Submodelling method for modelling and simulation of high-density electronic assemblies

Abstract

In order to enable the computation of fatigue life prediction of high-density electronic assemblies (solder joints > 4000), a modified submodelling approach was developed to integrate the detailed interconnections into equivalent layers with consistent mechanical parameters and thus reduce the complexity of modeling and simulation. The approach incorporates the uniform equivalent interconnect layers into the global model and simulate the general system response to thermo-mechanical loads. Displacements calculated from this first simulation are fed into a local model with more details of worst-case solder joints, in order to obtain local indicator of fatigue life. In this paper, referred to mechanical experimental methodology, a FEA process was used to extract the mechanical parameters of the equivalent layer. The validity of the modified submodelling approach was verified on fatigue life prediction of a high-density flip-chip package under thermal cycling.