Staging & Prognostic Factors Flashcards

Mean Time Between Failures (MTBF) is a key prognostic metric. If a component has a failure rate of 0.001 failures per hour, what is its MTBF?

Answer: 1,000 hours

MTBF = 1 / failure rate = 1 / 0.001 = 1,000 hours.

The 'bathtub curve' in electronics reliability describes:

Answer: Three phases: infant mortality, useful life, and wear-out

The bathtub curve plots failure rate over time, showing high early failures (infant mortality), a flat useful-life period, and increasing wear-out failures.

Which environmental factor is considered the single greatest accelerant of electronic component failure?

Answer: Heat (elevated temperature)

Elevated temperature accelerates chemical reactions, electromigration, and material degradation, making it the leading factor in component failure acceleration.

Accelerated Life Testing (ALT) subjects components to elevated stress levels in order to:

Answer: Predict long-term reliability in a shorter test time

ALT uses elevated temperature, voltage, or humidity to compress failure timelines so that long-term reliability can be predicted quickly.

In electronic component reliability, 'derating' refers to:

Answer: Operating a component below its maximum rated parameters to extend life

Derating means operating a component at a fraction of its maximum rating to reduce stress and improve reliability and lifespan.

Electromigration is a dominant failure mechanism in integrated circuits primarily affecting:

Answer: Metal interconnect lines carrying high current densities

Electromigration causes metal atoms in interconnects to migrate under high current density, eventually causing open circuits or shorts.

Which MIL-HDBK standard is most commonly referenced for electronic component reliability prediction and failure rate data?

Answer: MIL-HDBK-217

MIL-HDBK-217 provides failure rate models and data for electronic components used in reliability prediction.