Recognizing the growing need for higher power capability device interconnects, high-end device manufacturers are exploring the possibility of all copper interconnects. Electromigration-resistant copper interconnects can be made using a flip chip dipping process with a copper sintering paste. Subsequent copper sintering to the carrier pad requires a carefully controlled reducing atmosphere. Preparing for member-driven evaluations of such copper sintering systems, the APL has constructed an experimental apparatus for the sintering of copper in a formic acid environment. It will be used for studies of copper sintering kinetics and interfacial bond integrity as a function of time, temperature and pressure.
Sintering Copper Interconnects in Formic Acid
