Creep Rupture of Lead-Free Sn-3.5Ag-Cu Solders
Authors: Joo, D.K.; Yu, Jin; Shin, S.W.
Source: Journal of Electronic Materials, Volume 32, Number 6, 1 June 2003 , pp. 541-547(7)
Abstract:Creep-rupture properties of lead-free Sn-3.5Ag-based alloys with varying amount of Cu were investigated using rolled and heat-treated dog-bone-shaped specimens. Nominal compositions of added copper were 0 wt.%, 0.5 wt.%, 0.75 wt.%, 1.0 wt.%, and 1.5 wt.%. During creep tests, the matrix hardness dropped significantly, and the minimum strain rates (min) were lowest for the 0.75Cu specimens. The stress exponents (n) of min were usually around 4, with the exception of the 0.5Cu and 0.75Cu alloys, which showed somewhat higher values of n. Fractographic analyses revealed typical creep rupture by the nucleation and growth of cavities in the matrix except the 1.5Cu specimens, which showed cavity nucleation at brittle Cu6Sn5 particles.
Document Type: Miscellaneous
Publication date: June 1, 2003