Finite element modeling (FEM) has been used for thermal, mechanical, thermo-mechanical and even coupled electro-thermal-mechanical analysis. The applications of FEM are in the field of IC-packaging, MEMS (micro-electromechanical system) and CMOS reliability.
The estimation of solder joint reliability for IC packaging is now focusing to lead-free materials as the European legislation deadline is coming very close (by July 2006, all Pb must be banned in electronic systems, except for a few applications) (RP46). A first empirical model is derived for estimation of lifetime of SnAgCu solder joints by FEM. The modeling work is also assisted by experiments such as creep behavior, CTE, elastic modulus, brittleness transition temperature and thermal cycling testing for several lead-free alternatives (Sn, SnAg, SnAgCu, SnCu and SnCuNi) (Figure1)
Figure1: Comparison of –40 |