Patent ID: 9457389
Filing Date: 2016-10-04
CPC Classification: B21B,C22C,C22F,H05K,Y10T

Claim Text:
1. A rolled copper foil comprising crystal particles of copper or a copper alloy, the rolled copper foil comprising: an average particle size of the crystal particles composing the outermost surface of the rolled copper foil of not less than 0.2 μm and not greater than 6 μm; a ratio of the average particle size of the crystal particles composing the outermost surface of the rolled copper foil to a thickness of the rolled copper foil of not less than 1% and not greater than 6%; and an intragranular distortion rate, found by the following formula (1) when a cross-section perpendicular to a length direction of the rolled copper foil is analyzed by electron backscatter diffraction (EBSD), of not less than 0.5% and not greater than 10%: in the formula (1), (A) represents an area of a region identified through image analysis to have an orientation difference of not less than 1 degree and not greater than 15 degrees, and (B) represents an area of a region identified through image analysis to have an orientation difference of not less than 0 degrees and not greater than 15 degrees, wherein the rolled copper foil is formed by rolling a round wire copper material into a foil shape, and the rolled copper foil is formed by performing a heat treatment on the round wire copper material in the foil shape under conditions from 300° C. to 500° C. and from 0.01 seconds to 100 seconds.