I have a Noctigon 20mm heat sink like in this picture:
and I want to solder a Cree XP-C on to it. Does the orientation of the XP-C matter? Can I put it on pcb in any orientation?
This is what I have done so far:
Is this right or does the heat pad is not even right for an XP-C?
Wrong pcb for that led. That’s an XM Noctogon, you need an XP Noctogon that has solder pads sized to fit an xpg led or an XM led for that Noctogon.
The noctigon you actually used is an XM. For XM-L, XM-L2 or other XM leds.
See at the top it says “XM” and the first picture says “XP” instead?
And once you get the right sized noctigon, the orientation does matter.
That’s the correct orientation though. 180 (squares on bottom ) puts the plus side of the led on the right. 90 (either way) puts the led contacts across all the pads creating a short.
Not the right MCPCB for the XP-C, looks like an XM-L board.
The two outer silver bars are positive & negative and the middle pad is for heat dissipation
So you want things to line up like this
Thank you all guys for the quick response. I knew something was not right and I thought posting a thread here would be the way to find out. I actually have the following three LEDs, XP-C, XT-E and XR-E. I found a Noctigon mcpcb for XP at mtnelectronics. That should work for the XP-C, right?
What about the XT-E and XR-E, where can I buy mcpcbs for those, preferably copper ones?
XRE might fit on a mtg pad. As far as I know it’s been supplanted by newer LEDs so no copper boards for it.
Also, XRE is one of the few LEDs that you can sand the +/- pads off the bottom of and solder wires to the top of.
The Noctogon XP should work with any Cree XP including C, E, G, L, and also Nichia 219, (A,B).
Careful telling people that it will work with Nichia emitters, without also telling them that the thermal pad will have to be ground out or covered over in order to not short out, since Nichia’s don’t have a thermal pad. 
Omg, poor thing, what have you done to it 
All of mine do. Are you thinking of 119’s?
Overheated it on the hot plate. It was my first attempt of soldering a LED to mcpcb 
The xte will also fit but has a much higher thermal resistance so you won’t be able to drive it as hard. This Cree page has links to each of the Cree LEDs with data sheet PDF’s for each that include all the info. Pad sizing is located at the end of each PDF.
i soldered prbly hundred of leds using simple gas stove, and tiny 5” frying pan.
I’ve used a soup can lid. Anything will do that buffers the heat source and prevents the flux from seeing direct flame. I use a small butane torch now over 1/16” sheet aluminum for better control and so I can view it through my magnifying lamp.
It is still not clear which thermal pads are good for XT-E and XR-E LEds and also where to buy them?
XTE fits XPG pads, XRE copper stars aren’t made but you might be able to sit one on an mtg star. The mtg pads are similarly spaced but longer in length so the XRE might not self center.
At least a XR-E fits on a MT-Noctigon copper board, but it does not profit much from the fancy copper board because it sheds the heat well enough on a convential aluminium board (I tested that).
But why using a XR-E? There is nothing about it that is not better in more modern leds.