@User: The problem is that we don't have capacitance values from SkyWater other than the complicated captables entries for Cadence and the Calibre PEX equations---both are difficult to pull a simple number from. The parallel plate capacitance can be calculated from the inter-layer dielectric constants and the inter-layer distances. However, calculating fringe capacitance with some "standard simplifications" failed to produce anything meaningful, so I need a field equation solver for that. I have a colleague who has worked up a setup for "space" (TU Delft, available on github), although "space" prohibits more than 3 dielectric layers and doesn't handle sidewall dielectrics, so some simplifying assumptions need to be made there, too. I have per-layer resistivity values in the techfile for magic, but I agree we need to publish some of this stuff. It is not clear to me what documentation we have that is publishable; I think maybe none of it is publishable as-is, so we will have to reformat it and post it as we go. I made the layer stack drawing because it was information that we did not have from SkyWater and I was making a visual interpretation of one of the QRC setup files.

@User Did you release these somewhere? (qrc files / cap tables) I can't seem to find them.

@mehdi: Not as files. I wrote up some figures and put them in https://docs.google.com/spreadsheets/d/176OcP2h_TT_pDP2-zBLijlgFUP38LVgMQPlDtpLcrsk/edit?ts=5eff8387#gid=1059412464 . There are more figures and equations in my original xcircuit file with the stackup; I can post that if you like.

@Tim Edwards it would good to take a look at those as well (although I don't have many cycles rn)

(xcircuit file)

@Tim Edwards what do you use to read this file?

xcircuit. But it's postscript, so gs/gv will read it, or you can run it through ps2pdf.