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 >