On 9/4/06, Alan B. Pearce <A.B.Pearce@rl.ac.uk> wrote:
> >Is hot air capability mostly a desoldering aid?
>
> Essentially Yes.
>
> >Is it something I actually need to do limited work with
> >SMDs? If I really do need hot air to effectively work
> >with the larger SMDs then I'll (reluctantly) consider a
> >more expensive solution.
>
> Well, I guess the answer to that depends on how many ICs you intend to
> remove. That is the major area where hot air is useful. Even for an SO-8 IC,
> hot air is the easiest way to remove the chip.
>
> The alternative is to unsolder each lead individually and lift it up with a
> fine scalpel blade, so it is clear of the pad, while you do the next one ...
> and so on until you have done them all. This can get extremely tedious when
> doing larger chips. Using hot air to heat all the pins at once makes the job
> a lot easier.
>

There is a better alternative than lifting pins individually:  Make a
large solder blob that covers all the pins, then hold the board at an
angle and slide the iron around the pins until the solder is molten on
all of them at the same time, at which time the chip falls off the
board.  Clean up the board with desoldering braid, and the chip with
flux.  This method is faster and less likely to damage the chip or the
board.  But hot air is best.

Regards,
Mark
markrages@gmail
-- 
You think that it is a secret, but it never has been one.
  - fortune cookie
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist