The "Smeared" Property Technique for the FE Vibration Analysis of Printed Circuit Cards

Abstract

The primary objective of this paper is to investigate the accuracy of the finite element (FE) smeared properties approach for the determination of the mode shapes and frequencies of a printed wiring board (PWB) populated with electronic modules. Smearing of the material and/or structural properties is a recognized means of reducing a complicated structure to a less complicated approximation. Comparisons of both the natural frequencies and mode shapes are made between the smeared FE model and those obtained from vibration testing. The extent of correlation between the mode shapes is characterized by the modal assurance criterion (MAC). Since the intent of this study is to examine the effectiveness of the smearing technique, free boundary conditions are assumed. It is shown that the smearing technique can produce good correlation of both natural frequencies and mode shapes of PWBs populated with modules. A case study of a PWB with both surface mount technology (SMT) and pin-in-hole (PIH) components is presented.

Fatigue Life Prediction for PBGA under Random Vibration Using Updated Finite Element Models

“…Lead spring constants can be used in place of detailed lead models when only the PCB response is required [5,6]. Further simplification can be made by including the effect of the component with artificially increased stiffness and density of the underlying PCB properties in the FE model or with simple block 3D elements [7][8][9][10]. Using experimental data, Lim et al and Barker et al give examples of how the edge rotational stiffness can be calculated for use in a PCB FE model [11,12].…”

Reliability Assessment of Microelectronics Packages Using Dynamic Testing Methods

“…The PBGA assembly is a very complex structure, as each PBGA module has 256 solder joints. In order to overcome this difficulty, different modeling techniques, including structural dynamic modification, submodeling, and the "smeared" property technique, were developed to evaluate the dynamic properties of PCB assemblies [19][20][21]. However, a detailed stress analysis of solder joints is not available now and is still under development.…”

Modelling and Simulation of Effect of Component Stiffness on Dynamic Behaviour of Printed Circuit Board

“…Pitarresi [3], Pitarresi, et al [4], and Pitarresi and Primavera [5] provided the solutions for issues encountered in modelling the PCB assembly that includes a wide variety of components. In this paper, modelling and simulation of a typical component mounted on PCB used for space applications is carried out.…”