Palladium as a lead finish for surface mount integrated circuit packages

The authors discuss the use of a thin, preplated palladium lead finish as an alternative to solder. Tests and experiments designed to examine several key properties and behaviors of Pd as related to this application were performed. These tests included: wetting characteristics, solder joint metallurgy, wire bonding, interaction with molding compounds, and electrochemical characteristics. Following initial feasibility studies, an extensive set of reliability and performance tests were run on a wide range of packaged integrated circuits. These included: operating life, temperature/humidity, thermal cycle/shock, lead finish performance and visual/mechanical tests.<
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