INTL-OUTDOOR Direct-Thermal Copper MCPCB Review

About the time that everyone caught wind of the International Outdoor Copper MCPCB for XM-L and XP-E/G, Hank from International Outdoor got in touch with me and asked if he could send me a couple of them to review. I agreed.

These are pre-production versions, and I understand that that silk-screen markings on them will be changing, but otherwise they’re the same as what one would expect to be able to buy later this month.

These were sent to me at no cost by Hank - just for full disclosure.

So, Here’s the MCPCB. Direct Thermal Attach with no insulator between the base material and the thermal pad on the LED. Copper is very lightly gold plated to prevent tarnishing. Surprisingly, the bottom side of the PCB is also gold plated which is great!

The top of the electrical pads is perfectly planar with the top of the center slug - as should be expected.

On one of the samples I received, I cut away the insulation layer to expose the base copper. This shows quite nicely how the center thermal slug is solid copper rising out of the base.

On some MCPCBs, the insulating layer is not very well attached to the base copper, and it can detach itself during the extreme heat of reflow. I heated the whole MCPCB up to 250 degrees C and used a sharp blade to try and separate the layers of the PCB. I was unsuccessful. The layers of the PCB are very well joined together.

The footprint for the XM-L is perfect with the proper solder mask openings to allow excess solder to escape - this helps to assure that all three connections are made without the emitter floating too high off of the MCPCB.

The samples I received are 15.93MM in diameter, the base copper material is 1.25MM and the overall thickness is 1.5MM. The back side of the MCPCB that would attach to the pill or heatsink is very flat with only very minor burring around the edge. 30 seconds with sandpaper or a file would leave you with a very good thermal junction.

Here’s a video showing the MCPCB at different angles.

The primary competitor to this board will be the SinkPAD board available from several members. As surprised as I am, these boards are better in one important way. The back side is completely flat and does not have a punched out center slug. This means that the (most important) area directly below the emitter is making contact with the pill/heatsink. This is quite a benefit!

I was curious how much difference the extra contact area would make, so I ran a thermal simulation on two identical MCPCBs - One with the punched out slug and one without. These numbers should only be used as a comparison between the two styles of MCPCB - not as an expectation of what absolute temperature an emitter will run at. I used an ‘infinite’ heat-sink as I only wanted to see the difference in temperature rise through the board with no attention paid to the type of heatsink or host.
SinkPAD style Punched Thermal Pad:

INTL-OUTDOOR Style Flat Bottom

As I expected - There is a measurable difference! Having direct contact with the heat-sink right under the emitter makes a difference.

I’m very pleased with these boards from Intl-Outdoor, and I thank Hank for giving me the opportunity to see them in advance of their public availability. I’ll be buying more of these as soon as they are available.

If I was forced to come up with one complaint, it would be the wire connection pads. I wish they were just a little bit larger. Not a big complaint, but for those less skilled at soldering, it makes for a small connection point.

PPtk

Thanks for doing the test and review PilotPTK. Very valuable information.
Seems like the process of making copper MCPCB’s is improving.
I’am sure it wouldn’t be long before will see them at all our favorite go to stores.
Thanks again!

Thanks for the review PPtk! One question. Can you look closely to see how the slug is attached to the base material? Is it one piece, soldered, pressed in somehow?

This thread has reminded me to hold off on my intl outdoor purchase till these become available

I always wondered why SinkPad pressed it from the bottom. Looks like they would have pressed it from the top like president Lincoln on a penny.

It really appears to be a single piece. I’m not entirely certain how they do it, but it’s a great design.

PPtk

Cool! I’ll be snagging a few to try out.

Milling? Kung Fu magic? Optical illusion? Demon worship? I’d put my money on option 1 or 4.

how does the gold bottom affect thermal transfer?
Also have you tried removing it to see if it has the depression like the sinkpad?

Gold has 3/4 the thermal conductivity of copper… on these things it is not thick enough to matter.

Thanks for such a great review. Lets hope the actual production samples (solid slug design) dont change.

Thanks PilotPTK, these will really sell like hot pancakes and I hope Hank orders enough for everyone, the first batch sold really quick. Great to hear it’s of a good design and function.

Thanks for review…

As far as I can see from where Im sitting. The 16mm Sinkpads are the only copper MCPCBs that can be made into 10mm. The ones from intl-outdoor could be turned into 14 it looks.
But the ones from intl-outdoor will offer quite more bang for the buck. Flat underside and that there are space for access soldier to go away from the center is just icing on the cake!
Looks to be a winner! Cant wait to get mine…

Thanks PilotPTK for the review. Also a big rap to IOS in allowing PilotPTK to review this MCPCB before release.

Interesting, thanks for the review.

Will you do direct lumen comparison tests against the SinkPad?

Cheers!

Good to know that the MPCB bond to the copper substrate is solid, the MPCB on the copper stars i got from ledtech.de were VERY delicate.

Thx PilotPTK.

Thanks for the thorough review. And for the great piece of video art, loved that B-) .

Wow! This sounds very good! Looking forward to these being available! Just hope Hank doesn't underestimate the demand for these! Thanks PilotPTK!

-Garry

Thanks for the in-depth review, PPTk! These look to be a great value. Hopefully Hank has a lot of these in stock…

PilotPtk great review. On your thermal test did you compare with the thicker Sinkpad design or were both models set at 1.5mm?