The A.O.I. test verifies the finished conductor trace image for deviations from the Gerber data and finds errors that the E-Test may not discover, such as (for example) narrowed, but still unbroken conductor traces.
The A.O.I. test is especially important for the following application areas
The inner layers of multilayer boards are checked using A.O.I. before they are pressed together. This guarantees the high reliability of Multi-CB multilayer circuit boards.