Meaning
Quantifiable reduction in the number of functional semiconductor units resulting from stress testing during the infant mortality phase of production. These burn in yield losses represent components that fail under accelerated thermal and electrical loads before they leave the factory. Measuring these failures allows manufacturers to prevent defective parts from entering the supply chain.
Stress Mechanism
Elevated temperature and voltage levels force latent defects to surface quickly. When a batch undergoes these conditions, burn in yield losses often stem from dielectric breakdown or metallic migration issues that would otherwise appear months later in the field. This process acts as a screening filter rather than a refinement of the material itself.
Production Impact
High failure rates during testing directly increase the unit cost of the surviving parts. If burn in yield losses exceed the budgeted percentage, the facility manager must investigate the wafer fabrication stage for contamination or process drift.
Economic Penalty
Discarding failed units represents a loss of raw material and energy invested in the manufacturing cycle. Because burn in yield losses occur at the final stage of assembly, the financial impact per unit is at its maximum. Continuous monitoring of these data points informs the decision to adjust the burn in duration or the intensity of the stress applied.
