X-ray analysis to verify that the internal lead frames, bonding wires and dice construction is consistent within the lot and against known good devices if possible. Die size, general shape, lead frame construction, wire bonding gauge and routing can be checked. In general, there should be no variation in parts with the same date and lot code. Radiographic films (or digital images) of each device are retained. If any anomalies are noted in the sample of the lot, 100% of the lot should be inspected with X-ray.
(Note: Typically NOT a Destructive Test if the radiation exposure does not exceed the manufacturer's specification. X-ray used by AAA exposes devices to < 50mRAD, ~ 1/40,000th the level most semiconductors start to experience radiation damage.) AAA recommends 45 samples from each lot be X-Rayed.