Correlation Between Sn Grain Orientation and Corrosion in Sn-Ag-Cu Solder Interconnects
Source: Journal of Electronic Materials, Volume 40, Number 9, September 2011 , pp. 1895-1902(8)
Abstract:The impact of a marine environment on Sn-Ag-Cu interconnect reliability is examined using salt spray exposure followed by thermal cycling. Sn-Ag-Cu solder alloy wafer-level packages, with and without pretreatment with 5% NaCl salt spray, were thermally cycled to failure. The prior salt spray reduced the characteristic lifetime of the Sn-Ag-Cu solder joints by over 43%. Although Sn-based materials show strong resistance to corrosion, the nature of localized corroded areas at critical locations in the solder joint caused significant degradation in the Sn-Ag-Cu solder joints. An important link between the corrosion path and Sn grain orientation was observed using orientation imaging microscopy (OIM). A strong correlation between the corrosion path and grain orientation was identified, indicating that the corrosion attack preferentially followed the basal plane of the Sn lattice.
Document Type: Research Article
Affiliations: 1: Component Quality and Technology Group, Cisco Systems, Inc., San Jose, CA, 95134, USA, Email: firstname.lastname@example.org 2: Component Quality and Technology Group, Cisco Systems, Inc., San Jose, CA, 95134, USA 3: Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI, 48824-1226, USA
Publication date: September 2011