[uSoldering]

I think with the Image->CAD data you could hack together something resembling a die-bond machine to automate the process. A flying probe would need two heads on both sides for full coverage of continuity, and some algorithms to probe multiple times with micro-offsets to deal with near-hits and bad connection hits. You could also monitor the probe heads for changes in capacitance to infer the quality of the probe hit.

[archi42]

I was also surprised not to see a flying probe system - I would expect this to be viable with modern 3D printer motion & control systems, but obviously this is highly non-trivial and has lots of mean details in the mechanical, electronics and software domains to solve.

I did not think of a die-bond machine (I suppose it bonds a wire to each pad instead of you doing it by hand?), but of course that also makes sense. And at least the motion system is much simpler.

A first step/experiment could be to automate creation of the gnd net. For that you only need a single tool head, meaning you can repurpose mostly any 3D printer motion system; for small increments, this could (later) happen during the die-bond process or become a precursor to a flying probe tool head. Of course I can not judge if that's a worthy investment of your time, or if you would enjoy building something like this ;)

Anyway, the effort, skill and dexterity are amazing! Spending 3 weeks soldering 1917 tiny leads seems to be just the icing on the cake :)