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

I'm game;

What you need to do is to find something in the EM spectrum that can
upartially/u pass through the copper, but pass cleanly though the PCB
material. This is to keep the depth of focus very shallow. Similar to the
technology used on dual layer DVDs, it's like having two fiches in the
microfiche reader, if they're mostly white, with say a reasonable amount of
black text, you can switch views simply by changing the focus.

Focus is on the detection end, so if there aren't huge ground planes the
requirements might just relax a bit.All in all, you're salking about some
money, some wierdo "light" source and a special camera to pick it up, and a
highly accurate focusing system. That's IF you can get something through that
copper. I don't know that they can focus Xrays that well, but realistically I
don't know that they can't. Possible Beta rays, but then even if they can focus
Xrays, this might not be so with Beta rays.

Using either brings up another frustration, if you expect to use Xrays or
something like that on a PCB with the components installed I don't think it'll
work afterwards. Xrays do funny things to semiconductors.

Just how important is this ? and there is absolutley no other way to get the
info you need ? What you're talking about here is not cheap.

JURB

"JURB6006" bravely wrote to "All" (15 Mar 04 23:28:41)
--- on the heady topic of " Layers in circuit board and current."

Would you think UV rays, such as from an eprom eraser, that I know can
penetrate very thin copper material, would be safer to experiment on
than X-rays?

JU From: (JURB6006)

JU I'm game;

JU What you need to do is to find something in the EM spectrum that can
upartially/u pass through the copper, but pass cleanly though the PCB
JU material.

.... No electrons were harmed in the posting of this message.