REACTION OF NANOCRYSTALLINE CU-SN ALLOY WITH GA-IN-SN EUTECTIC

An extended solid solution of Cu-20%wtSn with a lattice parameter of 0 .3715 nm and a crystalline grain sizes D ranging from 30-7 nm was obta ined by mechanical alloying. The reaction rate for the formation of Cu Ga2 due to the interaction of Cu-20%wtSn with a Ga-In-Sn liquid at roo m temperature increased significantly when D decreased to 7 nm. A mech anical alloying process was used to control the reactivity of the nano crystalline solid solutions, used as components in the low temperature solder pastes.