If I thought the COB LED panel was big the last time, then this is now officially the biggest I've ever seen. It's based on a solid panel of aluminium with a PCB layer laminated on. The COB aspect (Chips On Board) indicates the way the bare LED chips are bonded directly to the PCB layer and bond wires attached between the chip contacts and the PCB. The board has a dam of silicone piped round the desired outline and is then flooded with a layer of phosphor loaded silicone gel to protect the LEDs and convert the blue light from the chips to white.
This panel has a massive 600 LED chips on it in a 30 by 20 array.
The LEDs are wired in rows of 30 parallel chips in series groups of four rows to make up the desired 12V rating. There's no current limiting so any voltage fluctuation will result in wide intensity variation and any cable resistance will have an effect on the current through the panel.
The LEDs are not well matched on this panel so there will be a wide current difference between the chips and it could damage them if run at high current.
The PCB bus bars are arranged to provide as equal a resistive path to all LEDs as possible to ensure that track resistance does not cause an intensity variation.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.