[sdiy] Naive SMTremoval question

[The Old Crow]

  With the right tools, yes.  You need a hot air gun that has a small 
nozzle, adjustable flow rate and is temperature-controlled.  Additionally, 
you need some fine wire that you can slip between the chip and a row of 
pins to help lift the legs as the hot air metls the solder.  Once the old 
chip is freed, you need to clean the SMT pads yet leave a little solder so 
the new part will have something to adhere to when it is all done.

  Another tactic is to use a dremel cutting disc to _carfully_ saw through 
the pins, then desolder the pins.

  Soldering the new part is probably best done in a toaster oven, using a 
little solder paste, a toothpick and a lot of patience.  Once the paste is 
on the pads, and the part is on the paste/pads, a 3 to 4-minute bake at 
420F usually solders things fine.  If any parts (electrolytic caps) have a 
plastic jacket, remove them and re-solder them after the bake.

Crow
/**/

On Tue, 12 Aug 2003, Peter Grenader wrote:

> Kids,
> 
> Can an fine-pitch SMT component with a lot of leads, like a processor, be
> replaced while its on a board  populated with (many) non-SMT parts?