How to reflow solder an LED emitter on a PCB or MCPCB.

Hi all,

I have decided its time to do an instructional video series. “Flashlight hax” will be the theme for most of it. I thought re-flowing would be a good place to start since I get a lot of questions about it. Hope you enjoy.


If this tutorial helped you please click “like” on the video. If you enjoyed it and would like to get a notification when the next video on the series comes up you can subscribe.
Here is a thread on how to use a soldering iron.

Great video. I wish there had been more of this type of “how to” videos when I was a beginner modder. Thank god Old Lumens was here for us, or I would have been lost.

Well made! Good resource. I wish I had seen this when I did my first reflow. :cry:

Thanks vob. Nice video.

Wow, this is a great video ’vestureofblood’!!!
It answers every question I had about this subject as well as took the “mystery” out of it. I actually believe I can do this now without a problem.
Thank you for sharing this……… :slight_smile:

EDIT: May I suggest this thread be made a “STICKY”…. The info is priceless as far as I am concerned. :slight_smile:

Very well done! You could be an educator. I am not a model so this was really an eye opener for me.


Good video, thanks for this. Also big thanks for the work you have uploaded on Oshpark.

Good Stuff.

Nice video …
you need to start doing infomercials.



See how large a letter I have written unto you with mine own hand

Thanks for video. It was very useful.

Wow! This just came on time!

I’m planning on reflowing 4 3’5×3’5mm emitters on an XHP70 board. I see you “tap” the emitters to remove excess solder but, I wonder what will happen upon tapping over the dome of each one of the emitters on such a 2×2 array. :confused:


P.S.: Great tutorial.

NICE thanks!

Thank you all for the comments, I appreciate them.

I know you can do it.

“What one man can do, another can do”

- Anthony Hopkins - in some movie I forgot the name of.

Maybe if Convoy, Surefire, or Maglite ever needs a guy I will get the job :slight_smile:

Thats a pretty ambitious reflow for anybody. I’ve never tried it. I suppose if you have a problem with them squabbling around when you tap something you could do is this. Once you have them in place you can take something with a flat and set it on them. A glass lens should be heavy enough to push them down and you could still see if they had been moved out of place. I have done that a couple times. You just put the lens in place ( I used a borofloat maglite lens) and turn off your heat.

Once you get it done maybe you can shoot us a pic or two.

Thanks, very helpful.

Whew! And I was just thingking in assembling a mixture of emitters like a “XP-L HI”/“219B” and “219B/XP-L HI” plaid fashion … DERP!

Cheers :partying_face:

Better get this one to the top again in time for the made from scratch contest :slight_smile:

A lot off effort from vestureofblood. Very nice and educational video. :+1:

I still use Old Lumens bench vise - soldering iron method and I found that as a best method for me (btw it is also very safe and regulated through regulated soldering station)

Worth to mention that there are emitters which will not automatically suck into MCPB and they require steady hand, eagle eyes and firmly pressed MCPCB to properly set up emitter on tray :slight_smile:

So if you have emitter on MCPCB that refuses to suck it Old Lumens method is only one that will do and especially if you want to tap and hold emitter until it cures to push excess solder and to make as thin layer of solder between it and trays.

This! XPE2 simmilar ones do that often, they are just too light to push the extra solder aside

Something else that is important and worth mentioning: sometimes the emitter + pad and the core pad could solder toghether yet the emitter will work( xml, xpl, xpg est).

It will work even if you connect the proper driver for testing outside the flashlight, but then inserted in the host the MCPCB will contact the host body and ofc this will cause a short connection.

Thats valid for DTP MCPCBs, non dtp in this case wont suffer that issue yet the emitter core isnt electricaly neutral: sometimes it could affect driver memory mode and/or correct driver modes

Ya, doing small emitters is the hardest. For me either setting a piece of glass on them to weight them down (like when doing a triple) or a very quick “tap”, hard and fast enough to eject the extra solder like a projectile is about the best way.


My first reflow guys, done with helping hands, standard solder wire and a cigarette lighter. Toasty! LOL!

Cheers ^:)