BONDING MEMBER

摘要

Provided is a bonding member that has excellent solder bonding properties and is free of problems including a problem of misalignment of a bond part even after reflow, particularly after second reflow. The bonding member according to the present invention is provided with a plating film mainly composed of a Cu-Ni alloy. In the plating film, the Cu mass ratio represented by the formula Cu/(Cu+Ni) is increased and decreased within the range from 0.7 to 0.97 when observed in the film thickness direction. In addition, the order of the increase and the decrease in the Cu mass ratio is greater than 0.1. Therefore, when the plating film mainly composed of a Cu-Ni alloy is subjected to the solder bonding to a Sn-based solder material or the like, an intermetallic compound layer having a high melting point can be formed in the bond part. Further, since the plating film has a layer having a slow reaction rate, it becomes possible to reduce the reaction rate of the alloying reaction between a Cu-Ni alloy and a Sn-based metal.