文档介绍：Finite Element Stress Evaluation Of posite Board
using 2-D and 3-D Convection Models
Amir Khalilollahii
Pennsylvania State University, The Behrend College

Abstract
Thermal fatigue and high levels of thermal stresses in electronic circuit boards have been of great concerns to
designers in a wide range of applications such as avionics puters. Fluid/thermal/structural models
were integrated in this study to enable the predictions of the temperature and stress distribution of vertically
clamped parallel circuit boards that include series of symmetrically mounted heated electronic modules
(chips). The board was modeled as a thin plate containing heated flush rectangular areas representing the heat
generating modules. Initially two convection models, a 2-D and a 3-D model were incorporated to predict the
heat transfer coefficients that strongly affect the temperature distribution in the board and chips. Then ANSYS
models were used to incorporate the effects of mixed convection on surfaces, heat generation in the modules,
and conduction inside the board. Then analyses were performed by ANSYS using structural elements capable
of handling orthotropic material properties. The stress fields were obtained pared for the two models
possessing different convection models.
Introduction
Thermal analysis of circuit boards is of much interest mainly becaus