Migration Characteristics of Contact Materials Insulation Reliability of Connectors with Palladium Plated Contacts

摘要

palladium has been put into practical use as a contact plating material for connectors due to its excellent insertion/extraction durability, soldering characteristics and its cost effectiveness when compared with gold. Palladium, Luke gold and nickel, has been regarded as a metal that hardly migrates. Today, however, as the electronic components are mounted at higher densities and smaller pitches, some complaints of palladium migration have been reported, challenging the established theory. We investigated the migration characteristics of palladium with a simple acceleration test using filter paper in hopes of helping to assure the quality of connectors with palladium-plated contacts. It was confirmed that palladium migrates in a short time period under very humid atmospheric conditions and at a comparatively low potential gradient. It was also confirmed that the presence of Cl ions is the crucial condition for palladium migration to occur.