Paul:
This can be done in cases where a company that owns the design of the manufactured PCB needs to recreate electronic artwork files. This would apply only and specifically to cases wherein the original electronic artwork files were lost, destroied, or stolen.

Duplication of the board artwork by parties other than the design owner is not a legal activity.

Now, all that said, I can comment that it turns out that it is almost always easier and less costly to recreate a board artwork by re-doing the CAD work in a good quality PC board layout package.

The technigues used by rip-off artists that try to copy some other company's boards generally use a photographic duplication process. First all components are removed from the board and then the surface on each side is sanded and buffed down to the bare copper and raw glass epoxee substrate material. The photo process can then make a new photo plate from the copper image. Sometimes it is necessary to increase the contrast between the copper areas and the substrate media. This may done with dies, plating on the copper or backlighting of the board. If a board is a multi layer assembly then after outside layers have been processed the sanding and buffing process is continued to expose the inner layers one-by-one. As these inner layers become exposed they are photoed in much the same manner as the outer layers were handled.

It is almost for sure that in the advent of the high speed/low cost computers and high resolution scanners that some of the rip-off artists are now using a digital scan to bitmaps rather than using the photographic methods to image the exposed copper areas. It is even possible to anticipate that some rip-off artists are using bitmap to vector tracing software to re-create vector based PCB artwork data.

Michael Karas