Homebrew PCBs

----- Original Message ----- 
From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, August 18, 2007 9:37 AM
Subject: Re: [Homebrew_PCBs] Re: 0.5mm pitch breakout board?


>I ordered the sharpest pencil point they make, to try if it is better
> than a larger tip for QFN and other small stuff.
> It isn't.
> I end up drag soldering all the same, and the thin tip is a nightmare
> if you try to solder even small pins to big copper areas.
> With the slightly rounded tip drag soldering works whatever way you
> move the iron. With the sharp pencil tip i find it is better to angle
> the tip and push it so that the point is leading. If you let the point
> trail it makes more solder bridges. My theory is the trailing fillet
> in the gap between tip and PCB aids in cleaning bridges, with the
> sharp tip trailing there is no fillet. With larger  rounded chisel
> type tips there is always a fillet whichever way you angle the iron.
>
> So you can drag solder with a sharp pencil tip, but there doesn't
> actually seem to be any advantage over a slightly larger more
> universal tip.
>
> I plan to buy the power well tip some day, and see if it is better in some 
> way.
> (It's a little like the hoof from metcal)

The mini-hoof doesn't work very well for drag soldering with QFN, I use a 
rounded tip as well for that, with plenty of gel flux. The mini-hoof is very 
good on fine-pitch QFPs, of course.

Leon