Stuffing boards with pulled QFP chips

Chuck Guzis cclist at sydex.com
Sat Apr 1 20:59:54 CDT 2017


On 04/01/2017 07:01 AM, Paul Koning via cctalk wrote:

> 
> Before building my most recent project (which involves an
> unpleasantly small-pitched TSOP package housing multiple RS232 level
> converters) I asked experts at work (technicians who do a lot of fine
> detail soldering) about RoHS.
> 
> The answer was very clear.  If you must use that stuff because of
> regulations, that's one thing.  If it's for your own use and the
> rules aren't applicable, don't be silly, use real solder.

That goes for repairing things also.   I owned a Volvo in the late 90s
that would develop strange electrical problems, such as the headlights
suddenly not working.  The culprit was the Bosch relay modules, many of
which had small PCBs in them.  Resoldering the PCBs with real solder did
the job until I sold the thing.  The audio system is similarly
affected--if the audio suddenly drops out, grab the soldering  iron.

I bought a coffee maker in about 2004 that quit working after a few
months.   Resoldering the PCB again did the trick--I still use the thing
today.

RoHS solder is a plague, particularly in hostile environments.   I've
heard that most good plumbers who work with copper pipe, hide a spool of
50-50 in the bottom of their toolboxes, just in case. (50-50 has a wide
"plastic" range and can be "tooled" to fill gaps.)

Brass musical instruments are now assembled with RoHS solder.  It's not
unusual to find that the only thing holding some parts together is the
lacquer finish--the solder has long since let go.

--Chuck




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