Abstract
Ni plating is widely used as the metallization for solder joints in semiconductor devices. However, reliability degradation occurs in the joint interface, because numerous voids are formed during soldering, which leads to heat loss at the solder joints.This paper describes the void formation mechanism and the reaction mechanism between Ni plating and solder. The defective area of an oxide film on plated Ni film can be broken by Sn and H2 before the Ni surface is cleaned. Sn reacts with Ni, resulting in the formation of intermetallic compounds. Voids form in the areas where oxide film is remains. When joining plated Ni film and solder, it is necessary to remove the oxide film from the Ni surface in order to decrease the number of voids.
