Various forms of contamination on the surface of hydrocarbon ceramic dielectric PWBs have been observed following component population. Although contamination is occasionally observed on PWBs fabricated from other dielectric materials, the light color of hydrocarbon ceramic substrates increases the frequency of detection, and consequently increases the number of investigations into possible contamination causes and impacts to reliability. Three contamination types are evaluated: staining due to rework of gold plated surfaces, discoloration due to flux application, and the resulting anomalies due to the effects of multiple chemical processing steps. The causes of the anomalies, quantitative analysis of residues, and impacts to reliability for each of these contaminants are discussed.
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