Nickel/palladium finish for leadframes

The structure (and its rationale) of the palladium/nickel leadframe finish which Texas Instruments introduced in 1989 is reviewed and the reasons for its development, the advantages and features of this lead finish are discussed. Unique implications for the leadframe maker, the assembly test site and for the end user, result from using this finish, some of which were not anticipated at its inception. There are now more than 30 billion devices in the field with palladium/nickel plated leads. A synopsis of the performance of this finish with one of the lead-free pastes in the market is included. There is also a section on the observed shelf life of this finish under Battelle class 2 mixed flowing gas conditions.