Comparison of Modeling Techniques for the Vibration Analysis of Printed Circuit Cards

Abstract

The estimation of the mechanical reliability of components on a vibrating circuit card continues to be an important part of the overall reliability assessment for electronic packages. To achieve a good vibration reliability estimate it is necessary to have an accurate representation of the dynamic response of the card. This can be realized by having the modal characteristics of the circuit card, i.e., its natural frequencies and mode shapes, accurately modeled. It is the primary objective of this paper to review some of the current modeling techniques for the dynamic characterization of circuit cards populated with components. Performance assessments include tangible factors such as accuracy of predicted frequencies and mode shapes, as well as less tangible factors such as ease of use. The circuit cards considered in this study are intended to be representative of small to medium sized logic, memory, and processor cards used in commercial electronics; the card is composed of laminated copper and FR-4 glass epoxy, typically without a bonded heat sink or intermediate stiffeners, and it may be populated with both SMT and PIH components.