Nichia 144A and 229A series: bigger dies, more output, 90CRI included,.......but no thermal slug :-(
Tue, 04/12/2016 - 07:47
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djozz
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Nichia 144A and 229A series: bigger dies, more output, 90CRI included,.......but no thermal slug :-(
Edited by: djozz on 04/12/2016 - 08:05
Why the fuss over no thermal pad? If they don’t need it, why do we want it? :/
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Where the specs stop, we start!
link to djozz tests
Speaking of specs, no link?
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
added a link. Still have to look at the specs but coming from Nichia they should be good. I’m at work now so I should not spend too much time on BLF
link to djozz tests
It’s a shame, if they made a 5.0*5.0 emitter with high CRI and thermal contact they would sell very well !
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Looking over the specs, the 144A is 5.0mm x 5.0mm, and compares to XHP50 in size and performance (but not the top XHP50 bin) with a single chip/die and better color rendering and lower Vf than the XHP50!
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
Well, it has 90CRI available. And again I ask why we need a thermal pad.
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
The 90 CRI version of NV4L144AM is available NOW. 3A forward current, thermal resistance only 1.2 ℃/W, 936 lm. Ideal led for a single 18650 “luxury” flashlight.
Erm, not single 18650 unless you have a boost driver. The Vf of the AM is ~6V. The AR is ~12V. Almost like they’re trying to directly compete with XHP-50…
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
A thermal pad is needed because you want to thermally connect the led to the flashlight with no non-metal obstructions, and the electrical pads can not be used for a direct metal connection. The output advantage of a direct thermal path only starts at an out-of-spec current (under 3A a XM-L2 shows hardly an advantage) and gets more when current increases.
What would work really well as a non-DTP board would be a non-DTP board like this:
(orange is the copper-poor, blue is the exposed copper for soldering)
If the MCPCB is made with an as thick copper-poor as can be produced, the heat will spread sideways fast and have then enough surface area to cross the dielectric layer efficiently. This board can be used with all the two-pad leds that are out there and boost their performance compared to the common boards.
No-one makes these, perhaps we can ask Hank to have a Noctigon version of this board designed.
link to djozz tests
Yes indeed. This looks like a drop-in replacement for XHP-50 for the upcoming ZebraLight SC600Fd III Plus.
I think getting those made is a worthy goal. I do understand that a direct thermal path is better technically. But, I haven’t seen proof that Nichia LEDs specifically suffer from NOT having the separate thermal pad. I’m sure it’s impossible to tell, since they don’t make any of their LEDs both ways (with and without DTP pad) for direct comparison. But, what if the emitters that don’t have DTP pads are designed in such a way that heat isn’t the first thing to cause failure? What if removing heat isn’t the bottleneck to performance? I know for Cree LEDs heat is definitely THE issue, but what if for the Nichias it just isn’t?
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
1. It’d be nice if it fit on a common Cree footprint so MCPCB’s were easy to come by.
2. Cree’s probably wouldn’t need a thermal pad at their rated specs either, but because they do we can overdrive them to the levels that make this hobby fun. Likewise I’m sure there is no need for a thermal pad at the Nichia’s rated specs, but it could have been much more fun if there was one. Time/testing will tell.
edit: Late post, Djozz beat me to it.
My Favorite Modded Lights: X6R, S8 , X2R , M6, SP03
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Direct XML swapping was in my mind…but I didn’t see that the Vf is 6V. It makes the swap more complicated.
Like DavidEF said, it’s more a XHP50 competitor
"-X3-, is there any place in your house without a flashlight ?"
My Flashlight public album (mods, emitter swaps, eye candy)
My reviews channel (French language, Olight, Thorfire, Sofirn, Lumintop : 60+ lights tested)
My personal channel (including Olight SR mini, S1, S2, S1A and S-mini disassembly)
M4DM4X blog, saves you $$$
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
There are ways for DTP with custom driver concepts:
a) Reverse the battery so that the body is + and can be electrically connected to LED+.
b) Use a high-side switch, i.e. a P-FET. These typically have a somewhat higher R_DS, but there are very good ones, too. LED- can then electrically connected to body (batt-).
Woa, new NICHIA emitters. Hello High CRI
Seems like that might lead to the negative side surviving and the positive side turning blue.
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So you would use short fat wires from the led into the copper star ?
And heat would go to the star ?
This would work with LEDs that also have a thermal pad. For turbo heat transfer.
Either way there can only be one connection be DTP, otherwise you would still short the led.
Or am I missing some stuff?
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I’m wondering if the cathode acts as the thermal conduit, therefore must be isolated from ground, unless you want dircect drive.
Which would work better depends on which contact of the LED has better thermal connection to the die. It could end up an advantage, because packages like Cree uses must have internal insulating layers.
Djozz’s sketch would be great if the copper is thick enough.
Flashlight designers should look at lighthouses and pottery.
这些谁设计的手电筒应该看灯塔，以及在陶器。
Why Nichia… Why?
xkcd.com/1603 Li-ion battery safety 101.
A makeshift MCPCB shouldn’t be to hard for initial testing. Just use a Cree board whose anode/cathode footprints are close and grind out a little ditch where the thermal pad is with a Dremel, so there is no contact.
Vewy intewesting!
Reminds me of Elmer Fudd hunting wabbits.
xkcd.com/1603 Li-ion battery safety 101.
If they did a good design and uses the two main contact pads are the thermal conductors then the center pad should not be really needed. ( i guess most of us are used to having the center-pad on Cree emitters to match Noctigon stars, and like to over-drive LEDS to near burn-out. as long as the die, substrate, and two thermal/contact pads are designed well, and we have a good noctigon designed for these LED then where won;t be a problem.
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So, if there is a dielectric layer under the electrical traces, how will a Noctigon help? This will be just like all the old Cree boards that have lesser thermal characteristics. The heat being dissipated through the trace pads will still have to go through the dielectric layer and as such, will be slowed down. This is ok if you don’t overclock, not at all conducive to most of us modifying flashlights.
Yeah, DTP stars are pointless if you’re not using the DTP! Best bet would be to make a board like djozz showed, with thick and large copper pours, and use the fancy nano dialectric layer that supposedly has a high thermal conductivity.
The Cycle of Goodness: “No one prospers without rendering benefit to others”
- The YKK Philosophy
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