Fake or genuine 2SA1216 to x-ray or not

[405man]

I have some 2SA1216 / 2SC2922 and I can not decide if they are genuine or not, I have the opertunity to have them x-rayed as my wife is a radiographer, is this likely to damage the device, should I short the legs together or leave them open

Stuart

[DigitalJunkie]

They may end up damaged either way. Got a couple that you can spare?

[PChi]

I'm no expert but I have viewed Cellular phone PCBs mainly to check for correct BGA placement in an X ray machine (unfortunately I don't know the X ray level used) and no damage was done. It wasn't easy to spot anything useful though even with the board mounted so that it could be moved using a joy stick while being viewed in real time on a monitor.

[gmarsh]

They'll be fine to x-ray, leads shorted or not.

Lots of electronics are x-rayed after manufacture to check for things like BGA alignment (as PCHi mentioned), and airline baggage also gets X-rayed without any damage to electronics inside.

[KBK]

Originally Posted by 405man

I have some 2SA1216 / 2SC2922 and I can not decide if they are genuine or not, I have the opportunity to have them x-rayed as my wife is a radiographer, is this likely to damage the device, should I short the legs together or leave them open

Stuart

I'd be grateful if you would do an A/B with two sets. (in possibly a different way with a different set of transistors)

A before and after comparative. ie, design a set up so that irradiated vs non irradiated transistors could be blind tested against one another in not just an identical circuit.... but the same circuit.

This could prove to be very interesting.

Build a circuit, test two sets. Hopefully one arrives at a conclusion that both sets of transistors-----sound the same.

irradiate one set.

Test both sets again. See if any differences are heard.

If differences are heard, go to the next level.

Set up an unbiased DBT test, composed of of 'reasonable' people, ie, people who do understand that differences might be heard. people who do hear differences, regularly.


In this case, socketed transistors remove all aspects of potential error, like the DBT switching devices and cables,and this would even be the exact same circuit used in each.

Thus the only differential is the transistors themselves. A true single cause analysis situation.

[jitter]

Originally Posted by PChi

I'm no expert but I have viewed Cellular phone PCBs mainly to check for correct BGA placement in an X ray machine (unfortunately I don't know the X ray level used) and no damage was done. It wasn't easy to spot anything useful though even with the board mounted so that it could be moved using a joy stick while being viewed in real time on a monitor.

We have sometimes made good use of an X-Ray machine in comparing counterfeit with genuine ICs.

When it comes to inspecting BGAs, ours is good at detecting shorts and voids, but it's impossible to tell if a ball is or isn't soldered to the pcb.
It indeed doesn't harm the electronics.

@405man
What kind of machine do you have access to? Is it good at looking at very small objects?

[scott wurcer]

Originally Posted by 405man

I have some 2SA1216 / 2SC2922 and I can not decide if they are genuine or not, I have the opertunity to have them x-rayed as my wife is a radiographer, is this likely to damage the device, should I short the legs together or leave them open

Stuart

You won't be able to see much more than if it's bonded and the die size.

[405man]

Thanks for the input, I am on holiday for a couple of weeks but shall get it done when we get back and post the results

Stuart

[jitter]

Any news?