Cu-co-si-fe-p-based alloy with excellent bending formability and production method thereof

A method for producing a copper alloy for an electronic material comprising:

• (a) melting and casting 1.2 to 2.5% by mass of cobalt (Co), 0.2 to 1.0% by mass of silicon (Si), 0.01 to 0.5% by mass of iron (Fe), 0.001 to 0.2% by mass of phosphorus (P), a balance amount of copper (Cu), and optionally, 0.05% by mass or smaller of each of at least one selected from a group consisting of nickel (Ni), manganese (Mn) and magnesium (Mg), thereby to obtain an ingot;
• (b) maintaining the ingot at 900 to 1100° C. for 30 minutes to 4 hours and then hot rolling the ingot to form a product;
• (c) performing a first cold rolling treatment of the product at a cold reduction rate of 90% or greater to form a sheet material;
• (d) performing an intermediate heat treatment of the sheet material at 400 to 800° C. for 5 to 500 seconds;
• (e) preforming a second cold rolling treatment of the sheet material at a cold reduction rate of 70% or smaller;
• (f) performing a solution treatment of the sheet material at 900 to 1100° C. for 5 to 500 seconds;
• (g) performing a third cold rolling treatment of the sheet material at a cold reduction rate of 10% or greater;
• (h) performing two-stages precipitation including:
• a first stage precipitation in which the sheet material is heated at 480 to 600° C. for 1 to 24 hours, and a second stage precipitation in which the sheet material is heated at 400 to 550° C. for 1 to 24 hours;
• (i) performing a final cold rolling treatment of the sheet material at a cold reduction rate of 5 to 70%;
• and
• (j) performing a stress removal treatment of the sheet material for 2 to 3000 seconds at 300 to 700° C.