Lumileds Luxeon V, test of a 4000K 70CRI emitter

[Tom_E]

In a quad, probably 5 amp per LED at best, so sounds like it's still in the safe zone. 20 amps is pretty high for typical compact quads.

So guess for those using the V's on a quad, you reflowed the 4040 V onto 3535 pads? I was only using L4P's 4040 MCPCB's.

[Scallywag]

@KevinZA1988

I don’t think driving this LED with FET is a good idea. I lost half of my output (physically two of the 4 four emitting surfaces stopped working) using a LD-A4 driver. I had high mode set to direct drive and it was a huge mistake. Had to replace the LED. Currently, I’m running high mode constant current at 5.25A. It’s been months of heavy use and lots of turbo runs and it’s still as it was since I tested it after the new LED was installed.

I missed this. A bit confused: Is the Luxeon V 4 dies?

@Tom E

In a quad, probably 5 amp per LED at best, so sounds like it’s still in the safe zone. 20 amps is pretty high for typical compact quads.

So guess for those using the V's on a quad, you reflowed the 4040 V onto 3535 pads? I was only using L4P's 4040 MCPCB's.

No, I'm using Led4Power's 20mm 4xV MosX MCPCB

[Tom_E]

Ohhh - that 4040 quad is not listed under his MCPCB's, so guess he doesn't sell them bare :facepalm:

Yep, I'm still confused bout the 4 dies as well.

And since a couple guys chimed in about running these at high amps, djozz is either unaware, or didn't take time time to update his OP, because reading the OP, everything is fine and dandy with the Luxeon V at up to 12 amps or so...

Certainly that L4P quad or triple seems to be the best way to go with these LED's, or, be sure you constrain the amps way down, under 6 I suppose.

[M3CSL]

MOSLED EXTREME ( mosX ) ceramic insulation 4XV 4040 quad MCPCB (BARE) is here:
https://led4power.com/product/mosled-extreme-mosx-ceramic-insulation-4xv-4040-quad-mcpcb-20mm/

It is on page 2 and easy to miss. Can only find the AL version though.

[Agro]

Lumileds claims that Luxen V has a single die:
https://www.lumileds.com/news/299/50/Lumileds-Transforms-High-Power-Category-with-1-700-Lumen-Single-Die-LED

KevinZA1988 do you have any pictures of the failed LED?

[Scallywag]

@Agro

KevinZA1988 do you have any pictures of the failed LED?

Yes, ideally both lit partially as described, and un-lit.

[led4power]

I think Kevin is talking about Luxeon MZ, which is quad 4x2mm2 die LED. Luxeon V is single 4mm2 die LED.

MosX boards more than good enough for triples, quads etc. because no one run LEDs at absolute max. in those setups - difference between DTP and mosX is marginal when you run LEDs like XPL, Luxeon V at 50-70% of max. current.

[Tom_E]

@led4power

I think Kevin is talking about Luxeon MZ, which is quad 4x2mm2 die LED. Luxeon V is single 4mm2 die LED.

MosX boards more than good enough for triples, quads etc. because no one run LEDs at absolute max. in those setups - difference between DTP and mosX is marginal when you run LEDs like XPL, Luxeon V at 50-70% of max. current.

MZ explains it - details, details...

What's your definition of max current?

Are all MosX boards aluminum? Guess so... From this listing on a Luxeon V quad, I had no idea a MosX board is alum - would have fooled me for sure...

I'm surprised in triple and quads you are saying alum is no worse than copper - think about it, quads have 4 times as much heat, though amps per LED is lower, but the heat is not reduced.

[Agro]

@Tom E

@led4power

I think Kevin is talking about Luxeon MZ, which is quad 4x2mm2 die LED. Luxeon V is single 4mm2 die LED.

MosX boards more than good enough for triples, quads etc. because no one run LEDs at absolute max. in those setups - difference between DTP and mosX is marginal when you run LEDs like XPL, Luxeon V at 50-70% of max. current.

MZ explains it - details, details…

What’s your definition of max current?

Are all MosX boards aluminum? Guess so… From this listing on a Luxeon V quad, I had no idea a MosX board is alum - would have fooled me for sure…

I’m surprised in triple and quads you are saying alum is no worse than copper - think about it, quads have 4 times as much heat, though amps per LED is lower, but the heat is not reduced.

This PCB w/out LEDs is in the “MCPCBs - ALUMINUM” part of the shop. And there’s no copper mentioned anywhere. And weight is low for copper.

[Tom_E]

Yep, I know all that for the bare alum board, but for the pre-mounted quad in the listing I linked -- nothing about alum, copper or weight.

It's confusing without reading every post on BLF about this stuff...

[Agro]

@Tom E

Yep, I know all that for the bare alum board, but for the pre-mounted quad in the listing I linked — nothing about alum, copper or weight.

It’s confusing without reading every post on BLF about this stuff…

Actually weight is available under “Additional Information”.

But I agree, these could have been clearer.

[djozz]

Here is a quick picture of my C8F with Luxeon V’s . You can see that one is only lighted half. I did not know that one-quarter and three-quarter were also possible. You can not see individual dies though, I do not know how the led is built up.

[Scallywag]

Ouch, no fun.

[Agro]

Thanks djozz! That’s very interesting.

[Marc_E]

@djozz

Here is a quick picture of my C8F with Luxeon V’s . You can see that one is only lighted half. I did not know that one-quarter and three-quarter were also possible. You can not see individual dies though, I do not know how the led is built up.

Is that definitely the die failing and not the dome separating from the die?

[The_Driver1 (The_Driver)]

Multiple dies would explain the very low Vf of these LEDs. It’s much easier that way.

[djozz]

@Marc E

@djozz

Here is a quick picture of my C8F with Luxeon V’s . You can see that one is only lighted half. I did not know that one-quarter and three-quarter were also possible. You can not see individual dies though, I do not know how the led is built up.

Is that definitely the die failing and not the dome separating from the die?

I have had more than a few doing this, and the shadow over the led was always the same size: about half the led not lighted.

[Marc_E]

@djozz

@Marc E

@djozz

Here is a quick picture of my C8F with Luxeon V’s . You can see that one is only lighted half. I did not know that one-quarter and three-quarter were also possible. You can not see individual dies though, I do not know how the led is built up.

Is that definitely the die failing and not the dome separating from the die?

I have had more than a few doing this, and the shadow over the led was always the same size: about half the led not lighted.

That’s fair enough. It’s just that as i was unknowingly tearing the dome off an XHP50.2 it looked like one quadrant was failing, then that three were failing with a similarity to your picture.

[kikkoman]

Physically it’s clearly one die (see page 5) but it seems internally / electrically it’s 4. This is from the STEP file provided by Lumileds, you can’t see it in this projection but these pads are on the top plane of the substrate.

edit: see here, same plane as the ESD diode pads

[Scallywag]

@kikkoman

Physically it’s clearly one die (see page 5) but it seems internally / electrically it’s 4. This is from the STEP file provided by Lumileds, you can’t see it in this projection but these pads are on the top plane of the substrate.

Cool! Thanks for posting this.

I hadn't read through this whole thread, but I just skimmed most of it. I'll definitely limit my remaining Luxeon Vs to below 6A (assumed in the case of the D4) to prevent killing them. None have seen one-on-one time with a FET yet, so they should all be fine.