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IP.com Disclosure Number: IPCOM000008368D
Original Publication Date: 1997-Dec-01
Included in the Prior Art Database: 2002-Jun-11

Publishing Venue


Related People

P. S. Collis I. D. Cairns


The design of printed circuit boards (PCBs) has become a completely computerised process. The final output that is used to manufacture a PCB is a particular data file format, namely a GERBER format. This data is then plotted on photographic film, typically ten to twenty sheets are used. Using a 6 layer PCB, as an example, we find that there are four sheets of tooling photography needed in the process to produce the inner layers. The selection of these four sheets is a manual process and inevitably the PCB layers can be swapped. Final boards with swapped internal PCB layers may still work and will pass simple continuity tests because no connec- tions have been broken.