DaveC said:
Thus spake Nico Coesel:
Nico,
I know very little about this topic, other than soldering regular pcbs
(non-SMD).
If you wouldn't mind, would you explain what you mean about why you need
special tips or tools if pcb has components on both sides? And what are your
own tricks?
Pace sells special tips for removing ICs in surface mounted packages.
They also have a tweezer like soldering iron (in fact 2 irons in one)
with which you can solder both joints of SMT resistors and capacitors
at once.
For soldering fine pitch I use a hollow tip (which is available from
any major soldering iron manufacturor). It takes some practice, but it
is manageble.
I remove fine pitch chips from epoxy (FR4) PCBs by heating the PCB
-carefully- with a paint stripper. This is non-destructive for the
component.
Desoldering fine pitch chips on a board with componentes on both sides
is more tricky (and destructive for the component) since the paint
stripper method won't work. I run a enamel copper wire underneath the
pins. Next I attach the wire to a component or via somewhere on the
board. Finally I heat the pads one by one and gently pull the pins
from the pads by pulling the copper wire. This method puts very little
strain on the pads of the PCB so it can also be used on paper based
PCBs. However, all the pins on the package get bend.