6x 20mm XML-ledboard comparison

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nikanon
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Thank you Sir ! :hat:

Hikelite
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Pulsar13 wrote:
nikanon wrote:
Thank you for this test and the well presented results even a non-tech person like me can understand easily. I got one question, how good/bad will a 20mm noctigon board perform in comparison to the sinkpads ?
About the same. From our members' tests, pretty sure we can establish now that the limiting factor is almost always the dielectric layer. Once that factor is taken out, even aluminium base gives performance not too far from Noctigon/Sinkpad.

According to these high end tests  there basically no difference.

 

 

 

welight
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There is a new MCPCB with a Diamond like dielectric structure. The dielectric functions like graphite which is used by high end fixtures manufacturers as a thermal pad, in that it spreads heat both vertically and horizontally and can provide performance of copper PCB, in a ALU PCB

Cutter Electronics Pty Ltd
Web: https://www.cutter.com.au

M4D M4X
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do you have a link?

PLEASE NOTE
i do not work in "reviews, deals and codes" for the time being
maybe M4D M4X will return one day, but until then:

THANK YOU FOR YEARS OF YOUR SUPPORT AND FRIENDLY CONTACTS!

djozz
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welight wrote:
There is a new MCPCB with a Diamond like dielectric structure. The dielectric functions like graphite which is used by high end fixtures manufacturers as a thermal pad, in that it spreads heat both vertically and horizontally and can provide performance of copper PCB, in a ALU PCB(cheaper)

That is good news for the emitters without electrically neutral thermal path, like the Oslons Smile

Nightbird95
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Copper MCPCB Mod finally completed. Wink

Thanx djozz for your tests. Beer

Gj
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Interesting results, thanks for the detailed tests.

 

WarHawk-AVG wrote:
Yeah, appears that way, so by the time it got to 3A it had already been "cooking" for a bit, even longer at higher currents...so the heat sag wouldn't be an issue with the readings...nice! So do you think it's cost effective to get sinkpad over the cheap FT copper stars and cut out the dielectric layer, or just too much hassle

I think where this is most valuable is in modifying those oddball size stars that Sinkpad and Noctigon don't have, 25mm in the Aleto 26650, 32mm in (I forget what). Maybe even triplet/quad boards?

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Hikelite wrote:

Pulsar13 wrote:
nikanon wrote:
Thank you for this test and the well presented results even a non-tech person like me can understand easily. I got one question, how good/bad will a 20mm noctigon board perform in comparison to the sinkpads ?
About the same. From our members’ tests, pretty sure we can establish now that the limiting factor is almost always the dielectric layer. Once that factor is taken out, even aluminium base gives performance not too far from Noctigon/Sinkpad.

According to these high end tests  there basically no difference.

 

 

 


Huge difference between direct heat path and one with the dielectric layer though
welight
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M4D M4X wrote:
do you have a link?

the basic details are below. a comparative guide between normal dielectric and the DLC

email me if you want details

Cutter Electronics Pty Ltd
Web: https://www.cutter.com.au

Helios-
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Excellent djozz. Thank you.


Counterfeit 18650s, 2,<a href=“http://

WarHawk-AVG
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welight wrote:

M4D M4X wrote:
do you have a link?

the basic details are below. a comparative guide between normal dielectric and the DLC

email me if you want details

nice graphic

I find these are helpful too

M4D M4X
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thanks

PLEASE NOTE
i do not work in "reviews, deals and codes" for the time being
maybe M4D M4X will return one day, but until then:

THANK YOU FOR YEARS OF YOUR SUPPORT AND FRIENDLY CONTACTS!

leaftye
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welight wrote:

M4D M4X wrote:
do you have a link?

the basic details are below. a comparative guide between normal dielectric and the DLC

email me if you want details

Looks useful.  I hope you'll send samples to one of our members for review.  Relic38 has done some nice reviews.  Hopefully he'll be up for testing this too.

A couple questions though.

How can I tell from your webpage if a mcpcb is using DLC?  Will a triple XM-L board be made? 

The low mode should be lower.

djozz
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Looks very promising but, as usual in marketing, the 'old' type board is drawn to perform worse than in reality; the heat when entering the aluminium core of the board will go circular in all directions, not just downward, as the drawing suggests.

In any case, I think the major bottleneck was already overcome by the direct-bond-to-copper-boards, I do not expect a performance improvement as high as when Sinkpad boards entered the market. But the electrical insulation between thermal pad and core is a really useful feature!

Hikelite
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djozz wrote:

Looks very promising but, as usual in marketing, the 'old' type board is drawn to perform worse than in reality; the heat when entering the aluminium core of the board will go circular in all directions, not just downward, as the drawing suggests.

In any case, I think the major bottleneck was already overcome by the direct-bond-to-copper-boards, I do not expect a performance improvement as high as when Sinkpad boards entered the market. But the electrical insulation between thermal pad and core is a really useful feature!

Exactly!

