1. Purpose of the gate
Every stress in the qualification plan has passed, parametric drift after stress is within limits, and every failure is analysed and dispositioned.
Passing qualification means more than surviving stress. The gate looks at each calibrated parameter, offset, sensitivity and their temperature behaviour, before and after each stress, and checks that the shift is within the limits the specification allows. It also checks that MEMS specific mechanisms were exercised and are under control: stiction after shock and humidity, spring fatigue under vibration, seal leaks that change damping, and corrosion or blocking of open ports.
Every failure is analysed to a root cause with an action. A failure set aside as unexplained is a mechanism waiting to appear in the field. Where the cause lies in the process, package or calibration, the action and any requalification needed are agreed before release.
The gate also confirms that the qualification evidence matches what customers will ask for: test reports to the named standard, AEC-Q103 test groups where they apply, and the summaries that go into production part approval.
Reviewers should also look forward. Mechanisms that appeared near their limit in qualification are candidates for production monitoring, and the gate should agree which stresses continue as periodic reliability monitors so that a later process or material change that worsens them is caught.
Where qualification was run partly by similarity to an earlier qualified sensor, the gate checks the justification: which parts of the design, process, package and calibration are shared, which differ, and which stresses were rerun to cover the differences. Customers and auditors read these justifications closely, so they must be specific.
10 more sections for registered members.