A Pyrolytic Method for the Identification of Transmutable Conductive Bridge Contaminants on Metal Film Resistors

A method to identify conductive bridge contaminants has been developed using pyrolytic and chromatographic principles. A known contaminant is deposited on the surface of a metal film resistor and placed in a glass test fixture. A load is applied to the resistor with a powerstat until the material becomes active. A sample is taken of the gaseous products and analyzed with a gas chromatograph. Distinct and characteristic patterns emerge for the various common contaminants. A manufacturer could follow the same procedure 'to establish "standard" chromatograms for contaminants in his process. Periodic lot checks would enable him to locate and isolate the specific contaminant.