Detection of Corrosion in Thick Film Resistors by X-Ray Imaging

Abstract

In this article, a non-destructive method, using 2D X-ray imaging, to investigate corrosion defects in thick film resistors stressed by two different corrosion experiments, the single gas experiment and the flowers of sulphur experiment, is presented. In total, 370 devices under test (DUTs) were investigated, using the 2D X-ray imaging technique, of which 10 were imaged in a sequence of 2D X-ray images to evaluate the corrosion propagation. The observed underlying corrosion product was verified by using focused ion beam analysis combined with an energy dispersive X-ray spectroscopy. The presented 2D Xray imaging technique enables a fast and non-destructive method for accurately identifying corrosion and corrosion progression in thick film resistors. The presented imaging method was found to be especially suitable for supplier benchmarking purposes as well as for failure analysis of field returns as it allows for proper corrosion evaluation of surface mount thick film resistors while keeping the analyzed assembly intact.