Failure Modes of Beam-Lead Semiconductors in Thin-Film Hybrid Microcircuits

Beam-lead semiconductor and passive devices have been utilized in hybrid microcircuits (HMC) to provide higher reliability. This is derived from the beam-lead device´s improved bonding integrity plus the silicon nitride coating which reduces sensitivity to contaminants; however, their size requires special handling techniques to prevent handling damage. Other failure modes exist such as cracked nitride, pinholes in the nitride, inadequate plating, and smeared metallization. After two years of production usage totaling approximately 150 000 devices, The Bendix Corporation´s Kansas City Division has compiled significant data on beam-lead devices including small-signal and power discrete semiconductors and digital integrated circuits. These failure modes are characterized and precautionary measures are described to minimize failures in HMC usage.