Metal electromigration induced by solder flux residue in hybrid microcircuits

Electrical failure due to excessive current leakage was observed in a hybrid following burn-in. The current leakage was a result of extensive metal electromigration between substrate conductors which had been correlated with flux residue in the device. It has been determined that water and other species are produced by thermal degradation of the flux during burn-in at 125 degrees C. Failure-analysis results along with associated materials and electronic testing are reported.<
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