The purpose of this paper is to evaluate modeling of the reliability characteristics of the copper (Cu) used in plated through holes (PTHs) for electrical connections across printed circuit boards (PCBs).
Assessments of the Cu damage in the first three reflow cycles are performed using finite element analysis. A two‐dimensional axi‐symmetric model of a PTH on a laminate board is validated against a three‐dimensional full model and test cases. Stress and strain measurements in the inner ring of the PTH are obtained in numerical simulations.
Loads applied after the reflow cycles contribute to subsequent mechanical disconnects. Reliability assessments relying on undamaged circuits are less accurate than estimates incorporating Cu damage following three reflow cycles.
In order to increase the accuracy of PCB reliability predictions significantly, prior‐to‐use damage should be calculated. In this paper, a modification to the reliability analysis is proposed.
