Infant mortality covers failures that occur soon after a product enters service because of latent defects: weak oxide, marginal wire bonds, contamination, cracked solder joints. On a Weibull plot these failures give a shape parameter below 1, a decreasing hazard rate. Burn-in, screening and tighter process control target this region, and a surge of early returns usually points back to a specific build lot or excursion.
Eighty percent of the returns failed inside 30 days. That's infant mortality, so look at the build lots, not the design.
Also heard as
- early life failure
- ELF
- early failure
Related terms
Bathtub curve
Plot of failure rate over a product's life: falling early failures, a flat random period, then rising wear-out.
Burn-in
Operating products under raised stress before shipment so weak units fail in the factory instead of in the field.
Shape parameter
Weibull beta: the slope of a Weibull plot, which shows whether failures are early-life, random or wear-out.
Excursion
Sudden departure of yield, defect counts or a key parameter from its normal band, big enough to trigger holds and an investigation.