Rolled copper foil and manufacturing method thereof
View Patent ↗A rolled copper foil applied with a recrystallization annealing after a final cold rolling step and having a crystal grain alignment satisfying a ratio of [a]/[b]≧3, where [a] and [b] are normalized average intensities of a {111} Cu plane diffraction of a copper crystal by β-scanning at α=35° and 74°, respectively, in an X-ray diffraction pole figure measurement to a rolled surface is manufactured by controlling a total working ratio in the final cold rolling step before the recrystallization annealing to be 94% or more; and controlling a working ratio per one pass in the final cold rolling step to be 15 to 50%.
1. A rolled copper foil made of a tough pitch copper or an oxygen-free copper, and obtained after a final cold rolling step but before a recrystallization annealing, and having a crystal grain alignment wherein, in results obtained by an X-ray diffraction pole figure measurement with respect to a rolled surface of the rolled copper foil, the crystal grain alignment indicates that a normalized average intensity of a {111} Cu plane diffraction of copper crystal, which is obtained by β-scanning in a range of α angle of 35° to 75° is not a stepwise form, or has substantially only one maximal region.
2. The rolled copper foil according to claim 1 , wherein:
in results obtained by an X-ray diffraction 2θ/θ measurement with respect to the rolled surface, 80% or more of diffraction peaks of the copper crystal occurs on a {220} Cu plane.
3. The rolled copper foil according to claim 1 , wherein: the rolled copper foil is made of a copper alloy comprising 0.001 to 0.009 mass % of Sn and a balance being Cu and an inevitable impurity.
4. The rolled copper foil according to claim 3 , wherein the rolled copper foil is made by a method, comprising:
preparing an ingot made of the copper alloy;
conducting a hot rolling step;
conducting a plurality of times a step comprising the substeps of conducting a cold rolling step and then a process annealing step; and
conducting a final cold rolling step to produce the rolled copper foil of a predetermined thickness;
wherein a total working ratio in the final cold rolling step before a recrystallization annealing is 94% or more; and
a working ratio per one pass in a final cold rolling step is 15 to 50%.
5. The rolled copper foil according to claim 4 , wherein:
a working ratio of one pass in the final cold rolling step is “working ratio at first pass”≧“working ratio at second pass”≧“working ratio at third pass”; and
a working ratio at third or more passes in a final cold rolling step is 15 to 25%.
6. The rolled copper foil according to claim 1 , wherein the rolled copper foil is made by a method, comprising:
preparing an ingot made of the tough pitch copper or the oxygen-free copper;
conducting a hot rolling step;
conducting a plurality of times a step comprising the substeps of conducting a cold rolling step and then a process annealing step; and
conducting a final cold rolling step to produce the rolled copper foil of a predetermined thickness;
wherein a total working ratio in the final cold rolling step before a recrystallization annealing is 94% or more; and
a working ratio per one pass in a final cold rolling step is 15 to 50%.
7. The rolled copper foil according to claim 6 , wherein:
a working ratio of one pass in the final cold rolling step is “working ratio at first pass”≧“working ratio at second pass”≧“working ratio at third pass”; and
a working ratio at third or more passes in a final cold rolling step is 15 to 25%.
8. The rolled copper foil according to claim 1 , wherein:
in results obtained by an X-ray diffraction 2θ/θ measurement with respect to the rolled surface, occupation ratio of a {200} cu plane of the copper crystal is 80% or more.
9. The rolled copper foil according to claim 1 , wherein the rolled copper foil is made of an oxygen free copper.
10. The rolled copper foil according to claim 1 , wherein the rolled copper foil is made of tough pitch copper.