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Path: utzoo!watmath!clyde!bonnie!akgua!mcnc!decvax!decwrl!sun!idi!t4test!chip
From: chip@t4test.UUCP (Chip Rosenthal)
Newsgroups: net.lsi
Subject: Re: HELP!  What are these chips?
Message-ID: <1247@t4test.UUCP>
Date: Fri, 16-Nov-84 14:20:25 EST
Article-I.D.: t4test.1247
Posted: Fri Nov 16 14:20:25 1984
Date-Received: Sun, 18-Nov-84 05:38:19 EST
References: <357@mako.UUCP> <1636@wateng.UUCP> <251@spp2.UUCP> <3373@rochester.UUCP>
Organization: Intel Corp./Santa Clara
Lines: 26
Summary: opening plastic packages

> From: ken@rochester.UUCP (Ken Yap)
> Date: 13 Nov 84 17:23:34 GMT
> 
> In article <251@spp2.UUCP> heiss@spp2.UUCP writes:
> >On cracking open chips: the ceramic-sandwich packages are easily split
> >with old diagonal cutters, but what about the plastic packages?  What tool
> >or chemical will expose the silicon for viewing?
> >
> You probably need a chemical that will dissolve the plastic (if such
> a chemical exists). These things are totally encapsulated (i.e. no cavity
> inside).

If anybody really wants to know what the chemical is, send me mail.  I
could check with the quality engineering lab.  Those folks are always
opening parts for inspection.

While I don't know the name of the chemical offhand, I do know it is
a difficult process to etch back the plastic without damaging the die
or lead frame.  But I suppose if you are opening cer-dips with diagonal
cutters, you aren't real concerned with cracking open a chip without
damaging it.

-- 

Chip Rosenthal, Intel/Santa Clara
{cbosgd,idi,intelca,icalqa,kremvax,qubix,ucscc} ! {t4test,t12tst} ! {chip,news}