Aim of Process
The aim of this process, is to detect any circuit defects before they are built inside the multilayer package, this is done by electronically digitising the image on the inner layer core and comparing it against the net list derived from the customers design. This will detect the following faults
Open Circuits, Short Circuits, Spurious Copper, Dishdowns , Nicks/pinholes in tracking, Distortion of circuit image, Registration of circuit image.
The net list file is extracted from the network, and the first side is set up on the A.O.I. ( automatic optical inspection ), and the image is then and compared electronically against the net list, if there is a defect it is displayed in both, the computer interpreation of the defect, and in the actual image on a video monitor. If there are defects the machine shows the core as a pass, this is repeated for all layers on all the cores. Every core of every layer is 100% inspected by this method.