Euler angles (φ1, Φ, φ2) are represented by the Bunge method shown in FIG. “RD” is the rolling direction, “ND” is the direction perpendicular to the rolling surface, and “TD” is the width direction.
Further, the first region (I), the second region (II), the third region (III), and the fourth region (IV) are shown in FIG. That is, each of the first region (I) to the fourth region (IV) is a square region having φ1 and Φ of 10 degrees on each side.
When Ia is less than 100, the ratio of crystal grains having orientations other than those included in the first region (I) to the fourth region (IV) increases, and the stress application direction and the slip direction are close when bent. For this reason, slip deformation is unlikely to occur, and the flexibility tends to decrease.
The upper limit of Ia is not particularly limited, but is typically 250 or less, and more typically 200 or less.

  Furthermore, the ratio Ia / Ib between Ia and the maximum intensity value Ib at any measurement point (that is, the φ1-Φ plane in FIG. 2) at φ2 = 0 ° excluding the first region to the fourth region is 5 If it is above, since the ratio of the crystal grains having the orientation included in the first region (I) to the fourth region (IV) is increased, the flexibility is further improved. The higher the ratio Ia / Ib, the higher the flexibility, but typically a value of 25 or less.

<Manufacture of rolled copper foil>
The rolled copper foil of the present invention can be produced by subjecting an ingot to hot rolling, cold rolling and annealing, and then cold rolling before annealing, recrystallization annealing, and final cold rolling.
Here, the material after recrystallization annealing is preferably manufactured by final cold rolling at a workability of η of 2.3 or more. When η is less than 2.3, the Ia of the rolled copper foil may be less than 100, or the Ia / Ib may be less than 5.
In addition, when the final rolling work degree is η, the work degree is represented by η = ln {(thickness before final cold rolling) / (thickness after final cold rolling)}.
Further, it is desirable to adjust the recrystallization annealing conditions before the final cold rolling so that the ratio Ia / Ib is 4 or more in the sample before the final cold rolling and after the recrystallization annealing. The upper limit of the ratio Ia / Ib of the sample before final cold rolling and after recrystallization annealing is not particularly limited, but is typically 10 or less.

  Specifically, in order to control Ia / Ib before the final cold rolling to 4 or more, it is preferable that the rate of temperature increase during recrystallization annealing before the final cold rolling is 5 to 50 ° C./s. If the heating rate is too high, the crystal orientation becomes random and Ia / Ib decreases. If the rate of temperature increase is too slow, the productivity is lowered.

  First, a copper ingot having the composition shown in Table 1 was manufactured and hot-rolled to a thickness of 10 mm. Then, after repeating cold rolling and annealing 1 or more times, it cold-rolled to predetermined thickness, Then, it recrystallized annealing with the annealing furnace set to the temperature of 700-800 degreeC. Furthermore, the final cold rolling was performed at a workability (η) shown in Table 2 to obtain a copper foil having a thickness shown in Table 1. Table 2 shows the rate of temperature increase during recrystallization annealing before final cold rolling and η during final cold rolling.

<Orientation degree>
The copper foil sample obtained by final cold rolling was recrystallized by heating at 200 ° C. for 0.5 hour, and then the positive electrode spot measurement on the surface of the sample was performed using the X-ray diffraction method. The X-ray diffractometer was measured by the Schulz reflection method using RINT-2000 manufactured by Rigaku Corporation. The measurement conditions are as follows.
X-ray source: copper, acceleration voltage: 30 kV, tube current: 100 mA, diverging slit: 1/2 °
Divergence length restriction slit: 1.2 mm, scattering slit: 4 mm, light receiving slit: 4 mm
α angle step: 5 °, β angle step: 5 °, counting time: 2 seconds / step The crystal orientation distribution function of the crystal analysis program (product name: Standard) manufactured by Norm Engineering Co., Ltd. is used from the obtained measurement results. The maximum values I (0,0), I (90,0), I (0,90), and I (90,90) of the first region (I) to the fourth region (IV) are obtained, respectively. The maximum value Ia was determined from the four maximum values. Further, Ib was obtained.
Ia and Ib were similarly calculated | required also about the said sample before refining annealing in the annealing furnace set to the temperature of 700-800 degreeC before final cold rolling.
Note that the same result was obtained even when the step angle of the α angle and β angle in the positive electrode point measurement was set to a smaller value (for example, 1 °). However, since the measurement takes a long time, the step angle is actually 5 °. Is appropriate.

<Flexibility>
After the copper foil sample obtained by final cold rolling was recrystallized by heating at 200 ° C. for 0.5 hour, the bending fatigue life was measured by a bending test apparatus shown in FIG. This apparatus has a structure in which a vibration transmitting member 3 is coupled to an oscillation driver 4, and a copper foil 1 to be tested is fixed to the apparatus at a total of four points including a screw 2 part indicated by an arrow and a tip part of 3. Is done. When the vibration part 3 is driven up and down, the intermediate part of the copper foil 1 is bent into a hairpin shape with a predetermined radius of curvature r. In this test, the number of times until breakage when bending was repeated under the following conditions was determined.
The test conditions are as follows: Specimen width: 12.7 mm, Specimen length: 200 mm, Specimen sampling direction: Collected so that the length direction of the specimen is parallel to the rolling direction, curvature radius r : 1.5 mm, vibration stroke: 20 mm, vibration speed: 1000 times / min.
Further, the flexibility was evaluated according to the following criteria. If evaluation is (double-circle), (circle), or (triangle | delta), flexibility is favorable.
◎: The number of bendings is 200,000 times or more and the flexibility is the best. ○: The number of bendings is 100,000 or more and less than 200,000 times, and the flexibility is good. △: The number of bendings is 50,000 or more and less than 100,000. , Excellent flexibility ×: less than 50,000 times of bending, poor flexibility

Tables 1 and 2 show the evaluation results of the copper foil and the manufacturing conditions of the copper foil.
Here, “TPC” in the composition column in Table 1 represents tough pitch copper (TPC) standardized to JIS-H3100 (C1100), and “OFC” represents oxygen-free copper (OFC) standardized to JIS-H3100 (C1020). Represents. Therefore, for example, “190 ppmAg-TPC” in the composition column in Table 1 means a composition in which 190 mass ppm of Ag is added to tough pitch copper (TPC) standardized to JIS-H3100 (C1100). In addition, “100 ppm Sn—OFC” in the composition column of Table 1 means a composition in which 100 mass ppm of Sn is added to oxygen-free copper (OFC) specified in JIS-H3100 (C1020).

