[Coco] Run of RGB2VGA boards

[John B]

Ed,

What soldering iron do you use?

On Tue, Sep 15, 2015 at 9:15 AM, Zippster <zippster278 at gmail.com> wrote:

> I usually use a tip like this one for drag soldering.  <
> https://drive.google.com/open?id=0B1sgl615FlGnRmFEQURPLXV4emc <
> https://drive.google.com/open?id=0B1sgl615FlGnRmFEQURPLXV4emc>>
> I’ve seen ones in this shape that have the concave surface, I haven’t used
> used them, but they look like they’d
> work well except they might have a tendency to carry too much solder.
>
> I use Amtech 4300 flux in the 10cc syringes. It’s great for SMDs, and
> somewhat tacky which helps hold small parts
> in place when positioning them.  Fantastic for cleaning up through-hole
> solder joints as well.
>
> I tried the hot-air method when I first started trying SMT.  It worked ok,
> but you often have to clean things up with
> a soldering iron afterward.  Also, there's the inconvenience and mess of
> using soldering paste (which expires and
> becomes unusable).  After I found I could do everything with an iron,
> there was no contest.  I want nothing to
> do with hot-air except for removing SMD ICs and shrink tubing (which it is
> perfect for).
>
> I find that now I use only two types of tips for all my SMT and
> through-hole soldering, the type linked above,
> and a chisel tip like this <
> https://drive.google.com/open?id=0B1sgl615FlGnVmROZmE3dnlnXzA <
> https://drive.google.com/open?id=0B1sgl615FlGnVmROZmE3dnlnXzA>>
> Surprisingly, I don’t like the traditional conical type for anything
> anymore, the chisel tip gives me more control.
>
> SMT soldering is different than through-hole, which is what I was used to
> as well before getting into it.
> Mastering it basically boils down to being able to control that surface
> tension, or capillary action as Mark puts it,
> which is done through a combination of temperature, flux, shape of the tip
> and how you move it.
>
> It’s definitely worth learning, it will improve your through-hole
> soldering skills as well.
> You can do everything but BGAs with a temp controlled iron, good flux, and
> the right tip (and any needed
> magnification).
>
> - Ed
>
>
> > On Sep 15, 2015, at 6:51 AM, Steven Hirsch <snhirsch at gmail.com> wrote:
> >
> > 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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