This conference paper was submitted for presentation at the NAFEMS World Congress 2025, held in Salzburg, Austria from May 19–22, 2025.

Abstract

This presentation describes an automated simulation process for prediction of chip crack zones, vibrational failure of solder joints and thermal stresses of printed circuit board assemblies (PCBAs). Applied in an early phase of development design loops can be saved as well as physical testing and therefore development costs can be reduced. Every investigation starts with the creation of a finite-element model of the whole PCBA using a suitable discretization. For static and dynamic investigations, the simulation effort can dramatically be reduced by use of a material homogenization approach without a significant loss of accuracy. Specifically, the PCB is coarsely discretized and a separate orthotropic material is generated for each finite element, approximating the complex layer structure of the printed circuit board. This significant reduction in the numerical degrees of freedom to be solved makes such systems accessible for dynamic analyses. Inclusion of all surface mounted devices (SMDs) as well as the solder-joints which are modelled using different sub-structuring techniques complete the method. For the solder joints, the geometry of the solder meniscus is automatically generated using a parametric CAD model and a minimal surface approach, taking into account the surface tension of the liquid solder. The resulting PCBA model is then used to calculate chip crack zones or its dynamic behavior for vibrational damage evaluation of each solder joint. Contrary, thermal investigations require a fine discretized PCBA including all layers, traces and vias of the PCB. With sub-modelling techniques one can assess a detailed thermal stress analysis of critical regions (e.g. plated through holes '“ PTH) in the PCB. In this talk examples for the structural reliability analysis of PCBAs are presented, and how these processes benefit from FEA process automation. Especially the automatic generation of detailed solder joint FE-models as well as detailed FE-models of the PCB based on ECAD-data combined with sub-structuring and material-homogenization techniques reduce the computational effort.