Sat Feb 26 23:04:19 EST 2011

Soldering SOIC

Valt reuze mee!

It's not such a big deal.  Up to now my shaky hands have only
attempted DIP soldering.  However, for a contract job I was not able
to find DIP components for prototyping, so I had to get over my SMD

1. Dead-bug + AWG30 kynar wire wriap wire.

   Because I had no boards at all, this is what I tried first.  The
   soldering by itself wasn't so hard: just make sure there is a bit
   of solder on the iron and touch the wire and pin.  Getting the wire
   and pin to sit still is another matter.  A 2-arm helping hand is
   what works well here.

2. SOIC -> DIP adapter.

   I followed the advice from many tutorials online: put a good amount
   of flux on the pads (I use a nail polish bottle & brush) and place
   the component on the pads.  The flux will make it stick a bit, but
   you can still move it around.  Solder one pin on one corner.  I had
   to press the chip down to make sure it didn't slide, as my shaky
   fingers would push it out of place when I hit the side.  If it
   doesn't move any more, solder the opposite corner.  Be very careful
   not to bump the chip causing misalignment.  Once two corners are
   fixed, just add some flux on the pins, put some solder on the tip
   (I'm using a slanted flat tip) and heat the pins one by one,
   boiling the flux.

I don't think I'll be using the dead-bug style again.  While
straightforward, it is a lot of work stripping & aligning wires, and
the result is fragile.  Small adaptor boards are cheap on ebay.