Patent ID: 8445057

Claim:
A method for fabricating a conductive material, the method comprising: preparing a base material made up of a Cu strip; causing a surface of the base material to have surface roughness so that an arithmetic mean roughness Ra, in at least one direction, is not less than 0.15 μm, and the arithmetic mean roughness Ra, in all directions, is not more than 4.0 μm; forming a Cu plating layer, and an Sn plating layer in that order, over the surface of the base material; and applying a reflow process thereto, thereby forming a Cu—Sn alloy covering layer, and an Sn covering layer in that order from the surface of the base material; wherein a ratio of an exposed area of the Cu—Sn alloy covering layer to a surface of the conductive material is in a range of 3-75%.