# LED size...how big can they make them?



## ConfederateScott (Jul 28, 2008)

Could an LED be made that is 12"x12" square? If the tiny ones I see in my Surefire lights make all that light, then how much would a one square footer make? Would it work?


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## tebore (Jul 28, 2008)

ConfederateScott said:


> Could an LED be made that is 12"x12" square? If the tiny ones I see in my Surefire lights make all that light, then how much would a one square footer make? Would it work?



They could make em huge if they wanted it too. However a defect would ruin the whole thing. Think making a CPU the want them small, otherwise larger size would mean more losses per defect. 

The percentage affected by the defect and percent of a defect goes up exponentially too with size.

Using the multi die approach brings up another set of problems of creating drivers able to drive them and the package can only handle so much. Also big multi LEDs have the same problem as the above where a single die failure would mean a defective LED.


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## lctorana (Jul 28, 2008)

Given that a LED die is about 1mm square in size, then 300 x 300 = 90,000 LED dies.

Now if each die is run flat-out at 3.5W, and each LED is pumping out, say, 80lm/W, then we will need a 200 kilowatt heatsink.

I don't CARE how bright it would be - I just wouldn't want to be anywhere NEAR it!​


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## LukeA (Jul 28, 2008)

OLED panels are coming around for that. Not the lumens/mm^2 of our familiar high-flux LEDs, but still cool.

A large LED faces the nightmare of current distribution across its surface, consistent phosphor deposition, and, as mentioned before, is more susceptible to defects in the wafer.


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## R33E8 (Jul 29, 2008)

ConfederateScott said:


> Could an LED be made that is 12"x12" square? If the tiny ones I see in my Surefire lights make all that light, then how much would a one square footer make? Would it work?



Lamina lighting (used to be lamina ceramics) used to make large led arrays.. They were not that efficient though... And they were very expensive..


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## Icebreak (Jul 29, 2008)

Here's Data's bank


Data said:


> One day I was sitting looking at a bunch of Cree LEDs on my bench and wondering, "what can I do with these?" So off I went trying to make something worthy of the black hole.
> 
> The Data Bank 70 uses A123 Systems M1 batteries and aspheric collector lenses. The battery packs are made from Mag 4D tubes. The aluminum plate weighed in at 9lb after machining. It is all one piece of aluminum.
> 
> ...


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## n_den (Jul 29, 2008)

:twothumbs:twothumbs:twothumbs:twothumbs:twothumbs


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## lctorana (Jul 29, 2008)

*Cree-mendous!*

(Night of the Living Cree)


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## noshoes (Aug 10, 2008)

I like it! what a clean design!


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## Tinaled (Aug 11, 2008)

One of advantages of LED is its small size,so why the bigger one?


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