Failure Analysis - Using Ion Chromatography and Ion Chromatography/Mass Spec (IC/MS)

Abstract

Since the 1980s the electronics industry has utilized ion chromatography (IC) analysis to understand the relationship of ions, and some organics, to product reliability. From component and board fabrication to complete electronic assemblies and their end-use environment, IC analysis has been the de facto method for evaluating ionic cleanliness of electronic hardware. Typical ions accounted for include chloride, bromide, nitrate, sulfate, weak-organic acid (WOA), sodium and ammonium. Environmental and other concerns have driven the industry to adopt myriad flux formulations, which has created a need to further differentiate weak-organic acids beyond what a typical IC system using conductivity can provide. By utilizing an Ion Chromatography/Mass Spectroscopy (IC/MS) system optimized for organic separation, we can use the same IC column technology for the typical suite of anion/organic species, then run the sample through a quad-pole mass spectrometer which provides the molecular weight assessment of organics for over two dozen channels. This capability is critical to our failure analysis work at Foresite, as it allows for identification of specific organic acids and flux activators. This information can aid in identifying specific residue sources (e.g. board fabrication, SMT paste flux, waver solder liquid flux, hand solder flux or a completely different, possibly unauthorized, source.