What is this disc lookin' thing in my new L0D CE Q2 emitter ...?

[Lite_me]

I got to looking at my new L0D CE Q2 Special Edition's emitter a little closer and noticed this disc looking thing inside. After taking a few pictures of it and looking at them a bit, it seemed to trigger a thought that I've seen a picture/post like this before. Have I?

What is this? Is it common? Is it a concern? Anyone know? :thinking:..... the last pic probably gives the best look.

EDIT: After looking at it some more with a 16x jewelers magnifying glass, it looks like solder. Could it get hot enough to melt!? That wouldn't be good.
EDIT2: Looked that up. Looks like solder melts @ around 360°F. Shouldn't get that hot.
EDIT3: I put a fresh NiMh Hybrid in it, fired it up on hi and let it run for 30min tail standing. Didn't see any apparent changes.

 

[WadeF]

Interesting. Looks like an air bubble.

 

[Kilovolt]

Yes, it looks like an air bubble in the silicone dome of the LED. Does it show in the beam during white wall hunting? :duh2:

 

[easilyled]

Could it also be a chip in the glass dome of the Cree?

 

[Fallingwater]

I thought special edition lights were supposed to have spotless emitters...
I'd expect bubbles in cheap, factory-second ones.

 

[Jay R]

Yup, that's a bubble or crack. Tons of Crees have them. Cree Q2s have higher output, nobody said anything about flawless emitters. I wouldn't worry about it as it's not going to affect anything by more than a fraction of a percent.

 

[FirstDsent]

The glass dome on the XR-E is not firmly retained. There is no adhesive, and the silver ring is not a retainer. The dome is primarily held in place by the surface tension of the silicone gel that fills the void between the die and the dome. I accidentally pulled one off while trying to lift the emitter. Once the dome is tweaked, air bubbles form in the gel underneath. There's no practical way to restore it.

Your emitter may have been damaged during manufacture at Cree, or more likely was damaged by the technician assembling your light. It will refract light if it is in the forward transmission path of the light. That may reduce the total light emitted from your light. Send your pictures to Fenix. They may offer you a replacement.

Bernie

 

[EngrPaul]

+1 on Bernie's post.

I would be concerned that the defect spreads.

Any gaps in the seam between the layers can lead to light being reflected back at the die instead of reaching outside the emitter, just like you are seeing a mirror effect from the outside looking in.

You paid for a premium emitter and an extra small % of output, don't let the extra output be offset by the refractive defect.

 

[greenstuffs]

Why not you paid premium price over the regular version and i would not worry about it if every one else's light have the bubble. I see no reason why my money should reach less mileage than another Fenix Owner. I have not read in the description of the light about a cosmetically challenged LED.

Yup, that's a bubble or crack. Tons of Crees have them. Cree Q2s have higher output, nobody said anything about flawless emitters. I wouldn't worry about it as it's not going to affect anything by more than a fraction of a percent.

 

[chimo]

+2 on Bernie's post as well.

 

[nanotech17]

The silicone gel is baked in the dome itself maybe it's due to overheating while soldering the emitter or poor heatsinking.
Speak from experience.

 

[Kiessling]

Not to sound overly pessimistic ... but the emitter of one of my U2s looked like that ... and it actually got bigger untill the light dimmed and died. It had to be replaced.

 

[:)>]

Where did the MOP reflector go?

-Goatee

 

[Burgess]

the Fenix Special Edition L0D-CE flashlights do NOT have the "medium orange peel" reflector.

Only the Larger Versions (Special Editions) have that.


Just rcd. my Special Edition L0D-CE-Q2 this afternoon.

Very nice, indeed !

 

[ernsanada]

I got to looking at my new L0D CE Q2 Special Edition's emitter a little closer and noticed this disc looking thing inside. After taking a few pictures of it and looking at them a bit, it seemed to trigger a thought that I've seen a picture/post like this before. Have I?

What is this? Is it common? Is it a concern? Anyone know? :thinking:..... the last pic probably gives the best look.

EDIT: After looking at it some more with a 16x jewelers magnifying glass, it looks like solder. Could it get hot enough to melt!? That wouldn't be good.
EDIT2: Looked that up. Looks like solder melts @ around 360°F. Shouldn't get that hot.
EDIT3: I put a fresh NiMh Hybrid in it, fired it up on hi and let it run for 30min tail standing. Didn't see any apparent changes.

My LOD CE Q2

 

[chesterqw]

the "rings" are reflections of the reflector(no pun intended).

 

[2xTrinity]

One of my DX Cree stars ended up with an artifact like that, I assume it was a chip in the glass from being bumped during shipment. Overall output didn't appear to suffer, but it did create a noticeable beam artifact. I would request a replacement to be safe though -- if it's a crack, you don't want to risk the thing spreading and screwing up your light further.

 

[Lite_me]

Thanks for all the feedback guys. I still haven't decided what to do but it's looking like I'm going to contact 4sevens for a replacement.

I don't know anything about LEDs or their manufacturing, but being able to look at this thing closely with this jewelers magnifying glass, I can say that it's no air bubble. It is wafer shaped, like a splat of solder. Some of the solder is layered/cracked like, and a piece is curled up near the top. The bottom edges of the piece are jagged. You can see it in my pictures. It shows up as a shinny spot. Under where that curled up piece is from, the surface (or whatever)looks dull. It's solder guys. I just don't know how it got in there during the manufacturing process.

Before discovering this anomaly, I posted my observations about this light in ernsanada's review thread. Here... In there I stated that I thought mine was an underachiever. Not sure how, but this could have something to do with it.

Thanks for your pic Erin.

 

[MidniteTweeker]

I recently purchased several CREE XR-E Q2's reflowed onto stars. I noticed the same type of feature on half of them. Actually, most of the defects I encountered were larger than the one shown in the photos.

I took a couple macro shots & would post them here but do not have a hosting site.

One of the features appears to be mostly in a vertical plane; that is, light emitted from the die would go past the flaw instead of through it. And a good thing, too, because when viewed from the side the flaw appears like a silvery mirror. It definitely looks like a change in the refractive index of whatever material that is. How much light would be reflected if it hit the reflective feature directly is a question, but it can't be a good situation.

The other feature was circular and went around the interior of the dome above the die, kind of like the metal retaining ring except on the inside. It covered about 270 degrees around the inside perimeter of the dome. This one in my opinion is potentially more serious because the reflective areas are perpendicular to the light, and form a lot of swirls and curlies.

I'm new to this & don't understand the way an XR-E is constructed, but what I saw certainly looks like an internal fracture of some kind. I'm told by the seller they are bubbles formed during reflow due to the presence of humidity and are normal. Also, according to the seller, they have forwarded my photos to CREE for more definitive analysis.

I paid what I consider to be a premium price for these and am having a hard time swallowing the idea that this is normal. But I'll withold judgement on the matter until I hear back.

MT

 

[Lite_me]

MidniteTweeker, thanks for your reply and welcome to the forum.

I'm having a hard time believing this is "normal". And mine is no air bubble. It has texture and some of the surface is pealed up with jagged edges. I'd call this a defect.

I would love to see your pictures. You don't need a hosting sight of your own, you can use one of the free ones (like I do). Either
http://www.imageshack.us/ or http://photobucket.com/ will do. I think you have to register on Photobucket but I didn't for Imageshack.

Also, let us know here if you hear anything back from Cree. I'm sure there are many following here that would like to hear what they have to say.