Personally, I'd do the DDS chip first, before the resistors and
capacitors. One of the tricks I use is to clean the IC pins with rubbing
Alcohol after soldering and removing shorts.

Then, I apply a hot air gun, SLOWLY bringing the temperature up on the
pins of the IC. I try to get to barely melting the solder, but not burning
the main board. A slow application allows the IC to heat up gradually.

This tends to remove the hairline solder bridges and clean up between the
pins of the IC. Since the main DDS chip is the only part on the board, I
don't have to worry about heating up and blowing the resistors and
capacitors clean off the board !!!

I can, and have, used this same method on a completely assembled board,
but I have to pay close attention to the small parts, the tend to want to
blow away. In that case, I build a heat shield with tin foil and I press
it down on the board all around the IC I want to solder flow and that
usually keeps the other parts on the board where I want them.


This all takes a delicate touch, it's pretty easy to get things too hot,
but it does provide nice and clean solder joints.


Jim Pennell
N6BIU


--

23:10 Pacific Time Zone
Dec 28 2006

International Time
07:10 UTC
29.12.2006