# Cree XP-G on 8mm MCPCB



## Geogecko (Mar 18, 2013)

Any place I can find these, prefabricated? I've looked into doing it myself, and just don't think I want to get that involved... Only thing I've been able to find them on is 10mm boards. This would be used to modify a McLuxIII-PD.


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## Mattaus (Mar 18, 2013)

I checked my usual sources and your best bet would likely be getting a 10mm MCPCB and filing it down to 8mm.

Next step after that is designing and having your own manufactured 

Sent from my Galaxy Nexus using Tapatalk 2


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## tobrien (Mar 18, 2013)

maybe this? http://theledguy.chainreactionweb.com/product_info.php?cPath=48_49_63&products_id=1251

or are the XP-E and XP-G different area requirements?


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## Mattaus (Mar 18, 2013)

XPG and XPE footprints are interchangeable so they will work fine.


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## Geogecko (Mar 18, 2013)

I was looking for XP-G, as I think it will be a better suited LED for the PD, based on what I've read. Will provide a larger spot (wider angle) than the XP-E.

Seems difficult to find the G on an 8mm board though, may just have to do it myself...or try and file a board down.


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## tobrien (Mar 19, 2013)

Geogecko said:


> I was looking for XP-G, as I think it will be a better suited LED for the PD, based on what I've read. Will provide a larger spot (wider angle) than the XP-E.
> 
> Seems difficult to find the G on an 8mm board though, may just have to do it myself...or try and file a board down.



try out the link I sent you. the Sandwich Shoppe is, as you may know, a CPF store and the XP-E's and XP-Gs have the same footprint as Mattaus stated and Cree's site confirms


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## louie (Mar 19, 2013)

I've been using the Sandwich Shoppe 8mm MCPCBs for XP-Gs and Nichia 219s and they work fine. A good time to learn to reflow. However, the resulting height is much shorter than the old Luxeons, and you'll have to experiment with shims of some sort. Myself, I found my applications (HDS EDC) worked fine by using a second 8mm MCPCB underneath as the shim. Heat transfer appears to be fine.

Illumination Supply shows an 8mm MCPCB, but it's always out of stock when I look.


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## Geogecko (Mar 19, 2013)

Thanks Louie. It appears Illumination Supply has the 8mm MCPCB's in stock. Is the Nichia a better choice than the XP-G? I see it's a little higher CRI and possibly higher output, at least, this one appears to be.

https://illuminationsupply.com/nichia-nvsl219ath1-4500k-92-cri-b10-bin-bare-p-161.html

So how did you attach your MCPCB's together, and then to your HDS?

What did you use to do your reflowing?

Looked at a Luxeon III datasheet, and the LED is 5.86mm tall. The Nichia is 2mm tall, so two boards would put it at about 4mm tall. You think 3-4 boards would be necessary to get it to the right height?


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## louie (Mar 21, 2013)

Geogecko said:


> Thanks Louie. It appears Illumination Supply has the 8mm MCPCB's in stock. Is the Nichia a better choice than the XP-G? I see it's a little higher CRI and possibly higher output, at least, this one appears to be.
> 
> https://illuminationsupply.com/nichia-nvsl219ath1-4500k-92-cri-b10-bin-bare-p-161.html


I like the high CRI, and the Nichia at 92CRI and 4500k is similar to daylight. The XP-G hi CRI at 90CRI is yellow like an incandescent. Other XP-Gs in other color temps aren't nearly as high CRI. It's personal preference.



> So how did you attach your MCPCB's together, and then to your HDS?


I just put a little thermal paste (Arctic) in between the MCPCBs and on the HDS mounting hole and pressed down firmly. I wanted to be able to test the height and the XP-G vs. Nichia. It seems to transfer heat just fine - the light gets nice and warm when on max for a while, and doesn't shut down prematurely. However, the current is modest, probably around 1A. If I were more paranoid, I might use Arctic epoxy now that I am satisfied with the alignment.


> What did you use to do your reflowing?


I use a travel clothes iron clamped upside down (flat side up). It has adjustable heat and seems to be working fine for me. I posted about it here: 
http://www.candlepowerforums.com/vb...pe-for-led-s&p=4138405&highlight=#post4138405



> Looked at a Luxeon III datasheet, and the LED is 5.86mm tall. The Nichia is 2mm tall, so two boards would put it at about 4mm tall. You think 3-4 boards would be necessary to get it to the right height?


Total height is irrelevant, it's where the die sits. In my HDS, I tried no shim and 1 MCPCB shim, which was as high as it could go in this light, and it works very well with the existing reflector. I could have done multiple experiments with other shims, but I'm far too lazy.

I may have bought some Illumination Supply 8mm boards, I have some of their other boards - I don't know if I figured out what the thickness of their 8mm is. Usually the given specs for thickness are nominal. I can look when I am at home. I also have some Sandwich Shoppe copper discs for shims.


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## Geogecko (Mar 21, 2013)

Thanks for all the replies. I'm going to go with a neutral XP-G2. I love the travel iron with regular solder setup. Pretty impressive.

I think I'm going to have to pick up a few boards and LEDs to play with, and maybe see if I can find an old iron somewhere...


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## louie (Mar 21, 2013)

I looked thru my stock, and I only have 8mm XP-E/G MCPCBs from the Shoppe. They're 0.85mm thick as measured. I've never seen the Ill. Supply 8mm boards.

If you search for homebrew reflow methods, there are a lot out there.


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