TLC556: TLC556MD

Norm,

Failure analysis labs commonly for use X-rays for initial inspection. So it seems that X rays used properly do not cause damage.
Do you suspect the TLC556 is damaged in some way? The manufacturer for your X-ray should have more guidance.

Hello Ron,
That is the suspicion. We had 2 TL556 failures previously on a board after x-raying as part of an out of timing spec investigation.
Thank you for the feedback.

Norm,

Try baking the parts at 150C for a few hours (with the power off) to see if they recover. There are no memory bits in TLC556, but thresholds in the comparators could affect operation. Baking could reduce any ionization shifts in transistor performance.

Try looking up "Considerations for Minimizing Radiation Doses to Components during X-ray Inspection "
Table 1 shows a wide range in X rays doses to cause failure in various types of integrated components.

Hello Ron,

It turns out the circuit card using the TLC556MD suspected of x-ray damage was not just a 2-D inspection but a CT scan  was performed.

Industry information I have found does not seem to be very specific about CT scan effects.

 This has some good back round information. Sec. 3.2.1 is about Radiation Effects.

http://www.dtic.mil/dtic/tr/fulltext/u2/a217976.pdf

Do you have any suggestions on references for CT scan effects ?

Thanks

Norm

Norm,

CT are X ray scans. That's all I know.