1. Microstructure, Defects, and Reliability of Mixed Pb-Free/Sn-Pb Assemblies
- Author
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Simin Bagheri, Marianne Romansky, Craig Hamilton, Heather McCormick, Polina Snugovsky, and Zohreh Bagheri
- Subjects
Materials science ,Rework ,Temperature cycling ,Condensed Matter Physics ,Microstructure ,Electronic, Optical and Magnetic Materials ,Soldering ,Ball grid array ,Void (composites) ,Materials Chemistry ,Electrical and Electronic Engineering ,Composite material ,Failure mode and effects analysis ,Eutectic system - Abstract
The results of an intensive reliability study on Pb-free ball grid array (BGA)/Sn-Pb solder assemblies as well as some lessons learnt dealing with mixed assembly production at Celestica are described in this paper. In the reliability study, four types of Pb-free ball grid array components were assembled on test vehicles using the Sn-Pb eutectic solder and typical Sn-Pb reflow profiles with 205°C to 220°C peak temperatures. Accelerated thermal cycling (ATC) was conducted at 0°C to 100°C. The influence of the microstructure on Weibull plot parameters and the failure mode will be shown. Interconnect defects such as nonuniform phase distribution, low-melting structure accumulation, and void formation are discussed. Recommendations on mixed assembly and rework parameters are given.
- Published
- 2008
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