The effect of downscaling the dimensions of solder interconnects on their creep properties

The creep behaviour of solders is an important input for accurate material models for FE-analysis of electronic assemblies. Usually the mechanical behaviour of solders has been determined by tensile tests on bulk solder specimens. Although performing these tests is not complicated and the results are easy to interpret, one of the key problems lies in the fact that solder joints are very small and, therefore, cannot be represented by large tensile specimens. The paper describes the attempts to gain deformation data on ultra small solder joints. It compares creep data that was experimentally gained on bulky samples and on small solder joints.