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Darth Lars
09-13-2007, 02:26 PM
I have copper heatsink that I want to mount a K2 to. (not a K2 Star)
What is the best method to use?

1. Would it be safe to solder the 'No Connect' leads to the heatsink?
2. How about soldering the heat plate on the bottom of the LED package to the heat sink using soldering paste?
3. Should I use thermal epoxy? But it does not conduct heat as well as thermal paste or solder (which is metal), right?
4. ... or should I drill tiny holes in the heat sink and attach it using tiny screws? (the most difficult option..)

Luxeon-gurus: What are your experiences with any of these options?

TimeRender
09-13-2007, 03:38 PM
I am pretty sure that all four leads on the luxeons are connected to the LED, or perhaps I am misunderstanding you. At any rate, you cannot solder any leads from the LED to a piece of copper because copper conducts electricity. If you mount your LED to this heatsink, you must be very careful to avoid making any electrical contact with it or your saber may not work. Gluing it down is fine as long as those leads never touch the heatsink. Also, you may have trouble mounting your lens in place if you don't use a star. I wouldn't recommend it. Since K2 stars are only 8 dollars, you should definitely consider picking one up.

xwingband
09-13-2007, 06:00 PM
Thermal epoxy is your best bet. I wouldn't solder anything to the heatsink... both leads on each side go to the die.

In my experience thermal epoxy works fine for transferring heat if you do it in just the right amount. If you have a bare emitter other than a really tight press fit there isn't a better way to go. In fact I'd do both if you can.

Thermal tape could work well too, but that one I'd only be happy if it was press fit also.

pockets
09-14-2007, 05:16 AM
thermal tape sucks, its a great way to fry a processor, never used it on an LED before though. i'd stay away from it though. a tiny dot of Arctic silver 5 and a little bit of pressure should do u fine.

xwingband
09-14-2007, 09:30 AM
For processors... I've used thermal tape before. Works just fine. I use it on all of my Red type LEDs so they don't ground out the base.

Darth Lars
09-14-2007, 10:53 AM
Thanks guys!

I am also considering fabricating a custom clamp to press the LED against the headsink. Simply a plate with a hole for the lens and a few holes for screws.