# Sinkpad MCPCBs: Any good?



## anuragwap (Oct 13, 2012)

EDIT: Sorry for the deleted posts guys. I wanted to know if anyone here had used this product. It is advertised to be better than the regular MCPCBs. That means we could use lighter heatsinks if we used sinkpads. Unfortunately they don't have any distributors. You must order your sample directly from them and hobbyists like me probably don't stand a chance. No idea about cost either. As far as I recall, I linked this Youtube video.




EDIT: I got 4 free samples for luxeon rebels. Cheers to sinkpad for helping a hobbyist!


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## bshanahan14rulz (Oct 15, 2012)

These are MCPCB with direct thermal connection between slug pad and the metal core. 


> In essence SinkPADTM PCB technology provides Direct Thermal Path to the LED by eliminating dielectric from the thermal path.


http://www.sinkpad.com/what-is-sinkpad.php


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## tstartrekdude (Oct 15, 2012)

They look really nice, much better than the crap normally used. Basically it seems like they are just adding a solderable layer right onto the metal slug. In all my looking though I couldn't find anywhere to buy them.


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## anuragwap (Oct 15, 2012)

Deleted!


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## bshanahan14rulz (Oct 16, 2012)

led-tech.de has similar products, but with the LEDs pre-mounted, and from memory all I remember seeing offered was the XM-L. Copper MCPCB with direct access to the copper core for the thermal pad.


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## anuragwap (Oct 16, 2012)

Deleted!


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## bshanahan14rulz (Oct 17, 2012)

They use AA because it is hard to correctly solder an LED to a (relatively) giant chunk of aluminum. Saabluster likes to solder his emitters to copper blocks, IIRC. Best way to think of MCPCB is as a quick way to soak up heat from the high concentrated heat of the thermal pad. In order for it to keep working well, a heatsink must be attached. Kind of like processors now. You know how CPUs used to be the silicon chip mounted on some multi-layer fiberglass board with lotsa pins under it, and then they switched to packages where the silicon chip was covered with a big square of metal, a heatspreader.


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## alpg88 (Oct 17, 2012)

you can't solder to aluminium, that is why ppl use AA.
i build few p7 lights where i glued led directly to the anodized heatsink, p7 had big thermalpad, very easy to glue ,


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## bshanahan14rulz (Oct 17, 2012)

I believe in order to solder to aluminum, you would have to use either a special flux, or a special solder paste made with that flux.

The flux is heat-activated and removes the alumina chemically. The solder then is able to wet the underlying metal before the flux boils off and the aluminum oxidizes with the air again.


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## alpg88 (Oct 17, 2012)

bshanahan14rulz said:


> I believe in order to solder to aluminum, you would have to use either a special flux, or a special solder paste made with that flux.
> 
> The flux is heat-activated and removes the alumina chemically. The solder then is able to wet the underlying metal before the flux boils off and the aluminum oxidizes with the air again.



good, now try to solder a led to aluminium heatsink, so it works afterward, than tell us how it went


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## anuragwap (Oct 17, 2012)

Deleted!


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## bshanahan14rulz (Oct 18, 2012)

Yeah, I hear where you're coming from. Like I said with my CPU example, there must be some merit to the bonding technique they use between the integral heatspreader and the cpu die being done at the factory, as opposed to the less-than-robotical precision of the application of thermal paste and a heatsink applied directly to the chip by end users. 

And on the example of that fella' who reflowed emitters directly to the heatsink, not only is soldering to aluminum an issue, but also keeping your LEDs relatively cool while you are trying to get the heatsink back down to a safe temperature can be an issue, and you would never know because perhaps you bought an R3 XP-E, but due to heat damage, it may have degraded to perhaps Q5 levels, but by eye you'd have a hard time noticing that.

On top of that, MCPCBs are easy, and leave less of a chance of a screw-up by the "end user" who thermally bonds the MCPCB to the heatsink, and it is easier to follow the LED manufacturer's guidelines on how much heat the LED can handle during soldering and still stay within spec when reflowing to something like an MCPCB that doesn't have the thermal mass of a heatsink.

