Dave Platt wrote:
In article ,
ken scharf wrote:

Well there is good news and bad news. The bad news is that it is
impossible to solder the chip by hand without creating solder bridges.
The good news is that I did a good enough job to get the chip 99%
perfectly centered on the solder pads, and you can remove the solder
bridges with solder wick without removing the chip from the PC board.

I've seen people recommend this as the preferred hand-soldering
approach for dealing with small-pitch surface mount parts. Don't
worry about creating bridges... use a bit of liquid flux on the pins,
get a nice blob of fresh solder onto the tip of the iron, and then
just gently drag the molten solder-ball along the pins and get them
soldered to the traces. Then, go back over it with solder-wick and a
bit more liquid flux, and wick away the excess.

I did smear the pc lands under the chip with paste flux first. Not a
heavy coat, just lightly applied. It does help.
I've watched the technicians at work hand solder even finer pitch chips.
One young woman has very good close in eyesight and works without a
magnifier. She does have to clean up with the solder-wick, but makes
machine like perfect solder connections. (she makes it look EASY!)
Whats hard is doing an entire board in one sitting without getting a
visual version of writer's cramp. (eye strain)

On 2006-12-28, ken scharf wrote:
I've watched the technicians at work hand solder even finer pitch chips.
One young woman has very good close in eyesight and works without a
magnifier. She does have to clean up with the solder-wick, but makes
machine like perfect solder connections. (she makes it look EASY!)
Whats hard is doing an entire board in one sitting without getting a
visual version of writer's cramp. (eye strain)

After you've done it enough under a microscope you learn what is going
to happen and you can do a lot of it without even being able to see it,
by timing and feel. Like you said in another post, there's also the
part where you get used to how disgusting any solder joint looks under
sufficient magnification...

--
Ben Jackson AD7GD

http://www.ben.com/