Patent ID: 8293039

Claim:
A method of manufacturing a sheet of a copper-based alloy, containing Ni: 0.01-4.0 wt. %, Sn: 0.01-10 wt. %, and P: 0.01-20 wt. %, optional containing 0.03-3.0 wt. % of Zn or 0.01-3.0 wt. % of at least one element selected from the group consisting of Fe, Co, Mg, Ti, Cr, Zr, and Al with the remainder being Cu and unavoidable impurities, where the x-ray diffraction intensity ratio of the surface S ND is such that 0.05≦S ND ≦0.15, provided that S ND =I{200}÷[I{111}+I{220}+I{311}], where I{200} is the x-ray diffraction intensity of the {100} plane, I{111} is the x-ray diffraction intensity of the {111} plane, I{220} is the x-ray diffraction intensity of the {110} plane, and I{311} is the x-ray diffraction intensity of the {311} plane, comprising the steps of: taking an ingot of a copper-based alloy having the indicated elemental composition, performing a combination process of cold rolling followed by annealing at least one time, thereafter performing intermediate cold rolling, which is a cold rolling process before a final cold rolling process, thereby making the x-ray diffraction intensity ratio of the sheet surface S ND such that 0.05≦S ND ≦0.15, performing annealing with controlling a temperature and time to obtain sheet with a grain size of 20 μm or less, and performing the final cold rolling at a percent reduction Z that satisfies the following Formula: 0.8×(100−10 X−Y )< Z< 100−10 X−Y where Z is the percent cold reduction (%), X is the Sn content (wt. %) among the various elements, and Y is the total content (wt. %) of all elements other than Sn and Cu, followed by low-temperature annealing performed at a temperature below the recrystallization temperature.