Characterization methods for determination of temperature depended electrical, thermal, mechanical and fatigue properties of SnAg3.5 solder

The application of solder joints for electrical and mechanical interconnections between two functional layers in electronic packages will be present in future devices, even in 3D-electronic devices. Very different approaches are investigated such as copper pillar, full inter-metallic joints or Au-Sn nanosponge. But the interconnection realization by μ-solder bumps as well as Flip-Chip solder joints will be one high potential connection method. The fundamentals about the solder alloy properties are necessary for material selection at product planning phase and further for the reliability estimations. Modern simulation tools are used for weak point estimations as well as for lifetime estimations (e.g. FEM). Any simulation software demands martial properties. The paper presents an excerpt of characterization techniques and results for the following physical data of SnAg3.5 solder: (1) Elastic modulus (2) Poisson ratio (3) Creep (4) Lin. thermal expansion (CTE) (5) Thermal conductivity (6) Electrical conductivity (7) Fatigue.