Erik Christiansen wrote:
One day I must try the upturned (clothes) iron method, where the PCB is
slid onto the hot iron, and off again when the solder has reflowed,
after a few seconds. It's only going to work for the one side, I guess,
but so far I've only put a few componenets on the back. They could be
hand soldered afterwards. (And now, more easily. :-)
The best method I've found, from a site I can't remember off the top of
my head, is to use a cheapo ($20) electric skillet. Place the board in
the skillet, turn the heat on, and wait for it to reflow. Get one with
an appropriate cover (which I did), and you can put a fume extraction
system on it (which I have half done). The fumes aren't so nice, though
I don't get the impression there's anything particularly fatal in there.
However, make certain any cover you put over the thing is *clear*, so
you can actually see when it reflows <g>
A specific note about "after a few seconds": if you were able to heat it
up that fast (which a clothes iron can't anyway, in ambient air), you'd
literally cook off the chips. Reflow profiles generally specify
anywhere from 2 to 5 minutes of warmup at a specific rate, or you risk
the moisture in the chip literally blowing it to pieces. I've found the
cheap skillet I have takes about 2.5min from cold for the tiny boards
I've done so far, which is just about perfect.
I like the idea of most of the heat reaching the solder before the
chips.
This is the main reason that the site I found the idea on came up with
the idea. They were soldering surface-mount USB connectors with a
toaster oven, and the connectors' plastic was melting before the solder
paste did. Whoops.
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