Effect of Outgassing of Wire in Sealed Storage Bags

摘要

Sporadic cases of corrosion in electrical connectors have been found when the prewired connector assemblies were removed from factory sealed bags. In all such cases the corroded parts were terminated to wire per MIL-W-22759/33, the insulation being Ethylene-TetraFluoroEthylene (ETFE).rnTesting and analysis using advanced techniques such as lon Chromatography, Scanning Electron Microscopy (SEM) and Fourier Transform Infra Red (FTIR) Analysis have been applied to examine the wire insulation, the contacts and their plating, the metal shells and plating and finally the packaging bags.rnAll of the evidence indicates that exposed platings have reacted with fluoride ions from hydrofluoric acid formed by unpolymerized fluorides present in the wire insulation.rnThese excess fluorides and other volatiles can be removed by subjecting the wire to elevated temperatures. This must be done prior to sealing the wired assemblies in bags or any vessel or chamber where the volatiles would be trapped and in proximity to metals.