Defect Elimination
Production quality stress tests accelerate the failure of weak components and poor solder joints that would otherwise fail during the first few weeks of customer use. This operation, termed infant mortality screening, subjects populated board assemblies to elevated environmental and electrical stresses to force latent manufacturing defects to occur during factory testing. By precipitating these failures early, manufacturers can rework or discard defective boards before they are shipped to end users.
The strategy reduces warranty claims and increases initial field reliability.
Thermal Acceleration
Thermal cycling combined with power burn-in provides the necessary stimulation to open weak solder connections and trigger marginal semiconductor junctions. During infant mortality screening, boards are run through rapid temperature transitions while operating at maximum voltage. This combination of thermal expansion mismatches and electrical stress quickly destabilizes any components that suffer from material defects or assembly errors.
It separates the weak population from the stable population before final packaging.
Screening Cost
Implementation of these stress cycles requires specialized chambers and increases the total manufacturing cycle time. While infant mortality screening adds cost to the production phase, it dramatically lowers the expenses associated with field repairs and customer returns. For critical medical, aerospace, and automotive electronics, this investment is necessary to maintain required safety standards.
