fixed-time life testing

**Fixed-time life testing** is **life-testing approach where units are tested for a predetermined duration before reliability decisions are made** - All samples run to the planned endpoint unless catastrophic criteria require early termination. **What Is Fixed-time life testing?** - **Definition**: Life-testing approach where units are tested for a predetermined duration before reliability decisions are made. - **Core Mechanism**: All samples run to the planned endpoint unless catastrophic criteria require early termination. - **Operational Scope**: It is applied in semiconductor reliability engineering to improve lifetime prediction, screen design, and release confidence. - **Failure Modes**: Fixed duration may be inefficient if decisions could be made earlier with adequate confidence. **Why Fixed-time 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**: Choose duration from target reliability and confidence objectives, then verify power under expected failure rates. - **Validation**: Monitor screen-capture rates, confidence-bound stability, and correlation with field outcomes. Fixed-time life testing is **a core reliability engineering control for lifecycle and screening performance** - It offers simple execution and straightforward reporting.