Why are LEDs getting tinier?

[anuragwap]

Deleted!

 

[mvyrmnd]

If asked, I would have thought the trend is for LED's to be getting bigger! Consider the progression of common flashlight LED's over the last few years, from the XR-E to the XP-G to the XM-L.

Smaller LED's are better for flashlight applications, as a smaller source of light is better focused in a reflector for more throw.

 

[anuragwap]

Deleted!

 

[Steve K]

my guess would be that the manufacturer saves money by using smaller LED dice, as well as using smaller packages. A wafer of semiconductor material is pretty expensive, and if shrinking the dice lets them get more LEDs out of the wafer, then the manufacturer's cost goes down.

I see the same thing happen in general purpose IC's. As semiconductor manufacturers learn how to make smaller transistors on the wafer, they can get more op-amps, voltage regulators, etc., from a wafer. A side benefit is that the package can be very small, permitting the production of more compact electronics. The downside, as noted, is that it's pretty much impossible for a human to solder the darned things!

 

[Optical Inferno]

my guess would be that the manufacturer saves money by using smaller LED dice, as well as using smaller packages. A wafer of semiconductor material is pretty expensive, and if shrinking the dice lets them get more LEDs out of the wafer, then the manufacturer's cost goes down.

I see the same thing happen in general purpose IC's. As semiconductor manufacturers learn how to make smaller transistors on the wafer, they can get more op-amps, voltage regulators, etc., from a wafer. A side benefit is that the package can be very small, permitting the production of more compact electronics. The downside, as noted, is that it's pretty much impossible for a human to solder the darned things!

+1. Smaller means more LEDs from a single waffer, means more money in the manufacturers pocket. Now that performance from LEDs like the XB-D are comparible to those of an XP-E it also allows end users to design smaller optics and save on other materials for their products.

I wouldn't be surprised if this trend continues to the point we get XP-G performance out of something like a small PLCC-4 LED.

 

[Gunner12]

I think the LED dies have stayed relatively similar in size, or even gotten bigger. The XP-G and XM-L have a larger die size then the original XR-E or Luxeon I and IIIs. The packages have gotten smaller, but the LEDs themselves have not changed too much in size.

I think smaller package = lower production cost.

 

[mattheww50]

One of the continuing themes over the past 40 years of the semiconductor industry is reduction in feature size. The reduced feature sizes means that for a given circuit, you can fit more of them on a single wafer. The Fab cost is pretty much per wafer, so smaller features mean higher device yields per wafer, and more revenue/profit per wafer (and usually lower power as well). This process can be a double edged sword. It does mean more devices per wafer and higher revenues/profits for the manufacturer. The bad news is that the noise immunity can take a serious hit, and the timing can be altered. I've been burned on both counts. Unfortunately the manufacturer rarely tells you they have shrunk the die size. You just wake up one morning and the design no longer works very well. That's usually when you discover the manufacturer shrunk the die, or made some other 'improvement'....

 

[blasterman]

As per above, cheaper manufacturing.

With dedicated, high performance fixtures increasingly using multiple emitters driven at low currents, and other big chunks of the market segment moving towards remote phosphors nobody needs a 3amp handling.

 

[WeLight]

what they said...
Do the math a wafer cost $150.00, gives you 1000 die, half the die size you get 2000 die, led price halves

 

[bshanahan14rulz]

Also, with defects, the smaller your chips, the smaller the percentage of chips is lost for a given number of defects.

 

[Gunner12]

Luxeon I, III, die size ~ 1 mm x 1 mm
Luxeon Rebel, 1 mm x 1 mm
Luzeon Z, ~1 mm x 1 mm (estimate from spec sheet)
Cree XR-E, 1 mm x 1 mm (EZ1000 die)
Cree XP-E, 1 mm x 1 mm (EZ1000 die)
Cree XR-C, 0.7 mm x 0.7 mm (EZ700 die)
Cree XP-C, 0.7 mm x 0.7 mm (EZ700 die)
XB-D, 1 mm x 1 mm, or 0.7 mm 0.7 mm, or 0.35 mm x 0.47 mm (DA1000, DA700, DA3547 dies depending on output and specific models)
Numbers gathered from this forum, datasheets from Cree and Philips Lumileds, and google search.

I think people are mistaking the package size for the actual die size. The thing you see in the light is the whole package, the actual LED, thermal substrates, bond wires, etc. Unless I'm completely misunderstanding the method of making LEDs, the only thing that shrunk is the package size. In some cases, the die could be smaller, like the XR-C/XP-C or some XB-D models, but those are usually rated to a lower current and generally have slightly less efficiency (higher current density, more heat per area of die).

The companies are still saving money by having smaller packages, but unless they seem to be still limited by the die's size (though 2mm x 2mm is pretty small).

 

[wa5ngp]

Do you have the size of the generic cheap LEDs that you see in a 5050 package? I've turned the current way down so I can stand to look at it but it still looks like an unmeasureable dot. I guess I should try harder again since this is an interesting point of discussion.

Does anyone know where the resistance/heat is coming from? I suppose most is from the LED semi itself, not in the gold bond wires. If its in the semi is it from the metalization? The on die metal gets pretty thin. Not sure if the big guys use copper for metalization. I'm sure the cheap stuff uses aluminum.

don