Qualification
Beginner
A series of stress tests that show a chip will keep working for years, required before it is sold in volume.
Novice
A fixed set of stress tests on chips from several separate production batches: running them hot for long periods, cycling them between extreme temperatures, and more. Passing usually means zero failures. Customers require it before buying in volume.
Expert
Sample sizes, batch counts and conditions come from the standard the customer requires, such as AEC-Q100 for cars. Changes to the design, process or package can trigger requalification.
Explained in After tapeout (Extras).
See also: HTOL (high temperature operating life), AEC-Q100.