Is there any way to "look through" a circuit board which
has traces inside (multilayer)?
I tried making the layers visible with a lighttable, but
the board is simply not thick enough to let enough
light pass.
Any other way to look inside a board or other object?
I thought of infrared light, but no idea how to make that
visible on the other side.
This sounds strange, i know, the circuit board is just an
example, another example may be, how to show the
metal in security cards, bank notes, check for printing
under a label without removing the label, and so on.
A third example may be, i have 2 pieces of black paper.
inbetween i put a piece of newspaper.
Light should not pass, but is there a way to make the
text visible?
Again, sounds weird, i know, but i have a good reason
for it.
As well, can electric current in a board made visible ?
To check for broken traces, continuity problems, and
so on.
Someone claimed he did all above but refuses to say how,
but i know he uses a computer scanner and something on
top of the object, that´s why i thought of infrared.
Any ideas?

Bart Bervoets