> > I use a Metcal soldering iron for that and are very satisfied with it.
> Metcal soldering iron (plus a bunch of different tips) is by far the best
> tool to do any prototyping SMT work (well, except BGA). A while ago there
> was a discussion on GNUSIMM mailing list and I posted a message about it but
> nobody seemed interested...
I like the Metcal also for "normal" soldering. By far the best I have
used so far.
> > The tip is shaped as if you'd write with a pencil on sanding paper.
> You probably talk about "hoof" tip. It is designed specifically to be used
> with "dragging" technique.
Yes, it is. My point was mainly that you *don't* need a needle-tip-thin
soldering tip. It works better with a thicker one.
> > Then I found out that the tin on the pads is already sufficient.
> Actually the rule of thumb is:
> - fill 100% of the tip with solder for 100 mil pitch
> - fill 50% of the tip with solder for 50 mil pitch
> - fill 25% of the tip with solder for 25 mil pitch
> - fill 0% of the tip with solder for <25 mil pitch. There is enough solder
> on the land and the pin.
Aha! We have 25 mil pitch, so my 0% is marginally working.
> > I never had a bridge between pins this way.
> I was less fortunate (or less handy) but most the time it worked fine.
I guess I don't have problems because I use too little tin anyway :-)
(according to your rules)
> > No matter which way you go, the pads Protel has per default are
> > sub-optimal (at least for the chip I'm using). It's a lot easier
> > to solder when you move the pads slightly outwards:
> Well, I would be a bit cautious here. If it works fine with "dragging"
> technique it does not necessarily mean that it will work fine for
> production. Any experts on PCB yields here? Can anybody comment?
We'll soon ship the boards to be populated/soldered automatically.
Then I'll see.
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