home | list info | list archive | date index | thread index

Re: [OCLUG-Tech] anyone local do really fine soldering?

On 11-12-13 07:57 AM, Richard Guy Briggs wrote:
On Tue, Dec 13, 2011 at 04:40:31AM -0500, Robert P. J. Day wrote:
   just got my new pandaboard ES:

http://pandaboard.org/content/resources/references

and as you can see, there are a number of expansion options on the
board screaming for connectors to be attached.  i don't have that kind
of equipment or skill -- anyone around here capable of doing that?
I'm able to do this with inexpensive soldering equipment, augmenting my
35 year-old skills and practice with extra flux and a good magnifier.

Here is an excellent tutorial that gave me the information and
confidence to start doing it myself.

	http://www.youtube.com/watch?v=3NN7UGWYmBY


FWIW:

I've been doing this stuff for eons as well - but you don't want to make your first attempts on something you value. Best results happen after you practice on old stuff for a little while. There is no end of junk boards out there. I've had my son practice on old junk and saved a whole lot of good things from destruction. Safety glasses and a directed muffin fan blowing gasses away from you should be mandatory. Soldering gasses and the byproducts of heating lead & flux shouldn't find their way into your lungs.

Surface mount stuff is a lot more complex - in the build process, solder/flux paste mixture is screened on the board and the connector/device is placed on top of it. It then goes in an reflow oven and the device melts "down" into the solder and attaches. This way, all contacts are attached in one pass with even mechanical and electrical connection. Doing them one at a time generally results in uneven contact and make poor electrical connections probable. A small gas hand torch from Lee Valley can generate better heat than an iron - and a good iron is waay better than a cheap one.

Biggest problem with hand soldering is cold solder joints - joints that look good but the electrical contact is compromised by fractures you can't see - but resistance is measurable between the pin and pad. By manually heating the single joints one at a time, consistent joints are hard to get without overtemps and undertemps due to extended or inadequate heating time.

There is a small ISO soldering shop out in Carleton Place (actually three of them) that can do this at a reasonable price. Call Dan Angell at HiQA and see if he can handle a one-off soldering job - he's probably do it for a few bucks or a free lunch with a beer.

--
Bill Strosberg