So what are these? There's a hole in the middle but is that middle pad directly connected to the core?
http://www.kaidomain.com/product/details.S022273
its a hole, so you can see what`s underneath it! makes sense, doesnt it?
I believe that may be compatible with these PowerPeg style heatsink solutions.
Dave talks about them here on the Eevblog
http://www.eevblog.com/forum/blog/eevblog-677-mailbag/
Pre-drilled for your own DTP solution? Find an appropriately-heavy piece of copper wire and press-fit into the hole, then lap both sides smooth.
Second option; Fill with excessive amounts of thermal paste, preferably the grease-type.
Third option; when you reflow your emitter, use enough solder to completely plug the hole.
Counter-sink the back, then fill with solder to keep the emitter from falling off?
Through-Die drill for retaining bolt?
So the emitter can shine in both directions at once?
It also takes care of the uplift a pip left by lathe operations cause.
You can also use this to ensure centering the LED.
I suspect the punch operation doesn’t bode well where there is uplift on the emitter side if it is not completely flush.
It makes me recall comfychair’s mod - press fit a thick copper wire into the hole and you have a DTP board, no?
Reminds me of what NightCrawl did I think in late 2012.
Its the new light weight star for the weight conscious person.
I have no idea way that did that (cost savings maybe, i suspect the material savings is less then the increase in production cost) but it is a way to make a cheap sinkpad/noctigon substitute, fill it with solder (and not thermal compound)
To fill the hole with solder you need special flux, otherwise the solder simply won’t stick to the aluminium.