This ‘micro engineering’ is just stunning , all those individual link wires, it makes me wonder how stuff like this is constructed?

very cool stuff! I have seen a good few close up pictures of LED dies and LED filaments without coating however this is the first time I have seen an LED filament/LED die from the side like this

It always does amaze me how they attatch such fine bond wires to diode and other semiconductor junctions...

I do have some movies of the autowelding of the gold wires but you do not see so much due to the small scale and high speed (it only takes a second or two to weld up a whole filament). But if you look for gold ball wirebonding on youtube there are probably some good detailed movies. In fact the speed is even more amazing when you realise that no heat is applied to make the welds - the tips of the gold wires are just osscilated at high frequency against the chip surface, and frictional forces create the heat to fuse the metals together.

One of my mates used to work for the semiconductor company Diodes, and some of the processes involved to make things we take for granted like a semiconductor package which you can buy for next to nothing is staggering!

I'm amazed by how delicate things like this are made at such speed! How thick is that PN semiconductor junction where the light is produced?

PCB designers are also the unsung heroes of the modern world too, especially when your talking complex multi-layer boards!
I’d guess the thickness of the substrate is exactly half a gnat’s cock

Yes, microchips are another amazing piece of electrical engineering, but credit must also go to the machines that have been designed to make them

LED get's some stick but I really am fascinated by the sheer engineering that goes into making them, and they are only getting better.

I have to agree, LED technology is maturing to become every bit as respectable as traditional light source technologies - just a shame they are so easy to make that anyone can do it and compete to death with each other until there is no margin left and we have the race to the bottom in terms of cost, which makes the quality suffer. The PN junction is only a few hundred nanometres thick, I will make another side photo in the electron microscope to reveal this and some other microscopic features far too small to see in this image.