All Copper boards can be enhanced to distribute heat better (not really needed), like all AL normal boards have the thermal trace as wide as the boards. For some reason on direct thermal path they decided not to them like that.
I do not see them actually work better than direct thermal pad boards which clearly cannot take advantage of the 390W/m.k of the cooper when you can see Aluminum boards rated at 135W/m.K performing as the 390W/m.K copper boards.
So what I mean that wide spread can be done with normal copper direct thermal path, especially for single LEDs on 20mm.

Tom E
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djozz - Excellent info, great job on this! Lots of time and some cost I'm sure...

Question - didn't see it mentioned, what was the time lapse on your measurements? For example, was it pretty much instant once the amps was set to the point of reading the lux meter? Wondering if under-lying these stats is the dimension of time - what's the instant reading vs. 10/30/60 seconds of runtime. Of course it would take long collecting all the data pts, but would be interesting to know if the copper MCPCB's show any advantage over aluminum.

welight
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Hikelite wrote:

djozz wrote:

Looks very promising but, as usual in marketing, the 'old' type board is drawn to perform worse than in reality; the heat when entering the aluminium core of the board will go circular in all directions, not just downward, as the drawing suggests.

In any case, I think the major bottleneck was already overcome by the direct-bond-to-copper-boards, I do not expect a performance improvement as high as when Sinkpad boards entered the market. But the electrical insulation between thermal pad and core is a really useful feature!

Exactly!

All Copper boards can be enhanced to distribute heat better (not really needed), like all AL normal boards have the thermal trace as wide as the boards. For some reason on direct thermal path they decided not to them like that.
I do not see them actually work better than direct thermal pad boards which clearly cannot take advantage of the 390W/m.k of the cooper when you can see Aluminum boards rated at 135W/m.K performing as the 390W/m.K copper boards.
So what I mean that wide spread can be done with normal copper direct thermal path, especially for single LEDs on 20mm.

The reality is copper as a base substrate has better thermal performance than ALU. The issue has always been the dielectrics which are generally high in fibreglass are the issue and direct thermal pads make a big difference. This is more an exercise in replacing the dielectric to make ALU boards a better performer relative to copper as ALU is a lower cost product. I have some initial samples of a multi led XML PCB, happy to donate for test?

Cutter Electronics Pty Ltd
Web: https://www.cutter.com.au

djozz
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Tom E wrote:

djozz - Excellent info, great job on this! Lots of time and some cost I'm sure...

Question - didn't see it mentioned, what was the time lapse on your measurements? For example, was it pretty much instant once the amps was set to the point of reading the lux meter? Wondering if under-lying these stats is the dimension of time - what's the instant reading vs. 10/30/60 seconds of runtime. Of course it would take long collecting all the data pts, but would be interesting to know if the copper MCPCB's show any advantage over aluminum.

The costs were mainly my new power supply. I bought it to do these kind of measurements, and it performs really well. With my old one I could not have done these kind of tests, it does not go over 7 amps, and setting a current is a pain. The new one adjusts really easy and goes up to 20A. I prepared some things beforehand (like initial testing out the power supply and test-leads, and removing the dielectric layer on one of the boards). But the actual tests were done in one session lasting an evening and part of the night.

The time lapse was mentioned, but not in the OP (should have been there). I started each test at 0.5A, going up 0,5A each time and recording voltage and lux, up to 7A. After each rise I waited 10 seconds and then recorded V and lux, I think the led was at each current for about 25 seconds total, but the starting point for each new current of course was only 0.5A less. Indeed if I had waited much longer to let it settle more, the whole test-series would taken more time than I was happy to spend on it (my hobby is squeezed in between work and family, I have to admit both suffer from it, but I just need to have a hobby), but looking at the luxmeter during the tests I never (also not at 7 amps) saw fast declining numbers signifying an unstable siuation, (typical example: when a reading at 10 seconds was 702 lux, at 20 seconds it would be 700, and that did not worry me).

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Interesting.... Copper has such a small effect on output and thermal sag over aluminum? Hhmm.... Our custom made copper pills have more volume of metal than the stock pills, so the measured differences may be more related to total mass/volume as opposed to the source material, I suppose.

Then I'm a bit stumped. Where is that thermal performance advantage of copper going to? It's there I suppose, but such a small factor only at higher amps/temps.

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welight wrote:

Hikelite wrote:

djozz wrote:

Looks very promising but, as usual in marketing, the 'old' type board is drawn to perform worse than in reality; the heat when entering the aluminium core of the board will go circular in all directions, not just downward, as the drawing suggests.

In any case, I think the major bottleneck was already overcome by the direct-bond-to-copper-boards, I do not expect a performance improvement as high as when Sinkpad boards entered the market. But the electrical insulation between thermal pad and core is a really useful feature!

Exactly!

All Copper boards can be enhanced to distribute heat better (not really needed), like all AL normal boards have the thermal trace as wide as the boards. For some reason on direct thermal path they decided not to them like that.
I do not see them actually work better than direct thermal pad boards which clearly cannot take advantage of the 390W/m.k of the cooper when you can see Aluminum boards rated at 135W/m.K performing as the 390W/m.K copper boards.
So what I mean that wide spread can be done with normal copper direct thermal path, especially for single LEDs on 20mm.

