Cu3Sn suppression criterion for solid copper/molten tin reaction
Résumé
The formation of Cu3Sn phase in the soldering reaction is believed to be harmful for the reliability of solder contacts on account of Kirkendall voiding in the compound. In this study, a criterion for the suppression of the growth of this phase by the fast growing scallop-like Cu6Sn5 compound is presented. The average thickness of the η-Cu6Sn5 phase above which the ε-Cu3Sn phase starts to grow as a continuous layer at the Cu/Cu6Sn5 interface during liquid Sn/solid Cu interaction has been evaluated from thermodynamic and kinetic considerations.