Electronics > Beginners

Noob question: can high temperature during soldering kill/erase an EPROM chip ?

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JLL:
Hello,

I'm currently trying to debug an issue I have and was wondering if high temperature could be the cause of my problem.

Context: I'm building a SFC cart repro for the Gradius 3 SA-1 enhanced mod.
I built two carts: one with a ZIF socket so I could test the EPROM chip quickly (27C322 chip) and a 2nd one so I could solder the chip directly on it.
I have confirmed that the chip works and was written to successfully using the debug cart.

But then after soldering the chip on the 2nd cart, it didn't work at all. Since I had to cut the legs on the chip, I cannot insert it on the debug cart anymore to test it.

While I was soldering the chip on the 2nd cart, I made a bit of a mess and took way longer than I would have liked: dozens of seconds instead of just a few per pin, at 300 degrees (celcius). I noticed the chip very very hot (I could not touch it without getting burned).

Could this have altered the data stored on the chip or killed it in some way ?

Thanks in advance for the feedback.

Jwillis:
I don't think they like a lot of heat. I've only used sockets for this type of sensitive chip. But that was years ago.

T3sl4co1l:
Unlikely. Even modern Flash (very tiny cells holding multiple levels of charge) can usually be resoldered with e.g. hot air machine (since we'd be talking SMT parts where the whole body reaches soldering temp).

If that's a ceramic body EPROM, the heat will be effectively sunk by the body, so the die doesn't see extraordinary temps.  It might've still been within rated storage temp, though still very much untouchably hot.

Might not hurt to check its contents or re-burn it though.  Also possible you zapped a pin or something.

Tim

JLL:
Thank you for the info. I'll find a way to test/reburn it.

Brumby:
I winced at this

--- Quote from: JLL on February 17, 2020, 08:47:52 am ---... and took way longer than I would have liked: dozens of seconds instead of just a few per pin, at 300 degrees (celcius). I noticed the chip very very hot (I could not touch it without getting burned).

--- End quote ---

Certainly, electronic components of all sorts must withstand soldering temperatures - but they always have a time limit next to the temperature limits.  I've seen 10 seconds at 300 (and something) degrees Celsius for a lot of things, but some are more resilient ... and some less.

Between 1 and 3 seconds per pin is my normal range - and I think it's the same for most.  For multi pin packages, I tend to pause every few pins or so, to limit the thermal assault.  The thought of "dozens of seconds" per pin is toothache territory.  This can allow heat to find its way to the active region where it can degrade or destroy the function of the component.

From your description, I am inclined to think it has been "baked".

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