Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Bright surface mount led's?

Jay Salonen

#34242

Bright surface mount led's? | 13 May, 2005

Hello,

Does anybody know is there available surface mount leds as bright as You can find at http://www.set-system.com ? See the brightest ones? (superflux types would be ok for me).

Thanks in advance

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CC to myself

#34244

Bright surface mount led's? | 13 May, 2005

Check superbrightleds.com

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GEB

#34245

Bright surface mount led's? | 13 May, 2005

Hi, The brightest ones that I use are Luxeon LEDs which are rated at 5W, which is pretty bright for an LED, you can't look at them when they're on. Heres the link http://www.luxeon.com/gallery/?filter=luminaires

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Jay Salonen

#34251

Bright surface mount led's? | 13 May, 2005

Thank's I'll check that out

:)

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#34421

Bright surface mount led's? | 23 May, 2005

What is your application / need. I believe I could get you SMT LED's brighter and more cost effective than any of those.

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Rob

#34430

Bright surface mount led's? | 24 May, 2005

Hi Doug,

Can they be mounted on standard FR4 PCBs & reflowed at Lead Free temperatures?

Cheers,

Rob.

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#34446

Bright surface mount led's? | 24 May, 2005

The Luxeon probably are the brightest available. I say probably only because this changes every day. The Luxeon require special mounting as they must be mounted to an aluminum cored PCB with thermal adhesive and then the leads soldered to the PCB. They will not go through a reflow oven and the leads must be either hand or robotic soldered.

THe brightest readily available LEDs are probably Siemens Golden Dragons at 350 -400 mA. That current is state of the art next to the Luxeon.

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#34736

Bright surface mount led's? | 4 June, 2005

Has anyone tried to use electrically condctive adhesive rather than solder to connect the leads on 5 watt Luxeon parts? If you design the board right to dissipate heat, when you have a bunch of them in a tight array, even with thermal relief on the traces, you cant hand solder these in less than 10 seconds.

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Rob

#34755

Bright surface mount led's? | 6 June, 2005

Yes, Loctite 3880. It works out at about $160 for a tube of 30ml. It can be dispensed or printed.

We found you needed a lot less than with solder as it doesn't wick or spread much.

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cmiller

#34764

Bright surface mount led's? | 6 June, 2005

How do apply it in your process? It would seem best to screen the electrically conductive epoxy then dispense the thermally conductive epoxy to bond the part to the heat sink pad. Any help or opinions would be appreciated. I dont think the System Unitek has to solder them will do it in under 1.5 seconds as the part spec reccomends. We tried using selective soldering in a Ersa Versaflow and with pad modifications it could work but a lot of solder wicks up by the body of the part and the lenses seem to cloud.

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Rob

#34765

Bright surface mount led's? | 6 June, 2005

We did the trial by dispensing (both the thermal & the electrical), but in production I would definitely use a stencil for the Conductive adhesive, as the shape, spread & volume of the adhesive is critical. (No wicking or spread)

We also looked at Robotic soldering as you can control the heat & contact times accuratly, however with the ROHS directive on the horizon, we thought we'd wait & see on that one.

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cmiller

#34766

Bright surface mount led's? | 6 June, 2005

How do apply it in your process? It would seem best to screen the electrically conductive epoxy then dispense the thermally conductive epoxy to bond the part to the heat sink pad. Any help or opinions would be appreciated. I dont think the System Unitek has to solder them will do it in under 1.5 seconds as the part spec reccomends. We tried using selective soldering in a Ersa Versaflow and with pad modifications it could work but a lot of solder wicks up by the body of the part and the lenses seem to cloud.

reply »

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