The reality is copper as a base substrate has better thermal performance than ALU. The issue has always been the dielectrics which are generally high in fibreglass are the issue and direct thermal pads make a big difference. This is more an exercise in replacing the dielectric to make ALU boards a better performer relative to copper as ALU is a lower cost product. I have some initial samples of a multi led XML PCB, happy to donate for test?

That sounds great.  Either djozz or relic38 would be great.  Djozz didn't mention it in his post at the top of this thread, but he also stress tested a direct bond copper mcpcb for the Cree MT-G2.  I think it'd be great if you could send samples to both testers if they're up for it, especially of that multi XML board since that may offer something that no one else does.

The graphic is a bit disingenuous, but it's minor compared to the results of independent testing.  If the results are good, I'll be posting the test results in this forum and at least one other, not that misleading graphic.

The low mode should be lower.

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I would think a thermal imaging of the emitters on the stars, with and without dielectric aluminum vs copper would be a good comparison

Heck I would like to see some of the homebrew budget mods on test as well (the ones where they drill out the aluminum under the star and install a copper slug from a wire)

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Tom E wrote:

Interesting.... Copper has such a small effect on output and thermal sag over aluminum? Hhmm.... Our custom made copper pills have more volume of metal than the stock pills, so the measured differences may be more related to total mass/volume as opposed to the source material, I suppose.

Then I'm a bit stumped. Where is that thermal performance advantage of copper going to? It's there I suppose, but such a small factor only at higher amps/temps.

It's a head scratcher, especially that dielectric that performed surprisingly well.  As far as the metal of the pill and flashlight, I think it comes down to emissivity.  I bet the best combination is something like this.

WarHawk-AVG wrote:
Absolutely gorgeous job! Love the chamfer and riveting approach Excellent job as always comfy! All done with a drill press? Reminds me of those copper core aluminum heatsinks for CPU's !http://www.frostytech.com/articleimages/200706/intelC2Dstock_nofan.jpg![...

Use copper to quickly absorb lots of heat and conduct it to a layer of aluminum with lots of surface area.  Maybe the current set up is good enough not to suffer significant sag, but this concept should increase comfort.  Where lights typically only get warm around the pill, a longer copper sleeve would spread the heat more evenly throughout the body, which should decrease the heat felt at any particular area since there's more surface area of aluminum to dissipate the heat.  Increasing contact area is already something lots of you guys do with P60's...and I'd do it too if I had any of those.  

The low mode should be lower.

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Don’t underestimate the heat SINKING properties of aluminium compared to copper.
You can put much more heat in a given mass of alu than in the same mass of copper, before it actually gets hotter / warmer.

djozz
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Jerommel wrote:
Don't underestimate the heat SINKING properties of aluminium compared to copper. You can put much more heat in a given mass of alu than in the same mass of copper, before it actually gets hotter / warmer.

I have tried to explain that one before, but there is the widespread misconception that more mass means more heatsinking. If you compare copper and aluminium by volume (that is what you do in practice when you swap aluminium parts for copper parts) the copper part does win for storing heat, but only by a factor 1.4 compared to aluminium (while it is 3.3 times as heavy).

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I didn’t know copper is better per volume as a sink !?
Thanks.

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djozz wrote:

Jerommel wrote:
Don’t underestimate the heat SINKING properties of aluminium compared to copper. You can put much more heat in a given mass of alu than in the same mass of copper, before it actually gets hotter / warmer.

I have tried to explain that one before, but there is the widespread misconception that more mass means more heatsinking. If you compare copper and aluminium by volume (that is what you do in practice when you swap aluminium parts for copper parts) the copper part does win for storing heat, but only by a factor 1.4 compared to aluminium (while it is 3.3 times as heavy).

1.4 correlates well enough with this data.

I don’t think we should emphasize mass too much, volume is the factor is most cases, unless you’re flying it to space or something. So copper still have the edge hands down in most applications.

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Tom E wrote:

Interesting.... Copper has such a small effect on output and thermal sag over aluminum? Hhmm.... Our custom made copper pills have more volume of metal than the stock pills, so the measured differences may be more related to total mass/volume as opposed to the source material, I suppose.

Copper pills are highly overrated. Unless you believe in them. There seems to be many believers though. The measured differences are usually between zero to minor depending on the current in a typical XM-L2 hotrod build..  In a fully hotrodded MT-G2, there is more gain, due to having up towards 3-5 times as much heat going through the MCPCB and into the pill, but even then. Not really noticeable by eye..

If id had not been for the copper hype here on BLF, the difference between the best copper and aluminium MCPCB would`t be as shocking to some..

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http://budgetlightforum.com/node/19342

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'Copper is better than ___!!!' has turned into some kind of cargo cult.'But I build all my lights with copper everything, and they are all really bright, therefore if you want it to be bright you have to use copper!'

The numbers just don't back up what you find in those thermal conductivity charts. They're irrelevant.

Hikelite
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We've kind of blasted brass as being the worst thing possible, now sinkpad uses a 135W/m.K rated aluminum for those boards, most likely 5052 which is the most common specified alloy in alu MCPCBs, now we have the "poor" common brass at 125W/m.K....

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Is there a chart anywhere that shows how many lumens per W/mK? No? Why not?

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