Lpc2000

I always wanted to try SMD for the longest time but was always afraid
to even attempt it.  I knew there was no way I would be able to hand
solder them, and the whole solder paste and toaster oven thing just
seemed like such a hassle.  Then I took a contract job with a small
robotics company and my preconceptions were smashed.

They had a technician there that could solder fine pitch packages in a
few seconds.  Half of that time was lining the package up, the second
half was soldering.  I couldnt believe it, he was so fast, and he was
using tools that I already had.  He was like a machine.

I spent about 30 minutes with him and he showed me the tricks.  Its
simple. I will try and talk you through the steps I use.

Before you even start, you have to have a couple tools.  Most people
need some sort of magnification.  I cant afford a nice binocular
setup, so I just use one of those lenses that is on an arm and you
swing it down in front of you. Something like this,
http://www.hmcelectronics.com/cgi-bin/scripts/product/9360-0008/. 
This one is expensive, but if you go to a sewing shop or a hobby shop
you should be able to find one much cheaper.  The next thing you need
is a fine soldering tip, hoof tips are not necessary.  I use a bent
.016" tip from Weller.  You will also need solder, not the kind you
get at Radio Shack.  Radio Shack's solder is way to thick and you
always end up using much more than you need.  I use
http://www.hmcelectronics.com/cgi-bin/scripts/product/4800-0061/.  Its
.025" diameter with a water soluble flux core.  Next is flux.  You
will DEFINITELY need flux.  Flux is the only reason you will be able
to solder these packages.  I use a flux that matches the properties of
my solder,
http://www.hmcelectronics.com/cgi-bin/scripts/product/4800-0032/.  You
dont have to buy it by the gallon, so its not as expensive as it
seems.  The solder and flux are organic water soluble substances, so
after you do all your work, you have to wash the board off.  I just
run it under warm water and use a mild dish soap.

Now you are ready to start.  First step is clean your board to get rid
of any oils.  I just wipe it down with alcohol.  Then place your part,
just work each side a little at a time and before you know it, it will
be lined up on the pads.  I found that using some fine tipped curved
tweezers really makes it easier.  I just push the pins ever so gently.
 Now hose the part down with flux, dont be afraid, you cant use too
much (please use proper ventilation, solders and fluxes contain
poisons).  With a clean soldering iron tip gently press the solder to
the tip and transfer as little as you possibly can.  If you do too
much, just clean your iron and do it again.  Now just place the iron
tip on some pins, careful not to move the package and do not worry
about bridging the pins.  You are only trying to anchor the part, dont
try to spread the solder.  Repeat the process for some pins on the
other side of the package.  Now your part is firmly planted to the
board in the correct location.

Its easy now, just put a tiny bit of solder on your iron and run it
along the a row of pins.  Dont worry about bridging.  You will see the
the solder will follow your iron up and down the pins, gently coating
the pins with solder, its like magic.  If the solder is not following
your iron, you need more flux; throw some on.  Until you learn how
much solder to put on your iron, you are going to have too much and
you are going to have pins bridged.  Relax, its no big deal.  Just
clean your iron, add more flux if you need it and run the tip up and
down the row again.  Repeat this, clean and run step, a couple times
and you will have picked up the excess solder.  Now, to fix the
bridges, just gently swipe the pins quickly with the iron in an
outward motion, away from the package.  Start at the package and move
to the tips of the pins.  Dont run the iron up and down the pins like
before, the motion you want is perpendicular to that.  Now, it should
only take a couple times to remove the bridges.  If its not working,
you still have too much solder.  Clean your iron, add flux and get rid
of some solder like described earlier.

Do that for each row of pins on your package and your done.  Wash the
board and Bobs your uncle.  You are now an expert and you can take
your hobbying to a whole new level.  Bonus, you can charge your
friends a couple bucks to assemble for them.

It sounds much worse than it is.  You only need to see it once to
realize how easy it truly is.  If you are going to do this kind of
work I would recommend a hot air station.  Its technically not
necessary, but it will save you a bunch of headaches and time when you
solder the part on backwards or whatever other boneheaded mistake you
make.  They really arent that expensive anymore, you can pick up some
pretty cheap knock offs.  Heres on for $130, its Hakko knock off,
http://www.madelltech.com/M3-4.html.  There are cheaper ones out there.

As far as buying carriers boards to mount chips, I would recommend
making your own.  Use www.BatchPCB.com to order your very low run PCBs
(read: 1 or 2 boards), its run by the guys from sparkfun.com.  They
charge $2.50 sq/in with a $10 setup fee.  So you could make your
LPC2148 carrier board for half the price and you could even add room
for supporting components.

If none of this makes sense let me know I will try to do a better job.
 Hope it helps someone.

Vern