It is true that semiconductors and quartz crystals are affected by
x-rays, however, for your situation I doubt there is problem.  Typical
x-ray exposures for failure analysis are established by the sensitivity
of your film.  If you overdose your film, I still doubt you would exceed
the noticeable damage levels for components.  Remember, UV erasable
PROMs are erased by ultraviolet light.  X-rays would do the same.
Therein lies the problems.  X-rays ionize the SiO2 creating
electron-hole pairs.  Either a pn junction's built-in potential or an
applied bias separates the oppositely charged particles.  One of the
more noticable effects is holes migrating to the substrate
silicon/silicon-dioxide interface beneath the gate in an n-MOS
transistor.  The holes get trapped in the interface and still carry a
positive charge.  If there is enough positive charge, the transistor
will remain 'on' due to this parasitic electric field not controlled by
the gate.  Bipolar devices have similar problems.

Typical x-ray exposures are on the order of 1 rad or less (a rad is a
measure of absorbed energy, 100 ergs/gram) and most devices survive at
least 1000 rads.  Space electronics must survive this and more, i.e.
tens to hundreds of thousands of rads.

As for in-line systems, the exposure times are pretty modest.  No
different than the airport security x-ray systems.  Plenty of
electronics gets x-rayed every day that way!



> ----------
> From:         Gabriela Bogdan[SMTP:[log in to unmask]]
> Sent:         Wednesday, August 27, 1997 1:39 PM
> To:   [log in to unmask]
> Subject:      [TECHNET] X-RAY DAMAGE TO COMPONENTS
>
> Curiosity killed the cat.
> Hi,TechNetters!
> I was very proud of my new X-Ray system for failure analysis, and
> during the demonstration of its capabilities, I tried to check a
> crystal
>
> component which I suspected broken.The appliccation engineer warned
> me that I may damage the component during the test.
> Is this a known fact?
> What about in line systems through which such components pass
> all the time?
> If so,are there also other components which are sensitive to X-Ray?
> Please answer me soon if you have the information!
> Thank you,
> Gaby
>