Brads Electronic Projects Forum

Chips vulnerable to light without the protective casings?


http://hackaday.com/2016/05/05/dont-tak ... sensitive/

https://www.raspberrypi.org/blog/xenon- ... cs-lesson/

When I attended a Microchip PIC seminar in the mid 1990's (when they were all EPROM-based, not flash, so erasable ones had a window), we were told to keep the window in the package covered even when programming so it would work right, even though leaving it uncovered would not give nearly enough light in the short amount of time to cause any erasure. Ten years earlier however, I worked in applications engineering at a VHF/UHF power transistor manufacturer, mostly in power MOSFETs, and we regularly had light on the bare dice when they were in circuits putting out their RF power. I suppose the much greater thickness of the layers in the silicon prevented trouble. The MOSFETs put out up to 150 watts each, continuously, at 175MHz. The bipolar transistors put out up to a thousand watts each (pulsed), at 450MHz IIRC. The pulsed ones were for military radars.

That's quite interesting and such a huge drop in voltage too!

I wonder why this wasn't picked up before? Could it possible have been known to the manufacturer and they still just release the chips?