A PTH Barrel Stress Distribution Model and Associated PWB Design Factors

The IPC methodology as an industry standard for plated through hole (PTH) reliability assessment considers the uniform thermal stress condition of PTH barrels, which noticeably deviates from the actual conditions. This makes it difficult for engineers to use the methodology and effectively explore printed wiring board (PWB) design rules. To provide an alternative, Xie proposed an enhanced thermal stress model and demonstrated preliminarily its effectiveness in PTH reliability assessment. This paper, in addition to a brief review of the enhanced model, presents a follow-on study to comprehensively verify the model by comparing the model results with those of finite element method. This paper also provides a discussion on associated PWB design factors and their effect on PTH barrel stress distributions as well as fatigue life.