Finite element model updating of board-level electronic packages by factorial analysis and modal measurements

Abstract

PurposeOne difficultly in building an effective finite element (FE) model of a board-level package is because of complex structure of the printed circuit board (PCB), as it contains copper layers, woven fabrics, plated-through holes and so forth. Therefore, it is often acceptable to obtain equivalent orthotropic material properties and use them in the simulation. This paper aims to provide a research methodology to produce equivalent FE models for board-level electronic packages.Design/methodology/approachIn this methodology, the FE models’ data were correlated with experimental modal analysis results in terms of natural frequencies and mode shapes. Statistical factorial analysis was used to examine the electronic assembly material properties effect on the structure’s resonant frequencies. The equivalent material properties of the PCB were adjusted using the optimization tool available in ANSYS software for free boundary conditions. The equivalent FE model was then validated for the fixed boundary conditions.FindingsThe resultant FE models were in great match with the measured data in terms of resonant frequencies and mode shapes. The so-developed models can be further used in the analysis of the dynamic response of the electronic packages and solder interconnects.Originality/valueThe current approach provides a sophisticated research methodology to provide high-accuracy FE models of electronic assemblies subjected to vibration. The main value of this approach is to first test the effect of each material property on the package dynamic characteristics before starting the correlation process, then to automate the correlation algorithm using the built-in FE model updating feature available in ANSYS software.