Soldering SMD's

[Buck Buchanan]

Hi all,
 
> What's the minimum configuration needed to solder SMD's?
> How do you do it?
> I mean do you need special soldering tips or stuff or is it possible to
> use a hot air blower in a wave-soldering fashion? As you can see, I'm
> totally lost with the subject ;)

Just my opinion - your milage may vary:

Start with 2 soldering irons both with the sharpest tips you can find. 
For 0402 and 0602 sized parts, even the smallest Wellar and similar tips
start getting a little big and expensive stuff like Metcal starts to
look good (though it won't surprise me to see Weller, ungar, etc start
coming out w/sharper tips for this stuff - maybe they already have). 
For 0805 and larger the sharpest Weller, Ungar, etc are probably fine. 
The they make all kinds of funky tips for SMT work but personally I
think they're mostly a waste of time and money - two irons w/basic tips
is better than one iron with all the fancies (IMO).

Visual aid: stereo microscope with a long focal length for 0402 and 0603
- pretty much gotta have it *if* you really want to do a good job. 
These aren't super magnification things - maybe 2-10x. 0603...
microscope is ideal but *might* be ok w/Luxo lamp magnifier.  0805,
1206, and up luxo lamp is fine probably.  Most of the good scopes for
SMT work seem to start around $1,500.  2 grand get's you a nice one. 
This is probably the most expensive invenstment.

Solder - ultra thin.  Bottle of flux - the goop or no clean, I prefer
no-clean for SMT.  Excellite or other good tweezers - one pair bent, one
straight.  Small/thin solder braid.  Leave the sucker in the tool box. 
Wet sponge (if you're not into a clean tip now, you will be). Alcohol
and swabs.  Unless you need to remove large package ICs in one piece, RF
modules (like VCOs, duplexors, etc), RF shields, etc, you definately DO
NOT need a hot air device of any kind.

Removing a part (say an 0603 sized cap): pick it up from both sides with
the two irons.  Throw it in the trash (ok in real life you can re-use
parts if you're clever about it but you have to be real aware of
potential part damage).

Installing a part (same cap):  clean one pad w/solder braid so there's
no solder on it at all, then clean w/q-tip and alchohol.  The other pad
should just have a little solder bump on it and clean as well.  put
goopy flux down and then the part or the part first and drench w/no
clean flux.  Now hold the part straight putting a light pressure down on
it.  Touch the solder end with a CLEAN solder tip.  The part should sink
onto the pad and held at soldered end.  Solder the other end.  You will
learn to move quick and once you get good at it, it's really pretty darn
easy.

To install ICs:  clean all solder off pads except for one on the end
with a little solder bump.  W/plenty of flux hold part on top of pads
and touch the top of the pin that's on the solder bump.  Again, this
will sink in.  Tak down another pin on the other side and then work
around.  Don't worry about solder bridges - a little braid action will
remove the bridge and leave the part well soldered.  Again LOTS OF
FLUX.  w/the no clean stuff I sometimes solder under water (flux) even.

For synth DIY stuff I'd reccomend 0805 or larger SMT components.  SMT
phobia is common but it's all pretty easy once you get the hang of it. 
I actually prefer working on SMT stuff to through hole - you can do some
pretty neato stuff.  Weird hacks and what not are a lot easier than
you'd think with SMT.  

Take some old computer or dead cell phone boards and practice.

Have fun,

Buck