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I have bought this UV LED for experimental purposes. I do not want to go to the expense of creating a miniature PCB to mount it, but I obviously need to heatsink it. It is tiny - 3.3mm x 3.3mm and can dissipate up to 3W (when properly mounted and cooled, I assume).

Are there any shortcuts people can suggest? It is not (yet) for a production item and it only needs to work for a few hours evaluation.

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    \$\begingroup\$ Stripboard/Veroboard (if the pads line up) + underpower it + cooling fan? \$\endgroup\$
    – pjc50
    Feb 2, 2018 at 10:30
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    \$\begingroup\$ I think I would use a piece of prototype PCB, the kind with copper on one (or both) sides and no holes. If the copper is reasonable thick and about 10x10 cm that might provide sufficient cooling. Some additional airflow (a fan) will also help. \$\endgroup\$ Feb 2, 2018 at 10:32
  • \$\begingroup\$ I doubt whether a cooling fan is going to be much good at that small a scale. Also, I can't underpower it too much because I need a significant UV flux \$\endgroup\$ Feb 2, 2018 at 10:33
  • \$\begingroup\$ @Bimpelrekkie Maybe. Perhaps hand cut my own PCB with a scalpel under a microscope? \$\endgroup\$ Feb 2, 2018 at 10:34
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    \$\begingroup\$ You could but I'd simply use bare wire to solder the Cathode to the copper plate directly and for the Anode use a high value resistor or a capacitor as an isolator. Then you can solder a mechanical support but isolate the contact from the Cathode. \$\endgroup\$ Feb 2, 2018 at 10:36

2 Answers 2

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Why don't you use a small heatsink (less than 40x40mm), solder two solid core wires to the two pins on the LED, make sure they don't short on the heatsink (with some insulation tape or something similar), and bend the wires down and around the fins of the heatsink.

This might sound kind of... unprofessional, but it's something I've done when working with small one watt LEDs. And you also said that It's only for a few hours of evaluation. The solid core wires hold the led in place really well. You could also add a bit of thermal paste to the LED to increase thermal conductivity. And also a small fan to keep temps low, if that is required.

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Just attach it to a small plate of aluminum or a cheap hetsink using thermal conductive adhesive. Size of the Aluminum plate depends on how high you allow your Delta T to be.

You can approximate the thermal resistance of the aluminum part to air using this formula:

Rth = 1/(α x A)

α ... heat Transfer coefficient [W/m²K] (ca 5 for free convection) A .. Surface area of the aluminum part [m²]

Eg.: 10x10cm aluminum plate results in an approximate Rth = 30K/W

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    \$\begingroup\$ We do something similar with these 365--370nm LEDs, except they can be screwed through the notches with thermal grease underneath. When we run a cluster of 4 of them at 1A we use a big old heatsink, but for 1, we use a sheet of 2mm aluminium (photo at chemistry.se). This gets a little warm behind the emitter, but we can barely detect the drop-off in efficiency with increased temperature even at 1A (so probably about 10C rise). \$\endgroup\$
    – Chris H
    Feb 2, 2018 at 12:04

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