1. Purpose of the gate
This gate turns a body of stress data into a claim that customers will rely on: that the device survives the stresses of its standard and that its wear-out mechanisms will not limit the life of the system it goes into. For a power device in an EV traction inverter or an industrial drive, that claim covers years of switching, temperature swings, humidity and high voltage. The review must test the claim, not just count passed stresses.
Passing every stress of AEC-Q101 is the start of the case, not the end. For silicon carbide, the gate oxide lifetime model and the threshold drift under the recommended gate voltages decide whether the device keeps its ratings over life. Body diode stability decides whether the device can be used for third-quadrant conduction. For gallium nitride, dynamic on-resistance and its stability decide whether losses stay within the datasheet. Ruggedness results for short circuit, avalanche and cosmic ray failure rate decide what protection and derating customers must apply.
The gate criteria are that the qualification stresses are passed to the chosen standard, that gate oxide lifetime and threshold drift are within the limits set in the plan, and that failures are analysed with root cause and corrective action. A failure written off without analysis is the most common reason for a hold, because it leaves an unknown mechanism in a product about to be sold.
10 more sections for registered members.