Cree XP-E / XP-G hand soldering?

[Lightsman]

I'd like to know if anybody has tried to remove a XP-E / XP-G manualy (i.e. soldering station) and replaced the LED (i.e. XP-E changed to XP-G). I'm asking since Cree does not recommend hand soldering at all. Since I do not have a reflow soldering station I'd like to know if it is possible to do it by hand.


I'm skilled in soldering and I could use a Weller soldering station with build in hot air blower.

Any experience...?

 

[PCC]

I messed up soldering to the tiny pad on a star board once and thought I had fried the XP-G. That's because I could not get the emitter to light up using my voltage meter set to test diodes after the solder job. Most LEDs would glow dimly when tested this way and this one didn't. I then held the star board in a pair of forecepts, blobbed some solder onto the iron tip and applied this to the top of the star with the emitter on the bottom. The LED fell off after a few seconds. I then tested the emitter directly on the contacts and it worked so I reversed the process and soldered it back onto the bad board after I cleaned it up. It's now working quite nicely in my bike light.

The XP series LEDs are tiny. It's possible to solder wires directly to the contact pads like you would to an XR-E but it would be extremely difficult to do. The contacts are about 0.5mm X 3mm each and doesn't leave much room for the thermal pad in between.

 

[^Gurthang]

Though small you can reflow solder and XPG to an XP series MPCB using a soldering iron.

The trick I've used is a hemostat. I pre-tin the board [star] w/ solder, use only a tiny bit of solder for the pads, too much solder will reduce the heatsinking and risk frying the emitter.
Then clamp the hemostat so the board is level. I use fine tweezers to hold the emitter by the edges.
Apply the iron to the bottom of the star. Once the solder is hot I carefully place the emitter and remove the iron.
A quick touch w/ a damp rag on the bottom of the star sets everything in place. If you mess up or don't like the result; just invert the star and apply heat, then a quick tap will free the emitter.

BTW, its best if you practice this a few times w/ a junk emitter so you get the hang of "reflow" soldering.....

Second tip: use a bit of flux on the emitter. This aids soldering speed and gives a better joint.

 

[Lightsman]

Thanks for you suggestions. I ordered a few XP-G LEDs and try to change the LED... no risk ... no fun! :laughing: