Changing LEDs on a M 43 Noctigan - how to do?

plata0190 · Jan 30, 2016

Hi, What about modding leds on a flashlight? I wanna do this but have to inform well and figure out how to do without damaging something.

- Which is a better solution to solder new LEDs on the MCPCB? Heating up the board touching its girth with a soldering iron, or heating up the bottom of the board by a reflow method using a heating gun at 250-350 C°? It's safe enought as rhe main fact I'm suspecting with is that that's method may burn the bottom copper or printed circuit of the board?

- For the tin, I saw on youtube some vids where people uses a sort of grease instead the classic tin filament. What is its purpose?
How much tin have to put on or the pre existent one is enough?

That's all for the moment, please give me some suggestions. I'm a newbie in this ambit

The flashlight is the M43 noctigan, so you can see online its pics. I think that only 35x35 and 37x37 mm packages are compatible so going to replace with something with a warm tint as Cree XPG, Osram Oslon, or Lumileds TX, T

richbuff · Jan 30, 2016

Interesting. Have you looked/asked here: http://www.candlepowerforums.com/vb/forumdisplay.php?17-Homemade-and-Modified-Flashlights-Discussion

peter yetman · Jan 30, 2016

I've been researching the same thing. Try these....

http://www.candlepowerforums.com/vb...-Do-you-reflow-toaster-hot-air-or-reflow-oven

http://www.candlepowerforums.com/vb/showthread.php?360068-1st-time-doing-reflow

The grease is Soldering Paste, I think.
P

plata0190 · Jan 30, 2016

I red quikly and there are many suggestions - that's good, but before starting I wanna know exactly some particulars:
- pre existent tin is enought to solder new LEDs?
- may I use the standard filament tin or the soldering tin grease is something more aimed for MCPCBs?
- does the heat produced by the heat gun, burns on the bottom copper board? and at which distance is safer to keep it during the heating up?

keep in mind that the only one soldering iron that I own is a cheap 40W (10$) and is not able to desold even the +/- wires blob, I think due to the dissipating heat from the pad board.
I bought this heat gun, let me know if is good for doing this work?
http://www.amazon.it/gp/product/B00NM8IEXW/

Thank you!

plata0190 · Jan 31, 2016

last question:
- heating up directly on the bottom copper MCPCB witht the heat gun will mark it with some burns? I think is inevitably due to the oxigen and the high temp... what about this?
- May I keep the thermal grease under the board to preserv it from burning marks or the thrmal grease won't be able to compete with so much heat?
- May I use some cleaning flux?
- The pre existent soldering tin/grease is good enought for the new LED or may I use some more from my filament tin?

plata0190 · Feb 2, 2016

plata0190 · Feb 3, 2016

Hi, I'm encountering difficulties to desold tin blob on + and - MCPCB wires. It's about 4mm round and using both a gun desoldering (40W of power consuption + a pencil 30W). I kept them on the blob for more than 40 seconds but it won't be desolded. I think that's because the MCPCB dissipate immediately the heat from the blob. I tried to accompanish the operation with a hair phon, or detached for a while the borad from the flashlight base.

What can do? is an alternative or have only to buy a powerfull soldering iron, but which?

Thank you

peter yetman · Feb 3, 2016

It's all here...
http://www.candlepowerforums.com/vb/showthread.php?414342-best-way-to-solder-leads-to-stars

plata0190 · Feb 13, 2016

What cheap but good soldering paste do you suggest me?
If I understood correctly it contains flux tin metal so don't need extra tin, just have to put it on the pcb metal plate and put the SMD led on?

peter yetman · Feb 23, 2016

DrafterDan said:
I'd love to take your money, but then You'd expect me to do something in exchange

As for reflowing, I can relay the method I used. I put the MPCB in a clamp holder and used my iron on the underside of the board.

I used silver-based solder paste for the LEDs themselves, and regular solder for the wire contact points. The amount to use of the paste is less than a grain of rice. Too much and it will clump on the center thermal contact spot and keep the edges of the LED from touching the anode/ cathode sides. Ask me how I know this...

Use as little heat as possible, otherwise it will discolor the mpcb. Just set the LED onto the solder-pasted contact point and heat it up. When it reaches the right temperature, it will settle itself without any touching/ aligning from you at all. That's why so little paste is used. In my example, the anode (the positive side) of the LEDs were facing away from center. The anode side has the little wires at the edges you can just see on the photo above.

I did one at a time, letting it cool down to be able to touch the board with my bare fingers between. This keeps the overall heat down, reducing damage/ discoloration. I found it helpful (per the video that Old Lumens made) to apply a bit of solder to the tip of the iron before applying to the underside of the mpcb. This helps transfer heat from the tool to the piece.

I then used a CR123 primary to test each side of the quad before I bonded it to the pill. Just a super-quick touch of the leads proved that they were working as desired.

Changing LEDs on a M 43 Noctigan - how to do?

plata0190

Enlightened

richbuff

Flashlight Enthusiast

peter yetman

Flashlight Enthusiast

plata0190

Enlightened

plata0190

Enlightened

plata0190

Enlightened

plata0190

Enlightened

peter yetman

Flashlight Enthusiast

plata0190

Enlightened

peter yetman

Flashlight Enthusiast

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