Reliability Issues in Plated-Through-Holes Due to Insertion-Mount Compliant-Pin Connectors

Abstract

Stresses arising in plated through holes (PTHs) and surrounding printed wiring board (PWB) substrates due to pin forces of insertion-mount compliant-pin connectors are modeled analytically. The analytical model is based on separation of variable techniques using Fourier series representation of the pin loads, and will be calibrated in the future using both experimental measurements as well as numerical finite element results. Linear and nonlinear results are presented in this paper, to predict deformation and stresses in the assembly. Incremental load-stepping methods are used, to handle nonlinear material properties such as elastic-plastic behavior of copper and post-damage behavior of the PWB substrate. The nonlinearity of the materials is modeled with a simplified bilinear stress-strain curve. The goal is to develop mechanistic predictive models for PTH behavior under insertion forces of compliant pins, to reduce the need for highly repetitive and costly failure analysis for damage evaluation, resulting in significant cost savings to the industry as a whole.