Luxeon 1 Watt and 3 Watt -- What's the real story?

Luxeon 1 Watt and 3 Watt -- What\'s the real story?

What is the physical difference? I've searched around but nobody seems to have any hard answers so let me put the questions in simple terms:

Are the Luxeon 1 and 3 watt emitters physically the same critter?

Is the die the same?

Is the package the same?

Is the difference just some weird bin/sort?

Thanks Gobs in advance,

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real story?

I think they used beefier lead wires and a heatsink made of silver-coated copper rather than silver-coated aluminum. Whether these changes effect performance, I don't know. Also, people suggest that they (lumileds) got a better handle on making more intra- and inter-bin tint consistency, that is, all bins are pretty good nowadays, so they say.

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real story?

They've definitely changed the die->slug thermal path, since the 1W are all rated at 15C/W, whereas the 3W are 13C/W.

However, upon physical inspection, it appears that everything else is identical. Bond wires appear the same. I have many 1W luxeons that share the silver coated copper slug with the 3W. So a slight improvement in thermal pathway, probably combined with some process improvement, and creative binning has produced the L3.

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real story?

I look at the die and I was swearing (I know I shouldn't!) that the 3W is bigger -- I may have been looking at my 5W though -- I have no memory -- I could have been a doctor instead of an engineer.

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real story?

I'll bet that you'll release the magic smoke from most 1W emitters if you try to run them at 700-1000mA like a 3W emitter.

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real st

My purely idle and uneducated speculation is that the dies are binned prior to packaging. Thermal by product is likely the main culpret in damaging the LED. I propose that a more efficient die has its efficiency based on photon production rather than phonon production. A more efficient die can run at higher current levels, producing more lumens with the same thermal byproduct as that of a less efficient die.

So, I propose that the difference, primarily, between the 1W and LuxIII is that of its efficiency or flux. If anyone is still seeing R bin 1W's coming into population, my proposition is less substantial that it might be otherwise. /ubbthreads/images/graemlins/icon3.gif

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real story?

[ QUOTE ]
idleprocess said:
I'll bet that you'll release the magic smoke from most 1W emitters if you try to run them at 700-1000mA like a 3W emitter.

[/ QUOTE ]

I do so on a regular basis, so do many modders here. I've experimentally shown that the fusing current for the bond wires on a 1W luxeon is around 3A. With good heat sinking and a proper thermal path, you can easily keep the junction temperature of a 1W below maximum while driving it at 1A.

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real story?

My VIP centering jig, originally made with a 1W as the stencil, allows the 1W to drop out (just bigger than snug fit). When placed on 3Ws it stays stuck on (snug fit), requiring a gentle push with a plastic straw through the hole above, on the emitter's clear dome. That's about the only physical difference I've noted in these particular batches of 3Ws I have now.

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real st

"My purely idle and uneducated speculation is that..."

Normally I dismiss idle speculation but considering the source, I'll chime in and say I think you're right.

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real st

My understanding, is that the the Lux III is a hybrid of premium die, and the Lux V package.

The Lux V package has the improved heat sinking and current carrying upgrades (larger wire size, etc.) which enhance heat removal and current carrying capacity.

As far as I know, all Luxeon die are 1,000 x 1,000 microns (1 x 1 mm) - even the 1 watt red AlInGaP type. Depending on the product generation, binning, etc affects the current density / brightness of the specific die.

At least some colors of Lux V require 4 die to reach the desired characteristics, but there might be a color that is a single die - cannot remember.

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real st

All Luxeon V are 4-die packages.

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real st

Suppose you drive a StarI at 700mA and have adaquate heatsinking, what do you expect the lumen maintenance to be?

Re: Luxeon 1 Watt and 3 Watt -- What\'s the real st

Random-*** guess would be 10,000-20,000 hours.