X-Ray Fluorescence (XRF)
XRF analysis determines the elemental composition of the leads/package of a component and is a useful test for Lead Finish Evaluation to determine lot consistency and confirm the presence or absence of lead (Pb) or other constituent elements. While the initial method of detecting re-plated leads is the External Visual Inspection, Lead Finish Evaluation using XRF, augments the findings of External Visual Inspection. During the External Visual Inspection, leads are inspected for any finish abnormalities including color variations, lack of exposed base metal at the lead tip, damaged leads, plating thickness variations, scratches and/or insertion marks, oxidation, corrosion, presence of solder and/or flux, etc.
The subset of parts selected for the Lead Finish Evaluation, are specifically chosen based on the visual inspection results and the sublots created based on that inspection and include a representative sample from each variation observed during detailed External Visual Inspection.
AAA recommends a minimum of 3 samples be subjected to XRF testing.