[Coco] Run of RGB2VGA boards

[Steven Hirsch]

On Mon, 14 Sep 2015, Zippster wrote:

> You just have to touch the tip of the soldering iron to your solder to 
> get a small amount on the tip.  It doesn’t take much.  The flux applied 
> to the pins before hand keeps the solder from getting “sticky”, and the 
> surface tension of the molten metal pulls the excess off of the pins.

> It’s actually surprisingly easy once you get used to it.  The hardest 
> part ends up being aligning the chip before tacking the corners.  I 
> found it nerve-wracking and frustrating at first, going with my first 
> instinct, which was to try and precision solder individual pins.  But 
> after learning drag-soldering it’s just as easy (or even easier) than 
> through-hole pin-for-pin.

I have seen special tips with a concave area designed for "drag 
soldering".  Are those worthwhile?

Also, what brand and type of flux do you use?

I invested about $400 in a BlackJack hot-air reflow station about five 
years ago, but never had much luck with that either.  The YouTube videos 
always make it look so simple...  Other people slather on the solder 
paste, wave the tool over it and - bingo! - perfect solder flow.  When I 
do it, the solder ends up being blown underneath the chip in tiny little 
globs where it shorts out everything.  I'm guessing it's a matter of 
finding exactly the right combination of temperature and air-flow, but 
never can seem to dial it in.  At least part of my problem is a fear of 
damaging the parts and / or board by overheating.  But, I'm getting the 
impression that modern VLSI semiconductor components are not all that 
heat-sensitive.

Any, maybe it's a generational thing?  I grew up with a soldering iron in 
my hand and never had any issues with "traditional" soldering.  SMD just 
seems to be my nemesis.




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