Worth trying. It’s already broken, you can’t really make it much worse. It’d probably work, and worst case you’re back where you started & paying for expensive shipping.

Copper or silver-based should be lower resistance. These conductive paints tend not to be very conductive, the carbon stuff is essentially making a thin-film carbon composition resistor. Good for repairing rear window defroster heating elements, not so great as a 0-ohm trace in a keyboard. For short (<1cm) wires it’s usually not too bad, but with the amount of damage I’m not sure you’ll be able to repair the thing.

It looks like it might be from a Model M-style keyboard. Unicomp sells those.

We’ve had open-source chip design software since the 1980s. Magic VLSI, for example. There are quite a few OSS tools for various parts of the chip design process.

Also bleeding-edge processes mean smaller, thinner gates. That’s what gives them the fast switching speeds, but it reduces the max allowable voltage. For parts that need to handle more than 1.8V or so a modern 5nm process will just end up using bigger gates than the process is optimized for. May as well go with an older process (bigger minimum gate size) that’s better suited to switching the voltage needed. For Bosch (automotive parts, power tools, etc) they’re making a lot of parts with really big output transistors (switching 14V, 48V, etc) and not super high-performance processors.

The big disadvantage with particularly old processes is that they used smaller wafers. So fewer chips per wafer processed, meaning lower overall yields and higher price/chip. The switch from 200mm wafers to 300mm in 1999 meant the wafer area increased by a factor of 2.25! 300mm wafers also required fully-automated factories due to the weight of a wafer carrier (a front opening wafer pod, or FOUP, is 7-9kg when loaded with 25 wafers), which save on labor costs. So processes older than 1999 (around the 180nm node) are sometimes not worth it even for power electronics.

That is an excellent source.

It’s dielectric (non-conductive) not dialectic (talking).

Everything Facebook touches really does evoke horror!

Threads (1984). Still one of the most realistically possibje horror films ever made. The BBC banned its re-airing for 40 years due to being too disturbing.