Idle Question: No epoxy for high temp dies?

Just had a thought. It seems that manufacturers are improving the types of resin being used in LEDs. We've gone from hard plastic to the strange semi-rubbery stuff you find on K2s and Golden Dragons.

Presumably the new resin doesn't do as much mechanical trauma to the die/wire bond when the LED heats up/cools down, and junction temps (hence forward current+brightness) can increase.

What about the old style 'LED in a can' type LEDs with modern dies and heat sinking methods. The LED would be in a metal can, presumably sealed and the lens would be on top. There would be no resin about the die/wire. I'd imagine something similiar to the UV EPROM windows, but with better heatsinks.

No doubt this would be much more expensive....but would they actually allow even higher junction temperatures and LED outputs?

Phil

You mean like these?

http://www.roithner-laser.com/All_Datasheets/LEDs/FAT-655-40.pdf

Or were you thinking more like these?

http://www.bivar.com/default.asp?p=p_detail&c=Discrete+LEDs&prid=UV-395-TO92

mmm....almost.

The TO-92 can was similiar to what I was referring to, with regards to not having a resin surrouding the die and a lens ontop. However I was wondering about some more meaty heatsinking in a more modern construction. Something like a high power 'can' on a K2 like SMD package. Those weedy little leads wouldn't carry much heat out of the device.

The screw device looks interesting, but I suspect from the specs the die inside is pretty humdrum....The screwin approach is probably a bit of overkill.

Phil