Thermoplastic Finite Element Analysis of Unfilled Plated-Through Holes During Wave Soldering

Abstract

Previous related research has not developed a consensus on the issue of how stress analyses of plated-through hole (PTH)/printed wiring board (PWB) structure subject to uniform temperature change can approximate the fully transient case. In this study, these two types of analyses are conducted using McDowell’s thermoplastic model with previously developed numerical implementation by applying a finite element package and an associated user-defined material subroutine. The same wave soldering temperature profile is used. The detailed stress/strain responses of the copper layer, along the heating and cooling of the wave soldering process, are compared at both the PTH corner and barrel portions. The temperature distributions and corresponding deformations of the model are also reported for the fully transient thermal and one-way coupled mechanical analysis. It is concluded that despite the transient thermal loading, the residual stress and strain distributions within the PTH/PWB structure after cooling can be adequately approximated using the more simple analysis which prescribes a uniform temperature and temperature change at each stage of the process.