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Full Version: OT: Cal-Tex or "How to remove the lid of an old IC"?
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Still puzzled about the manufacturer of the weird Unitrex 800K calculator chip and we decided to sacrifice one...

Short question: How to we remove the lid of a DIL package w/o destroying the chip?

Suggestions welcome.

Have a great week.


I think a sharp knive will work out fine - at least that's how I did it before. If you trash your IC, I'll find another...


Sounds great. We could trade the chip for a TI-88 ;-))

Dir noch einen schoenen Sonntag / Have a great Sunday.


From experience, that could be a very risky task: In doubt ask Peter Nusser, cpu-galaxy.at.

"Nobody does it better..." Look and see!



Edited: 6 May 2012, 2:26 p.m.


I have seen some IC's being cut and have their lid removed (Martin's proposed link to www.cpu-galaxy.net in one of the follow-ups has some very good examples), but what are the odds of having a sealing resin compound glued to the lid that would destroy the chip if the lid is removed? Isn't there a way to check for solid contents with some modern scan technology prior to try to remove it? If the chips are rare and one can be sacrificed, why not to make sure it is done accordingly?

My thoughts, though.

Luiz (Brazil)

Edited: 6 May 2012, 6:27 p.m.

I've never yet heard of a metal-lid package that didn't have an open cavity containing the part. That's the reason the metal lid is necessary. If you seal it in resin, it doesn't need a metal lid.

I'm not sure if the value justifies a former non-destructive inspection - as long as you don't have you own x-ray equipment ;)

if you can get the lid to tin (just with normal solder), then a hot soldering iron will heat it up sufficiently to melt any gold-based solder OR soften the resin that appears to be holding it in place.

a neat trick with 2-part epoxies (araldite) is to place the glued item in boiling water - the epoxy will (often) disintegrate.