  As is clear from Table 1, Ia was 100 or more, and in each of the examples, the flexibility was excellent. In particular, in each example where Ia / Ib satisfies 5 or more, the flexibility was particularly excellent.

  On the other hand, in Comparative Examples 1 to 4 where Ia was less than 100, the flexibility was inferior.

As apparent from Table 2, in each example, the ratio Ia / Ib was 4 or more in the sample before the final cold rolling and after the recrystallization annealing. In addition, Example 23 in which η was less than 2.3 had lower flexibility after heating the copper foil sample at 200 ° C. for 0.5 hours than other examples in which η was 2.3 or more. became.
On the other hand, in the case of Comparative Examples 1 to 4 in which the temperature increase rate during recrystallization annealing exceeded 50 ° C./s, the ratio Ia / Ib was less than 4 in the sample before the final cold rolling and after recrystallization annealing. became. Therefore, in Comparative Examples 1 and 3 in which the final cold rolling degree η is less than 2.3, and in Comparative Examples 2 and 4 in which the final cold rolling degree η is 2.3 or more, the copper foil is 200 ° C. Ia after heating for 0.5 hour was less than 100 and Ia / Ib was less than 5, and as a result, sufficient flexibility was not obtained.

Claims (6)

The surface after being recrystallized by heating at 200 ° C. for 0.5 hours is subjected to positive electrode spot measurement using an X-ray diffraction method,
The rotation angle about the direction perpendicular to the plane including the [001] orientation of the crystal and the ND direction of the material is Φ, the rotation angle about the ND direction is φ1, and the rotation angle about the [001] direction is When written as φ2,
After rotating by φ1 with the ND axis as the rotation axis, it is rotated by φ to match the ND axis and the z axis, and finally rotated by φ2 around the [001] axis, so that the materials ND, TD, RD And Euler angles (φ1, Φ, φ2), which is a set of angles at which [001], [010], and [100] of the crystal coincide with each other, at φ2 = 0 °,
(1) Intensity within the first region surrounded by (φ1, Φ) = (0 °, 0 °), (10 °, 0 °), (0 °, 10 °), (10 °, 10 °) Maximum value I (0,0),
(2) Strength in the second region surrounded by (φ1, Φ) = (80 °, 0 °), (90 °, 0 °), (80 °, 10 °), (90 °, 10 °) Maximum value I (90,0),
(3) Strength in the third region surrounded by (φ1, Φ) = (0 °, 80 °), (0 °, 90 °), (10 °, 80 °), (10 °, 90 °) Maximum value I (0,90),
(4) Strength in the fourth region surrounded by (φ1, Φ) = (80 °, 80 °), (80 °, 90 °), (90 °, 80 °), (90 °, 90 °) Maximum value I (90,90),
The rolled copper foil whose maximum value Ia is 100 or more among four values represented by these. The surface is subjected to positive electrode spot measurement using an X-ray diffraction method,
The rotation angle about the direction perpendicular to the plane including the [001] orientation of the crystal and the ND direction of the material is Φ, the rotation angle about the ND direction is φ1, and the rotation angle about the [001] direction is When written as φ2,
After rotating by φ1 with the ND axis as the rotation axis, it is rotated by φ to match the ND axis and the z axis, and finally rotated by φ2 around the [001] axis, so that the materials ND, TD, RD And Euler angles (φ1, Φ, φ2), which is a set of angles at which [001], [010], and [100] of the crystal coincide with each other, at φ2 = 0 °,
(1) Intensity within the first region surrounded by (φ1, Φ) = (0 °, 0 °), (10 °, 0 °), (0 °, 10 °), (10 °, 10 °) Maximum value I (0,0),
(2) Strength in the second region surrounded by (φ1, Φ) = (80 °, 0 °), (90 °, 0 °), (80 °, 10 °), (90 °, 10 °) Maximum value I (90,0),
(3) Strength in the third region surrounded by (φ1, Φ) = (0 °, 80 °), (0 °, 90 °), (10 °, 80 °), (10 °, 90 °) Maximum value I (0,90),
(4) Strength in the fourth region surrounded by (φ1, Φ) = (80 °, 80 °), (80 °, 90 °), (90 °, 80 °), (90 °, 90 °) Maximum value I (90,90),
The rolled copper foil whose maximum value Ia is 100 or more among four values represented by these. The maximum value Ia;
The rolled copper according to claim 1 or 2, wherein a ratio Ia / Ib to a maximum intensity value Ib at any measurement point excluding the first region to the fourth region at φ2 = 0 ° is 5 or more. Foil. The rolled copper foil according to any one of claims 1 to 3, wherein the ratio Ia / Ib is 4 or more before final cold rolling and after recrystallization annealing. The degree of final cold rolling is η, and η ≧ 2.3 when expressed as η = ln {(thickness before final cold rolling) / (thickness after final cold rolling)}. Rolled copper foil. The copper clad laminated board which consists of copper foil and resin in any one of Claims 1-5.

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