Polymeric conductive pastes as solder replacement for flip-chip attachment

The fabrication and characterization of flip-chip assemblies using four polymeric conductive pastes as attachment materials are reported. Three thermoset and one thermoplastic polymeric conductive pastes were investigated. Polymeric conductive pastes having silver particles 2 μm in size made good contact to either smooth or rough metal. Electrical contact with pastes whose particles were 5 μm or larger could only be obtained on rough metal.