> Bill Dworak, on Wednesday, 2/23/2000 wrote
I have a part that my customer wants to manufacture a pcb, and a pcb is
all that they have no data no other info at all, this company just
purchased a littler company and the people that were involved with this
certain project are no where to be found not to mention that it is in a
different country.
What my question is can a finished product like this be reverse
engineered so that they can produce the proper data and whatever else is
needed to mass produce them? It is a pcmcia (4 layer) they have about a
dozen of them. Any help would be greatly appreciated.
========================================================================
Bill,
From days long ago, I can supply a tried and true system, depending on the
complexity of your CCA.
As it is only a PC-Card (formerly PCMCIA) 4 layer, this method should work
well.
equipment list:
ohm-meter with buzz, or a buzz box
2 standard sharp probes
alligator clip adapter for sharp probe
piece of copper braid (1/4" - 1/2" wide)
method:
make a component layout drawing, complete with pins.
create component designations and assign pin numbers.
discretely remove and bag each component with its component designation.
Give bagged components to your component engineer for proper identification.
take the now depopulated PWB and inspect for solder shorts and other damage.
map the existing circuitry in the bare pwb as follows.
starting in the lower left corner, apply probe to pin one and use copper braid
attached by alligator clip to SCAN the pwb for the other pin-outs on the
circuit. When you get a hit, localize as best you can with the braid, then
switch to a second needle probe to determine exact component and pin.
write it down as follows: U1-1 to U12-5
continue until each pin has been checked, and don't forget to scan the far
side.
Now go create schematics, insert component definitions, etc, and create an
entire new CAD package
back in the mid '80s, when I built mostly flight hardware, the prototypes were
so expensive, that we took the time to hand verify the artwork (much still
hand laid out due to design complexity) and the raw pwb against the schematic.
If you have the schematic, you just highlight the connections as you verify
each one, and then use the braid to verify circuits aren't shorted together.
That method only took several hours. I think you will spend a great deal more
than that.
Good Luck'
Steve Mikell
SCI Systems
Huntsville, AL
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