Development and Application of Composite Material Lamination Theory for Printed Circuit Boards

Abstract

Layers incorporating carbon fiber materials have been proposed to enhance the reliability of high performance printed circuit board production configurations. The carbon fiber layers feature high stiffness and high thermal conductivity, as well as near zero thermal expansion coefficients. In this research, theoretical approaches based on lamination theory have been developed for estimating the global/bulk coefficients of thermal expansion and mechanical properties of printed circuit boards incorporating carbon fiber layers based on the layer properties and stack-up configuration. Different types of carbon fiber laminates have been studied and tested. The coefficients of thermal expansion of individual carbon fiber PCB layers (plies) have been measured using strain gages with a temperature controlled chamber. The elastic moduli, Poisson’s Ratios, and shear modulus of individual carbon fiber plies have also been evaluated. An indirect method was developed and applied to find the shear modulus and Poisson’s ratio. The approach was applied to some example PCB configurations, and compared to the results of finite element analyses.