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Path: utzoo!utgpu!water!watnot!watmath!clyde!cbatt!ihnp4!ihlpf!straka
From: straka@ihlpf.UUCP
Newsgroups: sci.electronics,rec.video
Subject: Re: Soldering in MOSFETs
Message-ID: <1384@ihlpf.ATT.COM>
Date: Thu, 9-Apr-87 08:37:16 EST
Article-I.D.: ihlpf.1384
Posted: Thu Apr  9 08:37:16 1987
Date-Received: Sat, 11-Apr-87 15:45:30 EST
References: <270@lpi.UUCP>
Organization: AT&T Bell Laboratories - Naperville, Illinois
Lines: 25
Keywords: MOSFET, static
Xref: utgpu sci.electronics:476 rec.video:809
Summary: MOSFETs, static

In article <270@lpi.UUCP>, davidw@lpi.UUCP (David Weisman) writes:
> I'm replacing the RF amp MOSFET in a TV and want to doublecheck the procedure
> for soldering these things.  Besides the obvious heatsinking, I'm curious
> about the static problem.  I know about using a grounded soldering iron, but
> should I also ground the TV chassis?  Could there could be a static 
> potential between "earth" ground and TV ground???

> Should I also be standing on a static-shorting mat?  etc??

The idea here is to remove ANY possibility of putting a static potential
across the leads of the MOSFET or between any of the leads and the case.
That is why they are shipped in foil or otherwise conductive packaging
if they are even possibly sensitive.

My suggestion is to MAINTAIN a conductive path between each of the leads
and the case until the device is securly soldered into place with all of
the other circuitry.  This can be done by attaching clips or something
conductive to the leads and case while the device is STILL in contact
with its packaging.  When handling the device, try to make sure that you
do not build up any static potential relative to the device.  When you
finish the soldering, you can then remove the shorting equipment.


-- 
Rich Straka     ihnp4!ihlpf!straka