Google search 500W hot plate, or see ebay here: https://www.ebay.com/itm/226269868371
Lots of ali stuff is blocked in germany.
Thanks, I also found a lot of those a lot cheaper on Aliexpress now (maybe, Aliexpress costs are a bit random, could be different once you proceed to checkout)
The reason I say its FPC is because you can see the white tracks on the back. I can't see that happening with aluminum, it should be silver.
JLC does 0.1 to 0.2mm FPC, you could probably find thicker and it would be quite stiff.
How many watts dissipation are we talking? The clive one did not get warm at all, but was only ~2.5W.
A single PCB (about 7mm x 150mm) will be about 4W, so a lot more heat than the one Clive disassembled while being a lot smaller. But I think the LEDs are quite efficient, I remember I calculated with the spectrum given in the datasheet the theoretical maximum lm/W and the LEDs reached a little over 60% of that. Considering some light will be absorbed by the PCB and losses in the traces and the two (very small resistors), it will be about 2W of heat.
As JLCPCB has a greyed-out option for 0.4mm aluminum PCBs, I contacted them and asked under what circumstance 0.4mm aluminum PCB is available, the answer was not at all at the moment. I assume the other companies with online ordering use the same fab to produce the aluminum PCBs, considering all other options are the same and they cannot give a quote for 0.4mm/0.6mm.
I just checked my old order and the PCBs I tested for bending are actually 1.2mm not 1mm, so maybe 0.8mm does work. I think I'll order them in 0.8mm aluminum, the stencil is the most expensive part anyway, so if it doesn't work I'll order some flex pcbs and already have the stencil.