The development of lead-free solder materials with improved reliability properties requires a detailed understanding of the relationship between mechanical properties and microstructure. The paper presents methods that can be applied to characterize creep and plastic deformation behaviour and shows how currently available analytical methods for microstructure investigations can be used to track the physical origin of the observed mechanical behaviour. The paper will specifically describe advantages and use of mechanical and analytical tools, like nanoindentation, FIB, SEM, TEM and EDX in the field of solders for interconnects in electronic packaging.