Assessment of Lead-free Modules Under Forced Mechanical Vibrations by Linear Dynamic Finite Element Methods: Modeling, Result Evaluation and Calibration by Experiments

A commercial finite element code has been applied to simulate industrial standard tall and high-density DRAM modules being exposed to the variable frequency vibration test. Within this framework, the paper introduces to the three linear dynamic simulation methods: modal, harmonic response, and transient analyses. In particular, the models used for describing the geometry, the material behaviour, and the loading conditions are presented. By means of these methods and models, the determination of the natural vibration modes and the mechanical responses of the test vehicle is shown: The seven natural frequencies occurring between 20 Hz and 2000 Hz are found precisely. Mode 1 at 280 Hz leads to the largest displacements. Applying a damping parameter of 0.03, the peak displacement amplitude of 1.8 mm and 1.6 mm is computed for the test point in the middle of the module by harmonic and transient analyses, respectively. They match the corresponding experimental result of 1.7 mm as well as the strain distribution accurately identifies the sites of first failures within the module. This way, linear dynamic simulation reliably allows virtual assessments