EPROM baking

[dwight]

When I was at Intel, years ago, I recall the baking was only to repair the retention of the EPROMs. It was not to fix random failures.

It sounds like your EPROMs have various failures that wouldn't be helped by baking.

Each time the EPROM is programmed, there is a slight increase in the leakage of the floating gate. This was typical after thousands of program/erase cycles. Baking them repaired the damage to the insulating layer that was damaged.

Dwight


________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of william degnan via cctalk <cctalk at classiccmp.org>
Sent: Wednesday, December 13, 2017 6:18:16 AM
To: Mark G Thomas; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: EPROM baking

On Wed, Dec 13, 2017 at 9:08 AM, Mark G Thomas via cctalk <
cctalk at classiccmp.org> wrote:

> Hi,
>
> I am working on several projects requiring 2708 and 2716 EPROMs, and
> am finding some of my chips will not erase, and some will not take
> a program. I've also learned more in the past week than I wanted
> to know about repairing Data-I/O 29a/b programmers.
>
> I vaguely remember in the 1990s baking such EPROMs in the oven, but
> I do not remember temperature or time. I was surprised that Google
> didn't turn up anything useful with this info.
>
> I'm sure someone here will have some notes on EPROM baking.
>
> Mark
>
>
>

Mark,

If this is an issue about reviving bad eproms?  I assume you have tried the
regular stuff.

What process are you using now to erase 2708/16's?  I have a simple eraser
unit and it seems to always work.  Some eproms go bad but I never have
issues with erasing them.  My point is that maybe you need a better prom
eraser unit.  I would avoid baking them until you have exhausted other
options.  Not sure what others think.  This topic has come up before here,
about putting them outside and all that.  The erasers are all over ebay,
and the hardware store is full of the correct types of lighting, why not
make a box that will do the job?    I assume there is more to it that
simply erasing them.


Bill