Degradation of Cu6Sn5 intermetallic compound by pore formation in solid-liquid interdiffusion Cu/Sn microbump interconnects

- A degradation phenomenon of the Cu6Sn5 IMC in SLID interconnects was found.
- Degradation is caused by porosity due to a corrosive reaction with flux residues.
- Sn is dissolved from the solid Cu6Sn5 IMC during the pore formation.
- The composition of the remaining phase in the pore region is close to Cu3Sn.
- The complete transformation into non-porous Cu3Sn is possible after the removal of the flux residues.