Henry, you know where to get them, stop playing games with us.
Here’s some of what I was thinking about, when encompassing the “high” forward voltage changes we are seeing over time, and just general LEDs we are seeing as time moves ahead. It’s important to look at another industry to understand where I’m leading.
If you think about the core technology driving the common white phosphor-LED, most know what it is. I think just a grade of silicon semiconductor, just like Intel and AMD use to do processing with computer chips—with LED silicon arranged to do a much different type of work when made. If you think about the core “product” in these LEDs that can make them potent for throwing, then, it’s really not the phosphor, the bond wires, or the domes really; the “nuts and bolts” are the same between most of the MFGs. Manufacturers are capable from what we’ve seen, of making near identical components like those, and arranged how they want them. I would ask what it is that they (LED makers) cannot completely control, then, and again I think of the semiconductor.
Silicon semiconductor wafers are usually something a large company buys from another large company who specializes in the production of intricate, advanced semiconductor growth through advanced methods of stereo lithography types of production. The LED maker implements that final chip somehow into their product as they see fit, to do its job as they see fit, which includes handling heat dispersal methods. The silicon itself has much different standards than the rest of the LED, but likely similar in many.
It would not surprise me then, if some LED makers used the same exact silicon wafer material in their LEDs.
This is also why I brought up the ‘quantum wells’ looking similar, or the “holes” you see in an LED die surface now instead of line traces—between Cree and Nichia.
Have you ever heard of Moore’s Law? Take a look at computer processors of recent years. “(Moore’s Law)”:Moore's law - Wikipedia It’s not an actual law, but it, for the most part held true for a very long time as a ratio to product.
Then silicon makers started meeting the end of a dark tunnel; they were getting close to exceeding the trace limit width, defined in our physical world by the size of a few atoms. Talk of this started happening as far back as 2010. We cannot break this law, fundamental to nature, or make something smaller than an atom. Computer processors adapted, instead of increasing transistor count by making the chips smaller with more micro transistors and traces, they condensed more CPU chips into one piece of silicon, creating larger, multi-core processors, that weren’t actually smaller inside; the overall package and footprint remained the same. It was like taking a Prius car, and combining 4 of their engines, but still inside one Prius. The “engine technology” is there which is efficient and now, and power still grows. Oh well, Moore knew his ‘law’ had to have an end someday.
Someone mentioned on BLF the fact that chips have gotten bigger, brighter, but for this many years to go by, surface intensity has not increased exponentially above the old XR-Es we would likely have expected back then while predicting forward.
If you feel this same sort of parallelism between silicon makers, it tempts me to believe the LED world is running down that same tunnel. They can get the silicon to do a little better, and a little better some more, but to get the lumens they need, they went to mutli-chip use instead of driving up the intensity, regulated by the silicon semiconductor inside. I believe we will see LEDs stop at their current sizes, and possibly start to grow outward. This is even showing by Cree claiming new intensity, by simply applying little dome material. If they could, the dome would stay, and we would see those big intensity gains. The market isn’t calling for it. Efficient chips, with high L/W are needed.
My point with all this is not a great one, I just think it might offer some explanation as to why we are seeing things that make us flashlight users frown at times, like high Vf.
So unless everyone out there forgets about flood right now, starts buying aspherics, and showing what a sucker they are for big THROW, Cree simply isn’t going to pay any attention to us. Ha, if only… :bigsmile: