Mechanical properties of soft solder materials for electronic applications

The reliability of electronic components depends directly on the long time stability of the materials used for component construction, e. g. the soft solder materials. The characterization of mechanical properties of soft solder materials is very complicated due to different factors influencing the proper ties of the soldered connections, i. e. - Formation of brittle intermetallic phases in the interconnecting zone. - Different wetting behavior of identical materials on different substrates. - Influence of the ambient soldering atmosphere on the materials properties, i. e. corrosion behavior. In the present paper results of different mechanical tests for typical Pb-base and Sn-base solder alloys are presented. Mechanical properties after long time annealing, thermal shock, thermocycling experiments are shown. Influence of the individual microstructures of the mechanical properties of the soft sol ders is discussed. The individual wetting behavior of the soft solder materials on substrates is demonstrated.