life testing

**Life testing** is **reliability testing that operates units over time to observe failures and estimate lifetime characteristics** - Test plans define sample size stress conditions and duration to derive hazard, survival, and confidence metrics. **What Is Life testing?** - **Definition**: Reliability testing that operates units over time to observe failures and estimate lifetime characteristics. - **Core Mechanism**: Test plans define sample size stress conditions and duration to derive hazard, survival, and confidence metrics. - **Operational Scope**: It is applied in semiconductor reliability engineering to improve lifetime prediction, screen design, and release confidence. - **Failure Modes**: Weak test design can produce inconclusive results and poor decision support. **Why Life testing Matters** - **Reliability Assurance**: Better methods improve confidence that shipped units meet lifecycle expectations. - **Decision Quality**: Statistical clarity supports defensible release, redesign, and warranty decisions. - **Cost Efficiency**: Optimized tests and screens reduce unnecessary stress time and avoidable scrap. - **Risk Reduction**: Early detection of weak units lowers field-return and service-impact risk. - **Operational Scalability**: Standardized methods support repeatable execution across products and fabs. **How It Is Used in Practice** - **Method Selection**: Choose approach based on failure mechanism maturity, confidence targets, and production constraints. - **Calibration**: Set statistically defensible plans and include failure-analysis feedback for model refinement. - **Validation**: Monitor screen-capture rates, confidence-bound stability, and correlation with field outcomes. Life testing is **a core reliability engineering control for lifecycle and screening performance** - It provides empirical evidence for reliability claims and risk assessment.