# How do I solder tiny leads?



## gearbox (Sep 4, 2007)

I have a project I would like to use a Rebel emitter on, but I don't know how I can manage soldering onto such a small area with an average Weller pencil.
Tips or advice?


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## frenzee (Sep 4, 2007)

It absolutely can be done. Buy a needle nose solder tip and use a magnifying glass with a flexible neck and stationary base so you can see better. Secure the rebel with masking tape to a solid surface with the contacts exposed. Frist coat the rebel's contacts with solder flux, dip the solder gun tip in the flux and clean it off with a sponge or paper towel, melt a tiny amount of solder onto the solder tip and wet the contacts on the rebel. Do the same to the tips of the wire you intend to use making sure that there is a tiny blob of solder at the end of the wire. Place the wire on the contact and apply the solder gun for a couple of seconds until it melts onto the contact. I've done at least 20 rebels so far and it works quite well.


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## jeffosborne (Sep 4, 2007)

Hi gearbox! I have soldered a few dozen rebel LED's with good results. Usually I have already epoxyed the rebel to the heatsink before I solder wires to it. Here's my method:
1. scrape the thin enamel-like cover off of the traces on the top side, use the tip of an exacto knife. Dont scrape too hard, but keep scraping lightly until the copper traces look real shiny.
2. Be sure to have a wet sponge or paper towel to wipe the end of the iron. Any extra solder on the tip will not be helpful. After wiping clean, apply a very small amount of solder to the tip. 
3. Put the tip of the iron, with solder just appied, onto one of the rebel copper traces, and immediately add a little more solder as close as possible to the junction of the iron and the copper trace. Remove the iron. The copper trace should now have a small amount of solder on it. This is called 'pre-tinning' the trace.
4. Use a small gauge wire. I use 28 gauge for short runs, and 24 gauge for runs up to 60'. Larger gauge wire is bad because it can rip the trace right off of the LED if you bend the wire too much. Smaller gauge wires will not stress the solder connection. Pre-tin the wire end by applying a small amount of solder to it.
5. Carefully clean the end of the iron again, and apply a small amount of solder to the tip. Put the pre-tinned wire lead on the rebel's copper trace, and apply the iron. No need to add solder at this point, just melt what you have already applied.
Here's a photo where I used 20 gauge wire from my battery pack to attach to the rebels, and 24 gauge telephone-type wire to connect two LED's in series. The big 20 gauge wires gave my trouble, breaking away from the contact. I had to re-solder them several times until the project was complete.






What are you going to do with your rebel LED?

Jeff O.


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## dat2zip (Sep 5, 2007)

I made thin PCBs to deal with the Rebel LED. You can solder on the Rebel onto the thin PCB using solder paste or pre-solder the pads and then reflow the Rebel onto the soldered pads. Either way is possible with a standard soldering iron.

The thermal pad is via'd to the bottomside for great thermal relief and there are side connections to connect the LED+ and LED- wires. The board diameter is 10mm.

On the left is the top side view with a Rebel LED mounted. The right is the bottomside view of the thin PCB and the SMT resistor is a 0603 for reference.





The thin PCB is approximately 0.2mm thick and can be cut with a pair of scissors if you need to make it smaller. Once the Rebel is solder down the thin PCB is then thermally glued to a heat sink.

If you are interested in trying them out they are available here.

Wayne


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## gearbox (Sep 6, 2007)

Thanks guys.
I'm planning out an LED conversion for my SF E2. I have a whole bunch of lights and this one just doesn't get used now. I'd like to throw in an LED for long runtimes without modification to the light itself.


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