burn-in screening

**Burn-In Screening** is a **reliability test where packaged ICs are operated at elevated temperature and voltage for an extended period** — to accelerate infant mortality failures and screen out weak devices before they reach the customer. **What Is Burn-In?** - **Conditions**: 125°C ambient, 1.1-1.2x nominal voltage ($V_{DD}$), 48-168 hours. - **Purpose**: Accelerate latent defects (gate oxide weak spots, marginal solder joints) that would fail in the first weeks of customer use. - **Types**: - **Static Burn-In**: Powered but not clocked. - **Dynamic Burn-In**: Powered and exercised with test patterns (more effective). - **Bathtub Curve**: Burn-in eliminates the "infant mortality" region. **Why It Matters** - **Automotive / Mil-Spec**: Mandated by AEC-Q100 (automotive) and MIL-STD-883 (military/space) standards. - **Cost**: Very expensive (oven time, power, handling). Industry trend is to minimize or replace with alternative screens. - **Zero DPPM**: Goal of < 1 Defective Part Per Million for critical applications. **Burn-In Screening** is **the trial by fire for every chip** — stressing devices under harsh conditions to weed out the weak before they fail in the field.