[hpsdr] Atlas, How do I hand solder this thing?

[Philip Covington]

On 6/19/06, Robert McGwier <rwmcgwier at comcast.net> wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> For quite some time I have taken the bull in the china shop approach
> with 100% success (and it has the benefit of appealing to my nature ;-)
> ).  Tack the corner and then get solder everywhere on the remaining pins
> for the IC (either DIP and quad leaded).  The detailing is then done
> with solder wick to remove the excess and shorts.  Inspect with
> magnification.  This beats the heck out of attempting to solder single
> leads at a time.
>
> Bob

This method works with pre-tinned boards - not sure about the gold
boards like the Janus and non-alpha Atlas:

The approach I take with the 0.5mm stuff is to tack down two corners,
then flood with flux.  There is usually enough solder on a tinned tip
and the pre-tinned board to be able to slowly drag the tip of the iron
at an angle across the pins.  The surface tension of the solder in
addition to the copious flux keeps solder bridges from happening.  I
think I dwell about 2-4 seconds per pin with the tip at an angle so it
is in contact with more than one pin at a time.  I then grab my
Pakistan-made dental pick type instrument (purchased from Newark) and
drag it lightly over each pin while looking through the microscope or
magnifier.  The tip of this pick is small enough that it can fit
between each 0.5mm pin. You can immediately see and hear if any of the
pins have not soldered.  Using this method I have not had to remove
bridges with solder wick.   Like I said, not sure how this is going to
work with the gold plate boards...

De-soldering QFPs works similarly.  I flood with flux then use the
dental pick to "lift up" the pin while applying heat from the
soldering tip.  This only takes about 1 second per pin.  I was able to
unsolder a 100 pin 0.5mm QFP in less than 2 minutes using this method.
 If you are not too wild about pulling up on the pin, the deflection
is so small that the part can be easily reused by setting it on a flat
surface and using the pick to straighten/lower any of the pins that
need it.

Of course, using SMT soldering equipment like a hot air system you
solder/unsolder these type of components too.  The reason I mention
the above methods is that they work with a minimal investment in
tools.

73 de Phil N8VB

 1150717464.0