So, basically, if you can find an MCPCB for your application that allows you to solder directly to the metal core for the thermal slug, I think that would be the best balance between ease of assembly, safety for the LED, and performance.

@alp: Unfortunately, that would do us no good because I don't have the equipment to quantify the results. LEDs can be damaged by heat, whether that heat is coming from them or an external source. It just needs to be shown what sort of losses we can expect from various extended heating times for particular types of LEDs.


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## Direct Thermal Path (Jan 28, 2013)

You dont need to worry about how to solder thermal slug of an LED directly to the Aluminum because SinkPAD has developed special deposition process where aluminum pad is already solderable at each LED locations, See central pad in attached image. All you have to do is use normal assembly steps to assemble LED onto SinkPAD MCPCB and LED will get "Direct Thermal Path" to the metal. no more thermal resistance of a dielectric that you see in a traditional MCPCB. This has reduced anywhere from 5 to 25 degree Celsius in LED junction temperature. 


*See Rule #3 Do not Hot Link images. Please host on an image site, Imageshack or similar and repost – Thanks Norm*


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## Erdin (Mar 20, 2014)

HI are the LED soldered onto the sinkpads or glued? also is there a link that exoplaines it. sorry if it sounds like a dum question but i havent done this befor and i just orded a LED that will needed atteching to a sinkpad.:duh2:


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## alpg88 (Mar 20, 2014)

they are soldered, google led reflowed on a star, and you'll see videos how it is done, very simple procedure, i do it on a tiny frying pan, and gas oven.


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## Erdin (Mar 20, 2014)

alpg88 said:


> they are soldered, google led reflowed on a star, and you'll see videos how it is done, very simple procedure, i do it on a tiny frying pan, and gas oven.



Thanks alpg88, that's very helpful.


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## m4a1usr (Mar 21, 2014)

Erdin said:


> HI are the LED soldered onto the sinkpads or glued? also is there a link that exoplaines it. sorry if it sounds like a dum question but i havent done this befor and i just orded a LED that will needed atteching to a sinkpad.:duh2:



If you plan on doing builds as a hobby I would recommend you get a good heat gun for doing the job. A decent clamping vise to hold the work and a heat gun make attaching any LED to a MCPCB the simple and easy job. I actually even enjoy doing them since it allows for good quality control.


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## Erdin (Mar 22, 2014)

m4a1usr said:


> If you plan on doing builds as a hobby I would recommend you get a good heat gun for doing the job. A decent clamping vise to hold the work and a heat gun make attaching any LED to a MCPCB the simple and easy job. I actually even enjoy doing them since it allows for good quality control.



Hi thanks for the reply, I have a heatgun so will give it a go once the pads arrive.


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## langham (Mar 22, 2014)

My 2 cents yes, they are good. They are a lot more expensive than Noctigon though and from my experience not much better. You can decide for yourself based on what you have seen, but I have bought and used both and I like them about the same only difference being the insane price difference.


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## langham (Mar 22, 2014)

I have a few samples that I got directly from Sinkpad. They will only distribute aluminum samples so I had to buy the copper ones. If your question has to do only with if this type of product is worth it then I will say absolutely. That is how you can drive an led that is rated for 1A at >2A and not destroy it. You simply directly copper mount it. This will allow you to have a thermal path that has twice the thermal conductivity of the manufacturers test substance which is aluminum. Take a close look at the spreadsheet for lets say Cree leds and you will notice a section that talks about thermal properties. You will notice that the better your thermal path is the more light you will get for a given drive current vise versa you can have a higher drive current and not kill the led. The heat damage thing is an issue, but if you use copper it will typically cool down so quickly that it will not be an issue because it is thermally mounted the die will only be greater than specs for a moment.


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## pepperdust (Mar 27, 2014)

very much worth it..

I have a li-cor, and did testing.. these produce more light.. the higher you drive, the better they become..

second, this was testing DIY reflow, vs "pro reflow" .. had 18 of each


have the copper also, but didn't test, as I know it makes more light, there was some graphs here or some other place showing the performance of the sinkpads

also thanks for the noctigon info.. never heard of them.


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