Chromatographic studies to evaluate circuit board cleanliness

Chromatography, in its various forms, is shown to be a useful analytical technique for the characterization of contaminants on circuit boards and components. Three different forms of chromatography are described: high performance liquid chromatography (HPLC), ion chromatography (IC), and gas chromatography/mass spectrometry (GC/MS). Each of these techniques is optimized for the analysis of different contamination problems. The use of HPLC in determining residual rosin on circuit boards is described, as well as the use of IC for monitoring the cleanliness of film integrated circuits (FICs) during various steps of manufacture, including cleaning stages. A final example involves the use of GC/MS for the analysis of contaminants within sealed relays. The choice of which chromatographic technique to use is dictated by the goals of the analysis and the nature of the contamination