My Luxeon gets golden

win67

win67

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What's that? The Luxeon I inside my Fenix L1P gets visible golden, round the die/phospor of the emitter, where it is normally silver plated...
Never seen this before....



Jens
 
monkeyboy

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That's just the reflection of the phosphor. It just means the reflector is doing what it's supposed to do.
 
E

evan9162

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I have a lot of older luxeons that are doing this too.

The silver turned gold part you are seeing is the top of the heat sink slug of the emitter. The hexagonal shaped silicon submount is thermally attached to the top of the slug, and the square shaped die (covered by yellow phosphor in the case of white Luxeons) is attached to the top of the silicon submount.

The heat sink slug is copper plated with silver. The silver is likely tarnishing. I have several luxeons with many thousands of hours on them that are exhibiting the same phenomenon. The silver is tarnishing on the top of the slug. It's not a result of poor thermal management (the luxeon is not getting overly hot) since many of mine which have tarnished have excellent heat sinking and only get a few degrees above room temperature.

I don't think there's anything to worry about. The silver on the top of the slug tarnishing won't affect the device in any way.
 
jtice

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exactly what monkeyboy said,

if the reflector is filling up completely with the reflection of the LEDs yellow phosphor, then its designed well.

Some reflectors dont use their entire surface area to actually reflect the LED.

~John
 
win67

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evan9162,

so I'm relaxed now... Thank You!
But no more reason to mod it to a SxxH :-(

Jens




evan9162 said:
I have a lot of older luxeons that are doing this too.

The silver turned gold part you are seeing is the top of the heat sink slug of the emitter. The hexagonal shaped silicon submount is thermally attached to the top of the slug, and the square shaped die (covered by yellow phosphor in the case of white Luxeons) is attached to the top of the silicon submount.

The heat sink slug is copper plated with silver. The silver is likely tarnishing. I have several luxeons with many thousands of hours on them that are exhibiting the same phenomenon. The silver is tarnishing on the top of the slug. It's not a result of poor thermal management (the luxeon is not getting overly hot) since many of mine which have tarnished have excellent heat sinking and only get a few degrees above room temperature.

I don't think there's anything to worry about. The silver on the top of the slug tarnishing won't affect the device in any way.
 
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evan9162

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jtice said:
exactly what monkeyboy said,

if the reflector is filling up completely with the reflection of the LEDs yellow phosphor, then its designed well.

Some reflectors dont use their entire surface area to actually reflect the LED.

~John


He's not talking about the phosphor reflecting in the reflector, he's talking about the tiny silver ring around the phosphor that's part of the emitter its self - the top of the heat sink slug.

I will post macros tonight to show the difference.
 
EngrPaul

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win67 said:
What's that? The Luxeon I inside my Fenix L1P gets visible golden, round the die/phospor of the emitter, where it is normally silver plated...
Never seen this before....



Jens

It's oxidation from singing into it. Save it for karaoke night and use a real mic.
 
monkeyboy

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evan9162 said:
He's not talking about the phosphor reflecting in the reflector, he's talking about the tiny silver ring around the phosphor that's part of the emitter its self - the top of the heat sink slug.

OK now I get it :ohgeez:

That would make a lot more sense for the start of a new thread.
 
HiltiHome

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EngrPaul said:
It's oxidation from singing into it. Save it for karaoke night and use a real mic.

I'm singing in the rain...:lolsign:
 
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evan9162

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Here it is:

tarnlux.jpg


These two luxeons are the same age, from the same tree of stars. The one on the left only has ~100 hours on it, and has been in a bin in my garage for 3 years now. The one on the right has been used ~2 hours/day nearly every day for 3 years in a set of lanterns in my living room. There are 9 others in that set that are also tarnishing. These are the only ones that I've noticed that have tarnished, but are the ones with the most use (several thousand hours).
 
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evan9162

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Here's the tarnished one all by its self:

tarnlux2.jpg
 
WildChild

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Does it dimmed much or it is still going strong? Well cooled?
 
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evan9162

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Haven't noticed any dimming. They are all attached to a 3"x3" or 4"x4" 1/16" aluminium plate. The 3" sq plates run about 5C above room temp, the 4" sq plates run only 1-2C above room temp.
 
LEDcandle

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Well as they say, "Old is Gold".. I guess they meant it for Luxeons too.... :laughing:
 
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evan9162

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Now I'm just trying to figure out how to get some silver polish in there...
 
Christoph

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Evan

I have been wondering about that.I have a ARC4+ with a lot of hours on it that looks just like your led.
C
 

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