Interfacial Reactions in the Sn-3.0Ag-0.5Cu/C194 Couples

The solid-liquid interfacial reactions between Sn- 3.0Ag-0.5Cu solder and C194 substrate reacted at 240, 255 and 270°C for 0.5, 1, 2, 4 and 8 h were investigated. Optical microscope, scanning electron microscope, and energy dispersive spectrometer were used to determine intermetallic compounds (IMCs). The results indicated that the Cu
6
Sn
5
and Cu
3
Sn phases with a small Fe solubility were formed at the interface. The IMCs thickness was increased with the increased of the reaction times. The (Cu, Fe)
6
Sn
5
phase was gradually detached from the C194, when the reaction temperature and time was increased.