Electrochemical Methods to Measure the Corrosion Potential of Flux Residues

Reliability Expectations of Highly Dense Electronic Assemblies is commonly validated using Ion Chromatography and Surface Insulation Resistance. Surface Insulation Resistance tests resistance drops on both cleaned and non-cleaned circuit assemblies. It is well documented in the literature that SIR detects ionic residue and the potential of this residue to cause leakage currents in the presence of humidity and bias. Residues under leadless components are hard to inspect for and to ensure flux residue is totally removed. The question many assemblers consider is the risk of residues that may still be present under the body of components....