Mechanical Shock FE Modeling for ATCA Circuit Board Design

Abstract

ATCA is a new form factor for communication equipment applications. Finite element model (FEM) was created to predict the dynamic response of an ATCA design during a table drop shock. The model was built with 2nd order brick elements for minimizing the meshing sensitivity. Modal method was used and followed by dynamic transient analysis with superposition approach and validated by comparing the modal test data for matching the natural frequencies and the modal shapes. The model was further validated by comparing the board displacement with direct displacement measurement using a high speed camera. As a result the localized board strain predictions matched the measured board strain at each networking processor unit. The validated model was used to predict the risk areas for solder joints, which later proved to be accurate during board design verification tests. This paper presents the modeling and model validation processes, as well as the ATCA mechanical design evaluations.