Copper MCPCB Mods

After reading the results of djozz’ 20mm XML ledboard tests, I was convinced to go ahead with my planned copper MCPCB mod.

I started with drilling 2.5 mm holes in the dielectric layer of the copper MCPCB:

Here’s the front view of the copper MCPCB with the 2.5 mm hole. Yeah the holes are a little off centered but that’s the best I could do with the available tools:

Here’s the back view of the two copper MCPCBs with the holes:

To fill the hole, I used the copper from an AWG 10 wire:

Since the AWG 10 wire is 2.588 mm wide, I filed and sanded it until its fits snugly into the MCPCB holes:

I filed the edge of the copper wire before hammering it to the MCPCB holes. Here’s the front view of the copper MCPCBs with the AWG 10 wire fitted:

And the back view. The first MCPCB has its bottom (with the AWG wire) filed. I did not file the second MCPCB yet for comparison:

Here’s my finished mods beside two copper SinkPads:

And here’s the back view of the modded copper MCPCBs and the copper SinkPads.

Yes my modded copper stars are not as smooth as the SinkPads but I bet they should perform just like SinkPads and Noctigons. :slight_smile:


Great modding work!

Thanks WarHawk-AVG! :slight_smile:

Doh…I edited it beacuse you already mentioned you used Djozz’s method

Either way…excellent work! And nice drill press

Yeah no problem. The drill press isn’t mine. I just requested a friend who has one to drill the holes for me. :bigsmile:

I’ll be doing the same with my aluminum MCPCBs and based on the results of djozz’ tests, I don’t think I’ll be needing to buy SinkPads or Noctigons for XM-L anymore. The dielectric strip of XP stars are very narrow and I don’t think I can drill a hole without messing the positive and negative contact points so I’ll have to try it yet. :slight_smile:

Good mod! Glad to see more budget mods around.

I never see single core wire that large around here. Every home wiring seem to have multiple smaller cores, probably to prevent AC skin effect. So I cannot do this mod without the material.

But I do look forward to see your aluminium version - that will be ultra-cheap mod with highest gain per $.

Thanks Pulsar!

There’s plenty of those single core wires around here and they’re usually used in the electrical connections (lights, AC outlets, etc) of our homes. Actually I just ‘salvaged’ that wire from an AC outlet of a room which was destroyed by Haiyan last November. We need to ‘rewire’ before our electric cooperatives agree to re-energize our homes so I’m sure I won’t run out of AWG 10 single cores for my mods. :stuck_out_tongue:

Yes I’ll post my modified aluminum MCPCBs once done. My copper MCPCBs ordered from eBay won’t arrive till next month so I have all the time to mod my aluminum stars. :slight_smile:

Well done, it is nice to see people even more budget-minded than me, and less lazy :-)

LOL! Thanks djozz. Without your tests, I couldn’t have done it. :slight_smile:

Sliced fingers in 3, 2, 1, ...

That pic just reminds me of some of my own mistakes.. Would be better to secure the star with two screws (or anything else than your fingers) if/when the drill bit gets stuck. ;)

Other than that, thanks for sharing. Seems like a good method for enhancing non-conductive copper stars. :)

You’re absolutely right!

This post left me pondering for a while. If the drill can go through that copper then it can certainly go through all my fingers like hot knife through butter. :open_mouth:

The copper star also gets very hot during drilling. One wrong move can certainly lead to disaster. :zipper_mouth_face:

Thank you the for pointing this out. Better safe than sorry. :beer:

Nice work Nightbird. I think some people assume you did this because you are cheap. I do things like this too but for different reasons:

  1. There is a certain joy in building something for the lowest cost possible.
  2. Trying something new (to me) just to see if I can do it.
  3. Curious how it will work.
  4. OK, yeah, because I am cheap. I save the good stuff for high current projects

Of course, the amount of time invested is a cost, but this is a hobby and not a business. I'm curious why you think you did this particular mod.

It looks like you may have scraped off the dialectic layer. Did you? I would be inclined to leave it (other than the drill hole) because it helps with bringing your copper plug closer tot he led and because the mcpcb has a copper sheet on top of the dielectric layer that could also facilitate heat conduction.

Nice mod! Resourceful mods like this can be more rewarding than buying pre-fab parts.

If you have a pair of thick jeans or an old leather belt you could buff the stars to a more polished finish.

Yes I attempted to scrap the dielectric layer of one copper MCPCB but did not finish it because I decided to go ahead with this mod. I left the dielectric of the other MCPCB intact.

I long wanted to try this because from what I observed on SinkPads, a rectangle hole is punched in the MCPCB and this is plugged with a rectangular copper piece which fits snugly in the hole. This can be replicated by simply drilling a round hole in the copper MCPCB then plugging the hole with copper. I have AWG 10 single core wire with me so the the best thing to do is drill a hole big enough for the AWG 10 to fit snugly. :wink:

I did all these because I love doing it, because I want to ‘improvise’ and because I want to try things that are new to me. Per djozz’ tests, aluminum SinkPads are not far behind in performance so my next project is doing this same mod to my aluminum MCPCBs. Not that I’ll be able to use all the modded aluminum MCPCBs, many of which are the former stars of some of my lights modded with SinkPads, I just love doing the modding. :slight_smile:

And yes I am cheap! This is a Budget Light Forum after all. :bigsmile:

Thanks Chloe!

Actually I use an old leather belt in ‘maintaining’ the sharpness of my blades. And yes this is very effective in buffing the stars. Thanks for pointing this out. :slight_smile:

  1. wire is used between the main panel and sub panels and also for electric ovens and dryers. Last year someone did this to a triple 20 mm using either #12 or #14 so I tried using it to link a 10mm aluminum mcpcb to a copper plate. I had the same difficulty centering the hole but if you file the edge of the wire before pounding it in you can repair the dam between the pads with fujik or JB.

I simply used the Mechanic Chips Repair Soldering Paste from FastTech to fill up the imperfections after the wire is fitted. I also filed the edge of the wire before inserting it to the hole because this would be very hard to do (without destroying the contact points) once it is already fitted in the MCPCB.

Regarding the triple 20 mm, were they copper or aluminum? Did the mod result to the desired results?

Aluminum and I think so. It was done about the time copper boards were coming around but still no copper triples so someone did the wire mod instead. Machinists like MRsDNF were milling out the center pad and dropping the star over a custom heat sink with a raised center pad.

Cool idea about doing this to aluminum stars for future projects. I bet this mod can be done pretty quick after you do a couple.

Nice tip about polishing with leather or jeans Chloe. Gotta keep that one in mind.

~.080" holes drilled, top & bottom of holes chamfered:

12AWG pieces are a light press fit. Clean off all the solder on the topside so it can be laid down flat, then hammer the pins from the backside only - that way the LED side won't need any filing or sanding afterwards.

Before riveting:


The chamfer on both sides of the holes lets the copper spread out and fill in the space, which leaves a flange on either side that locks the pins in forever.