[arm-allstar] Soldering to USB FOBs

[David McGough]

Yes, I agree that it's not that difficult...The main thing is experience,
technique used and not getting in a hurry. (and I have to remember that
long ago I did a lot of assembly-line surface mount fab work).

The soldering tip I'm using is HUGE--the same tip I use to solder PL-259
plugs!!! But, the soldering station is a quality Weller digital
temperature controlled model. I -highly- recommend biting the bullet and 
getting a good soldering station!

Here are some high-res photos of my setup and the iron tip I use.  For
beginners, I recommend practicing on junked computer boards as a place to
experiment! For these USB FOBs, push the wire into position under the
CM108 pins and apply a small amount of solder to the exposed wire leads.
Then bend the leads next to the chip pins and quickly tack them to the
chip with the tip of the iron...Finally, once soldered, you can gently
push the teflon insulation snugly against the connection from the opposite
end, just for added insurance against any intermittant shorting under the
chip when the leads are moved during attachment to the remaining interface 
circuitry.

See:

https://hamvoip.org/photos/P1040020.JPG
https://hamvoip.org/photos/P1040026.JPG
https://hamvoip.org/photos/P1040017.JPG

Here is the wire I'm using. It's 30 gauge, Kynar, teflon insulated 
wire-wrap wire:   http://www.ebay.com/itm/200406828268


73, David KB4FXC


On Mon, 11 Jan 2016, Dan Bates wrote:

> The trick to tacking the wires on the FOB pins is to use wire-wrap wire and
> a very small tip iron. 
> Strip no more than about 1/16" of insulation off of the wire and bend it
> into and "L".  
> Pre-tin the wire, hold it to the side of the pin and just touch the tip of
> the iron to the pin very quickly.  It should stick.  I then use superglue to
> hold the wires to the circuit board before splicing to a flat ribbon cable
> which I then tie wrap to the FOB body.  I thread the flat ribbon cable
> through the hole left from removing the buttons.
> http://www.n5tm.com/wp-content/uploads/2016/01/RPI2_FOB-e1452553647990.jpg
> 
> 
>  I don't have the best vision, but have had no trouble modifying them.
> 
> Dan n5tm
>