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Indium foil on a 5w 650nm C-mount diode?

Minamoto Kobayashi

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Hi to all.
I ordered the Stubby Red it from Jayrob, and I wish to use an indium foil between the diode and the copper heatsink, but I have three important questions for You:

- It's necessary, or it's simply "better" ?
- What is the right thickness? I heard that a wrong thickness may cause
opposite results!
- Eventually where I can buy it? (I'm from Italy)

:thanks:
 

CDBEAM777

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No...Do NOT use any Indium foil. No need. Hard to believe, but these run only slghtly warm when driven at 3A. No foil and USE NO THERMAL PASTE OF ANY KIND! !!!

LivingLoud also suggested sanding down the area where the diode will be mounted with a progressive grit of sand paper....like 300,600,1500.

I think this a good idea too! !!!!!!! Perhaps the Jayrob CU heatsink is already this way ?? Dunno?

Wear a grounding strap at ALLtimes when handling the LD.

Keep away from the bond wires and FAC Lens! !
In general, MINIMAL HANDLING OF THE LD is recommended!

This LD produces a completely beautiful beam and color! !!!!!!!!!!!!

I make these suggestion as a precaution! !!!! I do NOT think the LD is that sensative!!!

But as a precaution....trreat it with CARE !!! GO SLOW! !

CDBEAM=======>
 
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Minamoto Kobayashi

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Hi!
Yes, the copper surface is almost smooth, but I may use some copper finishing product for smoothing fine, and clean with isoprophilic alcohol, that is the most dry cleaning product available.
FAC is alredy mounted and it's absolutely needed to have a decent beam!
Thanks for the hint.

Richard.
 
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lazeerer

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IMO if you can get some Indium foil then do so.

It does not hurt and can only make it better.

But its not a must. As long as you sand down the block its getting mounted to that "Should" be enough.

Think of it this way. when you press a diode into a module you normally use thermal paste to help but its not needed. IT HELPS But its not needed.

Same concept for the C-mount and indium foil.

The Thinner the better it will work.:)

:beer:
 
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Minamoto Kobayashi

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Thanks Angelos for the hint!
But indium is both thermal and electrically conductive? I ask so because I need a positive path between diode chassis and copper heatsink.
Where I can buy it?
:thanks:
 
Last edited:

BShanahan14rulz

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Whether or not you should use it, I won't comment either way, because I have not used indium foil. It is basically a low temp melting metal, and it does conduct electricity, but the concept is the same as most other interface materials. I would think that the smoother and flatter the surfaces to be mated are, the thinner indium you would need if you decide to use it.I think it is meant as a material that will "wet" to both surfaces, and would be great for mounting something to something else that hasn't been smoothed flat and polished.

Random comments:
Gallium is a metal that melts at a low temp too, much lower than indium. Coincidentally, LDs and LEDs on the blue side of the spectrum are made using a "blend" of indium, gallium nitrides. And I think this material is transparent!
 

Sigurthr

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Whether or not you should use it, I won't comment either way, because I have not used indium foil. It is basically a low temp melting metal, and it does conduct electricity, but the concept is the same as most other interface materials. I would think that the smoother and flatter the surfaces to be mated are, the thinner indium you would need if you decide to use it.I think it is meant as a material that will "wet" to both surfaces, and would be great for mounting something to something else that hasn't been smoothed flat and polished.

Random comments:
Gallium is a metal that melts at a low temp too, much lower than indium. Coincidentally, LDs and LEDs on the blue side of the spectrum are made using a "blend" of indium, gallium nitrides. And I think this material is transparent!
Gallium metal is not transparent, but the nitride crystals can be. Gallium metal will disperse into aluminium metal lattice and dissociate the aluminium oxide layer that protects it from the atmosphere from the internal metal, causing rapid corrosion of the aluminium. Gallium is never to be stored or used around aluminium or magnesium for this reason.
 




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