LED emitter boards and plastic (3D printing)?

Is there a clever way to use standard 16 or 20 mm MCPCBs with plastic parts - like a small heat sink that sticks out?

I have seen some designs that are limited by bad heat transfer. Temperature is not really an issue for the plastic (PET and PC can handle up to 120°C/248°F) but we all know about our poor emitters…

Any ideas?

120°C can be not enough to overdriven LEDs

DTP MCPCBs use a part that sticks out to directly sink the LED with the base copper material
the traces and insulator add up to the rest of the board so the surface seems planar

the advantage is also some heat gets conducted by the solder points for current

Why would you want to use a plastic heatsink with such high power parts?

Thermal resistance of non metal infused plastics is very very high compared to an aluminium/copper MCPCB, so you’d kill the LEDs quite quickly.

Maybe they are talking about a plastic host with a DTP MCPCB and some sort of external heatsink attached to the MCPCB to get the heat out?

EDIT:

If this is the case, I’m not sure what “over the counter” heatsink designs would be suitable… If you can make a good heatsink (metal, lots of surface area), you can probaby make a flashlight host. This would be neat for transparent designs that show off the insides though.

Maybe you can make a “pill” of sorts, and sandwich it between the bezel and the tube, leaving it exposed for heat transfer to the air? I’ve seen some heatsinks made with copper bar, pipe, or stacked sheets.

Something like this where the blue is plastic and the orange is the metal:

Another option could be something like what they do in computers these days, and move the heat out to a larger heatsink with heat pipes… this might give you more options for a non tube style light… Not sure what you are going for.

f0xx is right. I want a plastic body with LED board that is not overheating. Use it as a garden sport or office light. Maybe flashlight later.
A metal heatsink seems the best bet but I cannot find a nice one that will not destroy any design.

Lexel, if I could avoid thermal runaway under 120°C it would still be too hot to handle as a flashlight or office lamp.

Transferring the heat by heat pipe or copper bar sounds like a good idea. It moves the ugly heatsink away from the board.
I will calculate how good f0xx’ orange heat sink would work.

You have to solve two problems: move the heat away from the emitters and let it escape the heatsink, so make sure the heatsink has contact with the air.

Fins provide more surface area, so alternating discs of different sizes should work better than a solid cylinder (with the same mass). If copper, you could solder the layers together. Aluminum, I guess you could use thermal epoxy or screws/bolts.

There are flashlights with metal core and a rubber/plastic on top of that

Wall thickness could be down to 0.5 mm but I would need good thermal transfer. No air between metal and wall.