Production Screen
Production tests subject every manufactured unit to rapid thermal and mechanical stresses to expose latent manufacturing defects. The implementation of highly accelerated stress screening occurs during the manufacturing phase to catch workmanship errors before products ship. Unlike long-term reliability tests, this screen uses extreme conditions to force early failure in weak components or poorly soldered joints.
It identifies issues like cracked solder balls or loose connections that might survive standard functional testing but fail shortly after deployment. This methodology ensures that any variance in the assembly process, such as incorrect soldering heat or inadequate pressure, is caught before the product reaches the end user.
Stress Application
Units are placed in a specialized chamber capable of thermal ramp rates exceeding 60 degrees Celsius per minute. Simultaneous multi-axis vibration adds mechanical load to the electrical stresses of power cycling. This combination reveals flaws that single-axis or static tests often miss.
Safety Margin
Profiles for this screening are derived from earlier development testing to ensure the stress level does not consume too much of the product’s useful life. The screen must be aggressive enough to find defects while remaining below the fundamental limit of the design. If the failure rate during the screen increases, it indicates a shift in the manufacturing process rather than a design flaw.
