How I got 5 direct bond Cu 14mm rounds for <$4

I have been waiting on these boards from ebay seller LCK-LED (also LCK-LED.com) with the goal of the cheapest direct bond Cu boards. They are not sold as direct bond and I wasnt expecting it, I was planning on converting them, doing it this way they cost <$4 for 5 of them plus a little time. I ordered on 4/26 and they arrived sometime within the last 5 days (not sure the exact day as we dont always check the mail box.

the first thing I noticed were they were pressed downward so the edges bend up (the right way). sorry for the bad quality pic but you can see the corner bends up (down in photo)

So first thing was to remove the pad and mask below, I cut along the edges with a sharp knife and then scratched it off

then apply solder paste to center pad, you need some extra because its filling in all that space

heat

Then wick away the excess

and finally, re heat to make it smooth

I plan to test a converted one vs a sink pad and a non-converted one (and maybe an Al non-direct board if I'm feeling up to it. I have a IR laser thermometer and a DMM that can read mini k-type thermocouples and two t-couple's I can mount). alternately if anyone is already setup to do these sort of tests I would gladly send you a modded one and a stock one for testing. Now obviously I dont expect them to perform as well as a sinkpad/noctigon because on the real ones the copper layer comes up higher and this is just built up with solder but it should be a good amount better than with a mask in there on a non-direct board.

Question…does it really matter if you have a little extra on the center pad?

Alot of work to get it to be so smooth
(I think it would be easier to just cut away the dielectric layer, using the stencil just flow the pad, place the emitter on, then heat it for a reflow…done [excess solder should stick to the pads naturally])

Excellent job though…very clean cuts to get rid of the di-electric layer

Definitely want to see if these cheap boards are worth the time/effort of futzing with rather than just reflow em to sinkpads/noctigons and be done with it

If they turn out close in performance do you (in your opinion) would it be worth it

I was hoping you could make it out in the pic’s better but the traces on these boards are really thick, I’m pretty happy with them for the money, I wouldnt use one in a high power build but I’m sure they’ll be good for ~4A or so and give a lumen increase over Al too. They are also one of the few options for 14mm boards and no real direct bond board offer that size, plus they’re .5mm thinner than sinkpad’s too. I’ll be putting one in my EDC quark as soon as I get a chance.

Worth it, probably not, your paying $1.25 a board, you can get the real thing for $2.09 right now so your not even saving a buck each plus the solder it takes and your time, depending on how you feel about that. Will I use them on other people’s builds and sell them as the same thing as a sinkpad/noctigon, of course not, its just not worth $.90 but I’ll do it for my own use because I dont mind the time it takes, its a hobby afterall and I build a lot of lights that just sit,I just build them to build them so I dont need the absolutely best performance, still tho not because of the cost savings, thats just an added bonus.

I guess its a matter of work. If you need 14mm and don’t want to grind down a 16mm board, OK. Other than that, depending on how many you buy, you can get Noctgons for as low as 99¢ each.

Check out djozz’s results here

I know I have a few of the cheap copper boards lying around, & will be using the cutaway method with them.

A lot easier to cut away the DE layer than turn down a board. Nice mod.

I want to see if the ” stinkpad ” has any noticeable affect

<$4/5= <$.80, not $1.25 and for a size not readily available otherwise is a great idea.

I’ve done it like that before, I wonder how much, in any; the copper “slug” helps over the way i did it with just solder.

Finished 3 of them. The last two stock ones are for testing, one for me and hopefully one of each for someone who does similar testing already and is setup for it. I was thinking about not filling them with solder first but doing so allows me to clean it up, they’re pretty straight but the first one did need a little work, there wasn’t continuity or anything that bad but I had toxic a few spots.

I’ll be putting one in my Quark QP2L-X burst mode tonight with a warm white XM-L2 T4 7B3 (currently has the emitter on the factory Al board) tonight after I pick up some new tips.