Has anyone tried and been successful at reflowing emitters with the MCPCB in place with either 2 soldering irons or a hot air station….this could save a lot of time if possible….Just don’t know if this method would concentrate too much heat on the LED itself rather than the MCPCB solder pads resulting in burned up emitter. Worth a try? Or doomed to fail?
Not practical. You would pretty much have to get the whole light up to 200C.
How would it save any time?
By not having to Desolder the led wires? They’re gonna Desolder before the LED does… Plus it’s hard to work down in the head of a light. Plus how are you gonna hold 2 soldering tools and manipulate the old led out and the new led in place with only 2 hands? Plus as you mention you’ll be cooking the led, have you read the thread about better led attachment methods? Led reflow temp is super important, even a little to hot just one time will permanately degrade output.
Just pull the mcpcb and do it a normal way (hot plate or hot air)!
Using hot air is possible in some scenarios but like C_K mentioned, temperature and temperature profile are important considerations.
I made it with an armytek partner, the mcpcb is epoxied to the light so the only way to reflow a led was hot air + soldering iron touching the mcpcb
I have once soldered a MCPCB to a pill and then reflowed the LEDs onto the MCPCB afterwards. It was more difficult than expected. that would also be one of the unique use cases where this kind of strategy might be required.
If you put the LEDs onto the MCPCB first and then solder that into a pill… might get too hot for the LEDs.