Retarding growth of Ni3P crystalline layer in Ni(P) substrate by reacting with Cu-bearing Sn(Cu) solders was analyzed. The 5 μm Ni(P) was found to be consumed after 5 min of reflowing. The spalling of Ni-Sn compound grains enhanced the formation of a gap forming at the Ni3O/Cu interface.
- Pb-free solder
- Sn(Cu) alloys