Burn in Hours Charged against the Product Life Remaining
Accelerated burn in hours deduct directly from product life reserves based on activation energy kinetics and must be contractually capped to prevent premature field wear out.
Dynamic Stress Screening
Defect Stimulation
Environmental testing protocols for completed circuit assemblies often utilise rapid thermal transitions and multi-axis random vibration to expose latent manufacturing defects before shipment. This process, known as dynamic stress screening, forces early failures in solder joints and wire bonds by applying controlled mechanical and thermal forces. By operating the device under functional load during these transitions, marginal connections that would otherwise pass static tests are exposed.
The stimulus levels are calibrated to remain below the fatigue limit of healthy materials, ensuring that only pre-existing flaws are triggered.
Electrical Monitoring
Continuous parametric measurement of the board under test detects intermittent failures that disappear once the stress is removed. Hardware systems executing dynamic stress screening capture transient voltage drops and resistance spikes in real time. These measurements pinpoint cold solder joints and cracked ceramic capacitors.
The captured telemetry guides rework teams to the exact physical location of the anomaly, reducing diagnostic time and preventing the escape of intermittent faults to the field.
Screening Efficacy
The determination of screening duration relies on a trade-off between defect precipitation and accumulated fatigue. Extended exposure to dynamic stress screening consumes a portion of the operational life of the printed circuit board. Successful execution reduces infant mortality rates in harsh deployment environments.