Cu-In-Microbumps for Low-Temperature Bonding of Fine-Pitch-Interconnects

The advancing heterogeneous integration of various electronic components into a single package requires in particular further development of bonding technologies towards lower temperatures. In our present study, we show the successful joining of dies consisting of Cu-microbumps with In solder caps. Stable interconnections were achieved at a bonding temperature of 180 °C in 2 min by solid-liquid-interdiffusion (SLID).