System and method for unveiling targets embedded in a multi-layered electrical circuit

摘要

A system for unveiling embedded targets in printed circuit board substrates includes a micro-machining device, a sensor, and a controller. The micro-machining device removes portions of an opaque layer overlaying an alignment target in a general region in which the target should be located, and the sensor senses whether the alignment target is located at selected locations where portions of the opaque layer have been removed. In response to sensing the presence or absence of an alignment target at the selected locations, the controller directs the micro-machining device to remove additional portions of the opaque layer.