I see. So when even the very definition of what's the "top bin" is so nebulous, the very accusation may be baseless for being grossly vague.
Wouldnt the price differences - at some point - justify ordering a lower bin to increase diode count to drive more in undercurrent and get higher efficiency & other bonuses like longevity and less locale heat?
Yes. At some point. If the difference in price between an average performing diode and a top bin diode is 4c vs 8c then you could double the number of diodes and achieve efficiencies that way. Some manufacturers have already gone this route. In reality we pay maybe a 0.5c premium on LEDs that cost between 6c and 7c each. The 4c LEDs are your generic Epistars and others. It is also not as straight forward as saying you can build a light with twice as many diodes that cost half as much because the extra diodes take longer to assemble on the PCB, and PCBs generally need to be a bit bigger with more material cost. But it can be worth it and we are contemplating doing just this with some future offerings.
From an environmental point of view we believe it is better to use the most efficient diodes we can source and run them at higher currents. From a marketing perspective we have always been known for our spectrum innovation as well as efficiency so umol/j do not always tell the full story. Over 10% of the light from our boards is not counted in traditional PPFD because it falls outside 400-700nm.
Perhaps, but not necessarily. Even though voltage bin will affect flux bin, the differences in flux bin are not what I would consider negligible per se:
View attachment 5102579
The difference between 2.7V and 2.8V is 3.7%. The difference between the median of the SK and SL bins is 5.1%. The difference between the high end of the SK and low end of the SL is almost 0%.
Flux bins are not straight forward. Just because an SL bin is listed as an option in 3000K doesn't mean there is enough yield to go around. If you have a large order, there may simply not be enough LEDs to go around. You may have to wait. And remember that for every top bin diode Samsung sells, it has to find customers for another 9 lower bins. They will not produce more LEDs to give you your top bin diodes unless they are certain they can sell the rest of the production run.
Binning numbers do not tell the whole story either. If you order the SL bin, you may get 90% 38.1lm diodes. If you order the SK bin you might get 90% 37.9lm diodes. Almost no difference. I am not saying this is what happens at Samsung but when we order from Nichia, we can order binning in 1/4 and 1/2 bins as well. Here is an example of what we order.
This is the 2700K CRI90 757 series I was talking about earlier. You can read the codes from left to right: "sm273" is 3-step 2700K. "P10d22" is the upper cut of the P10 flux bin. "R9050" is CRI90.
There is a P11 bin listed on the data sheet, but in reality there are so few of these that they can't make up the numbers. So we get the next best thing which is MINIMUM upper half of the P10 bin. That means all the diodes will be at least in the upper half of the P10 bin with the remainder made up of P11 bins. P10 is 25.5-30.3lm – so we get 27.9lm minimum. P11 is 30.3-36lm. Again there are almost no diodes at 36lm so you simply can't buy them for love or money.
Here is the same diode in 3500K. These really are P11 bins which is the highest flux bin available for these diodes. We were able to get these because we needed some samples and because the 3500K diodes are made in greater numbers than the 2700K. You will also know that 3500K typically has a higher flux than 2700K. So these diodes will be between 30.3lm and 36lm each. We could try getting the upper cut of these diodes that means the minimum would be 33.1lm but there might not be enough yield for a production run.
This is a 2700K Optisolis diode which has a very high CRI98. Even though it is only P9d22 (upper cut of P9 bin) it has a much better QER, which means it throws out more photons than its flux bin indicates. Its QER (Quantum Efficiency of Radiation) is 5.1 which is very high for a white phosphor diode. A typical CRI80 3000K diode has a QER of about 4.8
While I cannot comment on HLG's business I can say with confidence that they buy many more LEDs than we do and that they appear to have a good relationship with Samsung which would make it easier to source "top bin" diodes. Or at least those that are available. Please also understand that there can be a 20% difference in flux even in within a "top flux bin". That is why we order 1/4 and 1/2 bins as well, to ensure we are at least getting "top, top" bins where available.
Again, apologies for the long post but I think it is helpful to understand this thread and how "binning" really works.
