I had an unusually pleasant interaction with an LED manufacturer lately - I had some custom LEDs made!
I have been using some Chanzon LEDs in my projects lately (find them on Amazon, Ebay, or AliExpress). They have two different chip sizes (30x30 mil and 45x45 mil) they package into various cases. Here are images of their "1W" and "3W" red LEDs, which consist of the two different chips in the same package:
I didn't quite figure out how the 3W chip has only 2.25x the area of the 1W chip - anyway, little chip = less power, big chip = more power.
Now, I'm working on a project where I need some really bright, really short flashes of red, green, and blue light. Like 100A of current for sub-microsecond pulses into a handful of LED chips. Chanzon makes a 10W LED in a larger package with a 3x3 array of the smaller 1W chips, but what I really would like is an array of the larger chips. After seeing how manual the LED assembly process actually is in the Sparkfun article (a really good read):
I figured they might be able to make some custom LEDs - just plop the larger chips where you usually put the small ones. A week of back-and-forth messaging on AliExpress, and we had it all sorted out. The custom parts arrived today:
The custom part is on the right with the larger chips; the normal part is shown on the left. Of course, if you actually ran these LEDs at 30W continuously, they'd easily overheat and fail. Driving them in pulsed mode with very low duty cycle will allow some extremely bright flashes.
I'm still amazed I was able to have these made. The only other custom parts I've used have been inductors or transformers I've wound myself. Having a manufacturer accommodate a small (10x of three colors) custom order like this is unbelievable. And just plain awesome.
If you look very carefully at the top left LED in the array above, you can see it's missing a bond wire. Here's a close-up (same orientation):
I just put all 30 of them under the microscope...and this is the only one with the defect (I was just lucky to pull it out for pictures yesterday). Electrically, it still tests out OK, because one bond wire is present. I just wouldn't trust this particular unit with high-current pulses. Still a heck of a deal.