[sdiy] solder wick?

[Scott Stites]

For surface mount IC's, we've got these heat guns that make those suckers
slide off like butter.  In lieu of that, there's a larger apparatus that has
a frame for each IC package - it fits over the IC, blasts it with
superheated air, and then has suction that lifts the IC straight up so you
don't have a chip slide across the board, stringing solder in its path.   I
had to replace several fine pitch buffer chips using one of those on a field
trip from hell a few years ago (that's what you get when your company
replaces a chip with a cheaper 'identical' chip from a different
manufacturer).  Too bad they didn't have a counterpart to the de-solderer
that would solder the new chip on (ohhh, nooo, have to do that by hand....).
Field circus, right Scott G.?

For surface mount caps and resistors, I use two soldering irons to pick the
part right off the board - like chopsticks, only two-handed.  That's when I
use solder wick - to clean the excess solder off the pads.

Jim's practice of clipping the leads of through-hole IC's is definitely the
standard means of removing them in our shop as well - saves old fragile
circuit boards, especially.

Scott


----- Original Message -----
From: harrybissell <harrybissell at prodigy.net>
To: The Peasant <epeasant at telusplanet.net>
Cc: Gene Stopp <gene at ixiacom.com>; synth <synth-diy at dropmix.xs4all.nl>
Sent: Friday, February 28, 2003 6:51 PM
Subject: Re: [sdiy] solder wick?


> Since Le Peasent  (is he related to Bob Pease ?)
> gave me such a nice intro...
>
> Boards that are wave soldered in manufacturing facilities
> need careful control of the wave chemistry... ie the LEAD
> is selectively drawn out of the bath as more boards are run.
>
> This can be judged by specific gravity of the molten metal...
> and a lead-rich alloy is added to balance the loss.
>
> Failure to do so gives a solder bath that melts at progressivly
> higher temperatures...  Now badly run facilities just turn the
> temperature up and keep going...
>
> so I tried to recover some A-B type W pots (1/2" diameter - 1/8"
> shaft - VERY nice) from a centuries old board. The soldering iron
> would not even melt the solder... adding flux and fresh solder was still
>
> a no-go.
>
> so I got the propane torch... it STILL would not let go until the board
> burst into FLAMES...
>
> Can anyone tell me what the composition of the solder pot was on the
> day that board was run ???
>
> (I figured it out AFTER much thought...   ;^)
>
> H^) harry
>
> The Peasant wrote:
>
> > > One thing that is really neat for removing parts whole is
> > > a solder pot. Good
> > > example - I used to have all the circuit boards from a
> > > 360 Systems Digital
> > > Keyboard. Loads of good parts - CEM3360's, nice trimpots,
> > > TL082's by the
> > > dozens. With a solder pot I stocked up my parts drawers
> > > in a matter of
> > > minutes. This ruins the circuit board. The fiberglass
> > > starts to come apart.
> > > Solder pots are also fun for experiments with molten
> > > metal when the boss
> > > isn't around
> >
> > I once knew someone who would salvage parts from pcbs with
> > a propane torch, just heat each area, solder side up, the
> > parts would just fall right out. This only worked for some
> > boards though, and it sure trashed them!
> >
> > Take care,
> > Doug
> > ______________________
> > The Electronic Peasant
> >
> > www.electronicpeasant.com
>
>