LED`s and heat?

When overdriving LED`s does one lead get hotter than the other?

I would think the side the die is on would get hotter.

Thats what I am thinking...the other side may have little or no heat transfer...maybe it`s only necassary to heat sink that side. Craig, Brock anybody else have a thought?

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by KenB:
Thats what I am thinking...the other side may have little or no heat transfer...maybe it`s only necassary to heat sink that side. Craig, Brock anybody else have a thought?<HR></BLOCKQUOTE>

Normally, the most important heatsinking goes on the cathode lead. The bond wire is so thin that relatively little heat goes directly in; the rest is conducted through the plastic and into the anode lead.

Note: Some 660nm red LEDs have the internal parts all *** backwards, so the anode would be heatsinked. But for all of the currently available 3mm and 5mm white, heatsink the cathode.

A well-heatsinked LED can potentially last its full 100,000 hours up to 45mA.

Thanks Craig, that should make things a lot easier for the do it yourself group