Superconductor means low resistance. Low resistance means less loss due to heat on a wire. Room temperature superconductor also means more efficient magnets for motors, coils, ending up in cars, MRI machines, etc.
I'm imagining a future where a superconducting layer on a PCB is just another checkbox you can choose when ordering small runs of boards.
[ ] 1 oz copper
[ ] 2 oz copper (+$2)
[X] 10 micron LK-99 (+$10)
Another thought - I think the first place we'll see this widely rolled out is in IC's (waiting for the Asianometry video on it). IC's are already planar, they're small so exotic materials aren't a big contributor to costs, and they're very power dense. Replacing a metal layer with a superconducting one could enable greater gate density and potentially significant improvements in efficiency. I don't know by how much because switching losses are probably where most energy is dissipated, but it's an incremental change that seems compatible with the process.
Perhaps it will be like a "tape" laid down with the proper orientation for each conductor. Perhaps you'll need separate north-south and east-west and maybe diagonal layers with special attention to inter-layer connections.
(The EE I worked with later didn't believe me. See https://en.wikipedia.org/wiki/Superconducting_magnet#Persist... and note that the loss was due to details of magnetic superconductors, not superconductors in general)
> Experiments have demonstrated that currents in superconducting coils can persist for years without any measurable degradation. Experimental evidence points to a lifetime of at least 100,000 years. Theoretical estimates for the lifetime of a persistent current can exceed the estimated lifetime of the universe, depending on the wire geometry and the temperature. In practice, currents injected in superconducting coils have persisted for more than 27 years (as of August 2022) in superconducting gravimeters.
Thanks to everyone. I understand this much better.