Hi all,
I know this is dangerous territory and got me into lots of trouble before, but
it does seem to me from recent postings on the forums, magazine articles and
videos etc that many people make life extremely difficult for themselves and
make the process a lot harder than it need be.
Perhaps this is what puts a lot of people off attempting to work with SMD
components, yet many of those who do pluck up the courage, soon wonder what all
the fuss and un-necessary concern was about. I regularly get emails from
builders expressing those comments.
You see all sorts of recommendations using toothpicks, purpose made jigs or even
two soldering irons! I can only assume the purpose of these is to try and hold
the component in place using one hand, whilst attempting to hold the soldering
iron and solder in the other, unless the human race has evolved to have more
than 2 hands, this seems an extremely difficult process!
There is a far simpler method, simply invest in a decent fine pair of tweezers.
Ok, the odd component goes pinging off, but that is true of any method of
handling SMD components!
The technique is straight forward, for passive components, resistors or
capacitors etc, simply tin one of the PCB pads, then use the tweezers to hold
the component (across the sides, not the end terminations), heat the PCB pad and
position the component. Reheat again if you need to reposition it, then allow it
to cool for a few seconds, solder the other end properly, and then go back to
the first joint and remake it if necessary.
If you find that in making the second joint, the first joint melts and the
component moves, then you are applying too much heat or taking far too long to
make the joint.
For ICs, adopt the same approach, tin one corner pad, then heat the pad and
position the IC, reheat if needed to align the pins to the pads, then solder the
opposite diagonal corner pin. Once held in position, solder the rest of the
pins.
For the ICs, initially do not worry about any solder bridges, once all pins are
soldered, use solder wick (de-soldering braid) to clear off any bridges. Always
work away from the IC body. If you work parallel to the IC, you run the risk of
moving pins sideways and possibly damaging the PCB pads.
Working with SMD components is really a very simple technique once learned and
practised.
I appreciate many learn their own techniques, there is no wrong or right way,
just some that are a lot simpler particularly when beginning. Learned that from
working with SMD components both professionally and as a ham for close on 20
years.
73, Bob G8VOI