Conductive material for connecting part and method for manufacturing the conductive material

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 direct-on, 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.

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 an Sn plating layer 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.

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 0.3 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.

A method for fabricating a conductive material, the method comprising:

• preparing a base material made up of a Cu strip;
• rendering an arithmetic mean roughness Ra of a surface of the base material in at least one direction, not less than 0.3 μm, and the arithmetic mean roughness Ra of the surface, in all directions, not more than 4.0 μm;
• forming an Sn plating layer 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.