Xref: utzoo comp.lsi:1055 sci.electronics:12251
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From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: comp.lsi,sci.electronics
Subject: Re: reverse engineering
Summary: Hazardous chemicals can often do the job...
Keywords: epoxy removal
Message-ID: <3785@kitty.UUCP>
Date: 6 Jun 90 04:44:35 GMT
References: <778@fornax.UUCP>
Distribution: na
Organization: Recognition Research Corp., Clarence, NY
Lines: 30

In article <778@fornax.UUCP>, donaldo@fornax.UUCP (Don Smith) writes:
> I would like to reverse engineer a calculator watch but am having
> a hard time removing the epoxy coating the chip.  So far I have 
> tried a number of chemicals including: 
>    acetone

	If you are dealing with a true epoxy compound (as opposed to say,
a thermoformed polymer), you are generally barking up the wrong tree using
acetone or other ketones (such as MEK, methylethyl ketone).

>    and hydrochloric acid.
> The hydochloric acid removed the epoxy but also damaged the chip.

	Not at all surprising!

> I would appreciate the names of chemicals which
> can break up cross linked polymers without damaging the chip.  The
> watch is an inexpensive OEM type watch costing about $10.

	I can give you the names of two chemicals to try which I have
personally used in years past for this purpose: dimethylformamide (DMF)
and 1,4-dioxane.  Your mileage will vary depending upon the actual
epoxy that has been utilized.  HOWEVER, THESE CHEMICALS ARE EXTREMELY
HAZARDOUS and should only be used in a properly constructed fume hood
by technically competent persons.  Don't even THINK of trying to use
these chemicals at home!

Larry Lippman @ Recognition Research Corp.  "Have you hugged your cat today?"
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