2015 Volume 8 Issue 1 Pages 1-7
Nickel/gold electroless plating is commonly used for surface finishing of printed wiring board due to its environmental stability and good solder wettability. However, since the gold deposition of electroless gold plating is a substitution reaction, local corrosion of nickel surfaces sometimes occurs which decreases the joining reliability of solders or wire bonding.
In this study, we focused on the internal stress of the nickel-plating layer. Gold electroless plating was performed on nickel plating with different internal stress levels, and the local corrosion behavior and shear strength of solder balls were investigated. Our results clearly show that the tensile strength of the nickel layer increases the occurrence of local corrosion and accordingly results in the deterioration of the solder joining strength.