CONDUCTIVE MATERIAL FOR CONNECTING PART AND METHOD FOR MANUFACTURING THE CONDUCTIVE MATERIAL

摘要

In a conductive material, on the surface of a base material composed of a Cu plate strip, a Cu-Sn alloy covering layer, which contains a Cu of 20-70at% and has an average thickness of 0.1-3.0µm, and an Sn covering layer having an average thickness of 0.2-5.0µm are formed in this order, and a part of the Cu-Sn alloy covering layer is exposed from the surface of the Sn covering layer at an exposing area rate of 3-75%. Reflow process is performed to the material surface, and preferably, the arithmetic average roughness Ra at least in one direction is 0.15µm or more, the arithmetic average roughness Ra in all the directions is 3.0µm or less, and the average thickness of the Cu-Sn alloy covering layer is 0.2µm or more. The conductive material is manufactured by forming an Ni plating layer, and further, a Cu plating layer and an Sn plating layer as needed on the roughened base material surface, then by performing reflow process.