Wear-out failures occur late in product life from gradual degradation — the final bathtub curve region where cumulative damage from electromigration, dielectric breakdown, and mechanical fatigue causes increasing failure rates.

What Are Wear-Out Failures?

• Definition: Failures from accumulated degradation over time.
• Bathtub Curve: Final region with increasing failure rate.
• Timeframe: After years of operation, near end of design life.

Mechanisms: Electromigration (metal migration), TDDB (oxide breakdown), mechanical fatigue (solder, wire bonds), corrosion, thermal cycling damage.

Why It Matters: Warranty expiration timing, maintenance scheduling, end-of-life planning, safety-critical system replacement.

Prevention: Design for reliability (DFR), derating (operate below max ratings), periodic maintenance, replacement schedules, reliability simulations (FMECA, FEM).

Prediction: Accelerated life testing, physics-of-failure models, Weibull analysis, field data tracking.

Design Considerations: Keep currents and temperatures within safe ranges, use redundancy for critical functions, plan for graceful degradation.

Monitoring wear-out is essential for warranty planning — ensuring products don't fail before expected lifetime and maintenance schedules are appropriate.